Scientists reverse old-age symptoms in mice

It's not exactly the Fountain of Youth yet, but if you're a mouse--and the equivalent of 80 human years old--at the Dana-Farber Cancer Institute in Boston, you can thank a group of researchers for making you "young again." Never mind that you were genetically engineered to age prematurely. Your human handlers managed to reverse this and you went on to live a perfectly normal mouse lifespan.

The new research, which appears online in the journal Nature, represents the first time that age-related problems have been reversed in animals. The researchers engineered mice with all sorts of age-related problems, including small testes that produced little sperm, damaged intestines and sense of smell, and even shrunken brains that could produce no new cells.

"We stacked the deck against us and asked: Is there a point of no return?" Ronald DePinho, co-author of the paper, is quoted as saying by the Wall Street Journal. Then, researchers injected the mice with a drug that switched on a gene that stimulated telomerase production. Telomerase is an enzyme that makes small units of DNA, called telomeres, that seal the tips of chromosomes. When you age, telomeres get shorter.

A month after the treatment, the telomeres lengthened, new brain cells formed and spleens, testes and brains all grew in size on the grateful mice. It all worked out fine for these mice, but the researchers warn that they're a long way from trying it in humans. Like all attempts to recapture youth, this could come at a price. With increased telemorase could come an increased risk of cancer.

- read about the research in the Wall Street Journal
- and in Nature online