Note: Descriptions are shown in the official language in which they were submitted.
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THERAPEUTIC COMPOSITIONS INCLUDING
MITOCHONDRIAL FISSION INHIBITOR PEPTIDES,
VARIANTS THEREOF, AND METHODS OF USING THE
SAME TO TREAT AND PREVENT MITOCHONDRIAL
DISEASES AND CONDITIONS
TECHNICAL FIELD
[0001] Disclosed herein are methods and compositions related to the treatment
and/or amelioration of diseases and conditions comprising administration of
mitochondrial fission inhibitor peptides, and/or derivatives, analogues, or
pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*). In
particular, the
present technology relates to administering an effective amount of
mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) to a subject in need
thereof to
prevent or treat a disease or medical condition, reduce risk factors
associated with a
disease or medical condition, and/or reducing the severity of a medical
disease or
condition.
BACKGROUND
[0002] The following description is provided to assist the understanding of
the
reader. None of the information provided or references cited is admitted to be
prior
art to the present technology.
[0003] Mitochondria are sometimes described as cellular "power plants" because
among other things, mitochondria are responsible for creating more than 90% of
the
energy needed by the body to sustain life and support growth. Mitochondria are
organelles found in almost every cell in the body. In addition to making
energy,
mitochondria are also deeply involved in a variety of other activities, such
as making
steroid hormones and manufacturing the building blocks of DNA. Mitochondrial
failure causes cell injury that leads to cell death.
[0004] Mitochondrial diseases are nearly as common as childhood cancer.
Approximately one in 4,000 children born in the United States every year will
develop a mitochondrial disorder by age 10. In adults, many diseases of aging
have
been found to have defects of mitochondrial function. These include, but are
not
CA 02881746 2015-02-13
limited to, type 2 diabetes, Parkinson's disease, Alzheimer's disease, and
cancer. In
addition, select drugs can injure the mitochondria.
[0005] There are multiple forms of mitochondrial disease. Mitochondrial
disease
can manifest as a chronic, genetic disorder that occurs when the mitochondria
of the
cell fails to produce enough energy for cell or organ function. Indeed, for
many
patients, mitochondrial disease is an inherited condition that runs in
families (genetic).
Mitochondrial disease is inherited in a number of different ways. There is
autosomal
inheritance, mtDNA inheritance as well as a combination thereof. For example,
mutations of genes encoding Complex I ¨ Complex V can contribute to
mitochondrial
disease in humans. An uncertain percentage of patients acquire symptoms due to
other factors, including mitochondrial toxins.
[0006] Mitochondrial disease presents very differently from individual to
individual. There is presently no cure for mitochondrial-based disease.
Treatment is
generally palliative to improve disease symptoms.
SUMMARY
[0007] In one aspect, the present disclosure provides a method for treating or
preventing a mitochondrial disease or disorder in a subject in need thereof,
comprising administering to the subject a therapeutically effective amount of
a
mitochondrial fission inhibitor peptide, or a derivative, analogue, or
pharmaceutically
acceptable salt thereof (e.g., P110 and/or P110*).
[0008] In some embodiments, the mitochondrial fission inhibitor peptide is
selected
from the group consisting of: STQELLRFPK (SEQ ID NO:4); KLSAREQRD (SEQ
ID NO:5); DLLPRGS (SEQ ID NO:10); DLLPRGT (SEQ ID NO:3); SVEDLLKFEK
(SEQ ID NO:7); KGSKEEQRD (SEQ ID NO:8); DFLPRGS (SEQ ID NO:11); and
ELLPKGS (SEQ ID NO:6). In some embodiments, the present disclosure provides a
mitochondrial fission inhibitor peptide comprising Formula I:
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R7
R6
R5
'Cy R3 0 R11 R3 0
0 R4 R3
I ,14
0 ( CH2)n R3 0
R12 R13
, I 0
R10
CH2 m R3 0 R5
R1
Formula I
or stereoisomers thereof, tautomers thereof; solvates thereof, and
pharmaceutically acceptable salts thereof; wherein
Ri is -COORa or -CONRaRa;
R2 and Ri4 independently are -H, -OR', -NRaRa, -NRaC(0)0Rb, -
NRaC(0)NRaRa, -C(0)Ra, -Ra or a nitrogen-containing saturated or unsaturated
heterocyclyl group;
R3 at each occurrence is independently H or C1-4 alkyl;
R4 and R5 are independently a substituted or unsubstituted alkyl, alkenyl,
alkynyl, cycloalkyl, cycloalkylalkyl, aryl or aralkyl group;
R6 is -H;
R7 is -H, -OR', -NRaRa, a substituted or unsubstituted alkyl, cycloalkyl,
cycloalkylalkyl, or alkaryl group; or alternatively, R6 and R7 together are a
phenyl
group;
R8 is a ¨H or ORa;
R9 is -H, a substituted or unsubstituted alkyl or alkenyl group;
Rio is a ¨NRcRc, -C(NRe)NRcRe, -NWC(NRc)NRcRe, -NWC(0)NRcRe;
Rii is ¨H, -CN, a Ci-C2 unsubstituted alkyl, or cyclopropyl group;
R12 is -H, ORc,-NReRc, or a substituted or unsubstituted alkyl, alkenyl, or
cycloalkyl group;
R13 is ¨H or a substituted or unsubstituted alkyl group, or alternatively, R12
and Ri3 together are a 5- or 6-member saturated or unsaturated heterocyclyl
group;
IV at each occurrence is independently -H, a substituted or unsubstituted
alkyl,
alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, alkaryl, or aralkyl
group;
Rb at each occurrence is independently a substituted or unsubstituted alkyl,
alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, alkaryl, or aralkyl
group;
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RC at each occurrence is independently -H, or a Cl- C4 substituted or
unsubstituted alkyl group;
Cx and Cy are connected by a carbon-carbon single bond or carbon-carbon
double bond;
m is 1,2, or 3;
n is 1, 2, 3, 4, or 5; and
s is 0 or 1.
[0009] In some embodiments of the method, the mitochondrial disease or
disorder is
selected from the group consisting of Alexander disease, Alpers Syndrome,
Alpha-
ketoglutarate dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia
with spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia,
GRACILE
Syndrome, BjOrnstad Syndrome, Leigh Syndrome, mitochondrial complex III
deficiency nuclear type 1 (MC3DN1), combined oxidative phosphorylation
deficiency
18 (COXPD18), Thiamine-responsive megaloblastic anemia syndrome (TRMA),
Pearson Syndrome, HAM Syndrome, Ataxia, Cataract, and Diabetes Syndrome,
MELAS/MERRF Overlap Syndrome, combined oxidative phosphorylation
deficiency-14 (COXPD14), Infantile cerebellar-retinal degeneration (ICRD),
Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10 deficiency-1
(C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation (LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with
optic
atrophy (SPAX4), progressive external ophthalmoplegia with mitochondrial DNA
deletions autosomal dominant type 5 (PEOA5), mitochondrial complex III
deficiency
nuclear type 2 (MC3DN2), episodic encephalopathy due to thiamine
pyrophosphokinase deficiency/Thiamine Metabolism Dysfunction Syndrome-5
(THMD5), Spinocerebellar ataxia-28 (SCA28), autosomal dominant cerebellar
ataxia,
deafness, and narcolepsy (ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar
ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss
(CAPOS)
Syndrome, spinocerebellar ataxia 7 (SCA7), Barth Syndrome, Biotinidase
deficiency,
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gyrate atrophy, Syndromic Dominant Optic Atrophy and Deafness (Syndromic
DOAD), Dominant Optic Atrophy plus (D0Aplus), Leber's hereditary optic
neuropathy (LHON), Wolfram Syndrome-1 (WFS1), Wolfram Syndrome-2 (WFS2),
Age-related macular degeneration (ARMD), Brunner Syndrome, Left ventricular
noncompaction-1 (LVNC1), histiocytoid cardiomyopathy, Familial Myalgia
Syndrome, Parkinsonism, Fatal infantile cardioencephalomyopathy due to
cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP) deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency, cardiomyopathy + encephalomyopathy, mitochondria' phosphate
carrier
deficiency, infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency (CEMCOX2), 0-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency,
ECHS1) deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated
cardiomyopathy with ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12
(MTDPS12), cardiomyopathy due to mitochondrial tRNA deficiencies,
mitochondria'
complex V (ATP synthase) deficiency nuclear type 1 (MC5DN1), combined
oxidative
phosphorylation deficiency-8 (COXPD8), progressive leukoencephalopathy with
ovarian failure (LKENP), combined oxidative phosphorylation deficiency-10
(COXPD10), combined oxidative phosphorylation deficiency-16 (COXPD16),
combined oxidative phosphorylation deficiency-17 (COXPD17), combined oxidative
phosphorylation deficiency-5 (COXPD5), combined oxidative phosphorylation
deficiency-9 (COXPD9), carnitine acetyltransferase (CRAT) deficiency,
carnitine
palmitoyltransferase I (CPT I) deficiency, myopathic carnitine deficiency,
primary
systemic carnitine deficiency (CDSP), carnitine palmitoyltransferase II (CPT
II)
deficiency, carnitine-acylcarnitine translocase deficiency (CACTD), cartilage-
hair
hypoplasia, cerebrotendinous xanthomatosis (CTX), congenital adrenal
hyperplasia
(CAH), megaconial type congenital muscular dystrophy, cerebral creatine
deficiency
syndrome-3 (CCDS3), maternal nonsyndromic deafness, maternal nonsyndromic
deafness, autosomal dominant deafness-64 (DFNA64), Mohr-Tranebjaerg Syndrome,
Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGS SS, diabetes, Dimethylglycine dehydrogenase
deficiency (DMGDHD), Multiple Mitochondria' Dysfunctions Syndrome-1
(MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple
Mitochondrial Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy
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associated with mitochondrial Complex II deficiency, encephalopathies
associated
with mitochondrial Complex I deficiency, encephalopathies associated with
mitochondrial Complex III deficiency, encephalopathies associated with
mitochondrial Complex IV deficiency, encephalopathies associated with
mitochondrial Complex V deficiency, hyperammonemia due to carbonic anhydrase
VA deficiency (CA5AD), early infantile epileptic encephalopathy-3 (EIEE3), 2,4-
Dienoyl-CoA reductase deficiency (DECRD), infection-induced acute
encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE), hypomyelinating
leukodystrophy (HLD4), exocrine pancreatic insufficiency, dyserythropoietic
anemia
and calvarial hyperostosis, Glutaric aciduria type 1 (GA-1), glycine
encephalopathy
(GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-hydroxyacyl-CoA
dehydrogenase deficiency, familial hyperinsulinemic hypoglycemia (FHH),
hypercalcemia infantile, hyperornithinemia-hyperammonemia-homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion
Body Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous myopathies with anti-mitochondrial antibodies, necrotizing
myopathy
with pipestem capillaries, myopathy with deficient chondroitin sulfate C in
skeletal
muscle connective tissue, benign acute childhood myositis, idiopathic orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated myositis, Facioscapulohumeral dystrophy (FSH), familial idiopathic
inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus, Addison disease,
Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS), focal myositis,
autoimmune fasciitis, Spanish toxic oil-associated fasciitis, Eosinophilic
fasciitis,
Macrophagic myofasciitis, Graft-vs-host disease fasciitis, Eosinophilia-
myalgia
Syndrome, perimyositis, isovaleric acidemia (IVA), Kearnes-Sayre Syndrome
(KSS),
2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle Muscular Dystrophy
Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-Methylcrotonyl-
CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller Syndrome,
Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular atrophy
syndrome, rigid spine syndrome, severe myopathy with motor regression,
Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia,
MNGIE, MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked
distal spinal muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF,
progressive external ophthalmoplegia with myoclonus, deafness and diabetes
(DD),
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multiple symmetric lipomatosis, Myopathy with Episodic high Creatine Kinase
(MIMECK), Epilepsia Partialis Continua, malignant hyperthermia syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
medication-, drug- or toxin-induced myoglobinuria, mitochondrial disorder-
associated
myoglobinuria, hypokalemic myopathy and rhabdomyolysis, muscle trauma-
associated myoglobinuria, ischemia-induced myoglobinuria, infection-induced
myoglobinuria, immune myopathies associated with myoglobinuria, Myopathy,
lactic
acidosis, and sideroblastic anemia (MLASA), infantile mitochondrial myopathy
due
to reversible COX deficiency (MMIT), Myopathy, Exercise intolerance,
Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder, maternally-inherited mitochondrial myopathies, myopathy with lactic
acidosis, myopathy with rhabdomyolysis, Myopathy with cataract and combined
respiratory chain deficiency, myopathy with abnormal mitochondrial
translation,
Fatigue Syndrome, myopathy with extrapyramidal movement disorders (MPXPS),
glutaric aciduria II (MADD), primary C0Q10 deficiency-1 (C0Q10D1), primary
CoQ10 deficiency-2 (C0Q10D2), primary CoQ10 deficiency-3 (C0Q10D3), primary
CoQ10 deficiency-5 (C0Q10D5), secondary C0Q10 deficiency, autosomal dominant
mitochondrial myopathy, myopathy with focal depletion of mitochondria,
mitochondrial DNA breakage syndrome (PEO + Myopathy), lipid type mitochondrial
myopathy, multiple symmetric lipomatosis (MSL), N-acetylglutamate synthase
(NAGS) deficiency, Nephronophthisis (NPHP), omithine transcarbamylase (OTC)
deficiency, neoplasms, NARP Syndrome, paroxysmal nonkinesigenic dyskinesia
(PNKD), sporadic PEO, maternally-inherited PEO, autosomal dominant progressive
external ophthalmoplegia with mitochondrial DNA deletions-3 (PEOA3), autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
2
(PEOA2), autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO +
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal dominant progressive external ophthalmoplegia-6 (PEOA6), PEO +
Myopathy and Parkinsonism, autosomal recessive progressive external
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ophthalmoplegia (PEOB), Mitochondrial DNA Depletion Syndrome-11 (MTDPS11),
PEO with cardiomyopathy, PEPCK deficiency, Perrault Syndromes (PRLTS),
propionic acidemia (PA), pyruvate carboxylase deficiency, pyruvate
dehydrogenase
El-alpha deficiency (PDHAD), pyruvate dehydrogenase El-beta deficiency
(PDHBD), dihydrolipoamide dehydrogenase (DLD) deficiency, pyruvate
dehydrogenase phosphatase deficiency, pyruvate dehydrogenase E3-binding
protein
deficiency (PDHXD), mitochondrial pyruvate carrier deficiency (MPYCD),
Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-chain acyl-
CoA
dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA transferase (SCOT)
deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC), Very
long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-dependent
rickets type lA (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues, germanium myopathy, Parkinsonism and mitochondrial Complex I
neurotoxicity due to trichloroethylene, valproate-induced hepatic failure,
neurodegeneration with brain iron accumulation-4 (NBIA4), Complex I
deficiency,
Complex II deficiency, Complex III deficiency, Complex IV deficiency, Complex
V
deficiency, Cytochrome c oxidase (COX) deficiency, combined complex I, II, IV,
V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3), combined oxidative phosphorylation deficiency-4 (COXPD4), combined
oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11), combined oxidative phosphorylation deficiency-12 (COXPD12),
combined oxidative phosphorylation deficiency-13 (COXPD13), combined oxidative
phosphorylation deficiency-15 (COXPD15), combined oxidative phosphorylation
deficiency-16 (COXPD16), combined oxidative phosphorylation deficiency-19
(COXPD19), combined oxidative phosphorylation deficiency-20 (COXPD20),
combined oxidative phosphorylation deficiency-21 (COXPD21), fumarase
deficiency,
HMG-CoA synthase-2 deficiency, hyperuricemia, pulmonary hypertension, renal
failure, and alkalosis (HUPRA) Syndrome, syndromic microphthalmia-7,
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pontocerebellar hypoplasia type 6 (PCH6), Mitochondrial DNA Depletion Syndrome-
9 (MTDPS9P), and Sudden infant death Syndrome (SIDS).
[0010] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered one, two, three, four, or five times per day. In some embodiments
of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered more than five times per day.
[0011] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered every day, every other day, every third day, every fourth day,
every fifth
day, or every sixth day. In some embodiments of the method, the mitochondrial
fission inhibitor peptide composition (e.g., P110 and/or P110*) is
administered
weekly, bi-weekly, tri-weekly, or monthly.
[0012] In some embodiments, the mitochondrial fission inhibitor peptide
composition (e.g., P110 and/or P110*) is administered for a period of one,
two, three,
four, or five weeks. In some embodiments, the mitochondrial fission inhibitor
peptide
composition (e.g., P110 and/or P110*) is administered for six weeks or more.
In
some embodiments, the mitochondrial fission inhibitor peptide composition
(e.g.,
P110 and/or P110*) is administered for twelve weeks or more. In some
embodiments, the mitochondrial fission inhibitor peptide composition (e.g.,
P110
and/or P110*) is administered for a period of less than one year. In some
embodiments, the mitochondrial fission inhibitor peptide composition (e.g.,
P110
and/or P110*) is administered for a period of more than one year.
[0013] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered daily for one, two, three, four or five weeks. In some
embodiments of
the method, the mitochondrial fission inhibitor peptide composition (e.g.,
P110 and/or
P110*) is administered daily for less than 6 weeks. In some embodiments of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered daily for 6 weeks or more. In other embodiments of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered daily for 12 weeks or more.
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[0014] In some embodiments of the method, the subject displays abnormal levels
of
one or more energy biomarkers compared to a normal control subject. In some
embodiments, the energy biomarker is selected from the group consisting of
lactic
acid (lactate) levels; pynivic acid (pyruvate) levels; lactate/pyruvate
ratios; total,
reduced or oxidized glutathione levels; reduced/oxidized glutathione ratios;
total,
reduced or oxidized cysteine levels; reduced/oxidized cysteine ratios;
phosphocreatine
levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels; NAD or NADP
levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized coenzyme Q
(CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized cytochrome C
levels;
reduced cytochrome C levels; oxidized cytochrome C/reduced cytochrome C ratio;
acetoacetate levels; beta-hydroxy butyrate levels; acetoacetate/ beta-hydroxy
butyrate
ratio; 8-hydroxy-2'-deoxyguanosine (8-0HdG) levels; levels of reactive oxygen
species; oxygen consumption (V02), carbon dioxide output (VCO2), and
respiratory
quotient (VCO2/V02). In some embodiments of the method, the lactate levels of
one
or more of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular
fluid are
abnormal compared to a normal control subject. In some embodiments of the
method,
the pyruvate levels of one or more of whole blood, plasma, cerebrospinal
fluid, or
cerebral ventricular fluid are abnormal compared to a normal control subject.
In some
embodiments of the method, the lactate/pyruvate ratios of one or more of whole
blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid are abnormal
compared to a normal control subject. In some embodiments of the method, the
total,
reduced or oxidized glutathione levels of one or more of whole blood, plasma,
lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are abnormal
compared
to a normal control subject. In some embodiments of the method, the total,
reduced or
oxidized cysteine levels of one or more of whole blood, plasma, lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the reduced/oxidized
glutathione ratios of one or more of whole blood, plasma, lymphocytes,
cerebrospinal
fluid, or cerebral ventricular fluid are abnormal compared to a normal control
subject.
In some embodiments of the method, the reduced or oxidized cysteine ratios of
one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular fluid are abnormal compared to a normal control subject.
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[0015] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) is
administered
orally, intranasally, intrathecally, intraocularly, intradermally,
transmucosally,
iontophoretically, topically, systemically, intravenously, subcutaneously,
intraperitoneally, or intramuscularly. In some embodiments of the method, the
subject is human.
[0016] Additionally or alternatively, in some embodiments of the method, the
symptoms of the mitochondrial disease or disorder comprises one or more of
poor
growth, loss of muscle coordination, muscle weakness, neurological deficit,
seizures,
autism, autistic spectrum, autistic-like features, learning disabilities,
heart disease,
liver disease, kidney disease, gastrointestinal disorders, severe
constipation, diabetes,
increased risk of infection, thyroid dysfunction, adrenal dysfunction,
autonomic
dysfunction, confusion, disorientation, memory loss, failure to thrive, poor
coordination, sensory (vision, hearing) problems, reduced mental functions,
hypotonia, disease of the organ, dementia, respiratory problems, hypoglycemia,
apnea, lactic acidosis, seizures, swallowing difficulties, developmental
delays,
movement disorders (dystonia, muscle spasms, tremors, chorea), stroke, and
brain
atrophy.
[0017] Additionally or alternatively, in some embodiments, the method further
comprises separately, sequentially or simultaneously administering an
additional
therapeutic agent to the subject. In certain embodiments, the additional
therapeutic
agent is selected from the group consisting of: vitamins, cofactors,
antibiotics,
hormones, antineoplastic agents, steroids, immunomodulators, dermatologic
drugs,
antithrombotic, antianemic, and cardiovascular agents.
[0018] In another aspect, the present disclosure provides a method for
modulating
the expression of one or more energy biomarkers in a mammalian subject in need
thereof, the method comprising: administering to the subject a therapeutically
effective amount of a mitochondrial fission inhibitor peptide, or a
derivative,
analogue, or pharmaceutically acceptable salt thereof (e.g., P110 and/or
P110*).
[0019] In some embodiments of the method, the energy biomarker is selected
from
the group consisting of lactic acid (lactate) levels; pyruvic acid (pyruvate)
levels;
lactate/pyruvate ratios; total, reduced or oxidized glutathione levels;
reduced/oxidized
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glutathione ratios; total, reduced or oxidized cysteine levels;
reduced/oxidized
cysteine ratios; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels; oxidized cytochrome C levels; reduced cytochrome C levels; oxidized
cytochrome C/reduced cytochrome C ratio; acetoacetate levels; beta-hydroxy
butyrate
levels; acetoacetate/ beta-hydroxy butyrate ratio; 8-hydroxy-2'-deoxyguanosine
(8-
OHdG) levels; levels of reactive oxygen species; oxygen consumption (V02),
carbon
dioxide output (VCO2), and respiratory quotient (VCO2/V02). In some
embodiments of the method, the lactate levels of one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the pyruvate levels of one
or
more of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular
fluid are
abnormal compared to a normal control subject. In some embodiments of the
method,
the lactate/pyruvate ratios of one or more of whole blood, plasma,
cerebrospinal fluid,
or cerebral ventricular fluid are abnormal compared to a normal control
subject. In
some embodiments of the method, the total, reduced or oxidized glutathione
levels of
one or more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or
cerebral
ventricular fluid are abnormal compared to a normal control subject. In some
embodiments of the method, the total, reduced or oxidized cysteine levels of
one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular fluid are abnormal compared to a normal control subject. In some
embodiments of the method, the reduced/oxidized glutathione ratios of one or
more of
whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular
fluid
are abnormal compared to a normal control subject. In some embodiments of the
method, the reduced or oxidized cysteine ratios of one or more of whole blood,
plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject.
[0020] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered one, two, three, four, or five times per day. In some embodiments
of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered more than five times per day.
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[0021] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered every day, every other day, every third day, every fourth day,
every fifth
day, or every sixth day. In some embodiments of the method, the mitochondrial
fission inhibitor peptide composition (e.g., P110 and/or P110*) is
administered
weekly, bi-weekly, tri-weekly, or monthly.
[0022] In some embodiments, the mitochondrial fission inhibitor peptide
composition (e.g., P110 and/or P110*) is administered for a period of one,
two, three,
four, or five weeks. In some embodiments, the mitochondria' fission inhibitor
peptide
composition (e.g., P110 and/or P110*) is administered for six weeks or more.
In
some embodiments, the mitochondria' fission inhibitor peptide composition
(e.g.,
P110 and/or P110*) is administered for twelve weeks or more. In some
embodiments, the mitochondria' fission inhibitor peptide composition (e.g.,
P110
and/or P110*) is administered for a period of less than one year. In some
embodiments, the mitochondrial fission inhibitor peptide composition (e.g.,
P110
and/or P110*) is administered for a period of more than one year.
[0023] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide composition (e.g., P110 and/or P110*)
is
administered daily for one, two, three, four or five weeks. In some
embodiments of
the method, the mitochondrial fission inhibitor peptide composition (e.g.,
P110 and/or
P110*) is administered daily for less than 6 weeks. In some embodiments of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered daily for 6 weeks or more. In other embodiments of the
method, the mitochondrial fission inhibitor peptide composition (e.g., P110
and/or
P110*) is administered daily for 12 weeks or more.
[0024] In some embodiments of the method, the subject has been diagnosed has
having, is suspected of having, or is at risk of having a mitochondrial
disease or
disorder. In a further embodiment of the method, the subject is human.
[0025] In some embodiments of the method, the symptoms of the mitochondrial
disease or disorder comprises one or more of poor growth, loss of muscle
coordination, muscle weakness, neurological deficit, seizures, autism,
autistic
spectrum, autistic-like features, learning disabilities, heart disease, liver
disease,
13
CA 02881746 2015-02-13
kidney disease, gastrointestinal disorders, severe constipation, diabetes,
increased risk
of infection, thyroid dysfunction, adrenal dysfunction, autonomic dysfunction,
confusion, disorientation, memory loss, failure to thrive, poor coordination,
sensory
(vision, hearing) problems, reduced mental functions, hypotonia, disease of
the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle
spasms, tremors, chorea), stroke, and brain atrophy.
[0026] In some embodiments of the method, the mitochondrial fission inhibitor
peptide (e.g., P110 and/or P110*) is administered orally, intranasally,
intrathecally,
intraocularly, intradermally, transmucosally, iontophoretically, topically,
systemically, intravenously, subcutaneously, intraperitoneally, or
intramuscularly.
[0027] Additionally or alternatively, in some embodiments, the method further
comprises separately, sequentially or simultaneously administering an
additional
therapeutic agent to the subject. In certain embodiments of the method, the
additional
therapeutic agent is selected from the group consisting of: vitamins,
cofactors,
antibiotics, hormones, antineoplastic agents, steroids, immunomodulators,
dermatologic drugs, antithrombotic, antianemic, and cardiovascular agents.
[0028] In another aspect, the present technology provides methods for
treating,
ameliorating or preventing the disruption of mitochondrial oxidative
phosphorylation
in a subject in need thereof, by administering mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) as disclosed herein, the method comprising
administering to
the subject a therapeutically effective amount of a mitochondrial fission
inhibitor
peptide, or a derivative, analogue, or pharmaceutically acceptable salt
thereof (e.g.,
P110 and/or P110*), thereby preventing, ameliorating, or treating
mitochondrial
oxidative phosphorylation, and/or signs or symptoms thereof. In one
embodiment, the
method further comprises the step administering one or more additional
therapeutic
agents to the subject.
[0029] In some embodiments of the method, the subject is suffering from or is
at
increased risk of a disruption of mitochondrial oxidative phosphorylation. In
some
embodiments, the subject is suffering from or is at increased risk of a
disease or
conditions characterized by a genetic mutation which affects mitochondrial
function.
14
CA 02881746 2015-02-13
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 shows the effect that various dysfunctions can have on energy
biomarkers as well as biochemical events that occur within the body. It also
indicates
the physical effect (such as a disease symptom or other effect of the
dysfunction)
typically associated with a given dysfunction. It should be noted that any of
the
energy biomarkers listed in the table, in addition to energy biomarkers
enumerated
elsewhere, can also be modulated, enhanced, or normalized by the mitochondrial
fission inhibitor peptides of the present technology (e.g., P110 and/or
P110*).
RQ=respiratory quotient; BMR=basal metabolic rate; HR (C0)=heart rate (cardiac
output); T=body temperature (preferably measured as core temperature);
AT=anaerobic threshold; pH=blood pH (venous and/or arterial).
[0031] Figure 2A provides a schematic showing regions of homology identified
in
the Drpl (GenBank Acc. No. AAH24590; SEQ ID NO:1) and Fisl (GenBank Ace.
No. NP 057152; SEQ ID NO:2) proteins (adapted from Qi etal., J Cell Sci.
126(3):789-802 (2013)).
[0032] Figure 2B shows representative sequences identified in the homologous
regions of Drpl and Fisl (DLLPRGT, SEQ ID NO:3; STQELLRFPK, SEQ ID NO:4;
KLSAREQRD, SEQ ID NO:5; ELLPKGS, SEQ ID NO:6; SVEDLLKFEK, SEQ ID
NO:7; KGSKEEQRD, SEQ ID NO:8) (adapted from Qi et at., J Cell Sci. 126(3):789-
802 (2013)).
[0033] Figure 2C shows a sequence alignment of the 3 identified homology
regions
of Drpl (Regions 108, 109, 110) and Fisl (Regions 111, 112, 113) (adapted from
Qi
et al., J Cell Sci. 126(3):789-802 (2013)).
DETAILED DESCRIPTION
[0034] It is to be appreciated that certain aspects, modes, embodiments,
variations
and features of the present technology are described below in various levels
of detail
in order to provide a substantial understanding of the present technology. The
definitions of certain terms as used in this specification are provided below.
Unless
defined otherwise, all technical and scientific terms used herein generally
have the
same meaning as commonly understood by one of ordinary skill in the art to
which
the present technology belongs.
CA 02881746 2015-02-13
[0035] All numerical designations, e.g., pH, temperature, time, concentration
and
molecular weight, including ranges, are approximations which are varied (+) or
(-) by
increments of 1.0 or 0.1, as appropriate, or alternatively by a variation of
+/- 10%, or
alternatively 5% or alternatively 2%. It is to be understood, although not
always
explicitly stated, that all numerical designations are preceded by the term
"about".
[0036] Where a range of values is provided, it is understood that each
intervening
value, to the tenth of the unit of the lower limit unless the context clearly
dictates
otherwise, between the upper and lower limit of that range and any other
stated or
intervening value in that stated range, is encompassed within the present
technology.
The upper and lower limits of these smaller ranges may independently be
included in
the smaller ranges, and are also encompassed within the present technology,
subject to
any specifically excluded limit in the stated range. Where the stated range
includes
one or both of the limits, ranges excluding either or both of those included
limits are
also included in the present technology.
[0037] As used in this specification and the appended claims, the singular
forms
"a", "an" and "the" include plural referents unless the content clearly
dictates
otherwise. For example, reference to "a cell" includes a combination of two or
more
cells, and the like.
[0038] As used herein, the "administration" of an agent, drug, or compound to
a
subject includes any route of introducing or delivering to a subject a
compound to
perform its intended function. Administration can be carried out by any
suitable
route, including orally, intranasally, intrathecally, parenterally
(intravenously,
intramuscularly, intraperitoneally, or subcutaneously), intraocularly,
intradermally,
transmucosally, iontophoretically, or topically. Administration includes self-
administration and the administration by another.
[0039] As used herein, the term "amino acid" includes naturally-occurring
amino
acids and synthetic amino acids, as well as amino acid analogues and amino
acid
mimetics that function in a manner similar to the naturally-occurring amino
acids.
Naturally-occurring amino acids are those encoded by the genetic code, as well
as
those amino acids that are later modified, e.g., hydroxyproline, y-
carboxyglutamate,
and 0-phosphoserine. Amino acid analogues refers to compounds that have the
same
basic chemical structure as a naturally-occurring amino acid, i.e., an a-
carbon that is
16
CA 02881746 2015-02-13
bound to a hydrogen, a carboxyl group, an amino group, and an R group, e.g.,
homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium.
Such
analogues have modified R groups (e.g., norleucine) or modified peptide
backbones,
but retain the same basic chemical structure as a naturally-occurring amino
acid.
Amino acid mimetics refers to chemical compounds that have a structure that is
different from the general chemical structure of an amino acid, but that
functions in a
manner similar to a naturally-occurring amino acid. Amino acids can be
referred to
herein by either their commonly known three letter symbols or by the one-
letter
symbols recommended by the IUPAC-IUB Biochemical Nomenclature Commission.
[0040] As used herein, a "control" is an alternative sample used in an
experiment for
comparison purpose. A control can be "positive" or "negative." For example,
where
the purpose of the experiment is to determine a correlation of the efficacy of
a
therapeutic agent for the treatment for a particular type of disease, a
positive control
(a compound or composition known to exhibit the desired therapeutic effect)
and a
negative control (a subject or a sample that does not receive the therapy or
receives a
placebo) are typically employed.
[0041] As used herein, the term "effective amount" refers to a quantity
sufficient to
achieve a desired therapeutic and/or prophylactic effect, e.g., an amount
which results
in the prevention of, or amelioration of a disease or medical condition
described
herein or one or more symptoms associated with a disease or medical condition
described herein. In the context of therapeutic or prophylactic applications,
the
amount of a composition administered to the subject will depend on the type
and
severity of the disease and on the characteristics of the individual, such as
general
health, age, sex, body weight and tolerance to drugs. It will also depend on
the
degree, severity and type of disease. The skilled artisan will be able to
determine
appropriate dosages depending on these and other factors. The compositions can
also
be administered in combination with one or more additional therapeutic
compounds.
In some embodiments, an effective amount of a compound is an amount of the
compound sufficient to modulate, normalize, or enhance one or more energy
biomarkers (where modulation, normalization, and enhancement are defined
herein).
In the methods described herein, the compositions of the present technology
may be
administered to a subject having one or more signs or symptoms of a disease or
medical condition described herein. For example, a "therapeutically effective
17
CA 02881746 2015-02-13
amount" of the mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) is
meant levels at which the physiological effects of a particular disease or
medical
condition are, at a minimum, ameliorated. A therapeutically effective amount
can be
given in one or more administrations. By way of example only, in some
embodiments, the disease or medical condition is a mitochondrial disease or
disorder.
In some embodiments, signs, symptoms or complications of a mitochondrial
disease
or disorder include, but are not limited to: poor growth, loss of muscle
coordination,
muscle weakness, neurological deficit, seizures, autism, autistic spectrum,
autistic-
like features, learning disabilities, heart disease, liver disease, kidney
disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection,
thyroid dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation, memory loss, failure to thrive, poor coordination, sensory
(vision,
hearing) problems, reduced mental functions, hypotonia, disease of the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle
spasms, tremors, chorea), stroke, brain atrophy, or any other sign or symptom
of a
mitochondrial disease state disclosed herein. In other embodiments of the
method, the
disease or medical condition is selected from the group consisting of
vitiligo,
porphyria, Alport Syndrome, and IPF.
[0042] As used herein, the terins "enhancement" of, or to "enhance," energy
biomarkers means to improve the level of one or more energy biomarkers in a
direction that results in a beneficial or desired physiological outcome in a
subject
(compared to the values observed in a normal control subject, or the value in
the
subject prior to treatment with a composition or compound). For example, in a
situation where significant energy demands are placed on a subject, it may be
desirable to increase the level of ATP in that subject to a level above the
ATP level
observed in a normal control subject. Enhancement can also be of beneficial
effect in
a subject suffering from a disease or pathology such as a mitochondrial
disease, in
that normalizing an energy biomarker may not achieve the optimum outcome for
the
subject; in such cases, enhancement of one or more energy biomarkers can be
beneficial, for example, higher-than-normal levels of ATP, or lower-than
normal
levels of lactic acid (lactate) can be beneficial to such a subject.
18
CA 02881746 2015-02-13
[0043] As used herein, "expression" refers to the process by which
polynucleotides
are transcribed into mRNA and/or the process by which the transcribed mRNA is
subsequently being translated into peptides, polypeptides, or proteins. If the
polynucleotide is derived from genomic DNA, expression may include splicing of
the
mRNA in an eukaryotic cell. The expression level of a gene may be determined
by
measuring the amount of mRNA or protein in a cell or tissue sample. In one
aspect,
the expression level of a gene from one sample may be directly compared to the
expression level of that gene from a control or reference sample. In another
aspect,
the expression level of a gene from one sample may be directly compared to the
expression level of that gene from the same sample following administration of
a
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*).
[0044] As used herein, the term "mitochondrial disease or disorder" refers to
any
disease or disorder that results from the perturbation of any
biological/physiological
process in the mitochondria. Non-limiting examples of mitochondrial disease
include
but are not limited to Alexander disease, Alpers Syndrome, Alpha-ketoglutarate
dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia with
spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia, GRACILE
Syndrome, Bjornstad Syndrome, Leigh Syndrome, mitochondrial complex III
deficiency nuclear type 1 (MC3DN1), combined oxidative phosphorylation
deficiency
18 (COXPD18), Thiamine-responsive megaloblastic anemia syndrome (TRMA),
Pearson Syndrome, HAM Syndrome, Ataxia, Cataract, and Diabetes Syndrome,
MELAS/MERRF Overlap Syndrome, combined oxidative phosphorylation
deficiency-14 (COXPD14), Infantile cerebellar-retinal degeneration (ICRD),
Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10 deficiency-1
(C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation (LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with
optic
atrophy (SPAX4), progressive external ophthalmoplegia with mitochondrial DNA
deletions autosomal dominant type 5 (PEOA5), mitochondrial complex III
deficiency
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CA 02881746 2015-02-13
nuclear type 2 (MC3DN2), episodic encephalopathy due to thiamine
pyrophosphokinase deficiency/Thiamine Metabolism Dysfunction Syndrome-5
(THMD5), Spinocerebellar ataxia-28 (SCA28), autosomal dominant cerebellar
ataxia,
deafness, and narcolepsy (ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar
ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss
(CAPOS)
Syndrome, spinocerebellar ataxia 7 (SCA7), Barth Syndrome, Biotinidase
deficiency,
gyrate atrophy, Syndromic Dominant Optic Atrophy and Deafness (Syndromic
DOAD), Dominant Optic Atrophy plus (D0Aplus), Leber's hereditary optic
neuropathy (LHON), Wolfram Syndrome-1 (WFS1), Wolfram Syndrome-2 (WFS2),
Age-related macular degeneration (ARMD), Brunner Syndrome, Left ventricular
noncompaction-1 (LVNC1), histiocytoid cardiomyopathy, Familial Myalgia
Syndrome, Parkinsonism, Fatal infantile cardioencephalomyopathy due to
cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP) deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency, cardiomyopathy + encephalomyopathy, mitochondrial phosphate
carrier
deficiency, infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency (CEMCOX2),(3-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency,
ECHS1) deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated
cardiomyopathy with ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12
(MTDPS12), cardiomyopathy due to mitochondrial tRNA deficiencies,
mitochondrial
complex V (ATP synthase) deficiency nuclear type 1 (MC5DN1), combined
oxidative
phosphorylation deficiency-8 (COXPD8), progressive leukoencephalopathy with
ovarian failure (LKENP), combined oxidative phosphorylation deficiency-10
(COXPD10), combined oxidative phosphorylation deficiency-16 (COXPD16),
combined oxidative phosphorylation deficiency-17 (COXPD17), combined oxidative
phosphorylation deficiency-5 (COXPD5), combined oxidative phosphorylation
deficiency-9 (COXPD9), carnitine acetyltransferase (CRAT) deficiency,
carnitine
palmitoyltransferase I (CPT I) deficiency, myopathic carnitine deficiency,
primary
systemic carnitine deficiency (CDSP), carnitine palmitoyltransferase II (CPT
II)
deficiency, carnitine-acylcarnitine translocase deficiency (CACTD), cartilage-
hair
hypoplasia, cerebrotendinous xanthomatosis (CTX), congenital adrenal
hyperplasia
(CAH), megaconial type congenital muscular dystrophy, cerebral creatine
deficiency
syndrome-3 (CCDS3), maternal nonsyndromic deafness, maternal nonsyndromic
CA 02881746 2015-02-13
deafness, autosomal dominant deafness-64 (DFNA64), Mohr-Tranebjaerg Syndrome,
Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency (DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1
(MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple
Mitochondrial Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy
associated with mitochondrial Complex II deficiency, encephalopathies
associated
with mitochondrial Complex I deficiency, encephalopathies associated with
mitochondrial Complex III deficiency, encephalopathies associated with
mitochondrial Complex IV deficiency, encephalopathies associated with
mitochondrial Complex V deficiency, hyperammonemia due to carbonic anhydrase
VA deficiency (CA5AD), early infantile epileptic encephalopathy-3 (EIEE3), 2,4-
Dienoyl-CoA reductase deficiency (DECRD), infection-induced acute
encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE), hypomyelinating
leukodystrophy (HLD4), exocrine pancreatic insufficiency, dyserythropoietic
anemia
and calvarial hyperostosis, Glutaric aciduria type 1 (GA-1), glycine
encephalopathy
(GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-hydroxyacyl-CoA
dehydrogenase deficiency, familial hyperinsulinemic hypoglycemia (FHH),
hypercalcemia infantile, hyperornithinemia-hyperammonemia-homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion
Body Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous myopathies with anti-mitochondrial antibodies, necrotizing
myopathy
with pipestem capillaries, myopathy with deficient chondroitin sulfate C in
skeletal
muscle connective tissue, benign acute childhood myositis, idiopathic orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated myositis, Facioscapulohumeral dystrophy (FSH), familial idiopathic
inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus, Addison disease,
Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS), focal myositis,
autoimmune fasciitis, Spanish toxic oil-associated fasciitis, Eosinophilic
fasciitis,
Macrophagic myofasciitis, Graft-vs-host disease fasciitis, Eosinophilia-
myalgia
Syndrome, perimyositis, isovaleric acidemia (IVA), Kearnes-Sayre Syndrome
(KSS),
2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle Muscular Dystrophy
Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-Methylcrotonyl-
CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller Syndrome,
21
CA 02881746 2015-02-13
Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular atrophy
syndrome, rigid spine syndrome, severe myopathy with motor regression,
Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia,
MNGIE, MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked
distal spinal muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF,
progressive external ophthalmoplegia with myoclonus, deafness and diabetes
(DD),
multiple symmetric lipomatosis, Myopathy with Episodic high Creatine Kinase
(MIMECK), Epilepsia Partialis Continua, malignant hyperthermia syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
medication-, drug- or toxin-induced myoglobinuria, mitochondrial disorder-
associated
myoglobinuria, hypokalemic myopathy and rhabdomyolysis, muscle trauma-
associated myoglobinuria, ischemia-induced myoglobinuria, infection-induced
myoglobinuria, immune myopathies associated with myoglobinuria, Myopathy,
lactic
acidosis, and sideroblastic anemia (MLASA), infantile mitochondrial myopathy
due
to reversible COX deficiency (MMIT), Myopathy, Exercise intolerance,
Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder, maternally-inherited mitochondrial myopathies, myopathy with lactic
acidosis, myopathy with rhabdomyolysis, Myopathy with cataract and combined
respiratory chain deficiency, myopathy with abnormal mitochondrial
translation,
Fatigue Syndrome, myopathy with extrapyramidal movement disorders (MPXPS),
glutaric aciduria II (MADD), primary C0Q10 deficiency-1 (C0Q10D1), primary
CoQ10 deficiency-2 (C0Q10D2), primary CoQ10 deficiency-3 (C0Q10D3), primary
CoQ10 deficiency-5 (C0Q10D5), secondary C0Q10 deficiency, autosomal dominant
mitochondrial myopathy, myopathy with focal depletion of mitochondria,
mitochondrial DNA breakage syndrome (PEO + Myopathy), lipid type mitochondrial
myopathy, multiple symmetric lipomatosis (MSL), N-acetylglutamate synthase
(NAGS) deficiency, Nephronophthisis (NPHP), ornithine transcarbamylase (OTC)
deficiency, neoplasms, NARP Syndrome, paroxysmal nonkinesigenic dyskinesia
(PNKD), sporadic PEO, maternally-inherited PEO, autosomal dominant progressive
external ophthalmoplegia with mitochondrial DNA deletions-3 (PEOA3), autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
2
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CA 02881746 2015-02-13
(PEOA2), autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO +
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal dominant progressive external ophthalmoplegia-6 (PEOA6), PEO +
Myopathy and Parkinsonism, autosomal recessive progressive external
ophthalmoplegia (PEOB), Mitochondrial DNA Depletion Syndrome-11 (MTDP S11),
PEO with cardiomyopathy, PEPCK deficiency, Perrault Syndromes (PRLTS),
propionic acidemia (PA), pyruvate carboxylase deficiency, pyruvate
dehydrogenase
El-alpha deficiency (PDHAD), pyruvate dehydrogenase El-beta deficiency
(PDHBD), dihydrolipoamide dehydrogenase (DLD) deficiency, pyruvate
dehydrogenase phosphatase deficiency, pyruvate dehydrogenase E3-binding
protein
deficiency (PDHXD), mitochondrial pyruvate carrier deficiency (MPYCD),
Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-chain acyl-
CoA
dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA transferase (SCOT)
deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC), Very
long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-dependent
rickets type 1 A (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues, germanium myopathy, Parkinsonism and mitochondrial Complex I
neurotoxicity due to trichloroethylene, valproate-induced hepatic failure,
neurodegeneration with brain iron accumulation-4 (NBIA4), Complex I
deficiency,
Complex II deficiency, Complex III deficiency, Complex IV deficiency, Complex
V
deficiency, Cytochrome c oxidase (COX) deficiency, combined complex I, II, IV,
V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3), combined oxidative phosphorylation deficiency-4 (COXPD4), combined
oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD 1 1), combined oxidative phosphorylation deficiency-12 (COXPD 12),
combined oxidative phosphorylation deficiency-13 (COXPD13), combined oxidative
phosphorylation deficiency-15 (COXPD15), combined oxidative phosphorylation
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CA 02881746 2015-02-13
deficiency-16 (COXPD16), combined oxidative phosphorylation deficiency-19
(COXPD19), combined oxidative phosphorylation deficiency-20 (COXPD20),
combined oxidative phosphorylation deficiency-21 (COXPD21), fumarase
deficiency,
HMG-CoA synthase-2 deficiency, hyperuricemia, pulmonary hypertension, renal
failure, and alkalosis (HUPRA) Syndrome, syndromic microphthalmia-7,
pontocerebellar hypoplasia type 6 (PCH6), Mitochondrial DNA Depletion Syndrome-
9 (MTDPS9P), and Sudden infant death Syndrome (SIDS).
[0045] As used herein, the terms "mitochondrial fission inhibitor peptide," or
"fission inhibitor peptide" are used interchangeably herein to refer to the
peptides
represented by SEQ ID NOS: 3-8 and 10-11, or derivatives, analogues, or
pharmaceutically acceptable salts thereof (e.g., P110*), which function to
inhibit
mitochondrial fission as well as to inhibit GTPase activation of the Drpl
protein. In
some embodiments, the mitochondrial fission inhibitor peptide is P110 and/or
P110*.
[0046] As used herein, "P110" refers to mitochondrial fission inhibitor
peptides of
at least 7 amino acids that are derived from region 110 of the GTPase domain
of the
Drpl protein. See Figures 2A-2C. In some embodiments, the P110 peptide has the
sequence DLLPRGT (SEQ ID NO:3), which corresponds to amino acids 49 through
55 of the human Drpl protein (SEQ ID NO:1), and is represented by the formula:
0 0
H H
N,..õ,...õ.õ....õ--..õ,.., ,......õ..-...õ,,,...m...õ,.,N,,,,...._õ7õ---
0 N N NH2
H
H
H2N,.........,.....,,,,,,,,,,,, ......,,,,,,,...õ.......õ,õN 0
N 0 .."...../......õõ,
H 0 OH
0.'' 0
NH
OH
HN
NH2
[0047] In other embodiments, the P110 amino acid sequence is DLLPRGS (SEQ ID
NO:10). In other embodiments, the P110 amino acid sequence is DFLPRGS (SEQ ID
NO:11). As used herein, the term "P110" is meant to include polypeptides
comprising SEQ ID NOS: 3, and 10-11 and pharmaceutically acceptable salts
thereof
[0048] As used herein, "P110*" collectively refers to derivatives, variants or
analogues of P110, such as but not limited to Formula I, stereoisomers
thereof,
tautomers thereof, solvates thereof, and pharmaceutically acceptable salts
thereof
24
CA 02881746 2015-02-13
[0049] As used herein, the "modulation" of, or to "modulate," an energy
biomarker
means to change the level of the energy biomarker towards a desired value, or
to
change the level of the energy biomarker in a desired direction (e.g.,
increase or
decrease). Modulation can include, but is not limited to, normalization and
enhancement as defined herein.
[0050] As used herein, the terms "normalization" of, or to "normalize," an
energy
biomarker is defined as changing the level of the energy biomarker from a
pathological value towards a normal value, where the normal value of the
energy
biomarker can be 1) the level of the energy biomarker in a healthy person or
subject,
or 2) a level of the energy biomarker that alleviates one or more undesirable
symptoms in the person or subject. That is, to normalize an energy biomarker
which
is depressed in a disease state means to increase the level of the energy
biomarker
towards the normal (healthy) value or towards a value which alleviates an
undesirable
symptom; to normalize an energy biomarker which is elevated in a disease state
means to decrease the level of the energy biomarker towards the normal
(healthy)
value or towards a value which alleviates an undesirable symptom.
[0051] The terms "nucleic acid molecule" and "polynucleotide" are used
interchangeably and refer to a polymeric form of nucleotides of any length,
either
deoxyribonucleotides or ribonucleotides, or analogues thereof. Non-limiting
examples of polynucleotides include linear and circular nucleic acids,
messenger
RNA (mRNA), cDNA, recombinant polynucleotides, vectors, probes, and primers.
[0052] As used herein, the terms "polypeptide," "peptide," and "protein" are
used
interchangeably herein to mean a polymer comprising two or more amino acids
joined
to each other by peptide bonds or modified peptide bonds, i.e., peptide
isosteres.
Polypeptide refers to both short chains, commonly referred to as peptides,
glycopeptides or oligomers, and to longer chains, generally referred to as
proteins.
Polypeptides may contain amino acids other than the 20 gene-encoded amino
acids.
Polypeptides include amino acid sequences modified either by natural
processes, such
as post-translational processing, or by chemical modification techniques that
are well
known in the art.
[0053] As used herein, "prevention" or "preventing" of a disease or medical
condition refers to a compound that, in a statistical sample, reduces the
occurrence of
CA 02881746 2015-02-13
the disease or medical condition in the treated sample relative to an
untreated control
sample, or delays the onset of one or more symptoms of the disease or medical
condition relative to the untreated control sample.
[0054] As used herein, the term "simultaneous" therapeutic use refers to the
administration of at least two active ingredients by the same route and at the
same
time or at substantially the same time.
[0055] As used herein, the term "separate" therapeutic use refers to an
administration of at least two active ingredients at the same time or at
substantially the
same time by different routes.
[0056] As used herein, the term "sequential" therapeutic use refers to
administration
of at least two active ingredients at different times, the administration
route being
identical or different. More particularly, sequential use refers to the whole
administration of one of the active ingredients before administration of the
other or
others commences. It is thus possible to administer one of the active
ingredients over
several minutes, hours, or days before administering the other active
ingredient or
ingredients. There is no simultaneous treatment in this case.
[0057] The term "similarity" with reference to amino acid sequences as used
herein
refers to amino acid sequences in which the amino acid at a specific position
is
identical or has been substituted with a different amino acid with
functionally
equivalent physicochemical characteristics.
[0058] The terms "subject," "individual," and "patient" are used
interchangeably
herein to refer to a member or members of any mammalian or non-mammalian
species that may have a need for the methods and compositions described
herein.
Subjects and patients thus include, without limitation, primate (including
humans and
non-human primates), canine, feline, ungulate (e.g., equine, bovine, swine
(e.g., pig)),
avian, and other subjects. In some cases, the subject is a murine (e.g., rat
or mouse),
such as a rat or mouse model of a disease. In some cases, the subject is a
human.
[0059] "Substantially pure" indicates that an entity (e.g., a mitochondrial
fission
inhibitor peptide) makes up greater than about 50% of the total content of the
composition (e.g., total protein of the composition), or greater than about
80% of the
total protein content. For example, a "substantially pure" composition refers
to
compositions in which at least 80%, at least 85%, at least 90% or more of the
total
26
CA 02881746 2015-02-13
composition is the entity of interest (e.g., 95%, 98%, 99%, greater than 99%),
of the
total protein. The protein can make up greater than about 90%, or greater than
about
95% of the total protein in the composition.
[0060] As used herein, a "synergistic therapeutic effect" refers to a greater-
than-
additive therapeutic effect which is produced by a combination of at least two
agents,
and which exceeds that which would otherwise result from the individual
administration of the agents. For example, lower doses of one or more agents
may be
used in treating a disease or disorder, resulting in increased therapeutic
efficacy and
decreased side-effects.
[0061] "Treating" or "treatment" as used herein covers the treatment of a
disease or
medical condition described herein, in a subject, such as a human, and
includes: (i)
inhibiting a disease or disorder, i.e., arresting its development; (ii)
relieving a disease
or disorder, i.e., causing regression of the disorder; (iii) slowing
progression of the
disorder; and/or (iv) inhibiting, relieving, or slowing progression of one or
more
symptoms of the disease or medical condition.
[0062] It is also to be appreciated that the various modes of treatment or
prevention
of medical diseases and conditions as described are intended to mean
"substantial,"
which includes total but also less than total treatment or prevention, and
wherein some
biologically or medically relevant result is achieved. The treatment may be a
continuous prolonged treatment for a chronic disease or a single, or few time
administrations for the treatment of an acute condition.
Mitochondrial Fission Inhibitor Peptides
[0063] Disclosed herein are mitochondrial fission inhibitor peptides that
impede
protein-protein interaction (PPI) between the fission protein, Drpl (Dynamin 1-
like
protein, GenBank Acc. No. AAH24590; SEQ ID NO:1) or an isoform thereof (e.g.,
GenBank Acc. No. 000429; SEQ ID NO:9), and its mitochondrial adaptor, Fisl
(mitochondrial fission 1 protein, GenBank Acc. No. NP_057152; SEQ ID NO:2) or
an isoform thereof Drpl is a large GTPase and its mitochondrial fission
activity is
dependent on its GTP hydrolysis. In some embodiments, a mitochondrial fission
inhibitor peptide of the present technology inhibits mitochondrial fission in
a cell
under pathological conditions, but does not inhibit mitochondrial fission in
normal
27
CA 02881746 2015-02-13
control cells. In certain embodiments, the mitochondrial fission inhibitor
peptides of
the present technology inhibit the GTPase activation of Drpl.
[0064] Figure 2A shows the 3 different regions of sequence similarity between
the
Drpl and Fisl proteins. The amino acid sequence for each of the 3 regions
within
each of the Drpl and Fisl proteins are presented in Figure 2B. While these
homologous sequences are conserved in a variety of species, only the sequence
in
region 110 (P110) is identical in mammals, fish, chicken and yeast, suggesting
its
importance in the function of Drpl (Figure 2C).
[0065] In some embodiments, a mitochondrial fission inhibitor peptide of the
present technology has a length of from about 7 amino acids to about 50 amino
acids,
e.g., from about 7 amino acids to about 10 amino acids, from about 10 amino
acids to
about 15 amino acids, from about 15 amino acids to about 20 amino acids, from
about
20 amino acids to about 25 amino acids, from about 25 amino acids to about 30
amino
acids, from about 30 amino acids to about 35 amino acids, from about 35 amino
acids
to about 40 amino acids, from about 40 amino acids to about 45 amino acids, or
from
about 45 amino acids to about 50 amino acids, or longer than 50 amino acids.
[0066] In some embodiments, a mitochondrial fission inhibitor peptide of the
present technology has a length of from about 7 amino acids to about 20 amino
acids,
e.g., 7 amino acids (aa), 8 aa, 9 aa, 10 aa, 11 aa, 12 aa, 13 aa, 14 aa, 15
aa, 16 aa, 17
aa, 18 aa, 19 aa, or 20 aa.
[0067] In some embodiments, a mitochondrial fission inhibitor peptide
comprises an
amino acid sequence having at least about 80%, at least about 85%, at least
about
90%, at least about 95%, at least about 98%, at least about 99%, or 100%,
amino acid
sequence identity to a contiguous stretch of from about 7 amino acids to about
20
amino acids of the Drp1 amino acid sequence (SEQ ID NO:1). A mitochondrial
fission inhibitor peptide can comprise an amino acid sequence differing in
amino acid
sequence by one, two, three, four, or five amino acids, compared to a
contiguous
stretch of from about 7 amino acids to about 20 amino acids of the Drpl amino
acid
sequence (SEQ ID NO:1). The amino acid differences can be conservative amino
acid differences.
[0068] In some embodiments, a mitochondrial fission inhibitor peptide
comprises an
amino acid sequence having at least about 80%, at least about 85%, at least
about
28
CA 02881746 2015-02-13
90%, at least about 95%, at least about 98%, at least about 99%, or 100%,
amino acid
sequence identity to a contiguous stretch of from about 7 amino acids to about
20
amino acids of the Fisl amino acid sequence (SEQ ID NO:2). A mitochondrial
fission inhibitor peptide can comprise an amino acid sequence differing in
amino acid
sequence by one, two, three, four, or five amino acids, compared to a
contiguous
stretch of from about 7 amino acids to about 20 amino acids of the Fisl amino
acid
sequence (SEQ ID NO:2). The amino acid differences can be conservative amino
acid differences.
[0069] "Conservative amino acid substitution" generally refers to substitution
of
amino acid residues within the following groups:
1) L, I, M, V, F;
2) R, K;
3) F, Y, H, W, R;
4) G, A, T, S;
5) Q, N; and
6) D, E.
[0070] Conservative amino acid substitutions in the context of a mitochondrial
fission inhibitor peptide are selected so as to preserve biological activity
of the
peptide. Biological activity may be preserved by replacing the side chain of
an amino
acid with a side chain of another amino acid having similar acidity, basicity,
charge,
polarity, or size. Guidance for substitutions, insertion, or deletion may be
based on
alignments of amino acid sequences of different variant proteins or proteins
from
different species. For example, at certain residue positions that are fully
conserved,
substitution, deletion or insertion may not be allowed while at other
positions where
one or more residues are not conserved, an amino acid change can be tolerated.
Residues that are semi-conserved may tolerate changes that preserve charge,
polarity,
and/or size. For example, a mitochondrial fission inhibitor peptide comprising
the
sequence DLLPRGS (SEQ ID NO:10) may have 1, 2 or 3 amino acid substitutions,
at
position 1, 2, 3, 4, 5, 6, and/or 7, wherein the substituted amino acid may be
any one
of the known 20 amino acids, wherein the fission inhibitor peptide maintains a
mitochondrial fission inhibiting function.
29
CA 02881746 2015-02-13
[0071] In one aspect, the present technology provides a mitochondrial fission
inhibitor peptide wherein the peptide comprises about 7 to 20 amino acids. In
one
embodiment, the peptide comprises an amino acid sequence having at least about
80%, 85%, 90%, or 95% amino acid identity to a contiguous stretch of from
about 7
to 20 amino acids of a Drpl polypeptide or a Fisl polypeptide.
[0072] In some embodiments, the Drpl polypeptide is about 80%, 85%, 90%, 95%,
98%, 99% or 100% identical to SEQ ID NO:l. A Drpl polypeptide can have at
least
about 80%, at least about 85%, at least about 90%, at least about 95%, at
least about
98%, at least about 99%, or 100%, amino acid sequence identity to a contiguous
stretch of from about 500 amino acids to about 600 amino acids, or from about
600
amino acids to about 650 amino acids, from about 650 amino acids to about 675
amino acids, or from about 675 amino acids to 710 amino acids, of the amino
acid
sequence depicted by SEQ ID NO:l.
[0073] In another embodiment, the Fisl polypeptide is about 80%, 85%, 90%,
95%,
98%, 99% or 100% identical to SEQ ID NO:2. A Fisl polypeptide can have at
least
about 80%, at least about 85%, at least about 90%, at least about 95%, at
least about
98%, at least about 99%, or 100%, amino acid sequence identity to a contiguous
stretch of from about 100 amino acids to about 120 amino acids, from about 120
amino acids to about 130 amino acids, from about 130 amino acids to about 140
amino acids, or from about 140 amino acids to 152 amino acids, of the amino
acid
sequence depicted by SEQ ID NO:2.
[0074] Non-limiting examples of mitochondrial fission inhibitor peptides
include
STQELLRFPK (SEQ ID NO:4); KLSAREQRD (SEQ ID NO:5); DLLPRGS (SEQ
ID NO:10); DLLPRGT (SEQ ID NO:3); SVEDLLKFEK (SEQ ID NO:7);
KGSKEEQRD (SEQ ID NO:8); ELLPKGS (SEQ ID NO:6), and DFLPRGS (SEQ ID
NO:11).
[0075] Each of these inhibitor peptides can be included in a mitochondrial
fission
inhibitor construct. A mitochondrial fission inhibiting peptide can comprise
an amino
acid sequence having at least about 80%, at least about 85%, at least about
90%, at
least about 95%, at least about 98%, at least about 99%, amino acid sequence
identity
to any of the above-listed amino acid sequences. A mitochondrial fission
inhibiting
peptide can comprise an amino acid sequence differing in amino acid sequence
by
CA 02881746 2015-02-13
one, two, three, four, or five amino acids, compared to any of the above-
listed amino
acid sequences.
[0076] Non-limiting examples of a mitochondrial fission inhibitor construct
include
the following: RRRQRRKKRGYGGSTQELLRFPK (SEQ ID NO:12);
RRRQRRKKRGYGGKLSAREQRD (SEQ ID NO:13);
RRRQRRKKRGYGGDLLPRGS (SEQ ID NO:14);
RRRQRRKKRGYGGDLLPRGT (SEQ ID NO:15);
RRRQRRKKRGYGGCSVEDLLKFEK (SEQ ID NO:16);
RRRQRRKKRGYGGKGSKEEQRD (SEQ ID NO:17); and
RRRQRRKKRGYGGELLPKGS (SEQ ID NO:18).
[0077] In some embodiments, the fission inhibitor construct comprises SEQ ID
NO:13, SEQ ID NO: 14; SEQ ID NO:15, or SEQ ID NO:17.
[0078] A mitochondrial fission inhibitor peptide can comprise an amino acid
sequence having at least about 80%, at least about 85%, at least about 90%, at
least
about 95%, at least about 98%, at least about 99%, amino acid sequence
identity to
any of the above-listed amino acid sequences. A mitochondria' fission
inhibitor
peptide can comprise an amino acid sequence differing in amino acid sequence
by
one, two, three, four, or five amino acids, compared to any of the above-
listed amino
acid sequences.
[0079] In one embodiment, the mitochondrial fission inhibitor peptide
comprises a
peptide that is about 43%, 57%, 71%, or 86% identical to the sequence DLLPRGS
(SEQ ID NO:10).
[0080] In another embodiment, the fission inhibitor peptide comprises a
peptide that
is about 89%, 78%, 67%, or 56% identical to the sequence KLSAREQRD (SEQ ID
NO:5).
[0081] In still another embodiment, the fission inhibitory peptide comprises a
peptide that is about 89%, 78%, 67%, or 56% identical to the sequence
KGSKEEQRD (SEQ ID NO:8).
[0082] In one embodiment, the mitochondria' fission inhibitor peptide
comprises a
peptide that is about 43%, 57%, 71%, or 86% identical to the sequence ELLPKGS
(SEQ ID NO:6).
31
CA 02881746 2015-02-13
[0083] In one embodiment, the fission inhibitor peptide comprises SEQ ID NOS:
5,
6, 8, or 10.
Constructs
[0084] Also provided herein are mitochondrial fission inhibitor constructs,
wherein
the construct comprises a mitochondrial fission inhibitor peptide.
[0085] In another aspect, the present disclosure provides mitochondrial
fission
inhibitor constructs comprising (a) a carrier peptide; (b) an optional linker;
and (c) a
mitochondrial fission inhibitor peptide. In some embodiments, the optional
linker is
from about 1 amino acid to about 40 amino acids. In some embodiments, the
inhibitor construct comprises, in order from amino terminus to carboxyl
terminus: a) a
protein transduction moiety, b) an optional linker, and c) a mitochondrial
fission
inhibitor peptide.
[0086] In some embodiments, a mitochondrial fission inhibitor construct
comprises
a carrier moiety (also referred to herein as a "protein transduction moiety"),
in
addition to a mitochondrial fission inhibitor peptide. "Carrier moiety" refers
to a
polypeptide, polynucleotide, carbohydrate, or organic or inorganic compound
that
facilitates traversing a lipid bilayer, micelle, cell membrane, organelle
membrane, or
vesicle membrane. A carrier moiety attached to another molecule facilitates
the
molecule traversing a membrane, for example going from extracellular space to
intracellular space, or cytosol to within an organelle. In some cases, a
carrier moiety
facilitates crossing the blood-brain barrier. In some embodiments, a carrier
moiety is
covalently linked to the amino terminus of a mitochondrial fission inhibiting
peptide.
In some embodiments, a carrier moiety is covalently linked to the carboxyl
terminus
of a mitochondrial fission inhibiting peptide.
[0087] In some embodiments, the carrier moiety is a carrier peptide. In some
embodiments, the carrier moiety is a carrier peptide and is covalently linked
to a
fission inhibiting peptide. In some embodiments, the covalent linkage is a
peptide
bond. For example, the carrier peptide can be a polypeptide having a length of
from
about 5 amino acids (aa) to about 50 aa, e.g., from about 5 aa to about 10 aa,
from
about 10 aa to about 15 aa, from about 15 aa to about 20 aa, from about 20 aa
to about
25 aa, from about 25 aa to about 30 aa, from about 30 aa to about 40 aa, or
from about
40 aa to about 50 aa.
32
CA 02881746 2015-02-13
[0088] Exemplary protein transduction domains (PTDs) which may be linked to
the
mitochondria fission inhibitor peptides of the present technology include, but
are not
limited to, a minimal undecapeptide protein transduction domain corresponding
to
residues 47-57 of human immunodeficiency virus-1 (HIV-1) TAT (GenBank Acc.
No. AEB53027; including YGRKKRRQRRR (SEQ ID NO:19) or RRRQRRKKRGY
(SEQ ID NO:20)), a polyarginine sequence comprising a number of arginines
sufficient to direct entry into a cell (e.g., 3, 4, 5, 6, 7, 8, 9, 10, or 10-
50 arginines); a
VP22 domain (Zender et al. (2002) Cancer Gene Ther. 9(6):489-96); a Drosophila
Antennapedia protein transduction domain (Noguchi et al. (2003) Diabetes
52(7):1732-1737); a truncated human calcitonin peptide (Trehin et al. (2004)
Pharm.
Research 21:1248-1256); polylysine (Wender et al. (2000) Proc. Natl. Acad.
Sci.
USA 97:13003-13008); RRQRRTSKLMKR (SEQ ID NO:21); Transportan
GWTLNSAGYLLGKINLKALAALAKKIL (SEQ ID NO:22);
KALAWEAKLAKALAKALAKHLAKALAKALKCEA (SEQ ID NO:23); and
RQIKIWFQNRRMKWKK (SEQ ID NO:24). Other exemplary PTDs which may be
linked to the mitochondria fission inhibitor peptides of the present
technology include,
but are not limited to, any of the following: YGRKKRRQRRR (SEQ ID NO:25);
RRRQRRKKRGY (SEQ ID NO:26); RKKRRQRRR (SEQ ID NO:27); an arginine
homopolymer ranging from 3 arginine residues to 50 arginine residues;
YGRKKRRQRRR (SEQ ID NO:28); RRRQRRKKRGY (SEQ ID NO:29);
RKKRRQRR (SEQ ID NO:30); YARAAARQARA (SEQ ID NO:31);
THRLPRRRRRR (SEQ ID NO:32); and GGRRARRRRRR (SEQ ID NO:33).
[0089] In certain embodiments, the carrier peptide comprises the sequence
RRRQRRKKRGY (SEQ ID NO:20).
[0090] Where a mitochondrial fission inhibitor construct includes a linker
which
joins or links a carrier moiety to a mitochondrial fission inhibitor peptide,
the linker
may be a peptide having any of a variety of amino acid sequences. A linker
which is
a spacer peptide, can be of a flexible nature, although other chemical
linkages are not
excluded. A linker peptide can have a length of from about 1 amino acid to
about 40
amino acids, e.g., from about 1 amino acid (aa) to about 5 aa, from about 5 aa
to about
aa, from about 10 aa to about 20 aa, from about 20 aa to about 30 aa, or from
about
30 aa to about 40, in length. These linkers can be produced using synthetic,
linker-
encoding oligonucleotides to couple the proteins. Peptide linkers with a
degree of
33
CA 02881746 2015-02-13
flexibility can be used. The linking peptides may have virtually any amino
acid
sequence. In some embodiments, the linker peptide will have a sequence that
results
in a generally flexible peptide. For example, small amino acids such as
glycine and
alanine, are useful in creating a flexible peptide. The creation of such
linker
sequences is routine to those skilled in the art. Various linkers are
commercially
available and are considered suitable for use.
[0091] Linkers can be readily selected and can have different lengths, e.g.,
from 1
amino acid (e.g., Gly) to 40 amino acids, from 2 amino acids to 15 amino
acids, from
3 amino acids to 12 amino acids, including 4 amino acids to 10 amino acids, 5
amino
acids to 9 amino acids, 6 amino acids to 8 amino acids, or 7 amino acids to 8
amino
acids, and may be 1, 2, 3, 4, 5, 6, or 7 amino acids.
[0092] Exemplary flexible linkers which can be used to join or link a carrier
moiety
to a mitochondrial fission inhibitor peptide, for example, via peptide bonds,
include
glycine polymers (G)n, (e.g., where n is an integer from 1 to about 20);
glycine-serine
polymers (including, for example, (GS)n, GSGGSn (SEQ ID NO:34) and GGGSn
(SEQ ID NO:35), where n is an integer of at least one), glycine-alanine
polymers,
alanine-serine polymers, and other flexible linkers known in the art. Glycine
and
glycine-serine polymers are especially useful since both of these amino acids
are
relatively unstructured, and therefore may serve as a neutral tether between
components. In some embodiments, glycine polymers are used. See Scheraga, Rev.
