SUNDAY, Nov. 28 (HealthDay News) -- U.S. scientists say they
have partially reversed age-related degeneration in mice, leading
to new brain and testes growth, improved fertility and the return
of lost cognitive function, or thinking skills.
The advance in aging science was achieved by working with
telomerase genes in the mice, said the team at the Dana-Farber
Cancer Institute in Boston.
The researchers developed mice with a controllable telomerase
gene. (Telomerase is an enzyme that helps maintain telomeres -- the
protective "caps" on the ends of chromosomes.) As people age, low
levels of telomerase lead to progressive erosion and shortening of
the telomeres, resulting in physical and mental decline, the study
authors explained in a news release from the institute.
Creating mice with a controllable telomerase switch enabled the
scientists to create prematurely aged mice. The switch also enabled
the team to determine that reactivating telomerase in the mice
could restore telomeres and reduce the signs and symptoms of
In addition, the mice did not show signs of cancer -- a key
concern because cancer cells can use telomerase to make themselves
virtually immortal. Researchers noted that this is an important
area of study for future investigation.
In the future, it may be possible to use this approach to treat
people with conditions such as rare genetic premature aging
syndromes, in which shortened telomeres play an important role,
said study senior author Dr. Ronald A. DePinho, director of
Dana-Farber's Belfer Institute of Applied Cancer Science.
"Whether this would impact on normal aging is a more difficult question," he said in the news release. "But it is notable that telomere loss is associated with age-associated disorders and thus restoration of telomeres could alleviate such decline."
DePinho also said the study may lead to new directions for
regenerative medicine because the findings suggest that dormant
adult stem cells in extremely aged tissues remain viable and can be
reactivated to repair tissue damage.
"If you can remove the underlying damage and stresses that drive the aging process and cause stem cells to go into growth arrest, you may be able to recruit them back into a regenerative response to rejuvenate tissues and maintain health in the aged," he said in the release.
The study was released online in advance of publication in an
upcoming print issue of the journal
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