The Role of Mitochondrial DNA Mutation in Aging Remains Much Debated

Mitochondria are the power plants of the cell, deeply integrated into many core cellular processes, but most importantly, responsible for generating the energy store molecule adenosine triphosphate (ATP), used to power cellular processes. Mitochondria are descended from ancient symbiotic bacteria, and act like bacteria in many ways, fusing and dividing, and passing around component parts promiscuously. Every cell contains a herd of hundreds of these organelles, monitored by quality control processes that destroy worn mitochondria in order to maintain overall function. Importantly, mitochondria contain their own small circular genome. Mitochondrial DNA is less well protected than that of the cell nucleus, and more prone to stochastic mutational damage. There are clearly types of mitochondrial DNA damage, large deletion mutations that remove genes essential to the electron transport chain, central to mitochondrial function, that result in pathological damage to cells. But mitochondria throughout the body undergo a declining function with age that seems to have more to do with altered dynamics and the failure of mitophagy to keep up with worn mitochondria, a consequence of age-related changes in gene expression of crucial proteins. Yet mutational damage other than deletions, such as point mutations, is widespread across mitochondria in aged tissues. To what degree is this stochastic mutational damage important as a contribution to age-related mitochondrial decline?...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs