UCLA scientists have shown how a unique protein in human bone marrow can drive stem cells to repair our blood system after an injury. The discovery offers a roadmap that could lead to more effective radiation and chemotherapy treatments for people with cancer and other blood-related diseases.
Hematopoietic stem cells were a key to the new study. Scientists have long investigated hematopoietic stem cells, which have the ability to become any other type of blood cell, such as red or white blood cells, to try to understand how bone marrow regulates and instructs them to regenerate and repair themselves.
In prior research, John P. Chute, MD, professor of hematology and radiation oncology, discovered that endothelial cells — the cells that make up the lining of blood vessels in our bone marrow — play a key role in telling hematopoietic stem cells how to renew and repair themselves. He theorized that following an injury or another stress to our body, the blood system as a whole benefits, as the activity in bone marrow directly drives the stem cells to promote and accelerate recovery. In the new study, Dr. Chute and colleagues built upon their earlier work to identify a new protein called pleiotrophin (PTN). They discovered that the protein binds to hematopoietic stem cells and that it is this process that activates the blood stem cells to stimulate the recovery of our entire blood system.