There has been a great deal
of interest in the idea of using stem cells to reverse age-associated declines in
organ function. However, recent studies have shown that ageing tissues often have
plenty of stem cells; nonetheless, the stem cells lose their ability to
differentiate and to repopulate tissues with healthy cells. Now, in recent
issues of SCIENCE (1) and NATURE
MEDICINE (2), several research reports have shown that factors in the blood
of young mice can reverse age-related declines in stem cell and tissue
function. Some of these studies used parabiosis, that is joining the
circulatory systems of old and young animals. Another study focused on GDF11, a
TGF-beta type growth factor whose expression declines in older animals. Injections
of this protein improved both muscle function and (in another report) growth of
brain blood vessels and olfactory neurons. Perhaps the most exciting study (2)
demonstrated that blood from young mice could reverse age-related declines in
hippocampal cells and associated cognitive impairments.
There has always been tremendous
interest in seeking means to slow the declines associated with ageing. However,
the work discussed here, as well as other recent studies, suggest that an
actual reversal (at least in part) of the ageing process may be possible. While
this is all still far away from use in humans, it offers a tantalizing prospect
that could have enormous implications both medically and in terms of impacts on
society.
(1)
(2)
http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.3569.html
No comments:
Post a Comment