Bone cells help call the shots for the blood's stem ce...( Just as oak barrels don't simply hold f...),Health

In some sense the finding by scientists at the University of Rochester Medical Center, Harvard Medical School and Massachusetts General Hospital may not seem startling after all, it's long been known that the bone marrow that is the source of all our blood cells is in the center of our longest bones. But the team's paper in the Oct. 23 issue of the journal Nature is the first to pinpoint the role of bone forming cells in controlling the expansion of blood-forming stem cells, and to identify a way to multiply such cells without pushing them along toward their ultimate cell fate.

The finding could be important for bone-marrow-transplant patients, for whom a limit in stem cells often makes the procedure more dangerous if not impossible. By exploiting their knowledge of the bone's role in the creation of blood cells, the team was able to create mice that were nearly four times as likely to survive a difficult transplant as other mice. The bone marrows of the treated mice looked much healthier and were more densely packed with blood cells.

"This started as a rather improbable project, a side project that became more and more interesting as we made our findings," says Laura Calvi, M.D., of the University of Rochester Medical Center, who is the first author and an endocrinologist in the Department of Medicine. "It's especially exciting because the compound we used is already known to work safely in people, so we can start looking quickly to see whether this strategy will work in people too."

Calvi began the work when she was a physician at Massachusetts General Hospital. A physician who specializes in treating patients with osteoporosis, she was curious about the workings of parathyroid hormone, a molecule long
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Contact: Tom Rickey
trickey@admin.rochester.edu
585-275-7954
University of Rochester Medical Center
22-Oct-2003