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.
Researchers at Harvard-affiliated medical centers genetically manipulated mice to age faster, and then used gene therapy to lengthen telomeres - compounds found at the ends of strands of DNA - which reversed age-related problems such as decreased brain function and infertility.
"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 contritube to tissue aging. But as we age, our cells produce less telomerase; telomeres are cut shorter and eventually fail to protect DNA from damage.