Roles of mitochondrial DNA in decoding aging and aging related disorders

Small mitochondrial DNA (mtDNA) encodes factors critical for oxydative phosphorylation and subunits of the electron transport chain where carbohydrates and fats are oxidized to generate carbon dioxide, water and ATP.This review paper describes the evolution of mitochondrial DNA and its role in ageing. A decline in mitochondrial function plays a key role in the aging process and increases the incidence of age-related disorders. Mitochondrial dysfunction and oxidative stress are two interdependent damage mechanisms that play a central role in brain aging. Oxidative stress initiated and propagated by active oxyradicals and various other free radicals in the presence of catalytic metal ions can damage the phospholipid, protein and DNA molecules within the cell. Mitochondrial dysfunction has been implicated in premature aging, age-related diseases, and tumor initiation and progression. The mechanisms involved altered production of mitochondrial ROS, altered regulation of the nuclear epigenome, affected initiation of apoptosis, and a limiting effect on the production of ribonucleotides and deoxyribonucleotides.The latter part of the paper include the strategies to slow the mitochondrial DNA mutation and antioxidant supplementation for the prevention and treatment mtDNA mutation related disorders. The newly developed mitochondria-targeted antioxidants have brought a new direction to experimental studies related to oxidative damage and they may provide potential drugs in near future for a variety of diseases including brain aging and neurodegenerative disorders.