Computational Chem. 11173-142 (1992). Exemplary flexible linkers include, but
are
not limited to GG, GGG, GGS, GGSG (SEQ ID NO:36), GGSGG (SEQ ID NO:37),
GSGSG (SEQ ID NO:38), GSGGG (SEQ ID NO:39), GGGSG (SEQ ID NO:40),
GSSSG (SEQ ID NO:41), GGGG (SEQ ID NO:42) and the like.
[0093] Non-peptide linker moieties can also be used to join or link a carrier
moiety
to a mitochondrial fission inhibitor peptide. The linker molecules are
generally about
6-50 atoms long. The linker molecules may also be, for example, aryl
acetylene,
ethylene glycol oligomers containing 2-10 monomer units, diamines, diacids,
amino
acids, or combinations thereof Other linker molecules which can bind to
polypeptides may be used in light of this disclosure.
[0094] In some embodiments, the mitochondrial fission inhibitor construct is a
linear peptide which comprises the carrier peptide linked to the mitochondrial
fission
34
CA 02881746 2015-02-13
inhibitor peptide by a peptide bond. In certain embodiments, the fission
inhibitor
construct further comprises a linker, wherein the linker is positioned between
the
fission inhibitor peptide and the carrier peptide and the linker is linked at
one end to
the fission inhibitor peptide by a peptide bond and is linked at the other end
to the
carrier peptide by a peptide bond. In some embodiments, the linker comprises
1, 2, 3,
4, 5, or more amino acids. In another embodiment, the linker comprises 1 to 2,
1 to 5,
2 to 5, 2 to 4, 1 to 10, 5 to 10, 3 to 6, or 2 to 10 amino acids. In some
embodiments,
the linker is G, GG, GGG, or GGGG (SEQ ID NO:42).
[0095] In an alternative embodiment, the fission inhibitor peptide may be
linked to
the carrier peptide by a disulfide bond. In some embodiments, the disulfide
bond is
formed between two cysteines, two cysteine analogues or a cysteine and a
cysteine
analogue. In this embodiment, both the modulatory peptide and the carrier
peptide
contain at least one cysteine or cysteine analogue. The cysteine residue or
analogue
may be present as the N-terminal or C-terminal residue of the peptide or as an
internal
residue of the fission inhibitor peptide and of the carrier peptide. The
disulfide
linkage is then formed between the sulfur residues on each of the cysteine
residues or
analogues. Thus, the disulfide linkage may form between, for example, the N-
terminus of the fission inhibitor peptide and the N-terminus of the carrier
peptide, the
C-terminus of the fission inhibitor peptide and the C-terminus of the carrier
peptide,
the N-terminus of the fission inhibitor peptide and the C-terminus of the
carrier
peptide, the C-terminus of the fission inhibitor peptide and the N-terminus of
the
carrier peptide, or any other such combination including at any internal
position
within the fission inhibitor peptide and/or the carrier peptide.
[0096] In some embodiments, the fission inhibitor peptides and constructs of
the
present technology inhibit Drpl GTPase activity. In another embodiment, the
fission
inhibitor peptides and constructs of the present technology have no effect on
the
GTPase activity of a polypeptide that has GTPase activity, other than a Drpl
polypeptide. Thus, a mitochondrial fission inhibitor construct or peptide can
in some
cases selectively inhibit GTPase activity of a Drpl polypeptide. For example,
a
mitochondrial fission inhibitor construct or peptide has no substantial effect
on the
GTPase activity of mitofusin-1, Dynamin 1 or OPAL Mitofusin-1 polypeptides are
known in the art. See, e.g., Santel et al. (2003) J. Cell Sci, 116:2763;
Santel and
Fuller (2001)J. Cell Sci. 114:867; Hales and Fuller (1997) Cell 90:121; and
GenBank
CA 02881746 2015-02-13
Accession No. NP 284941. OPA1 polypeptides are known in the art. See, e.g.,
Alexander et al. (2000) Nat. Genet. 26:211; Dadgar et al. (2006) Exp. Eye Res.
83:702; and GenBank Accession No. NP 056375.
[0097] In some embodiments, a mitochondrial fission inhibitor construct
comprises
a mitochondrial fission inhibitor peptide which has a sequence which is about
42%,
57%, 71%, or 86% identical to the sequence DLLPRGS (SEQ ID NO:10) (e.g.,
contains 1, 2, 3, or 4 conservative amino acid substitutions such as Ser to
Thr; e.g.,
DLLPRGT (SEQ ID NO:3)), and in which the inhibitor construct or peptide
selectively inhibits Drpl GTPase activity.
[0098] In other embodiments, the inhibitor construct comprises a sequence
which is
about 56%, 67%, 78%, or 89% identical to the sequence DLLPRGT (SEQ ID NO:3)
or ELLPKGS (SEQ ID NO:6) (contains 1, 2, 3, or 4 conservative amino acid
substitutions), and in which the inhibitor construct or peptide inhibits Drpl
GTPase
activity.
[0099] In some embodiments, a mitochondrial fission inhibitor construct or
peptide
of the present technology can inhibit GTPase activity of a Drpl polypeptide by
at
least about 10%, at least about 15%, at least about 20%, at least about 25%,
at least
about 30%, at least about 35%, at least about 40%, at least about 50%, at
least about
60%, at least about 70%, at least about 80%, or more than 80%, compared to the
level
of GTPase activity of the Drpl polypeptide in the absence of the mitochondrial
fission
inhibitor construct or peptide.
[0100] In some embodiments, the fission inhibitor peptides and constructs as
described herein inhibit intermolecular interactions between a Drpl
polypeptide and a
Fisl polypeptide. Activation of mitochondrial fission by Drpl involves the
interaction of Drpl with Fisl which is located in the outer membrane of the
mitochondria. In some embodiments, the fission inhibitor peptides and
constructs
selectively inhibit binding of a Fisl polypeptide to a Drpl polypeptide.
[0101] In some embodiments, a mitochondrial fission inhibitor construct or
peptide
of the present technology can inhibit binding of a Drpl polypeptide to an Fisl
polypeptide by at least about 10%, at least about 15%, at least about 20%, at
least
about 25%, at least about 30%, at least about 35%, at least about 40%, at
least about
50%, at least about 60%, at least about 70%, at least about 80%, or more than
80%,
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CA 02881746 2015-02-13
compared to the degree of binding of the Drpl polypeptide to the Fisl
polypeptide in
the absence of the mitochondrial fission inhibitor construct or peptide.
[0102] In some embodiments, a mitochondrial fission inhibitor construct or
peptide
of the present technology can interfere with intramolecular interactions or
intermolecular interactions between Drpl oligomers by at least about 10%, at
least
about 15%, at least about 20%, at least about 25%, at least about 30%, at
least about
35%, at least about 40%, at least about 50%, at least about 60%, at least
about 70%, at
least about 80%, or more than 80%, compared to the degree of intramolecular
interactions or intermolecular interactions between Drpl oligomers in the
absence of
the mitochondrial fission inhibitor construct or peptide.
[0103] In some embodiments, a mitochondrial fission inhibitor peptide or
construct
can reduce mitochondrial fragmentation in a cell under pathological conditions
(e.g.,
where mitochondria in the cell are undergoing pathological mitochondrial
fission).
For example, a mitochondrial fission inhibitor peptide or construct of the
present
technology can reduce mitochondrial fragmentation in a cell by at least about
10%, at
least about 15%, at least about 20%, at least about 25%, at least about 30%,
at least
about 35%, at least about 40%, at least about 50%, at least about 60%, at
least about
70%, at least about 80%, or more than 80%, compared to the degree of
mitochondrial
fragmentation in the absence of the mitochondrial fission inhibitor construct
or
peptide.
[0104] In some embodiments, a mitochondrial fission inhibitor peptide or
construct
of the present technology can inhibit translocation of a Drpl polypeptide from
the
cytosol to mitochondria in a cell. For example, a mitochondrial fission
inhibitor
peptide or construct can inhibit translocation of a Drpl polypeptide from the
cytosol
to mitochondria in a cell by at least about 10%, at least about 15%, at least
about 20%,
at least about 25%, at least about 30%, at least about 35%, at least about
40%, at least
about 50%, at least about 60%, at least about 70%, at least about 80%, or more
than
80%, compared to the degree of translocation of the Drpl polypeptide from the
cytosol to mitochondria in the absence of the mitochondrial fission inhibitor
peptide
or construct. Methods for synthesizing the mitochondrial fission inhibitor
peptides of
the present technology are described in Qi et al., J Cell Sci. 126(3):789-802
(2013)
and U.S. Patent No. 8,748,393.
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Modification of Mitochondrial Fission Inhibitor Peptides and Constructs
[0105] In some embodiments, a fission inhibitor peptide comprises one or more
modifications. For example, a mitochondrial fission inhibitor construct or
peptide can
be cyclized. As another example, a fission inhibitor peptide can have one or
more
amino acid modifications. A mitochondrial fission inhibitor construct or
peptide of
the present technology can include one or more D-amino acids. In some
embodiments, the fission inhibitor peptide, the carrier peptide, and/or the
linker
comprises one or more D-amino acids.
[0106] Modifications of interest that do not alter primary sequence include
chemical
derivatization of polypeptides, e.g., acetylation, or carboxylation. Also
included are
modifications of glycosylation, e.g., those made by modifying the
glycosylation
patterns of a polypeptide during its synthesis and processing or in further
processing
steps; e.g., by exposing the polypeptide to enzymes which affect
glycosylation, such
as mammalian glycosylating or deglycosylating enzymes. Also included are
peptides
that have phosphorylated amino acid residues, e.g., phosphotyrosine,
phosphoserine,
or phosphothreonine.
[0107] The present disclosure also provides mitochondrial fission inhibitor
constructs or peptides that have been modified using ordinary molecular
biological
techniques and synthetic chemistry so as to improve their resistance to
proteolytic
degradation or to optimize solubility properties or to render them more
suitable as a
therapeutic agent. Analogues of such peptides include those containing
residues other
than naturally occurring L-amino acids, e.g., D-amino acids or non-naturally
occurring synthetic amino acids.
[0108] A mitochondrial fission inhibitor construct or peptide of the present
technology may be joined to a wide variety of other oligopeptides or proteins
for a
variety of purposes. By providing for expression of the fission inhibitor
peptides of
the present technology, various post-translational modifications may be
achieved. For
example, by employing the appropriate coding sequences, one may provide
farnesylation or prenylation. For example, a mitochondrial fission inhibitor
construct
or peptide can be bound to a lipid group at a terminus, so as to be able to be
bound to
a lipid membrane, such as a lipo some.
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CA 02881746 2015-02-13
[0109] Other suitable modifications include, but are not limited to (1) end-
cappings
of the terminal of the fission inhibitor peptides, such as amidation of the C-
terminus
and/or acetylation or deamination of the N-terminus; (2) introducing
peptidomimetic
elements in the structure; and (3) cyclization, in which the cyclization of
the fission
inhibitor peptide can occur through natural amino acids or non-naturally-
occurring
building blocks.
[0110] In some embodiments, the amino terminus, the carboxyl terminus or both
the
amino and carboxyl termini of the mitochondrial fission construct are
modified. In
certain embodiments, the amino terminal modification is an amine group or an
acetyl
group. In some embodiments, the carboxyl terminal modification is an amide
group.
[0111] A mitochondrial fission inhibitor construct or peptide of the present
technology can include naturally-occurring and non-naturally occurring amino
acids.
In certain embodiments, a mitochondrial fission inhibitor construct or peptide
comprises D-amino acids, a combination of D- and L-amino acids, and/or various
"designer" amino acids (e.g., 13-methyl amino acids, Ca-methyl amino acids,
and Na-
methyl amino acids, etc.) to convey special properties to peptides.
[0112] Additionally, a mitochondrial fission inhibitor construct or peptide of
the
present technology can be a cyclic peptide. A mitochondrial fission inhibitor
construct or peptide of the present technology can include non-classical amino
acids
in order to introduce particular conformational motifs. Any known non-
classical
amino acid can be used. Non-classical amino acids include, but are not limited
to,
1,2,3,4-tetrahydroisoquinoline-3-carboxylate; (2S,3S)-methylphenylalanine,
(2S,3R)-
methyl-phenylalanine, (2R,3S)-methyl-phenylalanine and (2R,3R)-
methylphenylalanine; 2-aminotetrahydronaphthalene-2-carboxylic acid; hydroxy-
1,2,3,4-tetrahydroisoquinoline-3-carboxylate; 3-carboline (D and L); HIC
(histidine
isoquinoline carboxylic acid); and HIC (histidine cyclic urea). Amino acid
analogues
and peptidomimetics can be incorporated into a mitochondrial fission inhibitor
construct or peptide of the present technology to induce or favor specific
secondary
structures, including, but not limited to, LL-Acp (LL-3-amino-2-propenidone-6-
carboxylic acid), a 0-turn inducing dipeptide analogue; 13-sheet inducing
analogues; 13-
turn inducing analogues; a-helix inducing analogues; -y-turn inducing
analogues; Gly-
Ala turn analogue; amide bond isostere; tretrazol; and the like.
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CA 02881746 2015-02-13
[0113] A mitochondrial fission inhibitor construct or peptide of the present
technology can be a depsipeptide, e.g., a linear or a cyclic depsipeptide.
Kuisle et al.
(1999) Tet. Letters 40:1203-1206. "Depsipeptides" are compounds containing a
sequence of at least two alpha-amino acids and at least one alpha-hydroxy
carboxylic
acid, which are bound through at least one normal peptide link and ester
links, derived
from the hydroxy carboxylic acids, where "linear depsipeptides" may comprise
rings
formed through S¨S bridges, or through an hydroxy or a mercapto group of a
hydroxy- or mercapto-amino acid and the carboxyl group of another amino- or
hydroxy-acid but do not comprise rings formed only through peptide or ester
links
derived from hydroxy carboxylic acids. "Cyclic depsipeptides" are peptides
containing at least one ring formed only through peptide or ester links,
derived from
hydroxy carboxylic acids.
[0114] A mitochondrial fission inhibitor construct or peptide of the present
technology can be cyclic or bicyclic. For example, the C-terminal carboxyl
group or a
C-terminal ester can be induced to cyclize by internal displacement of the ¨OH
or
the ester (¨OR) of the carboxyl group or ester respectively with the N-
terminal
amino group to form a cyclic peptide. For example, after synthesis and
cleavage to
give the peptide acid, the free acid is converted to an activated ester by an
appropriate
carboxyl group activator such as dicyclohexylcarbodiimide (DCC) in solution,
for
example, in methylene chloride (CH2C12), dimethyl formamide (DMF) mixtures.
The
cyclic peptide is then formed by internal displacement of the activated ester
with the
N-terminal amine. Internal cyclization as opposed to polymerization can be
enhanced
by use of very dilute solutions. Methods for making cyclic peptides are well
known
in the art. See, e.g., U.S. Patent Publication No. 2011/0092384.
[0115] The term "bicyclic" refers to a peptide comprising two ring closures.
The
ring closures are formed by covalent linkages between amino acids in the
peptide. A
covalent linkage between two nonadjacent amino acids constitutes a ring
closure, as
does a second covalent linkage between a pair of adjacent amino acids which
are
already linked by a covalent peptide linkage. The covalent linkages forming
the ring
closures may be amide linkages, i.e., the linkage formed between a free amino
on one
amino acid and a free carboxyl of a second amino acid, or linkages formed
between
the side chains or "R" groups of amino acids in the peptides. Thus, bicyclic
peptides
may be "true" bicyclic peptides, i.e., peptides cyclized by the formation of a
peptide
CA 02881746 2015-02-13
bond between the N-terminus and the C-terminus of the peptide, or they may be
"depsi-bicyclic" peptides, i.e., peptides in which the terminal amino acids
are
covalently linked through their side chain moieties.
[0116] A desamino or descarboxy residue can be incorporated at a terminus or
terminii of the fission inhibitor peptide, so that there is no terminal amino
or carboxyl
group, to decrease susceptibility to proteases or to restrict the conformation
of the
peptide. C-terminal functional groups include amide, amide lower alkyl, amide
di(lower alkyl), lower alkoxy, hydroxy, and carboxy, and the lower ester
derivatives
thereof, and the pharmaceutically acceptable salts thereof.
[0117] In some embodiments, a mitochondrial fission inhibitor construct or
peptide
of the present technology comprises one or more non-naturally occurring amino
acids
(e.g., non-encoded amino acids). In some embodiments, the non-naturally
encoded
amino acid comprises a carbonyl group, an acetyl group, an aminooxy group, a
hydrazine group, a hydrazide group, a semicarbazide group, an azide group, or
an
alkyne group. See, e.g.,U U.S. Pat. No. 7,632,924 for suitable non-naturally
occurring
amino acids.
[0118] Inclusion of a non-naturally occurring amino acid can provide for
linkage to
a polymer, a second polypeptide, a scaffold, etc. For example, a mitochondrial
fission
inhibitor construct or peptide of the present technology linked to a water-
soluble
polymer can be made by reacting a water-soluble polymer (e.g., poly(ethylene
glycol)
(PEG)) that comprises a carbonyl group to the mitochondrial fission inhibitor
construct or peptide that comprises a non-naturally encoded amino acid that
comprises an aminooxy, hydrazine, hydrazide or semicarbazide group.
[0119] As another example, a mitochondrial fission inhibitor construct or
peptide of
the present technology linked to a water-soluble polymer can be made by
reacting a
mitochondrial fission inhibitor construct or peptide that comprises an alkyne-
containing amino acid with a water-soluble polymer (e.g., PEG) that comprises
an
azide moiety; in some embodiments, the azide or alkyne group is linked to the
PEG
molecule through an amide linkage. A "non-naturally encoded amino acid" refers
to
an amino acid that is not one of the 20 common amino acids, pyrolysine or
selenocysteine. Other terms that may be used synonymously with the term "non-
naturally encoded amino acid" are "non-natural amino acid," "unnatural amino
acid,"
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CA 02881746 2015-02-13
"non-naturally-occurring amino acid," and variously hyphenated and non-
hyphenated
versions thereof The term "non-naturally encoded amino acid" also includes,
but is
not limited to, amino acids that occur by modification (e.g., post-
translational
modifications) of a naturally encoded amino acid (including but not limited
to, the 20
common amino acids, pyrolysine and selenocysteine) but are not themselves
naturally
incorporated into a growing polypeptide chain by the translation complex.
Examples
of such non-naturally-occurring amino acids include, but are not limited to, N-
acetylglucosaminyl-L-serine, N-acetylglucosaminyl-L-threonine, and 0-
phosphotyrosine.
[0120] In some embodiments, a mitochondrial fission inhibitor construct or
peptide
of the present technology is linked (e.g., covalently linked) to a polymer
(e.g., a
polymer other than a polypeptide). Suitable polymers include biocompatible
polymers, water-soluble biocompatible polymers, synthetic polymers and
naturally-
occurring polymers. In some embodiments, the polymers are substituted or
unsubstituted straight or branched chain polyalkylene, polyalkenylene or
polyoxyalkylene polymers or branched or unbranched polysaccharides, e.g., a
homo-
or hetero-polysaccharide. In some embodiments, the polymers are selected from
the
group consisting of ethylene vinyl alcohol copolymer (commonly known by the
generic name EVOH or by the trade name EVAL); polybutylmethacrylate;
poly(hydroxyvalerate); poly(L-lactic acid); polycaprolactone; poly(lactide-co-
glycolide); poly(hydroxybutyrate); poly(hydroxybutyrate-co-valerate);
polydioxanone; polyorthoester; polyanhydride; poly(glycolic acid); poly(D,L-
lactic
acid); poly(glycolic acid-co-trimethylene carbonate); polyphosphoester;
polyphosphoester urethane; poly(amino acids); cyanoacrylates;
poly(trimethylene
carbonate); poly(iminocarbonate); copoly(ether-esters) (e.g., poly(ethylene
oxide)-
poly(lactic acid) (PEO/PLA) co-polymers); polyalkylene oxalates;
polyphosphazenes;
biomolecules, such as fibrin, fibrinogen, cellulose, starch, collagen and
hyaluronic
acid; polyurethanes; silicones; polyesters; polyolefins; polyisobutylene and
ethylene-
alphaolefin copolymers; acrylic polymers and copolymers; vinyl halide polymers
and
copolymers, such as polyvinyl chloride; polyvinyl ethers, such as polyvinyl
methyl
ether; polyvinylidene halides, such as polyvinylidene fluoride and
polyvinylidene
chloride; polyacrylonitrile; polyvinyl ketones; polyvinyl aromatics, such as
polystyrene; polyvinyl esters, such as polyvinyl acetate; copolymers of vinyl
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monomers with each other and olefins, such as ethylene-methyl methacrylate
copolymers, acrylonitrile-styrene copolymers, ABS resins, and ethylene-vinyl
acetate
copolymers; polyamides, such as Nylon 66 and polycaprolactam; alkyd resins;
polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxy resins;
polyurethanes; rayon; rayon-triacetate; cellulose; cellulose acetate;
cellulose butyrate;
cellulose acetate butyrate; cellophane; cellulose nitrate; cellulose
propionate; cellulose
ethers; amorphous Teflon; poly(ethylene glycol); and carboxymethyl cellulose.
[0121] Suitable synthetic polymers include unsubstituted and substituted
straight or
branched chain poly(ethyleneglycol), poly(propyleneglycol) poly(vinylalcohol),
and
derivatives thereof, e.g., substituted poly(ethyleneglycol) such as
methoxypoly(ethyleneglycol), and derivatives thereof Suitable naturally-
occurring
polymers include, e.g., albumin, amylose, dextran, glycogen, and derivatives
thereof.
[0122] Suitable polymers can have an average molecular weight in a range of
from
500 Da to 50,000 Da, e.g., from 5000 Da to 40,000 Da, or from 25,000 to 40,000
Da.
For example, in some embodiments, where a mitochondrial fission inhibitor
construct
or peptide of the present technology comprises a poly(ethylene glycol) (PEG)
or
methoxypoly(ethyleneglycol) polymer, the PEG or methoxypoly(ethyleneglycol)
polymer can have a molecular weight in a range of from about 0.5 kiloDaltons
(kDa)
to 1 kDa, from about 1 kDa to 5 kDa, from 5 kDa to 10 kDa, from 10 kDa to 25
kDa,
from 25 kDa to 40 kDa, or from 40 kDa to 60 kDa. A mitochondrial fission
inhibitor
peptide or construct as described herein may be in the form of a
pharmaceutically
acceptable salt, including but not limited to, acid addition salts, such as
hydrochloride,
hydrobromide, sulfurate, nitrate, phosphorate, acetate, propionate, glycolate,
pyruvate,
oxalate, malate, malonate, succinate, maleate, fumarate, tartarate, citrate,
benzoate,
cinnamate, mandelate, methanesulfonate, ethanesulfonate, p-toluene-sulfonate,
salicylate and the like, and base addition salts, such as sodium, potassium,
calcium,
magnesium, lithium, aluminum, zinc, ammonium, ethylenediamine, arginine,
piperazine and the like.
[0123] Thus, in one aspect, the present technology provides a mitochondrial
fission
inhibitor construct comprising a mitochondrial fission inhibitor peptide
comprising
about 7 to 20 amino acids, wherein the peptide comprises an amino acid
sequence
having at least about 80% amino acid identity to a contiguous stretch of from
about 7
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CA 02881746 2015-02-13
to 20 amino acids of a Drp 1 polypeptide (SEQ ID NO:1) or a Fisl polypeptide
(SEQ
ID NO:2).
[0124] In some embodiments, the inhibitor construct further comprises a
protein
transduction moiety. In certain embodiments of the inhibitor construct, the
protein
transduction moiety is a carrier peptide. In some embodiments of the inhibitor
construct, the protein transduction moiety comprises a carrier peptide derived
from a
human immunodeficiency virus Tat polypeptide. In some embodiments of the
inhibitor construct, the protein transduction moiety comprises the sequence
RRRQRRKKRGY (SEQ ID NO:20).
[0125] In some embodiments of the inhibitor construct, the construct is a
linear
peptide comprising: a) the fission inhibitor peptide; b) an optional linker;
and c) a
carrier peptide. In certain embodiments, the linker is positioned between the
fission
inhibitor peptide and the carrier peptide.
[0126] Additionally or alternatively, in some embodiments of the inhibitor
construct, the fission inhibitor peptide comprises the sequence DLLPRGS (SEQ
ID
NO:10). In some embodiments, the inhibitor construct comprises the sequence
RRRQRRKKRGYGGDLLPRGS (SEQ ID NO:14).
[0127] Additionally or alternatively, in some embodiments, the inhibitor
construct
selectively inhibits the GTPase activity of a Drpl polypeptide. In some
embodiments,
the inhibitor construct inhibits binding of a Drpl polypeptide to a Fisl
polypeptide.
P110, Variants, Derivatives, and Analogues Thereof
[0128] In some embodiments, the P110 and/or P110* peptides of the present
technology are water-soluble and polar. In other embodiments, the P110 and/or
P110* peptides are less polar. In some embodiments, the P110 and/or P110*
peptides
can readily penetrate cell membranes. In other embodiments, the P110 and/or
P110*
peptides of the present technology are conjugated to a cell penetrating
peptide (CPP)
to increase cellular uptake of the P110 and/or P110* peptides. In some
embodiments,
a spacer of two or more amino acids is present between the CPP and the P110
and/or
P110* peptides. In one embodiment, the CPP is a TAT protein-derived peptide.
[0129] The P110* peptides of the present technology may be from about 7 to
about
100 amino acids, about 7 to about 60 amino acids, about 7 to about 50 amino
acids,
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CA 02881746 2015-02-13
about 7 to about 40 amino acids, about 7 to about 30 amino acids, about 7 to
about 20
amino acids, or about 7 to about 10 amino acids in length. In some
embodiments, the
P110* peptides comprise seven, eight, nine, or ten amino acids covalently
joined by
peptide bonds.
[0130] In some embodiments, the P110 and/or the P110* peptide comprises one or
more of the following characteristics. In some embodiments, the peptide
comprises at
least three amino acids that are identical to amino acid residues within
region 110 of
the GTPase domain of the human Drpl gene. In some embodiments, the peptides
comprise of at least three amino acids that are identical to amino acid
residues within
region 110 of the GTPase domain of the mouse Drpl gene. In some embodiments,
the peptides comprise of at least three amino acids that are identical to
amino acid
residues within region 110 of the GTPase domain of the rat Drpl gene. In some
embodiments, the peptides comprise of at least three amino acids that are
identical to
amino acid residues within region 110 of the GTPase domain of the chicken Drpl
gene. In some embodiments, the peptides comprise of at least three amino acids
that
are identical to amino acid residues within region 110 of the GTPase domain of
the
zebrafish Drpl gene.
[0131] In some embodiments, the P110 and/or the P110* peptide comprises one or
more of the following characteristics. In some embodiments, the peptides
comprise
amino acid residues 40-69 of human Drpl. In other embodiments, the peptides
comprise amino acid residues 49-55 of human Drpl. In some embodiments, the
peptides comprise amino acid residues 40-69 of mouse Drpl. In other
embodiments,
the peptides comprise amino acid residues 49-55 of mouse Drpl. In some
embodiments, the peptides comprise amino acid residues 40-69 of rat Drpl. In
other
embodiments, the peptides comprise amino acid residues 49-55 of rat Drpl. In
some
embodiments, the peptides comprise amino acid residues 47-76 of chicken Drpl.
In
other embodiments, the peptides comprise amino acid residues 56-62 of chicken
Drpl. In some embodiments, the peptides comprise amino acid residues 47-76 of
zebrafish Drpl. In other embodiments, the peptides comprise amino acid
residues 56-
62 of zebrafish Drpl.
[0132] In some embodiments, the P110 and/or P110* peptides of the present
technology comprise a sequence (about 7 to about 100 amino acids, about 7 to
about
60 amino acids, about 7 to about 50 amino acids, about 7 to about 40 amino
acids,
CA 02881746 2015-02-13
about 7 to about 30 amino acids, about 7 to about 20 amino acids, or about 7
to about
amino acids in length) that is at least 50%, at least 55%, at least 60%, at
least 65%,
at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least
95%, at
least 98%, or at least 100% identical to a sequence in region 110 of the Drpl
GTPase
domain in a vertebrate subject. In some embodiments, the vertebrate subject is
selected from the group consisting of human, mouse, rat, chicken, and
zebrafish. In
some embodiments, the sequence of the P110 and/or P110* peptide is at least
50%, at
least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least
80%, at least
85%, at least 90%, at least 95%, at least 98%, or at least 100% identical to a
sequence
in region 110 of the Drpl GTPase domain in a vertebrate subject. In some
embodiments, the vertebrate subject is selected from the group consisting of
human,
mouse, rat, chicken, and zebrafish. In some embodiments, the amino acid
sequence of
the P110 and/or P110* peptides of the present technology comprise a sequence
having
at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least
85%, at
least 90%, at least 95%, at least 98%, or at least 100% similarity with a
sequence in
region 110 of the Drpl GTPase domain in a vertebrate subject. For example, the
P110 and/or P110* sequence may contain additions and/or deletions at either
the N-
terminus or C-terminus, and/or substitutions. In one embodiment, the P110
and/or
P110* peptides of the present technology may extend beyond the Drpl GTPase
domain sequences in a vertebrate subject at the amino and/or carboxy terminus
by
about 1-5, about 1-10, about 1-15, about 1-20, about 1-25, about 1-30, about 1-
35,
about 1-40, about 1-45, or about 1-50 amino acids. In some embodiments, the
vertebrate subject is selected from the group consisting of human, mouse, rat,
chicken,
and zebrafish.
[0133] The P110* peptides of the present technology may comprise a sequence
(e.g., about 7 to about 100 amino acids, about 7 to about 60 amino acids,
about 7 to
about 50 amino acids, about 7 to about 40 amino acids, about 7 to about 30
amino
acids, about 7 to about 20 amino acids, or about 7 to about 10 amino acids in
length)
that is at least 25%, at least 30%, at least 35%, at least 40%, at least 45%,
at least
50%, at least 55%, at least 57%, at least 60%, at least 65%, or at least 67%
identical to
a sequence in region 113 of Fisl in a vertebrate subject. See Figure 2A. In
some
embodiments, the vertebrate subject is selected from the group consisting of
human,
mouse, rat, and zebrafish. In some embodiments, the sequence of the P110*
peptide
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CA 02881746 2015-02-13
is at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at
least 50%, at
least 55%, at least 57%, at least 60%, at least 65%, or at least 67% identical
to a
sequence in region 113 of Fisl in a vertebrate subject. In some embodiments,
the
vertebrate subject is selected from the group consisting of human, mouse, rat,
and
zebrafish. In some embodiments, the amino acid sequence of the P110* peptides
of
the present technology comprise a sequence having at least 40%, at least 45%,
at least
50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at
least 80%,
at least 85%, at least 90%, at least 95%, at least 98%, or at least 100%
similarity with
a sequence in region 113 of Fisl in a vertebrate subject. For example, the
P110*
sequence may contain additions and/or deletions at either the N-terminus or C-
terminus, and/or substitutions. By way of example, but not by way of
limitation, in
some embodiments, the vertebrate subject is selected from the group consisting
of
human, mouse, rat, and zebrafish.
[0134] The amino acids of the P110 and/or P110* peptides useful in the present
technology can be naturally occurring or non-naturally occurring. As used
herein, the
term "amino acid" is used to refer to any organic molecule that contains at
least one
amino group and at least one carboxyl group. In some embodiments, at least one
amino group is at the a-position relative to the carboxyl group.
[0135] In some embodiments, the amino acids of the P110* peptides are
naturally
occurring. Naturally occurring amino acids include, for example, the twenty
most
common levorotatory (L) amino acids normally found in mammalian proteins,
i.e.,
alanine (Ala), arginine (Arg), asparagine (Asn), aspartic acid (Asp), cysteine
(Cys),
glutamine (Glu), glutamic acid (Glu), glycine (Gly), histidine (His),
isoleucine (Ileu),
leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), proline
(Pro),
serine (Ser), threonine (Thr), tryptophan, (Trp), tyrosine (Tyr), and valine
(Val). By
way of example, P110 SEQ ID NOs: 3, and 10-11 include naturally occurring
amino
acids. Other naturally occurring amino acids include, for example, amino acids
that
are synthesized in metabolic processes not associated with protein synthesis.
For
example, the amino acids ornithine and citrulline are synthesized in mammalian
metabolism during the production of urea.
[0136] In some embodiments, the P110* peptides useful in the present
technology
can contain one or more non-naturally occurring amino acids. The non-naturally
occurring amino acids may be L-, dextrorotatory (D), or mixtures thereof In
some
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CA 02881746 2015-02-13
embodiments, the P110* peptide may have no amino acids that are naturally
occurring. Non-naturally occurring amino acids are those amino acids that
typically
are not synthesized in normal metabolic processes in living organisms, and do
not
naturally occur in proteins. In some embodiments, the non-naturally occurring
amino
acids useful in the present technology are not recognized by common proteases.
In
some embodiments, the non-naturally occurring amino acid is present at the N-
terminus of the P110* peptides. In some embodiments, the non-naturally
occurring
amino acid is present at the C-terminus of the P110* peptides. In some
embodiments,
the non-naturally occurring amino acid is present at a position between the N-
terminus and the C-terminus of the P110* peptides.
[0137] In some embodiments, the non-natural amino acids may, for example,
comprise alkyl, aryl, or alkylaryl groups. Some examples of alkyl amino acids
include a-aminobutyric acid, 0-aminobutyric acid, y-aminobutyric acid, (5-
aminovaleric acid, and c-aminocaproic acid. Some examples of aryl amino acids
include ortho-, meta, and para-aminobenzoic acid. Some examples of alkylaryl
amino
acids include ortho-, meta-, and para-aminophenylacetic acid, and y-pheny1-13-
aminobutyric acid. In some embodiments, the P110* peptides comprise non-
natural
amino acids such as diaminobutyric acid or diaminopropionic acid.
[0138] In other embodiments, P110* peptides comprise non-naturally occurring
amino acids that are derivatives of naturally occurring amino acids. The
derivatives
of naturally occurring amino acids may, for example, include the addition of
one or
more chemical groups to the naturally occurring amino acid. For example, one
or
more chemical groups can be added to one or more of the 2', 3', 4', 5', or 6'
position of
the aromatic ring of a phenylalanine or tyrosine residue, or the 4', 5', 6',
or 7' position
of the benzo ring of a tryptophan residue. The group can be any chemical group
that
can be added to an aromatic ring. Some examples of such groups include
branched or
unbranched CI-Ca alkyl, such as methyl, ethyl, n-propyl, isopropyl, butyl,
isobutyl, or
t-butyl, Ci-C4 alkyloxy (i.e., alkoxy), amino, CI-Ca alkylamino and Ci-C4
dialkylamino (e.g., methylamino, dimethylamino), nitro, hydroxyl, halo (i.e.,
fluoro,
chloro, bromo, or iodo). Some specific examples of non-naturally occurring
derivatives of naturally occurring amino acids include norvaline (Nva),
norleucine
(Nle), and hydroxyproline (Hyp).
48
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[0139] Another example of a modification of an amino acid in a P110* peptide
useful in the methods of the present technology is the derivatization of a
carboxyl
group of an aspartic acid or a glutamic acid residue of the peptide. One
example of
derivatization is amidation with ammonia or with a primary or secondary amine,
e.g.,
methylamine, ethylamine, dimethylamine or diethylamine. Another example of
derivatization includes esterification with, for example, methyl or ethyl
alcohol.
[0140] Another such modification includes derivatization of an amino group of
a
lysine, arginine, or histidine residue. For example, such amino groups can be
acylated. Some examples of acyl groups include a benzoyl group or an alkanoyl
group comprising any of the Ci-C4 alkyl groups mentioned above, such as an
acetyl or
propionyl group.
[0141] In some embodiments, the non-naturally occurring amino acids of the
P110*
peptides are resistant or insensitive to common proteases. Examples of non-
naturally
occurring amino acids that are resistant or insensitive to proteases include
the
dextrorotatory (D-) form of any of the above-mentioned naturally occurring L-
amino
acids, as well as L- and/or D- non-naturally occurring amino acids. The D-
amino
acids do not normally occur in proteins, although they are found in certain
peptide
antibiotics that are synthesized by means other than the normal ribosomal
protein
synthetic machinery of the cell. As used herein, the D-amino acids are
considered to
be non-naturally occurring amino acids.
[0142] In some embodiments, the P110* peptides useful in the methods of the
present technology have less than five, less than four, less than three, or
less than two
contiguous L-amino acids recognized by common proteases, irrespective of
whether
the amino acids are naturally or non-naturally occurring. In other
embodiments, the
peptide has only D-amino acids, and no L-amino acids.
[0143] In some embodiments, the P110* peptide containing protease sensitive
sequences of amino acids comprises at least one amino acid that is a non-
naturally-
occurring D-amino acid, thereby conferring protease resistance. An example of
a
protease sensitive sequence includes two or more contiguous basic amino acids
that
are readily cleaved by common proteases, such as endopeptidases and trypsin.
Examples of basic amino acids include arginine, lysine and histidine.
49
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[0144] In some embodiments, the carboxyl groups, especially the terminal
carboxyl
group of a C-terminal amino acid, may be amidated with, for example, ammonia
to
form the C-terminal amide. In other embodiments, the terminal carboxyl group
of the
C-terminal amino acid may be amidated with any primary or secondary amine. The
primary or secondary amine may, for example, be an alkyl (e.g., a branched or
unbranched Ci-C4 alkyl) or an aryl amine. Accordingly, the amino acid at the C-
terminus of the peptide may be converted to an amido, N-methylamido, N-
ethylamido, N,N-dimethylamido, N,N-diethylamido, N-methyl-N-ethylamido, N-
phenylamido or N-phenyl-N-ethylamido group.
[0145] The free carboxylate groups of the asparagine, glutamine, aspartic
acid, and
glutamic acid residues not occurring at the C-terminus of the P110* peptides
of the
present technology may also be amidated wherever they occur within the
peptide.
The amidation at these internal positions may be with ammonia or any of the
primary
or secondary amines described above.
[0146] In some embodiments, P110* peptides useful in the methods of the
present
technology are those peptides which have a tyrosine residue or a tyrosine
derivative.
Examples of derivatives of tyrosine include 2'-methyltyrosine (Mmt); 2',6'-
dimethyltyrosine (2'6'Dmt); 3',5'-dimethyltyrosine (3'5'Dmt); N,2',6'-
trimethyltyrosine (Tmt); and 2'-hydroxy-6'-methyltryosine (Hmt).
[0147] In some embodiments, P110* peptides useful in the methods of the
present
technology are those peptides which have a phenylalanine or its derivative.
Examples
of derivatives of phenylalanine include 2'-methylphenylalanine (Mmp), 2',6'-
dimethylphenylalanine (Dmp), N,2',6'-trimethylphenylalanine (Tmp), and 2'-
hydroxy-
6'-methylphenylalanine (Hmp).
[0148] P110* peptides and their derivatives can further include functional
analogues. A peptide is considered a functional analogue of P110* if the
analogue
has the same function as P110 (e.g., the same function as any one of SEQ ID
NOs: 3,
and 10-11). The analogue may, for example, be a substitution variant of P110,
wherein one or more amino acid is substituted by another amino acid. Suitable
substitution variants of P110 include conservative amino acid substitutions.
Amino
acids may be grouped according to their physicochemical characteristics as
follows:
(a) Non-polar
amino acids: Ala(A) Ser(S) Thr(T) Pro(P) Gly(G) Cys (C);
CA 02881746 2015-02-13
(b) Acidic amino acids: Asn(N) Asp(D) Glu(E) Gln(Q);
(c) Basic amino acids: His(H) Arg(R) Lys(K);
(d) Hydrophobic amino acids: Met(M) Leu(L) Ile(I) Val(V); and
(e) Aromatic amino acids: Phe(F) Tyr(Y) Trp(W) His (H).
[0149] Substitutions of an amino acid in a peptide by another amino acid in
the
same group are referred to as a conservative substitution and may preserve the
physicochemical characteristics of the original peptide. In contrast,
substitutions of
an amino acid in a peptide by another amino acid in a different group are
generally
more likely to alter the characteristics of the original peptide. The
substitutions may
also comprise amino acid analogues and mimetics. In some embodiments, the
substitutions are predicted to promote helicity or helix formation.
[0150] The P110* peptides of the present technology may be nitrosylated. In
one
embodiment, at least one cysteine residue of the peptide is nitrosylated.
[0151] The P110* peptides of the present technology may have capping,
protecting
and/or stabilizing moieties at the C-terminus and/or N-terminus. Such moieties
are
well known in the art. The P110* peptide may also be lipidated or glycosylated
at
any amino acid (i.e., a glycopeptide). In particular, these peptides may be
PEGylated
to improve druggability. The number of the PEG units (NH2(CH2CH20)CH2CH2C0)
may vary, for example, from 1 to about 50.
[0152] In some embodiments, the P110 and/or P110* peptides comprise of
fluorescent amino acids including but not limited to amino acids carrying 7-
methoxycoumariny1,13-anthraniloyl, 3-N-(7-nitro-2,1,3, benzooxadiazol-4-y1),
dansyl,
and 2-anthrylalanine. In one embodiment, the P110 and/or P110* peptide
sequence
comprises at least one13-dansyl-L-o413-diaminopropionic acid (dnsDap) amino
acid
residue. In other embodiments, the P110 and/or P110* peptide sequence
comprises at
least one 0-anthraniloy1-L-0-diaminopropionic acid (atnDap) amino acid
residue.
[0153] In some embodiments, the P110 and/or P110* peptides of the present
technology are biotinylated. Biotin binds to streptavidin and avidin with an
extremely
high affinity, fast on-rate, and high specificity. Biotin molecules can be
conjugated to
P110 and/or P110* peptides of the present technology, which allows binding of
multiple streptavidin, avidin or Neutravidin protein molecules, thereby
increasing the
sensitivity of detecting the biotinylated P110 and/or P110* peptides. In some
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embodiments, P110 and/or P110* peptides of the present technology can be
biotinylated chemically or enzymatically. Examples of chemical biotinylation
include
primary amine biotinylation, sulfhydryl biotinylation, carboxyl biotinylation,
glycoprotein biotinylation, and photoactivatable non-specific biotinylation.
Formula I, Stereoisomers, Tautomers, Solvates and Pharmaceutically Acceptable
Salts
[0154] In another aspect, the present technology provides P110* compounds of
Formula I:
CX
R5
' Cy
R6
R3 0 R11 R3 0
,...j<.,R9_,.7õ I
0 R4 R3
R14
R2 N 0 (CH2) R3 0
R12 R13
0
R 10
R3 0 R5
Ri
Formula I
or stereoisomers thereof, tautomers thereof, solvates thereof, and
pharmaceutically acceptable salts thereof; wherein
Ri is -COORa or -CONRaRa;
R2 and R14 independently are -H, -0Ra, -NRaRa, -NRaC(0)0Rb, -
NRaC(0)NRaRa,
-C(0)Ra, -Ra or a nitrogen-containing saturated or unsaturated heterocyclyl
group;
R3 at each occurrence is independently H or C1-4 alkyl;
R4 and R5 are independently a substituted or unsubstituted alkyl, alkenyl,
alkynyl, cycloalkyl, cycloalkylalkyl, aryl or aralkyl group;
R6 is -H;
R7 is -H, -0Ra, -NRaRa, a substituted or unsubstituted alkyl, cycloalkyl,
cycloalkylalkyl, or alkaryl group; or alternatively, R6 and R7 together are a
phenyl
group;
R8 is a ¨H or ORa;
R9 is -H, a substituted or unsubstituted alkyl or alkenyl group;
Rio is a ¨NReRc, -C(NRe)NRcRc, -NReC(NRc)NReRc, -NReC(0)NRcRc;
Ri is ¨H, -CN, a C i-C2 unsubstituted alkyl, or cyclopropyl group;
52
CA 02881746 2015-02-13
R12 is -H, -OR', -NR'Re, or a substituted or unsubstituted alkyl, alkenyl, or
cycloalkyl group;
R13 is ¨H or a substituted or unsubstituted alkyl group, or alternatively, R12
and R13 together are a 5- or 6-member saturated or unsaturated heterocyclyl
group;
Ra at each occurrence is independently -H, a substituted or unsubstituted
alkyl,
alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, alkaryl, or aralkyl
group;
Rb at each occurrence is independently a substituted or unsubstituted alkyl,
alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, alkaryl, or aralkyl
group;
RC at each occurrence is independently -H, or a Ci- C4 substituted or
unsubstituted alkyl group;
Cx and Cy are connected by a carbon-carbon single bond or carbon-carbon
double bond;
m is 1, 2, or 3;
n is 1,2, 3,4, or 5; and
s is 0 or 1.
[0155] In some embodiments RI is ¨COOH. In some embodiments R2 is -NH2. In
some embodiments R3 at each occurrence is ¨H. In some embodiments R4 is
isobutyl.
In some embodiments R5 is isobutyl. In some embodiments R6 is ¨H. In some
embodiments R7 is -H. In some embodiments R8 is ¨H. In some embodiments R9 is
¨
H. In some embodiments Rio is guanidino. In some embodiments Rii is ¨H. In
some
embodiments R12 is methyl. In some embodiments R13 is ¨OH. In some
embodiments R14 is ¨NH2. In some embodiments m is 1. In some embodiments n is
3. In some embodiments s is 0.
[0156] In general, "substituted" refers to an organic group as defined below
(e.g., an
alkyl group) in which one or more bonds to a hydrogen atom contained therein
are
replaced by a bond to non-hydrogen or non-carbon atoms. Substituted groups
also
include groups in which one or more bonds to a carbon(s) or hydrogen(s) atom
are
replaced by one or more bonds, including double or triple bonds, to a
heteroatom.
Thus, a substituted group is substituted with one or more substituents, unless
otherwise specified. In some embodiments, a substituted group is substituted
with 1,
2, 3, 4, 5, or 6 substituents. Examples of substituent groups include:
halogens (i.e., F,
Cl, Br, and I); hydroxyls; alkoxy, alkenoxy, aryloxy, aralkyloxy,
heterocyclyloxy, and
heterocyclylalkoxy groups; carbonyls (oxo); carboxyls; esters; urethanes;
oximes;
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CA 02881746 2015-02-13
hydroxylamines; alkoxyamines; aralkoxyamines; thiols; sulfides; sulfoxides;
sulfones;
sulfonyls; sulfonamides; amines; N-oxides; hydrazines; hydrazides; hydrazones;
azides; amides; ureas; amidines; guanidines; enamines; imides; isocyanates;
isothiocyanates; cyanates; thiocyanates; imines; nitro groups; nitriles (i.e.,
CN); and
the like.
[0157] Substituted ring groups such as substituted cycloalkyl, aryl, and
heterocyclyl
groups also include rings and ring systems in which a bond to a hydrogen atom
is
replaced with a bond to a carbon atom. Therefore, substituted cycloalkyl,
aryl, and
heterocyclyl groups may also be substituted with a substituted or
unsubstituted alkyl,
alkenyl, and alkynyl groups as defined below.
[0158] Alkyl groups include straight chain and branched chain alkyl groups
having
from from 1 to 10 carbons or, and typically, from 1 to 8, in some embodiments,
1 to 6,
or 1 to 4 carbon atoms. Examples of straight chain alkyl groups include groups
such
as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl
groups.
Examples of branched alkyl groups include, but are not limited to, isopropyl,
iso-
butyl, sec-butyl, tert-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl
groups.
Representative substituted alkyl groups may be substituted one or more times
with
substituents such as those listed above, and include without limitation
haloalkyl (e.g.,
trifluoromethyl), hydroxyalkyl, thioalkyl, aminoalkyl, alkylaminoalkyl,
dialkylaminoalkyl, alkoxyalkyl, carboxyalkyl, and the like.
[0159] Cycloalkyl groups include mono-, bi- or tricyclic alkyl groups having
from 3
to 10 carbon atoms in the ring(s), or, in some embodiments, 3 to 8, or 3 to 4,
5, or 6
carbon atoms. Exemplary monocyclic cycloalkyl groups include, but not limited
to,
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl
groups.
In some embodiments, the cycloalkyl group has 3 to 8 ring members, whereas in
other
embodiments the number of ring carbon atoms range from 3 to 5, 3 to 6, or 3 to
7. Bi-
and tricyclic ring systems include both bridged cycloalkyl groups and fused
rings,
such as, but not limited to, bicyclo[2.1.11hexane, adamantyl, decalinyl, and
the like.
Substituted cycloalkyl groups may be substituted one or more times with, non-
hydrogen and non-carbon groups as defined above. However, substituted
cycloalkyl
groups also include rings that are substituted with straight or branched chain
alkyl
groups as defined above. Representative substituted cycloalkyl groups may be
mono-
substituted or substituted more than once, such as, but not limited to, 2,2-,
2,3-, 2,4-
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2,5- or 2,6-disubstituted cyclohexyl groups, which may be substituted with
substituents such as those listed above.
[0160] Cycloalkylalkyl groups are alkyl groups as defined above in which a
hydrogen or carbon bond of an alkyl group is replaced with a bond to a
cycloalkyl
group as defined above. In some embodiments, cycloalkylalkyl groups have from
4
to 12 carbon atoms, and typically 4 to 10 carbon atoms. Substituted
cycloalkylalkyl
groups may be substituted at the alkyl, the cycloalkyl or both the alkyl and
cycloalkyl
portions of the group. Representative substituted cycloalkylalkyl groups may
be
mono-substituted or substituted more than once, such as, but not limited to,
mono-, di-
or tri-substituted with substituents such as those listed above.
[0161] Alkenyl groups include straight and branched chain alkyl groups as
defined
above, except that at least one double bond exists between two carbon atoms.
Alkenyl groups have from 2 to 10 carbon atoms, and typically from 2 to 8
carbons or,
in some embodiments, from 2 to 6, or 2 to 4 carbon atoms. In some embodiments,
the
alkenyl group has one, two, or three carbon-carbon double bonds. Examples
include,
but are not limited to vinyl,
allyl, -CH=CH(CH3), -CH=C(CH3)2, -C(CH3)=CH2, -C(CH3)=CH(CH3), -C(CH2CH3)
=CH2, among others. Representative substituted alkenyl groups may be
mono-substituted or substituted more than once, such as, but not limited to,
mono-, di-
or tri-substituted with substituents such as those listed above.
[0162] Cycloalkenyl groups include cycloalkyl groups as defined above, having
at
least one double bond between two carbon atoms. In some embodiments the
cycloalkenyl group may have one, two or three double bonds but does not
include
aromatic compounds. Cycloalkenyl groups have from 4 to 12 carbon atoms, or, in
some embodiments, 5 to 10 carbon atoms, or even 5, 6, 7, or 8 carbon atoms.
Examples of cycloalkenyl groups include cyclohexenyl, cyclopentenyl,
cyclohexadienyl, butadienyl, pentadienyl, and hexadienyl.
[0163] Cycloalkenylalkyl groups are alkyl groups as defined above in which a
hydrogen or carbon bond of the alkyl group is replaced with a bond to a
cycloalkenyl
group as defined above. Substituted cycloalkenylalkyl groups may be
substituted at
the alkyl, the cycloalkenyl or both the alkyl and cycloalkenyl portions of the
group.
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Representative substituted cycloalkenylalkyl groups may be substituted one or
more
times with substituents such as those listed above.
[0164] Alkynyl groups include straight and branched chain alkyl groups as
defined
above, except that at least one triple bond exists between two carbon atoms.
Alkynyl
groups have from 2 to 10 carbon atoms, and typically from 2 to 8 carbons or,
in some
embodiments, from 2 to 6, or 2 to 4 carbon atoms. In some embodiments, the
alkynyl
group has one, two, or three carbon-carbon triple bonds. Examples include, but
are
not limited to ¨C H, -C CH3, -CH2C CH3, -C CH2CH(CH2CH3)2, among
others. Representative substituted alkynyl groups may be mono-substituted or
substituted more than once, such as, but not limited to, mono-, di- or tri-
substituted
with substituents such as those listed above.
[0165] Aryl groups are cyclic aromatic hydrocarbons that do not contain
heteroatoms. Aryl groups herein include monocyclic, bicyclic and tricyclic
ring
systems. Thus, aryl groups include, but are not limited to, phenyl, azulenyl,
heptalenyl, biphenyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, indanyl,
pentalenyl, and naphthyl groups. In some embodiments, aryl groups contain 6-12
carbons, and in others from 6 to 10 or even 5-8 carbon atoms in the ring
portions of
the groups. In some embodiments, the aryl groups are phenyl or naphthyl.
Although
the phrase "aryl groups" includes groups containing fused rings, such as fused
aromatic-aliphatic ring systems (e.g., indanyl, tetrahydronaphthyl, and the
like), it
does not include aryl groups that have other groups, such as alkyl or halo
groups,
bonded to one of the ring members. Rather, groups such as chlorophenyl or
tolyl are
referred to as substituted aryl groups. Alkyl substituted aryl groups may also
be
referred to as alkaryl groups. Phenyl groups are aryl groups (i.e., cyclic
aromatic
hydrocarbons that do not contain heteroatoms). Phenyl groups are cyclic -C6H5
systems with alternating carbon-carbon double bonds in which one or more bonds
to a
hydrogen(s) atom may be replaced by one or more bonds to an alkyl or
substituent
group as defined above.
[0166] Alkaryl groups are substituted aryl groups as defined above in which
cyclic
aromatic hydrocarbons that do not contain heteroatoms are substituted with 1
or more
alkyl groups as defined above. Substituted alkaryl groups may be substituted
at the
aryl, the alkyl, or both the aryl and alkyl portions of the group.
Representative
substituted alkaryl groups may be substituted one or more times with
substituents
56
CA 02881746 2015-02-13
such as those listed above. Representative substituted aryl groups may be mono-
substituted or substituted more than once. For example, monosubstituted aryl
groups
include, but are not limited to, 2-, 3-, 4-, 5-, or 6-substituted phenyl or
naphthyl
groups, which may be substituted with substituents such as those listed above.
Representative substituted and unsubstituted alkaryl groups include but are
not limited
to alkylphenyl such as methylphenyl, (chloromethyl)phenyl,
chloro(chloromethyl)phenyl, or fused alkaryl groups such as 5-
ethylnaphthalenyl.
[0167] Aralkyl groups are alkyl groups as defined above in which a hydrogen or
carbon bond of an alkyl group is replaced with a bond to an aryl group as
defined
above. In some embodiments, aralkyl groups contain 6 to 12 carbon atoms, 6 to
10
carbon atoms, or 6 to 8 carbon atoms. Substituted aralkyl groups may be
substituted
at the alkyl, the aryl or both the alkyl and aryl portions of the group.
Representative
aralkyl groups include but are not limited to benzyl and phenethyl groups and
fused
(cycloalkylaryl)alkyl groups such as 4-indanylethyl. Representative
substituted
aralkyl groups may be substituted one or more times with substituents such as
those
listed above.
[0168] Except as specified herein, heterocyclyl groups include aromatic (also
referred to as heteroaryl) and non-aromatic ring compounds containing 3 or
more ring
members, of which one or more is a heteroatom such as, but not limited to, N,
0, and
S. In some embodiments, the heterocyclyl group contains 1, 2, 3 or 4
heteroatoms. In
some embodiments, heterocyclyl groups include mono-, bi- and tricyclic rings
having
3 to 12 ring members, whereas other such groups have 3 to 6, 3 to 8, or 3 to
10 ring
members. Heterocyclyl groups encompass aromatic, partially unsaturated and
saturated ring systems, such as, for example, imidazolyl, imidazolinyl and
imidazolidinyl groups. The phrase "heterocyclyl group" includes fused ring
species
including those comprising fused aromatic and non-aromatic groups, such as,
for
example, benzotriazolyl, 2,3-dihydrobenzo[1,4]dioxinyl, and
benzo[1,3]dioxolyl. The
phrase also includes bridged polycyclic ring systems containing a heteroatom
such as,
but not limited to, quinuclidyl. However, the phrase does not include
heterocyclyl
groups that have other groups, such as alkyl, oxo or halo groups, bonded to
one of the
ring members. Rather, these are referred to as "substituted heterocyclyl
groups".
Heterocyclyl groups include, but are not limited to, aziridinyl, azetidinyl,
pyrrolidinyl,
imidazolidinyl, pyrazolidinyl, thiazolidinyl, tetrahydrothiophenyl,
tetrahydrofuranyl,
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CA 02881746 2015-02-13
dioxolyl, furanyl, thiophenyl, pyrrolyl, pyrrolinyl, imidazolyl, imidazolinyl,
pyrazolyl,
pyrazolinyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl,
thiazolinyl,
isothiazolyl, thiadiazolyl, oxadiazolyl, piperidyl, piperazinyl, morpholinyl,
thiomorpholinyl, tetrahydropyranyl, tetrahydrothiopyranyl, oxathiane, dioxyl,
dithianyl, pyranyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl,
dihydropyridyl, dihydrodithiinyl, dihydrodithionyl, homopiperazinyl,
quinuclidyl,
indolyl, indolinyl, isoindolyl,azaindoly1 (pyrrolopyridyl), indazolyl,
indolizinyl,
benzotriazolyl, benzimidazolyl, benzofuranyl, benzothiophenyl, benzthiazolyl,
benzoxadiazolyl, benzoxazinyl, benzodithiinyl, benzoxathiinyl, benzothiazinyl,
benzoxazolyl, benzothiazolyl, benzothiadiazolyl, benzo[1,3]dioxolyl,
pyrazolopyridyl,
imidazopyridyl (azabenzimidazolyl), triazolopyridyl, isoxazolopyridyl,
purinyl,
xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl, quinolizinyl,
quinoxalinyl,
quinazolinyl, cinnolinyl, phthalazinyl, naphthyridinyl, pteridinyl,
thianaphthyl,
dihydrobenzothiazinyl, dihydrobenzofuranyl, dihydroindolyl,
dihydrobenzodioxinyl,
tetrahydroindolyl, tetrahydroindazolyl, tetrahydrobenzimidazolyl,
tetrahydrobenzotriazolyl, tetrahydropyrrolopyridyl, tetrahydropyrazolopyridyl,
tetrahydroimidazopyridyl, tetrahydrotriazolopyridyl, and tetrahydroquinolinyl
groups.
Representative substituted heterocyclyl groups may be mono-substituted or
substituted more than once, such as, but not limited to, pyridyl or
morpholinyl groups,
which are 2-, 3-, 4-, 5-, or 6-substituted, or disubstituted with various
substituents
such as those listed above.
[0169] Heterocyclylalkyl groups are alkyl groups as defined above in which a
hydrogen or carbon bond of an alkyl group is replaced with a bond to a
heterocyclyl
group as defined above. Substituted heterocyclylalkyl groups may be
substituted at
the alkyl, the heterocyclyl or both the alkyl and heterocyclyl portions of the
group.
Representative heterocyclyl alkyl groups include, but are not limited to,
morpholin-4-
yl-ethyl, furan-2-yl-methyl, imidazol-4-yl-methyl, pyridin-3-yl-methyl,
tetrahydrofuran-2-yl-ethyl, and indo1-2-yl-propyl. Representative substituted
heterocyclylalkyl groups may be substituted one or more times with
substituents such
as those listed above.
[0170] Groups described herein having two or more points of attachment (i.e.,
divalent, trivalent, or polyvalent) within the compound of the present
technology are
designated by use of the suffix, "ene." For example, divalent alkyl groups are
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CA 02881746 2015-02-13
alkylene groups, divalent aryl groups are arylene groups, divalent heteroaryl
groups
are divalent heteroarylene groups, and so forth. Substituted groups having a
single
point of attachment to the compound of the present technology are not referred
to
using the "ene" designation. Thus, e.g., chloroethyl is not referred to herein
as
chloroethylene.
[0171] Alkoxy groups are hydroxyl groups (-OH) in which the bond to the
hydrogen
atom is replaced by a bond to a carbon atom of a substituted or unsubstituted
alkyl
group as defined above. Examples of linear alkoxy groups include but are not
limited
to methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, and the like. Examples
of
branched alkoxy groups include but are not limited to isopropoxy, sec-butoxy,
tert-
butoxy, isopentoxy, isohexoxy, and the like. Examples of cycloalkoxy groups
include
but are not limited to cyclopropyloxy, cyclobutyloxy, cyclopentyloxy,
cyclohexyloxy,
and the like. Representative substituted alkoxy groups may be substituted one
or
more times with substituents such as those listed above.
[0172] The terms "alkanoyl" and "alkanoyloxy" as used herein can refer,
respectively, to ¨C(0)¨alkyl groups and ¨0¨C(0)¨alkyl groups, each containing
2-5
carbon atoms.
[0173] The terms "aryloxy" and "arylalkoxy" refer to, respectively, a
substituted or
unsubstituted aryl group bonded to an oxygen atom and a substituted or
unsubstituted
aralkyl group bonded to the oxygen atom at the alkyl. Examples include but are
not
limited to phenoxy, naphthyloxy, and benzyloxy. Representative substituted
aryloxy
and arylalkoxy groups may be substituted one or more times with substituents
such as
those listed above.
[0174] The term "carboxylate" as used herein refers to a -COOH group.
[0175] The term "ester" as used herein refers to ¨COOR3 groups. R3 is a
substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl,
aralkyl,
heterocyclylalkyl or heterocyclyl group as defined herein.
[0176] The term "amide" (or "amido") includes C- and N-amide groups,
i . e . , - C (0)NR3 I R3 2 , and ¨NR31C(0)R32 groups, respectively. R31 and
R32 are
independently hydrogen, or a substituted or unsubstituted alkyl, alkenyl,
alkynyl,
cycloalkyl, aryl, aralkyl, heterocyclylalkyl or heterocyclyl group as defined
herein.
Amido groups therefore include but are not limited to carbamoyl groups (-
C(0)NH2)
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and formamide groups (-NHC(0)H). In some embodiments, the amide is ¨
NR31C(0)-(C15 alkyl) and the group is termed "carbonylamino," and in others
the
amide is ¨NHC(0)-alkyl and the group is termed "alkanoylamino."
[0177] The term "nitrile" or "cyano" as used herein refers to the ¨CN group.
[0178] Urethane groups include N- and 0-urethane groups, i.e., -NR33C(0)0R34
and -0C(0)NR33R34 groups, respectively. R33 and R34 are independently a
substituted
or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl,
heterocyclylalkyl, or
heterocyclyl group as defined herein. R33 may also be H.
[0179] The term "amine" (or "amino") as used herein refers to -NR35R36 groups,
wherein R35 and R36 are independently hydrogen, or a substituted or
unsubstituted
alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heterocyclylalkyl or
heterocyclyl
group as defined herein. In some embodiments, the amine is alkylamino,
dialkylamino, arylamino, or alkylarylamino. In other embodiments, the amine is
NH2,
methylamino, dimethylamino, ethylamino, diethylamino, propylamino,
isopropylamino, phenylamino, or benzylamino.
[0180] The term "sulfonamido" includes S- and N-sulfonamide groups,
i.e., -S02NR38R39 and ¨NR38S02R39 groups, respectively. R38 and R39 are
independently hydrogen, or a substituted or unsubstituted alkyl, alkenyl,
alkynyl,
cycloalkyl, aryl, aralkyl, heterocyclylalkyl, or heterocyclyl group as defined
herein.
Sulfonamido groups therefore include but are not limited to sulfamoyl groups (-
SO2NH2). In some embodiments herein, the sulfonamido is ¨NHS02-alkyl and is
referred to as the "alkylsulfonylamino" group.
[0181] The term "thiol" refers to ¨SH groups, while sulfides include ¨SR4
groups,
sulfoxides include ¨S(0)R41 groups, sulfones include -S021e2 groups, and
sulfonyls
include ¨S020R43. R40, R41, IC-425
and R43 are each independently a substituted or
unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl aralkyl, heterocyclyl
or
heterocyclylalkyl group as defined herein. In some embodiments the sulfide is
an
alkylthio group, -S-alkyl.
[0182] The term "urea" refers to ¨NR44_C(0)-NR45R46 groups. R44, R45, and R46
groups are independently hydrogen, or a substituted or unsubstituted alkyl,
alkenyl,
alkynyl, cycloalkyl, aryl, aralkyl, heterocyclyl, or heterocyclylalkyl group
as defined
herein.
CA 02881746 2015-02-13
[0183] The term "amidine" refers to ¨C(NR47)NR48R49 and -NR47C(NR48)R49,
wherein R47, R48, and R49 are each independently hydrogen, or a substituted or
unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl aralkyl, heterocyclyl
or
heterocyclylalkyl group as defined herein.
[0184] The term "guanidine" refers to -NR50C(NR51)NR52R53, wherein R50, R51,
R52
and R53 are each independently hydrogen, or a substituted or unsubstituted
alkyl,
cycloalkyl, alkenyl, alkynyl, aryl aralkyl, heterocyclyl or heterocyclylalkyl
group as
defined herein.
[0185] The term "enamine" refers to ¨C(R54)=-C(R55)NR56R57
and -NR54C(R55)=C(R56)R57, wherein R54, R", R56 and R57 are each independently
hydrogen, a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl,
aryl
aralkyl, heterocyclyl or heterocyclylalkyl group as defined herein.
[0186] The term "halogen" or "halo" as used herein refers to bromine,
chlorine,
fluorine, or iodine. In some embodiments, the halogen is fluorine. In other
embodiments, the halogen is chlorine or bromine.
[0187] The term "hydroxy' as used herein can refer to ¨OH or its ionized form,
[0188] The term "imide" refers to ¨C(0)NR58C(0)R59, wherein R58 and R59 are
each independently hydrogen, or a substituted or unsubstituted alkyl,
cycloalkyl,
alkenyl, alkynyl, aryl aralkyl, heterocyclyl or heterocyclylalkyl group as
defined
herein.
[0189] The term "imine" refers to _cR6o(N=-=K61,
) and ¨N(CR6 ,+61
K ) groups, wherein
R6 and R6' are each independently hydrogen or a substituted or unsubstituted
alkyl,
cycloalkyl, alkenyl, alkynyl, aryl aralkyl, heterocyclyl or heterocyclylalkyl
group as
defined herein, with the proviso that R6 and R61 are not both simultaneously
hydrogen.
[0190] The term "nitro" as used herein refers to an ¨NO2 group.
Mitochondrial Diseases
[0191] Mitochondrial dysfunction plays a role both in the pathogenesis of late-
onset
neurodegenerative disorders, including Parkinson disease (PD), Huntington
disease
(HD), Alzheimer disease (AD), and amyotrophic lateral sclerosis (ALS), and in
the
pathogenesis of aging.
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[0192] Mitochondrial diseases are a clinically heterogeneous group of
disorders that
arise as a result of dysfunction of the mitochondrial respiratory chain. The
mitochondrial respiratory chain is the only metabolic pathway in the cell that
is under
the dual control of the mitochondrial genome (mtDNA) and the nuclear genome
(nDNA). While some mitochondrial disorders only affect a single organ (e.g.,
the eye
in Leber hereditary optic neuropathy [LHON]), many involve multiple organ
systems
and often present with prominent neurologic and myopathic features.
Mitochondrial
disorders may present at any age.
[0193] Mutations in mtDNA can be divided into those that impair mitochondrial
protein synthesis in toto and those that affect any one of the 13 respiratory
chain
subunits encoded by mtDNA.
(i) Heteroplasmy and threshold effect. Each cell contains hundreds or
thousands of mtDNA copies, which, at cell division, distribute randomly among
daughter cells. In normal tissues, all mtDNA molecules are identical
(homoplasmy).
Deleterious mutations of mtDNA usually affect some but not all mtDNAs within a
cell, a tissue, or an individual (heteroplasmy). The clinical expression of a
pathogenic
mtDNA mutation is largely determined by the relative proportion of normal and
mutant mtDNA genomes in different tissues. A minimum critical number of mutant
mtDNAs is required to cause mitochondrial dysfunction in a particular organ or
tissue
(threshold effect).
(ii) Mitotic segregation. At cell division, the proportion of mutant mtDNAs in
daughter cells may shift and the phenotype may change accordingly. This
phenomenon, called mitotic segregation, explains how certain patients with
mtDNA-
related disorders may actually manifest different mitochondrial diseases at
different
stages of their lives.
(iii) Maternal inheritance. At fertilization, all mtDNA derives from the
oocyte. Therefore, the mode of transmission of mtDNA and of mtDNA point
mutations (single deletions of mtDNA are usually sporadic events) differs from
Mendelian inheritance. A mother carrying a mtDNA point mutation will pass it
on to
all her children (males as well as females), but only her daughters will
transmit it to
their progeny. A disease expressed in both sexes but with no evidence of
paternal
transmission is strongly suggestive of a mtDNA point mutation.
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[0194] Many individuals with a mutation of mtDNA display a cluster of clinical
features that fall into a discrete clinical syndrome, such as the Kearns-Sayre
syndrome
(KSS), chronic progressive external ophthalmoplegia, mitochondrial
encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS),
myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with
ataxia and retinitis pigmentosa (NARP), or Leigh syndrome (LS). However,
considerable clinical variability exists and many individuals do not fit
neatly into one
particular category, which is well-illustrated by the overlapping spectrum of
disease
phenotypes (including mitochondrial recessive ataxia syndrome (MIRAS)
resulting
from mutation of the nuclear gene POLG, which has emerged as a major cause of
mitochondrial disease.
[0195] Disorders due to mutations in nDNA are more abundant not only because
most respiratory chain subunits are nucleus-encoded but also because correct
assembly and functioning of the respiratory chain require numerous steps, all
of
which are under the control of nDNA. These steps (and related diseases)
include: (i)
synthesis of assembly proteins; (ii) intergenomic signaling; (iii)
mitochondrial
importation of nDNA-encoded proteins; (iv) synthesis of inner mitochondrial
membrane phospholipids; (v) mitochondrial motility and fission.
