A View Of Mitochondrial Damage With Age
Mitochondrial damage and loss of function with age is an important contribution to many forms of age-related disease, dysfunction and degeneration. Here, an overview of some of the nuts and bolts of that damage: "high-throughput transcription profiles of genes coding for mitochondrial proteins in ventricles from adult (6-months) and aged (24-months) rats were compared using microarrays. Out of 614 genes encoding for mitochondrial proteins, 94 were differentially expressed with 95% downregulated in the aged. The majority of changes affected genes coding for proteins involved in oxidative phosphorylation ... gene expression changes in aged hearts translated into a reduced mitochondrial functional capacity ... aging induces a selective decline in activities of oxidative phosphorylation complexes I and V within a broader transcriptional downregulation of mitochondrial genes." Recall that oxidative phosphorylation is the more efficient mode of operation for mitochondria, and that loss of oxidative phosphorylation is the first step in the mitochondrial free radical theory of aging.