May 19, 2009

Embryo heartbeat drives stem cell creation

U.S. medical scientists say their discovery that an embryo's heartbeat drives blood cell formation might lead to new treatments for blood diseases.

Biologists have long wondered why the embryonic heart begins beating so early, before tissues actually need to be infused with blood.

Now two groups of researchers from Children's Hospital Boston, Brigham and Women's Hospital and the Harvard Stem Cell Institute say they have the answer. Using multiple lines of evidence from zebrafish, mice and mouse embryonic stem cells, the scientists said they discovered a beating heart and blood flow are necessary for development of the blood system, which relies on mechanical stresses to cue its formation.

The scientists said their studies -- published online May 13 by the journals Cell and Nature -- offer clues that might help in treating blood diseases such as leukemia, immune deficiency and sickle cell anemia.