[0196] Common clinical features of mitochondrial disease ¨ whether involving a
mitochondrial or nuclear gene ¨ include ptosis, external ophthalmoplegia,
proximal
myopathy and exercise intolerance, cardiomyopathy, sensorineural deafness,
optic
atrophy, pigmentary retinopathy, and diabetes mellitus. Common central nervous
system findings are fluctuating encephalopathy, seizures, dementia, migraine,
stroke-
like episodes, ataxia, and spasticity. A high incidence of mid- and late
pregnancy loss
is a common occurrence that often goes unrecognized.
[0197] Mitochondrial myopathies are characterized by excessive proliferation
of
normal- or abnormal-looking mitochondria in the muscle of patients with
weakness or
exercise intolerance. These abnormal fibers are referred to as "ragged red
fibers"
because the areas of mitochondrial accumulation appear purplish when contacted
with
the modified Gomori trichrome stain. Many patients with ragged red fibers
often
exhibit encephalomyopathy. However, the absence of ragged red fibers in a
biopsy
does not exclude a mitochondrial etiology.
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[0198] Diagnosis. In some subjects, the clinical picture is characteristic of
a
specific mitochondrial disorder (e.g., LHON, NARP, or maternally inherited
Leigh
Syndrome), and the diagnosis can be confirmed by identification of a mtDNA
mutation on molecular genetic testing of DNA extracted from a blood sample. In
many individuals, such is not the case, and a more structured approach is
needed,
including family history, blood and/or CSF lactate concentration,
neuroimaging,
cardiac evaluation, and molecular genetic testing for a mtDNA or nuclear gene
mutation. Approaches to molecular genetic testing of a proband to consider are
serial
testing of single genes, multi-gene panel testing (simultaneous testing of
multiple
genes), and/or genomic testing (e.g., sequencing of the entire mitochondrial
genome
exome or exome sequencing to identify mutation of a nuclear gene). In many
individuals in whom molecular genetic testing does not yield or confirm a
diagnosis,
further investigation of suspected mitochondrial disease can involve a range
of
different clinical tests, including muscle biopsy for respiratory chain
function.
[0199] A brief nonexhaustive summary of the various mitochondrial diseases or
disorders is provided below.
Alexander Disease
[0200] In decreasing order of frequency, 3 forms of Alexander disease are
recognized, based on age of onset: infantile, juvenile, and adult. Younger
patients
typically present with seizures, megalencephaly, developmental delay, and
spasticity.
In older patients, bulbar or pseudobulbar symptoms predominate, frequently
accompanied by spasticity. The disease is progressive, with most patients
dying
within 10 years of onset. Imaging studies of the brain typically show cerebral
white
matter abnormalities, preferentially affecting the frontal region. All 3 forms
have
been shown to be caused by autosomal dominant mutations in the GFAP (Glial
fibrillary acidic protein) gene. Some patients with Alexander disease also
exhibit
mutations in NADH-Ubiquinone Oxidoreductase Flavoprotein 1 (NDUFV1).
[0201] Histologically, Alexander disease is characterized by Rosenthal fibers,
homogeneous eosinophilic masses which form elongated tapered rods up to 30
microns in length, which are scattered throughout the cortex and white matter
and are
most numerous in the subpial, perivascular and subependymal regions. These
fibers
are located in astrocytes, cells that are closely related to blood vessels.
Demyelination
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is present, usually as a prominent feature. A few cases have had
hydrocephalus.
Rosenthal fibers are commonly found in astrocytomas, optic nerve gliomas and
states
of chronic reactive gliosis, but they are especially conspicuous in Alexander
disease. Rosenthal fibers found in this situation are typically the result of
degenerative changes in the cytoplasm and cytoplasmic processes of astrocytic
glial
cell.
Alpers-Huttenlocher Disease (Alpers
[0202] Mitochondrial DNA Depletion Syndrome-4A, also known as Alpers
Syndrome, is an autosomal recessive disorder caused by mutations in POLG.
Alpers
is characterized by a clinical triad of psychomotor retardation, intractable
epilepsy,
and liver failure in infants and young children. Pathologic findings include
neuronal
loss in the cerebral gray matter with reactive astrocytosis and liver
cirrhosis. The
disorder is progressive and often leads to death from hepatic failure or
status
epilepticus before age 3 years. Symptoms include anoxic encephalopathy, fever,
developmental delay, epilepsy, impaired central visual function, ataxia,
sensory loss,
neuronal loss, progressive liver failure, acute liver dysfunction precipitated
by
valproic acid, cirrhosis, hypotonia, dementia, vomiting, paralysis, stupor,
jaundiced
liver with fibrosis, inflammation and bile duct proliferation, and increased
CSF
protein and lactate.
[0203] Some affected individuals may show mild intermittent 3-methylglutaconic
aciduria and defects in mitochondrial oxidative phosphorylation. Subjects with
Alpers typically exhibit perturbations in pyruvate metabolism and NADH
oxidation.
For example, a subset of patients with mtDNA depletion and Alpers Syndrome
show
a global reduction in respiratory chain complex I, II/IIL and IV activity and
deficiency
of mitochondrial DNA polymerase gamma activity. Neuropathologic changes
characteristic of Alpers Syndrome, namely laminar cortical necrosis, may also
be seen
in some patients with combined oxidative phosphorylation deficiency-14
(COXPD14)
due to a mutation in the FARS2 gene.
Alpha-ketoglutarate Dehydrogenase Deficiency
[0204] Alpha-ketoglutarate dehydrogenase (AKDGH) deficiency is a disease of
the
tricarboxylic acid cycle (TCA cycle) that affects mitochondria metabolism.
Alpha-
ketoglutarate dehydrogenase is an enzyme of the TCA cycle that catalyzes the
CA 02881746 2015-02-13
oxidation of alpha-ketoglutarate to succinyl CoA. Alpha-ketoglutarate
dehydrogenase
is one of 3 alpha-ketoacid dehydrogenases, the others being pyruvate
dehydrogenase
and branched-chain ketoacid dehydrogenase. The alpha-ketoglutarate
dehydrogenase
complex is a multi-enzyme complex consisting of three protein subunits:
oxoglutarate
dehydrogenase, also known as alpha-ketoglutarate dehydrogenase or Elk;
dihydrolipoyl succinyltransferase, also known as DLST or E2k; and
dihydrolipoyl
dehydrogenase, also known as DLD or E3. AKDGH deficiency is associated with
DLD deficiency, which is caused by a mutation in the DLD gene. AKDGH
deficiency is characterized by encephalopathy and hyperlactatemia resulting in
death
in early childhood.
Frontotemporal Dementia and/or Amyotrophic Lateral Sclerosis (ALS-FTD)
[0205] ALS-FTD is an autosomal dominant late-onset (between 49 to 65 years)
neurodegenerative disorder comprising frontotemporal dementia, cerebellar
ataxia,
myopathy, and motor neuron disease consistent with amyotrophic lateral
sclerosis,
caused by disruptions in the CHCHD10 gene. Clinical manifestations include
progressive bulbar dysfunction, dementia, sensorineural deafness, extensor
plantar
responses, dysphagia, dysarthria, myopathy, and a frontal lobe syndrome.
Muscle
biopsies usually show ragged red fibers, cytochrome C oxidase (COX)-negative
fibers, and mitochondrial DNA deletions; many patients also have combined
mitochondrial respiratory chain deficiencies and fragmented mitochondrial
networks
in fibroblasts, all suggestive of mitochondrial dysfunction. Other features
include
signs of Parkinsonism, including akinesia and rigidity, sensorineural
hypoacusis, and
fatigue. Overexpression of the mutant CHCHD10 protein in HeLa cells results in
fragmentation of the mitochondrial network as well as major ultrastructural
abnormalities, thereby implicating a role for dysfunctional mitochondria in
the
pathogenesis of late-onset frontotemporal dementia with motor neuron disease.
Anemia
1. Sideroblastic Anemia with Spinocerebellar Ataxia
[0206] Sideroblastic anemia with spinocerebellar ataxia is caused by mutations
in
the ATP-binding cassette 7 (ABCB7) transporter, which mediates ATP-dependent
transfer of solutes. ABCB7 is an inner mitochondrial membrane protein that
contains
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2 transmembrane domains that form a membranous pore and 2 cytosolic ATP-
binding
domains, which couple ATP binding to solute movement. Affected males exhibit a
moderate hypochromic microcytic anemia with ring sideroblasts on bone marrow
examination and raised free erythrocyte protoporphyrin levels and no excessive
parenchymal iron storage in adulthood. Neurologic features include non-
progressive
ataxia or incoordination (age of onset at 1 year), accompanied by long motor
tract
signs (hyperactive deep tendon reflexes, positive Babinski sign, clonus) in
young
affected males. Heterozygous females may exhibit mild anemia, but not ataxia.
2. Sideroblastic Anemia, Pyridoxine-refractory
[0207] Pyridoxine-refractory sideroblastic anemia is an autosomal recessive
disorder caused by a homozygous or compound heterozygous mutation in the
SLC25A38 gene. In addition, a homozygous mutation in the GLRX5 gene has been
identified in some patients with late-onset autosomal recessive pyridoxine-
refractory
sideroblastic anemia. Clinical features include severe microcytic hypochromic
anemia, hepatosplenomegaly, jaundice, iron overload, and cirrhosis. Patients
typically exhibit moderate erythroid expansion in the bone marrow, and
increased iron
staining both in erythroblasts and macrophages, with 28% ringed sideroblasts.
In
some cases, patients may show low levels of b-aminolevulinic acid synthase in
erythroblasts.
3. Growth Retardation, Amino aciduria, Cholestasis, Iron overload, Lactic
acidosis, Early death (GRACILE) Syndrome
[02081 GRACILE Syndrome, an autosomal recessive disorder usually observed in
Finnish and Turkish populations, is caused by disruptions in the BCSIL gene
which is
required for the expression of functional ubiquinol-cytochrome-c reductase (be
1)
complex. Loss of BCSIL function results in tubulopathy, encephalopathy, and
liver
failure due to complex III deficiency. Clinical features include severe
intrauterine
growth retardation, fulminant lactic acidosis during the first days of life,
Fanconi-type
amino aciduria, spasticity, increased tendon reflexes, and abnormalities in
iron
metabolism, including liver hemosiderosis. Affected infants fail to thrive,
and die
neonatally or in early infancy. Other BCS1L disorders include Bjornstad
Syndrome,
Leigh Syndrome and mitochondrial complex III deficiency, nuclear type 1
(MC3DN1).
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4. Anemia and Mitochondriopathy (COXPD18)
[0209] Anemia and mitochondriopathy, or combined oxidative phosphorylation
deficiency 18 (COXPD18) is an autosomal recessive disorder caused by a
homozygous or compound heterozygous mutation in the SFXN4. COXPD18 is
characterized by intrauterine growth retardation, intellectual disability,
dysmetria,
tremor, muscular atrophy, hypotonia, visual impairment, speech delay, delayed
motor
skills, and lactic acidosis associated with decreased mitochondrial
respiratory chain
activity. Affected patients may also show hematologic abnormalities, mainly
macrocytic anemia and hypersegmented neutrophils, and increased blood lactate
and
ammonia levels.
5. Thiamine-responsive Megaloblastic Anemia
[0210] Thiamine-responsive Megaloblastic Anemia Syndrome (TRMA), also
known as Thiamine Metabolism Dysfunction Syndrome-1 (THMD1), can be caused
by a homozygous mutation in the SLC19A2 gene, which encodes a thiamine
transporter protein. Thiamine-responsive Megaloblastic Anemia Syndrome
comprises megaloblastic anemia, diabetes mellitus, amino aciduria, and
sensorineural
deafness. Onset is typically between infancy and adolescence, but all of the
cardinal
findings are often not present initially. The anemia, and sometimes the
diabetes,
improves with high doses of thiamine. Other more variable features include
optic
atrophy, congenital heart defects, short stature, and stroke.
6. Pearson Syndrome
[0211] Pearson Syndrome is caused by a deletion in mitochondrial DNA and is
characterized by sideroblastic anemia and exocrine pancreas dysfunction. With
Pearson Syndrome, the bone marrow fails to produce white blood cells called
neutrophils. The syndrome also leads to anemia, low platelet count, and
aplastic
anemia. Pearson Syndrome causes the exocrine pancreas to not function properly
because of scarring and atrophy. Individuals with this condition have
difficulty
absorbing nutrients from their diet which leads to malabsorption. Infants with
this
condition generally do not grow or gain weight
[0212] Other clinical features are failure to thrive, pancytopenic crises,
pancreatic
fibrosis with insulin-dependent diabetes and exocrine pancreatic
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deficiency, muscle and neurologic impairment, malabsorption, steatorrhea,
metabolic
and lactic acidosis, and early death. The few patients who survive into
adulthood
often develop symptoms of Kearns-Sayre Syndrome.
Ataxia
[0213] Ataxia is defined as the presence of abnormal, uncoordinated movements.
Defects affecting either the mitochondria' or nuclear genomes can cause
mitochondria' dysfunction, resulting in mitochondrial ataxia. Ataxia
associated with
mtDNA defects typically manifests as part of a multisystem, multisyndrome
disorder.
Maternally Inherited Ataxias
HAM Syndrome
[0214] HAM (Hearing loss, Ataxia, Myoclonus) is a maternally-inherited
syndrome
characterized by a combination of sensorineural hearing loss, ataxia, and
myoclonus
observed in a large kindred from Sicily. Hearing loss is the most prevalent
and
sometimes the only symptom found in family members. HAM Syndrome is
associated with the presence of a C7472 insertion mutation in mtDNA regions
encompassing the tRNA genes. This particular insertion is found in the MT-TS1
gene
(nucleotides 7445-7516), which encodes the mitochondrial tRNA for serine
(UCN).
The insertion adds a seventh cytosine to a six-cytosine run that is part of
the
mitochondrial tRNASer(UCN) gene. Conformational analyses demonstrate that this
mutation likely alters the clover leaf secondary structure of tRNASer/(UCN).
Ataxia, Cataract, and Diabetes Syndrome and MELAS/MERRF Overlap Syndrome
[0215] Mutations in the mitochondria' MT-TS2 gene (nucleotides 12207-12265),
which encodes the mitochondria' tRNA for serine (AGY) are associated with the
development of maternally-inherited cerebellar ataxia, cataract, and diabetes
mellitus.
In particular, these phenotypes are associated with a C-to-A transversion at
position
12258. It is thought that this mutation alters a highly conserved basepair in
the
acceptor stem of the tRNA(Ser) molecule, which would affect aminoacylation of
the
tRNA thereby altering the function of the tRNA for serine and reducing the
accuracy
of mitochondrial translation.
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[0216] Other mutations in the same gene cause MELAS/MERRF Overlap
Syndrome. One such mutation is a heteroplasmic 12207G-A transition in the MT-
TS2 gene. Upon examination, skeletal muscle biopsies revealed ragged red
fibers,
significant pleomorphic mitochondrial proliferation, and complex I deficiency.
The
12207G-A mutation occurs in a region involved in the formation of the acceptor
stem
of the tRNA molecule. Individuals with MELAS/MERRF Overlap Syndrome
experience a combination of the signs and symptoms of both disorders as
described
above.
Cytochrome c Oxidase Deficiency
[0217] Cytochrome c oxidase (COX) deficiency is a mitochondrial disorder
caused
by a lack of COX. Cytochrome c oxidase, also known as complex IV, is the
terminal
enzyme of the mitochondrial respiratory chain located within the mitochondrial
inner
membrane. Complex IV is composed of 13 polypeptides. Subunits I, II, and III
(MTC01, MTCO2, and MTC03) are encoded by mtDNA, while subunits IV, Va, Vb,
VIa, VIb, VIc, VIIa, VIIb, Vile, and VIII are nuclear encoded. Because COX is
encoded by both nuclear and mitochondrial genes, COX deficiency can be
inherited in
either an autosomal recessive or maternal pattern. A G-to-A transition at
nucleotide
6480 of the MTC01 gene, which encodes cytochrome c oxidase subunit I, is
associated with sensorineural hearing loss, ataxia, myoclonic epilepsy, and
mental
retardation. The signs and symptoms of COX deficiency typically manifest
before
two years of age, but can appear later in mildly affected individuals.
[0218] Another form of cytochrome c oxidase deficiency results from mutations
in
the MTCO2 gene, which encodes cytochrome c oxidase subunit II. A T-to-C
transition at nucleotide 7587 of the MT-0O2 gene is associated with ataxia,
distal
weakness, retinopathy, and optic atrophy.
Recessive ataxia syndromes
1. Infantile Cerebellar-retinal Degeneration
[0219] Infantile cerebellar-retinal degeneration (ICRD), also known as
mitochondrial aconitase deficiency, is associated with a Ser112Arg mutation in
the
nuclear ACO2 gene, which encodes mitochondrial aconitase. Aconitase catalyzes
the
isomerization of citrate to isocitrate via cis-aconitate in the second step of
the TCA
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cycle. ICRD is a severe autosomal recessive neurodegenerative disorder
characterized by onset between two and six months of age of truncal hypotonia,
athetosis, seizures, and ophthalmologic abnormalities, including optic atrophy
and
retinal degeneration. Individuals with ICRD exhibit profound psychomotor
retardation and progressive cerebral and cerebellar degeneration.
2. Charlevoix-Saguenay Spastic Ataxia
[0220] Charlevoix-Saguenay spastic ataxia, also known as autosomal recessive
spastic ataxia of Charlevoix-Saguenay (ARSACS), is caused by a homozygous or
compound heterozygous mutation in the SACS gene encoding the sacsin protein.
Research suggests that sacsin may interact with the heat shock protein 70
(Hsp70)
chaperone machinery, which plays an important role in protein folding and the
cellular response to aggregation-prone mutant proteins associated with
neurodegenerative diseases. Mutations in the SACS gene lead to the production
of
unstable sacsin protein that fails to function normally. ARSACS is a complex
neurodegenerative disorder characterized by the progressive degeneration of
the
cerebellum and spinal cord and early childhood onset of cerebellar ataxia,
pyramidal
tract signs, peripheral neuropathy, retinal changes, and, in some cases,
cognitive
decline.
3. Primary Coenzyme Q10 Deficiency-1
[0221] Primary coenzyme Q10 deficiency-1 (C0Q10D1) is an autosomal recessive
disorder caused by a homozygous or compound heterozygous mutation in the COQ2
gene, which encodes COQ2, or parahydroxybenzoic-polyprenyltransferase. COQ2
catalyzes one of the final reactions in the biosynthesis of CoQ10, the
prenylation of
parahydroxybenzoate with an all-trans polyprenyl group. Coenzyme Q10 (CoQ10),
or ubiquinone, functions as an electron carrier critical for electron transfer
by the
mitochondrial inner membrane respiratory chain, and is a lipid-soluble
antioxidant.
Primary CoQ10 deficiency-1 disorder is associated with five major phenotypes,
including: an encephalomyopathic form with seizures and ataxia; a multisystem
infantile form with encephalopathy, cardiomyopathy and renal failure; a
predominantly cerebellar form with ataxia and cerebellar atrophy; Leigh
Syndrome
with grown retardation; and an isolated myopathic form.
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4. Ataxia with Oculomotor Apraxia Type 1
[0222] Ataxia with oculomotor apraxia (AOA) comprises a group of autosomal
recessive disorders characterized by ataxia, oculomotor apraxia, and
choreoathetosis.
AOA includes ataxia telangiectasia (AT), ataxia telangiectasia like disorder
(ATLD),
ataxia oculomotor apraxia type 1 (A0A1), and ataxia oculomotor apraxia type 2
(A0A2). A0A1, also known as ataxia, early-onset, with oculomotor apraxia and
hypoalbumineria, is characterized by early-onset cerebellar ataxia, oculomotor
apraxia, hypoalbumineria, hypercholesterolemia, and late axonal sensorimotor
neuropathy. A0A1 is caused by mutations in the APTX gene, which encodes
aprataxin, a member of the histidine triad (HIT) superfamily, members of which
have
nucleotide-binding and diadenosine polyphosphate hydrolase activities.
Aprataxin is
a DNA-binding protein involved in single-strand DNA break repair, double-
strand
DNA break repair, and base excision repair. Mutations in APTX result in the
production of an unstable aprataxin protein that is quickly degraded in the
cell.
Nonfunctional aprataxin leads to an accumulation of breaks in DNA,
particularly in
the neurocytes of the cerebellum where DNA repair is critical.
5. Autosomal Recessive Spinocerebellar Ataxia-9
[0223] Autosomal recessive spinocerebellar ataxia-9 (SCAR9), also known as
coenzyme Q10 deficiency-4 (C0Q10D4), is an autosomal recessive disorder caused
by homozygous or compound heterozygous mutations in the COQ8 gene. SCAR9 is
characterized by childhood-onset of cerebellar ataxia and exercise
intolerance.
Patients manifest gait ataxia, cerebellar atrophy with slow progression.
Additional
features include variable seizures, mild mental impairment, brisk tendon
reflexes, and
Hoffmann sign.
6. Ataxia, Pyramidal Syndrome, and Cytochrome Oxidase Deficiency
[0224] A homozygous missense mutation in COX20, also known as FAM36A,
causes impaired cytochrome c oxidase assembly and is associated with ataxia
and
muscle hyptonia. Additional clinical symptoms include oligohydramnios and
growth
retardation during pregnancy, low birth weight, delayed speech development,
pyramidal signs, short stature, mildly elevated serum and cerebrospinal fluid
lactate
levels, and myocyte complex IV deficiency. The mutation has been identified as
a
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homozygous c.154A-C transversion in exon 2 of the COX20 gene, resulting in a
T52P
substitution at a highly conserved residue at the interface between the inner-
membrane embedded region and the predicted mitochondrial matrix-localized loop
fragment. The COX2 gene encodes cytochrome c oxidase protein 20, which plays a
role in the assembly of mitochondrial complex IV and interacts with cytochrome
c
oxidase subunit II.
7. Friedreich's Ataxia
[0225] Friedreich's ataxia is an autosomal recessive neurodegenerative
disorder
caused by a mutation in the FXN gene, which encodes frataxin. Frataxin is a
nuclear-
encoded mitochondrial iron chaperone that is localized to the inner
mitochondrial
membrane and involved in iron-sulfur biogenesis and heme biosynthesis. The
most
common molecular abnormality is a GAA trinucleotide repeat expansion in intron
1
of the FXN gene. Whereas normal individual have 5 to 30 GAA repeat expansions,
individuals affected with Friedreich's ataxia have from 70 to more than 1,000
GAA
triplets.
[0226] Friedreich's ataxia is characterized by progressive gait and limb
ataxia with
associated limb muscle weakness, absent lower limb reflexes, extensor plantar
responses, dysarthria, and decreased vibratory sense and proprioception. Other
features include visual defects, scoliosis, pes cavus, and eardiomyopathy.
Onset
typically occurs in the first or second decade. Affected individuals who
develop
Friedreich's ataxia between ages 26 and 39 are considered to have late-onset
Friedreich's ataxia (LOFA). When the signs and symptoms begin after age 40 the
condition is called very late-onset Friedreich's ataxia (VLOFA). LOFA and
VLOFA
usually progress more slowly than typical Friedreich's ataxia.
8. Infantile Onset Spinocerebellar Ataxia
[0227] Infantile onset spinocerebellar ataxia (IOSCA), also known as
Mitochondrial
DNA Depletion Syndrome-7, is an autosomal recessive severe neurodegenerative
disorder caused by a homozygous or compound heterozygous mutation in the
nuclear-
encoded ClOORF2 gene, which encodes the twinkle and twinky proteins. Twinkle
is
a mitochondrial protein involved in mtDNA metabolism. The ClOORF2 gene
mutations that cause IOSCA interfere with the function of twinkle resulting in
mtDNA depletion. IOSCA is associated with the following C100RF2 mutations:
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P83S/R463W; Y508C/A318T; Y508C/R29X; T451I/T4511; c.1460C-T
(T487I)/c.1485-1G-A; and 1472C-T.
[0228] IOSCA is characterized by hypotonia, ataxia, ophthalmoplegia, hearing
loss,
seizures, sensory axonal neuropathy, reduced mental capacity, and mtDNA
depletion
in the brain and liver. Individuals affected with IOSCA often develop
autonomic
nervous system disorders and experience excessive sweating, incontinence, and
constipation.
9. Leukoencephalopathy with Brain Stem and Spinal Cord Involvement and
Lactate Elevation
[0229] Leukoencephalopathy with brainstem and spinal cord involvement and
lactate elevation (LBSL) is an autosomal recessive disorder that can be caused
by
homozygous or compound heterozygous mutations in the gene encoding
mitochondrial aspartyl-tRNA synthetase (DARS2). The mutation results in
reduced
aspartyl-tRNA synthetase activity.
[0230] LBSL is defined by a highly characteristic constellation of
abnormalities
observed by magnetic resonance imaging and spectroscopy. These include a
pattern
of inhomogeneous cerebral white matter abnormalities, selective involvement of
brainstem and spinal tracts, and increased lactate in the abnormal white
matter.
Affected individuals develop slowly progressive cerebellar ataxia, spasticity,
and
dorsal column dysfunction, sometimes with a mild cognitive deficit or decline.
Onset
typically occurs between three and fifteen years of age.
10. Autosomal Recessive Spastic Ataxia-3
[0231] Autosomal recessive spastic ataxia-3 (SPAX3), also known as autosomal
recessive spastic ataxia with leukoencephalopathy (ARSAL), is caused by
homozygous or compound heterozygous complex genomic rearrangements involving
the MARS2 gene, which encodes mitochondrial methionyl-tRNA synthetase
(mtMetRS), a protein localized to the mitochondrial matrix. The protein shares
a high
degree of identity with methionyl-tRNA synthetases from other mammals.
Mutations
in MARS2 result in reduced protein levels. Some affected individuals have a
heterozygous 268-bp deletion in the MARS2 gene, resulting in a frameshift and
premature termination (c.681de1268bpfs236Ter). Other affected individuals have
duplications of the MARS2 gene.
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[0232] SPAX3 is a progressive disease characterized by ataxia, dysarthria,
horizontal nystagmus, spasticity, hyperreflexia, urinary urgency, scoliosis,
dystonia,
cognitive impairment, optic atrophy, cataract, hearing loss, cerebellar
atrophy, cortical
atrophy, leukoencephalopathy, and complex I deficiency. The disease usually
manifests between birth and fifty-nine years of age.
11. MIRAS and SANDO
[0233] Mitochondrial recessive ataxia syndrome (MIRAS) and sensory ataxia
neuropathy dysarthria and ophthalmoplegia (SANDO) are disorders that fall
under a
group of conditions known as the ataxia neuropathy spectrum. Ataxia neuropathy
spectrum is caused by mutations in the POLG gene, and, rarely, the C100RF2
gene.
The POLG gene encodes DNA polymerase gamma, which functions in the replication
of mitochondrial DNA. The POLG protein is composed of a C-terminal polymerase
domain and an amino-terminal exonuclease domain. The exonuclease domain
increases the fidelity of mitochondrial DNA replication by conferring a
proofreading
activity to the enzyme.
[0234] MIRAS is associated with W748S and E1143G cis, and homozygous W748S
or A467T POLG1 mutations. Clinical symptoms of MIRAS include ataxia,
polyneuropathy, reduced muscle strength, cramps, epilepsy, cognitive
impairment,
athetosis, tremor, obesity, eye movement disorders, cerebellar atrophy, white
matter
changes, muscle denervation, and, rarely, mitochondrial alterations. MIRAS
onset
typically occurs between five and thirty-eight years of age.
[0235] SANDO is commonly associated with a compound heterozygous or
homozygous A467T mutation. Other mutations associated with SANDO include
N468D, G517V, G737R, R1138C, and E1143G missense mutations. SANDO is a
progressive disease characterized by neuropathy causing sensory loss, variable
alterations in strength, ataxia, absent or reduced tendon reflexes, ptosis,
ophthalmoplegia, dysarthria, facial weakness, myoclonic epilepsy, and
depression.
Additional features include elevated serum and cerebrospinal fluid lactate
levels,
spinocerebellar and dorsal column tract degeneration, thalamic lesions,
cerebellar
atrophy or white matter changes, multiple mtDNA deletions, ragged red fibers,
loss of
myelinated and unmyelinated axons, posterior column atrophy, dorsal root
ganglia
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neuron loss, reduced mtDNA number in affected neurons, and reduced activity of
mitochondria! complexes I and IV.
12. Mitochondrial Spinocerebellar Ataxia and Epilepsy
[0236] Mitochondrial spinocerebellar ataxia and epilepsy (MSCAE) is a disorder
comprising spinocerebellar ataxia, peripheral neuropathy, and epilepsy. Onset
typically occurs during second and third decades and can be with ataxia or
epilepsy,
but all patients with MSCAE will develop ataxia if they survive, while only
approximately 80% will develop epilepsy. Other clinical features include
migraine,
myoclonus or myoclonic seizures, high T2 signal in the thalamus, occipital
cortex,
and cerebellum, cerebellar atrophy, enlarged olives, stroke-like lesions,
mtDNA
depletion in neurons, and progressively reduced complex I. Several POLG1
mutations are associated with this disorder, the most common being the c.1399G-
A
that gives p.A467T, the c.2243G-C giving the p.W748S, and the Gln497His
mutation.
13. Spastic Ataxia with Optic Atrophy
[0237] Spastic ataxia with optic atrophy (SPAX4) is a slowly progressive
autosomal
recessive neurodegenerative disease characterized by cerebellar ataxia,
spastic
paraparesis, dysarthria, and optic atrophy. SPAX4 is associated with mutations
affecting the MTPAP gene, resulting in a defect of mitochondrial mRNA
maturation.
One particular mutation is a homozygous N478D missense mutation. The MTPAP
gene encodes a polymerase that is a member of the DNA polymerase type-B-like
family. The enzyme synthesizes the 3' poly(A) tail of mitochondrial
transcripts and
plays a role in replication-dependent histone mRNA degradation. Affected
individuals exhibit decreased poly(A) tail length of mitochondrial transcripts
including those for COX1 and RNA14.
14. Mitochondrial Complex I Deficiency
[0238] Mitochondrial complex I deficiency (MT-C1D) is a disorder of the
mitochondrial respiratory chain associated with mutations in the NUBPL gene.
The
NUBPL gene encodes a member of the Mrp/NBP35 ATP-binding proteins family.
The encoded protein is required for the assembly of complex I (NADH
dehydrogenase), located in the mitochondrial inner membrane. MT-C1D is
characterized by a wide variety of clinical manifestations ranging from lethal
neonatal
disease to adult-onset neurodegenerative disorders including macrocephaly with
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progressive leukodystrophy, non-specific encephalopathy, cardiomyopathy,
myopathy, liver disease, Leigh Syndrome, LHON, and some forms of Parkinson's
disease.
15. Progressive External Ophthalmoplegia with Mitochondrial DNA Deletions
Autosomal Dominant Type 5
[0239] Progressive external ophthalmoplegia with mitochondrial DNA deletions
autosomal dominant type 5 (PEOA5) can be either an autosomal dominant or
recessive disorder caused by mutations in the nuclear-encoded RRM2B gene.
Recessive inheritance of PEOA5 is associated with homozygous or compound
heterozygous missense variations in the RRM2B gene. PEOA5 is characterized by
progressive weakness of ocular muscles and levator muscle of the upper eyelid.
In a
minority of cases, it is associated with skeletal myopathy, which
predominantly
involves axial or proximal muscles and which causes abnormal fatigability.
Ragged
red fibers and atrophy are found on muscle biopsy. Additional symptoms may
include cataracts, hearing loss, sensory axonal neuropathy, ataxia,
depression,
hypogonadism, and Parkinsonism.
16. Mitochondrial Complex III Deficiency Nuclear Type 2
[0240] Mitochondrial complex III deficiency nuclear type 2 (MC3DN2) is an
autosomal recessive severe neurodegenerative disorder caused by a homozygous
or
compound heterozygous mutation in the nuclear-encoded TTC19 gene. The TTC19
gene encodes tetratricopeptide repeat protein 19, a subunit of mitochondrial
respiratory chain complex III, which transfers electrons from coenzyme Q to
cytochrome c. This electron transfer contributes to the extrusion of protons
across the
inner mitochondrial membrane and contributes to the mitochondrial
electrochemical
potential. Mutations in the TTC19 gene include Leu219X and Gln173X nonsense
mutations.
[0241] MC3DN2 presents in childhood, but may show later onset, even in
adulthood. Affected individuals have motor disability, with ataxia, apraxia,
dystonia,
and dysarthria, associated with necrotic lesions throughout the brain. Most
patients
also have cognitive impairment and axonal neuropathy and become severely
disabled
later in life. The disorder may present clinically as spinocerebellar ataxia
or Leigh
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Syndrome, or with psychiatric disturbances. Complex III deficiency is observed
on
muscle biopsy.
17. Episodic Encephalopathy due to Thiamine Pyrophosphokinase Deficiency
[0242] Episodic encephalopathy due to thiamine pyrophosphokinase deficiency,
also known as Thiamine Metabolism Dysfunction Syndrome-5 (THMD5), is an
autosomal recessive thiamine metabolism disorder caused by a homozygous or
compound heterozygous mutation in the TPK1 gene. The TPK1 gene encodes
thiamine pyrophosphokinase (TPK), an enzyme involved in the regulation of
thiamine
metabolism. TPK catalyzes the conversion of thiamine, a form of vitamin Bl, to
thiamine pyrophosphate (TPP). Thymine pyrophosphate is an active cofactor for
enzymes involved in glycolysis and energy production, including transketolase,
pyruvate dehydrogenase, and alpha-ketoglutarate dehydrogenase.
[0243] Onset of episodic encephalopathy due to thiamine pyrophosphokinase
deficiency typically occurs between one and four years of age. Affected
individuals
present with a highly variable phenotype characterized by progressive
neurologic
dysfunction manifested as ataxia, dystonia, spasticity, inability to walk,
mildly
delayed developments, and increased serum and cerebrospinal fluid lactate
levels.
Other clinical features include exacerbated encephalopathy during an
infection,
hypotonia, microcephaly, epilepsy, and ophthalmoplegia.
Dominant Ataxia Syndromes
1. S_pinocerebellar Ataxia-28
[0244] Spinocerebellar ataxia-28 (SCA28) is an autosomal dominant disorder
caused by heterozygous mutation in the AFG3L2 gene. The AFG3L2 gene encodes
the AFG3-like protein 2 (AFG3L2), an ATP-dependent protease localized to the
mitochondrial inner membrane where it forms the catalytic subunit of the m-AAA
protease, which degrades misfolded proteins and regulates ribosome assembly.
Mutations associated with SCA28 include the following missense mutations:
N432T;
S674L; E691K; A694E; R702Q; and Y689H. 5CA28 is characterized by cerebellar
ataxia, dysarthria, nystagmus, ophthalmoparesis, ptosis, slow saccades,
hyperreflexia
in legs, extensor plantar response, leg and arm spasticity, myoclonic
epilepsy, and
cerebellar atrophy.
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2. Autosomal Dominant Cerebellar Ataxia, Deafness, and Narcolepsy
[0245] Autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-
DN) is caused by heterozygous mutation in the DNMT1 gene. The DNMT1 gene
encodes DNA (cytosine-5)-methyltransferases (DNMTs), such as DNMT1, which
maintain patterns of methylated cytosine residues in the mammalian genome.
Methylation patterns are responsible for the repression of parasitic sequence
elements
and the expression status of genes subject to genomic imprinting and X
inactivation.
Faithful maintenance of methylation patterns is required for normal mammalian
development, and aberrant methylation patterns are associated with certain
human
tumors and developmental abnormalities. Mutations of DNMT1 associated with the
development of ADCA-DN include the following missense mutations: A1a570Val;
Cys596Arg; and Va1606Phe.
[0246] ADCA-DN is characterized by adult onset of progressive cerebellar
ataxia,
narcolepsy/cataplexy, sensorineural deafness, and dementia. More variable
features
include optic atrophy, sensory neuropathy, psychosis, and depression.
Increased lipid
levels are observed on muscle biopsy.
3. Optic Atrophy-1
[0247] Optic atrophy-1 (OPA1) is an autosomal dominant optic atrophy caused by
heterozygous mutation in the OPA1 gene encoding a dynamin-like 120 kDa GTPase
that localizes to the inner mitochondrial membrane where it regulates cellular
processes including the stability of the mitochondrial network, mitochondrial
bioenergetics output, and the sequestration of pro-apoptotic cytochrome c
oxidase
molecules within the mitochondrial cristae spaces. OPA1 directly interacts
with
subunits of complexes I, II, and III, and an apoptosis inducing factor. Over
100
different OPA1 mutations have been identified, most of which are localized in
the
GTPase domain of the OPA1 protein. OPA1 mutations can cause oxidative
phosphorylation defects at the level of complex I, impairment in mitochondrial
ATP
synthesis driven by complex I substrates, fibroblasts which are more prone to
death,
and abnormal mitochondrial morphology.
[0248] OPA1 is characterized by an insidious onset of visual impairment in
early
childhood with moderate to severe loss of visual acuity, temporal optic disc
pallor,
color vision deficits, and centrocecal scotoma of variable density. Some
patients with
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mutations in the OPA1 gene may also develop extraocular neurologic features,
such
as deafness, progressive external ophthalmoplegia, muscle cramps,
hyperreflexia, and
ataxia.
Variable Ataxia Syndromes
1. CAPOS Syndrome
[0249] Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and
sensorineural
hearing loss (CAPOS) syndrome is a neurologic disorder associated with
heterozygous mutation in the ATP1A3 gene. The ATP1A3 gene encodes a Na+/K+
ATPase subunit ce.3, which forms a catalytic component of the active enzyme
that
catalyzes the hydrolysis of ATP coupled with the exchange of sodium and
potassium
ions across the plasma membrane.
[0250] CAPOS is characterized by early-childhood onset of recurrent episodes
of
acute ataxic encephalopathy associated with febrile illnesses. These acute
episodes
tend to decrease with time, but the neurologic sequelae are permanent and
progressive, resulting in gait and limb ataxia and areflexia. Affected
individuals also
develop progressive visual impairment due to optic atrophy and sensorineural
hearing
loss beginning in childhood. More variable features include abnormal eye
movements, pes cavus, and dysphagia.
2. Spinocerebellar Ataxia 7
[0251] Spinocerebellar ataxia 7 (SCA7) is caused by an expanded trinucleotide
repeat in the gene encoding ataxin-7 (ATXN7). The ATXN7 gene encodes ataxin 7,
a
transcription factor that appears to be critically important for chromatin
remodeling at
the level of histone acetylation and deubiquitination. SCA7 is a
neurodegenerative
disorder characterized by adult onset of progressive ataxia associated with
pigmental
macular dystrophy. Associated neurologic signs, such as ophthalmoplegia,
pyramidal
or extrapyramidal signs, deep sensory loss, or dementia, are also variable.
Barth Syndrome
[0252] Barth Syndrome is a heritable disorder of phospholipid metabolism
characterized by dilated cardiomyopathy (DCM), skeletal myopathy, neutropenia,
growth delay and organic aciduria. The prevalence of Barth Syndrome is
estimated at
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1/454,000 live births, with an estimated incidence ranging from 1/400,000 to
1/140,000 depending on geographic location. Barth Syndrome is an X-linked
disorder, and so disproportionately affects male patients.
[0253] Barth Syndrome is caused by mutations in the TAZ gene (tafazzin).
Defective TAZ1 function results in abnormal remodeling of cardiolipin and
compromises mitochondrial structure and respiratory chain function. TAZ1 is
expressed at high levels in cardiac and skeletal muscle and is involved in the
maintenance of the inner membrane of mitochondria. TAZ1 is involved in
maintaining levels of cardiolipin, which is essential for energy production in
the
mitochondria.
[0254] Clinical presentation of Barth Syndrome is highly variable. Most
subjects
develop DCM during the first decade of life, and typically during the first
year of life,
which may be accompanied by endocardial fibroelastosis (EFE) and/or left
ventricular
noncompaction (LVNC). The manifestations of Barth Syndrome may begin in utero,
causing cardiac failure, fetal hydrops and miscarriage or stillbirth during
the 2nd/3rd
trimester of pregnancy. Ventricular arrhythmia, especially during adolescence,
can
lead to sudden cardiac death. There is a significant risk of stroke. Skeletal
(mostly
proximal) myopathy causes delayed motor milestones, hypotonia, severe lethargy
or
exercise intolerance. There is a tendency to hypoglycemia during the neonatal
period.
Ninety percent of patients show mild to severe intermittent or persistent
neutropenia
with a risk of septicemia, severe bacterial sepsis, mouth ulcers and painful
gums.
Lactic acidosis and mild anemia may occur. Affected boys usually show delayed
puberty and growth delay that is observed until the late teens or early
twenties, when a
substantial growth spurt often occurs. Patients may also present severe
difficulties
with adequate food intake. Episodic diarrhea is common. Many patients have a
similar facial appearance with chubby cheeks, deep-set eyes and prominent
ears.
Skewed X chromosome inactivation is common in female carriers.
Biotinidase Deficiency
[0255] Biotinidase deficiency is an autosomal recessive metabolic disorder
associated with mutations in the BTD gene. In biotinidase deficiency, biotin
is not
released from proteins in the diet during digestion or from normal protein
turnover in
the cell. Biotinidase deficiency is associated with mutations in the BTD gene.
Biotin,
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also called vitamin B7, is an important water-soluble nutrient that aids in
the
metabolism of fats, carbohydrates, and proteins. Biotin deficiency can result
in
behavioral disorders, lack of coordination, learning disabilities and
seizures. Biotin
supplementation can alleviate and sometimes totally arrest such symptoms
Blindness
1. Gyrate Atrophy
[0256] Gyrate atrophy of the choroid and retina is caused by a homozygous or
compound heterozygous mutation in the OAT gene and is usually observed in
Finnish
families. Gyrate atrophy of the choroid and retina due to deficiency of
ornithine
aminotransferase typically begins in late childhood and is clinically
characterized by a
triad of progressive chorioretinal degeneration, early cataract formation, and
type II
muscle fiber atrophy. Characteristic chorioretinal atrophy with progressive
constriction of the visual fields leads to blindness at the latest during the
sixth decade
of life. Clinical symptoms include night-blindness, weakness, glutei atrophy,
scapular
winging, type 2 muscular atrophy, tubular aggregation, mental retardation,
hyperornithinemia, and white matter lesions.
2. Dominant Optic Atrophy
[0257] Dominant optic atrophy (DOA), also known as Kjer's optic neuropathy, is
an
autosomally inherited neuro-ophthalmic disease characterized by a bilateral
degeneration of the optic nerves, causing insidious visual loss, typically
starting
during the first decade of life. The disease affects primarily the retinal
ganglion cells
(RGC) and their axons forming the optic nerve, which transfer the visual
information
from the photoreceptors to the lateral geniculus in the brain. Vision loss in
DOA is
due to optic nerve fiber loss from mitochondria dysfunction. DOA patients
usually
suffer of moderate visual loss, associated with central or paracentral visual
field
deficits and color vision defects. The severity of the disease is highly
variable, the
visual acuity ranging from normal to legal blindness. An ophthalmic
examination of a
subject with DOA presents isolated optic disc pallor or atrophy, related to
the RGC
death. About 20% of DOA patients harbor extraocular multi-systemic features,
including neurosensory hearing loss, or less commonly chronic progressive
external
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ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like
illness,
spastic paraplegia or cataracts.
[0258] Two genes (OPA1, OPA3), which encode inner mitochondrial membrane
proteins, and three loci (OPA4, OPA5, OPA8) are known to cause DOA. All OPA
genes identified encode mitochondrial proteins embedded in the inner membrane
and
are ubiquitously expressed. OPA1 mutations affect mitochondrial fusion, energy
metabolism, control of apoptosis, calcium clearance and maintenance of
mitochondrial genome integrity. OPA3 mutations only affect the energy
metabolism
and the control of apoptosis. OPA1 is the major gene responsible for DOA.
[0259] In most cases, DOA presents as a non-syndromic, bilateral optic
neuropathy.
Although DOA is usually diagnosed in school-aged children complaining of
reading
problems, the condition can manifest later, during adult life. On fundus
examination,
the optic disk typically presents a bilateral and symmetrical pallor of its
temporal side
with the loss of RGC fibers entering the optic nerve. The optic nerve rim is
atrophic
and a temporal grey crescent is often present. Optic disc excavation may also
be
present. Optical Coherence Tomography (OCT) discloses the reduction of the
thickness of the peripapillary retinal nerve fiber layer in all four
quadrants, but does
not disclose alteration of other retinal layers. The visual field typically
shows a
cecocentral scotoma, and less frequently a central or paracentral scotoma,
while
peripheral visual field remains normal. Importantly, there is a specific
tritanopia, i.e.,
a blue-yellow axis of color confusion, which, when found, is strongly
indicative of
DOA. The pupillary reflex and circadian rhythms are not affected, suggesting
that the
melanopsin RGC are spared during the course of the disease.
[0260] In Syndromic Dominant Optic Atrophy and Deafness (Syndromic DOAD)
and Dominant Optic Atrophy plus (D0Aplus) patients experience full penetrance
and
usually more severe visual deficits. DOAD and DOAplus with extra-
ophthalmological abnormalities represent up to 20% of DOA patients with an
OPA1
mutation. The most common extra-ocular sign in DOA is sensorineural hearing
loss,
but other associated findings may occur later during life (e.g., myopathy and
peripheral neuropathy), suggesting that there is a continuum of clinical
presentations
ranging from a mild "pure DOA" affecting only the optic nerve to a severe and
multi-
systemic presentations. Sensorineural hearing loss associated to DOA may range
from severe and congenital to subclinical with intra- and inter- familial
variations, and
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mostly segregate with the OPA1 R445H (c.1334G>A) mutation. In general,
auditory
brain stem responses, which reflect the integrity of the auditory pathway from
the
auditory nerve to the inferior colliculus, are absent, but both ears show
normal evoked
otoacoustic emissions, reflecting the functionality of presynaptic elements
and in
particular that of the outer hair cells.
3. LHON
[0261] Leber's hereditary optic neuropathy (LHON) is a maternally inherited
blinding disease with variable penetrance. LHON is usually due to one of three
pathogenic mitochondrial DNA (mtDNA) point mutations. These mutations are at
nucleotide positions 11778 G to A, 3460 G to A and 14484 T to C, respectively
in the
MTND4, MTND1 and MTND6 subunit genes of complex I of the oxidative
phosphorylation chain in mitochondria. Reduced efficiency of ATP synthesis and
increased oxidative stress are believed to sensitize the retinal ganglion
cells to
apoptosis.
102621 Leber's hereditary optic neuropathy (LHON) is characterized by severe
visual loss, which usually does not manifest until young adulthood. Maternal
transmission is due to a mitochondrial DNA (mtDNA) mutation affecting
nucleotide
positions (nps) 11778/ND4, 14484/ ND6, or 3460/ND1. These three mutations,
affecting respiratory complex I, account for about 95% of LHON cases. Patients
inherit multicopy mtDNA entirely from the mother (via the oocyte). The
mitochondria may carry only wild-type or only LHON mutant mtDNA
(homoplasmy), or a mixture of mutant and wild-type mtDNA (heteroplasmy). Only
high loads of mutant heteroplasmy or, most frequently, homoplasmic mutant
mtDNA
in the target tissue put the subject at risk for blindness from LHON. Except
for
patients carrying the 14484/ND6 mutation (who present with a more benign
disease
course), most patients remain legally blind. Typically, a subject in his
second or third
decade of life will present with abrupt and profound loss of vision in one
eye,
followed weeks to months later by similar loss of vision in the other eye.
LHON may
occur later in life and affects both men and women. Environmental factors may
trigger the visual loss but do not fully explain why only certain individuals
within a
family become symptomatic. Additional symptoms include disc microangiopathy,
pseudo disc edema, vascular tortuosity, optic atrophy, cardiac conduction
defects,
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spastic paraparesis, sexual and urinary disturbances, Sudden Infant Death
Syndrome,
abnormal visual evoked potentials, spastic dystonia and encephalopathy.
[0263] Disruptions in ND4 can also lead to spastic paraparesis which is
associated
with leg stiffness, abnormal visual evoked potentials and sexual and urinary
disturbances.
4. Wolfram Syndrome 1
[0264] Wolfram Syndrome-1 (WFS1) is a rare and severe autosomal recessive
neurodegenerative disease caused by homozygous or compound heterozygous
mutations in the wolframin gene. Wolframin encodes an endoglycosidase H-
sensitive
glycoprotein that is expressed in the heart, brain, pancreas, liver, kidney,
skeletal
muscle, hippocampus CA1, amygdaloid areas, olfactory tubercle and allocortex.
WFS1 is characterized by diabetes mellitus, optic atrophy, diabetes insipidus,
and
deafness (DIDMOAD). Additional clinical features may include renal
abnormalities,
ataxia, Nystagmus, polyneuropathy, central respiratory failure, myoclonus,
seizures,
organic brain syndrome, dementia or mental retardation, urinary tract atony,
orthostatic hypotension, gastroparesis, and diverse psychiatric illnesses. The
minimal
diagnostic criteria for Wolfram Syndrome are optic atrophy and diabetes
mellitus of
juvenile onset. Hearing impairment in Wolfram Syndrome is typically
progressive
and mainly affects the higher frequencies, but a small fraction of affected
individuals
have congenital deafness.
[0265] Auto somal dominant mutations in the WFS1 gene have been found to cause
low-frequency nonsyndromic deafness as well as a Wolfram Syndrome-like
phenotype in which affected individuals have hearing impairment with diabetes
mellitus and/or optic atrophy.
[0266] Some cases of Wolfram Syndrome of early-onset diabetes mellitus, optic
atrophy, and deafness may have their basis in a mitochondrial mutation, such
as a 7.6-
kb heteroplasmic deletion of mtDNA extending from nucleotide 6466 to
nucleotide
14134, inclusive. Some patients exhibit mild hyperlactatemia or morphologic
and
biochemical abnormalities of the mitochondria. A high percentage of DIDMOAD
patients harbor so-called secondary LHON mutations, and both DIDMOAD and
LHON patients are concentrated in 2 different mitochondrial haplotypes defined
by
sets of polymorphisms in ND and tRNA genes. Thus, the different clinical
features of
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the mitochondrial disease groups investigated correspond to different clusters
of
mtDNA variants, which might act as predisposing haplotypes, increasing the
risk for
the given disease.
5. Wolfram Syndrome 2
[0267] Wolfram Syndrome-2 (WFS2) is an autosomal recessive neurodegenerative
disorder caused by homozygous mutations in the CISD2 (ERIS) gene, which
encodes
CDGSH iron sulfur domain protein 2. CISD2 is an endoplasmic reticulum-
localized
zinc finger protein that is expressed in pancreas, brain and other tissues.
WFS2 is
characterized by diabetes mellitus, mild diabetes insipidus, high frequency
sensorineural hearing loss, optic atrophy or neuropathy, urinary tract
dilatation, and
defective platelet aggregation resulting in peptic ulcer bleeding.
6. Age-related Macular Degeneration
[0268] Age-related macular degeneration (ARMD) is a common complex disorder
that affects the central region of the retina and is the leading cause of
blindness in
Caucasian Americans over 65 years of age. Susceptibility to ARMD is associated
with mutations in the ARMS2 gene, which encodes a deduced 107-amino acid
protein
with nine predicted phosphorylation sites and a molecular mass of 12 kD. The
ARMS2 protein is localized to the mitochondrial outer membrane.
Brunner Syndrome
[0269] Brunner Syndrome is a form of X-linked non-dysmorphic mild mental
retardation. Two monoamine oxidase isoenzymes, monoamine oxidase A (MAOA)
and monoamine oxidase B (MAOB), are closely linked in opposite orientation on
the
X chromosome and are expressed in the outer mitochondrial membrane. MAOA and
MAOB oxidize neurotransmitters and dietary amines, the regulation of which is
important to the maintenance of normal mental states. MAOA prefers the
monoamines serotonin, norepinephrine, and dopamine as substrates, while MAOB
prefers phenylethylamine. Brunner Syndrome is caused by an MAOA deficiency,
which results in an accumulation of serotonin, dopamine, and epinephrine, in
the
brain. Mutations in the MAOA gene have been associated with aggressive,
violent,
impulsive, autistic, and antisocial behaviors.
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Cardiomyopathy
1. Left Ventricular Noncompaction
[0270] Left ventricular noncompaction-1 (LVNC1) is caused by a heterozygous
mutation in the alpha-dystrobrevin gene and is characterized by numerous
prominent
trabeculations and deep intertrabecular recesses in hypertrophied and
hypokinetic
segments of the left ventricle.
[0271] The developing myocardium gradually condenses, and the large spaces
within the trabecular meshwork flatten or disappear. Isolated noncompaction of
ventricular myocardium, sometimes called spongy myocardium or persisting
myocardial sinusoids, represents an arrest in endomyocardial morphogenesis,
and is
characterized by numerous, excessively prominent trabeculations and deep
intertrabecular recesses. LVNC may occur in isolation or in association with
congenital heart disease. Distinctive morphologic features can be recognized
on 2-
dimensional echocardiography. Clinical manifestations of the disorder included
depressed left ventricular systolic function, ventricular arrhythmias,
systemic
embolization, and distinctive facial dysmorphism.
[0272] The clinical presentation of left ventricular noncompaction is highly
variable, ranging from asymptomatic to severe heart failure and sudden death.
Higher
occurrence of familial cases, facial dysmorphism, and congenital arrhythmias
such as
Wolff-Parkinson-White Syndrome are observed in children, whereas secondary
arrhythmias, such as atrial fibrillation, are more common in adults. The mode
of
inheritance is predominantly autosomal dominant, and sarcomere protein
mutations
are more common in adults.
2. Infantile Histiocytoid Cardiornyopathy
[0273] Histiocytoid cardiomyopathy goes by various names, including infantile
xanthomatous cardiomyopathy, focal lipid cardiomyopathy, oncocytic
cardiomyopathy, infantile cardiomyopathy with histiocytoid change, and foamy
myocardial transformation of infancy. The disorder is caused by mutations in
the
gene encoding mitochondrial cytochrome b (MTCYB) and is a rare but distinctive
entity of infancy and childhood characterized by the presence of
characteristic pale
granular foamy histiocyte-like cells within the myocardium. It usually affects
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children younger than 2 years of age, with a clear predominance of females
over
males. Infants present with dysrhythmia or cardiac arrest, and the clinical
course is
usually fulminant, sometimes simulating Sudden Infant Death Syndrome. Clinical
features include high frequency of anomalies involving the nervous system and
eyes
and of oncocytic cells in various glands. Because of the large number of
mitochondria present in the histiocytoid cells, they resemble oncocytes. Other
disorders involving MTCYB mutations include exercise intolerance, myopathy,
LHON, Familial Myalgia Syndrome, colorectal cancer, encephalomyopathy,
Parkinsonism, and susceptibility to obesity.
3. Cardioencephalomyopathy with Cytochrome c Oxidase Deficiency
(CEMCOX1)
[0274] Fatal infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX) deficiency-1 (CEMCOX1) can be caused by a compound heterozygous
mutation in the SCO2 gene, a COX assembly gene on chromosome 22q13. Another
form of fatal infantile cardioencephalomyopathy due to COX deficiency, CEMCOX2
is caused by mutations in the COX15 gene on chromosome 10q24. Age of onset for
infantile cardioencephalomyopathy is usually within the first 3 months of
infancy and
is equally prevalent between males and females. Infants usually die at 6
months.
[0275] Infants with COX deficiency caused by a mutation in the SCO2 gene
present
with a fatal infantile cardioencephalomyopathy characterized by hypertrophic
cardiomyopathy, lactic acidosis, and gliosis. Heart and skeletal muscle show
reductions in COX activity, whereas liver and fibroblasts show mild COX
deficiencies. Patients show a severe reduction of the mitochondrial-encoded
COX I
and II subunits, whereas the nuclear-encoded COX subunits IV and Va are
present but
reduced in intensity. Clinical features include hypotonia, limb spasticity,
muscle
atrophy or denervation, respiratory difficulties, increased blood and CSF
lactate,
hypertrophic cardiomyopathy, seizures, psychomotor retardation, Leigh-like
Syndrome, neutropenia, ptosis, gliosis, ophthalmoplegia, encephalopathy, and
severely reduced COX activity.
4. Sengers Syndrome: Cardiomyopathy, Hypertrophic & Cataracts
[0276] Sengers Syndrome, also known as cardiomyopathic mitochondrial DNA
depletion syndrome-10 (MTDPS10), is caused by a homozygous or compound
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heterozygous mutation in the AGK gene. Sengers Syndrome is an autosomal
recessive mitochondrial disorder characterized by congenital cataracts,
hypertrophic
cardiomyopathy, skeletal myopathy, exercise intolerance, and lactic acidosis.
Mental
development is normal, but affected individuals may die early from
cardiomyopathy.
Skeletal muscle biopsies of affected individuals show severe mtDNA depletion.
[0277] While several pieces of evidence pointed indirectly to the involvement
of
oxygen free radicals in the etiology of cardiomyopathy with cataracts, direct
evidence
showed that complex I deficiency is associated with an excessive production of
hydroxyl radicals and lipid peroxidation. Patients with isolated
NADH:ubiquinone
oxidoreductase deficiency (or complex I deficiency) most commonly present with
fatal neonatal lactic acidosis or with Leigh disease. Although the clinical
features of
Sengers Syndrome suggest a mitochondrial disorder, no abnormalities are found
on
routine mitochondrial biochemical diagnostics, viz., the determination of
pyruvate
oxidation rates and enzyme measurements. Protein content of mitochondrial ANTI
is
strongly reduced in the muscle tissues of affected patients with Sengers
Syndrome.
Additional clinical phenotypes for cardiomyopathy with cataracts include
hepatopathy, tubulopathy, hypotonia, and mild developmental delay.
5. Cardiofaciocutaneous Syndrome 1 (CFC11
[0278] Cardiofaciocutaneous Syndrome-1 (CFC1), caused by disruptions in the
BRAF gene, is a multiple congenital anomaly disorder characterized by a
distinctive
facial appearance, heart defects, and mental retardation. The heart defects
include
pulmonic stenosis, atrial septal defect, and hypertrophic cardiomyopathy. Some
patients have ectodermal abnormalities such as sparse and friable hair,
hyperkeratotic
skin lesions, and a generalized ichthyosis-like condition. Typical facial
characteristics
include high forehead with bitemporal constriction, hypoplastic supraorbital
ridges,
downslanting palpebral fissures, a depressed nasal bridge, and posteriorly
angulated
ears with prominent helices. Most cases occur sporadically, but autosomal
dominant
transmission has been rarely reported.
[0279] Disruptions in BRAF gene function may impact the TCA cycle and
oxidative metabolism. Clinical features include atopic dermatitis, ichthyosis,
hyperkeratosis (extensor surfaces), keratosis pilaris, multiple palmar
creases, multiple
lentigines, sparse hair growth, optic nerve dysplasia, increased tendon
reflexes,
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extensor plantar response, increased sensitivity to light touch, mental
retardation,
seizures, cortical atrophy, hypoplasia, ptosis, strabismus, oculomotor
apraxia,
nystagmus, hypertelorism, exophthalmos, prominent philtrum, micrognathia,
macrocephaly, joint hyperextensibility, osteopenia, clinodactyly, pectus
excavatum or
carinatum, short stature, GI dysmotility, splenomegaly, enlarged mitochondria,
increased frequency of 2C fibers, reduced C0Q10, ventriculomegaly,
hypsarrhythmia;
and focal epileptiform discharges.
6. Trifunctional Protein Deficiency
[0280] Mitochondrial trifunctional protein (MTP) deficiency can be caused by
mutations in the genes encoding either the alpha (HADHA) or beta (HADHB)
subunits of the mitochondrial trifunctional protein. The mitochondrial
trifunctional
protein, composed of 4 alpha and 4 beta subunits, catalyzes 3 steps in
mitochondrial
beta-oxidation of fatty acids: long-chain 3-hydroxyacyl-CoA dehydrogenase
(LCHAD), long-chain enoyl-CoA hydratase, and long-chain thiolase activities.
Trifunctional protein deficiency is characterized by decreased activity of all
3
enzymes. Clinically, classic trifunctional protein deficiency can be
classified into 3
main clinical phenotypes: neonatal onset of a severe, lethal condition
resulting in
sudden unexplained infant death (SIDS), infantile onset of a hepatic Reye-like
syndrome, and late-adolescent onset of primarily a skeletal myopathy.
[0281] Some patients with MTP deficiency show a protracted progressive course
associated with myopathy, recurrent rhabdomyolysis, and sensorimotor axonal
neuropathy. These patients tend to survive into adolescence and adulthood.
Clinical
features include cardiomyopathy, myopathy, liver dysfunction, encephalopathy,
Sudden Infant Death Syndrome, and axonal neuropathy. Variant syndromes
comprising MTP mutations include hepatic with recurrent Hypoketotic
hypoglycemia,
later-onset axonal sensory neuropathy episodic myoglobinuria, and early-
onset
axonal sensory neuropathy.
7. Encephalocardiomyopathy with Cytochrome c Oxidase Deficiency
[0282] Mutations in the nuclear gene C120RF62 have been associated with fatal
infantile encephalocardiomyopathy with cytochrome c oxidase deficiency.
C120RF62 is a membrane-associated protein that localizes to the mitochondria
and
promotes COX I assembly & coupling with assembly of nascent subunits into COX
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holoenzyme complex. Clinical symptoms include reduced COX activity, neonatal
lactic acidosis, oligoamnios, septum-lucidum cysts, hypotelorism,
microphthalmia,
ogival palate, single palmar crease, hypertrophic cardiomyopathy,
hepatomegaly,
renal hypoplasia, adrenal hyperplasia, brain hypertrophy, white-matter
myelination,
and cavities in parieto-occipital region, brainstem, and cerebellum.
8. Cardiomyopathy + Encephalopathy
[0283] Mutations in NADH-Ubiquinone oxidoreductase Fe-S Protein 2 (NDUFS2)
have been associated with cardiomyopathy + encephalomyopathy. NDUFS2 is a
component of complex I and plays a role in protein transport. The age of onset
for the
disorder is from birth to 7 months. Infants usually die before 2 to 3 years of
age.
Clinical symptoms include axial hypotonia, failure to thrive, hypertrophic
cardiomyopathy, limb hyperrefiexia, optic atrophy, nystagmus, progressive
encephalopathy, sleep apnea, high lactate levels in CSF & blood, hypodensities
in
basal ganglia; generalized brain atrophy, and reduced complex I activity.
9. Mitochondrial Phosphate Carrier Deficiency
[0284] Mitochondrial phosphate carrier deficiency can be caused by disruptions
in
5LC25A3, which encodes a mitochondrial solute carrier. SLC25A3 aids in the
import
of inorganic phosphate into mitochondrial matrix and functions in ATP
synthesis.
Mitochondrial phosphate carrier deficiency is characterized by progressive
hypertrophic cardiomyopathy, respiratory failure, hypotonia, high serum
lactate, lipid
accumulation in type I muscle fibers, abnormal mitochondrial network,
defective ATP
synthesis and reduced mitochondrial phosphate carrier activity. Some infants
die in
the 1st year, whereas those that survive to adulthood exhibit exercise
intolerance and
proximal weakness.
10. Fatal infantile Cardioencephalomyopathy, due to Cytochrome c Oxidase
Deficiency 2 (CEMCOX2)
[0285] Fatal infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX) deficiency (CEMCOX2) can be caused by a compound heterozygous mutation
in the COX15 gene. Shortly afterbirth, patients present with seizures,
hypotonia, and
lactic acidosis. Other clinical symptoms include midface hypoplasia,
biventricular
hypertrophic cardiomyopathy and reduced Complex IV activity. Patients usually
die
within 1 month of life.
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11. Leigh Syndrome
[0286] Leigh Syndrome mutations have been identified in both nuclear- and
mitochondrial-encoded genes involved in energy metabolism, including
mitochondrial
respiratory chain complexes I, II, III, IV, and V, which are involved in
oxidative
phosphorylation and the generation of ATP, and components of the pyruvate
dehydrogenase complex.
[0287] Mutations in complex I genes include mitochondrial-encoded MTND2,
MTND3, MTND5, and MTND6, the nuclear-encoded NDUFS1, NDUFS3, NDUFS4,
NDUFS7, NDUFS8, NDUFA2, NDUFA9, NDUFA10, NDUFA12, NDUFAF6,
FOXRED1, COXPD15 and C200RF7, and the complex I assembly factor
NDUFAF2. A mutation in the MTFMT gene, which is involved in mitochondrial
translation, has also been reported with complex I deficiency.
[0288] Leigh Syndrome is also associated with mutations in complex I
(C80RF38),
complex II (the flavoprotein subunit A (SDHA)); complex III (BCS1L); complex
IV
(MTC03, COX10, COX15, SCO2, SURF1, TAC01, and PET100); complex V
(MTATP6); mitochondrial tRNA proteins (MTTV, MTTS2, MTTK, MTTW, and
MTTL1); components of the pyruvate dehydrogenase complex (e.g., DLD and
PDHA1); the LRPPRC gene; and coenzyme Q10.
[0289] Leigh Syndrome is an early-onset progressive neurodegenerative disorder
with a characteristic neuropathology consisting of focal, bilateral lesions in
one or
more areas of the central nervous system, including the brainstem, thalamus,
basal
ganglia, cerebellum, and spinal cord. Age of onset is around 1 year and
patients
usually die within 2 years of onset. The lesions are areas of demyelination,
gliosis,
necrosis, spongiosis, or capillary proliferation. Clinical features also
include
hypotonia, ataxia, vomiting, choreoathetosis, hyperventilation,
encephalopathy, loss
verbal milestones, motor spasticity, abnormal breathing rhythm, hearing loss,
nystagmus, dystonia, visual loss, ophthalmoparesis, optic atrophy, peripheral
neuropathy, intercurrent infection, cog-wheel rigidity, distal renal tubular
acidosis,
limb athetosis, seizures, carbohydrate intolerance, COX deficiency in muscle,
lactic
acidosis with hypoglycemia, kyphoscoliosis, short stature, brisk tendon
reflexes,
obesity, and high lactate levels in CSF. Clinical symptoms depend on which
areas of
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the central nervous system are involved. The most common underlying cause is a
defect in oxidative phosphorylation.
[0290] Mutations in NDUFV2, MTND2, MTND5, and MTND6 can result in Leigh
Syndrome due to mitochondrial complex I deficiency. Clinical symptoms include
reduced Complex I activity, hypertrophic cardiomyopathy, developmental delay,
cerebral atrophy, hypoplasia of the corpus callosum, acidosis, seizures, coma,
cardiovascular arrest, demyelinization of corticospinal tracts, subacute
necrotizing
encephalomyelopathy, progressive encephalopathy, respiratory failure, exercise
intolerance, weakness, mitochondrial proliferation in muscle, motor
retardation,
hypotonia, deafness, dystonia, pyramidal features, brainstem events with
oculomotor
palsies, strabismus & recurrent apnea, lactic acidemia, and basal ganglia
lesions.
[0291] Mutations in MTCO3 can result in Leigh Syndrome that usually presents
at 4
years of age. Clinical symptoms include spastic paraparesis with
ophthalmoplegia,
high serum lactic acid, Leigh-like lesions in putamen, and reduced COX
activity in
muscle. Mutations also found in MTCO3 cause LHON, Myopathy with exercise
intolerance, rhabdomyolysis, episodic encephalopathy, and nonarteritic
ischemic optic
neuropathy (NAION)-Myoclonic epilepsy.
[0292] Mutations in 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) results in 0-
Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency, a Leigh-like Syndrome that
usually manifests at neonatal to 6 months of age. Symptoms include hypotonia,
regression, poor feeding, dystonia, ataxia, seizures, dysmorphic facies,
vertebral
anomalies, tetralogy of fallot, progressive or acute encephalopathy,
respiratory chain
deficiencies, high CSF lactate, basal ganglia abnormalities, brain agenesis
and
accumulation of metabolites (e.g., methacrylyl-CoA, acryloyl-CoA, hydroxy-C4-
carnitine).
[0293] Mutations in enoyl-CoA hydratase, short-chain, 1 (ECHS1) results in
Short
chain enoyl-CoA hydratase (ECHS1) deficiency, a Leigh-like Syndrome that
presents
at the neonatal stage. ECHS1 catalyzes the second step in mitochondrial fatty
acid 13-
oxidation. Clinical symptoms include hypotonia, respiratory insufficiency or
apnea,
bradycardia, developmental delay, high serum lactate, white matter atrophy,
and
accumulation of metabolites (e.g., methacrylyl-CoA, acryloyl-CoA).
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[0294] Mutations in ATP synthase 6 (MTATP6) result in Maternal Inheritance
Leigh Syndrome (MILS). Clinical symptoms include hypotonia, developmental
delay, peripheral neuropathy, seizures, retinitis pigmentosa or optic atrophy,
ataxia,
respiratory failure, bilateral striatal necrosis, hereditary spastic
paraparesis,
myelopathy, limb spasticity, weakness, and sensory loss or pain.
12. Dilated Cardiomyopathy with Ataxia (DCMA)
[0295] 3-methylglutaconic aciduria type V (MGCA5), also called dilated
cardiomyopathy with ataxia (DCMA), is caused by a homozygous mutation in the
DNAJC19 gene on chromosome 3q26. DNAJC19 encodes a DNAJ domain-
containing protein that is localized to the inner mitochondrial membrane (TIM)
and
may be involved in molecular chaperone systems of Hsp70/Hsp40 type.
Mitochondrial import inner membrane translocase subunit TIM14 may also act as
a
co-chaperone that stimulates the ATP-dependent activity.
[0296] DCMA is an autosomal recessive disorder characterized by the onset of
dilated or noncompaction cardiomyopathy in infancy or early childhood.
Clinical
symptoms include cardiomyopathy, long Q-T syndrome, cerebellar ataxia, delayed
psychomotor development, optic atrophy, mental retardation, seizures,
testicular
dysgenesis, cryptorchidism to severe perineal hypospadias, growth retardation,
microcytic anemia, mild muscle weakness, mildly elevated hepatic enzymes and
increased urinary excretion of 3-methylglutaconic acid.
13. Mitochondrial DNA Depletion Syndrome 12 (Cardiomyopathic type)
[0297] Mitochondrial DNA Depletion Syndrome-12 (MTDPS12) is caused by
homozygous mutations in the Adenine nucleotide translocator 1 (ANTI) gene.
Heterozygous mutations in the ANTI gene cause autosomal dominant progressive
external ophthalmoplegia-2 (PEOA2).
[0298] Mitochondrial DNA Depletion Syndrome-12 is an autosomal recessive
mitochondrial disorder characterized by childhood onset of slowly progressive
hypertrophic cardiomyopathy and generalized skeletal myopathy resulting in
exercise
intolerance and, in some patients, muscle weakness, pain and atrophy. Skeletal
muscle biopsy shows ragged red fibers, mtDNA depletion, and accumulation of
abnormal mitochondria. Clinical symptoms include headache episodes, nausea,
vomiting, moderately high levels of creatine kinase in serum, ankle
contractures,
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lactic acidosis, hyperalaninemia, SDH-positive muscle fibers, multiple mtDNA
deletions or depletions, abnormal mitochondria containing paracrystalline
inclusions,
high citrate synthase levels, partial reductions in complexes I, III, IV and
V,
cardiomyocyte degeneration, subendocardial interstitial fibrosis, and
arteriolar smooth
muscle hypertrophy.
14. Cardiomyopathy due to Mitochondrial tRNA Deficiencies
[0299] Mutations in mtRNA Ile (MTTI) can result in fatal infantile onset
cardiomyopathy. Clinical features of other mtRNA Ile syndromes include cardiac
dilation and hypertrophy, short stature, deafness, some MELAS symptoms, death
due
to cardiac failure, low mitochondrial oxidative enzymes, familial progressive
necrotizing encephalopathy, impaired glucose tolerance, hyperlipidemia,
hyperuricemia, progressive myoelonus epilepsy, ragged red fibers, spastic
paraparesis,
ataxia; PEO; mental retardation, diabetes mellitus, hypomagnesemia,
hypokalemia,
hypertension, hypercholesterolemia, increased prevalence of migraine headache,
and
rhabdomyolysis.
[0300] Mutations in mtRNA Lys can result in neonatal hypertrophic
cardiomyopathy, diabetes, MERRF, high lactate and pyruvate levels in serum and
infantile death.
[0301] Mutations in mtRNA Leu (MTTL1) can result in hypertrophic
cardiomyopathy Barth-like Syndrome, diabetes, dilated cardiomyopathy,
MERRF/KSS, MELAS, MERRF-like with diabetes, optic neuropathy & retinopathy,
left ventricular noncompaction, Wolff-Parkinson-White conduction defects,
Sudden
Infant death Syndrome, riboflavin sensitive myopathy, rhabdomyolysis, fatigue,
PEO,
and the like. Age of onset typically occurs between 24 to 40 years.
[0302] Mutations in mtRNA Leu (MTTL2) can result in adult onset
cardiomyopathy, myopathy, sideroblastic anemia, PEO, and encephalomyopathy.
[0303] Mutations in mtRNA His can result in adult onset dilated or
hypertrophic
cardiomyopathy, pigmentary retinopathy and sensorineural deafness.
[0304] Mutations in mtRNA Gly can result in exercise intolerance,
nonobstructive
hypertrophic cardiomyopathy (onset age: neonatal to childhood), Complex IV &
Complexes II + III deficiencies and sudden death.
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15. Cardiomyopathy: Mitochondrial ATP synthase (Complex V) Defects
[0305] Mutations in ATP synthase Fl complex assembly factor-2 (ATP 12), which
is required for Complex V biogenesis, can result in mitochondrial complex V
(ATP
synthase) deficiency nuclear type 1 (MC5DN1). The disorder manifests at birth
and
subjects exhibit low APGAR scores and birth weight. Biochemically, the
patients
show a generalized decrease in the content of ATP synthase complex which is
less
than 30% of normal as well as high plasma lactate levels. Most cases present
with
neonatal-onset hypotonia, lactic acidosis, hepatomegaly, hyperammonemia,
hypertrophic cardiomyopathy, facial dysmorphism, microcephaly, psychomotor and
mental retardation, and 3-methylglutaconic aciduria. Many patients die within
a few
months or years.
[0306] Mutations in mitochondrial ATP synthase 8 (MT-ATP8), a component of
Complex V, can also result in apical hypertrophic cardiomyopathy and
neuropathy.
The disorder manifests during infancy and is associated with delayed motor
development, gait and balance disorder, dysarthric speech, extensor plantar
response,
reduced tendon response, mild external ophthalmoplegia, exercise intolerance,
shortness of breath (dyspnea) during exercise, angina and apical left
ventricular
hypertrophy, neuropathy, reduced Complex V activity & assembly, high lactate
levels
in CSF and abnormal nerve conduction velocity in legs.
16. Mitochondrial Complex IV Deficiency
[0307] Complex IV (cytochrome c oxidase) is the terminal enzyme of the
respiratory chain and consists of 13 polypeptide subunits, 3 of which are
encoded by
mitochondrial DNA. The 3 mitochondrial encoded proteins in the cytochrome
oxidase complex are the actual catalytic subunits that carry out the electron
transport
function.
[0308] Cytochrome c oxidase deficiency can be caused by mutations in several
nuclear-encoded and mitochondrial-encoded genes. Mutations associated with the
disorder have been identified in several mitochondrial COX genes, MTC01,
MTCO2,
MTC03, as well as in mitochondrial tRNA (ser) (MTTS1) and tRNA (leu) (MTTL1).
Mutations in nuclear genes include those in COX10, COX6B1, SC01, FAS TKD2,
C20RF64 (COA5), COA6, C120RF62 (COX14), COX20, and APOPT1. COX
deficiency caused by mutations in SCO2 and COX15 have been found to be
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associated with fatal infantile cardioencephalomyopathy. Cytochrome c oxidase
deficiency associated with Leigh Syndrome may be caused by mutations in the
SURF1 gene, COX15 gene, TAC01 gene, or PET100 gene. Cytochrome c oxidase
deficiency associated with the French Canadian type of Leigh Syndrome (LSFC)
is
caused by mutations in the LRPPRC gene. Most isolated COX deficiencies are
inherited as autosomal recessive disorders caused by mutations in nuclear-
encoded
genes; mutations in the mtDNA-encoded COX subunit genes are relatively rare.
[0309] Clinical features associated with the disruption of COA5 function
include
hypertrophic restrictive cardiomyopathy, accumulation of lipid droplets in
muscle,
reduced Complex IV activity, and mitochondrial proliferation in muscle. Age of
onset occurs in less than 1 month or in utero.
[0310] Clinical features associated with the disruption of COA6 function
include
hypertrophic cardiomyopathy, reduced complexes I & IV in cardiac tissue, and
multiple respiratory chain defects. Age of onset occurs in less than 1 year.
17. Combined Oxidative Phosphorylation Deficiency 8 (COXPD8)
[0311] Combined oxidative phosphorylation deficiency-8 (COXPD8) is caused by a
homozygous or compound heterozygous mutation in the Alanyl-tRNA Synthetase 2
(AARS2) gene, which encodes an amino acid tRNA synthetase.
[0312] COXPD8 is an autosomal recessive disorder due to dysfunction of the
mitochondrial respiratory chain. The main clinical manifestation is a lethal
infantile
hypertrophic cardiomyopathy, but there may also be subtle skeletal muscle and
brain
involvement. Biochemical studies show combined respiratory chain complex
deficiencies in complexes I, III, and IV in cardiac muscle, skeletal muscle,
and brain.
The liver is not affected. Muscle cells are positive for both COX & SDH.
[0313] A variant AARS2 syndrome is progressive leukoencephalopathy with
ovarian failure (LKENP), an autosomal recessive neurodegenerative disorder
characterized by loss of motor and cognitive skills, usually with onset in
young
adulthood. Some patients may have a history of delayed motor development or
learning difficulties in early childhood. Neurologic decline is severe,
usually
resulting in gait difficulties, ataxia, spasticity, and cognitive decline and
dementia.
Most patients lose speech and become wheelchair-bound or bedridden. Brain MRI
shows progressive white matter signal abnormalities in the deep white matter.
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Affected females develop premature ovarian failure. Clinical features of LKENP
include COX deficiency, ataxia, cerebellar atrophy, spasticity, cognitive
decline,
delayed development, ovarian failure during the 3rd to 5th decade, loss of
motor
skills, speech & cognition by 5th decade, and abnormal cerebral white matter.
18. Combined Oxidative Phosphorylation Deficiency 10 (COXPD10)
[0314] Combined oxidative phosphorylation deficiency-10 (COXPD10) is caused
by homozygous or compound heterozygous mutations in the mitochondrial
translation
optimization 1 homolog (MT01) gene. MT01 is a mitochondrial-tRNA modifier that
is normally expressed in tissues with high metabolic rate, such as skeletal
muscle,
liver, and heart. COXPD10 is an autosomal recessive disorder resulting in
variable
defects of mitochondrial oxidative respiration. Affected individuals present
in
infancy with hypertrophic cardiomyopathy and lactic acidosis. The severity is
variable, but can be fatal in the most severe cases. Additional clinical
symptoms
include oligohydramnios, hypotonia, psychomotor delay, spasticity, seizures,
dystonia, hypoglycemia, metabolic acidosis, high serum lactate and reduced
Complex
I & IV activity.
[0315] Loss of MT01 function can also result in encephalomyopathy, which
usually
manifests at 3 months of age. Symptoms include seizures, infantile spasms,
delayed
motor & cognitive development, axial hypotonia, chorio-athetoid movements, COX
negative muscle fibers, and Complex IV deficiency.
19. Combined Oxidative Phosphorylation Deficiency 16 (COXPD16)
[0316] Combined oxidative phosphorylation deficiency-16 (COXPD16) is caused
by homozygous mutations in the MRPL44 gene. MRPL44 encodes a structural
subunit of mitochondrial large (39S) ribosomal subunit and plays role in the
assembly
and stability of the 39S subunit. Age of onset is usually at 3 to 6 months.
Clinical
features include hypertrophic cardiomyopathy, steatosis, high levels of liver
transaminases, high serum lactate, reduced COX staining in muscle, and reduced
Complex I and IV activity.
[0317] Other mitochondrial ribosomal subunit disorders include disruptions in
MRPS16 and MRPS22, which encode components of the small ribosomal subunit.
Symptoms include early death and severe lactic acidosis. Alternatively,
disruptions in
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MRPL3, which encodes a component of the large ribosomal subunit, results in
cardiomyopathy and mental retardation.
20. Combined Oxidative Phosphorylation Deficiency 17 (COXPD17)
[0318] Combined oxidative phosphorylation deficiency-17 (COXPD17) is caused
by homozygous or compound heterozygous mutations in the ELAC2 gene, which
encodes a zinc phosphodiesterase protein with tRNA processing endonuclease
activity. The protein also interacts with PTCD1 and is ubiquitously expressed.
Combined oxidative phosphorylation deficiency-17 is an autosomal recessive
disorder
of mitochondrial dysfunction characterized by onset of severe hypertrophic
cardiomyopathy in the first year of life. Other features include hypotonia,
poor
growth, microcephaly, lactic acidosis, delayed psychomotor development,
impaired
central hearing, high alanine and glutamine levels, abnormal mitochondrial
cristae,
reduced Complex I and IV activity and failure to thrive. The disorder may be
fatal in
early childhood.
21. Combined Oxidative Phosphorylation Deficiency 5 (COXPD5)
[0319] Mutations in MRPS22 can result in combined oxidative phosphorylation
deficiency-5 (COXPD5). Patients show reduced activities of mitochondrial
respiratory chain complexes I, III, and IV, marked and generalized defect in
mitochondrial translation, microcephaly, dilated cardiomyopathy, dysmorphic
features, hypotonia, metabolic acidosis, transient seizures, poor growth, lack
of
development, and spastic tetraplegia.
[0320] Mutations in NDUFAll can result in mitochondrial complex I deficiency.
Symptoms include fatal infantile metabolic acidosis, encephalocardiomyopathy
with
brain atrophy, no motor development, and hypertrophic cardiomyopathy.
22. Combined Oxidative Phosphorylation Deficiency 9 (COXPD91
[0321] Combined oxidative phosphorylation deficiency-9 (COXPD9) is caused by
compound heterozygous mutations in the MRPL3 gene. Patients present with
failure
to thrive, poor feeding, hypertrophic cardiomyopathy, hepatomegaly,
psychomotor
retardation, mental retardation, increased plasma lactate and alanine,
abnormal liver
enzymes, and decrease in activity of mitochondrial respiratory complexes I,
III, IV,
and V, with a mild decrease in complex II.
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Camitine Disorders
[0322] Camitine (beta-hydroxy-gamma-trimethylaminobutyric acid) is an
essential
cofactor for transport of long chain fatty acids across mitochondrial
membranes,
permitting beta-oxidation. Camitine in body fluids is derived from the diet or
biosynthesis and is actively transported into muscle. Two biochemically and
clinically distinct disorders cause low concentrations of carnitine in
skeletal muscle.
Systemic carnitine deficiency shows low carnitine in the liver and/or plasma.
In
muscle carnitine deficiency, lipid storage myopathy occurs with low muscle
carnitine
but normal liver and serum carnitine.
[0323] The age of onset for carnitine deficiency, myopathic form occurs during
childhood ¨early adulthood. Symptoms include weakness, cardiomyopathy, and
congestive heart failure.
1. Camitine Acetyltransferase Deficiency
[0324] Camitine acetyltransferase (CRAT) deficiency is an autosomal recessive
disorder characterized by ataxia, oculomotor palsy, hypotonia, poor
respiration,
failure to thrive, and altered consciousness. CRAT functions in the
maintenance of
normal fatty acid metabolism by catalyzing the transfer of acyl groups from
acyl-CoA
thioester to carnitine. CRAT controls the ratio of acyl-CoA/CoA in
mitochondria,
peroxisomes, and endoplasmic reticulum. CRAT deficiency has been shown to be
associated with deletions of mitochondrial DNA, mainly the ND4-ND4L region, in
muscle. Other regions of the mitochondrial genome also showed deletions of
varying
size and extent, suggesting multiple deletions of the mitochondrial DNA.
2. Carnitine Palmitoyltransferase I Deficiency
[0325] Camitine palmitoyltransferase I (CPT I) deficiency is an autosomal
recessive
metabolic disorder that affects the mitochondrial oxidation of long-chain
fatty acids in
the liver and kidneys and is characterized by recurrent episodes of fasting-
induced
hypoketotic hypoglycemia and an elevated risk of liver failure. During
metabolic
crisis, blood tests reveal hypoglycemia, elevated levels of plasma camitine
and liver
transaminases, and mild hyperammonemia. Urine tests may show unusually low
levels of ketones, and medium-chain dicarboxylic aciduria. CPT I deficiency is
associated with mutations in the CPT1A gene, which encodes carnitine
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palmitoyltransferase IA. The camitine palmitoyltransferase enzyme system
comprising CPT I and CPT II, in combination with acyl-CoA synthetase and
camitine/acylcarnitine translocase, provides the mechanism by which long-chain
fatty
acids are transferred from the cytosol to the mitochondrial matrix. The CPT I
isozymes, CPT1A and CPT1B are located in the mitochondrial outer membrane,
whereas CPT II is located in the inner mitochondrial membrane.
3. Myopathic Camitine Deficiency
[0326] Myopathic camitine deficiency is a progressive autosomal recessive
disorder
characterized by lipid storage myopathy with low muscle camitine but normal
liver
and serum camitine. Clinical features include symmetric, proximal weakness in
the
face and tongue, cardiomyopathy, congestive heart failure, moderately elevated
serum
creatine kinase levels.
4. Primary Systemic Camitine Deficiency
[0327] Primary systemic camitine deficiency (CDSP) is an autosomal recessive
disorder of fatty acid oxidation caused by a homozygous or compound
heterozygous
mutation in the SLC22A5 gene. The SLC22A5 gene encodes solute carrier family
22
member 5 protein, which functions as a sodium-ion dependent, high affinity
camitine
transporter involved in the active cellular uptake of camitine. Mutations in
the
SLC22A5 gene result in a defective camitine transporter, which is expressed in
muscle, heart, kidney, and fibroblasts. This results in impaired fatty acid
oxidation in
skeletal and heart muscle. In addition, renal wasting of carnitine results in
low serum
levels and diminished hepatic uptake of camitine by passive diffusion, which
impairs
ketogenesis. If diagnosed early, all clinical manifestations of the disorder
can be
completely reversed by supplementation of camitine. However, if left
untreated,
patients will develop lethal heart failure.
5. Camitine Palmitoyltransferase II Deficiency
[0328] Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal
recessive disorder and is the most common inherited disorder of mitochondrial
long-
chain fatty acid oxidation and is associated with mutations in the CPT2 gene.
The
CPT2 gene encodes camitine palmitoyltransferase 2 an enzyme that is essential
for
fatty acid oxidation. Over 70 different mutations in the CPT2 gene have been
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identified. CPT2 mutations lead to a reduction in the activity of carnitine
palmitoyltransferase 2. There are three main types of CPT II deficiency: a
lethal
neonatal form, a severe infantile hepatocardiomuscular form, and a myopathic
form.
[0329] The lethal neonatal form becomes apparent soon after birth. Infants
with this
form of CPT II deficiency develop respiratory failure, seizures, liver
failure,
cardiomyopathy, and arrhythmia. Affected infants also exhibit hypoketotic
hypoglycemia and structurally abnormal brain and kidneys. Infants with the
lethal
neonatal form of CPT II deficiency typically survive for only a few days to a
few
months.
[0330] The severe infantile hepatocardiomuscular form of CPT II deficiency
affects
the liver, heart, and muscles. Signs and symptoms usually appear within the
first year
of life. This form involves recurring episodes of hypoketotic hypoglycemia,
seizures,
hepatomegaly, cardiomyopathy, and arrhythmia. Problems related to this form of
CPT II deficiency can be triggered by periods of fasting or by illnesses such
as viral
infections. Individuals with the severe infantile hepatocardiomuscular form of
CPT II
deficiency are at risk for liver failure, nervous system damage, coma, and
sudden
death.
[0331] The myopathic form is the least severe type of CPT II deficiency. This
form
is characterized by recurrent episodes of myalgia and rhabdomyolysis. The
destruction of muscle tissue results in myoglobinuria. Myoglobin can also
damage
the kidneys, in some cases leading to life-threatening kidney failure.
Episodes of
myalgia and rhabdomyolysis may be triggered by exercise, stress, exposure to
extreme temperatures, infections, or fasting. The first episode usually occurs
during
childhood or adolescence. Most people with the myopathic form of CPT II
deficiency
have no signs or symptoms of the disorder between episodes.
6. Carnitine-acylcarnitine Translocase Deficiency
[0332] Carnitine-acylcarnitine translocase deficiency (CACTD) is an autosomal
recessive metabolic disorder of long-chain fatty acid oxidation caused by a
homozygous or compound heterozygous mutation in the SLC25A20 gene. The
SLC25A20 gene encodes carnitine-acylcarnitine translocase (CACT), one of the
components of the carnitine cycle that mediates the transport of
acylcarnitines of
different length across the mitochondrial inner membrane from the cytosol to
the
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mitochondrial matrix for their oxidation by the mitochondrial fatty acid-
oxidation
pathway.
[0333] Individuals with CACTD exhibit hypoketotic hypoglycemia under fasting
conditions, hyperammonemia, elevated serum creatine kinase and transaminases,
dicarboxylic aciduria, very low free carnitine, and abnormal acylcarnitine
profile with
marked elevation of the long-chain acylcarnitines. Additional features include
neurologic abnormalities, cardiomyopathy and arrhythmias, skeletal muscle
damage,
and liver dysfunction. Most patients become symptomatic in the neonatal period
with
a rapidly progressive deterioration and a high mortality rate. However,
presentations
at a later age with a milder phenotype have been reported.
Cartilage-hair Hypoplasia
[0334] Cartilage-hair hypoplasia, a form of short-limbed dwarfism due to
skeletal
dysplasia, is caused by mutations in the RMRP gene. RMRP encodes an RNA with
endoribonuclease activity that cleaves mitochondrial RNA complementary to
light
chain of displacement loop. Clinical symptoms include short stature, joint
hyperextensibility, metaphyseal dysplasia, hypoplastic sparse hair, neuronal
dysplasia,
megacolon, malabsorption, increased risk of lymphoma & skin neoplasm,
susceptibility to chickenpox, lymphopenia, neutropenia, and hypoplastic
macrocytic
anemia.
Cerebrotendinous Xanthomatosis
[0335] Cerebrotendinous xanthomatosis (CTX), also known as Van Bogaer-
Scherer-Epstein disease, is an autosomal recessive lipid-storage disorder
caused by
the deficient activity of mitochondrial sterol 27-hydroxylase (CYP27A1). CTX
is
associated with mutations in the CYP27A1 gene, which encodes sterol 27-
hydroxylase. CTX is characterized by the formation of xanthomatous lesions in
many
tissues, particularly in the brain, eye lens, and tendons resulting in
progressive
neurologic dysfunction, premature atherosclerosis, and cataracts. Cholestanol,
the 5-
alpha-dihydro derivative of cholesterol, is enriched relative to cholesterol
in all
tissues. A diagnosis of CTX is typically made by demonstrating that
cholestanol is
present in abnormal amounts in the serum and tendon in suspected affected
individuals.
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Congenital Adrenal Hyperplasia
[0336] Congenital adrenal hyperplasia (CAH) comprises a group of monogenic
autosomal recessive disorders caused by an enzyme deficiency in steroid
biosynthesis.
All of the adrenal hyperplasia syndromes are examples of mixed hypo- and
hyperadrenocorticism. CAH is associated with 11-beta-hydroxylase deficiency
caused by a mutation in the CYP11B I gene. The CYP11B1 gene encodes 11-beta-
hydroxylase, which functions primarily in the mitochondria in the zona
fasciculata of
the adrenal cortex to convert 11-deoxycortisol to cortisol and 11-
deoxycorticosterone
to corticosterone. CAH due to 11-beta-hydroxylase deficiency results in
androgen
excess, virilization, and hypertension. The defect causes decreased cortisol
and
corticosterone synthesis in the zona fasciculata of the adrenal gland,
resulting in the
accumulation of 11-deoxycortisol and 11-deoxycorticosterone.
Congenital Muscular Dystrophy with Mitochondrial Structural Abnormalities
(Megaconial) (MDCMC)
[0337] Megaconial type congenital muscular dystrophy is caused by homozygous
or
compound heterozygous mutations in the choline kinase beta (CHKB) gene. This
form of autosomal recessive congenital muscular dystrophy is characterized by
early-
onset muscle wasting and mental retardation. Some patients develop fatal
cardiomyopathy. Muscle biopsy shows peculiar enlarged mitochondria that are
prevalent toward the periphery of the fibers but are sparse in the center.
Additional
clinical symptoms include hypotonia, progressive weakness, delayed walking,
small
head circumference, elevated creatine kinase, muscle necrosis, and increased
endomysial connective tissue.
Cerebral Creatine Deficiency Syndrome-3
[0338] Cerebral creatine deficiency syndromes (CCDS) comprise a group of
inborn
errors of creatine metabolism and include the X-linked creatine transporter
(SLC6A8)
deficiency (CCDS1) and the two autosomal recessive creatine biosynthesis
disorders,
guanidinoacetate methyltransferase (GAMT) deficiency (CCDS2) and L-
arginine:glycine amidinotransferase (AGAT or GATM) deficiency (CCDS3).
Cerebral creatine deficiency syndrome-3 (CCDS3) is associated with the
following
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AGAT mutations: Ala97ValfsX11; Trp149X; Arg169X; Tyr203Ser; and
Met371AsnfsX6. AGAT is localized to the mitochondrial intermembrane space.
[0339] These disorders are characterized by developmental delay/regression,
mental
retardation, severe depressive and cognitive speech disturbances, seizures,
and
depletion of creatine/phosphocreatine levels in the brain. Additional
manifestations
include muscular hypotonia and movement disorder (mainly extrapyramidal). The
characteristic biochemical hallmark of all CCDS is cerebral creatine
deficiency as
detected by proton magnetic resonance spectroscopy (H-MRS). Increased levels
of
guanidinoacetate in body fluids are indicative of GAMT deficiency, whereas
reduced
guanidinoacetate levels are indicative of AGAT deficiency. An elevated urinary
creatine/creatinine ratio is associated with SLC6A8 deficiency.
Deafness
1. Maternal Nonsyndromic Deafness
[0340] Mutations in mitochondrial DNA (mtDNA) have been found to be associated
with nonsyndromic sensorineural hearing loss. Mitochondrially inherited
nonsyndromic sensorineural deafness can be caused by mutations in any 1 of
several
mitochondrial genes, including MTRNR1, MTTS1, MTC01, MTTH, MTND1, and
MTTI. Matrilineal relatives within and among families carrying certain
pathogenic
mitochondrial mutations exhibit a wide range of penetrance, severity, and age
of onset
of hearing loss, indicating that the mitochondrial mutations by themselves are
not
sufficient to produce a deafness phenotype. Modifier factors, such as nuclear
and
mitochondrial genes, or environmental factors, such as exposure to
aminoglycosides,
appear to modulate the phenotypic manifestations.
2. Maternal Syndromic Deafness
[0341] Mitochondrially inherited syndromic sensorineural deafness can be
caused
by mutations in any 1 of several mitochondrial genes (including MTTL1, MTTS1,
MTTS2, MTTL, MTTK, MTTQ), large (> 1 kb) heteroplasmic deletions, or large (>
1
kb) heteroplasmic partial duplications.
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3. Sporadic Syndromic Deafness
[0342] Sporadic syndromic deafness can be caused by single large mtDNA
deletion
or mutations in MTC01. Clinical symptoms associated with MTC01-induced
syndromic deafness include cataracts, progressive sensorineural deafness,
myopathy,
ataxia, myoclonic epilepsy, visual loss, optic atrophy, reduced COX activity,
cerebellar atrophy, and bilateral small symmetrical nodular hyperintensities.
Mutations in MTC01 can result in sideroblastic anemia, exercise intolerance
and
LHON.
4. Autosomal Dominant Deafness-64 (DFNA64)
[0343] Autosomal dominant deafness-64 (DFNA64) is caused by heterozygous
mutations in the DIABLO gene. The age at onset ranges between 12 and 30 years
(average age of 22). The severity of hearing impairment ranges from severe to
moderate to mild and correlates with age. High frequency tinnitus was reported
in
73% of affected individuals at the onset of hearing loss.
5. Deafness-Dystonia-Dementia Syndromes
[0344] Mohr-Tranebjaerg Syndrome and Jensen Syndrome have been found to be
caused by mutations in the TIMM8A (DDP) gene, which aid in the importation of
metabolite transporters from cytoplasm to mitochondrial inner membrane.
Clinical
symptoms of Mohr-Tranebjaerg Syndrome (Deafness-dystonia Syndrome) include
progressive sensory-neural hearing loss, myopia, reduced visual acuity,
constricted
visual fields, retinal change, dystonia, mental deficiency, and cortical
blindness.
Clinical symptoms of Jensen Syndrome include blindness, optic atrophy,
sensorineural hearing loss, dementia, CNS calcifications, and muscle wasting.
[0345] Mutations in the chaperonin HSP60 also impact mitochondrial protein
importation and may lead to hereditary spastic paraplegia.
6. Dystonia, Deafness with Leigh-like Syndrome (MEGDEL)
[0346] 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-
like
Syndrome (MEGDEL) is an autosomal recessive disorder characterized by
childhood
onset of delayed psychomotor development or psychomotor regression,
sensorineural
deafness, spasticity or dystonia, and increased excretion of 3-
methylglutaconic acid.
MEGDEL is caused by homozygous or compound heterozygous mutations in the
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SERAC1 gene, which plays a role in phospholipid exchange and intracellular
cholesterol trafficking. Brain imaging of affected subjects shows cerebral and
cerebellar atrophy as well as lesions in the basal ganglia reminiscent of
Leigh
Syndrome. Clinical symptoms include hypotonia, encephalopathy (Leigh-like
Syndrome), mental retardation, sensorineural deafness, spasticity, dystonia,
hepatopathy, increased serum lactate and alanine, hyperammonemia, 3-
Methylglutaconic aciduria, high transaminases, coagulopathy, high serum a-
fetoprotein, mitochondrial oxidative phosphorylation defects, abnormal
mitochondria,
abnormal phosphatidylglycerol and cardiolipin profiles in fibroblasts, and
abnormal
accumulation of unesterified cholesterol within cells.
7. Reticular Dysgenesis
[0347] Reticular dysgenesis is one of the rarest and most severe forms of
combined
immunodeficiency and is caused by a homozygous or compound heterozygous
mutation in the mitochondrial adenylate kinase-2 gene (AK2). Reticular
dysgenesis is
characterized by bilateral sensorineural deafness, congenital agranulocytosis,
lymphopenia, and lymphoid and thymic hypoplasia with absent cellular and
humoral
immunity functions.
8. Steroid-resistant Nephrotic Syndrome & Sensorineural Hearing Loss
(C0Q10D6)
[0348] Primary coenzyme Q10 deficiency-6 (C0Q10D6) is an autosomal recessive
disorder characterized by onset in infancy of severe progressive nephrotic
syndrome
resulting in end-stage renal failure and sensorineural deafness. COQ10D6 is
caused
by homozygous or compound heterozygous mutations in the COQ6 gene. Renal
biopsy usually shows focal segmental glomerulosclerosis (FSGS). Clinical
features
include bilateral sensorineural deafness and steroid-resistant nephrotic
syndrome.
9. Cataracts, Growth hormone Deficiency, Sensory Neuropathy, Sensorineural
Hearing Loss, Skeletal Dysplasia (CAGSSS)
[0349] Mutations in isoleucyl-tRNA synthetase 2 (IARS2), an aminoacyl-tRNA
synthetase, results in CAGSSS. Clinical symptoms include sensorineural
deafness,
cataracts, skeletal dysplasia, facial dysmorphism, short stature, hip
disorders,
scoliosis, cervical stenosis, C2-odontoid hypoplasia, spondylo-epiphyseal
dysplasia,
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sensory loss polyneuropathy, growth hormone deficiency, and pituitary
adenohypophysis atrophy. Alternate IARS2 syndromes include Leigh Syndrome.
Diabetes
103501 Diabetes may arise as a result of mutations in MTTL, MTTK, MTTE,
MTTS2, mitochondrial elongation factor G2 (GFM2), single large mtDNA
deletions,
and large scale mtDNA tandem duplications. Diabetes is usually observed in
patients
affected with Kearns-Sayre Syndrome, Wolfram Syndrome, Friedreich's ataxia and
Metabolic Syndrome in obesity.
Dimethylglycine Dehydrogenase Deficiency
[0351] Dimethylglycine dehydrogenase deficiency (DMGDHD) is an autosomal
recessive glycine metabolism disorder characterized by chronic muscle fatigue,
elevated serum levels of creatine kinase, and a fishlike body odor. DMGDHD is
also
characterized by an increase of N,N-dimethylglycine (DMG) in serum and urine.
DMGDHD is associated with mutations in the DMGDH gene, which encodes
dimethylglycine dehydrogenase (DMGDH), a mitochondrial matrix flavoprotein
that
catalyzes the oxidative demethylation of dimethylglycine to form sarcosine.
DMGDH has been identified as a monomer in the mitochondrial matrix where it
uses
flavin adenine dinucleotide and folate as cofactors.
Encephalopathies
1. Multiple Mitochondrial Encephalopathy
103521 Multiple mitochondrial encephalopathies can result from Multiple
Mitochondrial Dysfunctions Syndrome-1 (MMDS1), Multiple Mitochondrial
Dysfunctions Syndrome-2 (MMDS2), and Multiple Mitochondrial Dysfunctions
Syndrome-3 (MMDS3). Multiple mitochondrial dysfunctions syndrome is a severe
autosomal recessive disorder of systemic energy metabolism, resulting in
weakness,
respiratory failure, lack of neurologic development, lactic acidosis, and
early death.
MMDS1 be caused by a homozygous or compound heterozygous mutation in the
NFUl gene. MMDS2 can be caused by homozygous mutation in the BOLA3 gene.
MMDS3 can be caused by homozygous mutation in the IBA57 gene.
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2. Encephalopathies Associated with Mitochondrial Complex I Deficiency
[0353] Encephalopathy can arise as a result of mitochondrial Complex I
deficiencies. Complex I deficiencies leading to encephalopathy are associated
with
mutations in the following genes: NDUFA1, NDUFAll, C60RF66, VARS2,
NDUFA12L, NDUFS1, NDUFV1, NUBPL, and NDUFV2.
3. Childhood Leukoencephalopathy and Complex II Deficiency
[0354] Childhood leukoencephalopathy associated with mitochondrial Complex II
deficiency can be caused by mutations in the SDHAF1 gene, which encodes
succinate
dehydrogenase complex assembly factor 1.
4. Encephalopathies Associated with Mitochondrial Complex III Deficiency
[0355] Encephalopathy can arise as a result of mitochondrial Complex III
deficiencies. Complex III deficiencies leading to encephalopathy are
associated with
mutations in the following genes: UQCRQ, UQCC2, LYRM7, and UQCRC2.
5. Encephalopathies Associated with Mitochondrial Complex IV Deficiency
[0356] Encephalopathies associated with mitochondrial Complex IV deficiency
include encephalocardiomyopathies due to mutations in the MT01 gene and/or
C120RF62 genes, encephalomyopathies due to mutations in the FASTI(D2 and/or
AIFM1 genes, and neonatal hepatoencephalopathy due to mutations in the SCO1
gene.
6. Encephalopathies Associated with Mitochondrial Complex V Deficiency
[0357] Encephalopathies associated with mitochondrial Complex V deficiency
include neonatal encephalopathy, which is caused by mutation in the ATP5A1
gene,
and neonatal encephalocardiomyopathy, which is caused by mutation in the
TMEM70
gene.
7. Hyperammonemia due to Carbonic Anhydrase VA Deficiency
[0358] Hyperammonemia due to carbonic anhydrase VA deficiency (CA5AD) is
caused by homozygous mutation in the CASA gene. The disorder is characterized
clinically by acute onset of encephalopathy in infancy or early childhood.
Biochemical evaluation shows multiple metabolic abnormalities, including
metabolic
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acidosis and respiratory alkalosis. Other abnormalities include hypoglycemia,
increased serum lactate and alanine, and evidence of impaired provision of
bicarbonate to essential mitochondrial enzymes. Apart from episodic acute
events in
early childhood, the disorder showed a relatively benign course.
8. Early Infantile Epileptic Encephalopathy-3
[0359] Early infantile epileptic encephalopathy-3 (EIEE3) is caused by
homozygous
mutation in the SLC25A22 gene. EIEE3 is characterized by onset during the
first
months of life of erratic refractory seizures, usually myoclonic. The
prognosis is
poor, and most children with the condition either die within 1 to 2 years
after birth or
survive in a persistent vegetative state. The EEG pattern often shows a
suppression-
burst pattern with high-voltage bursts of slow waves mixed with multifocal
spikes
alternating with isoelectric suppression phases.
9. 2,4-Dienoyl-CoA Reductase Deficiency
[0360] 2,4-Dienoyl-CoA reductase deficiency (DECRD) is caused by a
homozygous mutation in the NADK2 gene. DECR deficiency is a rare autosomal
recessive inborn error of metabolism resulting in mitochondrial dysfunction.
Affected
individuals have a severe encephalopathy with neurologic and metabolic
dysfunction
beginning in early infancy. Laboratory studies show decreased activity of the
mitochondrial NADP(H)-dependent enzymes DECR1 and AASS, resulting in
increased C10:2-carnitine levels and hyperlysinemia.
10. Infection-induced Acute Encephalopathy-3
[0361] Infection-induced acute encephalopathy-3 (IIAE3), also known as acute
necrotizing encephalopathy, is caused by heterozygous mutation in the RANBP2
gene. Affected individuals typically present with IIAE3 following febrile
illness.
11. Ethylmalonic Encephalopathy
[0362] Ethylmalonic encephalopathy (EE) is caused by a homozygous or compound
heterozygous mutation in the ETHE1 gene, which encodes a mitochondrial matrix
protein. Ethylmalonic encephalopathy is an autosomal recessive severe
metabolic
disorder of infancy affecting the brain, gastrointestinal tract, and
peripheral vessels.
The disorder is characterized by neurodevelopmental delay and regression,
prominent
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pyramidal and extrapyramidal signs, recurrent petechiae, orthostatic
acrocyanosis, and
chronic diarrhea. Brain MRI shows necrotic lesions in deep gray matter
structures.
Death usually occurs in the first decade of life.
12. Hypomyelinating Leuko dystrophy
[0363] Hypomyelinating leukodystrophy (HLD4), also known as mitochondrial
Hsp60 chaperonopathy, is caused by mutation in the HSPD I gene. Affected
individuals experience a form of severe hypomyelinating leukoencephalopathy.
Age
of onset typically occurs between birth and three month. The disorder is
characterized
by hypotonia, nystagmus, and psychomotor developmental delay, followed by
appearance of prominent spasticity, developmental arrest, and regression.
Exocrine Pancreatic Insufficiency, Dyserythropoietic Anemia and Calvarial
Hyperostosis
[0364] Exocrine pancreatic insufficiency, dyserythropoietic anemia and
calvarial
hyperostosis is caused by mutations in cytochrome c oxidase, Subunit IV,
Isoform 2
(C0X4I2). Clinical features include exocrine pancreatic insufficiency,
steatorrhea,
malabsorption of lipid-soluble vitamins, calvarial hyperostosis, delayed bone
age,
osteopenia and dyserythropoietic, megaloblastic anemia.
Glutaric Aciduria Type 1
[0365] Glutaric aciduria type I (GA-1), also known as glutaric acidemia, is an
autosomal recessive disorder characterized by episodes of severe brain
dysfunction,
spasticity, hypotonia, dystonia, seizures, and developmental delays. GA-1 is
associated with mutations in the GCDH gene causing a deficiency of glutaryl-
CoA
dehydrogenase (GCDH) and leading to an accumulation of glutaric and 3-
hydroxyglutaric acids and secondary carnitine deficiency. Elevated urine C5DC
serves as a marker for the detection of GA-1.
[0366] GCDH is an acyl dehydrogenase that catalyzes the oxidative
decarboxylation
of glutaryl-CoA to crotonyl-CoA and CO2 in the degradative pathway of L-
lysine, L-
hydroxylysine, and L-tryptophan metabolism. The enzyme exists as a
homotetramer
of 45-kD subunits in the mitochondrial matrix. Deficiencies in GCDH lead to an
accumulation of L-lysine, L-hydroxylysine, L-tryptophan, and their
metabolites.
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Glycine Encephalopathy
[0367] Glycine encephalopathy (GCE), also known as nonketotic hyperglycinemia
(NKH), is an inborn error of glycine metabolism caused by a deficiency of the
glycine
cleavage system. GCE is characterized by abnormally high levels of glycine
leading
to a progressive lethargy, feeding difficulties, hypotonia, dystonia, and
respiratory
distress. The enzyme system for cleavage of glycine, which is confined to the
mitochondria, is composed of four protein components: P protein (a pyridoxal
phosphate-dependent glycine decarboxylase), H protein (a lipoic acid-
containing
protein), T protein (a tetrahydrofolate-requiring enzyme), and L protein (a
lipoamide
dehydrogenase). GCE may be caused by a defect in the H, P, or T proteins.
Hepatic Failure
[0368] Acute infantile liver failure is caused by mutations in tRNA 5-
methylaminomethy1-2-thiouridylate methyltransferase (TRMU), which encodes a
mitochondria-specific tRNA-modifying enzyme. Age of onset for this disorder is
usually between 1 to 4 months and is characterized by hepatic failure,
irritability, poor
feeding, and vomiting. Clinical features include jaundiced sclerae, distended
abdomen, hepatomegaly, lethargy, coagulopathy, low albumin, direct
hyperbilirubinemia, metabolic acidosis, hyperlactatemia, high a-fetoprotein,
high
phenylalanine, tyrosine, methionine, glutamine and alanine in plasma, high
lactate,
phenylalanine and tyrosine metabolites, ketotic dicarboxylic and 3-
hydroxydicarboxylic aciduria, and reduced Complex I, III and IV activity.
[0369] Hepatic failure with hyperlactatemia is caused by mutations in DGUOK,
POLG, and MPV17.
2-Hydroxyglutaric Aciduria
[0370] 2-Hydroxyglutaric aciduria is an autosomal recessive neurometabolic
disorder characterized by developmental delay, epilepsy, hypotonia, and
dysmorphic
features. Mutations in the D2HGDH gene, encoding D-2-hydroxyglutarate
dehydrogenase (D2HGDH) are associated with D-2-hydroxyglutaric aciduria (D-2-
HGA) type I. D2HGDH is a mitochondrial enzyme belonging to the FAD-binding
oxidoreductase/transferase type 4 family that is active in liver, kidney,
heart, and
brain where it converts D-2-hydroxyglutarate (D-2-HG) to 2-ketoglutarate.
Mutations
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in the IDH2 gene, encoding isocitrate dehydrogenase 2 (IDH2) are associated
with D-
2-HGA type II. IDH2 is a mitochondrial NADP-dependent isocitrate dehydrogenase
that catalyzes oxidative decarboxylation of isocitrate to alpha-ketoglutarate,
producing NADPH.
[0371] Another form of 2-hydroxyglutaric aciduria, L-2-hydroxyglutaric
aciduria
(L-2-HGA) is associated with mutations in the L2HGDH gene, encoding L-2-
hydroxyglutarate dehydrogenase, an FAD-dependent mitochondrial enzyme that
oxidizes L-2-hydroxyglutarate to alpha-ketoglutarate. L-2-HGA particularly
affects
the cerebellum, resulting in balance and muscle coordination abnormalities.
Clinical
manifestations of infantile onset L-2-HGA include ataxia, mental retardation,
macrocephaly, a potential increased risk of brain neoplasm, leukodystrophy,
and the
presence of L-2-hydroxyglutaric acid in the urine and cerebrospinal fluid.
Adult-
onset L-2-HGA is associated with a c.959delA mutation and causes movement
disorder, tremor, and saccades.
[0372] Combined D,L-2-hydroxyglutaric aciduria (D,L-2HGA) is characterized by
neonatal-onset encephalopathy with severe muscular weakness, intractable
seizures,
respiratory distress, and lack of psychomotor development leading to early
death.
3-Hydroxyacyl-CoA Dehydrogenase Deficiency
[0373] 3-Hydroxyacyl-CoA dehydrogenase deficiency, also known as HADH
deficiency, is an autosomal recessive metabolic disorder, resulting from
mutations in
the HADH gene. The 3-Hydroxyacyl-CoA dehydrogenase protein functions in the
mitochondria' matrix to catalyze the oxidation of straight-chain 3-hydroxyacyl-
CoAs
as part of the beta-oxidation pathway. Human HADH encodes a deduced 314-amino
acid protein comprising a 12-residue mitochondrial import signal peptide and a
302-
residue HADH protein with a calculated molecular mass of 34.3 kD. 3-
Hydroxyacyl-
CoA dehydrogenase has a preference for medium chain substrates, whereas short
chain 3-hydroxyacyl-CoA dehydrogenase (SCADH) acts on a variety of substrates,
including steroids, cholic acids, and fatty acids with a preference for short
chain
methyl-branched acyl-CoAs. Mutations in HADH cause one form of familial
hyperinsulinemic hypoglycemia (FHH). FHH is the most common cause of
persistent
hypoglycemia in infancy.
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Hypercalcemia Infantile
[0374] Hypercalcemia infantile is an autosomal recessive disorder
characterized by
severe hypercalcemia, failure to thrive, vomiting, dehydration, and
nephrocalcinosis.
Hypercalcemia infantile is associated with homozygous or compound heterozygous
mutations in the CYP24A1 gene. 24-Hydroxylase (CYP24A1) is a mitochondrial
enzyme found mainly in the kidney, bone and intestine, and is likely present
in all
cells that express the vitamin D receptor. CYP24A1 is a 514-amino acid protein
with
a complex structure of a helices and i3 strands. It interacts with the
mitochondrial
membrane, adrenodoxin, heme, and vitamin D molecules. Disruption of this
structure
impairs the function of the enzyme. Tight control of the vitamin D system
requires
inactivation of its active compound 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)
through 24-hydroxylation by means of the CYP24A1 enzyme and degradation to
calcitroic acid.
Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) Syndrome
[0375] HHH Syndrome is an autosomal recessive early onset (infancy to 18
years)
disorder caused by mutations in the SLC25A15 gene, which encodes the
mitochondrial ornithine transporter. Patients with HHH exhibit partial
impairment of
uptake of ornithine by mitochondria. Symptoms include mental retardation and
myoclonic seizures associated with hyperornithinemia, hyperammonemia, and
homocitrullinemia, progressive spastic paraparesis, protein intolerance,
stuporous
episodes, cerebellar ataxia, muscular weakness in both legs, myoclonus,
lethargy,
dysmetria, dysdiadochokinesis, scanning speech, learning difficulties,
buccofaciolingual dyspraxia, episodic vomiting, retinal depigmentation, and
chorioretinal thinning.
Immunodeficiency with Hyper-IgM Type 5
[0376] Immunodeficiency with hyper-IgM type 5 (HIGM5) is an autosomal
recessive disorder caused by homozygous or compound heterozygous mutations in
the
gene encoding uracil-DNA glycosylase (UNG). HIGM5 is characterized by
defective
normal or elevated serum IgM concentrations in the presence of diminished or
absent
IgG, IgA, and IgE concentrations, indicating a defect in the class-switch
recombination (CSR) process. UNG removes uracil in DNA resulting from
deamination of cytosine or replicative incorporation of dUMP instead of dTMP,
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thereby suppressing GC-to-AT transition mutations. The UNG gene encodes two
isoforms that are individually targeted to the mitochondria and nucleus. The
mitochondrial isoform is referred to as UNG1, UDG1, or UDG1M, and the nuclear
isoform is referred to as UNG2, UDG1A, or UDG1N. HIGM5 is associated with
mutations in the UNG gene. Patients with HIGM5 typically experience recurrent
bacterial infections and often exhibit lymphoid hyperplasia.
Inflammatory Myopathies
1. Inclusion Body Myositis (IBM)
[0377] IBM or Inflammatory Myopathy with Vacuoles, Aggregates and
Mitochondrial Pathology (IM-VAMP) is a sporadic progressive condition that
typically manifests in 9 out of 106 individuals at > 50 years of age. Clinical
features
include proximal and distal weakness, dysphagia, Inflammatory myopathy with
Mitochondrial pathology (PM-Mito), respiratory failure, aspiration, cachexia,
muscle
atrophy, diminished tendon reflexes, polyneuropathy, inflammation, muscle
fiber
hypertrophy, rimmed vacuoles with granular material & filaments ((3-Amyloid,
Desmin; Ubiquitin; Transglutaminases 1 & 2), aggregates (stain for SMI-31
antibody,
LC-3,13-amyloid, VCP, ubiquitin, aB-crystallin), COX deficient and SDH +
muscle
fibers, multiple mtDNA deletions, cricopharyngeus dysfunction, fatty
infiltration,
elevated transglutaminase activity, MHC I upregulation in muscle fibers, and
increased frequency of non-organ specific autoantibodies.
[0378] Variant syndromes include autosomal dominant IBM and polymyositis with
mitochondria' pathology.
2. Inflammatory Myo_pathy + Mitochondrial Pathology in Muscle (IM-Mito)
[0379] The age of onset for IM-Mito ranges from 43 to 71 years. Disease
progression is slower than IBM. Symptoms include proximal and distal weakness,
elevated serum creatine kinase, COX-negative and SDH-positive muscle fibers,
endomysial inflammation, focal invasion of muscle fibers by inflammatory
cells,
multiple mtDNA deletions, and LC-3 and/or aB-crystallin aggregates in muscle
fibers.
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3. Granulomatous Myopathies with Anti-mitochondrial Antibodies
[0380] Granulomatous myopathies with anti-mitochondrial antibodies account for
11% of inflammatory myopathies in Tokyo and typically manifests between 33 to
72
years of age. Clinical features include primary biliary cirrhosis, cardiac
arrhythmias,
muscle weakness, atrophy, respiratory defects, skin rash, elevated anti-
mitochondrial
autoantibodies, high serum creatine kinase, elevated alkaline phosphatase,
endomysial
fibrosis, necrosis and regeneration, inflammation, granulomas and MHC I
upregulation in muscle fibers.
[0381] Other inflammatory myopathies include, but are not limited to,
necrotizing
myopathy with pipestem capillaries, myopathy with deficient chondroitin
sulfate C in
skeletal muscle connective tissue, benign acute childhood myositis, idiopathic
orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated myositis, Facioscapulohumeral dystrophy (FSH), Limb-Girdle
dystrophy,
familial idiopathic inflammatory myopathy, Schmidt Syndrome (Diabetes
mellitus,
Addison disease, Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS),
focal myositis, autoimmune fasciitis, Spanish toxic oil-associated fasciitis,
Eosinophilic fasciitis, Macrophagic myofasciitis, Graft-vs-host disease
fasciitis,
Eosinophilia-myalgia Syndrome, and perimyositis.
Isovaleric Acidemia
[0382] Isovaleric acidemia (IVA), also known as isovaleric aciduria, is an
autosomal recessive inborn error of leucine metabolism caused by a deficiency
of the
mitochondrial enzyme isovaleryl-CoA dehydrogenase (IVD) resulting in the
accumulation of derivatives of isovaleryl-CoA such as isovaleric acid, which
is toxic
to the central nervous system. There are two forms of IVA. The acute neonatal
form
leads to pernicious vomiting, massive metabolic acidosis, and rapid death. The
chronic form results in periodic attacks of severe ketoacidosis with
asymptomatic
intervening periods. Symptoms of IVA include convulsions, lethargy,
dehydration,
moderate hepatomegaly, depressed platelets and leukocytes, and a distinctive
odor
resembling that of sweaty feet.
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Kearns-Sayre Syndrome
[0383] Kearnes-Sayre Syndrome (KSS), also known as oculocranisomatic disorder
or oculocraniosomatic neuromuscular disorder with ragged red fibers, is a
mitochondrial myopathy that is caused by various mitochondrial deletions.
Single
large mtDNA deletions (2 to 8 kb) account for 80% of KSS mutations. The mtDNA
deletions that cause KSS result in the impairment of oxidative phosphorylation
and a
decrease in cellular energy production. In most instances, KSS arises from
sporadic
somatic mutations occurring after conception. Rarely, the mutation is
transmitted
through maternal inheritance.
[0384] Clinical features include progressive external ophthalmoplegia,
pigmentary
degeneration of retina (retinitis pigmentosa), heart block, mitochondrial
myopathy,
limitation or absence of movement in all fields of gaze, ptosis, dysphagia,
weight loss,
weakness, occasional fatigue or pain on exertion, sensory-motor
polyneuropathy,
stroke, reduced respiratory drive, hearing loss, ataxia, dementia, or impaired
intellect,
spasticity, growth hormone deficiency, increased tendon reflexes,
endocrinopathies,
glucose intolerance, hypothyroidism, hypoparathyroidism, short stature, ragged
red
fibers, variation in muscle fiber size, lactic acidosis, high CSF protein, low
5-
methyltetrahydrofolate (5-MTHF) in CSF, high homovanillic acid (HVA) in CSF,
abnormal choroid plexus function, basal ganglia calcifications, cerebral and
cerebellar
atrophy, and status spongiosis in gray and white matter.
[0385] Another variant syndrome related to KSS, or other disorders having a
single
large mtDNA deletion include 2-oxoadipic aciduria and 2-aminoadipic aciduria.
Affected patients exhibit episodes of ketosis and acidosis, and may experience
coma.
Limb-girdle Muscular Dystrophy (LGMD) Syndromes
[0386] LGMD 1 is an autosomal dominant disorder characterized by adult onset
of
proximal muscle weakness, beginning in the hip girdle region and later
progressing to
the shoulder girdle region. Distal muscle weakness may occur later. Autosomal
dominant limb-girdle muscular dystrophy (LGMD) type lA is caused by a
heterozygous mutation in the gene encoding myotilin (TTID). Other forms of
autosomal dominant LGMD include LGMD1B, caused by mutations in the LMNA
gene; LGMD1C, caused by mutations in the CAV3 gene; LGMD1E, caused by
mutations in the DNAJB6 gene; LGMD1F, caused by mutations in the TNP03 gene;
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LGMD1G, which maps to chromosome 4q21; and LGMD1H, which maps to
chromosome 3p25-p23. The symbol LGMD1D was formerly used for a disorder later
found to be the same as desmin-related myopathy.
[0387] Autosomal recessive forms of LGMD include LGMD2A, caused by
mutations in Calpain-3; LGMD2B, caused by mutations in Dysferlin; LGMD2C,
caused by mutations in 7-Sarcoglycan; LGMD2D, caused by mutations in a-
Sarcoglycan; LGMD2E, caused by mutations ini3-Sarcoglycan; LGMD2F, caused by
mutations in S-Sarcoglycan; LGMD2G, caused by mutations in Telethonin;
LGMD2H, caused by mutations in TRIM32; LGMD2I (MDDGC5), caused by
mutations in FKRP; LGMD2J, caused by mutations in Titin; LGMD2K (MDDGC1),
caused by mutations in POMT1; LGMD2L, caused by mutations in AN05;
LGMD2M (MDDGC4), caused by mutations in Fukutin; LGMD2N (MDDGC2),
caused by mutations in POMT2; LGMD20 (MDDGC3), caused by mutations in
POMGnTl; LGMD2P (MDDGC9), caused by mutations in DAG1; LGMD2Q,
caused by mutations in Plectin lf; LGMD2R, caused by mutations in Desmin; and
LGMD2S, caused by mutations in TRAPPC11.
Leukodystrophy
[0388] Mutations in COX6B1, which encodes a Complex IV structural subunit, can
result in mitochondrial complex IV deficiency. Symptoms include muscle
weakness,
pain, unsteady gait, visual loss, progressive neurological deterioration,
cognitive
decline, leukodystrophic brain changes, seizures, ataxia, increased serum and
CSF
lactate and decreased COX activity in muscle.
[0389] Mutations in Apoptogenic protein 1 (APOPT1), which mediates
mitochondria-induced cell death in vascular smooth muscle cells, can result in
cavitating leukodystrophy. This disorder typically manifests between the ages
of 2 to
years. Additional clinical features include spastic tetraparesis, ataxia,
sensory-
motor polyneuropathy, reduced cognition, reduced COX staining, large
mitochondria
with osmophilic inclusions, and reduced Complex IV activity.
[0390] Mutations in SDHB can result in leukodystrophy, which usually presents
at 1
year of age. Clinical features include loss of motor skills, leukodystrophy in
deep
white matter and corpus callosum, and reduced Complex II activity.
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[0391] Leukodystrophy may arise as a result of large mtDNA deletions. Clinical
features include progressive ataxia, bulbar palsy, white-matter lesions in
occipital to
parietal lobes, and high CSF lactate.
Maple Syrup Urine Disease
[0392] Maple syrup urine disease (MSUD) can be caused by homozygous or
compound heterozygous mutations in at least 3 genes: BCKDHA, BCKDHB, and
DBT. These genes encode 2 of the catalytic components of the branched-chain
alpha-
keto acid dehydrogenase complex (BCKDC), which catalyzes the catabolism of the
branched-chain amino acids, leucine, isoleucine, and valine. Maple syrup urine
disease caused by a mutation in the El-alpha subunit gene is referred to as
MSUD
type IA; that caused by a mutation in the El-beta subunit gene as type TB; and
that
caused by defect in the E2 subunit gene as type II. Mutations in the third
component,
E3 (DLD), on chromosome 7q31, cause an overlapping but more severe phenotype
known as dihydrolipoamide dehydrogenase deficiency (DLDD). DLD deficiency is
sometimes referred to as MSUD3.
[0393] Clinical features of maple syrup urine disease include mental and
physical
retardation, neuropathy, ataxia, dystonia, athetosis, dysarthria, weakness,
ophthalmoplegia, hearing loss, drowsiness, seizures, feeding problems, reduced
tendon reflexes, sensory loss/pain, endoneurial edema, high lactic acid, and a
maple
syrup odor to the urine. The keto acids of the branched-chain amino acids are
present
in the urine, resulting from a block in oxidative decarboxylation. There are 5
clinical
subtypes of MSUD: the 'classic' neonatal severe form, an 'intermediate' form,
an
'intermittent' form, a 'thiamine-responsive' form, and an 'E3-deficient with
lactic
acidosis' form. All of these subtypes can be caused by mutations in any of the
4 genes
mentioned above, except for the E3-deficient form, which is caused only by a
mutation in the E3 gene.
3-Methylcrotonyl-CoA Carboxylase Deficiency
[0394] 3-Methylcrotonyl-CoA carboxylase (MCC), deficiency also known as 3-
methylcrotonylglycinuria, is an autosomal recessive disorder of leucine
catabolism
with a variable phenotype, ranging from neonatal onset with severe
neurological
involvement to asymptomatic adults. Common symptoms include feeding
difficulties, recurrent episodes of vomiting and diarrhea, lethargy, and
hypotonia.
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MCC is a heteromeric biotin-dependent mitochondrial enzyme composed of alpha
subunits and smaller beta subunits, encoded by MCC1 and MCC2, respectively.
MCC is essential for the catabolism of leucine.
Methylmalonic Aciduria
[0395] Methylmalonic aciduria (MMA), also known as methylmalonyl-CoA
epimerase deficiency, is an autosomal recessive disorder characterized by
progressive
encephalopathy, dehydration, developmental delays, failure to thrive,
lethargy,
seizures, and vomiting. MMA is caused by mutations in the MUT, MMAA, MMAB,
MMADHC, and MCEE genes. The long-term effects of MMA depend on which gene
is mutated and the severity of the mutation.
[0396] Mutations in the MUT gene cause a deficiency of methylmalonyl-CoA
mutase (MUT), which is a vitamin B12-dependent mitochondrial enzyme that
catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA. Mutations in
the
MUT gene lead to a toxic accumulation of methylmalonic acid in the blood. The
proteins encoded by the MMAA, MMAB, and MMADHC genes are required for the
proper function of MUT. Mutations affecting these genes can impair the
activity of
MUT, leading to methylmalonic aciduria. Mutations in the MCEE gene, which
encodes methylmalonyl CoA epimerase, lead to a mild form of methylmalonic
aciduria.
Miller Syndrome
[0397] Miller Syndrome, also known as postaxial acrofacial dystosis, is an
autosomal recessive disorder characterized by severe micrognathia, cleft lip
and/or
palate, hypoplasia or aplasia of the postaxial elements of the limbs, coloboma
of the
eyelids, and supernumerary nipples. Miller Syndrome is associated with
mutations in
the DHODH gene encoding dihydroorotate (DHO) dehydrogenase. Dihydroorotate
dehydrogenase catalyzes the fourth enzymatic step in de novo pyrimidine
biosynthesis. DHO dehydrogenase is a monofunctional protein located on the
outer
surface of the inner mitochondrial membrane.
mtDNA Depletion Syndrome-2 (MTDPS2)
[0398] Mitochondrial DNA Depletion Syndrome-2 (MTDPS2) is an autosomal
recessive disorder characterized primarily by childhood onset of muscle
weakness
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associated with depletion of mtDNA in skeletal muscle. MTDPS2 is caused by
homozygous or compound heterozygous mutations in the nuclear-encoded
mitochondrial thymidine kinase gene (TK2). There is wide clinical variability;
some
patients have onset in infancy and show a rapidly progressive course with
early death
due to respiratory failure, whereas others have later onset of a slowly
progressive
myopathy.
[0399] Clinical features include gait impairment, hypotonia, weakness,
respiratory
failure, paralysis, gynecomastia, myopathy, chronic partial denervation, mtDNA
depletion, reduced Complex I, III, IV and V activity, and elevated plasma
lactate.
[0400] Variant TK2 syndromes include spinal muscular atrophy syndrome, rigid
spine syndrome, and severe myopathy with motor regression.
Mitochondrial DNA Depletion Syndrome-3 (MTSPS3)
[0401] Mitochondrial DNA Depletion Syndrome-3, also known as hepatocerebral
syndrome, is an autosomal recessive disorder caused by homozygous or compound
heterozygous mutations in the nuclear-encoded DGUOK gene. MTSPS3 is
characterized by onset in infancy of progressive liver failure and neurologic
abnormalities, hypoglycemia, and increased lactate in body fluids. Affected
tissues
show both decreased activity of the mtDNA-encoded respiratory chain complexes
(I,
III, IV, and V) and mtDNA depletion. Clinical symptoms include weakness,
hypotonia, lactic acidosis, elevated serum creatine kinase, renal dysfunction,
and
ragged red fibers.
Mitochondrial Encephalopathy Lactic Acidosis Stroke (MELAS)
[0402] MELAS Syndrome, comprising mitochondrial myopathy, encephalopathy,
lactic acidosis, and stroke-like episodes, is a genetically heterogeneous
mitochondrial
disorder with a variable clinical phenotype. MELAS Syndrome can be caused by
mutations in several genes, including POLG, MTTL1, MTTQ, MTTH, MTTK,
MTTF, MTTC, MTTS1, MTTV, MTTQ, MTND1, MTND3, MTND5, MTND6,
MTCOI, cytochrome b, and MTTS2, with mutations in MTTL1 accounting for the
majority of MELAS cases. In particular, it is estimated that approximately 80%
of
MELAS patients have an A3243G point mutation in the MTTL1 gene. The disorder
is accompanied by features of central nervous system involvement, including
seizures,
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hemiparesis, hemianopsia, cortical blindness, and episodic vomiting. Primary
causes
of death are cardiopulmonary failure, status epilepticus, and pulmonary
disease.
[0403] Clinical symptoms include distal arthrogryposis, headache and vomiting,
sensorineural hearing loss, seizures, loss of consciousness, dementia, mental
retardation, focal events (strokes), cortical visual defects, hemiplegia,
neuronal
hyperexcitability, basal ganglia calcifications, weakness, exercise
intolerance, ptosis,
external ophthalmoplegia, gait disorder, paresthesias and numbness, reduced
tendon
reflexes, sensory neuropathy, chorea, Parkinsonism, ataxia, pigmentary
retinopathy,
macular dystrophy, optic atrophy, visual field defects, hypertelorism,
hypertrophic
cardiomyopathy, left ventricular noncompaction, conduction defects (such as
Wolff-
Parkinson-White), hypertension, short stature, maternally inherited diabetes
(MIDD),
pancreatitis, constipation, diarrhea, intestinal pseudoobstruction (ileus),
nausea,
dysphagia, abdominal pain, epigastralgia, sialoadenitis focal segmental
glomerulosclerosis, renal cysts, tubular dysfunction, nephrotic syndrome,
multihormonal hypopituitarism, Hashimoto thyroiditis, goiter,
Hypoparathyroidism,
Addison's disease, ovarian failure, miscarriage, lipoma, Atopic dermatitis,
local
melanoderma, asymmetric vascular dilatation, lactic acidosis, white matter
lesions,
respiratory chain dysfunction, ragged red fibers, cortical atrophy, focal
necrosis,
Purkinje dendrite cactus formations with increased mitochondria, and
mitochondrial
capillary angiopathy.
[0404] Other MTTF disorders include myoglobinuria, MERRF, camptocormia,
seizures, and ataxia.
Mvopathy and External Ophthalmoplegia; Neuropathy; Gastro-Intestinal;
Encephalopathy (MNGIE)
[0405] Mitochondrial DNA Depletion Syndrome-1 (MTDPS1), which manifests as
a neurogastrointestinal encephalopathy (MNGIE), is caused by homozygous or
compound heterozygous mutations in the nuclear-encoded thymidine phosphorylase
gene (TYMP). TYMP catalyzes phosphorolysis of thymidine to thymine and
deoxyribose 1-phosphate, and plays a role in homeostasis of cellular
nucleotide pools.
Mitochondrial DNA Depletion Syndrome-1 (MTDPS1) is an autosomal recessive
progressive multisystem disorder clinically characterized by onset between the
second
and fifth decades of life of ptosis, progressive external ophthalmoplegia
(PEO), retinal
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degeneration, optic atrophy, gastrointestinal dysmotility (often
pseudoobstruction,
gastroparesis, obstipation, malabsorption, diarrhea, abdominal pain & cramps,
nausea
& vomiting), borborygmi, early satiety, cachexia, thin body habitus, short
stature,
diffuse leukoencephalopathy, myopathy (proximal weakness, exercise
intolerance),
peripheral neuropathy (sensory loss/pain/ataxia, weakness, tendon reflexes
absent,
axonal loss, demyelination), hearing loss, cognitive impairment or dementia,
seizures,
headaches, and mitochondrial dysfunction. Mitochondrial DNA abnormalities can
include depletion, deletion, and point mutations. MNGIE usually presents at <
20
years of age. Additional symptoms include incomplete right bundle branch block
(cardiac defect), diabetes or glucose intolerance, amylase increase, exocrine
insufficiency, neoplasms, lactic acidosis, elevated plasma thymidine levels,
elevated
plasma deoxyuridine & deoxythymidine levels, tetany, cardiac arrhythmia, high
CSF
protein, brain atrophy, mitochondrial changes in muscle fibers and neurogenic
changes.
[0406] Partial loss of thymidine phosphorylase activity can result in a
variant
MNGIE disorder that manifests around the 5th decade of life. Clinical symptoms
include ophthalmoplegia, ptosis, gastrointestinal features, and axon loss with
or
without demyelination.
[0407] Mitochondrial DNA Depletion Syndrome-4B (MTDPS4B), which manifests
as a neurogastrointestinal encephalopathy (MNGIE), is caused by compound
heterozygous mutations in the nuclear-encoded POLG gene. Mitochondrial DNA
Depletion Syndrome-4B is an autosomal recessive progressive multisystem
disorder
clinically characterized by chronic gastrointestinal dysmotility and
pseudoobstruction,
cachexia, progressive external ophthalmoplegia (PEO), axonal sensory ataxic
neuropathy, and muscle weakness.
[0408] Another MNGIE variant is MNGIM Syndrome without encephalopathy,
which is not associated with mutations in thymidine phosphorylase or dNT-2.
Clinical features include gastrointestinal malabsorption, diarrhea,
borborygmi,
abdominal pain, GI pseudo-obstruction, weight loss, ophthalmoplegia, ptosis,
weakness, cachexia, polyneuropathy (pain, gait disorder, sensory ataxia,
axonal loss),
high CSF protein, ragged red fibers, and reduced Complex I¨TV activities.
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[0409] Mutations in MTTW can manifest as a neurogastrointestinal
encephalopathy
(MNGIE). Patients present at 1 year of age with recurrent vomiting and failure
to
thrive. Leg discomfort, cognitive regression, seizures, muscle wasting, and
incontinence manifest later during childhood. Other features include
sensorineural
deafness, ptosis, ophthalmoplegia, pigmentary retinopathy, constricted visual
fields,
short stature, feeding difficulties with constipation, colitis and diarrhea,
high lactate
levels in blood and CSF, brain atrophy, and periventricular white matter
changes.
Muscle biopsies show COX-negative fibers and low activity of Complexes I and
IV.
[0410] Mutations in MTTV can manifest as a neurogastrointestinal
encephalopathy
(MNGIE). Age of onset is usually during early childhood. Clinical symptoms
include cachexia, headache, gastrointestinal motility problems (Ileus,
Abdominal
pain; Megacolon), hearing loss, developmental delay, high serum lactate, COX-
negative fibers and low activity of complexes I and IV. Disruption of MTTV
function
can also lead to Ataxia, Seizures & Hearing loss, and Learning difficulties,
Hemiplegia & Movement disorder.
Menkes Disease, Occipital Horn Syndrome and X-linked Distal Spinal Muscular
Atrophy-3
[0411] Menkes disease is an X-linked recessive disorder characterized by
generalized copper deficiency and is caused by mutations in the ATP7A gene.
Menkes disease usually manifests at birth and its clinical features result
from the
dysfunction of several copper-dependent enzymes. Clinical symptoms include
seizures, pili torti, bladder diverticula, skin laxity, occipital exostoses,
chronic
diarrhea, acute onset of severe intra-abdominal bleeding, hemorrhagic shock,
multiple
fractures, hypoglycemia, hypothermia, feeding difficulties, hair with an
abnormal
texture, low serum copper and ceruloplasmin levels, subdural hematomas, high
arched
palate, wormian bones in the lambdoid suture of the occipital region,
developmental
delay, and speech loss.
[0412] Occipital Horn Syndrome (OHS) is caused by mutations in the gene
encoding Cu(2)-transporting ATPase, alpha polypeptide (ATP7A). Occipital Horn
Syndrome is a rare connective tissue disorder characterized by hyperelastic
and
bruisable skin, hernias, bladder diverticula, hyperextensible joints,
varicosities, and
multiple skeletal abnormalities. The disorder is sometimes accompanied by mild
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neurologic impairment, and bony abnormalities of the occiput are a common
feature,
giving rise to the name. Clinical features include severe congenital cutis
laxa,
extremely loose skin, with truncal folds and sagging facial skin, pectus
excavatum,
craniotabes, stridor, sparse coarse hair, fragmented elastin fibers, and low
serum
copper.
