Origin of blood stem cells uncovered

Washington, Mar 13 (UNI) A long-standing biological mystery that might help scientists to grow blood stem cells in the lab to treat several human diseases, has been unearthed.

Researchers at the University of California, Los Angeles have discovered that blood stem cells, which later differentiate into all the cells in the blood supply, originate and are nurtured in the placenta.

The discovery, reported in the latest issue of the journal Cell Stem Cell, might allow scientiests to replicate the specific embryonic microenvironment necessary for development of blood stem cells and grow them for use in treating diseases like leukemia and aplastic anemia ''It is critical for us to learn how to make tissue specific stem cells by studying what happens during embryonic development,'' senior study author Dr Hanna Mikkola said in a statement.

Scientists now can take embryonic stem cells, the cells that can become any tissue type in the body, and coax them into becoming all the cells in the blood supply, such as red and white blood cells and platelets.

Currently, patients with certain types of leukemia are treated by transplanting bone marrow. However, there aren't nearly enough bone marrow donors to provide patients with perfect matches.

If blood stem cells could be grown, those cells could be transplanted into these patients. The blood stem cells would then differentiate into a new, and healthy, blood supply, the researches observed.

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