Drugs Reveal Another Possible Cause of Aging

Early but intriguing research on mice suggests a new mechanism of aging, and possibly a way to stall it. Drugs designed to target one aspect of aging also seem to help repair DNA damage and regulate gene activity, preventing them from going haywire with the stresses of time. "In principle, we now could have a way of reversing the effects of aging," said David Sinclair, a Harvard University gerontologist and co-founder of Sirtris Pharmaceuticals, a company best-known for its development of an experimental drug called resveratrol. Resveratrol and similar compounds activate an enzyme called SIRT1. The enzyme rejuvenates mitochondria, the machines that power our cells. Mitochondrial breakdown has been associated with many age-related diseases, including heart disease, diabetes and dementia. Several labs in addition to Sirtris are researching compounds that target mitochondria. The new findings suggest that SIRT1 fixes DNA in addition to mitochondria. Sinclair's team found that unless SIRT1 enzymes gathered at sites where DNA had started to unravel, other DNA repair proteins failed to arrive. This allowed damage to progress, eventually causing dormant genes to come alive, a process called deregulation.

http://blog.wired.com/wiredscience/2008/11/mitochondria-dr.html