[0413] X-linked distal spinal muscular atrophy-3 (SMAX3) is caused by
mutations
in the copper transport gene ATP7A and is characterized by spinal muscular
atrophy
affecting both the upper and lower limbs. Onset ranges from 1 to 10 years of
age.
Clinical symptoms include foot deformity (pes cavus or pes varus), gait
instability,
distal motor weakness and atrophy.
Methemoglobinemia
[0414] Methemoglobinemia is an autosomal recessive disorder characterized by
decreased oxygen carrying capacity of the blood, resulting in cyanosis and
hypoxia.
Methemoglobinemia is associated with mutations in the CYB5R3 gene, which
encodes cytochrome b5 reductase-3, an enzyme localized to the mitochondrial
outer
membrane where it catalyzes the transfer of reducing equivalents from NADH to
cytochrome b5. There are two types of methemoglobin reductase deficiency. In
type
I, the defect affects the soluble isoform of CYB5R3, which is expressed in
erythrocytes and functions to reduce methemoglobin to hemoglobin. In type II,
the
defect affects both soluble and microsomal isoforms of the enzyme, which play
a role
in physiologic processes including cholesterol biosynthesis and fatty acid
elongation
and desaturation. Type II methemoglobinemia is associated with mental
deficiency
and other neurologic symptoms.
Myoclonic Epilepsy Ragged Red Fibers (MERRF)
[0415] MERRF Syndrome represents a maternally-inherited myopathy that can be
produced by mutations in more than 1 mitochondrial gene, e.g., MTTK, MTTL1,
MTTH, MTTS1, MTTS2, MTTF etc. Features of the MERRF Syndrome have also
been associated with mutations in the MTND5 gene.
[0416] Clinical features include myoclonus, epilepsy, cardiomyopathy, ataxia,
gait
disorder, dementia, optic atrophy, distal sensory loss, hearing loss,
weakness, muscle
pain, cramps, fatigue, short stature, lipomata, ragged red fibers, vacuoles in
small
fibers, and reduced Complex I, III and IV activity.
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[0417] Other MTTK syndromes include cardiomyopathy, progressive external
ophthalmoplegia with myoclonus, deafness and diabetes (DD), multiple symmetric
lipomatosis, Leigh Syndrome, MELAS, MNGIE, Myopathy with Episodic high
Creatine Kinase (MIMECK), Parkinson syndrome neuropathy and myopathy.
Clinical features of MIMECK include weakness, dysphagia, and episodic
myalgias.
[0418] Other MTTS1 disorders include MELAS, Epilepsia Partialis Continua, HAM
Syndrome, myopathy, encephalopathy with cytochrome c oxidase deficiency,
Myoclonus, epilepsy, cerebellar ataxia & progressive hearing loss, exercise
intolerance, keratoderma, palmoplantar, with deafness, and sensorineural
hearing loss.
[0419] Mutations in MTTP can also result in myoclonic epilepsy, myopathy,
sensorineural deafness, cerebellar ataxia, and pigmentary retinopathy.
Myoglobinuria
[0420] Myoglobinuria can arise as a result of malignant hyperthermia
syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
mitochondrial disorders, certain drugs and toxins, hypokalemic myopathy and
rhabdomyolysis, muscle trauma, ischemia, infections, or immune myopathy. Other
disorders associated with occasional myoglobinuria include Brody myopathy,
cylindrical spiral (myofilamentous) myopathy, familial recurrent
rhabdomyolysis,
fingerprint body disease, G6PDH deficiency, hypokalemic periodic paralysis,
Marinesco-Sjogren Syndrome, myoadenylate deaminase deficiency, myotonias,
multicore disease, Native American Myopathy, Schwartz-Jampel Syndrome
(chondrodystrophic myotonia), sickle cell anemia, and several muscular
dystrophies
including Duchenne and Becker muscular dystrophy, Miyoshi myopathy,
sacroglycanopathies, limb-girdle muscular dystrophy-dystroglycanopathy type
C5,
and limb-girdle muscular dystrophy-2L.
1. Malignant Hyperthermia Syndromes
[0421] Malignant hyperthermia syndromes leading to myoglobinuria can include
central core disease, King-Denborough Syndrome, also known as malignant
hyperthermia susceptibility 1 (MHS1), malignant hyperthermia susceptibility 2
(MHS2) malignant hyperthermia susceptibility 3 (MHS3), malignant hyperthermia
susceptibility 4 (MHS4), malignant hyperthermia susceptibility 5 (MHS5),
malignant
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hyperthermia susceptibility 6 (MHS6), and other disorders associated with
malignant
hyperthermia susceptibility, including Duchenne and Becker muscular
dystrophies,
myotonic dystrophy, myotonia congenital, Schwartz-Jampel Syndrome, and
Satoyoshi
Syndrome.
2. Glycogen Metabolic Disorders
[0422] Glycogen metabolic disorders leading to myoglobinuria can include
McArdle disease, also known as glycogen storage disease type V (GSD5), Tarui
disease, also known as glycogen storage disease VII (GSD7), and other
glycogenoses,
including aldolase A deficiency, also known as glycogen storage disease XII
(GSD12), lactate dehydrogenase A deficiency, also known as glycogen storage
disease XI (GSD11), phosphoglycerate kinase-1 deficiency, phosphoglycerate
mutase
deficiency, also known as glycogen storage disease X (GSD10), phosphorylase
kinase
deficiency of liver and muscle, also known as glycogen storage disease IXb
(GSD9B),
Forbes disease, also known as glycogen storage disease III (GSD3) or glycogen
debrancher deficiency, and 0-enolase deficiency, also known as glycogen
storage
disease XIII (GSD13).
3. Fatty Acid Oxidation and Lipid Metabolism Disorders
[0423] Fatty acid oxidation and lipid metabolism disorders leading to
myoglobinuria can include carnitine palmitoyltransferase II (CPT II)
deficiency,
acyl-CoA dehydrogenase deficiencies, a-methylacyl-CoA racemase (AMACR)
deficiency, electron transfer flavoprotein disorders, ketoacyl CoA thiolase
deficiency,
recurrent acute myoglobinuria, also known as recurrent rhabdomyolysis in
childhood,
and trifunctional enzyme deficiency, also known as long chain 3-hydroxyacyl-
coenzyme A dehydrogenase deficiency (LCHAD) deficiency.
[0424] Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency is a
rare autosomal recessive condition that prevents the body from converting
certain fats
to energy, particularly during periods without food (fasting). Mutations in
the
HADHA gene cause LCHAD deficiency. Signs and symptoms of LCHAD
deficiency typically appear during infancy or early childhood and can include
feeding
difficulties, lack of energy (lethargy), low blood sugar (hypoglycemia), weak
muscle
tone (hypotonia), liver problems, and abnormalities in the light-sensitive
tissue at the
back of the eye (retina). Later in childhood, people with this condition may
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experience muscle pain, breakdown of muscle tissue, and a loss of sensation in
their
arms and legs (peripheral neuropathy). Individuals with LCHAD deficiency are
also
at risk for serious heart problems, breathing difficulties, coma, and sudden
death.
Problems related to LCHAD deficiency can be triggered by periods of fasting or
by
illnesses such as viral infections.
[0425] Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is an
autosomal recessive condition caused by mutations in the ACADM gene. Signs and
symptoms of MCAD deficiency typically appear during infancy or early childhood
and can include vomiting, lack of energy (lethargy), and low blood sugar
(hypoglycemia). In rare cases, symptoms of this disorder first appear during
adulthood. People with MCAD deficiency are at risk for serious complications
such
as seizures, breathing difficulties, liver problems, brain damage, coma, and
sudden
death.
[0426] Long-chain acyl-CoA dehydrogenase (LCAD) deficiency is caused by
mutations in the ACADL gene. Subjects with LCAD can present with SIDS,
hypoglycemia, hepatomegaly, myopathy, Reye syndrome, and cardiomyopathy. The
plasma acylcarnitine profile exhibits elevated long chain acyl-carnitine
esters. Urine
organic acids typically show elevations of dicarboxylic acids.
4. Mitochondrial Disorders
[0427] Mitochondrial disorders leading to myoglobinuria can include cytochrome
c
oxidase (COX) deficiencies, cytochrome b deficiency, mitochondrial myopathies,
including coenzyme Q10 deficiency, myopathy with lactic acidosis, also known
as
Swedish type myopathy with exercise intolerance, dihydrolipoamide
dehydrogenase
(DLD) deficiency, mutations in the DGUOK gene, which encodes mitochondrial
deoxyguanosine kinase, and iron-sulfur complex disorders, including those
associated
with mutations in one or more of the following genes: ISCU, FDX1L, NFUl,
BOLA3, NUBPL, IBA57, LYRM4, and LYRM7.
5. Medication-, Drug- or Toxin-induced Myoglobinuria
[0428] Certain medications such as amiodarone, arsenic trioxide, emetine, E-
amino
caproic acid, lipid lowering agents such as clofibrate and statins, isoniazid,
lamotrigrine, antipsychotics, nicotinic acid, pentamidine, propofol, proton
pump
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inhibitors, selective serotonin reuptake inhibitors, irinotican, temazepam,
valproate,
vasopressin, and zidovudine are associated with the development of
myoglobinuria.
Drugs and toxins associated with the development of myoglobinuria include
cocaine,
heroin, snake venom, insect venom, blowpipe dart poison, and drugs and toxins
that
produce muscle overactivity, including amphetamines, hemlock, loxpapine, LSD,
mercuric chloride, phencyclidine, strychnine, tetanus toxin, and terbutaline.
The
ingestion of certain toxins including ethanol, monensin, chromium picolinate,
methylenedioxypyrovalerone, mephedrone, phencyclidine, and those present in
Buffalo fish, burbot, mushrooms (Amanita phalloides, Trichloma equestre),
kidney
beans, and peanut oil may also cause myoglobinuria.
[0429] Other drugs and toxins associated with the development of myoglobinuria
include acetaminophen, amoxapine, anticholinergics, azathioprine, baclofen,
barbiturates, benzodiazepines, butyrophenones, caffeine, chloral hydrate,
chlorpromazine, colchicine, corticosteroids, daptomycin, diphenhydramine,
doxylamine, ephedra, fenfluramine, glutethimide, hydroxyzine, ketamine,
lysergic
acid diethylamide, methanol, minocycline, morphine, phencyclidine,
phenothiazines,
phentermine phenytoin, quinolones, salicylate, serotonin antagonists,
succinylcholine,
sunitinib sympathomimetics, theophylline, trimethoprim-sulfamethoxazole, and
vincristine.
6. Hypokalemic Myopathy and Rhabdomyolysis
[0430] Hypokalemic myopathy and rhabdomyolysis can be of a pharmacologic or
toxic origin. Hypokalemic myopathy and rhabdomyolysis having a pharmacologic
origin is associated with diuretics and laxatives, such as thiazides,
amphotericin,
lithium, gossypol, methylxanthines, and laxative abuse. Toxins associated with
the
development of hypokalemic myopathy and rhabdomyolysis include glycyrrhizic
acid, glycyrrhetinic acid, barium, ethanol, cottonseed oil, and volatile
substances, such
as toluene.
7. Muscle trauma
[0431] Muscle trauma leading to myoglobinuria can be acute, such as that
associated with physical trauma, or chronic, such as that associated with
alcohol,
opiates, and sedatives. Muscle trauma can also be caused by overactivity due
to
exercise, drugs and toxins producing muscle overactivity, hyperthermia, or
seizures.
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Muscle trauma can also be caused by compartment syndromes and temperature
alterations associated with heat stroke, malignant hyperthermia, neuroleptic
malignant
syndrome, burns, or hypothermia.
8. Ischemia
[0432] Ischemia leading to myoglobinuria can be caused by vascular occlusion,
hemangioma steal syndrome, sickle cell trait, cocaine, calciphylaxis,
compartment
syndrome, carbon monoxide exposure, or cyanide poisoning.
9. Infections
[0433] Infections associated with myoglobinuria include viral infections such
as
influenza A and B, coxsackie virus, herpes, adenovirus, and HIV-1; bacterial
infections including Streptococci, Salmonella, Staphylococci, typhoid fever,
Legionella, Clostridia, and E. coli; Mediterranean tick typhus; tick-borne
infections
such as ehrlichiosis, anaplasmosis, baesiosis, Lyme disease, and Rocky
Mountain
spotted fever; and hyperthermia-related infections.
10. Immune myopathy
[0434] Immune myopathies associated with myoglobinuria include polymyositis
and dermatomyositis.
Myopathy, Lactic Acidosis and Sideroblastic Anemia (MLASA)
[0435] Myopathy, lactic acidosis, and sideroblastic anemia (MLASA) is a rare
autosomal recessive oxidative phosphorylation disorder specific to skeletal
muscle
and bone marrow. Myopathy, lactic acidosis, and sideroblastic anemia-1
(MLASA1)
can be caused by homozygous mutations in the PUS1, which converts uridine into
pseudouridine after the nucleotide has been incorporated into RNA.
Pseudouridine
may have a functional role in tRNAs and may assist in the peptidyl transfer
reaction
of rRNAs. MLASA1 usually presents in children and teens and is characterized
by
progressive weakness, exercise intolerance, fatigue, nausea and vomiting,
ptosis, short
stature, sideroblastic anemia, lactic acidosis and reduced mitochondrial
oxidative
enzyme activities.
[0436] Myopathy, lactic acidosis, and sideroblastic anemia-2 (MLASA2) is an
autosomal recessive disorder of the mitochondrial respiratory chain that is
caused by
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homozygous mutations in the aminoacyl-tRNA synthetase gene YARS2. The
disorder shows marked phenotypic variability: some patients have a severe
multisystem disorder from infancy, including cardiomyopathy and respiratory
insufficiency resulting in early death, whereas others present in the second
or third
decade of life with sideroblastic anemia and mild muscle weakness. Additional
clinical features include dysphagia, weakness, exercise intolerance, short
stature, high
serum lactate, reduced COX activity, and reduced Complex I, III and IV
activity.
Infantile Mitochondrial Myopathy due to Reversible COX Deficiency (MMIT)
[0437] Infantile mitochondrial myopathy due to reversible COX deficiency is a
rare
mitochondrial disorder characterized by onset in infancy of severe hypotonia
and
generalized muscle weakness associated with lactic acidosis, but is
distinguished from
other mitochondrial disorders in that affected individuals recover
spontaneously after
1 year of age. MMIT is caused by mutations in the MTTE gene, which is encoded
by
the mitochondrial genome.
[0438] Clinical features include muscle weakness, hypotonia, respiratory
failure,
dysphagia, ophthalmoplegia, macroglossia, neuropathy, seizures,
encephalopathy,
hepatomegaly, pneumonia, lactic acidosis, delayed myelination, high serum
creatine
kinase, ragged red fibers, reduced COX activity, reduced Complex I activity,
increased lipid or glycogen in muscle fibers, muscle degeneration,
inflammation, lipid
droplets in fibers, and mtDNA reduction.
[0439] Variant MTTE syndromes include mitochondrial myopathy with diabetes
mellitus, diabetes-deafness syndrome, LHON, Mitochondrial myopathy with
respiratory failure, MELAS/LHON/DEAF, progressive encephalopathy,
encephalomyopathy with retinopathy, leukoencephalopathy and exercise
intolerance.
[0440] Additionally, certain MTTE mutations can lead to at least one or more
symptoms such as myopathy, ataxia, lactic acidosis, high serum creatine
kinase,
SDH+ & COX negative muscle fibers, reduced Complexes I, III & IV activity,
retinopathy, severe myopathy with respiratory failure, ptosis, PEO, pigmentary
retinopathy, migraines, life-long exercise intolerance and leukodystrophy.
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Specific Sporadic Mitochondrial Myopathy Syndromes
1. Myopathy, Exercise Intolerance, Encephalopathy, Lactic acidemia
[0441] Cytochrome c oxidase subunit III (COIII or MTC03) is 1 of 3
mitochondrial
DNA (mtDNA) encoded subunits (MTC01, MTCO2, MTC03) of respiratory
Complex IV. Complex IV is located within the mitochondrial inner membrane and
is
the third and final enzyme of the electron transport chain of mitochondrial
oxidative
phosphorylation. It collects electrons from ferrocytochrome c (reduced
cytochrome c)
and transfers then to oxygen to give water. The energy released is to
transport protons
across the mitochondrial inner membrane. Complex IV is composed of 13
polypeptides. Subunits I, II, and III (MTC01, MTCO2, MTC03) are encoded by the
mtDNA while subunits VI, Va, Vb, VIa, VIb, VIc, VIIa, VIIb, Vile, and VIII are
nuclear encoded. Subunits VIa, VIIa, and VIII have systemic as well as heart
muscle
iso forms.
[0442] Mutations in MTC03 can result in Myopathy, Exercise intolerance,
Encephalopathy, Lactic acidemia Syndrome, which usually manifests between 4 to
20
years of age. Clinical symptoms include weakness, myalgia, fatigue,
myoglobinuria,
encephalopathy, migraine, spastic paraparesis, mental retardation,
ophthalmoplegia,
high serum lactate, COX deficiency, SDH positive muscle fibers, and lipid
accumulation in type I fibers.
[0443] Mutations in MTC03 can also result in isolated myopathy (characterized
by
weakness, COX deficiency, persistent ragged red fibers), myoglobinuria,
maternally
inherited myopathies, MELAS-like disorder, Leigh-like disorder, and
nonarteritic
ischemic optic neuropathy (NAION)-Myoclonic epilepsy.
2. M_yoglobinuria & Exercise Intolerance
[0444] Mutations in MTC01 can result in Myoglobinuria and exercise
intolerance,
which usually manifests at childhood. Clinical symptoms include exercise
intolerance, myoglobinuria, COX deficiency, and defects in Complex I & III.
Other
MTC01 syndromes include acquired sideroblastic anemia; Deafness, Ataxia,
Blindness, Myopathy; epilepsy partialis continua; motor neuron disease; LHON;
Myopathy, Cardiomyopathy, Stroke; MELAS-like Syndrome.
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3. Exercise Intolerance, Proximal Weakness Myoglobinuria
[0445] Cytochrome b (MTCYB) is the only mitochondrial DNA (mtDNA) encoded
subunit of respiratory Complex III (ubiquinol:ferrocytochrome c
oxidoreductase, or
cytochrome bcl, complex). Complex III is located within the mitochondrial
inner
membrane and is the second enzyme in the electron transport chain of
mitochondrial
oxidative phosphorylation. It catalyzes the transfer of electrons from
ubiquinol
(reduced Coenzyme Q10) to cytochrome c and utilizes the energy to translocate
protons from inside the mitochondrial inner membrane to outside.
[0446] Disruption of MTCYB function can result in exercise intolerance,
proximal
weakness myoglobinuria syndrome, which manifests during childhood. Symptoms
include sensation of cramps, myalgias or fatigue, weakness, myoglobinuria,
septo-
optic dysplasia, retardation, encephalopathy, seizures, high serum lactate,
myopathy,
deficient Complex III activity, and ragged red fibers.
[0447] Mutations in MTCYB can lead to Encephalopathy & Seizures Syndrome,
which usually presents at 9 to 13 years of age. Clinical features include
exercise
intolerance, lactic acidosis, encephalopathy, poor balance, seizures, visual
hallucinations, depression, emotional lability, and ragged red fibers.
[0448] Other variant disorders caused by mutations in MTCYB include septo-
optic
dysplasia (characterized by mental retardation, delayed walking, exercise
intolerance,
retinitis pigmentosa, optic atrophy, hypertrophic cardiomyopathy, Wolff-
Parkinson-
White, lactic acidosis, and cerebellar hypoplasia), Familial Myalgia Syndrome,
Exercise intolerance, LHON, colon cancer, LVNC, MELAS, Parkinsonism, obesity,
and Migraine, Epilepsy, Polyneuropathy, Stroke-like episodes.
4. Exercise Intolerance Mild Weakness
[0449] Mutations in several mitochondrial genes such as MTTW, Cytochrome
b (Complex III), MTND1 (Complex I), MTND2 (Complex I), and MTND4 (Complex
I) can cause exercise intolerance with or without mild weakness, which
manifests at
childhood. Additional clinical features include dyspnea, tachycardia, high
serum
lactate, and ragged red fibers.
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5. Myopathy Exercise Intolerance, Growth or CNS disorder
[0450] Mutations in MTTM can result in Myopathy with or without Exercise
intolerance, Growth or CNS disorders, which usually manifests at 10 to 56
years of
age. Clinical symptoms include myopathy, proximal and distal weakness,
exercise
intolerance, muscle atrophy, ptosis, reduced tendon reflexes, growth
retardation,
mental retardation, lactic acidosis, high serum Creatine Kinase, ragged red
fibers,
COX deficiency, muscular dystrophy, cortical atrophy, and myelomalacia. Other
variant MTTM syndromes include Exercise intolerance, Autoimmune
polyendocrinopathy and Lactic acidosis.
6. Myopathy with Episodic High Creatine Kinase (MIMECK)
[0451] Mutations in MTTK can result in Myopathy with Episodic high Creatine
Kinase (MIMECK), which usually manifests between the ages of 15 to 69 years.
Clinical features include weakness, dysphagia, myalgias, and episodic high
serum
Creatine Kinase.
Maternally-Inherited Mitochondrial Myopathies
[0452] Maternally-inherited mitochondrial myopathies can be caused by
mutations
in Cytochrome c Oxidase, Subunit II (COX II or MTCO2). Myopathy usually
manifests in children and teens. Clinical features include weakness, fatigue
and
exercise intolerance, rhabdomyolysis, ataxia, retinopathy, optic atrophy,
reduction in
COX activity, lipid in type I fibers, cataracts, hearing loss, cardiac
arrhythmia,
depression, short stature, lactic acidosis, elevated serum or CSF lactate and
mitochondrial proliferation.
[0453] Mutations in MTTS1 can cause Myopathy, Deafness & CNS disorders that
usually manifest at 8 years of age. Clinical features include weakness or
contractures,
fatigue, sensorineural deafness, ataxia, cognitive impairment, optic atrophy,
axonal
sensory neuropathy, high serum and CSF lactate, mitochondrial proliferation,
COX-
fibers, and reduced Complex I & IV activity.
[0454] Mutations in MTTW can cause Myopathy, Ptosis & Dysphonia, which
usually manifests at 50 years of age. Clinical features include ptosis,
weakness,
fatigue, SDH+ and COX negative muscle fibers, and cytochrome c oxidase
reduction.
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[0455] Mutations in MTTE can cause Myopathy, Diabetes & CNS disorders, which
usually manifest in teens or adults. Clinical features include fatigue,
weakness,
orbicularis oculi, respiratory failure, FSH dystrophy, fatigue, diabetes,
polyneuropathy, cerebellar ataxia, nystagmus, congenital encephalopathy,
endomysial
fibrosis, mitochondrial proliferation, COX negative muscle fibers, reduced
Complex I
& IV activity, and focal COX reductions in cardiac muscle.
Autosomal Recessive Mitochondrial M_yopathies
1. Myopathy with Lactic Acidosis
[0456] Myopathy with lactic acidosis, also known as Swedish type myopathy with
exercise intolerance, is caused by homozygous or compound heterozygous
mutations
in the ISCU gene, encoding the iron-sulfur cluster scaffold protein, on
chromosome
12q24. Hereditary myopathy with lactic acidosis is an autosomal recessive
muscular
disorder characterized by childhood onset of exercise intolerance with muscle
tenderness, cramping, dyspnea, and palpitations. Clinical features include
fatigue,
shortness of breath, tachycardia, weakness, lactic acidosis, rhabdomyolysis,
muscle
swelling, myalgias, cardiac hypertrophy, SDH deficiency, abnormality of muscle
mitochondrial iron-sulfur cluster-containing proteins, high serum lactate,
reduced
COX expression, and mitochondrial inclusions. Disruption of ISCU function can
also
result in Myopathy with Myoglobinuria.
[0457] Iron-sulfur cluster disorders can also arise as a result of mutations
in
FDX1L, Glutaredoxin 5, NFUl, BOLA3, NUBPL, IBA57, LYRM4 and LYRM7.
2. Myopathy + Rhabdomyolysis
[0458] Myopathy with rhabdomyolysis is caused by mutations in Ferredoxin 1-
like
protein (FDX1L), which plays a role in Fe-S cluster biogenesis. Clinical
symptoms
include weakness, dyspnea, myoglobinuria, fatigue, reduced Complex I, II &
III activities, reduced aconitase activity, high citrate synthase, high
lactate, 3-methyl
glutaconic acid, ketones & Krebs cycle metabolites.
3. Myopathy + Cataracts & Combined Respiratory Chain Defects
[0459] Myopathy with cataract and combined respiratory chain deficiency can be
caused by mutations in the GFER gene, which plays a role in the
mitochondrial disulfide relay system. Clinical features include reduced
Complex I, II,
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and IV activity, accumulation of multiple mtDNA deletions, cataracts,
hypotonia,
developmental delay, muscle smallness, reduced tendon reflexes, sensorineural
hearing loss, SDH+ and COX negative muscle fibers, high serum lactate, low
serum
fen-inn, and high serum amylase.
4. Myopathy with Abnormal Mitochondrial Translation
[0460] Myopathy with abnormal mitochondrial translation is an autosomal
disorder
that manifests during childhood. Clinical symptoms include weakness,
fatiguability,
hypotonia, ptosis, ophthalmoplegia, short stature, sideroblastic anemia,
mitochondrial
proliferation in muscle fibers, reduced COX activity, reduced Complex I, II,
III and
IV activity, and mitochondrial translation defects.
5. Fatigue & Exercise Intolerance
[0461] Fatigue Syndrome is caused by homozygous or compound heterozygous
mutations in the ACAD9 gene, which encodes a protein that catalyzes the
initial rate-
limiting step in 0-oxidation of fatty acyl-CoA. ACAD9 deficiency is an
autosomal
recessive multisystemic disorder characterized by infantile onset of acute
metabolic
acidosis, hypertrophic cardiomyopathy, and muscle weakness associated with a
deficiency of mitochondrial complex I activity in muscle, liver, and
fibroblasts.
Clinical features include exercise intolerance, urge to vomit, sense of mental
slowness, reduced Complex I activity, high serum lactate. Episodic hepatic
dysfunction is also present in some variants of the syndrome.
6. Myopathy with Extrapyramidal Movement Disorders (MPXPS)
[0462] Myopathy with extrapyramidal signs is an autosomal recessive disorder
characterized by early childhood onset of proximal muscle weakness and
learning
disabilities. While the muscle weakness is static, most patients develop
progressive
extrapyramidal signs that may become disabling. Myopathy with extrapyramidal
signs (MPXPS) is caused by homozygous mutations in the MICUl gene, which plays
a role in mitochondrial Ca2+ uptake. Clinical features include chorea, tremor,
dystonia, orofacial dyskinesia, ataxia, microcephaly, ophthalmoplegia, ptosis,
optic
atrophy, and peripheral neuropathy.
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7. Glutaric aciduria II (MADD)
[0463] MADD, also known as glutaric acidemia II or glutaric aciduria II, can
be
caused by mutations in at least 3 different genes: ETFA, ETFB, and ETFDH.
These
genes are all involved in electron transfer in the mitochondrial respiratory
chain. The
disorders resulting from defects in these 3 genes are referred to as glutaric
acidemia
IIA, IIB, and TIC, respectively, although there appears to be no difference in
the
clinical phenotypes.
[0464] Glutaric aciduria II (GA II) is an autosomal recessively inherited
disorder of
fatty acid, amino acid, and choline metabolism. It differs from GA I in that
multiple
acyl-CoA dehydrogenase deficiencies result in large excretion not only of
glutaric
acid, but also of lactic, ethylmalonic, butyric, isobutyric, 2-methyl-butyric,
and
isovaleric acids. GA II results from deficiency of any 1 of 3 molecules: the
alpha
(ETFA) and beta (ETFB) subunits of electron transfer flavoprotein, and
electron
transfer flavoprotein dehydrogenase (ETFDH).
[0465] The heterogeneous clinical features of patients with MADD fall into 3
classes: a neonatal-onset form with congenital anomalies (type I), a neonatal-
onset
form without congenital anomalies (type II), and a late-onset form (type III).
The
neonatal-onset forms are usually fatal and are characterized by severe
nonketotic
hypoglycemia, metabolic acidosis, multisystem involvement, and excretion of
large
amounts of fatty acid- and amino acid-derived metabolites. Symptoms and age at
presentation of late-onset MADD are highly variable and characterized by
recurrent
episodes of lethargy, vomiting, hypoglycemia, metabolic acidosis, and
hepatomegaly
often preceded by metabolic stress. Muscle involvement in the form of pain,
weakness, and lipid storage myopathy also occurs. The organic aciduria in
patients
with the late-onset form of MADD is often intermittent and only evident during
periods of illness or catabolic stress.
8. Coenzyme 010 Deficiency
[0466] Primary C0Q10 deficiency is a rare, clinically heterogeneous autosomal
recessive disorder caused by mutation in any of the genes encoding proteins
directly
involved in the synthesis of coenzyme Q. Coenzyme Q10 (CoQ10), or ubiquinone,
is
a mobile lipophilic electron carrier critical for electron transfer by the
mitochondrial
inner membrane respiratory chain.
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[0467] The disorder has been associated with 5 major phenotypes, but the
molecular
basis has not been determined in most patients with the disorder and there are
no clear
genotype/phenotype correlations. The phenotypes include an encephalomyopathic
form with seizures and ataxia; a multisystem infantile form with
encephalopathy,
cardiomyopathy and renal failure; a predominantly cerebellar form with ataxia
and
cerebellar atrophy; Leigh Syndrome with growth retardation; and an isolated
myopathic form.
[0468] Autosomal recessive forms of the disorder include COQ10D1, caused by
mutations in COQ2; COQ10D2, caused by mutations in the PDSS1 gene; COQ10D3,
caused by mutations in the PDSS2 gene; COQ10D4, caused by mutations in the
COQ8 gene (ADCK3); COQ10D5, caused by mutations in the COQ9 gene; and
COQ10D6, caused by mutations in the COQ6 gene.
[0469] Secondary C0Q10 deficiency has been reported in association with
glutaric
aciduria type TIC (MADD), caused by mutation in the ETFDH gene, and with
ataxia-
oculomotor apraxia syndrome-1 (A0A1), caused by mutation in the APTX gene.
Autosomal Dominant Mitochondrial Myopathy
[0470] Dominant mutations in coiled-coil-helix-coiled-coil-helix domain-
containing
protein 10 (CHCHD10) can lead to mitochondrial myopathy with exercise
intolerance, which usually manifests within the first decade of life. Clinical
features
include exercise intolerance, weakness in legs, arms, and face, restrictive
deficits in
pulmonary function, short stature, high serum lactate, high serum pyruvate,
ragged
red fibers, reduced cytochrome c oxidase (Complex IV) activity, and reduced
succinate cytochrome c reductase (Complex II & III) activity.
[0471] Other examples of autosomal dominant mitochondrial myopathies include
myopathy with focal depletion of mitochondria, mitochondrial DNA breakage
syndrome (PEO + Myopathy), LGMD1H, and lipid type mitochondrial myopathy.
Multiple Symmetric Lipomatosis (Madelung Syndrome)
[0472] Multiple symmetric lipomatosis (MSL) is a rare disorder characterized
by
the growth of uncapsulated masses of adipose tissue. It is associated with
high
ethanol intake and may be complicated by somatic and autonomic neuropathy and
by
the infiltration of the adipose tissue at the mediastinal level. MSL can arise
as a result
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of an autosomal dominant, mitochondrial, or sporadic mutation. Clinical
features
include multiple lipomas in the nape of the neck, supraclavicular and deltoid
regions,
full body lipomas, polyneuropathy, hyperuricemia, high triglycerides (VLDL,
chylomicrons), high HDL, and ragged red fibers.
N-acetylglutamate Synthase Deficiency
[0473] N-acetylglutamate synthase (NAGS) deficiency is an inborn error of
metabolism affecting ammonia detoxification in the urea cycle. N-
acetylglutamate
synthase is a mitochondrial enzyme that catalyzes the formation of N-
acetylglutamate
(NAG). NAG is an essential allosteric activator of carbamoylphosphate synthase
1
(CPS1), the first and rate-limiting enzyme in the urea cycle. Most NAGS genes
contain a C-terminus transferase domain in which the catalytic activity
resides and an
N-terminus kinase domain where arginine binds. Because CPS1 is inactive
without
NAG, the urea cycle function can be severely affected resulting in fatal
hyperammonemia in neonatal patients or at any later stage in life. Clinical
manifestations of NAGS deficiency include poor feeding, vomiting, altered
levels of
consciousness, seizures, and coma.
Neoplasms
[0474] Mutations in certain nuclear encoded mitochondrial genes can give rise
to
neoplasms, such as paraganglionoma, leiomyomatosis, renal cell cancer, and B-
cell
lymphoma. Paragangliomas, also referred to as 'glomus body tumors,' are tumors
derived from paraganglia located throughout the body. Nonchromaffin types
primarily serve as chemoreceptors (hence, the tumor name 'chemodectomas') and
are
located in the head and neck region (i.e., carotid body, jugular, vagal, and
tympanic
regions), whereas chromaffin types have endocrine activity, conventionally
referred to
as 'pheochromocytomas,' and are usually located below the head and neck (i.e.,
adrenal medulla and pre- and paravertebral thoracoabdominal regions). PGL can
manifest as nonchromaffin head and neck tumors only, adrenal and/or
extraadrenal
pheochromocytomas only, or a combination of the 2 types of tumors.
[0475] Familial paragangliomas-1 (PGL1) is caused by mutations in the SDHD
gene, which encodes the small subunit of cytochrome B in succinate-ubiquinone
oxidoreductase. PGL1 manifests as benign vascularized tumors in the head and
neck.
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[0476] Hereditary paragangliomas-2 (PGL2) is caused by mutations in the SDHAF2
gene, which encodes a protein necessary for flavination of SDHA. PGL1
manifests as
tumors in the head and neck, and especially the carotid body.
[0477] Hereditary paragangliomas-3 (PGL3) is caused by heterozygous mutations
in
the SDHC gene, which encodes subunit C of the succinate dehydrogenase complex.
PGL3 manifests as benign vascularized tumors in the head and neck.
[0478] Familial paragangliomas-4 (PGL4) is caused by heterozygous mutations in
the SDHB gene, which encodes the iron sulfur subunit of succinate
dehydrogenase.
Clinical features include susceptibility to pheochromocytoma and
paraganglioma, and
Cowden-like Syndrome (CWD2).
[0479] Paragangliomas-5 (PGL5) can be caused by heterozygous mutations in the
SDHA gene. Clinical features include hypertension and hyperadrenergic
symptoms,
such as dizziness, tachycardia, and sweating. Patients exhibit high
concentrations of
urinary normetanephrine, norepinephrine, and chromoganin A. Perturbations in
SDHA can also lead to cardiomyopathy and mitochondrial respiratory chain
complex
2 deficiency.
[0480] BCL2 is an integral inner mitochondrial membrane protein of relative
molecular mass 25,000. Overexpression of BCL2 blocks the apoptotic death of a
pro-
B-lymphocyte cell line, and can result in B-cell lymphoma. Thus, BCL2 is
unique
among proto-oncogenes, being localized in mitochondria and interfering with
programmed cell death independent of promoting cell division.
[0481] Heterozygous mutations in the fumarate hydratase gene can cause
hereditary
leiomyomatosis and renal cell cancer.
[0482] Susceptibility to the development of neuroblastoma-1 (NBLST1) and
isolated pheochromocytoma is associated with mutations in the KIF1B gene,
which
encodes kinesin family member 1B. This protein is a member of the kinesin
family of
proteins that are essential for intracellular transport, including the
transport of
mitochondria. NBLST1 is common neoplasm of early childhood arising from
embryonic cells that form the primitive neural crest and give rise to the
adrenal
medulla and the sympathetic nervous system. Pheochromocytoma is caused by a
catecholamine-producing tumor of chromaffin tissue of the adrenal medulla or
sympathetic paraganglia. The cardinal symptom, reflecting the increased
secretion of
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epinephrine and norepinephrine, is hypertension, which may be persistent or
intermittent.
Nephronophthisis
[0483] Nephronophthisis (NPHP), also known as nephronophthisis-like
nephropathy 1, is an autosomal recessive cystic kidney disease characterized
by the
onset of end-stage renal failure in the first three decades of life. Features
of NPHP
include irregular tubular basement membrane, tubular cyst formation, and
interstitial
cell infiltration with fibrosis. The disorder is also frequently associated
with
extrarenal manifestations including liver fibrosis, retinal degeneration, and
central
nervous system abnormalities. Mutations in ten causative genes (NPHP1-NPHP9
and
NPHP11), whose products localize to the primary cilia-centrosome complex, have
been identified and are linked to the development of NPHP. In addition,
homozygous
frameshift and splice-site mutations in the X-prolyl aminopeptidase 3
(XPNPEP3)
gene have been identified and are associated with the development of a
nephronophthisis-like nephropathy. In contrast to all known NPHP proteins,
XPNPEP3 localizes to mitochondria of renal cells. XPNPEP3 belongs to a family
of
X-pro-aminopeptidases that utilize a metal cofactor and remove the N-terminal
amino
acid from peptides with a proline residue in the penultimate position.
Neuropathy; Ataxia; Retinitis Pigmentosa (NARP)
[0484] NARP Syndrome is caused by mutations in the gene encoding subunit 6 of
mitochondrial H(+)-ATPase (MTATP6) and usually presents at childhood (2nd
decade) or adult stage. The MT-ATP6 protein forms one subunit of complex V
(ATP
synthase), which is responsible for the last step in ATP production. Mutations
in MT-
ATP6 alter the structure or function of ATP synthase, reducing the ability of
mitochondria to produce ATP. Most individuals with NARP have a specific point
mutation at nucleotide 8993, with a T8993G mutation causing more severe
symptoms
than a T8993C mutation. Some cases involve a G8989C point mutation.
[0485] Clinical features include sensory neuropathy, proximal and distal
weakness,
reduced tendon reflexes, retinitis pigmentosa, reduced night vision, Bull's
eye
maculopathy, pigment in posterior pole & mid-periphery, small retinal scars,
vascular
narrowing, central and paracentral scotomas, gait disorder, dysarthria,
dementia,
seizures, Tonic-clonic seizures, developmental delay, pyramidal signs,
dystonia,
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hearing loss, cardiac hypertrophy, denervation, cerebral atrophy, cortical
cerebellar
atrophy, focal cystic necrosis, and rod or cone dysfunction.
[0486] Disruption of MTATP6 function can result in Distal Hereditary Motor
Neuropathy (dHMN), which usually presents during the 1st or 2nd decade of
life.
Clinical features include gait disorder, weakness, sensory loss, brisk tendon
reflexes,
extensor plantar reflex, pes cavus, Kyphoscoliosis, motor axon loss, sensory
axon
loss, and reduced Complex V activity.
Ornithine Transcarbamylase Deficiency
[0487] Ornithine transcarbamylase (OTC) deficiency is an X-linked inborn error
of
metabolism of the urea cycle that causes hyperammonemia. Ornithine
carbamoyltransferase is a nuclear-encoded mitochondrial matrix enzyme that
catalyzes the second step of the urea cycle in mammals. OTC deficiency is
associated
with mutations in the OTC gene. OTC is the most common urea cycle defect and
is
characterized by the triad of hyperammonemia, encephalopathy, and respiratory
alkalosis.
Paroxysmal Nonkinesigenic Dyskinesia
[0488] Paroxysmal nonkinesigenic dyskinesia (PNKD) is an autosomal dominant
movement disorder characterized by sudden attacks of dystonia, chorea, and
athetosis.
PNKD is associated with mutations in the myofibrillogenesis regulator-1 gene
(MR1).
MR1 is transcribed into three alternatively spliced isoforms: long (MR-1L);
medium
(MR-1M); and small (MR-1S). The MR-1L and MR-1M isoforms are mitochondrial
proteins imported into the organelle by a 39-amino acid, N-terminal
mitochondrial
targeting sequence (MTS).
Progressive External Ophthalmoplegia (PEO)
[0489] PEO is a slowly progressive disorder associated with slow eye movement
speed, limited gaze in all directions, ptosis, and extraocular muscle
pathology. PEO
may arise sporadically or as a consequence of autosomal dominant, autosomal
recessive, or maternal inheritance.
1. Sporadic PEO
[0490] Syndromes with severe ophthalmoplegia include Kearns-Sayre, PEO +
Proximal myopathy, and PEO.
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[0491] Chronic PEO is caused by a single large mtDNA deletion and usually
manifests at > 20 years of age. Symptoms include ophthalmoplegia, and heart
block
in some patients.
[0492] PEO with sensory ataxic neuropathy usually manifests between 10 to 31
years of age. Clinical features include sensory loss, gait disorder, distal
motor
weakness, absent tendon reflexes, external ophthalmoplegia, ptosis,
dysarthria, facial
weakness, myopathy, and ragged red muscle fibers.
[0493] Mutations in MTTQ can result in PEO that presents at 5 years of age.
Clinical symptoms include weakness, ptosis, dysphonia, dysphagia,
ophthalmoplegia,
reduced tendon reflexes, ragged red fibers, COX negative muscle fibers and
impairment in mitochondrial protein synthesis.
[0494] Mutations in MTTA can result in PEO that presents in the 6th decade of
life.
Clinical symptoms include ptosis, weakness, decreased eye movements,
dysphagia,
COX negative muscle fibers, mitochondria' proliferation, and partial defect of
Complex I.
[0495] Mutations in MTTL can result in PEO that presents in the 5th decade of
life.
Clinical symptoms include ptosis, migraines, decreased eye movements, exercise
intolerance, short stature, COX negative, ragged red muscle fibers, and
partial defects
of Complex I & IV.
[0496] Mutations in MTTY can result in PEO that presents in the 4th decade of
life.
Clinical symptoms include ptosis, exercise intolerance, ophthalmoplegia,
myopathy,
COX negative muscle fibers with increased SDH staining, and partial defect of
Complex I & IV. Other MTTY syndromes include exercise intolerance
with Complex III deficiency, and focal segmental glomerulosclerosis and
dilated
cardiomyopathy.
2. Maternally-inherited PEO
[0497] Maternal PEO is caused by mtDNA point mutations in MTTL, MTTN,
MTTQ, MTTA, and MTTK.
3. Autosomal Dominant PEO
[0498] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-3 (PEOA3) is caused by heterozygous
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mutations in the nuclear-encoded twinkle gene (ClOORF2), which binds to the 9-
subunit of polymerase-y (POLG). Progressive external ophthalmoplegia is
characterized by multiple mitochondrial DNA deletions in skeletal muscle. The
most
common clinical features include adult onset of weakness of the external eye
muscles
and exercise intolerance. Patients with C100RF2-linked adPEO may have other
clinical features including proximal muscle weakness, muscle pain, cramps,
respiratory failure, ataxia, peripheral neuropathy, cardiomyopathy, cataracts,
depression, ptosis, dysarthria, dysphagia, dysphonia, hearing loss, memory
loss,
Parkinsonism, avoidant personality traits, SDH+ COX negative muscle fibers,
ragged
red fibers, ketoacidosis, cortical atrophy or white matter lesions, and
endocrine
abnormalities. Variant syndromes involving Twinkle mutations include Infantile
Onset Spinocerebellar Ataxia (IOSCA), SANDO, MTDPS7, PEO + Dementia, PEO +
Parkinson, and Perrault.
[0499] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-2 (PEOA2) is caused by heterozygous
mutations in the nuclear-encoded ANTI gene (SLC25A4), which usually manifests
at
20 to 35 years of age. Clinical symptoms include ophthalmoplegia, ptosis,
dysphagia,
dysphonia, face, proximal, and respiratory weakness, cataracts, sensorineural
hypoacusia, goiter, dementia, Bipolar affective disorder, high serum lactic
acid, and
multiple mtDNA deletions. Over-expression of ANTI is also observed in FSH
dystrophy muscle.
[0500] PEOA2 can also be caused by heterozygous mutations in the nuclear-
encoded twinkle gene (C100RF2). The most common mutation is an Ala359Thr
missense mutation, the homozygous version producing more severe effects than
the
heterozygous version. In addition, adPEO is characterized by multiple
mitochondrial
DNA deletions in skeletal muscle. A severe CNS phenotype with polyneuropathy
is
associated with a 39-bp deletion. In general, the mutations tend to cluster in
regions
of the protein involved in subunit interactions (amino acids 303-508). The
twinkle
protein is involved in mtDNA metabolism and could function as an adenine
nucleotide-dependent DNA helicase. The function of the twinkle protein is
believed
to be critical for lifetime maintenance of mtDNA integrity. The most common
clinical features of adPEO include adult onset of weakness of the external eye
muscles and exercise intolerance. Patients with C100RF2-linked adPEO may have
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other clinical features including proximal muscle weakness, ataxia, peripheral
neuropathy, cardiomyopathy, cataracts, depression, and endocrine
abnormalities.
[0501] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-1 (PEOA1) is caused by mutations in the
nuclear-encoded DNA polymerase-gamma gene (POLG). Autosomal recessive PEO
(PEOB) is also caused by mutations in the POLG gene. PEO1 manifests at 16 to
39
years of age. Clinical features include PEO, muscle weakness, exercise
intolerance,
sensory loss, absent tendon reflexes, poorly formed 2 sexual characteristics,
early
menopause, testicular atrophy, Parkinsonism, proximal weakness & wasting,
dysphagia, dysphonia, facial diplegia, abnormal gait, depression,
extrapyramidal
syndrome, ragged red fibers, COX negative and SDH + fibers, and proximal
myopathy. Other clinical syndromes associated with dominant POLG mutations
include PEO+ Demyelinating neuropathy, PEO + Distal myopathy, Sensory
neuropathy, PEO & Tremor, and PEO + Hypogonadism. Clinical syndromes
associated with recessive POLG mutations include Alpers-Huttenlocher
Syndrome (AHS), Childhood myocerebrohepatopathy spectrum (MCHS), Myoclonic
epilepsy, Myopathy, Sensory ataxia (MEMSA), SANDO, MIRAS, MNGIE and
Parkinsons.
105021 PEO+ Demyelinating neuropathy manifests at the second decade of life
and
is characterized by weakness, sensory loss, absent tendon reflexes, PEO with
ptosis,
dysphonia, dysphagia, nerve pathology, ragged red fibers, COX negative fibers,
and
reduced Complex I, III & IV activity.
[0503] Mitochondrial Recessive Ataxia Syndrome (MIRAS) usually manifests
between the ages of 5 to 38 years. Clinical symptoms include balance disorder,
epilepsy, dysarthria, nystagmus, reduced tendon reflexes, pain, sensory
neuropathy,
cramps, cognitive impairment, athetosis, tremor, obesity, and eye movement
disorders.
[0504] PEO + Hypogonadism is characterized by delayed sexual maturation,
primary amenorrhea, early menopause, testicular atrophy, cataracts, cerebellar
ataxia,
tremor, Parkinsonism, depression, mental retardation, polyneuropathy, PEO,
dysarthria, dysphonia, proximal weakness, rhabdomyolysis, hypoacusis, Pes
cavus,
ragged red fibers, and cytochrome c oxidase negative muscle fibers.
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[0505] Distal myopathy, Cachexia & PEO is caused by dominant or sporadic
mutations in POLG1 and usually manifests between the third and fourth decade
of
life. Clinical features include weakness, dysarthria, dysphagia, cachexia,
ptosis,
ophthalmoplegia, cataracts, and ragged red & COX negative muscle fibers.
[0506] Autosomal dominant progressive external ophthalmoplegia (adPEO) with
mitochondrial DNA (mtDNA) deletions-4 (PEOA4) is caused by heterozygous
mutations in the nuclear-encoded DNA polymerase gamma-2 gene (POLG2).
Progressive external ophthalmoplegia-4 is an autosomal dominant form of
mitochondrial disease that variably affects skeletal muscle, the nervous
system, the
liver, and the gastrointestinal tract. Age of onset ranges from infancy to
adulthood.
The phenotype ranges from relatively mild, with adult-onset skeletal muscle
weakness
and weakness of the external eye muscles, to severe, with a multisystem
disorder
characterized by delayed psychomotor development, lactic acidosis,
constipation, and
liver involvement. Clinical features include ptosis, external ophthalmoplegia,
exercise intolerance, pain, weakness, seizures, hypotonia, impaired glucose
tolerance,
high lactate, cerebellar atrophy, cardiac conduction defect, and abnormal
mitochondrial morphology.
[0507] Autosomal dominant progressive external ophthalmoplegia-6 (PEOA6) is
caused by heterozygous mutations in the DNA2 gene. PEOA6 is characterized by
muscle weakness, mainly affecting the lower limbs, external ophthalmoplegia,
exercise intolerance, and mitochondrial DNA (mtDNA) deletions on muscle
biopsy.
Clinical features include hypotonia, myalgia, exertional dyspnea, ptosis or
ophthalmoplegia, lordosis, and muscular atrophy. Symptoms may appear in
childhood or adulthood and show slow progression.
[0508] In some embodiments, dominant POLG mutations may lead to sensory
neuropathy, tremor and PEO.
4. Autosomal Recessive PEO
[0509] PEO + Myopathy & Parkinsonism is an adult onset autosomal recessive
disorder. Clinical features include extrapyramidal signs (e.g., akinesia,
rigidity, rest
tremor), ptosis, ophthalmoplegia, proximal & facial weakness, occasional
distal leg
weakness, hearing loss, SDH + and COX negative muscle fibers, reduced complex
III
activity, and multiple mtDNA deletions.
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[0510] Autosomal recessive progressive external ophthalmoplegia (PEOB) is
caused by homozygous or compound heterozygous mutations in the nuclear-encoded
DNA polymerase-gamma gene (POLG). Recessive mutations in the POLG gene can
also cause sensory ataxic neuropathy, dysarthria, and ophthalmoparesis
(SANDO),
which shows overlapping features. Autosomal recessive PEO is usually more
severe
than autosomal dominant PEO.
[0511] SANDO usually manifests between the ages of 16 to 38 years and is
characterized by exercise intolerance, ptosis, and paresthesias. Clinical
symptoms
include sensory loss, ataxic gait, pseudoathetosis, small fiber modality loss,
weakness,
reduced tendon reflexes, ptosis, ophthalmoplegia, dysarthria, myoclonic
epilepsy,
depression, high CSF and serum lactate, degeneration of spinocerebellar and
dorsal
column tracts, thalamic lesions, cerebellar atrophy or White matter lesions,
ragged red
fibers, loss of myelinated & unmyelinated axons, and reduced activity of
Complex I
& IV.
[0512] Mitochondrial DNA Depletion Syndrome-11 (MTDPS11) can be caused by
homozygous mutations in the MGME1 gene. Mitochondria' DNA Depletion
Syndrome-11 is an autosomal recessive mitochondria' disorder characterized by
onset
in childhood or adulthood of progressive external ophthalmoplegia (PEO),
ptosis,
muscle weakness and atrophy, exercise intolerance, dysphonia, dysphagia, and
respiratory insufficiency due to muscle weakness. More variable features
include
spinal deformity, emaciation, and cardiac abnormalities. Skeletal muscle
biopsies
show deletion and depletion of mitochondrial DNA (mtDNA) with variable defects
in
respiratory chain enzyme activities. Additional features include scapular
winging,
mental retardation, memory deficits, nausea, flatulence, abdominal fullness,
diarrhea,
loss of appetite, SDH+ & COX negative fibers, Complex I or I + IV
deficiencies, and
cerebellar atrophy.
[0513] PEO with cardiomyopathy is caused by recessive mutations in POLG and
usually manifests at childhood. Clinical features include PEO, cardiomyopathy,
proximal weakness, multiple mtDNA deletions, and ragged red fibers.
[0514] An additional POLG syndrome is Parkinsonism without external
ophthalmoplegia. Clinical feature include Parkinsonism or Dystonia, weakness,
high
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serum lactate, COX negative muscle fibers, polyneuropathy, and cerebral and
cerebellar atrophy.
[0515] Ataxia with sensory neuropathy is a variant POLG syndrome that is not
associated with ophthalmoplegia.
PEPCK Deficiency
[0516] PEPCK deficiency is an autosomal recessive disorder of carbohydrate
metabolism. A deficiency of the enzyme phosphoenolpyruvate carboxykinase
(PEPCK), which is a key enzyme in gluconeogenesis, causes acidemia. PEPCK
converts oxaloacetate into phosphoenolpyruvate and carbon dioxide. PEPCK
deficiency is characterized by hypoglycemia, hypotonia, hepatomegaly, liver
impairment, and failure to thrive. In humans, there are two forms of PEPCK
deficiency: cytosolic and mitochondrial. Both forms result from an inherited
deficiency in the enzyme PEPCK. Cytosolic PEPCK is encoded by PCK1 and the
mitochondrial enzyme is encoded by PCK2. PCK2 encodes a deduced 640-amino
acid polypeptide that shares 70% homology with cytosolic PCK.
Perrault Syndromes
[0517] Perrault Syndrome (PRLTS) is a sex-influenced, autosomal recessive
disorder characterized by sensorineural deafness in both males and females and
premature ovarian failure (POF) secondary to ovarian dysgenesis in females.
Some
patients also have neurologic manifestations, including mild mental
retardation and
cerebellar and peripheral nervous system involvement. Perrault Syndrome is
classified into type I, which is static and without neurologic disease, and
type II,
which is with progressive neurologic disease.
[0518] Perrault Syndrome-1 (PRLTS1) is caused by compound heterozygous
mutations in the HSD17B4 gene, which encodes a D-bifunctional protein (DBP).
[0519] Perrault Syndrome-2 (PRLTS2) is caused by compound heterozygous
mutations in the mitochondrial histidyl-tRNA synthetase, HARS2. Affected
females
have primary amenorrhea, streak gonads, and infertility, whereas affected
males show
normal pubertal development and are fertile
[0520] Perrault Syndrome-3 (PRLTS3) is caused by homozygous or compound
heterozygous mutations in the CLPP gene, an endopeptidase component of a
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mitochondrial ATP-dependent proteolytic complex required for protein
degradation in
the mitochondria.
[0521] Perrault Syndrome-4 (PRLTS4) is caused by homozygous or compound
heterozygous mutations in the LARS2 gene.
[0522] Mutations in the Twinkle gene can also lead to Perrault Syndrome. In
addition to sensorineural deafness and female hypogonadism, patients exhibit
symptoms such as nystagmus, gait disorder, epilepsy, polyneuropathy,
ophthalmoplegia, increased serum lactate, and muscle atrophy.
Propionic Acidemia
[0523] Propionic acidemia (PA) is caused by a deficiency of propionyl-CoA
carboxylase (PCC), a biotin-dependent carboxylase located in the mitochondrial
inner
membrane space. PCC catalyzes the conversion of propionyl-CoA to methylmalonyl-
CoA, which eventually enters the TCA cycle as succinyl-CoA. Propionyl-CoA is
common to the pathway for degradation of some amino acids (isoleucine, valine,
threonine, and methionine), odd-chain fatty acids, and cholesterol. Gut
bacteria (i.e.,
Propionibacterium sp.) are also an important source of propionate metabolized
through PCC. PCC is a heterododecamer (a606) composed of six a-subunits
encoded
by PCCA and six 0-subunits encoded by PCCB. Biallelic mutation of either PCCA
or
PCCB results in PA.
[0524] Patients with PA exhibit episodic vomiting, lethargy, ketosis,
neutropenia,
periodic thrombocytopenia, hypogammaglobulinemia, developmental retardation,
and
intolerance to protein. Chemical features include hyperglycinemia and
hyperglycinuria.
Pyruvate Disorders
[0525] Pyruvate dehydrogenase complex (PDHC) is a nuclear-encoded
mitochondrial matrix multienzyme complex composed of multiple copies of 3
enzymes: El, Dihydrolipoyl transacetylase (DLAT), and Dihydrolipoyl
dehydrogenase (DLD). PDHC catalyzes the irreversible conversion of pyruvate
into
acetyl-CoA. Pyruvate disorders may arise as a consequence of perturbations in
PDHAl, PDHB, PDHX, PDK3, PDP1, DLAT, DLD, NFUl, BOLA3, Lipoic acid
synthase (LIAS), TPK1, Pyruvate carboxylase and Pyruvate transporter.
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1. Pyruvate Carboxylase Deficiency
[0526] Pyruvate carboxylase converts pyruvate & CO2 to oxaloacetate and plays
a
role in gluconeogenesis. Pyruvate carboxylase deficiency is caused by
mutations in
the pyruvate carboxylase gene and is categorized into 3 phenotypic subgroups:
Type
A, Type B and Type C. Type A patients have lactic acidemia and psychomotor
retardation, whereas Type B patients have a more complex biochemical phenotype
with increased serum lactate, ammonia, citrulline, and lysine, as well as an
intracellular redox disturbance in which the cytosolic compartment is more
reduced
and the mitochondrial compartment is more oxidized. Type B patients have
decreased survival compared to group A, and usually do not survive beyond 3
months
of age. Type C is relatively benign. Clinical features include hypotonia,
delayed
neurologic development, ataxia, chronic lactic acidemia, developmental delay,
seizures, lactic acidosis, increased lactate:pyruvate & acetoacetate:3-
hydroxybutyrate
ratios, and episodic metabolic acidosis.
2. Pyruvate Dehydrogenase El -c Deficiency (PDHAD)
[0527] Pyruvate dehydrogenase El-alpha deficiency (PDHAD) is caused by
mutations in the gene encoding the El-alpha polypeptide (PDHA1) of the
pyruvate
dehydrogenase (PDH) complex. Genetic defects in the pyruvate dehydrogenase
complex are one of the most common causes of primary lactic acidosis in
children.
Most cases are caused by mutation in the El-alpha subunit gene on the X
chromosome. X-linked PDH deficiency is one of the few X-linked diseases in
which
a high proportion of heterozygous females manifest severe symptoms. Clinical
features of PDHAD include seizures, hyperventilation, episodic cerebellar
ataxia,
chorioathetosis, lactic acidosis, carbohydrate intolerance, high serum pyruvic
acid,
and high serum alanine.
[0528] Variant syndromes associated with Pyruvate dehydrogenase El -alpha
deficiency are also common and are characterized by hypotonia, lethargy,
seizures,
dystonia, psychomotor retardation, Leigh-like lesions and hyperlactataemia.
3. Pyruvate Dehydrogenase E1-3 Deficiency (PDHBD)
[0529] Pyruvate dehydrogenase El-beta deficiency (PDHBD) is caused by
homozygous mutations in the PDHB gene, and typically presents at the infant
stage.
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Clinical symptoms include hypotonia, respiratory insufficiency, lactic
acidosis, corpus
callosum agenesis, and reduced PDH activity.
4. Dihydrolipoamide Dehydrogenase (DLD) Deficiency
[0530] The DLD gene encodes dihydrolipoamide dehydrogenase (EC 1.8.1.4), a
flavoprotein component known as E3 that is common to the 3 alpha-ketoacid
dehydrogenase multienzyme complexes, namely, pyruvate dehydrogenase complex,
the alpha-ketoglutarate dehydrogenase complex (KGDC), and the branched-chain
alpha-keto acid dehydrogenase complex (BCKDC). The enzyme is a functional
homodimer of the DLD protein and catalyzes the oxidative regeneration of a
lipoic
acid cofactor covalently bound to E2 (DBT) yielding NADH. The DLD enzyme is
also a component, referred to as the L protein, of the mitochondrial glycine
cleavage
system (GCS). Clinical symptoms include vomiting and abdominal pain, stroke-
like
episodes, hypothermia, motor retardation, myoglobinuria, exertional fatigue,
lactic
acidosis, hypoglycemia, and high pyruvate, lactate, a-ketoglutarate, and
branched-
chain amino acids.
5. Pyruvate Dehydrogenase Phosphatase Deficiency (PDHPD)
[0531] Pyruvate dehydrogenase phosphatase deficiency can be caused by
mutations
in the PDP1 gene. Clinical features include hypotonia, developmental delay,
seizures,
lactic acidosis, and posterior white matter pathology.
6. Pyruvate Dehydrogenase E3-binding Protein Deficiency (PDHXD)
[0532] Pyruvate dehydrogenase E3-binding protein deficiency is caused by
homozygous or compound heterozygous mutations in the PDHX gene. Clinical
features include hypotonia, psychomotor retardation, Leigh Syndrome, optic
atrophy,
diplegia, dysarthria, lactic acidosis, putaminal lesions, and hemolytic
anemia.
7. Mitochondrial Pyruvate Carrier Deficiency (MPYCD)
[0533] Mitochondrial pyruvate carrier deficiency (MPYCD) is an autosomal
recessive metabolic disorder characterized by delayed psychomotor development
and
lactic acidosis with a normal lactate/pyruvate ratio resulting from impaired
mitochondrial pyruvate oxidation. MPYCD is caused by homozygous mutations in
the BRP44L gene and usually manifests at birth or childhood. Clinical features
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include hypotonia, psychomotor retardation, peripheral neuropathy, dysmorphic
features (face, single palmar fold, wide spaced nipples), hepatomegaly,
metabolic
acidosis, hyperlactacidemia, and periventricular cysts.
Schwartz-Jampel Syndrome Type 1 (SJS1)
[0534] Schwartz-Jampel Syndrome type 1 (SJS1) is caused by mutations in the
gene
encoding perlecan (HSPG2), a heparan sulfate proteoglycan. Perlecan is a major
component of basement membranes & interstitial matrix in cartilage and
functions as
a coreceptor for FGF2.
[0535] Schwartz-Jampel Syndrome type lA occurs during childhood (usually < 3
years). Clinical features include respiratory difficulties, impaired
swallowing,
polyhydramnios, absent stomach bubble, short femurs, skeletal contractures,
muscle
stiffness, reduced tendon reflexes, muscle hypertrophy, malignant
hyperthermia,
mental retardation, bone dysplasia, micrognathia, platyspondyly, cleft
vertebrae,
reduced height, kyphoscoliosis, myopia, cataracts, blepharophimosis, medial
displacement of outer canthi, hirsutism, small testes, microstomia, jaw muscle
rigidity. SJS Type 1B occurs at birth and is associated with more severe bone
dysplasia. Silverman-Handmaker type of dyssegmental dysplasia (DDSH) refers to
an allelic disorder with a more severe phenotype.
Selenium Deficiency
[0536] Selenium deficiency results in reduced glutathione peroxidase activity,
oxidative damage, reduced levels of selenoproteins and increased toxicity of
drugs &
toxins (e.g., nitrofurantoin, paraquat). Clinical features include myopathy,
cardiomyopathy, selenoprotein disorders (congenital muscular dystrophy with
rigid
spine, hyperthyroxinemia), nail and hair loss, gastroenteritis, dermatitis,
malabsorption, muscle pain, high serum creatine kinase, low vitamin E levels,
and
enlarged mitochondria.
Short-chain Acyl-CoA Dehydrogenase deficiency
[0537] Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is an autosomal
recessive metabolic disorder of mitochondrial fatty acid beta-oxidation. The
disorder
is associated with mutations in the ACADS gene encoding short-chain acyl-CoA
dehydrogenase. Two clinical phenotypes of SCAD deficiency have been
identified.
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One form of the disorder is an infantile onset characterized by acute
acidosis,
myopathy, failure to thrive, developmental delay, and seizures. The other form
is
observed in middle-aged patients who exhibit chronic myopathy,
ophthalmoplegia,
ptosis, and scoliosis.
Succinyl CoA:3-oxacid CoA Transferase Deficiency
[0538] Succinyl CoA:3-oxacid CoA transferase (SCOT) deficiency is an inborn
error of ketone body metabolism associated with mutations in the OXCT1 gene.
SCOT is a key mitochondrial enzyme in the metabolism of ketone bodies in
various
organs. Deficiency of SCOT activity inhibits peripheral ketone body
utilization and
causes episodes of severe ketoacidosis. Ketones are molecules produced in the
liver
during the breakdown of fats and are the major vectors of energy transfer from
the
liver to extrahepatic tissues. As the first step of ketone body utilization,
SCOT
catalyzes the reversible transfer of CoA from succinyl-CoA to acetoacetate.
Stuve-Wiedemann Syndrome (STWS)
[0539] Stuve-Wiedemann Syndrome (STWS), also known as neonatal Schwartz-
Jampel Syndrome type 2 (SJS2), is caused by a mutation in the leukemia
inhibitory
factor receptor gene (LIFR).
[0540] Stuve-Wiedemann Syndrome (STWS) is an autosomal recessive disorder
characterized by bowing of the long bones and other skeletal anomalies,
episodic
hyperthermia, and respiratory and feeding distress usually resulting in early
death.
Age of onset is typically at birth. Clinical features include hypotonia,
respiratory &
feeding difficulties, hyperthermic episodes, high mortality in infancy, joint
contractures, bent bone dysplasia, bowing of lower limbs, internal cortical
thickening,
wide metaphyses, camptodactyly, spontaneous fractures, short stature,
malignant
hyperthermia, temperature instability, loss of corneal reflex, smooth tongue,
reduced
tendon reflexes, and reduced Complex I and IV activity.
Thrombocytopenia
[0541] Thrombocytopenia (THC) is characterized by a decrease in platelet
count,
resulting in the potential for increased bleeding and a decreased clotting
ability.
Although inherited forms of this syndrome are relatively rare, a number of
genes
underlying thrombocytopenia have been identified. One form of autosomal
dominant
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nonsyndromic thrombocytopenia is caused by a mutation in the CYCS gene
encoding
cytochrome c. Cytochrome c is located in the mitochondria of all aerobic cells
and is
involved in the electron transport chain that functions in oxidative
phosphorylation.
Mutations in the CYCS gene have been shown to increase the apoptotic activity
of
cytochrome c in individuals with autosomal dominant nonsyndromic
thrombocytopenia.
Very Long-chain Acyl-CoA Dehydrogenase Deficiency
[0542] Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a
disorder of fatty acid oxidation associated with the accumulation of fatty
acids and
decreases in cell energy metabolism due to enzyme defects in the fatty acid
metabolic
pathway. VLCADD is caused by homozygous or compound heterozygous mutations
in the ACADVL gene that encodes very long-chain acyl-CoA dehydrogenase. Very
long-chain acyl-CoA dehydrogenase (VLCAD) is unique among the acyl-CoA
dehydrogenases in its size, structure, and intramitochondrial distribution.
Whereas
other acyl-CoA dehydrogenases are homotetramers of a 43- to 45-kD subunit,
VLCAD has been shown to be a 154-kD homodimer of a 70-kD subunit. VLCAD
has been found to be loosely bound to the mitochondrial inner membrane and
required
detergent for stabilization. By contrast, the other three acyl-CoA
dehydrogenases are
readily extractable without detergent, indicating that they are located in the
mitochondrial matrix.
[0543] VLCAD deficiency is classified into three forms: a severe early-onset
with a
high incidence of cardiomyopathy and high mortality; an intermediate form with
childhood onset, usually with hypoketotic hypoglycemia and a more favorable
outcome; and an adult-onset, myopathic form with isolated skeletal muscle
involvement, rhabdomyolysis, and myoglobinuria after exercise or fasting.
Vitamin D-dependent Rickets Type lA
105441 Vitamin D-dependent rickets type 1A (VDDR1A) is an autosomal recessive
disorder characterized by hypocalcemia, secondary hyperparathyroidism, and
early
onset severe rickets. The disorder is caused by a mutation in the CYP27B1 gene
encoding the enzyme 25-hydroxyvitamin D3-1-alpha-hydroxylase, which is
localized
to the mitochondrial inner membrane. 25-hydroxyvitamin D3-1-alpha-hydroxylase
is
expressed in the renal proximal tubule where it catalyzes the hydroxylation of
25-
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hydroxyvitamin D3 into 1-alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3, or
calcitrol).
The active metabolite 1,25(OH)2D3 binds and activates the nuclear vitamin D
receptor (VDR) and regulates physiologic events such as calcium homeostasis
and
cellular differentiation and proliferation.
Wilson's Disease
[0545] Wilson's disease is caused by homozygous or compound heterozygous
mutations in the ATP7B gene. Wilson's disease is an autosomal recessive
disorder
characterized by dramatic build-up of intracellular hepatic copper with
subsequent
hepatic and neurologic abnormalities. In Wilson disease, the basal ganglia and
liver
undergo changes that express themselves in neurologic manifestations and signs
of
cirrhosis, respectively. Markedly reduced levels of cytochrome oxidase
activity and
low ceruloplasmin serum levels are observed in affected individuals.
Ceruloplasmin
functions in enzymatic transfer of copper to copper-containing enzymes such as
cytochrome oxidase.
[0546] There are at least 3 forms of Wilson disease. In a rare 'atypical
form,' the
heterozygotes show about 50% of the normal level of ceruloplasmin. In the 2
typical
forms, the Slavic and the juvenile type, heterozygotes have normal
ceruloplasmin
levels, although they can be identified by decreased reappearance of
radioactive
copper into serum and ceruloplasmin. The Slavic type has a late age of onset
and is
predominantly a neurologic disease. The juvenile type, which occurs in Western
Europeans and several other ethnic groups, has onset before age 16 years and
is
frequently a hepatic disease.
[0547] The Kayser-Fleischer ring is a deep copper-colored ring at the
periphery of
the cornea which is frequently found in Wilson disease and is thought to
represent
copper deposits. Additional clinical symptoms include azure lunulae of the
fingernails, hypercalciuria, nephrocalcinosis, renal stones, nephrolithiasis,
chondrocalcinosis, osteoarthritis, hemolytic anemia, leukoencephalopathy,
neuropathy, respiratory chain defects, myocardial abnormalities, intermittent
paresthesia and weakness in both hands and feet.
