Respiratory function decline and DNA mutation in mitochondria, oxidative stress and altered gene expression during aging

In this article, we discuss mitochondrial dysfunction, oxidative stress and altered gene expression during aging. Oxidative phosphorylation efficiency was decreased and mtDNA mutations and oxidatively damaged biomolecules accumulated in the somatic tissues of elderly subjects. In senescent skin fibroblasts induced by H ₂O ₂, the protein expression and activity levels of cytochrome c oxidase and the oxygen consumption rate were decreased. Moreover, the gene expression of pyruvate dehydrogenase was decreased but those of pyruvate dehydrogenase kinase and lactate dehydrogenase were increased. We suggest that the shift from mitochondrial respiration to glycolysis as the major supply of ATP is a biomarker of aging.