Scientists have turned back the clock in mice they engineered to age faster than normal, an advance they suggest is the first time aging in mice has been reversed.
“We at best expected it to be a slowing of the process or perhaps an arresting of the process. We did not anticipate that it would be so dramatic a reversal in all of the problems that the animal was experiencing,” said Dr. Ronald DiPinho, professor of medicine and genetics at Dana-Farber Cancer Institute and Harvard Medical School, and co-author of the paper published Sunday in the journal Nature. “We were so struck by the findings that we rushed to get the study published.”
A human cell holds 23 pairs of chromosomes, each containing protective caps at each end called telomeres. Enzymes called telomerases protect the telomeres and reduce DNA damage thought to contribute to tissue aging. But as we age, our cells produce less telomerase; telomeres are cut shorter and eventually fail to protect DNA from damage.
Researchers boosted telomerase in the mice cells — which hold 20 pairs of chromosomes — to prevent telomeres from getting shorter. They found restoring the enzyme not only stopped aging but revived failing organs and even restored dark fur to mice who had turned grey. DePinho said the mice that were equivalent to ages 80 to 90 in human years returned to the equivalent of middle age.
“This [research] indicates there’s a point of return for these tissues,” said DePinho. “The fact that you can bring a tissue to the brink and then bring it back this dramatically is remarkable.”
Source: ABC News