Biologists at UC San Diego have identified the specific region in vertebrates where adult blood stem cells arise during embryonic development.
Their discovery, which appears in a paper in this week's early online edition of the journal Nature, is a critical first step for the development of safer and more effective stem cell therapies for patients with leukemia, multiple myeloma, anemia and a host of other diseases of the blood or bone marrow.
The researchers say their time-lapse imaging of the process, by which primitive embryonic tissues first produce the parent stem cells that produce all adult blood cells over the life of an individual, should help guide future efforts to repair and replace this cell population for therapeutic purposes.
Current transplantation therapies rely on the infusion of donor stem cells into a patient's bone marrow to generate new, healthy blood cells without disease. But that procedure is often risky and can result in fatal complications, due in part to "graft-versus-host disease," in which transplanted cells react against foreign tissues of the recipient. One means of circumventing this immune rejection problem would be to generate hematopoietic stem cells, or HSCs, using the patient's own precursor cells. Such cells would be perfectly genetically matched, but in order to generate such cells, scientists must first understand the molecular processes that underlie specification of HSCs.
"If we could generate healthy HSCs from patients and transplant them back into their own bone marrow, it would eliminate many complications," said David Traver, an assistant professor of biology who headed the research team.
"Our findings are an important step toward this goal because they provide a better understanding of how HSCs, the cell type responsible for the clinical benefits of bone marrow transplants, are first specified during development," he said. "This improved und
|Contact: Kim McDonald|
University of California - San Diego