From Nature:
Premature ageing can be reversed by reactivating an enzyme that protects the tips of chromosomes, a study in mice suggests.
Mice engineered to lack the enzyme, called telomerase, become prematurely decrepit. But they bounced back to health when the enzyme was replaced. The finding, published online today in Nature1, hints that some disorders characterized by early ageing could be treated by boosting telomerase activity. It also offers the possibility that normal human ageing could be slowed by reawakening the enzyme in cells where it has stopped working, says Ronald DePinho, a cancer geneticist at the Dana-Farber Cancer Institute and Harvard Medical School in Boston, Massachusetts, who led the new study. “This has implications for thinking about telomerase as a serious anti-ageing intervention.”
More here.