Age-reversing enzyme discovery

A METHOD of turning the clock back to rejuvenate organs in the body may be within sight, new research suggests.

By switching on an enzyme that holds back molecular ageing, scientists have been able to reverse tissue degeneration in mice.

Although the study provides only a “proof of concept”, drugs are already being developed that might do the same in humans.

If proven to be safe, a big “if”, such an approach may help to keep people evergreen, with young-looking skin, healthy bodies and alert brains.

The research, reported today in the journal Nature online, focuses on telomeres — caps on the end of chromosomes that shorten each time cells divide.

Telomeres act much like the plastic tips of shoelaces, preventing strands of DNA from fraying and sticking to one another.

As they wear away they reach a point where cells can no longer divide and die. This is one of the key elements to ageing, and occurs at different rates in different individuals.

The US scientists showed that reactivating an enzyme called telomerase can rebuild shortened telomeres — and reverse ageing.

In their study, the researchers used a drug called 4-hydroxytamoxifen to stimulate telomerase production in a strain of mice whose normal supply was shut off. Their fertility was impaired, they had tissue degeneration in the spleen and intestines and their brains had reduced in size.

But after just four weeks of treatment with 4-OHT their organs began to regenerate. Even the effects of ageing in the brain were reversed.

The scientists, led by Dr Ronald DePinho, from the Dana-Farber Cancer Institute in Boston, wrote: “This unprecedented reversal of age-related decline in the central nervous system and other organs vital to adult mammalian health justifies exploration of telomere rejuvenation strategies for age-associated diseases.”