Posted on 03/25/2010 12:24:33 AM PDT by neverdem
Doctors who have treated heart attack patients with injections of stem cells have had little success so far in making the heart regenerate its stricken tissues. Researchers have now discovered that in nature, hearts are regenerated in a quite different way, one that does not depend on stem cells.
The finding may explain the lack of clinical success with the stem cells, as well as suggest new approaches.
Humans can regenerate the liver but cannot replace limbs and other organs. But fish and...
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Charles Murry, an expert on heart cell biology at the University of Washington in Seattle, said the two reports raised the tantalizing question of why human hearts could not complete the regeneration process. In human hearts, too, Dr. Murry said, the muscle cells dedifferentiate after injury and double up their DNA, a necessary precursor to cell division. But they do not finish the process, for reasons that are so far unknown.
Learning how to overcome that block may not be so easy, in Dr. Murry’s view. “It’s tempting to say ‘Let’s do it how nature does it,’ ” he said, “but we don’t know how nature does it. Some of the best molecular biologists in the world have been working on this for a couple of decades and it hasn’t cracked yet.”
Many heart patients have received injections of stem cells, often ones taken from their own bone marrow. But the beneficial effects have generally been unremarkable. “Many of the cell-based treatment protocols have proven modestly effective at best,” Stefan Janssens of the University of Leuven in Belgium concludes in the current Annual Review of Medicine.
Dr. Murry agreed that results had been disappointing, but said both approaches, using stem cell treatments and trying to understand nature’s favored recipe for regeneration, should be pursued in parallel.
(Excerpt) Read more at nytimes.com ...
Zebrafish heart regeneration occurs by cardiomyocyte dedifferentiation and proliferation
If you carve the roast beast, you’re heart will grow three sizes.
Links to the abstracts are in comment# 1, IIRC.
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