Peroxisome Biogenesis Disorder 3A (PBD3A): Zellweger Syndrome
[0548] Zellweger Syndrome (PBD3A) is caused by homozygous or compound
heterozygous mutations in the PEX12 gene on chromosome 17. The peroxisomal
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biogenesis disorder (PBD) Zellweger Syndrome (ZS) is an autosomal recessive
multiple congenital anomaly syndrome resulting from disordered peroxisome
biogenesis. Affected children present in the newborn period with profound
hypotonia, seizures, and inability to feed. Characteristic craniofacial
anomalies, eye
abnormalities, neuronal migration defects, hepatomegaly, and chondrodysplasia
punctata are present. Children with this condition do not show any significant
development and usually die in the first year of life. Brain MRIs of affected
subjects
show reduced white matter and hypoplasia in corpus callosum.
[0549] Another form of peroxisome biogenesis disorder (PBD8B) is caused by
homozygous mutations in the PEX16 gene. Mutations in PEX16 also cause
Zellweger Syndrome. The age of onset usually occurs between 1 to 2 years.
Clinical
symptoms are progressive and include spasticity, dysarthria, dysphagia,
ataxia,
abnormal gait, delayed walking, optic atrophy, cataracts, constipation, and
neuropathy.
[0550] The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and
infantile Refsum disease (IRD) represent the milder manifestations of the
Zellweger
Syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical
course of
patients with the NALD and IRD presentation is variable and may include
developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss,
retinal
dystrophy, and visual impairment. Children with the NALD presentation may
reach
their teens, and those with the IRD presentation may reach adulthood.
Mitochondrial Disorders Associated with Drugs and Toxins
1. Arsenic Trioxide Myopathy
[0551] Arsenic trioxide (ATO) has a proven therapeutic efficacy in acute
promyelocytic leukemia (APL). However, APL patient who have undergone ATO
treatment may develop a delayed, severe, and partially reversible
mitochondrial
myopathy. Affected individuals may present with the inability to walk,
myopathy
with cytoplasmic lipid droplets, decreased mitochondrial respiratory chain
complex
activity, multiple mtDNA deletions, and elevated muscle arsenic content.
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2. Myopathy and Neuropathy Resulting from Nucleoside Analogues
[0552] Nucleoside analogues are molecules that function as nucleosides in DNA
or
RNA replication. These analogues include a range of antiviral products used in
the
prevention of viral replication. Various nucleoside analogues including
azidothymidine (AZT), clevudine, telbivudine, and fialuridine are associated
with the
development myopathies and neuropathies.
3. Germanium Myopathy
[0553] Germanium can have a toxic effect on skeletal muscle leading to
myopathy
and polyneuropathy. Pathological examinations of skeletal muscle from
individuals
affected by germanium intoxication exhibit vacuolar myopathy with lipid
excess,
increased acid phosphatase activity, decreased cytochrome oxidase activity,
and
mitochondrial abnormalities.
4. Parkinsonism and Mitochondrial Complex I Neurotoxicity due to
Trichloroethylene
[0554] Long-term exposure to trichloroethylene is associated with Parkinsonism
and
mitochondrial Complex I neurotoxicity. Neurotoxic actions of trichloroethylene
include selective Complex 1 impairment in the midbrain with concomitant
striatonigral fiber degeneration and loss of dopamine neurons.
5. Valproate-induced Hepatic Failure
[0555] Valproate is an anticonvulsant that is administered to control certain
types of
seizures in the treatment of epilepsy. There is an increased risk of Valproate-
induced
liver failure in patients with hereditary neurometabolic syndromes caused by
mutations of the mitochondrial DNA polymerase y (POLG) gene.
Other Mitochondrial Syndromes Characterized by Infantile and Childhood Onset
1. Neurodegeneration with Brain Iron Accumulation
[0556] Neurodegeneration with brain iron accumulation-4 (NBIA4) is an
autosomal
recessive neurodegenerative disorder caused by a homozygous or compound
heterozygous mutation in the C190RF12 gene. Neurodegeneration with brain iron
accumulation-1 (NBIA1), also known as Hallervorden-Spatz disease, is caused by
a
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homozygous or compound heterozygous mutation in the pantothenate kinase-2
gene,
PANK2.
2. Primary Coenzyme Q10 Deficiency-3
[0557] Primary coenzyme Q10 deficiency-3 (C0Q10D3) is a fatal
encephalomyopathic form of coenzyme Q10 deficiency with nephrotic syndrome
that
can be caused by compound heterozygous mutation in the PDSS2 gene, which
encodes a subunit of decaprenyl diphosphate synthase, the first enzyme of the
CoQ10
biosynthetic pathway.
3. Combined Mitochondrial Complex Deficiencies
[0558] Combined complex deficiencies include combined complex I, II, IV, V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3), combined oxidative phosphorylation deficiency-4 (COXPD4), combined
oxidative phosphorylation deficiency-5 (COXPD5), combined oxidative
phosphorylation deficiency-6 (COXPD6), combined oxidative phosphorylation
deficiency-7 (COXPD7), combined oxidative phosphorylation deficiency-8
(COXPD8), combined oxidative phosphorylation deficiency-9 (COXPD9), combined
oxidative phosphorylation deficiency-10 (COXPD10), combined oxidative
phosphorylation deficiency-11 (COXPD11), combined oxidative phosphorylation
deficiency-12 (COXPD12), combined oxidative phosphorylation deficiency-13
(COXPD13), combined oxidative phosphorylation deficiency-14 (COXPD14),
combined oxidative phosphorylation deficiency-15 (COXPD15), combined oxidative
phosphorylation deficiency-16 (COXPD16), combined oxidative phosphorylation
deficiency-17 (COXPD17), combined oxidative phosphorylation deficiency-18
(COXPD18), combined oxidative phosphorylation deficiency-19 (COXPD19),
combined oxidative phosphorylation deficiency-20 (COXPD20), combined oxidative
phosphorylation deficiency-21 (COXPD21), mitochondrial DNA depletion myopathy
(MTDPS2), and Multiple Mitochondrial Dysfimetions Syndrome (MMDS).
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4. Complex I Deficiency
[0559] Mitochondrial Complex I (NADH-ubiquinone reductase) deficiency is
associated with several disorders including cardiomyopathy due to mutations in
the
NDUFS2 gene, fatal multisystemic complex I deficiency due to mutations in the
NDUFS4 gene, and lethal infantile mitochondrial disease due to mutations in
the
NDUFS6, C200RF7, NDUFAF3, and/or NDUFB2 genes.
5. Complex II Deficiency
[0560] Mitochondrial Complex II (succinate dehydrogenase-CoQ oxoreductase)
deficiency is associated with disorders including Leigh Syndrome due to
mutations in
the SDHA gene, infantile leukoencephalopathy due to SDHAF1 mutations, iron-
sulfur disorders, paragangliomas and pheochromocytomas due to mutations in the
SDHAF2, SDHB, SDHC, and SDHD genes.
6. Complex III Deficiency
[0561] Mitochondrial Complex III (cytochrome reductase) deficiency is
associated
with disorders including insulin-responsive hyperglycemia and encephalopathy
due to
mutations in the CYC1 gene and hypoglycemia due to mutations in the UQCRB
gene.
7. Complex IV Deficiency
[0562] Complex IV (cytochrome oxidase) deficiency is associated with disorders
including developmental delay and multisystem disorders due to mutations in
CEP89,
hepatic failure due to mutations in SC01, leukodystrophies due to mutations in
COX6B1 and/or APOPT1, and spastic ataxia due to mutations in COX10.
8. Complex V Deficiency
[0563] Complex V (ATP synthase) deficiency is associated with disorders
including
apical hypertrophic cardiomyopathy due to mutations in MT-ATP8, dysmorphic
cerebrooculofacioskeletal features due to mutations in ATPAF2, and mental
retardation, polyneuropathy, and episodic lactic acidosis due to mutations in
TTP5E.
9. Fumarase Deficiency
[0564] Fumarase deficiency, also known as fumaric aciduria, is caused by a
homozygous or compound heterozygous mutation in the fumarate hydratase gene
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(FH). Fumarase deficiency is a severe autosomal recessive metabolic disorder
characterized by early-onset hypotonia, profound psychomotor retardation, and
brain
abnormalities, such as agenesis of the corpus callosum, gyral defects, and
ventriculomegaly. Many patients show neonatal distress, metabolic acidosis,
and/or
encephalopathy.
10. 3-Hydroxy-3-methylglutaryl-CoA Synthase-2 Deficiency
105651 Mitochondrial HMG-CoA synthase-2 deficiency is caused by mutation in
the
gene encoding mitochondrial HMG-CoA synthase-2 (HMGCS2). Mitochondrial
HMG-CoA synthase deficiency is an inherited metabolic disorder caused by a
defect
in the enzyme that regulates the formation of ketone bodies. Patients present
with
hypoketotic hypoglycemia, encephalopathy, and hepatomegaly, usually
precipitated
by an intercurrent infection or prolonged fasting.
11. Hyperuricemia, Pulmonary Hypertension, Renal Failure, and Alkalosis
Syndrome
[05661 Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis
(HUPRA) Syndrome is caused by homozygous mutation in the SARS2 gene, which
encodes mitochondrial seryl-tRNA synthetase. HUPRA Syndrome is a severe
autosomal recessive multisystem disorder characterized by onset in infancy of
progressive renal failure leading to electrolyte imbalances, metabolic
alkalosis,
pulmonary hypertension, hypotonia, and delayed development. Affected
individuals
are born prematurely.
12. Linear Skin Lesions
[0567] Linear skin lesions are associated with syndromic microphthalmia-7
(MCOPS7) and reticulolinear aplasia cutis congenita with microcephaly, facial
dysmorphism, and other congenital anomalies (APLCC).
[0568] Syndromic microphthalmia-7 is caused by mutation in the HCCS gene. The
microphthalmia with linear skin defects syndrome (MLS) is an X-linked dominant
disorder characterized by unilateral or bilateral microphthalmia and linear
skin
defects¨which are limited to the face and neck, consisting of areas of
aplastic skin
that heal with age to form hyperpigmented areas¨in affected females and in
utero
lethality for males. A similar form of congenital linear skin defects, also
limited to
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the face and neck and associated with microcephaly, is APLCC, which can be
caused
by mutation in the COX7B gene.
13. Pontocerebellar Hypoplasia Type 6
[0569] Pontocerebellar hypoplasia (PCH) is a heterogeneous group of disorders
characterized by an abnormally small cerebellum and brainstem and associated
with
severe developmental delay. Pontocerebellar hypoplasia type 6 (PCH6) is caused
by
a homozygous or compound heterozygous mutation in the gene encoding
mitochondrial arginyl-tRNA synthetase (RARS2).
14. Pyruvate Dehydrogenase Complex Disorders
[0570] Pyruvate dehydrogenase complex (PDHC) disorders are a common cause of
lactic acidosis and encephalopathy in children. PDHC disorders are associated
with
mutations in the following genes: PDHAl, PDHB, PDHX, PDP1, DLD, DLAT,
LIAS, and TPK1.
15. Mitochondrial DNA Depletion Syndrome-9
[0571] Mitochondrial DNA Depletion Syndrome-9 (MTDPS9P), also known as
severe neonatal lactic acidosis with mtDNA depletion, is caused by a
homozygous or
compound heterozygous mutation in the alpha subunit of the succinate-CoA
ligase
gene (SUCLG1). MTDPS9P is a severe autosomal recessive disorder characterized
by infantile onset of hypotonia, lactic acidosis, severe psychomotor
retardation,
progressive neurologic deterioration, and excretion of methylmalonic acid.
Some
patients with MTDPS9 die in early infancy.
16. Sudden Infant Death Syndrome
[0572] Sudden infant death Syndrome (SIDS) is associated with mutations
identified in MTTL1, which encodes mitochondrial leucine transfer RNA 1,
MTND2,
which encodes NADH dehydrogenase subunit 1, and HADHB, which encodes the
beta subunit of the mitochondrial trifunctional protein.
[0573] In one aspect, the present disclosure provides a method of treating,
ameliorating or preventing a mitochondrial disease or disorder or signs and
symptoms
thereof, comprising administering a therapeutically effective amount of a
composition
comprising mitochondrial fission inhibitor peptides, or derivatives,
analogues, or
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pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*). In some
embodiments of the method, the mitochondrial disease or disorder is selected
from the
group consisting of Alexander disease, Alpers Syndrome, Alpha-ketoglutarate
dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia with
spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia, GRACILE
Syndrome, Bjornstad Syndrome, Leigh Syndrome, mitochondrial complex III
deficiency nuclear type 1 (MC3DN1), combined oxidative phosphorylation
deficiency
18 (COXPD18), Thiamine-responsive megaloblastic anemia syndrome (TRMA),
Pearson Syndrome, HAM Syndrome, Ataxia, Cataract, and Diabetes Syndrome,
MELAS/MERRF Overlap Syndrome, combined oxidative phosphorylation
deficiency-14 (COXPD14), Infantile cerebellar-retinal degeneration (ICRD),
Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10 deficiency-1
(C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation (LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with
optic
atrophy (SPAX4), progressive external ophthalmoplegia with mitochondrial DNA
deletions autosomal dominant type 5 (PEOA5), mitochondrial complex III
deficiency
nuclear type 2 (MC3DN2), episodic encephalopathy due to thiamine
pyrophosphokinase deficiency/Thiamine Metabolism Dysfunction Syndrome-5
(THMD5), Spinocerebellar ataxia-28 (SCA28), autosomal dominant cerebellar
ataxia,
deafness, and narcolepsy (ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar
ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss
(CAPOS)
Syndrome, spinocerebellar ataxia 7 (SCA7), Barth Syndrome, Biotinidase
deficiency,
gyrate atrophy, Syndromic Dominant Optic Atrophy and Deafness (Syndromic
DOAD), Dominant Optic Atrophy plus (D0Aplus), Leber's hereditary optic
neuropathy (LHON), Wolfram Syndrome-1 (WFS1), Wolfram Syndrome-2 (WFS2),
Age-related macular degeneration (ARMD), Brunner Syndrome, Left ventricular
noncompaction-1 (LVNC1), histiocytoid cardiomyopathy, Familial Myalgia
Syndrome, Parkinsonism, Fatal infantile cardioencephalomyopathy due to
cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
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Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP) deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency, cardiomyopathy + encephalomyopathy, mitochondrial phosphate
carrier
deficiency, infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency (CEMCOX2), 0-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency,
ECHS1) deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated
cardiomyopathy with ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12
(MTDPS12), cardiomyopathy due to mitochondrial tRNA deficiencies,
mitochondrial
complex V (ATP synthase) deficiency nuclear type 1 (MC5DN1), combined
oxidative
phosphorylation deficiency-8 (COXPD8), progressive leukoencephalopathy with
ovarian failure (LKENP), combined oxidative phosphorylation deficiency-10
(COXPD10), combined oxidative phosphorylation deficiency-16 (COXPD16),
combined oxidative phosphorylation deficiency-17 (COXPD17), combined oxidative
phosphorylation deficiency-5 (COXPD5), combined oxidative phosphorylation
deficiency-9 (COXPD9), carnitine acetyltransferase (CRAT) deficiency,
carnitine
palmitoyltransferase I (CPT I) deficiency, myopathic carnitine deficiency,
primary
systemic carnitine deficiency (CDSP), carnitine palmitoyltransferase II (CPT
II)
deficiency, carnitine-acylcarnitine translocase deficiency (CACTD), cartilage-
hair
hypoplasia, cerebrotendinous xanthomatosis (CTX), congenital adrenal
hyperplasia
(CAB), megaconial type congenital muscular dystrophy, cerebral creatine
deficiency
syndrome-3 (CCDS3), maternal nonsyndromic deafness, maternal nonsyndromic
deafness, autosomal dominant deafness-64 (DFNA64), Mohr-Tranebjaerg Syndrome,
Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGS SS, diabetes, Dimethylglycine dehydrogenase
deficiency (DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1
(MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple
Mitochondrial Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy
associated with mitochondrial Complex II deficiency, encephalopathies
associated
with mitochondrial Complex I deficiency, encephalopathies associated with
mitochondrial Complex III deficiency, encephalopathies associated with
mitochondrial Complex IV deficiency, encephalopathies associated with
mitochondrial Complex V deficiency, hyperammonemia due to carbonic anhydrase
VA deficiency (CA5AD), early infantile epileptic encephalopathy-3 (EIEE3), 2,4-
Dienoyl-CoA reductase deficiency (DECRD), infection-induced acute
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encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE), hypomyelinating
leukodystrophy (HLD4), exocrine pancreatic insufficiency, dyserythropoietic
anemia
and calvarial hyperostosis, Glutaric aciduria type 1 (GA-1), glycine
encephalopathy
(GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-hydroxyacyl-CoA
dehydrogenase deficiency, familial hyperinsulinemic hypoglycemia (FHH),
hypercalcemia infantile, hyperornithinemia-hyperammonemia-homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion
Body Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous myopathies with anti-mitochondrial antibodies, necrotizing
myopathy
with pipestem capillaries, myopathy with deficient chondroitin sulfate C in
skeletal
muscle connective tissue, benign acute childhood myositis, idiopathic orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated myositis, Facioscapulohumeral dystrophy (FSH), familial idiopathic
inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus, Addison disease,
Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS), focal myositis,
autoimmune fasciitis, Spanish toxic oil-associated fasciitis, Eosinophilic
fasciitis,
Macrophagic myofasciitis, Graft-vs-host disease fasciitis, Eosinophilia-
myalgia
Syndrome, perimyositis, isovaleric acidemia (IVA), Kearnes-Sayre Syndrome
(KSS),
2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle Muscular Dystrophy
Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-Methylcrotonyl-
CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller Syndrome,
Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular atrophy
syndrome, rigid spine syndrome, severe myopathy with motor regression,
Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia,
MNGIE, MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked
distal spinal muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF,
progressive external ophthalmoplegia with myoclonus, deafness and diabetes
(DD),
multiple symmetric lipomatosis, Myopathy with Episodic high Creatine Kinase
(MIMECK), Epilepsia Partialis Continua, malignant hypertherrnia syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
medication-, drug- or toxin-induced myoglobinuria, mitochondrial disorder-
associated
myoglobinuria, hypokalemic myopathy and rhabdomyolysis, muscle trauma-
associated myoglobinuria, ischemia-induced myoglobinuria, infection-induced
myoglobinuria, immune myopathies associated with myoglobinuria, Myopathy,
lactic
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acidosis, and sideroblastic anemia (MLASA), infantile mitochondrial myopathy
due
to reversible COX deficiency (MMIT), Myopathy, Exercise intolerance,
Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and exercise
intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder, maternally-inherited mitochondrial myopathies, myopathy with lactic
acidosis, myopathy with rhabdomyolysis, Myopathy with cataract and combined
respiratory chain deficiency, myopathy with abnormal mitochondrial
translation,
Fatigue Syndrome, myopathy with extrapyramidal movement disorders (MPXPS),
glutaric aciduria II (MADD), primary CoQ10 deficiency-1 (C0Q10D1), primary
C0Q10 deficiency-2 (C0Q10D2), primary C0Q10 deficiency-3 (C0Q10D3), primary
CoQ10 deficiency-5 (C0Q10D5), secondary CoQ10 deficiency, autosomal dominant
mitochondrial myopathy, myopathy with focal depletion of mitochondria,
mitochondrial DNA breakage syndrome (PEO + Myopathy), lipid type mitochondrial
myopathy, multiple symmetric lipomatosis (MSL), N-acetylglutamate synthase
(NAGS) deficiency, Nephronophthisis (NPHP), ornithine transcarbamylase (OTC)
deficiency, neoplasms, NARP Syndrome, paroxysmal nonkinesigenic dyskinesia
(PNKD), sporadic PEO, maternally-inherited PEO, autosomal dominant progressive
external ophthalmoplegia with mitochondrial DNA deletions-3 (PEOA3), autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
2
(PEOA2), autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO +
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal dominant progressive external ophthalmoplegia-6 (PEOA6), PEO +
Myopathy and Parkinsonism, autosomal recessive progressive external
ophthalmoplegia (PEOB), Mitochondrial DNA Depletion Syndrome-11 (MTDPS11),
PEO with cardiomyopathy, PEPCK deficiency, Perrault Syndromes (PRLTS),
propionic acidemia (PA), pyruvate carboxylase deficiency, pyruvate
dehydrogenase
El-alpha deficiency (PDHAD), pyruvate dehydrogenase El-beta deficiency
(PDHBD), dihydrolipoamide dehydrogenase (DLD) deficiency, pyruvate
dehydrogenase phosphatase deficiency, pyruvate dehydrogenase E3-binding
protein
deficiency (PDHXD), mitochondrial pyruvate carrier deficiency (MPYCD),
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Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-chain acyl-
CoA
dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA transferase (SCOT)
deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC), Very
long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-dependent
rickets type 1A (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues, germanium myopathy, Parkinsonism and mitochondrial Complex I
neurotoxicity due to trichloroethylene, valproate-induced hepatic failure,
neurodegeneration with brain iron accumulation-4 (NBIA4), Complex I
deficiency,
Complex II deficiency, Complex III deficiency, Complex IV deficiency, Complex
V
deficiency, Cytochrome c oxidase (COX) deficiency, combined complex I, II, IV,
V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3), combined oxidative phosphorylation deficiency-4 (COXPD4), combined
oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11), combined oxidative phosphorylation deficiency-12 (COXPD12),
combined oxidative phosphorylation deficiency-13 (COXPD13), combined oxidative
phosphorylation deficiency-15 (COXPD15), combined oxidative phosphorylation
deficiency-16 (COXPD16), combined oxidative phosphorylation deficiency-19
(COXPD19), combined oxidative phosphorylation deficiency-20 (COXPD20),
combined oxidative phosphorylation deficiency-21 (COXPD21), fumarase
deficiency,
HMG-CoA synthase-2 deficiency, hyperuricemia, pulmonary hypertension, renal
failure, and alkalosis (HUPRA) Syndrome, syndromic microphthalmia-7,
pontocerebellar hypoplasia type 6 (PCH6), Mitochondrial DNA Depletion Syndrome-
9 (MTDPS9P), and Sudden infant death Syndrome (SIDS).
[0574] In one aspect, the present disclosure provides a method of treating a
disease
or condition characterized by excessive mitochondrial fission, comprising
administering a therapeutically effective amount of a composition comprising
mitochondrial fission inhibitor peptides, or derivatives, analogues, or
pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*).
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[0575] In some embodiments, mitochondrial fission inhibitor peptides, or
derivatives, analogues, or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*) are useful to regulate mitochondrial fission.
[0576] In some embodiments, mitochondrial fission inhibitor peptides, or
derivatives, analogues, or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*) are useful to prevent or treat Leber's Hereditary Optic Neuropathy.
[0577] In some embodiments, mitochondrial fission inhibitor peptides, or
derivatives, analogues, or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*) are useful to prevent or treat Friedreich's Ataxia.
[0578] In some embodiments, mitochondrial fission inhibitor peptides, or
derivatives, analogues, or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*) are useful to treat one or more signs, symptoms or complications of
Friedreich's Ataxia including mitochondrial iron loading, Complex I and ATP
content
deficiency, and defects in iron-sulfur cluster biosynthesis.
[0579] In some embodiments, mitochondrial fission inhibitor peptides, or
derivatives, analogues, or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*) are useful to reduce tumor growth in a subject in need thereof.
Treatment of a Mitochondrial Disease or Disorder
[0580] In some embodiments, the disclosure provides for both prophylactic and
therapeutic methods of treating a subject having or suspected of having a
mitochondrial disease, condition or disorder. For example, in some
embodiments, the
disclosure provides for both prophylactic and therapeutic methods of treating
a
subject having a disruption in oxidative phosphorylation caused by a gene
mutation
e.g., SURF1, POLG etc.
[0581] In some embodiments, the present technology provides methods for the
treatment, amelioration or prevention of a mitochondrial disease, condition or
disorder
in subjects through administration of therapeutically effective amounts of
mitochondrial fission inhibitor peptides (or derivatives, analogues, or
pharmaceutically acceptable salts thereof) of the present technology (e.g.,
P110 and/or
P110*) as disclosed herein to subjects in need thereof. In some embodiments of
the
method, the mitochondrial disease, condition or disorder is selected from the
group
consisting of Alexander disease, Alpers Syndrome, Alpha-ketoglutarate
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dehydrogenase (AKDGH) deficiency, ALS-FTD, Sideroblastic anemia with
spinocerebellar ataxia, Pyridoxine-refractory sideroblastic anemia, GRACILE
Syndrome, Bjornstad Syndrome, Leigh Syndrome, mitochondrial complex III
deficiency nuclear type 1 (MC3DN1), combined oxidative phosphorylation
deficiency
18 (COXPD18), Thiamine-responsive megaloblastic anemia syndrome (TRMA),
Pearson Syndrome, HAM Syndrome, Ataxia, Cataract, and Diabetes Syndrome,
MELAS/MERRF Overlap Syndrome, combined oxidative phosphorylation
deficiency-14 (COXPD14), Infantile cerebellar-retinal degeneration (ICRD),
Charlevoix-Saguenay spastic ataxia, Primary coenzyme Q10 deficiency-1
(C0Q10D1), ataxia oculomotor apraxia type 1 (A0A1), Autosomal recessive
spinocerebellar ataxia-9/ coenzyme Q10 deficiency-4 (C0Q10D4), Ataxia,
Pyramidal
Syndrome, and Cytochrome Oxidase Deficiency, Friedreich's ataxia, Infantile
onset
spinocerebellar ataxia (IOSCA)/ Mitochondrial DNA Depletion Syndrome-7,
Leukoencephalopathy with brainstem and spinal cord involvement and lactate
elevation (LBSL), Autosomal recessive spastic ataxia-3 (SPAX3), MIRAS, SANDO,
mitochondrial spinocerebellar ataxia and epilepsy (MSCAE), spastic ataxia with
optic
atrophy (SPAX4), progressive external ophthalmoplegia with mitochondrial DNA
deletions autosomal dominant type 5 (PEOA5), mitochondrial complex III
deficiency
nuclear type 2 (MC3DN2), episodic encephalopathy due to thiamine
pyrophosphokinase deficiency/Thiamine Metabolism Dysfunction Syndrome-5
(THMD5), Spinocerebellar ataxia-28 (SCA28), autosomal dominant cerebellar
ataxia,
deafness, and narcolepsy (ADCA-DN), Dominant Optic Atrophy (DOA), cerebellar
ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss
(CAPOS)
Syndrome, spinocerebellar ataxia 7 (SCA7), Barth Syndrome, Biotinidase
deficiency,
gyrate atrophy, Syndromic Dominant Optic Atrophy and Deafness (Syndromic
DOAD), Dominant Optic Atrophy plus (D0Aplus), Leber's hereditary optic
neuropathy (LHON), Wolfram Syndrome-1 (WFS1), Wolfram Syndrome-2 (WFS2),
Age-related macular degeneration (ARMD), Brunner Syndrome, Left ventricular
noncompaction-1 (LVNC1), histiocytoid cardiomyopathy, Familial Myalgia
Syndrome, Parkinsonism, Fatal infantile cardioencephalomyopathy due to
cytochrome c oxidase (COX) deficiency-1 (CEMCOX1), Sengers Syndrome,
Cardiofaciocutaneous Syndrome-1 (CFC1), Mitochondrial trifunctional protein
(MTP) deficiency, infantile encephalocardiomyopathy with cytochrome c oxidase
deficiency, cardiomyopathy + encephalomyopathy, mitochondrial phosphate
carrier
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deficiency, infantile cardioencephalomyopathy due to cytochrome c oxidase
(COX)
deficiency (CEMCOX2), 0-Hydroxyisobutyryl CoA Deacylase (HIBCH) deficiency,
ECHS1) deficiency, Maternal Inheritance Leigh Syndrome (MILS), dilated
cardiomyopathy with ataxia (DCMA), Mitochondrial DNA Depletion Syndrome-12
(MTDPS12), cardiomyopathy due to mitochondrial tRNA deficiencies,
mitochondrial
complex V (ATP synthase) deficiency nuclear type 1 (MC5DN1), combined
oxidative
phosphorylation deficiency-8 (COXPD8), progressive leukoencephalopathy with
ovarian failure (LKENP), combined oxidative phosphorylation deficiency-10
(COXPD10), combined oxidative phosphorylation deficiency-16 (COXPD16),
combined oxidative phosphorylation deficiency-17 (COXPD17), combined oxidative
phosphorylation deficiency-5 (COXPD5), combined oxidative phosphorylation
deficiency-9 (COXPD9), carnitine acetyltransferase (CRAT) deficiency,
carnitine
palmitoyltransferase I (CPT I) deficiency, myopathic carnitine deficiency,
primary
systemic carnitine deficiency (CDSP), carnitine palmitoyltransferase II (CPT
II)
deficiency, carnitine-acylcarnitine translocase deficiency (CACTD), cartilage-
hair
hypoplasia, cerebrotendinous xanthomatosis (CTX), congenital adrenal
hyperplasia
(CAH), megaconial type congenital muscular dystrophy, cerebral creatine
deficiency
syndrome-3 (CCDS3), maternal nonsyndromic deafness, maternal nonsyndromic
deafness, autosomal dominant deafness-64 (DFNA64), Mohr-Tranebjaerg Syndrome,
Jensen Syndrome, MEGDEL, reticular dysgenesis, primary coenzyme Q10
deficiency-6 (C0Q10D6), CAGSSS, diabetes, Dimethylglycine dehydrogenase
deficiency (DMGDHD), Multiple Mitochondrial Dysfunctions Syndrome-1
(MMDS1), Multiple Mitochondrial Dysfunctions Syndrome-2 (MMDS2), Multiple
Mitochondrial Dysfunctions Syndrome-3 (MMDS3), childhood leukoencephalopathy
associated with mitochondrial Complex II deficiency, encephalopathies
associated
with mitochondrial Complex I deficiency, encephalopathies associated with
mitochondrial Complex III deficiency, encephalopathies associated with
mitochondrial Complex IV deficiency, encephalopathies associated with
mitochondrial Complex V deficiency, hyperammonemia due to carbonic anhydrase
VA deficiency (CA5AD), early infantile epileptic encephalopathy-3 (EIEE3), 2,4-
Dienoyl-CoA reductase deficiency (DECRD), infection-induced acute
encephalopathy-3 (IIAE3), ethylmalonic encephalopathy (EE), hypomyelinating
leukodystrophy (HLD4), exocrine pancreatic insufficiency, dyserythropoietic
anemia
and calvarial hyperostosis, Glutaric aciduria type 1 (GA-1), glycine
encephalopathy
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(GCE), hepatic failure, 2-hydroxyglutaric aciduria, 3-hydroxyacyl-CoA
dehydrogenase deficiency, familial hyperinsulinemic hypoglycemia (FHH),
hypercalcemia infantile, hyperornithinemia-hyperammonemia-homocitrullinuria
(HHH) Syndrome, Immunodeficiency with hyper-IgM type 5 (HIGM5), Inclusion
Body Myositis (IBM), polymyositis with mitochondrial pathology, IM-Mito,
granulomatous myopathies with anti-mitochondrial antibodies, necrotizing
myopathy
with pipestem capillaries, myopathy with deficient chondroitin sulfate C in
skeletal
muscle connective tissue, benign acute childhood myositis, idiopathic orbital
myositis, masticator myopathy, hemophagocytic lymphohistiocytosis, infection-
associated myositis, Facioscapulohumeral dystrophy (FSH), familial idiopathic
inflammatory myopathy, Schmidt Syndrome (Diabetes mellitus, Addison disease,
Myxedema), TNF receptor-associated Periodic Syndrome (TRAPS), focal myositis,
autoimmune fasciitis, Spanish toxic oil-associated fasciitis, Eosinophilic
fasciitis,
Macrophagic myofasciitis, Graft-vs-host disease fasciitis, Eosinophilia-
myalgia
Syndrome, perimyositis, isovaleric acidemia (IVA), Kearnes-Sayre Syndrome
(KSS),
2-oxoadipic aciduria, 2-aminoadipic aciduria, Limb-girdle Muscular Dystrophy
Syndromes, leukodystrophy, Maple syrup urine disease (MSUD), 3-Methylcrotonyl-
CoA carboxylase (MCC), Methylmalonic aciduria (MMA), Miller Syndrome,
Mitochondrial DNA Depletion Syndrome-2 (MTDPS2), spinal muscular atrophy
syndrome, rigid spine syndrome, severe myopathy with motor regression,
Mitochondrial DNA Depletion Syndrome-3, MELAS Syndrome, camptocormia,
MNGIE, MNGIM Syndrome, Menkes Disease, Occipital Horn Syndrome, X-linked
distal spinal muscular atrophy-3 (SMAX3), methemoglobinemia, MERRF,
progressive external ophthalmoplegia with myoclonus, deafness and diabetes
(DD),
multiple symmetric lipomatosis, Myopathy with Episodic high Creatine Kinase
(MIMECK), Epilepsia Partialis Continua, malignant hyperthermia syndromes,
glycogen metabolic disorders, fatty acid oxidation and lipid metabolism
disorders,
medication-, drug- or toxin-induced myoglobinuria, mitochondria' disorder-
associated
myoglobinuria, hypokalemic myopathy and rhabdomyolysis, muscle trauma-
associated myoglobinuria, ischemia-induced myoglobinuria, infection-induced
myoglobinuria, immune myopathies associated with myoglobinuria, Myopathy,
lactic
acidosis, and sideroblastic anemia (MLASA), infantile mitochondria' myopathy
due
to reversible COX deficiency (MMIT), Myopathy, Exercise intolerance,
Encephalopathy and Lactic acidemia Syndrome, myoglobinuria and exercise
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intolerance syndrome, exercise intolerance, proximal weakness myoglobinuria
syndrome, encephalopathy and seizures syndrome, septo-optic dysplasia,
exercise
intolerance mild weakness, myopathy exercise intolerance, growth or CNS
disorder, maternally-inherited mitochondrial myopathies, myopathy with lactic
acidosis, myopathy with rhabdomyolysis, Myopathy with cataract and combined
respiratory chain deficiency, myopathy with abnormal mitochondrial
translation,
Fatigue Syndrome, myopathy with extrapyramidal movement disorders (MPXPS),
glutaric aciduria II (MADD), primary CoQ10 deficiency-1 (C0Q10D1), primary
C0Q10 deficiency-2 (C0Q10D2), primary C0Q10 deficiency-3 (C0Q10D3), primary
C0Q10 deficiency-5 (COQ I OD5), secondary CoQ10 deficiency, autosomal dominant
mitochondrial myopathy, myopathy with focal depletion of mitochondria,
mitochondrial DNA breakage syndrome (PEO + Myopathy), lipid type mitochondrial
myopathy, multiple symmetric lipomatosis (MSL), N-acetylglutamate synthase
(NAGS) deficiency, Nephronophthisis (NPHP), ornithine transcarbamylase (OTC)
deficiency, neoplasms, NARP Syndrome, paroxysmal nonkinesigenic dyskinesia
(PNKD), sporadic PEO, maternally-inherited PEO, autosomal dominant progressive
external ophthalmoplegia with mitochondrial DNA deletions-3 (PEOA3), autosomal
dominant progressive external ophthalmoplegia with mitochondrial DNA deletions-
2
(PEOA2), autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-1 (PEOA1), PEO+ demyelinating neuropathy, PEO +
hypogonadism, autosomal dominant progressive external ophthalmoplegia with
mitochondrial DNA deletions-4 (PEOA4), distal myopathy, cachexia & PEO,
autosomal dominant progressive external ophthalmoplegia-6 (PEOA6), PEO +
Myopathy and Parkinsonism, autosomal recessive progressive external
ophthalmoplegia (PEOB), Mitochondrial DNA Depletion Syndrome-11 (MTDPS11),
PEO with cardiomyopathy, PEPCK deficiency, Perrault Syndromes (PRLTS),
propionic acidemia (PA), pyruvate carboxylase deficiency, pyruvate
dehydrogenase
El-alpha deficiency (PDHAD), pyruvate dehydrogenase El-beta deficiency
(PDHBD), dihydrolipoamide dehydrogenase (DLD) deficiency, pyruvate
dehydrogenase phosphatase deficiency, pyruvate dehydrogenase E3-binding
protein
deficiency (PDHXD), mitochondrial pyruvate carrier deficiency (MPYCD),
Schwartz-Jampel Syndrome type 1 (SJS1), selenium deficiency, short-chain acyl-
CoA
dehydrogenase (SCAD) deficiency, succinyl CoA:3-oxacid CoA transferase (SCOT)
deficiency, Stuve-Wiedemann Syndrome (STWS), thrombocytopenia (THC), Very
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CA 02881746 2015-02-13
long-chain acyl-CoA dehydrogenase deficiency (VLCADD), Vitamin D-dependent
rickets type 1A (VDDR1A), Wilson's disease, Zellweger Syndrome (PBD3A),
arsenic trioxide myopathy, myopathy and neuropathy resulting from nucleoside
analogues, germanium myopathy, Parkinsonism and mitochondrial Complex I
neurotoxicity due to trichloroethylene, valproate-induced hepatic failure,
neurodegeneration with brain iron accumulation-4 (NBIA4), Complex I
deficiency,
Complex II deficiency, Complex III deficiency, Complex IV deficiency, Complex
V
deficiency, Cytochrome c oxidase (COX) deficiency, combined complex I, II, IV,
V
deficiency, combined complex I, II, and III deficiency, combined oxidative
phosphorylation deficiency-1 (COXPD1), combined oxidative phosphorylation
deficiency-2 (COXPD2), combined oxidative phosphorylation deficiency-3
(COXPD3), combined oxidative phosphorylation deficiency-4 (COXPD4), combined
oxidative phosphorylation deficiency-6 (COXPD6), combined oxidative
phosphorylation deficiency-7 (COXPD7), combined oxidative phosphorylation
deficiency-9 (COXPD9), combined oxidative phosphorylation deficiency-11
(COXPD11), combined oxidative phosphorylation deficiency-12 (COXPD12),
combined oxidative phosphorylation deficiency-13 (COXPD13), combined oxidative
phosphorylation deficiency-15 (COXPD15), combined oxidative phosphorylation
deficiency-16 (COXPD16), combined oxidative phosphorylation deficiency-19
(COXPD19), combined oxidative phosphorylation deficiency-20 (COXPD20),
combined oxidative phosphorylation deficiency-21 (COXPD21), fumarase
deficiency,
HMG-CoA synthase-2 deficiency, hyperuricemia, pulmonary hypertension, renal
failure, and alkalosis (HUPRA) Syndrome, syndromic microphthalmia-7,
pontocerebellar hypoplasia type 6 (PCH6), Mitochondrial DNA Depletion Syndrome-
9 (MTDPS9P), and Sudden infant death Syndrome (SIDS).
[0582] In some embodiments, the present technology provides methods for the
prevention and/or treatment of mitochondrial disease or disorder in a subject
by
administering an effective amount of mitochondrial fission inhibitor peptides
(or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) to a subject in need thereof to reduce
disruption
in oxidative phosphorylation of the subject.
[0583] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
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technology (e.g., P110 and/or P110*) are useful in decreasing intracellular
ROS
(reactive oxygen species) and increasing survival in cells of a subject in
need thereof,
e.g., a subject suffering from a disease or condition characterized by
mitochondrial
dysfunction.
[0584] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in preventing loss of cell
viability in
subjects suffering from a disease or condition characterized by mitochondrial
dysfunction.
[0585] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in decreasing the percent of
cells
showing increased caspase activity in a subject in need thereof, e.g., a
subject
suffering from a disease or condition characterized by mitochondrial
dysfunction.
[0586] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in reducing the rate of ROS
accumulation in a subject in need thereof, e.g., a subject suffering from a
disease or
condition characterized by mitochondrial dysfunction.
[0587] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in inhibiting lipid
peroxidation in a
subject in need thereof, e.g., a subject suffering from a disease or condition
characterized by mitochondrial dysfunction.
[0588] In some embodiments, mitochondria' fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in preventing mitochondrial
depolarization and ROS accumulation in a subject in need thereof, e.g., a
subject
suffering from a disease or condition characterized by mitochondrial
dysfunction.
[0589] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in preventing apoptosis in a
subject in
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need thereof, e.g., a subject suffering from a disease or condition
characterized by
mitochondrial dysfunction.
[0590] In one aspect, the present technology provides a method of preventing,
treating or ameliorating a medical disease or condition by administering a
therapeutically effective amount of mitochondrial fission inhibitor peptides
(or
derivatives, analogues, or pharmaceutically acceptable salts thereof) (e.g.,
P110
and/or P110*) to a subject in need thereof. In some embodiments the medical
disease
or condition is a mitochondrial disorder. In another aspect, the present
technology
provides a method of modulating one or more energy biomarkers, normalizing one
or
more energy biomarkers, or enhancing one or more energy biomarkers by
administering a therapeutically effective amount of mitochondrial fission
inhibitor
peptides (or derivatives, analogues, or pharmaceutically acceptable salts
thereof) (e.g.,
P110 and/or P110*) to a subject in need thereof.
Use of Mitochondrial Fission Inhibitor Peptides to Treat IPF, Alport Syndrome,
Vitiligo, and Porphyria
[0591] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in methods for treating,
ameliorating,
or reversing idiopathic pulmonary fibrosis (IPF). In certain embodiments of
the
method, IPF is induced by TGF-13 signaling. In other embodiments of the
method,
IPF is induced by exposure to bleomycin. In some embodiments of the methods,
IPF
symptoms or signs include an increase in TGF-31-induced epithelial to
mesenchymal
transition (EMT), myofibroblast activation, collagen production, and severe
progressive fibrosis including fibrotic foci and honeycombing. In some
embodiments,
EMT is characterized by loss of epithelial markers such as E-cadherin,
cytoskeletal
reorganization, and transition to a spindle-shaped morphology with the
acquisition of
mesenchymal markers (a-SMA and collagen I). EMT of alveolar epithelial cells
(AECs) has been widely observed in patients with IPF.
[0592] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in reducing the formation of
fibroblast foci and lung scarring in the subject, as evidenced by a decrease
in collagen
content using sircol assay and fibrosis scoring.
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[0593] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in reducing myofibroblast
activation
and collagen production in the subject, as evidenced by a decrease in a-SMA
and
collagen I expression.
[0594] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in reducing TGF-01-induced EMT
in
the subject, as evidenced by the persistence of E-cadherin expression and/or
decrease
in spindle-shaped morphology. In some embodiments, administration of a
therapeutically effective dose of mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) (e.g.,
P110
and/or P110*) to a subject in need thereof, results in a reduction of TGF-131-
induced
EMT in the subject, as evidenced by a decrease in a-SMA or vimentin
expression. In
some embodiments, administration of a therapeutically effective dose of
mitochondrial fission inhibitor peptides (or derivatives, analogues, or
pharmaceutically acceptable salts thereof) (e.g., P110 and/or P110*) to a
subject in
need thereof, results in a reduction of TGF-01-induced EMT in the subject, as
evidenced by a decrease in cytoskeletal reorganization.
[0595] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in treating or ameliorating
melanocyte degeneration in a subject in need thereof In one particular
embodiment,
mitochondrial fission inhibitor peptides (or derivatives, analogues, or
pharmaceutically acceptable salts thereof) of the present technology (e.g.,
P110 and/or
P110*) are useful in the treatment, amelioration or prevention of vitiligo in
subjects
through administration of therapeutically effective amounts of mitochondrial
fission
inhibitor peptides, or derivatives, analogues, or pharmaceutically acceptable
salts
thereof (e.g., P110 and/or P110*), to subjects in need thereof
[0596] Vitiligo is a pigmentation disorder in which melanocytes, the cells
responsible for skin pigmentation, are destroyed. As a result, white patches
appear on
the skin in different parts of the body. Vitiligo lesions can appear anywhere,
but are
most commonly found on the acral areas, mucous membranes (tissues that line
the
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inside of the mouth and nose), retina and genitals. Other symptoms include
increased
photosensitivity, decreased contact sensitivity response to
dinitrochlorobenzene, and
premature whitening or graying of hair that grows on areas affected by
vitiligo. Non-
segmental vitiligo (NSV) is associated with some form of symmetry in the
location of
the patches of depigmentation. Classes of NSV include generalized vitiligo,
universal
vitiligo, and focal vitiligo. Generalized vitiligo (GV), the most common
category,
affects approximately 0.5% of the world's population, with an average age of
onset at
about 24 years and occurring with approximately equal frequencies in males and
females. Vitiligo lesions have an infiltrate of inflammatory cells,
particularly
cytotoxic and helper T cells and macrophages. Patients with vitiligo are also
more
likely to have at least one other autoimmune disease including Hashimoto's
thyroiditis, Graves' disease, pernicious anemia, rheumatoid arthritis,
psoriasis, type I
diabetes, Addison's disease, celiac disease, inflammatory bowel disorder, and
systemic lupus erythematosus.
[0597] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in the treatment, amelioration
or
prevention of porphyria in a subject in need thereof. The porphyrias, are
metabolic
disorders, each resulting from the deficiency of a specific enzyme in the heme
biosynthetic pathway. These enzyme deficiencies are inherited as autosomal
dominant, autosomal recessive, or X-linked traits, with the exception of the
most
common porphyria, porphyria cutanea tarda, which usually is sporadic.
Porphyrias
have been classified as either hepatic or erythropoietic depending on the
primary site
of overproduction and accumulation of porphyrin precursors or porphyrins,
although
some porphyrias have overlapping features. The hepatic porphyrias are
characterized
by overproduction and initial accumulation of the porphyrin precursors, ALA
and
PBG, and/or porphyrins primarily in the liver, whereas in the erythropoietic
porphyrias, overproduction and initial accumulation of the pathway
intermediates
occur primarily in bone marrow erythroid cells. The eight major porphyrias can
be
classified into three groups: (1) the four acute hepatic porphyrias, (2) the
single
hepatic cutaneous porphyria (i.e., porphyria cutanea tarda), and (3) the three
erythropoietic cutaneous porphyrias. In certain embodiments, the acute hepatic
porphyria is acute intermittent porphyria (AIP), hereditary coproporphyria
(HCP),
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variegate porphyria (VP) or autosomal recessive ALA-dehydratase-deficient
porphyria. In some embodiments, the erythropoietic cutaneous porphyria is
congenital erythropoietic porphyria (CEP), erythropoietic protoporphyria (EPP)
and
X-linked porphyria (XLP). Symptoms associated with porphyria include, but are
not
limited to, cutaneous lesions, blistering skin lesions, hypertrichosis,
hyperpigmentation, thickening and/or scarring of the skin, friability of the
skin,
photosensitivity of the skin, lichenification, leathery pseudovesicles, labial
grooving,
nail changes, life threatening acute neurological attacks, abdominal pain and
cramping, constipation, diarrhea, increased bowel sounds, decreased bowel
sounds,
nausea, vomiting, tachycardia, hypertension, headache, mental symptoms,
extremity
pain, neck pain, chest pain, muscle weakness, sensory loss, tremors, sweating,
dysuria, and bladder distension.
[0598] Variegate porphyria (VP) is an autosomal dominant disorder of porphyrin-
heme metabolism characterized by accumulations of the photosensitizing
porphyrins,
protoporphyrin and coproporphyrin, arising from mutations of the gene encoding
the
enzyme protoporphyrinogen oxidase (PPDX). PPDX is an enzyme in the heme
biosynthetic pathway that catalyzes the oxidation of protoporphyrinogen IX to
form
protoporphyrin IX. PPDX is localized to the mitochondrial intermembrane space
and
is found in various tissues, including liver, lymphocytes, and cultured
fibroblasts.
[0599] Manifestations of VP may include cutaneous manifestations, including
photosensitivity, blistering, skin fragility, and postinflammatory
hyperpigmentation.
Acute exacerbations of VP are characterized by the occurrence of neuro-
visceral
attacks that include abdominal pain, the passage of dark urine, and
neuropsychiatric
symptoms such as bulbar paralysis, quadriplegia, motor neuropathy, and
weakness of
the limbs. VP is associated with a heterozygous mutation in the gene for
protoporphyrinogen oxidase (PPDX). The homozygous variant of VP is
characterized
by severe PPDX deficiency, onset of photosensitization by porphyrins in early
childhood, skeletal abnormalities of the hand, short stature, mental
retardation, and
convulsions.
[0600] In some embodiments, mitochondrial fission inhibitor peptides (or
derivatives, analogues, or pharmaceutically acceptable salts thereof) of the
present
technology (e.g., P110 and/or P110*) are useful in the treatment, amelioration
or
prevention of Alport Syndrome in a subject in need thereof Alport Syndrome is
a
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genetic condition characterized by kidney disease, hearing loss, and eye
abnormalities
and occurs in approximately 1 in 50,000 newborns. Mutations in
the COL4A3, COL4A4, and COL4A5 genes cause Alport Syndrome. These genes
each provide instructions for making one component of a protein called type IV
collagen. This protein plays an important role in the kidneys, specifically in
structures called glomeruli. Glomeruli are clusters of specialized blood
vessels that
remove water and waste products from blood and create urine. Mutations in
these
genes result in abnormalities of the type IV collagen in glomeruli, which
prevents the
kidneys from properly filtering the blood and allows blood and protein to pass
into the
urine. Gradual scarring of the kidneys occurs, eventually leading to
progressive loss
of kidney function and end-stage renal disease in many people with Alport
Syndrome.
[0601] Type IV collagen is also an important component of inner ear
structures,
particularly the organ of Corti, that transform sound waves into nerve
impulses for the
brain. Alterations in type IV collagen often result in abnormal inner ear
function
during late childhood or early adolescence, which can lead to sensorineural
deafness.
In the eye, type IV collagen is important for maintaining the shape of the
lens and the
normal color of the retina. Mutations that disrupt type IV collagen can result
in
misshapen lenses (anterior lenticonus) and an abnormally colored retina.
Significant
hearing loss, eye abnormalities, and progressive kidney disease are more
common in
males with Alport Syndrome than in affected females. Symptoms associated with
Alport Syndrome, including, but not limited to, e.g., hematuria, proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular filtration rate, fibrosis, Glomerular Basement Membrane (GBM)
ultrastructural abnormalities, nephrotic Syndrome, glomerulonephritis, end-
stage
kidney disease, chronic anemia, macrothrombocytopenia, osteodystrophy,
sensorineural deafness, anterior lenticonus, dot-and-fleck retinopathy,
posterior
polymorphous corneal dystrophy, recurrent corneal erosion, temporal macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis.
Therapeutic Methods
106021 The following discussion is presented by way of example only, and is
not
intended to be limiting.
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[0603] One aspect of the present technology includes methods of treating a
mitochondrial disease or disorder in a subject diagnosed as having, suspected
as
having, or at risk of having a mitochondrial disease or disorder. In
therapeutic
applications, compositions or medicaments comprising mitochondrial fission
inhibitor
peptides, or derivatives, analogues, or pharmaceutically acceptable salts
thereof (e.g.,
P110 and/or P110*), are administered to a subject suspected of, or already
suffering
from such a disease (such as, e.g., subjects exhibiting pathological levels of
one or
more energy biomarkers such as, lactic acid (lactate) levels; pyruvic acid
(pyruvate)
levels; total, reduced or oxidized glutathione levels; total, reduced or
oxidized
cysteine levels; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels; oxidized cytochrome C levels; reduced cytochrome C levels;
acetoacetate
levels; beta-hydroxy butyrate levels; 8-hydroxy-2'-deoxyguanosine (8-0HdG)
levels;
and reactive oxygen species levels compared to a normal control subject, or
alternatively a subject diagnosed with a mitochondrial disease or disorder),
in an
amount sufficient to cure, or at least partially arrest, the symptoms of the
disease,
including its complications and intermediate pathological phenotypes in
development
of the disease. In some embodiments of the method, the lactate levels of one
or more
of whole blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid are
abnormal
compared to a normal control subject. In some embodiments of the method, the
pyruvate levels of one or more of whole blood, plasma, cerebrospinal fluid, or
cerebral ventricular fluid are abnormal compared to a normal control subject.
In some
embodiments of the method, the total, reduced or oxidized glutathione levels
of one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular fluid are abnormal compared to a normal control subject. In some
embodiments of the method, the total, reduced or oxidized cysteine levels of
one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular fluid are abnormal compared to a normal control subject.
[0604] Subjects suffering from a mitochondrial disease or disorder can be
identified
by any or a combination of diagnostic or prognostic assays known in the art.
For
example, typical symptoms of a mitochondria' disease or disorder include, but
are not
limited to, poor growth, loss of muscle coordination, muscle weakness,
neurological
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deficit, seizures, autism, autistic spectrum, autistic-like features, learning
disabilities,
heart disease, liver disease, kidney disease, gastrointestinal disorders,
severe
constipation, diabetes, increased risk of infection, thyroid dysfunction,
adrenal
dysfunction, autonomic dysfunction, confusion, disorientation, memory loss,
failure
to thrive, poor coordination, sensory (vision, hearing) problems, reduced
mental
functions, hypotonia, disease of the organ, dementia, respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed
herein.
[0605] In some embodiments, the subject may exhibit pathological levels of one
or
more energy biomarkers such as, lactic acid (lactate) levels; pyruvic acid
(pyruvate)
levels; total, reduced or oxidized glutathione levels; total, reduced or
oxidized
cysteine levels; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels; oxidized cytochrome C levels; reduced cytochrome C levels;
acetoacetate
levels; beta-hydroxy butyrate levels; 8-hydroxy-2'-deoxyguanosine (8-0HdG)
levels;
and reactive oxygen species levels compared to a normal control subject, which
is
measureable using techniques known in the art. In some embodiments of the
method,
the lactate levels of one or more of whole blood, plasma, cerebrospinal fluid,
or
cerebral ventricular fluid are abnormal compared to a normal control subject.
In some
embodiments of the method, the pyruvate levels of one or more of whole blood,
plasma, cerebrospinal fluid, or cerebral ventricular fluid are abnormal
compared to a
normal control subject. In some embodiments of the method, the total, reduced
or
oxidized glutathione levels of one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid are abnormal compared to a
normal
control subject. In some embodiments of the method, the total, reduced or
oxidized
cysteine levels of one or more of whole blood, plasma, lymphocytes,
cerebrospinal
fluid, or cerebral ventricular fluid are abnormal compared to a normal control
subject.
[0606] In some embodiments, the subject may exhibit one or more mtDNA or
nuclear DNA mutations in one or more genes described herein that play a
biological/physiological role in the mitochondria (e.g., mitochondrial protein
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synthesis, respiratory chain function, intergenomic signaling, mitochondrial
importation of nDNA-encoded proteins, synthesis of inner mitochondrial
membrane
phospholipids, mitochondrial motility and fission, mitophagy etc.). Such
mutations
are detectable using techniques known in the art.
[0607] In some embodiments, administration of mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) to subjects suffering from a mitochondrial
disease
or disorder will result in the amelioration or elimination of one or more of
the
following symptoms: poor growth, loss of muscle coordination, muscle weakness,
neurological deficit, seizures, autism, autistic spectrum, autistic-like
features, learning
disabilities, heart disease, liver disease, kidney disease, gastrointestinal
disorders,
severe constipation, diabetes, increased risk of infection, thyroid
dysfunction, adrenal
dysfunction, autonomic dysfunction, confusion, disorientation, memory loss,
failure
to thrive, poor coordination, sensory (vision, hearing) problems, reduced
mental
functions, hypotonia, disease of the organ, dementia, respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed
herein.
[0608] In some embodiments, administration of mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) to subjects suffering from a mitochondrial
disease
or disorder will result in the normalization of one or more energy biomarkers
such as,
lactic acid (lactate) levels; pyruvic acid (pyruvate) levels; total, reduced
or oxidized
glutathione levels; total, reduced or oxidized cysteine levels;
phosphocreatine levels;
NADH (NADH+H30) or NADPH (NADPH+1130 ) levels; NAD or NADP levels;
ATP levels; reduced coenzyme Q (CoQred) levels; oxidized coenzyme Q (CoQox)
levels; total coenzyme Q (CoQtot) levels; oxidized cytochrome C levels;
reduced
cytochrome C levels; acetoacetate levels; beta-hydroxy butyrate levels; 8-
hydroxy-2'-
deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels compared to
untreated subjects with a mitochondrial disease or disorder. In some
embodiments of
the method, the lactate levels of one or more of whole blood, plasma,
cerebrospinal
fluid, or cerebral ventricular fluid in a treated subject are normalized
compared to
untreated subjects with a mitochondrial disease or disorder. In some
embodiments of
the method, the pyruvate levels of one or more of whole blood, plasma,
cerebrospinal
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fluid, or cerebral ventricular fluid in a treated subject are normalized
compared to
untreated subjects with a mitochondrial disease or disorder. In some
embodiments of
the method, the total, reduced or oxidized glutathione levels of one or more
of whole
blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid
in a
treated subject are normalized compared to untreated subjects with a
mitochondrial
disease or disorder. In some embodiments of the method, the total, reduced or
oxidized cysteine levels of one or more of whole blood, plasma, lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid in a treated subject are
normalized
compared to untreated subjects with a mitochondrial disease or disorder.
[0609] One aspect of the present technology includes methods of treating
Alport
Syndrome in a subject diagnosed as having, suspected as having, or at risk of
having
Alport Syndrome. In therapeutic applications, compositions or medicaments
comprising mitochondrial fission inhibitor peptides, or derivatives,
analogues, or
pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*), are
administered
to a subject suspected of, or already suffering from such a disease (such as,
e.g.,
subjects exhibiting aberrant levels and/or function of one or more of ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared to a normal control
subject, or a subject diagnosed with Alport Syndrome), in an amount sufficient
to
cure, or at least partially arrest, the symptoms of the disease, including its
complications and intermediate pathological phenotypes in development of the
disease.
[0610] Subjects suffering from Alport Syndrome can be identified by any or a
combination of diagnostic or prognostic assays known in the art. For example,
typical
symptoms of Alport Syndrome include, but are not limited to, hematuria,
proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular filtration rate, fibrosis, GBM ultrastructural abnormalities,
nephrotic
syndrome, glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia, osteodystrophy, sensorineural deafness, anterior
lenticonus,
dot-and-fleck retinopathy, posterior polymorphous corneal dystrophy, recurrent
corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis.
[0611] In some embodiments, the subject may exhibit aberrant levels or
function of
one or more of ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin
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compared to a normal control subject, which is measureable using techniques
known
in the art. In some embodiments, the subject may exhibit one or more mutations
in
COL4A3, COL4A4, and COL4A5, which are involved in the production or assembly
of type IV collagen fibers and are detectable using techniques known in the
art.
[0612] In some embodiments, Alport Syndrome subjects treated with the
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) will show
amelioration or elimination of one or more of the following symptoms:
hematuria,
proteinuria, cylindruria, leukocyturia, hypertension, edema, microalbuminuria,
declining glomerular filtration rate, fibrosis, GBM ultrastructural
abnormalities,
nephrotic syndrome, glomerulonephritis, end-stage kidney disease, chronic
anemia,
macrothrombocytopenia, osteodystrophy, sensorineural deafness, anterior
lenticonus,
dot-and-fleck retinopathy, posterior polymorphous corneal dystrophy, recurrent
corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis. In certain embodiments, Alport
Syndrome subjects treated with the mitochondrial fission inhibitor peptides
(e.g.,
P110 and/or P110*) will show normalization of one or more of ADAM8,
fibronectin,
myosin 10, MMP-2, MMP-9, and podocin urine levels by at least 10% compared to
untreated Alport Syndrome subjects. In certain embodiments, Alport Syndrome
subjects treated with the mitochondrial fission inhibitor peptides (e.g., P110
and/or
P110*) will show MMP-9 expression levels in mesangial cells that are similar
to that
observed in a normal control subject.
[0613] In another aspect, the present technology includes methods of treating
porphyria in a subject diagnosed as having, suspected as having, or at risk of
having
porphyria. In therapeutic applications, compositions or medicaments comprising
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*), are
administered to
a subject suspected of, or already suffering from such a disease, such as,
e.g., aberrant
levels and/or function of enzymes involved in heme biosynthesis compared to a
normal control subject or porphyria, in an amount sufficient to cure, or at
least
partially arrest, the symptoms of the disease, including its complications and
intermediate pathological phenotypes in development of the disease.
[0614] Subjects suffering from porphyria can be identified by any or a
combination
of diagnostic or prognostic assays known in the art. For example, typical
symptoms
of porphyria include, but are not limited to, cutaneous lesions, blistering
skin lesions,
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hypertrichosis, hyperpigmentation, thickening and/or scarring of the skin,
friability of
the skin, photosensitivity of the skin, lichenification, leathery
pseudovesicles, labial
grooving, nail changes, life threatening acute neurological attacks, abdominal
pain
and cramping, constipation, diarrhea, increased bowel sounds, decreased bowel
sounds, nausea, vomiting, tachycardia, hypertension, headache, mental
symptoms,
extremity pain, neck pain, chest pain, muscle weakness, sensory loss, tremors,
sweating, dysuria, and bladder distension.
[0615] In some embodiments, the subject may exhibit aberrant levels or
function of
enzymes required for heme biosynthesis compared to a normal control subject,
which
is measureable using techniques known in the art. In some embodiments, the
subject
may exhibit one or more mutations in genes encoding enzymes required for heme
biosynthesis, which are detectable using techniques known in the art.
[0616] In some embodiments, administration of mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) to a subject that is diagnosed as having,
is
suspected of having, or is at risk of having porphyria will result in
amelioration or
elimination of one or more of the following symptoms: cutaneous lesions,
blistering
skin lesions, hypertrichosis, hyperpigmentation, thickening and/or scarring of
the
skin, friability of the skin, photosensitivity of the skin, lichenification,
leathery
pseudovesicles, labial grooving, nail changes, life threatening acute
neurological
attacks, abdominal pain and cramping, constipation, diarrhea, increased bowel
sounds,
decreased bowel sounds, nausea, vomiting, tachycardia, hypertension, headache,
mental symptoms, extremity pain, neck pain, chest pain, muscle weakness,
sensory
loss, tremors, sweating, dysuria, and bladder distension. In certain
embodiments of
the method, porphyria subjects treated with the mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) will show normalization of the levels
and/or
function of one or more enzymes required for heme biosynthesis compared to
untreated porphyria subjects.
[0617] One aspect of the present technology includes methods of treating
vitiligo in
a subject diagnosed as having, suspected as having, or at risk of having
vitiligo. In
therapeutic applications, compositions or medicaments comprising mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*), are administered to a
subject
suspected of, or already suffering from such a disease, in an amount
sufficient to cure,
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or at least partially arrest, the symptoms of the disease, including its
complications
and intermediate pathological phenotypes in development of the disease.
[0618] Subjects suffering from vitiligo can be identified by any or a
combination of
diagnostic or prognostic assays known in the art. For example, typical
symptoms of
vitiligo include, but are not limited to, increased photosensitivity,
decreased contact
sensitivity response to dinitrochlorobenzene, depigmentation of the skin,
mucous
membranes (tissues that line the inside of the mouth and nose), retina, or
genitals, and
premature whitening or graying of hair on the scalp, eyelashes, eyebrows or
beard.
[0619] In some embodiments, vitiligo subjects treated with the mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*) will show amelioration or
elimination of
one or more of the following symptoms: increased photosensitivity, decreased
contact
sensitivity response to dinitrochlorobenzene, depigmentation of the skin,
mucous
membranes (tissues that line the inside of the mouth and nose), retina, or
genitals, and
premature whitening or graying of hair on the scalp, eyelashes, eyebrows or
beard.
[0620] In some embodiments, administration of mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) to a subject that is diagnosed as having,
is
suspected of having, or is at risk of having IPF will result in amelioration
or
elimination of one or more of the following symptoms: increase in TGF-01-
induced
epithelial to mesenchymal transition (EMT), myofibroblast activation, collagen
production, lung scarring, and severe progressive fibrosis including fibrotic
foci and
honeycombing.
Prophylactic Methods
[0621] In one aspect, the present technology provides a method for preventing
or
delaying the onset of a mitochondrial disease or disorder in a subject at risk
of having
a mitochondrial disease or disorder. In some embodiments, the subject may
exhibit
one or more mtDNA or nuclear DNA mutations in one or more genes described
herein that play a biological/physiological role in the mitochondria (e.g.,
mitochondrial protein synthesis, respiratory chain function, intergenomic
signaling,
mitochondrial importation of nDNA-encoded proteins, synthesis of inner
mitochondrial membrane phospholipids, mitochondrial motility and fission,
mitophagy etc.).
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[0622] Subjects at risk for pathological levels of one or more energy
biomarkers
such as, lactic acid (lactate) levels (in one or more of whole blood, plasma,
cerebrospinal fluid, or cerebral ventricular fluid); pyruvic acid (pyruvate)
levels (in
one or more of whole blood, plasma, cerebrospinal fluid, or cerebral
ventricular
fluid); total, reduced or oxidized glutathione levels (in one or more of whole
blood,
plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid);
total, reduced
or oxidized cysteine levels (in one or more of whole blood, plasma,
lymphocytes,
cerebrospinal fluid, or cerebral ventricular fluid); phosphocreatine levels;
NADH
(NADH+H30) or NADPH (NADPH+H30 ) levels; NAD or NADP levels; ATP
levels; reduced coenzyme Q (CoQred) levels; oxidized coenzyme Q (CoQox)
levels;
total coenzyme Q (CoQtot) levels; oxidized cytochrome C levels; reduced
cytochrome
C levels; acetoacetate levels; beta-hydroxy butyrate levels; 8-hydroxy-2'-
deoxyguanosine (8-0HdG) levels; and reactive oxygen species levels compared to
a
normal control subject, or alternatively a mitochondrial disease or disorder,
can be
identified by, e.g., any or a combination of diagnostic or prognostic assays
known in
the art.
[0623] In prophylactic applications, pharmaceutical compositions or
medicaments
comprising mitochondrial fission inhibitor peptides, or derivatives,
analogues, or
pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*), are
administered
to a subject susceptible to, or otherwise at risk of a mitochondrial disease
or disorder
in an amount sufficient to eliminate or reduce the risk, or delay the onset of
the
disease, including biochemical, histologic and/or behavioral symptoms of the
disease,
its complications and intermediate pathological phenotypes presenting during
development of the disease. Administration of a prophylactic mitochondrial
fission
inhibitor peptide (e.g., P110 and/or P110*) can occur prior to the
manifestation of
symptoms characteristic of the disease or disorder, such that the disease or
disorder is
prevented or, alternatively, delayed in its progression.
[0624] Subjects at risk for pathological levels of one or more energy
biomarkers
compared to a normal control subject, or alternatively a mitochondrial disease
or
disorder include, but are not limited to, subjects harboring mutations in one
or more
genes described herein that play a biological/physiological role in the
mitochondria
(e.g., mitochondrial protein synthesis, respiratory chain function,
intergenomic
signaling, mitochondrial importation of nDNA-encoded proteins, synthesis of
inner
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mitochondrial membrane phospholipids, mitochondrial motility and fission,
mitophagy etc.).
[0625] In some embodiments, treatment with the mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) will prevent or delay the onset of one or
more of
the following symptoms: poor growth, loss of muscle coordination, muscle
weakness,
neurological deficit, seizures, autism, autistic spectrum, autistic-like
features, learning
disabilities, heart disease, liver disease, kidney disease, gastrointestinal
disorders,
severe constipation, diabetes, increased risk of infection, thyroid
dysfunction, adrenal
dysfunction, autonomic dysfunction, confusion, disorientation, memory loss,
failure
to thrive, poor coordination, sensory (vision, hearing) problems, reduced
mental
functions, hypotonia, disease of the organ, dementia, respiratory problems,
hypoglycemia, apnea, lactic acidosis, seizures, swallowing difficulties,
developmental
delays, movement disorders (dystonia, muscle spasms, tremors, chorea), stroke,
brain
atrophy, or any other sign or symptom of a mitochondrial disease state
disclosed
herein.
[0626] In some embodiments, administration of mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) in subjects with a mitochondrial disease or
disorder will cause the levels of one or more energy biomarkers to be similar
to that
observed in a normal control subject. In certain embodiments, the energy
biomarker
is selected from the group consisting of lactic acid (lactate) levels; pyruvic
acid
(pyruvate) levels; total, reduced or oxidized glutathione levels; total,
reduced or
oxidized cysteine levels; phosphocreatine levels; NADH (NADH+H30) or NADPH
(NADPH+H30 ) levels; NAD or NADP levels; ATP levels; reduced coenzyme Q
(CoQred) levels; oxidized coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot)
levels; oxidized cytochrome C levels; reduced cytochrome C levels;
acetoacetate
levels; beta-hydroxy butyrate levels; 8-hydroxy-2'-deoxyguanosine (8-0HdG)
levels;
and reactive oxygen species levels. In some embodiments of the method, the
lactate
levels of one or more of whole blood, plasma, cerebrospinal fluid, or cerebral
ventricular fluid in a treated subject are similar to that observed in a
normal control
subject. In some embodiments of the method, the pyruvate levels of one or more
of
whole blood, plasma, cerebrospinal fluid, or cerebral ventricular fluid in a
treated
subject are similar to that observed in a normal control subject. In some
embodiments
of the method, the total, reduced or oxidized glutathione levels of one or
more of
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whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular
fluid in
a treated subject are similar to that observed in a normal control subject. In
some
embodiments of the method, the total, reduced or oxidized cysteine levels of
one or
more of whole blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral
ventricular fluid in a treated subject are similar to that observed in a
normal control
subject.
