Molecular biologists may be on the brink of unleashing a cellular fountain of youth. In May Nils-Goran Larsson of the Karolinska Institute in Sweden pinpointed where the process of aging begins in a cell—the mitochondria—and thus where it may be slowed.
Mitochondria are tiny organelles that harness energy and turn it into a usable form. They are also the only structures outside a cell’s nucleus that contain their own DNA, and that turns out to be important. While DNA in the nucleus has an extensive system of proofreading and repairing enzymes, mitochondria depend mostly on a single protein to patch up mutations. When Larsson engineered mice with a defective, error-prone version of the protein, mice accumulated mutations unchecked. The results were startling. At young adulthood, Larsson’s mice resembled those three times their age, with bone and muscle loss, heart disease—even baldness.
The study is the first hard evidence that these ...
