Our long-term goal is to develop genetic approaches that could be used for the treatment of mitochondrial disorders associated with mitochondrial DNA (mtDNA) mutations. Although some of the approaches tested in the past showed some promise, they are inefficient and unlikely to reach clinical trials. We propose to develop approaches that are more efficient in improving oxidative phosphorylation in cells harboring heteroplasmic mtDNA mutations (i.e. a mixture of wild-type and mutated mtDNA). The approach is based on the """"""""mtDNA heteroplasmy shift"""""""" concept, where, by genetic manipulation, levels of the wild-type genome are increased in relation to the mutated genome. In the previous funding period we showed that mitochondria-targeted specific endonucleases are powerful tools to achieve mtDNA heteroplasmy shift The present proposal will continue to develop this approach. We will deliver mitochondria targeted restriction endonucleases systemically to muscle of a mouse model of mtDNA heteroplasmy and expect to see a generalized shift in mtDNA heteroplasmy in skeletal muscle. To expand the use of mitochondria nucleases, we will create novel zinc finger protein nucleases that can target common mtDNA mutations associated with mitochondrial disorders. When this approach moves into the clinical arena, it will be important to avoid secondary effects with potential clinical relevance, such as transient mtDNA depletion. To this end, we will test a model whereby the levels of mtDNA are increased (per cell) before the action of the specific mitochondrial restriction endonuclease. This should minimize a potential bioenergetic crisis associated with partial mtDNA depletion.

Public Health Relevance

Mitochondrial disorders are devastating diseases affecting the central nervous system, eyes, muscle and several other organ systems. At present, there are no treatments for mitochondrial disorders. We propose to develop a genetic approach that could be used as a therapy for a sub-group of mitochondrial disorders.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
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Special Emphasis Panel (ZRG1-GTIE-A (01))
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Chin, Hemin R
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University of Miami School of Medicine
Schools of Medicine
Coral Gables
United States
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Nissanka, Nadee; Moraes, Carlos T (2018) Mitochondrial DNA damage and reactive oxygen species in neurodegenerative disease. FEBS Lett 592:728-742
Pinto, Milena; Nissanka, Nadee; Moraes, Carlos T (2018) Lack of Parkin Anticipates the Phenotype and Affects Mitochondrial Morphology and mtDNA Levels in a Mouse Model of Parkinson's Disease. J Neurosci 38:1042-1053
Peralta, Susana; Goffart, Steffi; Williams, Sion L et al. (2018) ATAD3 controls mitochondrial cristae structure in mouse muscle, influencing mtDNA replication and cholesterol levels. J Cell Sci 131:
Garcia, Sofia; Nissanka, Nadee; Mareco, Edson A et al. (2018) Overexpression of PGC-1? in aging muscle enhances a subset of young-like molecular patterns. Aging Cell 17:
Arguello, Tania; Köhrer, Caroline; RajBhandary, Uttam L et al. (2018) Mitochondrial methionyl N-formylation affects steady-state levels of oxidative phosphorylation complexes and their organization into supercomplexes. J Biol Chem 293:15021-15032
Madsen, Pernille M; Pinto, Milena; Patel, Shreyans et al. (2017) Mitochondrial DNA Double-Strand Breaks in Oligodendrocytes Cause Demyelination, Axonal Injury, and CNS Inflammation. J Neurosci 37:10185-10199
Pinto, Milena; Pickrell, Alicia M; Wang, Xiao et al. (2017) Transient mitochondrial DNA double strand breaks in mice cause accelerated aging phenotypes in a ROS-dependent but p53/p21-independent manner. Cell Death Differ 24:288-299
Tengan, Celia H; Moraes, Carlos T (2017) NO control of mitochondrial function in normal and transformed cells. Biochim Biophys Acta Bioenerg 1858:573-581
Pinto, Milena; Nissanka, Nadee; Peralta, Susana et al. (2016) Pioglitazone ameliorates the phenotype of a novel Parkinson's disease mouse model by reducing neuroinflammation. Mol Neurodegener 11:25
Luo, Xueting; Ribeiro, Marcio; Bray, Eric R et al. (2016) Enhanced Transcriptional Activity and Mitochondrial Localization of STAT3 Co-induce Axon Regrowth in the Adult Central Nervous System. Cell Rep 15:398-410

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