[0627] In one aspect, the present technology provides a method for preventing
or
delaying the onset of Alport Syndrome or symptoms of Alport Syndrome in a
subject
at risk of having Alport Syndrome. In some embodiments, the subject may
exhibit
one or more mutations in COL4A3, COL4A4, and COL4A5, which are involved in
the production or assembly of type IV collagen fibers.
[0628] Subjects at risk for aberrant levels and/or function of one or more of
ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared to a
normal control subject or Alport Syndrome can be identified by, e.g., any or a
combination of diagnostic or prognostic assays known in the art. In
prophylactic
applications, pharmaceutical compositions or medicaments of mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*), are administered to a subject
susceptible
to, or otherwise at risk of a disease or condition such as e.g., Alport
Syndrome, in an
amount sufficient to eliminate or reduce the risk, or delay the onset of the
disease,
including biochemical, histologic and/or behavioral symptoms of the disease,
its
complications and intermediate pathological phenotypes presenting during
development of the disease. Administration of a prophylactic mitochondrial
fission
inhibitor peptide (e.g., P110 and/or P110*) can occur prior to the
manifestation of
symptoms characteristic of the disease or disorder, such that the disease or
disorder is
prevented or, alternatively, delayed in its progression.
[0629] Subjects at risk for aberrant levels and/or function of one or more of
ADAM8, fibronectin, myosin 10, MMP-2, MMP-9, and podocin compared to a
normal control subject or Alport Syndrome include, but are not limited to,
subjects
harboring mutations in COL4A3, COL4A4, and COL4A5, which are involved in the
synthesis of type IV collagen fibers.
[0630] In some embodiments, treatment with the mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) will prevent or delay the onset of one or
more of
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the following symptoms: hematuria, proteinuria, cylindruria, leukocyturia,
hypertension, edema, microalbuminuria, declining glomerular filtration rate,
fibrosis,
GBM ultrastructural abnormalities, nephrotic syndrome, glomerulonephritis, end-
stage kidney disease, chronic anemia, macrothrombocytopenia, osteodystrophy,
sensorineural deafness, anterior lenticonus, dot-and-fleck retinopathy,
posterior
polymorphous corneal dystrophy, recurrent corneal erosion, temporal macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
leiomyomatosis. In certain embodiments, the urine levels of one or more of
ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin in Alport Syndrome subjects
treated with the mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) will
resemble those observed in healthy controls. In certain embodiments, Alport
Syndrome subjects treated with the mitochondrial fission inhibitor peptides
(e.g.,
P110 and/or P110*) will show MMP-9 expression in mesangial cells that is
similar to
that observed in a normal control subject.
[0631] In one aspect, the present technology provides a method for preventing
or
delaying the onset of porphyria or symptoms of porphyria in a subject at risk
of
having porphyria. In some embodiments, the subject may exhibit one or more
mutations in genes encoding enzymes required for heme biosynthesis.
[0632] Subjects at risk for aberrant levels and/or function of enzymes
involved in
heme biosynthesis compared to a normal control subject or porphyria can be
identified by, e.g., any or a combination of diagnostic or prognostic assays
known in
the art. In prophylactic applications, pharmaceutical compositions or
medicaments of
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*), are
administered to
a subject susceptible to, or otherwise at risk of a disease or condition such
as e.g.,
porphyria, in an amount sufficient to eliminate or reduce the risk, or delay
the outset
of the disease, including biochemical, histologic and/or behavioral symptoms
of the
disease, its complications and intermediate pathological phenotypes presenting
during
development of the disease. Administration of a prophylactic mitochondrial
fission
inhibitor peptide (e.g., P110 and/or P110*) can occur prior to the
manifestation of
symptoms characteristic of the disease or disorder, such that the disease or
disorder is
prevented or, alternatively, delayed in its progression.
[0633] Subjects at risk for aberrant levels and/or function of enzymes
involved in
heme biosynthesis compared to a normal control subject, or porphyria include,
but are
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not limited to, subjects harboring mutations in one or more genes encoding
enzymes
involved in heme biosynthesis.
[0634] In some embodiments, treatment with the mitochondrial fission inhibitor
peptides (e.g., P110 and/or P110*) will prevent or delay the onset of one or
more of
the following symptoms: cutaneous lesions, blistering skin lesions,
hypertrichosis,
hyperpigmentation, thickening and/or scarring of the skin, friability of the
skin,
photosensitivity of the skin, lichenification, leathery pseudovesicles, labial
grooving,
nail changes, life threatening acute neurological attacks, abdominal pain and
cramping, constipation, diarrhea, increased bowel sounds, decreased bowel
sounds,
nausea, vomiting, tachycardia, hypertension, headache, mental symptoms,
extremity
pain, neck pain, chest pain, muscle weakness, sensory loss, tremors, sweating,
dysuria, and bladder distension. In certain embodiments of the method,
porphyria
subjects treated with the mitochondrial fission inhibitor peptides (e.g., P110
and/or
P110*) will show normalization of the levels and/or function of one or more
enzymes
required for heme biosynthesis compared to untreated porphyria subjects. In
certain
embodiments, the levels and/or function of one or more enzymes involved in
heme
biosynthesis in porphyria subjects treated with the mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) will resemble those observed in healthy
controls.
[0635] In one aspect, the present technology provides a method for preventing
or
delaying the onset of vitiligo or symptoms of vitiligo in a subject at risk of
having
vitiligo. In some embodiments, the subject may exhibit one or more mutations
in
NLRP1, TYR, HLA class I, HLA class II, HLA class III, PTPN22, XBP1, IL2RA,
LPP, RERE, FOXP1, TSLP, CCR6, GZMB, UBASH3A, C1QTNF6, and FOXP3.
[0636] In prophylactic applications, pharmaceutical compositions or
medicaments
of mitochondrial fission inhibitor peptides, or derivatives, analogues, or
pharmaceutically acceptable salts thereof (e.g., P110 and/or P110*), are
administered
to a subject susceptible to, or otherwise at risk of a disease or condition
such as
vitiligo, in an amount sufficient to eliminate or reduce the risk, or delay
the onset of
the disease, including biochemical, histologic and/or behavioral symptoms of
the
disease, its complications and intermediate pathological phenotypes presenting
during
development of the disease. Administration of a prophylactic mitochondrial
fission
inhibitor peptide (e.g., P110 and/or P110*) can occur prior to the
manifestation of
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symptoms characteristic of the disease or disorder, such that the disease or
disorder is
prevented or, alternatively, delayed in its progression.
[0637] Subjects at risk for vitiligo include, but are not limited to, subjects
harboring
mutations in NLRP1, TYR, HLA class I, HLA class II, HLA class III, PTPN22,
XBP1, IL2RA, LPP, RERE, FOXP1, TSLP, CCR6, GZMB, UBASH3A, C1QTNF6,
and FOXP3.
[0638] In some embodiments, treatment with the mitochondria' fission inhibitor
peptides (e.g., P110 and/or P110*) will prevent or delay the onset of one or
more of
the following symptoms: increased photosensitivity, decreased contact
sensitivity
response to dinitrochlorobenzene, depigmentation of the skin, mucous
membranes,
retina, or genitals, and premature whitening or graying of hair on the scalp,
eyelashes,
eyebrows or beard.
[0639] In some embodiments, treatment with the mitochondria' fission inhibitor
peptides (e.g., P110 and/or P110*) will prevent or delay the onset of one or
more of
the symptoms of IPF, including but not limited to, an increase in TGF-01-
induced
epithelial to mesenchymal transition (EMT), myofibroblast activation, collagen
production, lung scarring, and severe progressive fibrosis including fibrotic
foci and
honeycombing.
[0640] For therapeutic and/or prophylactic applications, a composition
comprising
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*), is
administered to
the subject. In some embodiments, the mitochondrial fission inhibitor peptide
composition (e.g., P110 and/or P110*) is administered one, two, three, four,
or five
times per day. In some embodiments, the mitochondrial fission inhibitor
peptide
composition (e.g., P110 and/or P110*) is administered more than five times per
day.
Additionally or alternatively, in some embodiments, the mitochondrial fission
inhibitor peptide composition (e.g., P110 and/or P110*) is administered every
day,
every other day, every third day, every fourth day, every fifth day, or every
sixth day.
In some embodiments, the mitochondrial fission inhibitor peptide composition
(e.g.,
P110 and/or P110*) is administered weekly, bi-weekly, tri-weekly, or monthly.
In
some embodiments, the mitochondrial fission inhibitor peptide composition
(e.g.,
P110 and/or P110*) is administered for a period of one, two, three, four, or
five
weeks. In some embodiments, the mitochondrial fission inhibitor peptide (e.g.,
P110
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and/or P110*) is administered for six weeks or more. In some embodiments, the
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) is
administered for
twelve weeks or more. In some embodiments, the mitochondrial fission inhibitor
peptide (e.g., P110 and/or P110*) is administered for a period of less than
one year.
In some embodiments, the mitochondrial fission inhibitor peptide (e.g., P110
and/or
P110*) is administered for a period of more than one year.
[0641] Additionally or alternatively, in some embodiments of the method, the
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) is
administered daily
for one, two, three, four or five weeks. In some embodiments of the method,
the
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) is
administered daily
for less than 6 weeks. In some embodiments of the method, the mitochondria'
fission
inhibitor peptide (e.g., P110 and/or P110*) is administered daily for 6 weeks
or more.
In other embodiments of the method, the mitochondrial fission inhibitor
peptide (e.g.,
P110 and/or P110*) is administered daily for 12 weeks or more.
Determination of the Biological Effect of the Mitochondrial Fission Inhibitor
Peptides
of the Present Technology
[0642] In various embodiments, suitable in vitro or in vivo assays are
performed to
determine the effect of a specific mitochondria' fission inhibitor peptide
(e.g., P110
and/or P110*) of the present technology and whether its administration is
indicated
for treatment. In various embodiments, in vitro assays can be performed with
representative animal models, to determine if a given mitochondrial fission
inhibitor
peptide-based therapeutic (e.g., P110 and/or P110*) exerts the desired effect
in
reducing disruption of mitochondrial function, such as disruption of OXPHOS,
or
alternatively treating a medical disease or condition, such as vitiligo,
Alport
Syndrome, porphyria or IPF. Compounds for use in therapy can be tested in
suitable
animal model systems including, but not limited to rats, mice, chicken, cows,
monkeys, rabbits, and the like, prior to testing in human subjects. Similarly,
for in
vivo testing, any of the animal model system known in the art can be used
prior to
administration to human subjects. In some embodiments, in vitro or in vivo
testing is
directed to the biological function of mitochondrial fission inhibitor
peptides of the
present technology (e.g., P110 and/or P110*).
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[0643] The mitochondrial fission inhibitor peptides of the present technology
(e.g.,
P110 and/or P110*) can be tested in vitro for efficacy. One such assay is
ability of a
compound to rescue FRDA fibroblasts stressed by addition of L-buthionine-(S,R)-
sulfoximine (BSO), as described in Jauslin et al., Hum. Mol. Genet.
11(24):3055
(2002), Jauslin etal., FASEB J. 17:1972-4 (2003), and International Patent
Application WO 2004/003565. Human dermal fibroblasts from Friedreich's Ataxia
patients have been shown to be hypersensitive to inhibition of the de novo
synthesis of
glutathione (GSH) with L-buthionine-(S,R)-sulfoximine (BSO), a specific
inhibitor of
GSH synthetase (Jauslin et al., Hum. Mol. Genet. 11(24):3055 (2002)). This
specific
BSO-mediated cell death can be prevented by administration of antioxidants or
molecules involved in the antioxidant pathway, such as a-tocopherol, short
chain
quinones, selenium, or small molecule glutathione peroxidase mimetics.
However,
antioxidants differ in their potency, i.e., the concentration at which they
are able to
rescue BSO-stressed FRDA fibroblasts. With this assay, EC50 concentrations of
the
compounds of the present technology can be determined and compared to known
reference antioxidants. Similar screens can be applied to fibroblasts derived
from
patients diagnosed as having, suspected as having, or at risk of having LHON,
Huntington's Disease, Parkinson's Disease, C0Q10 deficiencies, etc.
[0644] In some embodiments, disruption in oxidative phosphorylation is
determined
by assays well known in the art. By way of example, but not by way of
limitation, a
disruption in oxidative phosphorylation is determined by assays that measures
levels
of coenzyme Q10 (C0Q10). In some embodiments, disruption in oxidative
phosphorylation is determined by assays that measure OXPHOS capacity by the
uncoupling ratio. In some embodiments, disruption in oxidative phosphorylation
is
determined by assays that measure the net routine flux control ratio. In some
embodiments, disruption in oxidative phosphorylation is determined by assays
that
measure leak flux control ratio. In some embodiments, disruption in oxidative
phosphorylation is determined by assays that measure the phosphorylation
respiratory
control ratio.
[0645] Uncoupling ratio (UCR) is an expression of the respiratory reserve
capacity
and indicates the OXPHOS capacity of the cells. In some embodiments, UCR is
defined as Cr u / Cr. Cr u is the maximum rate of oxygen utilization (Oxygen
flux)
produced when mitochondria are chemically uncoupled using FCCP (Carbonyl
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CA 02881746 2015-02-13
cyanide 4-(trifluoromethoxy) phenylhydrazone). FCCP titration must be
performed
since the concentration of FCCP required to produce maximum oxygen utilization
varies among different cell lines. Once the maximum oxygen utilization is
reached,
further increases in FCCP inhibit oxygen utilization by oxidative
phosphorylation. In
some embodiments, Cr represents oxygen utilization by the cells during a
normal
cellular respiration with excess substrates.
[0646] In some embodiments, the Net Routine Flux Control Ratio (Cr! Cru) is
the
inverse of the UCR. In some embodiments, this value assesses how close routine
respiration operates to the respiratory capacity of oxidative phosphorylation.
[0647] In some embodiments, the Respiratory Control Ratio (RCR) is defined as
Cru
/ Cro. Cr u is defined above. Cro = Respiration after inhibition of Complex V
(ATP
synthase) by oligomycin. In some embodiments, this ratio allows assessment of
uncoupling and OXPHOS dysfunction.
[0648] In some embodiments, the Leak Flux Control Ratio is determined by Cro /
Cru. In some embodiments, this parameter is the inverse of RCR and represent
proton
leak with inhibition of ADP phosphorylation by oligomycin.
[0649] In some embodiments, the Phosphorylation Respiratory Control Ratio
(RCRp) is defined as (Cr ¨ CO/ Cr u (or 1/UCR ¨ 1/RCR). In some embodiments,
the
RCRp is an index which expresses phosphorylation-related respiration (Cr-
Cr()) as a
function of respiratory capacity (Cru). In some embodiments, the RCRp remains
constant, if partial uncoupling is fully compensated by an increased routine
respiration
rate and a constant rate of oxidative phosphorylation is maintained. In some
embodiments, if the respiratory capacity declines without effect on the rate
of
oxidative phosphorylation; in some embodiments, the RCRp increases, which
indicates that, a higher proportion of the maximum capacity is activated to
drive ATP
synthesis. In some embodiments, the RCRp declines to zero in either fully
uncoupled
cells or in cells under complete metabolic arrest.
[0650] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of subjects having mitochondrial disorder or disease, with a
mitochondrial
fission inhibitor peptide as disclosed herein, or a derivative, analogue, or
pharmaceutically acceptable salt thereof (e.g., P110 and/or P110*), will
reduce the
disruption in oxidative phosphorylation, thereby ameliorating symptoms of
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mitochondrial diseases and disorders. Symptoms of mitochondrial diseases or
disorders include, but are not limited to, poor growth, loss of muscle
coordination,
muscle weakness, neurological deficit, seizures, autism, autistic spectrum,
autistic-
like features, learning disabilities, heart disease, liver disease, kidney
disease,
gastrointestinal disorders, severe constipation, diabetes, increased risk of
infection,
thyroid dysfunction, adrenal dysfunction, autonomic dysfunction, confusion,
disorientation, memory loss, poor growth, failure to thrive, poor
coordination, sensory
(vision, hearing) problems, reduced mental functions, disease of the organ,
dementia,
respiratory problems, hypoglycemia, apnea, lactic acidosis, seizures,
swallowing
difficulties, developmental delays, movement disorders (dystonia, muscle
spasms,
tremors, chorea), stroke, brain atrophy, or any other sign or symptom of a
mitochondrial disease state disclosed herein.
[0651] Animal models of various diseases or conditions described herein (e.g.,
vitiligo, Alport Syndrome, IPF, porphyria) may be generated using techniques
known
in the art. Such models may be used to demonstrate the biological effect of
mitochondrial fission inhibitor peptides of the present technology (e.g., P110
and/or
P110*), in the prevention and treatment of conditions arising from disruption
of a
particular gene, and for determining what comprises a therapeutically
effective
amount of a mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*)
in a
given context.
[0652] In some embodiments, melanocyte degeneration is determined by assays
well known in the art. In some embodiments, melanocyte degeneration is
determined
by assays that measure cytotoxicity after epidermal cells are exposed to 100
or
250 M of 4-tertiary butyl phenol (4-TBP), a common inducer of vitiligo. In
some
embodiments, melanocyte degeneration is determined by assays that measure the
survival rate of epidermal cells that have been exposed to 100 or 25004 of 4-
TBP.
[0653] In some embodiments, melanocyte degeneration is determined by assays
that
measure melanocyte antigen-specific T cell accumulation and cytotoxic activity
in
autologous skin explants. For a detailed description of the autologous skin
explant
model, see Van Den Boom etal., Journal of Investigative Dermatology, 129: 2220-
2232 (2009).
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[0654] In some embodiments, melanocyte degeneration is determined by assays
that
measure the progressive depigmentation in the pelage of the vitiligo mouse
model
before and two weeks after plucking dorsal hairs. In some embodiments,
melanocyte
degeneration is determined by assays that measure the presence of ocular
pigmentation in vitiligo mice. In some embodiments, melanocyte degeneration is
determined by assays that measure the contact sensitivity of vitiligo mice to
dinitrochlorobenzene. For a detailed description of the vitiligo mouse model,
see
Lerner et al., Journal of Investigative Dermatology, 87(3): 299-304 (1986).
[0655] In some embodiments, melanocyte degeneration is determined by assays
that
measure epidermal depigmentation in an adoptive transfer mouse model of
vitiligo.
In some embodiments, melanocyte degeneration is determined by assays that
measure
tyrosinase RNA expression in an adoptive transfer mouse model of vitiligo. For
a
detailed description of the adoptive transfer mouse model of vitiligo, see
Harris et al.,
Journal of Investigative Dermatology, 132: 1869-1876 (2012).
[0656] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of subjects having vitiligo, with a mitochondrial fission inhibitor
peptide as
disclosed herein, or a derivative, analogue, or pharmaceutically acceptable
salt thereof
(e.g., P110 and/or P110*), will reduce melanocyte degeneration, thereby
ameliorating
symptoms of vitiligo. Symptoms of vitiligo include, but are not limited to,
increased
photosensitivity, decreased contact sensitivity response to
dinitrochlorobenzene,
depigmentation of the skin, mucous membranes, retina, or genitals, and
premature
whitening or graying of hair on the scalp, eyelashes, eyebrows or beard.
[0657] Animal models of Alport Syndrome may be generated using techniques
known in the art, including, for example by generating random or targeted
mutations
in one or more of COL4A3, COL4A4, and COL4A5. For example, murine models of
X-linked Alport Syndrome and autosomal recessive Alport Syndrome have been
generated by targeted disruption of the mouse Co14a5 gene and mouse Co14a3
gene
respectively. See Rheault et al., J Am Soc Nephrol. 15(6):1466-74 (2004);
Cosgrove
etal., Genes Dev. 10(23):2981-92 (1996).
[0658] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of subjects having Alport Syndrome, with a mitochondrial fission
inhibitor
peptide as disclosed herein, or a derivative, analogue, or pharmaceutically
acceptable
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CA 02881746 2015-02-13
salt thereof (e.g., P110 and/or P110*), will ameliorate symptoms of Alport
Syndrome.
Symptoms of Alport Syndrome include, but are not limited to, hematuria,
proteinuria,
cylindruria, leukocyturia, hypertension, edema, microalbuminuria, declining
glomerular filtration rate, fibrosis, GBM ultrastructural abnormalities,
nephrotic
syndrome, glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia, osteodystrophy, sensorineural deafness, anterior
lenticonus,
dot-and-fleck retinopathy, posterior polymorphous corneal dystrophy, recurrent
corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis.
[0659] Animals subjected to TGF-131-adenovirus-induced lung fibrosis or
bleomycin-induced lung fibrosis may be used as an in vivo model for IPF.
MacKinnon etal., Am. J. Respir. Crit. Care Med. 185(5):537-46 (2012).
[0660] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of subjects having IPF, with a mitochondrial fission inhibitor
peptide as
disclosed herein, or a derivative, analogue, or pharmaceutically acceptable
salt thereof
(e.g., P110 and/or P110*), will ameliorate symptoms of IPF.
[0661] Animal models of porphyria may be generated using techniques known in
the art, including, for example by generating random or targeted mutations in
one or
more genes encoding enzymes involved in heme biosynthesis. For example, a
murine
model of familial porphyria cutanea tarda has been generated by targeted
disruption of
the URO-D gene by homologous recombination.
[0662] Accordingly, in some embodiments, therapeutic and/or prophylactic
treatment of subjects having porphyria, with a mitochondrial fission inhibitor
peptide
as disclosed herein, or a derivative, analogue, or pharmaceutically acceptable
salt
thereof (e.g., P110 and/or P110*), will ameliorate symptoms of porphyria.
Symptoms
of porphyria include, but are not limited to, cutaneous lesions, blistering
skin lesions,
hypertrichosis, hyperpigmentation, thickening and/or scarring of the skin,
friability of
the skin, photosensitivity of the skin, lichenification, leathery
pseudovesicles, labial
grooving, nail changes, acute neurological attacks, abdominal pain and
cramping,
constipation, diarrhea, increased bowel sounds, decreased bowel sounds,
nausea,
vomiting, tachycardia, hypertension, headache, mental symptoms, extremity
pain,
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neck pain, chest pain, muscle weakness, sensory loss, tremors, sweating,
dysuria, and
bladder distension.
Use of Mitochondrial Fission Inhibitor Peptides of the Present Technology for
Modulation of Energy Biomarkers
[0663] In addition to monitoring energy biomarkers to assess the status of
treatment
or suppression of mitochondrial diseases, the mitochondrial fission inhibitor
peptides
of the present technology (e.g., P110 and/or P110*) can be used in subjects or
patients
to modulate one or more energy biomarkers. Modulation of energy biomarkers can
be
done to normalize energy biomarkers in a subject, or to enhance energy
biomarkers in
a subject.
[0664] Normalization of one or more energy biomarkers is defined as either
restoring the level of one or more such energy biomarkers to normal or near-
normal
levels in a subject whose levels of one or more energy biomarkers show
pathological
differences from normal levels (i.e., levels in a healthy subject), or to
change the
levels of one or more energy biomarkers to alleviate pathological symptoms in
a
subject. Depending on the nature of the energy biomarker, such levels may show
measured values either above or below a normal value. For example, a
pathological
lactate level is typically higher than the lactate level in a normal (i.e.,
healthy) person,
and a decrease in the level may be desirable. A pathological ATP level is
typically
lower than the ATP level in a normal (i.e., healthy) person, and an increase
in the
level of ATP may be desirable. Accordingly, normalization of energy biomarkers
can
involve restoring the level of energy biomarkers to within about at least two
standard
deviations of normal in a subject, or to within about at least one standard
deviation of
normal in a subject, to within about at least one-half standard deviation of
normal, or
to within about at least one-quarter standard deviation of normal.
[0665] When an increase in an energy biomarker level is desired to normalize
the
one or more such energy biomarker, the level of the energy biomarker can be
increased to within about at least two standard deviations of normal in a
subject,
increased to within about at least one standard deviation of normal in a
subject,
increased to within about at least one-half standard deviation of normal, or
increased
to within about at least one-quarter standard deviation of normal, by
administration of
one or more compounds according to the present technology. Alternatively, the
level
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of one or more of the energy biomarkers can be increased by about at least 10%
above
the subject's level of the respective one or more energy biomarkers before
administration; by about at least 20% above the subject's level of the
respective one or
more energy biomarkers before administration, by about at least 30% above the
subject's level of the respective one or more energy biomarkers before
administration,
by about at least 40% above the subject's level of the respective one or more
energy
biomarkers before administration, by about at least 50% above the subject's
level of
the respective one or more energy biomarkers before administration, by about
at least
75% above the subject's level of the respective one or more energy biomarkers
before
administration, or by about at least 100% above the subject's level of the
respective
one or more energy biomarkers before administration.
[0666] When a decrease in a level of one or more energy biomarkers is desired
to
normalize the one or more energy biomarkers, the level of the one or more
energy
biomarkers can be decreased to a level within about at least two standard
deviations of
normal in a subject, decreased to within about at least one standard deviation
of
normal in a subject, decreased to within about at least one-half standard
deviation of
normal, or decreased to within about at least one-quarter standard deviation
of normal,
by administration of one or more compounds according to the present
technology.
Alternatively, the level of the one or more energy biomarkers can be decreased
by
about at least 10% below the subject's level of the respective one or more
energy
biomarkers before administration, by about at least 20% below the subject's
level of
the respective one or more energy biomarkers before administration, by about
at least
30% below the subject's level of the respective one or more energy biomarkers
before
administration, by about at least 40% below the subject's level of the
respective one or
more energy biomarkers before administration, by about at least 50% below the
subject's level of the respective one or more energy biomarkers before
administration,
by about at least 75% below the subject's level of the respective one or more
energy
biomarkers before administration, or by about at least 90% below the subject's
level of
the respective one or more energy biomarkers before administration.
[0667] Enhancement of the level of one or more energy biomarkers is defined as
changing the extant levels of one or more energy biomarkers in a subject to a
level
which provides beneficial or desired effects for the subject. For example, a
person
undergoing strenuous effort or prolonged vigorous physical activity, such as
mountain
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climbing, could benefit from increased ATP levels or decreased lactate levels.
As
described above, normalization of energy biomarkers may not achieve the
optimum
state for a subject with a mitochondrial disease, and such subjects can also
benefit
from enhancement of energy biomarkers. Examples of subjects who could benefit
from enhanced levels of one or more energy biomarkers include, but are not
limited
to, subjects undergoing strenuous or prolonged physical activity, subjects
with chronic
energy problems, or subjects with chronic respiratory problems. Such subjects
include, but are not limited to, pregnant females, particularly pregnant
females in
labor; neonates, particularly premature neonates; subjects exposed to extreme
environments, such as hot environments (temperatures routinely exceeding about
85-
86 degrees Fahrenheit or about 30 degrees Celsius for about 4 hours daily or
more),
cold environments (temperatures routinely below about 32 degrees Fahrenheit or
about 0 degrees Celsius for about 4 hours daily or more), or environments with
lower-
than-average oxygen content, higher-than-average carbon dioxide content, or
higher-
than-average levels of air pollution (airline travelers, flight attendants,
subjects at
elevated altitudes, subjects living in cities with lower-than average air
quality,
subjects working in enclosed environments where air quality is degraded);
subjects
with lung diseases or lower-than-average lung capacity, such as tubercular
patients,
lung cancer patients, emphysema patients, and cystic fibrosis patients;
subjects
recovering from surgery or illness; elderly subjects, including elderly
subjects
experiencing decreased energy; subjects suffering from chronic fatigue,
including
chronic fatigue syndrome; subjects undergoing acute trauma; subjects in shock;
subjects requiring acute oxygen administration; subjects requiring chronic
oxygen
administration; or other subjects with acute, chronic, or ongoing energy
demands who
can benefit from enhancement of energy biomarkers.
[0668] In another embodiment of the present technology, including any of the
foregoing embodiments, the mitochondrial fission inhibitor peptides described
herein
(e.g., P110 and/or P110) are administered to subjects suffering from a
mitochondrial
disorder to modulate one or more of various energy biomarkers, including, but
not
limited to, lactic acid (lactate) levels (in one or more of whole blood,
plasma,
cerebrospinal fluid, or cerebral ventricular fluid); pyruvic acid (pyruvate)
levels (in
one or more of whole blood, plasma, cerebrospinal fluid, or cerebral
ventricular
fluid); lactate/pyruvate ratios (in one or more of whole blood, plasma,
cerebrospinal
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CA 02881746 2015-02-13
fluid, or cerebral ventricular fluid); total, reduced or oxidized glutathione
levels, or
reduced/oxidized glutathione ratios (in one or more of whole blood, plasma,
lymphocytes, cerebrospinal fluid, or cerebral ventricular fluid); total,
reduced or
oxidized cysteine levels, or reduced/oxidized cysteine ratios (in one or more
of whole
blood, plasma, lymphocytes, cerebrospinal fluid, or cerebral ventricular
fluid);
phosphocreatine levels; NADH (NADH+H30) or NADPH (NADPH+H30 ) levels;
NAD or NADP levels; ATP levels; reduced coenzyme Q (CoQred) levels; oxidized
coenzyme Q (CoQox) levels; total coenzyme Q (CoQtot) levels; oxidized
cytochrome
C levels; reduced cytochrome C levels; oxidized cytochrome C/reduced
cytochrome C
ratio; acetoacetate levels; beta-hydroxy butyrate levels; acetoacetate/ beta-
hydroxy
butyrate ratio; 8-hydroxy-2'-deoxyguanosine (8-0HdG) levels; levels of
reactive
oxygen species; oxygen consumption (V02), carbon dioxide output (VCO2),
respiratory quotient (VCO2/V02), and to modulate exercise intolerance (or
conversely, modulate exercise tolerance) and to modulate anaerobic threshold.
Energy biomarkers can be measured in whole blood, plasma, cerebrospinal fluid,
cerebroventricular fluid, arterial blood, venous blood, or any other body
fluid, body
gas, or other biological sample useful for such measurement. In one
embodiment, the
levels are modulated to a value within about 2 standard deviations of the
value in a
healthy subject. In another embodiment, the levels are modulated to a value
within
about 1 standard deviation of the value in a healthy subject. In another
embodiment,
the levels in a subject are changed by at least about 10% above or below the
level in
the subject prior to modulation. In another embodiment, the levels are changed
by at
least about 20% above or below the level in the subject prior to modulation.
In
another embodiment, the levels are changed by at least about 30% above or
below the
level in the subject prior to modulation. In another embodiment, the levels
are
changed by at least about 40% above or below the level in the subject prior to
modulation. In another embodiment, the levels are changed by at least about
50%
above or below the level in the subject prior to modulation. In another
embodiment,
the levels are changed by at least about 75% above or below the level in the
subject
prior to modulation. In another embodiment, the levels are changed by at least
about
100% above or at least about 90% below the level in the subject prior to
modulation.
106691 Several metabolic biomarkers have already been used to evaluate
efficacy of
CoQ10, and these metabolic biomarkers can be monitored as energy biomarkers
for
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use in the methods of the present technology. Pyruvate, a product of the
anaerobic
metabolism of glucose, is removed by reduction to lactic acid in an anaerobic
setting
or by oxidative metabolism, which is dependent on a functional mitochondrial
respiratory chain. Dysfunction of the respiratory chain may lead to inadequate
removal of lactate and pyruvate from the circulation and elevated
lactate/pyruvate
ratios are observed in mitochondrial cytopathies (see Scriver C R, The
Metabolic and
Molecular Bases of Inherited Disease, 7th ed., New York: McGraw-Hill, Health
Professions Division, 1995; and Munnich et at., J. Inherit. Metab. Dis.
15(4):448-55
(1992)). Blood lactate/pyruvate ratio (Chariot et al., Arch. Pathol. Lab. Med.
118(7):695-7 (1994)) is, therefore, widely used as a noninvasive test for
detection of
mitochondrial cytopathies (see again Scriver C R, The Metabolic and Molecular
Bases of Inherited Disease, 7th ed., New York: McGraw-Hill, Health Professions
Division, 1995; and Munnich et at., J. Inherit. Metab. Dis. 15(4):448-55
(1992)) and
toxic mitochondrial myopathies (Chariot et at., Arthritis Rheum. 37(4):583-6
(1994)).
Changes in the redox state of liver mitochondria can be investigated by
measuring the
arterial ketone body ratio (acetoacetate/3-hydroxybutyrate: AKBR) (Ueda et
al., J.
Cardiol. 29(2):95-102 (1997)). Urinary excretion of 8-hydroxy-2'-
deoxyguanosine
(8-0HdG) often has been used as a biomarker to assess the extent of repair of
ROS-
induced DNA damage in both clinical and occupational settings (Erhola et at.,
FEBS
Lett. 409(2):287-91 (1997); Honda et al., Leuk. Res. 24(6):461-8 (2000);
Pilger et al.,
Free Radic. Res. 35(3):273-80 (2001); Kim et al. Environ Health Perspect
112(6):666-71 (2004)).
[0670] Magnetic resonance spectroscopy (MRS) has been useful in the diagnoses
of
mitochondrial cytopathy by demonstrating elevations in cerebrospinal fluid
(CSF) and
cortical white matter lactate using proton MRS (1H-MRS) (Kaufmann et al.,
Neurology 62(8):1297-302 (2004)). Phosphorous MRS (31P-MRS) has been used to
demonstrate low levels of cortical phosphocreatine (PCr) (Matthews et al.,
Ann.
Neurol. 29(4):435-8 (1991)), and a delay in PCr recovery kinetics following
exercise
in skeletal muscle (Matthews et al., Ann. Neurol. 29(4):435-8 (1991);
Barbiroli etal.,
Neurol. 242(7):472-7 (1995); Fabrizi et al., J. Neurol. Sci. 137(1):20-7
(1996)). A
low skeletal muscle PCr has also been confirmed in patients with mitochondrial
cytopathy by direct biochemical measurements.
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[0671] Exercise testing is particularly helpful as an evaluation and screening
tool in
mitochondrial myopathies. One of the hallmark characteristics of mitochondrial
myopathies is a reduction in maximal whole body oxygen consumption (V02max)
(Taivassalo et al., Brain 126(Pt 2):413-23 (2003)). Given that VO2max is
determined
by cardiac output (Qc) and peripheral oxygen extraction (arterial-venous total
oxygen
content) difference, some mitochondrial cytopathies affect cardiac function
where
delivery can be altered; however, most mitochondrial myopathies show a
characteristic deficit in peripheral oxygen extraction (A-V02 difference) and
an
enhanced oxygen delivery (hyperkinetic circulation) (Taivassalo et al., Brain
126(Pt
2):413-23 (2003)). This can be demonstrated by a lack of exercise induced
deoxygenation of venous blood with direct AV balance measurements (Taivassalo
et
al., Ann. Neurol. 51(1):38-44 (2002)) and non-invasively by near infrared
spectroscopy (Lynch et al., Muscle Nerve 25(5):664-73 (2002); van Beekvelt et
al.,
Ann. Neurol. 46(4):667-70 (1999)).
[0672] Several of these energy biomarkers are discussed in more detail as
follows.
It should be emphasized that, while certain energy biomarkers are discussed
and
enumerated herein, the present technology is not limited to modulation,
normalization
or enhancement of only these enumerated energy biomarkers.
[0673] Lactic acid (lactate) levels: Mitochondrial dysfunction typically
results in
abnormal levels of lactic acid, as pyruvate levels increase and pyruvate is
converted to
lactate to maintain capacity for glycolysis. Mitochondrial dysfunction can
also result
in abnormal levels of NADH+H30, NADPH+H30, NAD, or NADP, as the reduced
nicotinamide adenine dinucleotides are not efficiently processed by the
respiratory
chain. Lactate levels can be measured by taking samples of appropriate bodily
fluids
such as whole blood, plasma, or cerebrospinal fluid. Using magnetic resonance,
lactate levels can be measured in virtually any volume of the body desired,
such as the
brain.
[0674] Measurement of cerebral lactic acidosis using magnetic resonance in
patients
is described in Kaufmann et al., Neurology 62(8): 1297 (2004). Whole blood,
plasma,
and cerebrospinal fluid lactate levels can be measured by commercially
available
equipment such as the YSI 2300 STAT Plus Glucose & Lactate Analyzer (YSI Life
Sciences, Ohio).
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[0675] NAD, NADP, NADH and NADPH levels: Measurement of NAD, NADP,
NADH (NADH+H3 ) or NADPH (NADPH+H3 ) can be measured by a variety of
fluorescent, enzymatic, or electrochemical techniques, e.g., the
electrochemical assay
described in US 2005/0067303.
[0676] Oxygen consumption (v02 or V02), carbon dioxide output (vCO2 or VCO2),
and respiratory quotient (VCO2NO2): v02 is usually measured either while
resting
(resting v02) or at maximal exercise intensity (v02 max). Optimally, both
values will
be measured. However, for severely disabled patients, measurement of v02 max
may
be impractical. Measurement of both forms of v02 is readily accomplished using
standard equipment from a variety of vendors, e.g., Korr Medical Technologies,
Inc.
(Salt Lake City, Utah). VCO2 can also be readily measured, and the ratio of
VCO2 to
V02 under the same conditions (VCO2/V02, either resting or at maximal exercise
intensity) provides the respiratory quotient (RQ).
[0677] Oxidized Cytochrome C, reduced Cytochrome C, and ratio of oxidized
Cytochrome C to reduced Cytochrome C: Cytochrome C parameters, such as
oxidized
cytochrome C levels (Cyt Cox), reduced cytochrome C levels (Cyt Cred), and the
ratio
of oxidized cytochrome C/reduced cytochrome C ratio (Cyt Cox)/(Cyt Cred), can
be
measured by in vivo near infrared spectroscopy. See, e.g., Rolfe, P., "In vivo
near-
infrared spectroscopy," Annu. Rev. Biomed. Eng. 2:715-54 (2000) and Strangman
et
al., "Non-invasive neuroimaging using near-infrared light" Biol. Psychiatry
52:679-93
(2002).
[0678] Exercise tolerance/Exercise intolerance: Exercise intolerance is
defined as
"the reduced ability to perform activities that involve dynamic movement of
large
skeletal muscles because of symptoms of dyspnea or fatigue" (Pina et al.,
Circulation
107:1210 (2003)). Exercise intolerance is often accompanied by myoglobinuria,
due
to breakdown of muscle tissue and subsequent excretion of muscle myoglobin in
the
urine. Various measures of exercise intolerance can be used, such as time
spent
walking or running on a treadmill before exhaustion, time spent on an exercise
bicycle
(stationary bicycle) before exhaustion, and the like. Treatment with the
compositions
or methods of the present technology can result in about a 10% or greater
improvement in exercise tolerance (for example, about a 10% or greater
increase in
time to exhaustion, e.g., from 10 minutes to 11 minutes), about a 20% or
greater
improvement in exercise tolerance, about a 30% or greater improvement in
exercise
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tolerance, about a 40% or greater improvement in exercise tolerance, about a
50% or
greater improvement in exercise tolerance, about a 75% or greater improvement
in
exercise tolerance, or about a 100% or greater improvement in exercise
tolerance.
While exercise tolerance is not, strictly speaking, an energy biomarker, for
the
purposes of the present technology, modulation, normalization, or enhancement
of
energy biomarkers includes modulation, normalization, or enhancement of
exercise
tolerance.
[0679] Similarly, tests for normal and abnormal values of pyruvic acid
(pyruvate)
levels, lactate/pyruvate ratio, ATP levels, anaerobic threshold, reduced
coenzyme Q
(CoQ'd) levels, oxidized coenzyme Q (CoQ x) levels, total coenzyme Q (CoQt0t)
levels, oxidized cytochrome C levels, reduced cytochrome C levels, oxidized
cytochrome C/reduced cytochrome C ratio, acetoacetate levels, 0-hydroxy
butyrate
levels, acetoacetate/13-hydroxy butyrate ratio, 8-hydroxy-2'-deoxyguanosine (8-
OHdG) levels, and levels of reactive oxygen species are known in the art and
can be
used to evaluate efficacy of the compositions and methods of the present
technology.
(For the purposes of the present technology, modulation, normalization, or
enhancement of energy biomarkers includes modulation, normalization, or
enhancement of anaerobic threshold.)
[0680] Neuroimaging is indicated in individuals with suspected CNS disease. CT
may show basal ganglia calcification and/or diffuse atrophy. MRI may show
focal
atrophy of the cortex or cerebellum, or high signal change on T2-weighted
images,
particularly in the occipital cortex. There may also be evidence of a
generalized
leukoencephalopathy. Cerebellar atrophy is a prominent feature in children.
[0681] Electroencephalography (EEG) is indicated in individuals with suspected
encephalopathy or seizures. Encephalopathy may be associated with generalized
slow
wave activity on the EEG. Generalized or focal spike and wave discharges may
be
seen in individuals with seizures.
[0682] Peripheral neurophysiologic studies are indicated in individuals with
limb
weakness, sensory symptoms, or areflexia. Electromyography (EMG) is often
normal
but may show myopathic features. Nerve conduction velocity (NCV) may be normal
or may show a predominantly axonal sensorimotor polyneuropathy.
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CA 02881746 2015-02-13
[0683] Magnetic resonance spectroscopy (MRS) and exercise testing (with
measurement of blood concentration of lactate) may be used to detect evidence
of
abnormal mitochondrial function non-invasively.
[0684] Glucose. An elevated concentration of fasting blood glucose may
indicate
diabetes mellitus.
[0685] Cardiac. Both electrocardiography and echocardiography may indicate
cardiac involvement (cardiomyopathy or atrioventricular conduction defects).
[0686] Treatment of a subject afflicted by a mitochondrial disease in
accordance
with the methods of the present technology may result in the inducement of a
reduction or alleviation of symptoms in the subject, e.g., to halt the further
progression of the disorder. Partial or complete suppression of the
mitochondrial
disease can result in a lessening of the severity of one or more of the
symptoms that
the subject would otherwise experience.
[0687] Any one, or any combination of, the energy biomarkers described herein
(e.g., Figure 1) provide conveniently measurable benchmarks by which to gauge
the
effectiveness of treatment or suppressive therapy. Additionally, other energy
biomarkers are known to those skilled in the art and can be monitored to
evaluate the
efficacy of treatment or suppressive therapy.
Modes of Administration and Effective Dosages
[0688] Any method known to those in the art for contacting a cell, organ or
tissue
with a mitochondrial fission inhibitor peptide of the present technology, or a
derivative, analogue, or pharmaceutically acceptable salt thereof (e.g., P110
and/or
P110*), may be employed. Suitable methods include in vitro, ex vivo, or in
vivo
methods. In vivo methods typically include the administration of a
mitochondrial
fission inhibitor peptide (e.g., P110 and/or P110*) to a mammal, suitably a
human.
When used in vivo for therapy, the mitochondrial fission inhibitor peptides
(e.g., P110
and/or P110*) are administered to the subject in effective amounts (i.e.,
amounts that
have desired therapeutic effect). The dose and dosage regimen will depend upon
the
degree of the infection in the subject, the characteristics of the particular
mitochondrial fission inhibitor peptide used (e.g., P110 and/or P110*), such
as its
therapeutic index, the subject, and the subject's history.
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[0689] The effective amount may be determined during pre-clinical trials and
clinical trials by methods familiar to physicians and clinicians. An effective
amount
of mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) useful
in the
methods may be administered to a mammal in need thereof by any of a number of
well-known methods for administering pharmaceutical compounds. The
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) may be
administered systemically or locally.
[0690] The mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*)
may
be formulated as a pharmaceutically acceptable salt. The term
"pharmaceutically
acceptable salt" means a salt prepared from a base or an acid which is
acceptable for
administration to a patient, such as a mammal (e.g., salts having acceptable
mammalian safety for a given dosage regime). However, it is understood that
the
salts are not required to be pharmaceutically acceptable salts, such as salts
of
intermediate compounds that are not intended for administration to a patient.
Pharmaceutically acceptable salts can be derived from pharmaceutically
acceptable
inorganic or organic bases and from pharmaceutically acceptable inorganic or
organic
acids. In addition, when a mitochondrial fission inhibitor peptide (e.g., P110
and/or
P110*) contains both a basic moiety, such as an amine, pyridine or imidazole,
and an
acidic moiety such as a carboxylic acid or tetrazole, zwitterions may be
formed and
are included within the term "salt" as used herein. Salts derived from
pharmaceutically acceptable inorganic bases include ammonium, calcium, copper,
ferric, ferrous, lithium, magnesium, manganic, manganous, potassium, sodium,
and
zinc salts, and the like. Salts derived from pharmaceutically acceptable
organic bases
include salts of primary, secondary and tertiary amines, including substituted
amines,
cyclic amines, naturally-occurring amines and the like, such as arginine,
betaine,
caffeine, choline, N,N'-dibenzylethylenediamine, diethylamine, 2-
diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-
ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine,
hydrabamine,
isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperadine,
polyamine resins, procaine, purines, theobromine, triethylamine,
trimethylamine,
tripropylamine, tromethamine and the like. Salts derived from pharmaceutically
acceptable inorganic acids include salts of boric, carbonic, hydrohalic
(hydrobromic,
hydrochloric, hydrofluoric or hydroiodic), nitric, phosphoric, sulfamic and
sulfuric
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acids. Salts derived from pharmaceutically acceptable organic acids include
salts of
aliphatic hydroxyl acids (e.g., citric, gluconic, glycolic, lactic,
lactobionic, malic, and
tartaric acids), aliphatic monocarboxylic acids (e.g., acetic, butyric,
formic, propionic
and trifluoroacetic acids), amino acids (e.g., aspartic and glutamic acids),
aromatic
carboxylic acids (e.g., benzoic, p-chlorobenzoic, diphenylacetic, gentisic,
hippuric,
and triphenylacetic acids), aromatic hydroxyl acids (e.g., o-hydroxybenzoic, p-
hydroxybenzoic, 1-hydroxynaphthalene-2-carboxylic and 3-hydroxynaphthalene-2-
carboxylic acids), ascorbic, dicarboxylic acids (e.g., fiimaric, maleic,
oxalic and
succinic acids), glucuronic, mandelic, mucic, nicotinic, orotic, pamoic,
pantothenic,
sulfonic acids (e.g., benzenesulfonic, camphosulfonic, edisylic,
ethanesulfonic,
isethionic, methanesulfonic, naphthalenesulfonic, naphthalene-1,5-disulfonic,
naphthalene-2,6-disulfonic and p-toluenesulfonic acids), xinafoic acid, and
the like.
[0691] The mitochondrial fission inhibitor peptides of the present technology
(e.g.,
P110 and/or P110*), can be incorporated into pharmaceutical compositions for
administration, singly or in combination, to a subject for the treatment or
prevention
of a disorder described herein. Such compositions typically include the active
agent
and a pharmaceutically acceptable carrier. As used herein the term
"pharmaceutically
acceptable carrier" includes saline, solvents, dispersion media, coatings,
antibacterial
and antifungal agents, isotonic and absorption delaying agents, and the like,
compatible with pharmaceutical administration. Supplementary active compounds
can also be incorporated into the compositions.
[0692] Pharmaceutical compositions are typically formulated to be compatible
with
its intended route of administration. Examples of routes of administration
include
parenteral (e.g., intravenous, intradermal, intraperitoneal or subcutaneous),
oral,
inhalation, intrathecal, transdermal (topical), intraocular, iontophoretic,
and
transmucosal administration. Solutions or suspensions used for parenteral,
intradermal, or subcutaneous application can include the following components:
a
sterile diluent such as water for injection, saline solution, fixed oils,
polyethylene
glycols, glycerine, propylene glycol or other synthetic solvents;
antibacterial agents
such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid
or
sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid;
buffers
such as acetates, citrates or phosphates and agents for the adjustment of
tonicity such
as sodium chloride or dextrose. pH can be adjusted with acids or bases, such
as
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CA 02881746 2015-02-13
hydrochloric acid or sodium hydroxide. The parenteral preparation can be
enclosed in
ampoules, disposable syringes or multiple dose vials made of glass or plastic.
For
convenience of the patient or treating physician, the dosing formulation can
be
provided in a kit containing all necessary equipment (e.g., vials of drug,
vials of
diluent, syringes and needles) for a treatment course (e.g., 7 days of
treatment).
[0693] Pharmaceutical compositions suitable for injectable use can include
sterile
aqueous solutions (where water soluble) or dispersions and sterile powders for
the
extemporaneous preparation of sterile injectable solutions or dispersion. For
intravenous administration, suitable carriers include physiological saline,
bacteriostatic water, Cremophor ELTM (BASF, Parsippany, N.J.) or phosphate
buffered saline (PBS). In all cases, a composition for parenteral
administration must
be sterile and should be fluid to the extent that easy syringability exists.
It should be
stable under the conditions of manufacture and storage and must be preserved
against
the contaminating action of microorganisms such as bacteria and fungi.
[0694] The mitochondrial fission inhibitor peptide compositions (e.g., P110
and/or
P110*) can include a carrier, which can be a solvent or dispersion medium
containing,
for example, water, ethanol, polyol (for example, glycerol, propylene glycol,
and
liquid polyethylene glycol, and the like), and suitable mixtures thereof The
proper
fluidity can be maintained, for example, by the use of a coating such as
lecithin, by
the maintenance of the required particle size in the case of dispersion and by
the use
of surfactants. Prevention of the action of microorganisms can be achieved by
various
antibacterial and antifungal agents, for example, parabens, chlorobutanol,
phenol,
ascorbic acid, thiomerasol, and the like. Glutathione and other antioxidants
can be
included to prevent oxidation. In some embodiments, the mitochondrial fission
inhibitor peptide compositions (e.g., P110 and/or P110*) include isotonic
agents, for
example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride
in the
composition. Prolonged absorption of the injectable compositions can be
brought
about by including in the composition an agent that delays absorption, for
example,
aluminum monostearate or gelatin.
[0695] Sterile injectable solutions can be prepared by incorporating the
active
compound in the required amount in an appropriate solvent with one or a
combination
of ingredients enumerated above, as required, followed by filtered
sterilization.
Generally, dispersions are prepared by incorporating the active compound into
a
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CA 02881746 2015-02-13
sterile vehicle, which contains a basic dispersion medium and the required
other
ingredients from those enumerated above. In the case of sterile powders for
the
preparation of sterile injectable solutions, typical methods of preparation
include
vacuum drying and freeze drying, which can yield a powder of the active
ingredient
plus any additional desired ingredient from a previously sterile-filtered
solution
thereof
[0696] Oral compositions generally include an inert diluent or an edible
carrier. For
the purpose of oral therapeutic administration, the active compound can be
incorporated with excipients and used in the form of tablets, troches, or
capsules, e.g.,
gelatin capsules. Oral compositions can also be prepared using a fluid carrier
for use
as a mouthwash. Pharmaceutically compatible binding agents, and/or adjuvant
materials can be included as part of the composition. The tablets, pills,
capsules,
troches and the like can contain any of the following ingredients, or
compounds of a
similar nature: a binder such as microcrystalline cellulose, gum tragacanth or
gelatin;
an excipient such as starch or lactose, a disintegrating agent such as alginic
acid,
Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes;
a glidant
such as colloidal silicon dioxide; a sweetening agent such as sucrose or
saccharin; or a
flavoring agent such as peppermint, methyl salicylate, or orange flavoring.
[0697] For administration by inhalation, the compounds can be delivered in the
form of an aerosol spray from a pressurized container or dispenser, which
contains a
suitable propellant, e.g., a gas such as carbon dioxide, or a nebulizer. Such
methods
include those described in U.S. Pat. No. 6,468,798.
[0698] Systemic administration of a therapeutic compound as described herein
can
also be by transmucosal or transdermal means. For transmucosal or transdermal
administration, penetrants appropriate to the barrier to be permeated are used
in the
formulation. Such penetrants are generally known in the art, and include, for
example, for transmucosal administration, detergents, bile salts, and fusidic
acid
derivatives. Transmucosal administration can be accomplished through the use
of
nasal sprays. For transdermal administration, the active compounds are
formulated
into ointments, salves, gels, or creams as generally known in the art. In one
embodiment, transdermal administration may be performed by iontophoresis.
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[0699] A therapeutic mitochondrial fission inhibitor peptide (e.g., P110
and/or
P110*) can be formulated in a carrier system. The carrier can be a colloidal
system.
The colloidal system can be a liposome, a phospholipid bilayer vehicle. In one
embodiment, the therapeutic mitochondrial fission inhibitor peptide (e.g.,
P110 and/or
P110*) is encapsulated in a liposome while maintaining its structural
integrity. As
one skilled in the art would appreciate, there are a variety of methods to
prepare
liposomes. (See Lichtenberg, et at., Methods Biochem. Anal., 33:337-462
(1988);
Anselem, et al., Liposome Technology, CRC Press (1993)). Liposomal
formulations
can delay clearance and increase cellular uptake (See Reddy, Ann.
Pharmacother.,
34(7-8):915-923 (2000)). An active agent can also be loaded into a particle
prepared
from pharmaceutically acceptable ingredients including, but not limited to,
soluble,
insoluble, permeable, impermeable, biodegradable or gastroretentive polymers
or
liposomes. Such particles include, but are not limited to, nanoparticles,
biodegradable
nanoparticles, microparticles, biodegradable microparticles, nanospheres,
biodegradable nanospheres, microspheres, biodegradable microspheres, capsules,
emulsions, liposomes, micelles and viral vector systems.
[0700] The carrier can also be a polymer, e.g., a biodegradable, biocompatible
polymer matrix. In one embodiment, the therapeutic mitochondrial fission
inhibitor
peptide (e.g., P110 and/or P110*) can be embedded in the polymer matrix, while
maintaining protein integrity. The polymer may be natural, such as
polysaccharides,
or synthetic, such as poly a-hydroxy acids. Examples include carriers made of,
e.g.,
collagen, fibronectin, elastin, cellulose acetate, cellulose nitrate,
polysaccharide,
fibrin, gelatin, and combinations thereof. In one embodiment, the polymer is
poly-
lactic acid (PLA) or copoly lactic/glycolic acid (PGLA). The polymeric
matrices can
be prepared and isolated in a variety of forms and sizes, including
microspheres and
nanospheres. Polymer formulations can lead to prolonged duration of
therapeutic
effect. (See Reddy, Ann. Pharmacother., 34(7-8):915-923 (2000)). A polymer
formulation for human growth hormone (hGH) has been used in clinical trials.
(See
Kozarich and Rich, Chemical Biology, 2:548-552 (1998)).
[0701] Examples of polymer microsphere sustained release formulations are
described in PCT publication WO 99/15154 (Tracy, et at.), U.S. Pat. Nos.
5,674,534
and 5,716,644 (both to Zale, et al.), PCT publication WO 96/40073 (Zale, et
al.), and
PCT publication WO 00/38651 (Shah, et al.). U.S. Pat. Nos. 5,674,534 and
5,716,644
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and PCT publication WO 96/40073 describe a polymeric matrix containing
particles
of erythropoietin that are stabilized against aggregation with a salt.
[0702] In some embodiments, the therapeutic compounds are prepared with
carriers
that will protect the therapeutic compounds against rapid elimination from the
body,
such as a controlled release formulation, including implants and
microencapsulated
delivery systems. Biodegradable, biocompatible polymers can be used, such as
ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen,
polyorthoesters,
and polylactic acid. Such formulations can be prepared using known techniques.
The materials can also be obtained commercially, e.g., from Alza Corporation
and
Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeted
to
specific cells with monoclonal antibodies to cell-specific antigens) can also
be used as
pharmaceutically acceptable carriers. These can be prepared according to
methods
known to those skilled in the art, for example, as described in U.S. Pat. No.
4,522,811.
[0703] The therapeutic compounds can also be formulated to enhance
intracellular
delivery. For example, liposomal delivery systems are known in the art, see,
e.g.,
Chonn and Cullis, "Recent Advances in Liposome Drug Delivery Systems," Current
Opinion in Biotechnology 6:698-708 (1995); Weiner, "Liposomes for Protein
Delivery: Selecting Manufacture and Development Processes," Immunomethods,
4(3):201-9 (1994); and Gregoriadis, "Engineering Liposomes for Drug Delivery:
Progress and Problems," Trends Biotechnol., 13(12):527-37 (1995). Mizguchi,
etal.,
Cancer Lett., 100:63-69 (1996), describes the use of fusogenic liposomes to
deliver a
protein to cells both in vivo and in vitro.
[0704] Dosage, toxicity and therapeutic efficacy of the therapeutic agents can
be
determined by standard pharmaceutical procedures in cell cultures or
experimental
animals, e.g., for determining the LD50 (the dose lethal to 50% of the
population) and
the ED50 (the dose therapeutically effective in 50% of the population). The
dose
ratio between toxic and therapeutic effects is the therapeutic index and it
can be
expressed as the ratio LD50/ED50. Compounds that exhibit high therapeutic
indices
are preferred. While compounds that exhibit toxic side effects may be used,
care
should be taken to design a delivery system that targets such compounds to the
site of
affected tissue in order to minimize potential damage to uninfected cells and,
thereby,
reduce side effects.
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[0705] The data obtained from the cell culture assays and animal studies can
be
used in formulating a range of dosage for use in humans. In some embodiments,
the
dosage of such compounds lies within a range of circulating concentrations
that
include the ED50 with little or no toxicity. The dosage may vary within this
range
depending upon the dosage form employed and the route of administration
utilized.
For any compound used in the methods, the therapeutically effective dose can
be
estimated initially from cell culture assays. A dose can be formulated in
animal
models to achieve a circulating plasma concentration range that includes the
IC50
(i.e., the concentration of the test compound which achieves a half-maximal
inhibition
of symptoms) as determined in cell culture. Such information can be used to
determine useful doses in humans accurately. Levels in plasma may be measured,
for
example, by high performance liquid chromatography.
[0706] Typically, an effective amount of the mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*), sufficient for achieving a therapeutic or
prophylactic effect,
ranges from about 0.000001 mg per kilogram body weight per day to about 10,000
mg per kilogram body weight per day. Suitably, the dosage ranges are from
about
0.0001 mg per kilogram body weight per day to about 100 mg per kilogram body
weight per day. For example dosages can be 1 mg/kg body weight or 10 mg/kg
body
weight every day, every two days or every three days or within the range of 1-
10
mg/kg every week, every two weeks or every three weeks. In one embodiment, a
single dosage of mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*)
ranges from 0.001-10,000 micrograms per kg body weight. In one embodiment,
mitochondrial fission inhibitor peptide concentrations (e.g., P110 and/or
P110*) in a
carrier range from 0.2 to 2000 micrograms per delivered milliliter. An
exemplary
treatment regime entails administration once per day or once a week. In
therapeutic
applications, a relatively high dosage at relatively short intervals is
sometimes
required until progression of the disease is reduced or terminated, and in
certain
embodiments, until the subject shows partial or complete amelioration of
symptoms
of disease. Thereafter, the patient can be administered a prophylactic regime.
[0707] In some embodiments, a therapeutically effective amount of a
mitochondrial
fission inhibitor peptide (e.g., P110 and/or P110*) may be defined as a
concentration
of a mitochondrial fission inhibitor peptide at the target tissue of 10-12 to
10-6 molar,
e.g., approximately 10-7 molar. This concentration may be delivered by
systemic
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doses of 0.001 to 100 mg/kg or equivalent dose by body surface area. In some
embodiments, the schedule of doses would be optimized to maintain the
therapeutic
concentration at the target tissue, by single daily or weekly administration,
but also
including continuous administration (e.g., parenteral infusion or transdermal
application).
[0708] The skilled artisan will appreciate that certain factors may influence
the
dosage and timing required to effectively treat a subject, including but not
limited to,
the severity of the disease or disorder, previous treatments, the general
health and/or
age of the subject, and other diseases present. Moreover, treatment of a
subject with a
therapeutically effective amount of the therapeutic compositions described
herein can
include a single treatment or a series of treatments.
[0709] The mammal treated in accordance present methods can be any mammal,
including, for example, farm animals, such as sheep, pigs, cows, and horses;
pet
animals, such as dogs and cats; laboratory animals, such as rats, mice and
rabbits. In
one embodiment, the mammal is a human.
Combination Therapy with Mitochondrial Fission Inhibitor Peptides and Other
Therapeutic Agents
[0710] In one embodiment, an additional therapeutic agent is administered to a
subject in combination with a mitochondrial fission inhibitor peptide of the
present
technology (e.g., P110 and/or P110*), such that a synergistic therapeutic
effect is
produced. In one embodiment, the administration of the mitochonthial fission
inhibitor peptide (e.g., P110 and/or P110*) in combination with an additional
therapeutic agent "primes" the tissue, so that it is more responsive to the
therapeutic
effects of one or more therapeutic agents.
[0711] In any case, the multiple therapeutic agents may be administered in any
order. In some embodiments, the subject is administered multiple therapeutic
agents
simultaneously, separately, or sequentially. If simultaneously, the multiple
therapeutic agents may be provided in a single, unified form, or in multiple
forms (by
way of example only, either as a single pill or as two separate pills). One of
the
therapeutic agents may be given in multiple doses, or both may be given as
multiple
doses. If not simultaneous, the timing between the multiple doses may vary
from
more than zero weeks to less than four weeks. In some embodiments, the
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mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) is
administered prior
to or subsequent to additional therapeutic agent. In some embodiments, the
subject is
administered the multiple therapeutic agents before the signs, symptoms or
complications of a disease or condition are evident. In addition, the
combination
methods, compositions and formulations are not to be limited to the use of
only two
agents.
[0712] By way of example, but not by way of limitation, the treatment for
mitochondrial diseases or disorders typically involves taking vitamins and
cofactors.
In addition, antibiotics, hormones, antineoplastic agents, steroids,
immunomodulators,
dermatologic drugs, antithrombotic, antianemic, and cardiovascular agents, by
way of
non-limiting example, may also be administered.
[0713] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) are combined with one or more cofactors,
vitamins, iron chelators, antioxidants, frataxin level modifiers, ACE
inhibitors and 0-
blockers. By way of example, but not by way of limitation, such compounds may
include one or more of CoQ10, Levocarnitine, riboflavin, acetyl-L-carnitine,
thiamine,
nicotinamide, vitamin E, vitamin C, lipoic acid, selenium, 0-carotene, biotin,
folic
acid, calcium, magnesium, phosphorous, succinate, selenium, creatine, uridine,
citratesm prednisone, vitamin K, deferoxamine, deferiprone, idebenone,
erythropoietin, 170-estradiol, methylene blue, and histone deacetylase
inhibitors such
as BML-210 and compound 106.
[0714] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of various anti-oxidant compounds including,
but not
limited to, e.g., parenteral or oral administration of compositions comprising
glycyrrhizin, schisandra, ascorbic acid, L-glutathione, silyrnarin, lipoic
acid, and D-
alpha-tocopherol (see U.S. Pat. No. 7,078,064, incorporated expressly by
reference
for all purposes).
[0715] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of various anti-oxidant compounds including,
but not
limited to, e.g., parenteral or oral administration of compositions comprising
a water
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soluble Vitamin E preparation, mixed carotenoids, or selenium (see U.S. Pat.
No.
6,596,762, incorporated expressly by reference for all purposes).
[0716] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of parenteral or oral administration of
lecithin or
vitamin B complex (see U.S. Pat. Nos. 7,018,652; 6.180,139, incorporated
expressly
by reference for all purposes).
[0717] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of bile salt preparations including, but not
limited to,
e.g., ursodeoxycholic acid, chenodeoxycholic acid of other naturally occurring
or
synthetic bile acids or bile acid salts (see U.S. Pat. No. 6.297,229,
incorporated
expressly by reference for all purposes).
[0718] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a PPAR (peroxisome proliferator-activated
receptor) activity regulators (see U.S. Pat. No. 7,994,353, incorporated
expressly by
reference for all purposes).
[0719] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a benzothiazepine or benzothiepine
compound
represented by the following formula having a thioamide bond and a quaternary
ammonium substituent (see U.S. Pat. No. 7,973.030, incorporated expressly by
reference for all purposes).
[0720] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a mineralocorticoid receptor antagonist,
for
example, but not limited to, spironolactone and eplerenone.
[0721] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a beta-adrenergic antagonist (beta-
blocker), for
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CA 02881746 2015-02-13
example, but not limited to, metoprolol, bisoprolol, carvedilol, atenolol, and
nebivolol.
[0722] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a axacyclopentane derivative that inhibits
stearoyl-coenzyme alpha delta-9 desaturase (see U.S. Pat. No. 7,754,745,
incorporated expressly by reference for all purposes).
[0723] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a acylamide compound having secretagogue
or
inducer activity of adiponectin (see U.S. Pat. No. 7,732,637, incorporated
expressly
herein by reference for all purposes).
[0724] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of quaternary ammonium compounds (see U.S.
Pat.
No. 7,312,208, incorporated expressly by reference for all purposes).
[0725] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of an isoflavone compound (see U.S. Pat. No.
6,592,910, incorporated expressly by reference for all purposes).
[0726] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a macrolide antibiotic (see U.S. Pat. No.
5,760,010, incorporated expressly by reference for all purposes).
[0727] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of carnitine.
[0728] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a statin, for example, but not limited to,
HMG-
CoA reductase inhibitors such as atorvastatin and simvastatin.
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CA 02881746 2015-02-13
[0729] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of an N-acetyl cysteine.
[0730] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of another galectin inhibitor that may
inhibit a single
galectin protein or multiple galectin proteins, including, but not limited to,
e.g., small
organic inhibitors of galectin, monoclonal antibodies, RNA inhibitors, or
protein
inhibitors.
[0731] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a monoclonal antibody to inhibit lysyl
oxidase or
monoclonal antibody that binds to connective tissue growth factor.
[0732] In another embodiment, mitochondrial fission inhibitor peptides of the
present technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of pentraxin proteins, including, but not
limited to,
e.g., recombinant pentraxin-2.
[0733] In another embodiment, mitochondrial fission inhibitor peptides of the
present technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of an angiotensin receptor blocker (ARB) or
an
angiotensin-converting enzyme (ACE) inhibitor.
[0734] In another embodiment, mitochondrial fission inhibitor peptides of the
present technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a cGMP activating compound.
[0735] In another embodiment, mitochondrial fission inhibitor peptides of the
present technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a calcium channel blocker, for example,
but not
limited to, verapamil.
[0736] In another embodiment, mitochondrial fission inhibitor peptides of the
present technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a phosphodiesterase 5 inhibitor, for
example, but
not limited to, sildenafil, tadalafil, or vardenafil.
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CA 02881746 2015-02-13
[0737] In some embodiments mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with a
therapeutically effective amount of a diuretic.
[0738] In some embodiments, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with one or
more
additional agents selected from the group consisting of diuretics, ACE
inhibitors,
digoxin (also called digitalis), calcium channel blockers, and beta-blockers.
In some
embodiments, thiazide diuretics, such as hydrochlorothiazide at 25-50 mg/day
or
chlorothiazide at 250-500 mg/day, can be used. However, supplemental potassium
chloride may be needed, since chronic diuresis causes hypokalemis alkalosis.
Typical
doses of ACE inhibitors include captopril at 25-50 mg/day and quinapril at 10
mg/day.
[0739] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with an
adrenergic
beta-2 agonist. An "adrenergic beta-2 agonist" refers to adrenergic beta-2
agonists
and analogues and derivatives thereof, including, for example, natural or
synthetic
functional variants which have adrenergic beta-2 agonist biological activity,
as well as
fragments of an adrenergic beta-2 agonist having adrenergic beta-2 agonist
biological
activity. The term "adrenergic beta-2 agonist biological activity" refers to
activity
that mimics the effects of adrenaline and noradrenaline in a subject and which
improves myocardial contractility in a patient having heart failure. Commonly
known
adrenergic beta-2 agonists include, but are not limited to, e.g., clenbuterol,
albuterol,
fonneoterol, levalbuterol, metaproterenol, pirbuterol, salmeterol, and
terbutaline.
[0740] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) can be used in combination with an
adrenergic
beta-1 antagonist. Adrenergic beta-1 antagonists and adrenergic beta-1
blockers refer
to adrenergic beta-1 antagonists and analogues and derivatives thereof,
including, for
example, natural or synthetic functional variants which have adrenergic beta-1
antagonist biological activity, as well as fragments of an adrenergic beta-1
antagonist
having adrenergic beta-1 antagonist biological activity. Adrenergic beta-1
antagonist
biological activity refers to activity that blocks the effects of adrenaline
on beta
receptors. Commonly known adrenergic beta-1 antagonists include, but are not
limited to, acebutolol, atenolol, betaxolol, bisoprolol, esmolol, and
metoprolol.
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CA 02881746 2015-02-13
[0741] Clenbuterol, for example, is available under numerous brand names
including Spiropente (Boehinger Ingelheim), Broncodile (Von Boch I),
Broncoterolt (Quimedical PT), Cesbron (Fidelis PT), and Clenbuter0 (Biomedica
Foscama). Similarly, methods of preparing adrenergic beta-1 antagonists such
as
metoprolol and their analogues and derivatives are well-known in the art.
Metoprolol,
in particular, is commercially available under the brand names Lopressor
(metoprolol tartate) manufactured by Novartis Pharmaceuticals Corporation, One
Health Plaza, East Hanover, N.J. 07936-1080. Generic versions of Lopressor
are
also available from Mylan Laboratories Inc., 1500 Corporate Drive, Suite 400,
Canonsburg, Pa. 15317; and Watson Pharmaceuticals, Inc., 360 Mt. Kemble Ave.
Morristown, N.J. 07962. Metoprolol is also commercially available under the
brand
name Toprol XL , manufactured by Astra Zeneca, LP.
