Mitochondrial DNA Damage and Animal Longevity: Insights from Comparative Studies

Figure 1

Schematic diagram of mitochondrial processes that are important for aging and longevity. The schematic shows that mitochondrial complex I is the main ROS generator. Several physiological mechanisms influencing the rate of mitochondrial ROS generation include: (i) the relative concentration of the respiratory complexes, (ii) the degree of electronic reduction of these generators, (iii) the uncoupling proteins, and (iv) specific chemical modifications. Oxygen radicals attack lipids, carbohydrates, proteins, and DNA. The products of lipid peroxidation include highly reactive molecules that can also cause lipoxidative damage to mitochondrial DNA. The scheme highlights two main characteristics of long-lived animal species likely contributing to their slow aging rate and superior longevity: highly resistant macromolecular components and low rate of generation of endogenous damage. Abbreviations: 8-oxodG, 8-oxo-7,8-dihydro-2′-deoxyguanosine; M1dG, Malondialdehyde-deoxyguanosine; HNE-dG, 4-hydroxy-2-nonenal-deoxyguanosine; HOPdG, Acrolein-deoxyguanosine.