Scientists partially reverse aging in mice

Not only were scientists able to stop the clock, they’ve also found a way to partially reverse age-related degeneration in mice, according to a new US study published online in the journal Nature.

In the study, researchers were able to reverse age-related genetic damage in mice, which led to the return of lost cognitive function and thinking skills as well as improved fertility, according to lead author Ronald DePinho, director of Dana-Farber’s Belfer Institute of Applied Cancer Science and a Harvard Medical School professor of genetics.

The advance in aging science involved working with telomerase genes in the mice. Telomerase is an enzyme that helps to maintain telomeres, or the protective ‘caps’ on the ends of chromosomes. As people age, low levels of telomerase can cause an erosion and shortening of the telomeres, which in turn results in a steady physical and mental decline. In short, loss of telomeres — which is associated with a number of age-associated disorders — causes cells to self-destruct or go into retirement, organs to atrophy and brain cells to die.

In a feat of genetic engineering, researchers were able to create mice with a controllable telomerase switch. This enabled them to create prematurely aged mice with entrenched age-related disease — and then to restore the telomeres to see if aging would then stabilize or slow down.

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The result? The mice showed a dramatic reversal in many of the symptoms of aging, including brain disease and infertility.

And, importantly, the mice did not show signs of cancer, which was a concern because cancer cells can use telomerase to make themselves virtually immortal.

So what does this mean for people?

It may have been a merry day for mice — but whether or not the findings could eventually lead to a fountain of youth for humans is still unclear, researchers say.

“While human applications remain in the future, the strategy might one day be used to treat conditions such as rare genetic premature aging syndromes in which shortened telomeres play an important role,” DePinho said in a news release.

“Whether this would impact on normal aging is a more difficult question,” he added, “But it is notable that telomere loss is associated with age-associated disorders and thus restoration of telomeres could alleviate such decline.”

The results may also provide new avenues for regenerative medicine because they suggest that inactive adult stem cells in severely aged tissues remain viable and can be reactivated to repair tissue damage.

“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,” researchers concluded.

Sources: Dana-Farber Cancer Institute, news release, Nov. 28, 2010; journal Nature; HealthDay News

Photo ©iStockphoto.com/ dra_schwartz

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