[0742] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) may be combined with one or more
additional
therapies for the prevention or treatment of porphyria. Treatment for acute
attacks of
hepatic porphyria typically comprise, but are not limited to, the use of
narcotic
analgesics (e.g., for abdominal pain), phenothiazines (e.g., for nausea,
vomiting,
anxiety, and restlessness), chloral hydrate (e.g., for insomnia), short-acting
benzodiazepines (e.g., for insomnia), carbohydrate loading, intravenous hemin
(e.g.,
lyophilized hematin, heme albumin, and heme arginate), allogenic liver
transplantation, and liver-directed gene therapy. Treatment for porphyria
cutanea
tarda typically comprises, but is not limited to, discontinuing risk factors
(e.g.,
alcohol, estrogens, iron supplements), phlebotomy, and low-dose regimens of
chloroquine or hydroxychloroquine. Treatment for erythropoietic cutaneous
porphyrias typically comprise, but is not limited to, chronic transfusions
(e.g., for
anemia), protection from sunlight, treatment of complicating bacterial
infections, and
bone marrow and cord blood transplantation. Treatment for EPP and XLP
typically
comprise, but is not limited to, sunlight avoidance, oral 0-carotene,
administration of
an a-melanocyte stimulating hormone analogue, administration of cholestyramine
and
other porphyrin absorbents (e.g., activated charcoal), plasmapheresis,
intravenous
hemin, and liver transplantation.
[0743] In some embodiments, the mitochondrial fission inhibitor peptide of the
present technology (e.g., P110 and/or P110*) is administered in combination
with one
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or more narcotic analgesics, phenothiazines, chloral hydrate, benzodiazepines,
hemin,
chloroquine, hydroxychloroquine, 0-carotene, a-melanocyte stimulating hormone,
cholestyramine, or activated charcoal, such that a synergistic effect in the
prevention
or treatment of porphyria results.
[0744] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) may be combined with one or more
additional
therapies for the prevention or treatment of Alport Syndrome. Treatment for
Alport
Syndrome typically comprises, but are not limited to, the use of ACE
inhibitors,
ARBs, HMG-CoA reductase inhibitors, aldosterone inhibitors, aliskiren,
calcineurin
inhibitors (e.g., cyclosporine A, tacrolimus), endothelin receptor antagonists
(e.g.,
sitaxentan, ambrisentan (LETAIRIS), atrasentan, BQ-123, zibotentan, bosentan
(TRACLEER), macitentan, tezosentan, BQ-788 and A192621), sulodexide,
vasopeptidase inhibitors (e.g., AVE7688), anti-transforming growth factor-01
antibody, chemokine receptor 1 blockers, bone morphogenetic protein-7, PPARy
agonists (e.g., rosiglitazone, pioglitazone, MRL24, Fmoc-L -Leu, SR1664,
SR1824,
GW0072, MCC555, CLX-0921, PAT5A, L-764406, nTZDpa, CDDO (2-cyano-3,12-
dioxooleana-1,9-dien-28-oic acid), ragaglitazar, 0-arylmandelic acids, and
NSAIDs)
and BAY-12-9566.
[0745] In some embodiments, the ACE inhibitors are selected from the group
consisting of captopril, alacepril, lisinopril, imidapril, quinapril,
temocapril, delapril,
benazepril, cilazapril, trandolapril, enalapril, ceronapril, fosinopril,
imadapril,
mobertpril, perindopril, ramipril, spirapril, randolapril and pharmaceutically
acceptable salts of such compounds.
[0746] In some embodiments, the ARBs are selected from the group consisting of
losartan, candesartan, valsartan, eprosartan, telmisartan, and irbesartan.
[0747] In some embodiments, the HMG-CoA reductase inhibitors (or statins) are
selected from the group consisting of lovastatin (e.g., ADVICOR (niacin
extended-
release/lovastatin) (AbbVie Pharmaceuticals, Chicago, Illinois), ALTOPREVTm
(lovastatin extended-release) (Shiongi, Inc., Atlanta, GA), MEVACOR (Merck,
Whitehouse Station, NJ), atorvastatin (e.g., CADUET (amlodipine and
atorvastatin)
(Pfizer, Morrisville, PA), LIPITOR (Pfizer, Morrisville, PA)), rosuvastatin
and/or
rosuvastatin calcium (e.g., CRESTOR (AstraZeneca, London, England)),
simvastatin
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CA 02881746 2015-02-13
(e.g., JUVISYNC (sitagliptin/simvastatin) (Merck, Whitehouse Station, NJ)),
SIMCOR (niacin extended-release/simvastatin) (AbbVie Pharmaceuticals,
Chicago,
Illinois), VYTORIN (ezetimibe/simvastatin) (Merck, Whitehouse Station, NJ),
and
ZOCOR (Merck, Whitehouse Station, NJ)), fluvastatin and/or fluvastatin sodium
(e.g., LESCOL , LESCOL XL (fluvastatin extended-release) (Mylan
Pharmaceuticals, Morgantown, WV)), pitavastatin (e.g., LIVALO (Kowa
Pharmaceuticals, Montgomery, AL)), pravastatin and pravastatin sodium (e.g.,
PRAVACHOL (Bristol-Myers Squibb, New York, NY)).
[0748] In some embodiments, the aldosterone inhibitors are selected from the
group
consisting of spironolactone (Aldactone0), eplerenone (Inspra0),
canrenone (canrenoate potassium), prorenone (prorenoate potassium), and
mexrenone (mexrenoate potassium).
[0749] In some embodiments, the mitochondrial fission inhibitor peptide of the
present technology (e.g., P110 and/or P110*) is administered in combination
with one
or more ACE inhibitors, ARBs, HMG-CoA reductase inhibitors, aldosterone
inhibitors, aliskiren, calcineurin inhibitors (e.g., cyclosporine A,
tacrolimus),
endothelin receptor antagonists (e.g., sitaxentan, ambrisentan (LETAIRIS),
atrasentan, BQ-123, zibotentan, bosentan (TRACLEER), macitentan, tezosentan,
BQ-
788 and A192621), sulodexide, vasopeptidase inhibitors (e.g., AVE7688), anti-
transforming growth factor-131 antibody, chemokine receptor 1 blockers, bone
morphogenetic protein-7, PPARy agonists (e.g., rosiglitazone, pioglitazone,
MRL24,
Fmoc-L -Leu, SR1664, SR1824, GW0072, MCC555, CLX-0921, PAT5A, L-764406,
nTZDpa, CDDO (2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid), ragaglitazar, 0-
arylmandelic acids, and NSAIDs) and/or BAY-12-9566, such that a synergistic
effect
in the prevention or treatment of Alport Syndrome results.
[0750] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) may be combined with one or more
additional
therapies for the prevention or treatment of vitiligo. Treatment for vitiligo
typically
comprises, but is not limited to, the use of topical steroid creams,
monobenzone,
antibiotics, vitamins, hormones, immunomodulators, dermatologic drugs, or
administering psoralen photochemotherapy. In some embodiments, the
mitochondrial
fission inhibitor peptide of the present technology (e.g., P110 and/or P110*)
is
administered in combination with one or more topical steroid creams,
monobenzone,
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antibiotics, vitamins, hormones, immunomodulators, dermatologic drugs,
psoralen
photochemotherapy, such that a synergistic effect in the prevention or
treatment of
vitiligo results.
[0751] In one embodiment, mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) may be combined with one or more
additional
therapies for the prevention or treatment of IPF. Additional therapies
include, but are
not limited to, oral corticosteroids, azathioprine, N-acetylcysteine, soluble
human
TNF receptor, interferon-ylb therapy, endothelin receptor antagonists,
phosphodiesterase inhibitors, tyrosine kinase inhibitors, antifibrotic agents,
colchicine, and anticoagulants.
EXAMPLES
[0752] The present technology is further illustrated by the following
examples,
which should not be construed as limiting in any way.
Example 1 ¨ Use of Mitochondrial Fission Inhibitor Peptides in the Treatment
of
Porphyria
[0753] This Example demonstrates the use of mitochondria' fission inhibitor
peptides, or derivatives, analogues or pharmaceutically acceptable salts
thereof (e.g.,
P110 and/or P110*), in the treatment of porphyria.
[0754] Subjects suspected of having or diagnosed as having porphyria receive
daily
administrations of a therapeutically effective amount of mitochondrial fission
inhibitor peptides, or derivatives, analogues or pharmaceutically acceptable
salts
thereof (e.g., P110 and/or P110*), alone or in combination with one or more
additional agents for the treatment or prevention of porphyria. Mitochondrial
fission
inhibitor peptides of the present technology (e.g., P110 and/or P110*) and/or
additional agents are administered orally, intranasally, intrathecally,
intraocularly,
intradermally, transmucosally, iontophoretically, topically, systemically,
intravenously, subcutaneously, intraperitoneally, or intramuscularly according
to
methods known in the art. Subjects will be evaluated weekly for the presence
and/or
severity of signs and symptoms associated with porphyria, including, but not
limited
to, e.g., cutaneous lesions, blistering skin lesions, hypertrichosis,
hyperpigmentation,
thickening and/or scarring of the skin, friability of the skin,
photosensitivity of the
skin, lichenification, leathery pseudovesicles, labial grooving, nail changes,
life
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threatening acute neurological attacks, abdominal pain and cramping,
constipation,
diarrhea, increased bowel sounds, decreased bowel sounds, nausea, vomiting,
tachycardia, hypertension, headache, mental symptoms, extremity pain, neck
pain,
chest pain, muscle weakness, sensory loss, tremors, sweating, dysuria, and
bladder
distension. Treatments are maintained until such a time as one or more signs
or
symptoms of porphyria are ameliorated or eliminated.
[0755] It is predicted that subjects suspected of having or diagnosed as
having
porphyria and receiving therapeutically effective amounts of mitochondrial
fission
inhibitor peptides, or derivatives, analogues or pharmaceutically acceptable
salts
thereof (e.g., P110 and/or P110*), will display reduced severity or
elimination of one
or more symptoms associated with porphyria. It is further expected that
administration of mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) in
combination with one or more additional agents will have synergistic effects
in this
regard.
[0756] These results will show that mitochondrial fission inhibitor peptides,
or
derivatives, analogues or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*), are useful in the treatment of porphyria. Accordingly, the
mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) are useful in methods
comprising
administering mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) to a
subject in need thereof for the treatment of porphyria.
Example 2 ¨ Use of Mitochondrial Fission Inhibitor Peptides in the Prevention
of
Porphyria
[0757] This Example demonstrates the use of mitochondrial fission inhibitor
peptides, or derivatives, analogues or pharmaceutically acceptable salts
thereof (e.g.,
P110 and/or P110*), in the prevention of porphyria.
[0758] Subjects at risk of having porphyria receive daily administrations of a
therapeutically effective amount of mitochondrial fission inhibitor peptides,
or
derivatives, analogues or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*), alone or in combination with one or more additional agents for the
treatment
or prevention of porphyria. Mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) and/or additional agents are administered
orally,
intranasally, intrathecally, intraocularly, intradermally, transmucosally,
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iontophoretically, topically, systemically, intravenously, subcutaneously,
intraperitoneally, or intramuscularly according to methods known in the art.
Subjects
will be evaluated weekly for the presence and/or severity of signs and
symptoms
associated with porphyria, including, but not limited to, e.g., cutaneous
lesions,
blistering skin lesions, hypertrichosis, hyperpigmentation, thickening and/or
scarring
of the skin, friability of the skin, photosensitivity of the skin,
lichenification, leathery
pseudovesicles, labial grooving, nail changes, life threatening acute
neurological
attacks, abdominal pain and cramping, constipation, diarrhea, increased bowel
sounds,
decreased bowel sounds, nausea, vomiting, tachycardia, hypertension, headache,
mental symptoms, extremity pain, neck pain, chest pain, muscle weakness,
sensory
loss, tremors, sweating, dysuria, and bladder distension.
[0759] It is predicted that subjects at risk of having or diagnosed as having
porphyria and receiving therapeutically effective amounts of mitochondrial
fission
inhibitor peptides, or derivatives, analogues or pharmaceutically acceptable
salts
thereof (e.g., P110 and/or P110*), will display delayed onset of porphyria, or
prevention of onset of porphyria. It is further expected that administration
of
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) in
combination
with one or more additional agents will have synergistic effects in this
regard.
[0760] These results will show that mitochondrial fission inhibitor peptides,
or
derivatives, analogues or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*), are useful in the prevention of porphyria. Accordingly, the
mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) are useful in methods
comprising
administering mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) to a
subject in need thereof for the prevention of porphyria.
Example 3 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Treating IPF
[0761] TGF-01-adenovirus induced lung fibrosis: TGF-01 adenovirus (Ad-TGF-
01) or control virus (Ad-DL) is prepared and treated as previously described
in Sime
et at., J Clin Invest 100:768-776 (1997). Ad-TGF-01 refers to porcine TGF-131
adenovirus (Ad-TGF131223/225), an adenovirus construct containing a mutation
of
cysteine to serine at positions 223 and 225, rendering the expressed TGF-01
biologically active. This virus expresses active TGF-01 in the lung over a
period of 7
to 14 days and produces extensive and progressive fibrosis in rats and mice.
C57/B6
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mice will receive 2 x 108 PFU virus in 50 itL sterile saline intratracheally
and will be
treated with saline; or a mitochondrial fission inhibitor peptide (e.g., P110
and/or
P110*). Mice are culled 5 or 14 days post instillation.
[07621 Determination of lung fibrosis and inflammation: Collagen content in
the left
lung is determined by sircol assay as per manufacturer's instructions.
Histological
lung inflammation and fibrosis score is carried out in Masson's trichrome
stained
sections.
[0763] Isolation of murine primary lung fibroblasts and primary type II
alveolar
epithelial cells: Primary cultures of lung fibroblasts are isolated by
collagenase
digestion (0.5 mg/ml for 1 hour at 37 C) of minced lungs and digests passed
through a
100-Arn cell strainer. Cells are cultured in DMEM containing 10% FCS for 4
days
until confluent. Lung fibroblasts are used at passage 2. Lung alveolar
epithelial cells
(AECs) are extracted following the method originally described by Corti et
al., Am J
Respir Cell Mol Rio! 14:309-315 (1996). Immunofluorescence is carried out
using
the following primary antibodies: mouse monoclonal anti-a-SMA clone 1A4
(Sigma,
Poole, UK), rabbit anti-mouse collagen 1 and mouse anti-active (ABC) 0-catenin
(Millipore).
[07641 Results: It is expected that intratracheal administration of adenoviral
TGF-
01 (Ad-TGF-01) in saline-treated mice will stimulate the formation of
fibroblast foci,
whereas mice treated with the Ad-DL control virus will not exhibit pulmonary
fibrosis. Additionally, AECs from saline-treated Ad-TGF-01 mice will show an
increase in a-SMA and collagen-1 expression levels compared to that observed
in
AECs isolated from Ad-DL infected mice. It is also anticipated that Ad-TGF- 01
mice treated with the mitochondrial fission inhibitor peptides (e.g., P110
and/or
P110*) will show a decrease in lung fibrosis and/or reduced collagen-1 and a-
SMA
levels compared to Ad-TGF-01 mice treated with saline only.
[0765] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful in treating IPF in
mammalian
subjects.
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Example 4 ¨ Use of Mitochondrial Fission Inhibitor Peptides to Reduce Tumor
Growth
[0766] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) to reduce the
growth rate
of implanted tumors.
[0767] A standard panel of 12 tumor cell lines will be used for the hollow
fiber
screening of the mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*).
These include NCI-H23, NCI-H522, MDA-MB-231, MDA-MB-435, SW-620, COLO
205, LOX, UACC-62, OVCAR-3, OVCAR-5, U251 and SF-295. The cell lines are
cultivated in RPMI-1640 containing 10% FBS and 2 mM glutamine. On the day
preceding hollow fiber preparation, the cells are given a supplementation of
fresh
medium to maintain log phase growth. For fiber preparation, the cells are
harvested
by standard trypsinization technique and resuspended at the desired cell
density (2-10
x 106 cells/mL). The cell suspension is then flushed into 1 mm (internal
diameter)
polyvinylidene fluoride hollow fibers with a molecular weight exclusion of
500,000
Da. The hollow fibers are heat-sealed at 2 cm intervals and the samples
generated
from these seals are placed into tissue culture medium and incubated at 37 in
5% CO2
for 24-48 hours prior to implantation. A total of 3 different tumor lines are
prepared
for each experiment so that each mouse receives 3 intraperitoneal implants (1
of each
tumor line) and 3 subcutaneous implants (1 of each tumor line). On the day of
implantation, samples of each tumor cell line preparation are quantitated for
viable
cell mass by a stable endpoint MTT assay so that the time zero cell mass is
known.
Mice are treated with vehicle or mitochondrial fission inhibitor peptides
(e.g., P110
and/or P110*) starting on day 3 or 4 following fiber implantation and
continuing daily
for 4 days. Control animals receive the tumor implants and are treated with
only the
empty vehicle. The therapeutic compositions are administered by
intraperitoneal
injection at 2 dose levels. The doses are based on the maximum tolerated dose
(MTD) determined during prior toxicity testing. The fibers are collected from
the
mice on the day following the fourth compound treatment and subjected to the
stable
endpoint MTT assay. The optical density of each implanted tumor sample is
determined spectrophotometrically at 540 nm and the mean of each treatment
group is
calculated. The percent net growth for each cell line in each treatment group
is
calculated and compared to the percent net growth in the vehicle treated
controls. A
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50% or greater reduction in percent net growth in the treated samples compared
to the
vehicle control samples is considered a positive result. Each positive result
is given a
score of 2 and all of the scores are totaled for a given mitochondrial fission
inhibitor
peptide (e.g., P110 and/or P110*). The maximum possible score for an agent is
96
(12 cell lines X 2 sites X 2 dose levels X 2 [score]). A compound is
considered for
xenograft testing if it has a combined ip + sc score of 20 or greater, a sc
score of 8 or
greater, or produces cell kill of any cell line at either dose level
evaluated.
[0768] Results: It is expected that vehicle treated controls will show an
increase in
tumor net growth after 4 days. It is also anticipated that treatment with the
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) will result
in
significantly reduced tumor net growth compared to vehicle treated controls.
[0769] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
reducing
tumor growth in mammalian subjects. The results will show that the
mitochondrial
fission inhibitor peptides of the present technology (e.g., P110 and/or P110*)
are
generally useful in treating a neoplastic disease.
Example 5 ¨ Mitochondrial Fission Inhibitor Peptides Inhibit HUVEC Cell
Migration
[07701 Chemotaxis is an integral part of angiogenesis, and this Example
demonstrates the effect of mitochondrial fission inhibitor peptides of the
present
technology (e.g., P110 and/or P110*) in inhibiting angiogenesis.
10771] In the first portion of the experimental series, the effect of the
chemoattractant vascular endothelial growth factor (VEGF) on human umbilical
vein
endothelial cells (HUVEC) is quantified. The experiment is carried out in a
transwell
plate, and in preparation therefor, HUVEC cells are grown to approximately 80%
confluency. The cells are suspended in basal media and placed in a transwell
plate on
fibronectin coated membrane inserts at 50,000 cells per insert. Varying
concentrations of VEGF are added to the bottom chamber of the transwell plate,
and
the plates are incubated for 4 hours at 37 C with a 5% CO2 atmosphere.
Following
incubation, the membranes are fixed and stained. Nonmigrated cells are removed
by
mechanical abrasion and cells that migrate through the membrane are counted.
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[0772] It is anticipated that VEGF will act as a chemotactic agent that
induces cell
migration, a process that is crucial to angiogenesis. Specifically, it is
expected that
certain VEGF concentrations will produce a strong chemotactic effect.
[0773] In the second portion of the experiment, the effect of mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*) in moderating chemotaxis, and
hence
angiogenesis, will be evaluated.
[0774] In this experimental series, HUVEC cells are incubated in a transwell
plate
with 30 ng/ml VEGF, and varying concentrations of the mitochondrial fission
inhibitor peptides (e.g., P110 and/or P110*), under experimental conditions as
described above. Group A cells will be incubated with VEGF only (positive
control);
Group B cells will be incubated with VEGF and a mitochondrial fission
inhibitor
peptide (e.g., P110 and/or P110*); Group C will be incubated with VEGF-
deficient
growth medium only (negative control).
[0775] It is anticipated that cells incubated with VEGF alone will show an
increase
in cell migration compared to cells incubated with VEGF-deficient growth
medium.
It is also anticipated that the cells treated with mitochondrial fission
inhibitor peptides
(e.g., P110 and/or P110*) will show a decrease in VEGF-mediated cell migration
compared to the Group A positive control cells.
[0776] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful as potent inhibitors
of the
angiogenic process, and as such will have utility in the treatment of diseases
in which
angiogenesis is a factor.
Example 6 ¨ Therapeutic Effect of Mitochondrial Fission Inhibitor Peptides on
4-
tertiary Butyl Phenol (4-TBP)-induced Cytotoxicity and Apoptosis in
Melanocytes
[0777] This Example will demonstrate the therapeutic effect of mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) on 4-TBP-induced
vitiligo.
[0778] Melanocytes are cultured and treated with 4-TBP to induce vitiligo
according to the procedures described in Yang & Boissy, Pigment Cell Research,
12:237-245 (1999). The experimental group of melanocytes is treated with 1-10
jig
of mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) after
exposure to
4-TBP. The control melanocyte group is exposed to 4-TBP only.
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CA 02881746 2015-02-13
[0779] It is anticipated that untreated melanocytes will exhibit high levels
of
cytotoxicity and apoptosis following exposure to 4-TBP (Vitiligo control)
compared
to melanocytes that are not exposed to 4-TBP (Normal). However, it is
anticipated
that melanocytes treated with mitochondrial fission inhibitor peptides (e.g.,
P110
and/or P110*) will show cell survival rates that are similar to normal
melanocytes that
are not exposed to 4-TBP and greater than untreated melanocytes following 4-
TBP
exposure.
[0780] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*), or pharmaceutically acceptable
salts
thereof, are useful in treating apoptosis and cytotoxicity associated with
chemically-
induced vitiligo. Accordingly, the mitochondrial fission inhibitor peptides of
the
present technology (e.g., P110 and/or P110*), are useful in treating, or
ameliorating
melanocyte degeneration and depigmentation observed in a subject suffering
from or
predisposed to vitiligo.
Example 7 ¨ Use of Mitochondrial Fission Inhibitor Peptides in the Treatment
of
Alport Syndrome in Humans
[0781] This Example demonstrates the use of mitochondrial fission inhibitor
peptides, or derivatives, analogues or pharmaceutically acceptable salts
thereof (e.g.,
P110 and/or P110*), in the treatment of Alport Syndrome.
[0782] Subjects suspected of having or diagnosed as having Alport Syndrome
receive daily administrations of 1%, 5% or 10% solution of a mitochondrial
fission
inhibitor peptide, or derivative, analogue or pharmaceutically acceptable salt
thereof
(e.g., P110 and/or P110*), alone or in combination with one or more additional
agents
for the treatment or prevention of Alport Syndrome. Mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) and/or additional
agents
are administered orally, intranasally, intrathecally, intraocularly,
intradermally,
transmucosally, iontophoretically, topically, systemically, intravenously,
subcutaneously, intraperitoneally, or intramuscularly according to methods
known in
the art. Subjects will be evaluated weekly for the presence and/or severity of
signs
and symptoms associated with Alport Syndrome, including, but not limited to,
e.g.,
hematuria, proteinuria, cylindruria, leukocyturia, hypertension, edema,
microalbuminuria, declining glomerular filtration rate, fibrosis, Glomerular
Basement
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Membrane (GBM) ultrastructural abnormalities, nephrotic syndrome,
glomerulonephritis, end-stage kidney disease, chronic anemia,
macrothrombocytopenia, osteodystrophy, sensorineural deafness, anterior
lenticonus,
dot-and-fleck retinopathy, posterior polymorphous corneal dystrophy, recurrent
corneal erosion, temporal macular thinning, cataracts, lacrimation,
photophobia,
vision loss, keratoconus, and leiomyomatosis. Treatments are maintained until
such a
time as one or more signs or symptoms of Alport Syndrome are ameliorated or
eliminated.
[0783] It is predicted that subjects suspected of having or diagnosed as
having
Alport Syndrome and receiving therapeutically effective amounts of
mitochondrial
fission inhibitor peptides, or derivatives, analogues or pharmaceutically
acceptable
salts thereof (e.g., P110 and/or P110*), will display reduced severity or
elimination of
one or more symptoms associated with Alport Syndrome. It is also expected that
Alport Syndrome subjects treated with the mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) will show normalization of one or more of ADAM8,
fibronectin, myosin 10, MMP-2, MMP-9, and podocin urine levels by at least 10%
compared to the untreated Alport Syndrome controls. It is further expected
that
administration of mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) in
combination with one or more additional agents will have synergistic effects
in this
regard compared to that observed in subjects treated with the mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*) or the additional agents alone.
[0784] These results will show that mitochondrial fission inhibitor peptides,
or
derivatives, analogues or pharmaceutically acceptable salts thereof (e.g.,
P110 and/or
P110*), are useful in the treatment of Alport Syndrome. These results will
show that
mitochondrial fission inhibitor peptides, or derivatives, analogues or
pharmaceutically
acceptable salts thereof (e.g., P110 and/or P110*), are useful in ameliorating
one or
more of the following symptoms: hematuria, proteinuria, cylindruria,
leukocyturia,
hypertension, edema, microalbuminuria, declining glomerular filtration rate,
fibrosis,
GBM ultrastructural abnormalities, nephrotic syndrome, glomerulonephritis, end-
stage kidney disease, chronic anemia, macrothrombocytopenia, osteodystrophy,
sensorineural deafness, anterior lenticonus, dot-and-fleck retinopathy,
posterior
polymorphous corneal dystrophy, recurrent corneal erosion, temporal macular
thinning, cataracts, lacrimation, photophobia, vision loss, keratoconus, and
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leiomyomatosis. Accordingly, the mitochondrial fission inhibitor peptides
(e.g., P110
and/or P110*) are useful in methods comprising administering mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*) to a subject in need thereof for
the
treatment of Alport Syndrome.
Example 8 ¨ Use of Mitochondrial Fission Inhibitor Peptides in the Prevention
of
Leber's Hereditary Optic Neuropathy (LHON) in a Mouse Model
[0785] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) in the prevention of Leber's Hereditary
Optic
Neuropathy in a mouse model.
[0786] Murine Model. This Example uses the murine model of LHON previously
described by Lin etal., Proc. Natl. Acad. Sci. 109(49):20065-20070 (2012). The
animals harbor an ND6 P25L mutation. The LT13 cell line corresponds to the ND6
P25L mutant fibroblast line used for mouse embryonic stem cell fusions.
[0787] Mice harboring the ND6 P25L mutation are administered 1-10 ps of
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*), or saline
vehicle
(control) subcutaneously once daily from 0-14 months of age. Various aspects
of
LHON are assessed in treatment and control animals at 14 and 24 months of age,
with
the ND6 P25L compared to wild-type mice for each parameter measured.
[0788] It is expected that administration of mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) once daily from 0-14 months of age will prevent the
onset
of, delay the onset of, and/or reduce the severity of the effects of the ND6
P25L
mutation, thereby preventing LHON in ND6 P25L mutant mice.
[0789] Reduced Retinal Response. The ND6 P25L mice are examined for ocular
function by electroretinogram beginning at 14 months of age. It is expected
that the
animals will show a significant deficit in nearly all parameters examined. The
scotopic B wave of dark-adapted ND6 P25L eyes is expected to be reduced in
amplitude by approximately 25.5% and approximately 33.1% with 0.01 and 1 cd=
s/m2
(maximum) stimulations. The scotopic A-wave of ND6 P25L mutant eyes is
expected to show approximately a 23% reduction. The scotopic oscillatory
potentials
(OPs), a high-frequency response derived from multiple retinal cell types, are
expected to show approximately a 20.7% and approximately a 21.7% reduction
with
0.01 and 1 cd= s/m2 stimulations. Photopic B-wave ERG amplitude, measuring
cone
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CA 02881746 2015-02-13
functions, is expected to be decreased approximately 17.7%. There is further
expected a trend toward increased latencies to the A and B waves. Despite the
functional deficit observed in the ERGs, it is expected that the ND6 P25L
mutants
will not exhibit reduced visual responses, as assessed by optokinetic
analysis.
[0790] It is expected that administration of mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) once daily from 0-14 months of age will prevent the
onset
of, delay the onset of, and/or reduce the severity of these effects of the ND6
P25L
mutation, thereby preventing these aspects of LHON in ND6 P25L mutant mice.
[0791] RGC Axonal Swelling and Preferential Loss of Smallest Fibers. Electron
microscopic analysis of RGC axons is expected to reveal that ND6 P25L mutants
exhibit axonal swelling in the optic nerve. The average axonal diameter is
expected
to be approximately 0.67 gm in wild-type and approximately 0.80 gm in ND6 P25L
mutant 14-month-old mice, and approximately 0.73 gm in wild-type and
approximately 0.85 gm in ND6 P25L mutant mice at 24 months of age. Fourteen-
month-old ND6 P25L mutant mice are expected to have an increased number of
large
fibers but fewer small axonal fibers (-0.5 gm). The change in axonal diameters
is
expected to be more pronounced in 24-month-old ND6 P25L mice. Hence, ND6
P25L mice are expected to have fewer small and medium axons (-0.8 gm) and more
swollen axonal fibers with diameters larger than 1 gm. This effect is expected
to be
the most severe in the area of the smallest fibers in the central and temporal
regions of
the mouse optic nerve, which corresponds to the human temporal region most
affected
in LHON.
[0792] Quantification of the number of axons in the optic nerves is expected
to
reveal no significant difference in the total counts at 14 months of age, and
approximately a 30% reduction at 24 months of age. Thus, the observed shift
toward
larger axons is predicted to be attributable initially (14 months) to swelling
of medium
axons, and later (24 months), to the loss of small axons.
[0793] It is expected that administration of mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) once daily from 0-14 months of age will prevent the
onset
of, delay the onset of, or reduce the severity of these effects in ND6 P25L
mutant
animals, thereby preventing these aspects of LHON.
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[0794] Abnormal Mitochondrial Morphology and Proliferation in RGC Axons.
Mitochondria in the optic tracts of the ND6 P25L mutants are expected to be
abnormal and increased in number, consistent with the compensatory
mitochondrial
proliferation observed in LHON patients. The optic tract axons of 14-month-old
ND6
P25L mice are expected to have approximately a 58% increase in mitochondria,
with
24-month-old animals having approximately a 94% increase. The ND6 P25L
mitochondria are expected to appear hollowed with irregular cristae, with
approximately 31.5% more of the ND6 P25L mitochondria being abnormal at 14
months and approximately 56% more at 24 months of age. Axons filled with
abnormal mitochondria are expected to demonstrate marked thinning of the
myelin
sheath.
[0795] It is expected that administration of mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) once daily from 0-14 months of age will prevent the
onset
of, delay the onset of, or reduce the severity of these effects in ND6 P25L
mutant
animals, thereby preventing these aspects of LHON.
[0796] Altered Liver Mitochondria Complex I Activity. The complex I activity
of
the ND6 P25L mice is assayed in liver mitochondria. Results are expected to
demonstrate that rotenone-sensitive NADH:ubiquinone oxidoreductase activity is
decreased by approximately 29%, which is equivalent to the reduction seen in
the
LT13 cell line. It is expected that the decrease in activity will not be
attributable to a
lower abundance of complex I, as it is expected that the NADH:ferricyanide
oxidoreductase will be unaltered in the ND6 mutant mice. It is further
expected that
the ND6 mutation will cause approximately a 25% decrease in mitochondrial
oxygen
consumption, also seen in the LT13 cell line.
[0797] It is expected that administration of mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*) once daily from 0-14 months of age will prevent the
onset
of, delay the onset of, or reduce the severity of these effects in ND6 P25L
mutant
animals, thereby preventing these aspects of LHON.
[0798] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*), are useful for preventing the
onset of,
delaying the onset of, and/or reducing the severity of the symptoms of LHON in
a
mammalian subject. As such, mitochondrial fission inhibitor peptides of the
present
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CA 02881746 2015-02-13
technology (e.g., P110 and/or P110*) are useful in methods for preventing LHON
in a
mammalian subject.
Example 9 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Treating
Friedreich's
Ataxia in in vitro Cell Culture
[0799] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) in the treatment
of
Friedreich's Ataxia in a cell culture model of the disease.
[0800] Cell line model. This Example uses human dermal fibroblasts derived
from
Friedreich's Ataxia patients previously described by Jauslin et al., Hum. Mol.
Genet.
11(24):3055 (2002).
[0801] Fibroblasts from Friedreich's Ataxia (FRDA) patients have been shown to
be
hypersensitive to L-buthionine-(S,R)-sulfoximine (BSO), a specific inhibitor
of GSH
synthetase. Jauslin et al., Hum. MoL Genet. 11(24):3055 (2002), Jauslin et
al.,
FASEB J. 17:1972-4 (2003), and International Patent Application WO
2004/003565.
The therapeutic efficacy of a compound can be assessed by assaying its ability
to
suppress BSO-mediated cell death in FRDA fibroblasts.
[0802] FRDA fibroblasts and fibroblasts from normal subjects are seeded in
microtiter plates at a density of 4000 cells per 100 1.11_, in growth medium
consisting of
25% (v/v) M199 EBS and 64% (v/v) MEM EBS without phenol red (Bioconcept,
Allschwil, Switzerland) supplemented with 10% (v/v) fetal calf serum (PAA
Laboratories, Linz, Austria), 100 U/mL penicillin, 100 ,g/mL streptomycin
(PAA
Laboratories, Linz, Austria), 10 1.1g/mL insulin (Sigma, Buchs, Switzerland),
10
ng/mL EGF (Sigma, Buchs, Switzerland), 10 ng/mL bFGF (PreproTech, Rocky Hill,
NJ, USA) and 2 mM glutamine (Sigma, Buchs, Switzerland).
[0803] The test samples are supplied in 1.5 ml glass vials. The mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) are diluted with DMSO,
ethanol
or PBS to result in a 5 mM stock solution. Once dissolved, they are stored at
¨20 C.
Reference antioxidants (Idebenone, decylubiquinone, a-tocopherol acetate and
trolox)
are dissolved in DMSO.
[0804] Test samples are screened according to the following protocol:
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[0805] A culture with FRDA fibroblasts is started from a 1 ml vial with
approximately 500,000 cells stored in liquid nitrogen. Cells are propagated in
10 cm
cell culture dishes by splitting every third day in a ratio of 1:3 until nine
plates are
available. Once confluent, fibroblasts are harvested. For 54 micro titer
plates (96
well-MTP) a total of 14.3 million cells (passage eight) are re-suspended in
480 ml
medium, corresponding to 100 pi medium with 3,000 cells/well. The remaining
cells
are distributed in 10 cm cell culture plates (500,000 cells/plate) for
propagation. The
plates are incubated overnight at 37 C in an atmosphere with 95% humidity and
5%
CO2 to allow attachment of the cells to the culture plate.
[08061 MTP medium (243 Al) is added to a well of the microtiter plate. The
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) are thawed,
and 7.5
Al of a 5 mM stock solution is dissolved in the well containing 243 1 medium,
resulting in a 150 AM master solution. Serial dilutions from the master
solution are
made. The period between the single dilution steps is kept as short as
possible
(generally less than 1 second).
[0807] Plates are kept overnight in the cell culture incubator. The next day,
10 Al of
a 10 mM BSO solution is added to the wells, resulting in a 1 mM final BSO
concentration. Forty-eight hours later, three plates are examined under a
phase-
contrast microscope to verify that the cells in the 0% control (wells El-H1)
are clearly
dead. The medium from all plates is discarded, and the remaining liquid is
removed
by gently tapping the plate inversed onto a paper towel.
[0808] 100 Al of PBS containing 1.2 AM Calcein AM is then added to each well.
The plates are incubated for 50-70 minutes at room temperature. Then, the PBS
is
discarded, and the plate is gently tapped on a paper towel. Fluorescence
intensity is
measured with a Gemini Spectramax XS spectrofluorimeter (Molecular Devices,
Sunnyvale, CA, USA) using excitation and emission wavelengths of 485 and 525
nm,
respectively.
[0809] It is anticipated that untreated FRDA cells will exhibit high levels of
cell
death following exposure to BSO (FRDA Control) as compared to fibroblasts
derived
from normal subjects (Normal). However, it is anticipated that FRDA
fibroblasts
treated with mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) will
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show cell survival rates that are similar to normal subjects and greater than
untreated
FRDA fibroblasts, following BSO exposure.
[0810] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful in the treatment of
Friedreich's Ataxia.
Example 10 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Treating
Mitochondrial Iron Loading in Friedreich's Ataxia Mouse Model
[0811] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) in treating
mitochondrial
iron loading in a mouse model of Friedreich's Ataxia.
[0812] Mouse model. This Example uses the muscle creatine kinase (MCK)
conditional frataxin knockout mice described by Puccio et al., Nat. Genet.
27:181-186
(2001). In this model, the tissue-specific Cre transgene under the control of
MCK
promoter results in the conditional deletion of frataxin in only the heart and
skeletal
muscle.
[0813] 8-week-old mutant mice are administered a daily dose of 0.25 mg/kg/day
of
the mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*), or
saline
vehicle only (control) subcutaneously for two weeks. Total RNA is isolated
from
hearts of two 10-week-old wild-type mice, two 10-week-old untreated mutant
mice
and two 10-week-old treated mutant mice. Total RNA is isolated using TRIzol
(Invitrogen). First-strand cDNA synthesis and biotin-labeled cRNA are
performed
and hybridized to the mouse Affymetrix GeneChip 430 2Ø A 2-phase strategy is
used to identify differentially expressed genes. First, genome-wide screening
is
performed using Affymetrix GeneChips. Then, low-level analysis is performed
with
Affymetrix GeneChip Operating Software 1.3.0, followed by the GC robust
multiarray average (GCRMA) method for background correction and quantile¨
quantile normalization of expression. Tukey's method for multiple pairwise
comparisons is applied to acquire fold-change estimations. Tests for
significance are
calculated and adjusted for multiple comparisons by controlling the false
discovery
rate at 5%.
[0814] Definitive evidence of differential expression is obtained from RT-PCR
assessment of samples used for the microarray analysis and at least 3 other
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independent samples. Principal component analysis is performed by standard
methods. Western blot analysis is performed using antibodies against frataxin
(US
Biological); Tfrl (Invitrogen); Fpnl (D. Haile, University of Texas Health
Science
Center); Hmox 1 (AssayDesig,ns); Sdha, Gapdh, and Iscul/2 (Santa Cruz
Biotechnology); Fech (H. Dailey, University of Georgia, Biomedical and Health
Sciences Institute); Hfe2 (S. Parkkila, University of Tampere, Institute of
Medical
Technology); Nfsl, Uros, and Alad (Abnova); Sec1511 (N.C. Andrews, Duke
University); Ftll, Fthl, Ftmt (S. Levi, San Raffaele Institute); and Hifl ot
(BD
Biosciences).
[0815] For heme assays, hearts are exhaustively perfused and washed with PBS
(0.2% heparin at 37 C) to remove blood. After homogenization, heme is
quantified
using the QuantiChrom Heme Assay (BioAssay Systems). Tissue iron is measured
via inductively coupled plasma atomic emission spectrometry.
[0816] It is anticipated that untreated mutant mice will exhibit decreased
expression
of genes involved in heme synthesis, iron¨sulfur cluster assembly, and iron
storage
(FRDA Control) as compared to wild-type mice (Normal). However, it is
anticipated
that mutant mice treated with the mitochondrial fission inhibitor peptides
(e.g., P110
and/or P110*) will show expression levels that are similar to normal subjects
with
respect to genes involved in these three mitochondrial iron utilization
pathways.
[0817] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful in treating
mitochondrial iron
loading in a mammalian model of Friedreich's Ataxia.
Example 11 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Treating
Complex I
and ATP Content Deficiency in Patients Suffering from a Mitochondrial Disease
or
Disorder
[0818] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) in treating
complex I and
ATP content deficiency in patients suffering from a mitochondrial disease or
disorder.
[0819] Patients diagnosed with any mitochondrial disease or disorder described
herein are administered a daily dose of 0.5 mg/kg/day of the mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*); or saline vehicle (control) for
six weeks.
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[0820] Isolation of Lymphocytes from Peripheral Blood. Blood is diluted with
Hank's solution at a ratio of 1:2 within one hour of extraction and slowly
layered onto
a 15-mL screw-cap tube containing 5 mL Ficolymph (Bharafshan Co. Tehran,
Iran.).
The tubes are centrifuged for 20 minutes at 1000 x g, after which the
lymphocyte-
containing layer is collected into a new centrifuge tube using a sterile
pipette. The
lymphocyte mix is then diluted in 10 mL Hank's solution and centrifuged for 10
minutes at 440xg. The supernatant is discarded, 5 mL of Hank's solution is
added, the
pellet is mixed gently in this buffer, and the mixture is allowed to sit for
about 45
seconds (s). The mixture is gently pipetted and then centrifuged at 230xg for
15
minutes. The supernatant is discarded, and the pellet is suspended in RPMI
1640
medium (Bharashan Co. Tehran, Iran) supplemented with L-glutamine.
[0821] Complex I activity assay. Fresh lymphocyte pellets are homogenized by
sonication in 20 mmol/L potassium phosphate buffer (pH 7.5) for 15s (three
bursts of
5s each) at 30W on ice. The final protein concentration is quantified
according to
Bradford's method. The homogenate, containing 2-4 g/L protein, is kept on ice
and
used for assay the same day. Biochemical studies are carried out on lymphocyte
homogenate of 12 patients and 25 controls. NADH-ferricyanide reductase
activity is
also assayed spectrophotometrically by following the disappearance of oxidized
ferricyanide at 410 nm and 30 C. The assay mixture contained in 1 mL: NADH,
ferricyanide, triethanolamin and phosphate buffer (pH 7.8). The reaction is
started by
the addition of the lymphocyte homogenate.
[0822] Extraction and quantification of intracellular ATP. The lymphocyte
cells
are pelleted in a microcentrifuge tube by centrifugation at 12,000 g for 10
min. The
cellular ATP is then extracted by adding 0.5 mL water and boiling the cell
pellet for 5
min. After vortexing and centrifugation (12,000 g for 5 min at 4 C), 50 uL of
the
supernatant is used for bioluminescence measurement. The standard curve of ATP
is
obtained by serial dilutions of 4 mM ATP solution (0.25, 0.5, 1.0, 2.0, and
4.0). Light
emission is measured with a Sirius tube luminometer, Berthold defection system
(Germany). After calibration against the ATP standard, the ATP content of the
cell
extract is determined.
[0823] It is anticipated that lymphocytes derived from untreated subjects will
exhibit decreased complex I activity and reduced intracellular ATP levels
(mitochondrial disease Control) as compared to controls (Normal). However, it
is
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CA 02881746 2015-02-13
,
anticipated that subjects treated with the mitochondrial fission inhibitor
peptides (e.g.,
P110 and/or P110*) will show complex I activity and ATP levels that are
similar to
normal subjects and greater than untreated subjects suffering from a
mitochondrial
disease or disorder.
[0824] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful in treating complex I
and
ATP content deficiency in patients suffering from a mitochondrial disease or
disorder.
Example 12 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Restoring
Aconitase
Activity in Cultured Cells Following Deferiprone Exposure
[0825] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) in restoring
aconitase
activity in cultured cells that have been exposed to deferiprone.
[0826] Deferiprone has been shown to potently impair aconitase activity,
presumably through reduced iron-sulfur cluster biosynthesis. Goncalves et al.,
BMC
Neurology 8:20 (2008).
[0827] Fibroblasts derived from forearm biopsies taken from healthy controls
are
grown under standard conditions in Dulbecco's modified Eagle's medium (DMEM;
Gibco Invitrogen, Cergy Pontoise, France) supplemented with 10% fetal calf
serum,
mg/mL penicillin/streptomycin and 2 mM L-Glutamine (as GlutamaxTM; Gibco
Invitrogen). Final iron content in culture medium will amount to 2-3 M. The
medium (4 mL/25 cm2 flask; 3 mL/10 cm2 well) is changed every three days.
[0828] Fibroblasts are administered 1-10 jig of mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*), or empty vehicle (control) for 24 hours
before
addition of deferiprone. Fibroblasts are seeded at 18 x 103 cells/cm2.
Fibroblasts are
then treated with 75 AM deferiprone for 7 days. Aconitase measurement is
spectrophotometrically carried out by following aconitate production from
citrate at
240 nm on the supernatant (800 g x 5 min) of detergent-treated cells (0.2%
lauryl
maltoside). Protein concentration is measured according to Bradford method.
[0829] It is anticipated that untreated fibroblasts will exhibit reduced
aconitase
activity following exposure to deferiprone (Control) as compared to
fibroblasts that
are not exposed to deferiprone (Normal). However, it is anticipated that
concurrent
treatment with mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*) will
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CA 02881746 2015-02-13
show aconitase activity that is similar to normal subjects and greater than
untreated
fibroblasts following deferiprone exposure.
[0830] These results will show that mitochondrial fission inhibitor peptides
of the
present technology (e.g., P110 and/or P110*) are useful in restoring aconitase
activity
in cultured cells that have been exposed to deferiprone.
Example 13 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Reducing
Mitochondrial Fission
[0831] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) in the reduction
of
mitochondrial fission.
[0832] Cultured human SH-SY5Y neuronal cells are treated with buffer; 5 11M
CCCP (carbonyl cyanide m-chloro phenyl hydrazone, a mitochondrial uncoupler);
or
[tIVI CCCP and mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*);
for 30 minutes. The cells are then stained with anti-Tom20 antibody, a
mitochondrial
marker, and Hoechst stain. Mitochondrial morphology is analyzed using 63X oil
immersion lens.
[0833] Results ¨ It is expected that control cells treated with CCCP will show
extensive mitochondrial fragmentation as manifested by small, round or dot-
like
staining patterns. It is also anticipated that treatment with the
mitochondrial fission
inhibitor peptides (e.g., P110 and/or P110*) will result in significantly
reduced
mitochondrial fission compared to control cells that are only exposed to CCCP.
[0834] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
reducing
mitochondrial fission in mammalian subjects.
Example 14 ¨ Use of Mitochondrial Fission Inhibitor Peptides to Increase
Protein
Expression Levels of Fully Assembled Complex I and Complex II in Cells Bearing
Complex I Mutations
[0835] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) to restore
electron
transport chain function in complex I mutant cells.
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[0836] Experimental fibroblast cells are derived from patients with a mutation
in
different Complex I subunits. Control cells are human skin fibroblasts derived
from
healthy controls. Cultured Complex I mutant fibroblasts are incubated with
buffer or
a mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) for up to
72 hours.
The cells are then harvested by trypsinization and washed twice with ice-cold
PBS.
The cell suspensions are centrifuged for 5 minutes at 4 C and the cell
pellets are
snap-frozen in liquid nitrogen. The cell pellets are subsequently thawed on
ice and
resuspended in 100 tal of ice-cold PBS.
[0837] Isolation of OXPHOS complexes: The cell suspension is incubated with
100
L (4 mg/mL) digitonin (Sigma, Zwijndrecht, Netherlands) on ice for 10 min.
Digitonin dissociates membranes that contain cholesterol, thereby dissociating
the cell
membrane and the outer mitochondrial membrane, but not the inner mitochondria'
membrane. Next, 1 mL ice-cold PBS is added to dilute the digitonin, followed
by
centrifugation (10 mm; 15,600xg; 4 C). The resulting pellets contain a cell
fraction
which is enriched for mitoplasts. The supernatant is removed and the pellets
are
resuspended in 100 AL ice-cold PBS. 1 mL ice-cold PBS is then added and the
suspension is centrifuged again (5 min; 15,600 xg; 4 C), followed by removal
of the
supernatant and resuspension of the pellet in 100 AL ice-cold PBS. The
supernatant is
removed with a syringe and needle and the pellets containing the mitoplast
fraction
are stored overnight (-20 C).
[0838] The complexes of the OXPHOS system are extracted from the inner
membrane withi3-lauryl maltoside and aminocaproic acid. The pellets are thawed
on
ice and solubilized in 100 ttL ACBT buffer containing 1.5 M E-aminocaproic
acid
(Serva, Amsterdam, Netherlands) and 75 mM Bis-Tris/HC1 (pH 7.0) (Sigma).
Subsequently 10 L 20% (w/v) 0-lauryl maltoside (Sigma) is added and the
suspension is left on ice for 10 min. Next, the suspensions are centrifuged
(30 min;
15,600 xg; 4 C) and the supernatants which contain the isolated complexes are
transferred to a clean tube (L.G. Nijtmans et al., Methods 26 (4): 327-334
(2002)).
The protein concentration of the isolated OXPHOS complexes is determined using
a
Biorad Protein Assay (Biorad, Veenendaal, Netherlands). Blue-native PAGE
analysis
of mitoplasts is performed as described in L.G. Nijtmans et al., Methods 26
(4): 327-
334 (2002).
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[08391 Complex I or complex II protein detection: To visualize the amount of
complex I or complex II present in the BN-PAGE gels, the proteins are
transferred to
a PVDF membrane (Millipore, Amsterdam, Netherlands) using standard Western
blotting techniques and detected by immunostaining. After the blotting and
prior to
blocking the PVDF membrane with 1:1 PBS-diluted Odyssey blocking buffer (Li-
cor
Biosciences, Cambridge, UK), the PVDF blot is stripped with stripping buffer
for 15
mm at 60 C. The stripping buffer consists of PBS, 0.1% Tween-20 (Sigma) and 2%
SDS (Serva). A monoclonal primary antibody against NDUFA9 (39 kDa) (Molecular
probes, Leiden, The Netherlands) is used for detection of Complex I. To detect
Complex II, a monoclonal antibody against the 70 kDa subunit of complex II is
used
(Molecular probes). Both primary antibodies are diluted in PBS, 0.1% Tween-20
and
2.5% Protifar Plus (Nutricia, Cuijk, The Netherlands) and allowed to bind to
the
complex for 4 hours at room temperature or overnight at 4 C. The bound primary
antibodies are subsequently detected by IRDye 800 CW conjugated anti-Mouse
antibody (Li-cor Biosciences) at a final concentration of 0.1 p.g/mL.
[0840] Results: It is expected that untreated Complex I mutant cells will show
reduced protein expression levels of Complex I and Complex II compared to
untreated healthy control cells. It is also anticipated that treatment with
the
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) will result
in an
increase in fully assembled complex I and complex II protein levels in Complex
I
mutant cells.
[0841] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
elevating
Complex I and Complex II protein levels in mammalian subjects. The results
will
show that the mitochondrial fission inhibitor peptides of the present
technology (e.g.,
P110 and/or P110*) are useful in promoting electron transport chain function
generally.
Example 15 ¨ In vivo Effect of Mitochondrial Fission Inhibitor Peptides on
Grip
Strength in Ndufs4 Knockout Mice
[0842] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) to improve grip
strength
in Ndufs4 knockout (Complex I deficient) mice.
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[0843] Animals and Treatments: Ndufs4 knockout (KO) and wild-type (WT) mice
are generated by crossing Ndufs4 heterozygote males and females (Kruse SE, et
al.,
2008, Cell Metab 7:312-320). Animals are divided into the following groups:
vehicle-WT; vehicle-KO; or mitochondrial fission inhibitor peptides-KO.
Animals
are tested at 3, 5 and 6 weeks of age. Animals will receive either vehicle
(control)
injections, consisting of sterile water, or injections consisting of a
mitochondrial
fission inhibitor peptide (e.g., P110 and/or P110*). Animals are injected
twice a day.
Injections begin during week 3 of life, and are continued daily until the
conclusion of
the experiment in week 6.
[0844] Data Analysis: All data are expressed as mean + SEM. Data are analyzed
using a one way ANOVA in SPSS version 20Ø Significant overall effects (i.e.,
genotype, treatment and/or genotype treatment interaction) are further
analyzed using
Fisher's PLSD post-hoc analyses.
[0845] Grip Strength Paradigm: The grip strength test is designed to measure
muscular strength in rodents. The apparatus consists of a single bar, which
the animal
will grasp by instinct. Once the bar has been gasped, the experimenter gently
retracts
the animal until the animal is forced to release the bar. The amount of force
exerted
by the animal on the bar is measured in Pond (p) (1 p = 1 gram). The grip
strength
test is repeated 5 times and the average force exerted is used as the
quantitative
readout. All measurements will be corrected for body weight, using the
following
equation:
[0846] Grip Strength Score = ((week X trials 1 + 2 + 3 + 4 +5)/5)/ Average
Body
Weight week X (g) (Week X = week 3, 5 or 6)
[0847] Testing Procedure: On testing days, animals will receive their morning
injection 30 minutes prior to their testing time. After injections, the
animals will be
placed in the testing room for a 30 minute acclimation period.
[0848] Results: It is expected that vehicle KO animals will show remarkably
decreased grip strength compared to wild-type control animals. It is also
anticipated
that chronic treatment with the mitochondrial fission inhibitor peptides
(e.g., P110
and/or P110*) will result in significantly improved grip strength in the
knockout
animals compared to vehicle knockouts.
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[0849] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
improving
grip strength in mammalian subjects. The results will show that the
mitochondrial
fission inhibitor peptides of the present technology (e.g., P110 and/or P110*)
are
generally useful in treating neuromuscular defects in Complex I deficient
subjects.
Example 16 ¨ Mitochondrial Fission Inhibitor Peptides Restore Motor and
Cognitive
Function in an in vivo Huntington Disease (HD) Animal Model
[0850] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) to reduce the
neurological defects associated with HD.
[0851] R6/2 mice, expressing exon 1 of the human HD gene carrying more than
120
CAG repeats, exhibit progressive neurological phenotypes that mimic the
features of
HD in humans. The mice develop progressive neurological phenotypes gradually
with mild phenotype (e.g., resting tremor) as early as 5 weeks of age and
severe
symptoms (including reduced mobility and seizures) at 9-11 weeks, with many of
the
mice dying by 14 weeks.
[0852] R6/2 HD transgenic mice are treated with an empty vehicle or a
mitochondrial fission inhibitor peptide (e.g., P110 and/or P110*) using Alzet
osmotic
mini-pumps from age 5 weeks to 13 weeks. These animals will be subjected to a
number of behavioral assessments to study motor and cognitive function. Rotor-
rod
and mobility in an activity chamber are used for assessment of motor function,
and
the Y-maze is used for assessment of working memory.
[0853] Results ¨ It is anticipated that vehicle-treated R6/2 mice will display
major
motor deficits such as a reduced ability to stand on their rear limbs and
increased
periods of immobility compared to wild-type controls. It is further
anticipated that
treatment with the mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*)
will restore motor activity and improve cognitive function (as demonstrated by
the
animals' performance in the Y-maze test).
[0854] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
restoring
cognitive and motor function in mammals suffering from HD. The results will
show
that the mitochondrial fission inhibitor peptides of the present technology
(e.g., P110
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and/or P110*) are generally useful in treating symptoms associated with
neurodegenerative diseases.
Example 17 ¨ Use of Mitochondrial Fission Inhibitor Peptides to Suppress A13-
mediated Toxicity in the Brain
[0855] This Example will demonstrate use of the mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*) to treat or
ameliorate the
toxic effects of AO accumulation in brain tissue.
[0856] Rats are treated with saline or a mitochondrial fission inhibitor
peptide (e.g.,
P110 and/or P110*) (0.5-2 iznol/kg body weight, n=12). The compositions are
injected intraperitoneally into the animal 24 hours before hippocampal slices
are
obtained to measure long-term potentiation (LTP). Brain slices from each group
are
incubated with Ap fragments for 15 min before evaluating LTP.
[0857] Results ¨ It is expected that brain slices recovered from saline-
treated
controls will show impaired LTP post Ap treatment. It is also anticipated that
treatment with the mitochondrial fission inhibitor peptides (e.g., P110 and/or
P110*)
will suppress Ap-mediated impairment of LTP.
[0858] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
treating or
ameliorating Ap-mediated toxicity in brain tissue. The results will show that
the
mitochondrial fission inhibitor peptides of the present technology (e.g., P110
and/or
P110*) are generally useful in reducing the synaptic dysfunction and memory
loss
caused by AP accumulation generally.
Example 18 ¨ Use of Mitochondrial Fission Inhibitor Peptides to Delay Ageing
[0859] This Example will demonstrate use of the methods and compositions of
the
present technology to reduce the frequency and/or severity of age-related
symptoms.
The Example will demonstrate the use of mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) in delaying ageing.
[0860] Ercel-/' progeroid mice are treated with mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) (i.p. about 0.5-2 mg/kg) in sunflower oil
carrier
three times per week over an 18-21 week period. Control animals are Erce17
progeroid mice that receive sunflower seed oil according to the same schedule.
The
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treated and control mice are monitored twice a week for weight and
symptom/sign
development. Symptoms include dystonia, trembling, kyphosis, ataxia, wasting,
priapism, decreased activity, incontinence, and vision loss. The rate of
deterioration
of intervertebral discs (an index of degenerative disease of the vertebra) is
assessed by
measuring the level of glycosaminoglycan in the discs in treated and control
mice.
[0861] Results ¨ It is expected that treatment with the mitochondrial fission
inhibitor peptides (e.g., P110 and/or P110*) will result in a significant
delay in onset
of age-related degeneration compared to controls treated with vehicle only. It
is also
anticipated that the intervertebral discs of mice treated with the
mitochondrial fission
inhibitor peptides (e.g., P110 and/or P110*) will contain more
glycosaminoglycan
relative to control mice, indicating inhibition of disc degeneration.
[0862] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
reducing
the frequency and/or severity of age-related symptoms. The results will show
that the
methods and compositions described herein are useful in delaying ageing
generally.
Example 19 ¨ Use of Mitochondrial Fission Inhibitor Peptides to Treat
Mitochondrial
Dysfunction
[0863] This Example demonstrates the use of mitochondrial fission inhibitor
peptides, or derivatives, analogues or pharmaceutically acceptable salts
thereof (e.g.,
P110 and/or P110*), to treat different aspects of mitochondrial dysfunction.
[0864] Lymphocytes, fibroblasts or neurons are derived from subjects suspected
of
having or diagnosed as having a mitochondria' disease or disorder. The
isolated cells
are cultured using conventional methods that promote optimal growth of a given
cell
type. The resulting cell cultures are subjected to the following assays:
[0865] Mitochondrial Membrane Potential (zlipm) Assay: For the determination
of
Am, cells are pre-treated with or without mitochondrial fission inhibitor
peptides
(e.g., P110 and/or P110*). The cells are treated with 5 mM Dulbecco's modified
Eagle's minimal essential medium (DEM) for 120 minutes, collected by
centrifugation
at 300xg for 3 minutes and then washed twice with phosphate buffered saline.
The
cells are re-suspended in PBS buffer and incubated at 37 C in the dark for 15
minutes
with 250 nM TMRM (a cationic dye which accumulates within mitochondria in
accordance with the AwmNemst potential). Cells are collected by centrifugation
at
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300xg for 3 minutes and then washed twice with phosphate buffered saline. The
samples are analyzed immediately by flow cytometry using 488 nm excitation
laser
and the FL2-H channel. The protonophore FCCP (30 M) will be used to dissipate
the chemiosmotic proton gradient (4H+) and serves as a control for loss of
Atm.
The results obtained will be verified in three independent experiments.
[0866] Trypan Blue Cell Viability Assay: This technique is used to assess the
cytoprotective effects of mitochondrial fission inhibitor peptides (e.g., P110
and/or
P110*) in cultured cells pharmacologically treated to induce cell death by GSH
depletion. DEM is used to deplete cellular GSH and induce oxidative stress.
The
viability of DEM-treated cells is determined by their ability to exclude the
dye trypan
blue. Viable cells exclude trypan blue; whereas, non-viable cells take up the
dye and
stain blue. Briefly, cells are seeded at a density of 1 x106 cells/mL and
treated with
different concentrations of mitochondrial fission inhibitor peptides (e.g.,
P110 and/or
P110*). Cells are incubated at 37 C in a humidified atmosphere of 5% CO2 in
air for
three hours with 5 mM DEM. Cell viability is determined by staining cells with
0.4%
trypan blue using a hemocytometer. At least 500 cells are counted for each
experimental group.
[0867] Cytochrome c Reduction Assay: The rate of cytochrome c (10 ii,M)
reduction
is measured by monitoring the change in absorbance at 550 nm. Briefly the
reaction
is initiated by addition of 100 /LM of mitochondrial fission inhibitor
peptides (e.g.,
P110 and/or P110*) to a mixture containing 50 mM phosphate buffer, 0.1 mM
EDTA,
pH 7.8, and 10 AM cytochrome c (Sigma, St. Louis, Mo. USA). For cytochrome c
reduction by superoxide, xanthine oxidase (0.01 IU/mL) (Sigma, St. Louis, Mo.
USA)
is used in presence of xanthine (50 AM).
[0868] Total Cellular ATP Concentration Assay: The reductions of mitochondrial
respiratory chain activity in CoQ10 deficient patients have been reported
(Quinzii G
et al., FASEB J. 22:1874-1885 (2008)). Briefly, lymphocytes (2x105 cell/mL),
are
plated (1 mL in 12-well plates) and treated with mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) at final concentrations of 5, 10 ttM, and
25 tiM and
incubated at 37 C for 48 hours in a humidified atmosphere containing 5% CO2
in air.
Mitochondrial fission inhibitor peptides of the present technology (e.g., P110
and/or
P110*) are prepared by first making 20 mM stock solutions in DMSO. Cells are
transferred (100 L) to 96-well microtiter black-walled cell culture plates
(Costar,
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Corning, N.Y.). The total intracellular ATP level is measured in a luminator
(ClarityTM luminescence microplate reader) with the ATP Bioluminescence Assay
Kit
(ViaLight Plus ATP monitoring reagent kit, Lonza) following the
manufacturer's
instructions. The standard curve of ATP is obtained by serial dilution of 1 mM
ATP
solution. After calibration against the ATP standard, the ATP content of the
cell
extract is determined and normalized for protein content in the cell.
[0869] Mitochondrial Bioenergetics Assessment: The use of mitochondrial
fission
inhibitor peptides (e.g., P110 and/or P110*) and methylene blue analogues
(positive
control) to normalize and restore the respiratory chain activities in cultured
cells
derived from subjects with a mitochondrial disease or disorder are assessed.
Lymphocytes are cultured under glucose-free media supplemented with galactose
for
two weeks to force energy production predominantly through oxidative
phosphorylation rather than glycolysis. Lymphocytes are cultured in RPMI 1640
medium glucose-free supplemented with 25 mM galactose, 2 mM glutamine and 1%
penicillin-streptomycin, and 10%, dialyzed fetal bovine serum FBS (<0.5
fig/mL).
Briefly, lymphocytes (2x105 cell/mL), are plated (1 mL in 12-well plates) and
treated
with the mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*) at
final
concentrations of 50, 125, 250, 1000, and 5000 nM, and incubated at 37 C for
48
hours in a humidified atmosphere containing 5% CO2 in air. Cells are
transferred
(100 L) to 96-well microtiter black-walled cell culture plates. The total
intracellular
ATP level is measured in a luminator (ClarityTM luminescence microplate
reader) with
the ATP Bioluminescence Assay Kit (ViaLight -Plus ATP monitoring reagent kit,
Lonza) following the manufacturer's instructions. Carbonyl cyanide-p-
trifiuormethoxy-phenylhydrazone (FCCP) and oligomycin are used as controls for
inhibition of ATP synthesis.
[0870] Results ¨ It is anticipated that cells derived from subjects suspected
of
having or diagnosed as having a mitochondrial disease or disorder will show
one or
more alterations associated with mitochondrial dysfunction such as decreased
cell
viability, loss of mitochondrial membrane potential, decreased cytochrome c
reduction, decreased cellular content of ATP, and reduced efficiency of
oxidative
phosphorylation. It is expected that treatment with mitochondrial fission
inhibitor
peptides (e.g., P110 and/or P110*) will reduce the severity or eliminate one
or more
of these alterations associated with mitochondrial dysfunction.
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[0871] These results will show that the mitochondrial fission inhibitor
peptides of
the present technology (e.g., P110 and/or P110*) are useful in methods for
normalizing and restoring mitochondrial bioenergetics generally.
Example 20 ¨ Use of Mitochondrial Fission Inhibitor Peptides in Combination
with
an Additional Therapeutic Agent in Ameliorating Symptoms of a Mitochondrial
Disease or Disorder in Subjects Diagnosed with a Mitochondrial Disease or
Disorder
[0872] This Example will demonstrate the use of mitochondrial fission
inhibitor
peptides of the present technology (e.g., P110 and/or P110*), in combination
with one
or more additional therapeutic agents (e.g., one or more of vitamins,
cofactors,
antibiotics, hormones, antineoplastic agents, steroids, immunomodulators,
dermatologic drugs, antithrombotic, antianemic, and cardiovascular agents) to
alleviate or ameliorate one or more symptoms in a subject diagnosed with a
mitochondrial disease. Suitable test subjects diagnosed with a mitochondrial
diasese
will exhibit one or more of the following symptoms: poor growth, loss of
muscle
coordination, muscle weakness, neurological deficit, seizures, autism,
autistic
spectrum, autistic-like features, learning disabilities, heart disease, liver
disease,
kidney disease, gastrointestinal disorders, severe constipation, diabetes,
increased risk
of infection, thyroid dysfunction, adrenal dysfunction, autonomic dysfunction,
confusion, disorientation, memory loss, failure to thrive, poor coordination,
sensory
(vision, hearing) problems, reduced mental functions, hypotonia, disease of
the organ,
dementia, respiratory problems, hypoglycemia, apnea, lactic acidosis,
seizures,
swallowing difficulties, developmental delays, movement disorders (dystonia,
muscle
spasms, tremors, chorea), stroke, and brain atrophy.
[0873] Subjects diagnosed with any mitochondrial disease or disorder described
herein and exhibiting one or more of the above symptoms are divided into 4
groups
(N=20) as follows: Group I is administered a daily dose of 0.5 mg/kg/day of
the
mitochondrial fission inhibitor peptides (e.g., P110 and/or P110*); Group II
is
administered a daily dose of between 0.01-10 mg/k/day of one or more of
vitamins,
cofactors, antibiotics, hormones, antineoplastic agents, steroids,
immunomodulators,
dermatologic drugs, antithrombotic, antianemic, and cardiovascular agents;
Group III
is administered a combination of a daily dose of 0.5 mg/kg/day of the
mitochondrial
fission inhibitor peptides (e.g., P110 and/or P110*) and a daily dose of
between 0.01-
mg/k/day of one or more of vitamins, cofactors, antibiotics, hormones,
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antineoplastic agents, steroids, immunomodulators, dermatologic drugs,
antithrombotic, antianemic, and cardiovascular agents; and Group IV is
administered
saline vehicle (control). Each group will receive therapy for six weeks. At
the end of
the six-week test period, subjects are evaluated for amelioration or
attenuation of one
or more of the symptoms described above.
[0874] It is anticipated that subjects in groups I and II will show an
improvement
(e.g., alleviation, amelioration) in at least one or more of the signs and
symptoms of
the mitochondrial disease or disorder as compared to the control group, Group
IV. It
is anticipated that subjects in Group III will exhibit a synergistic effect
with respect to
the combination therapy, and will exhibit a greater improvement in one or more
signs
or symptoms of the mitochondrial disease or disorder than the subjects of
Group I and
II.
[0875] These results will show that combination therapy, i.e., mitochondrial
fission
inhibitor peptides of the present technology (e.g., P110 and/or P110*) in
combination
with one or more additional therapeutic agents, is useful in reducing,
alleviating or
ameliorating one or more of the signs and symptoms associated with a
mitochondrial
disease or disorder.
EQUIVALENTS
[0876] The present technology is not to be limited in terms of the particular
embodiments described in this application, which are intended as single
illustrations
of individual aspects of the present technology. Many modifications and
variations of
the present technology can be made without departing from its spirit and
scope, as
will be apparent to those skilled in the art. Functionally equivalent methods
and
apparatuses within the scope of the present technology, in addition to those
enumerated herein, will be apparent to those skilled in the art from the
foregoing
descriptions. Such modifications and variations are intended to fall within
the scope
of the appended claims. The present technology is to be limited only by the
terms of
the appended claims, along with the full scope of equivalents to which such
claims are
entitled. It is to be understood that the present technology is not limited to
particular
methods, reagents, compounds compositions or biological systems, which can, of
course, vary. It is also to be understood that the terminology used herein is
for the
purpose of describing particular embodiments only, and is not intended to be
limiting.
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[0877] In addition, where features or aspects of the disclosure are described
in terms
of Markush groups, those skilled in the art will recognize that the disclosure
is also
thereby described in terms of any individual member or subgroup of members of
the
Markush group.
[0878] As will be understood by one skilled in the art, for any and all
purposes,
particularly in terms of providing a written description, all ranges disclosed
herein
also encompass any and all possible subranges and combinations of subranges
thereof Any listed range can be easily recognized as sufficiently describing
and
enabling the same range being broken down into at least equal halves, thirds,
quarters,
fifths, tenths, etc. As a non-limiting example, each range discussed herein
can be
readily broken down into a lower third, middle third and upper third, etc. As
will also
be understood by one skilled in the art all language such as "up to," "at
least,"
"greater than," "less than," and the like, include the number recited and
refer to ranges
which can be subsequently broken down into subranges as discussed above.
Finally,
as will be understood by one skilled in the art, a range includes each
individual
member. Thus, for example, a group having 1-3 cells refers to groups having 1,
2, or
3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3,
4, or 5
cells, and so forth.
[0879] All patents, patent applications, provisional applications, and
publications
referred to or cited herein are incorporated by reference in their entirety,
including all
figures and tables, to the extent they are not inconsistent with the explicit
teachings of
this specification.
[0880] Other embodiments are set forth within the following claims.
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