The researchers at the Joslin Diabetes Center said their discovery could have major implications for the future of bone marrow and blood cell transplantation.

Every year, some 45,000 people undergo bone marrow or peripheral blood progenitor cell transplantation for treatment of a variety of diseases, including leukemia, lymphoma and immunodeficiency. The Joslin scientists say blood cell transplantation might also one day help people with diabetes better tolerate islet cell transplants without the need for prolonged use of powerful immunosuppressive drugs.

In studying mice that lack the transcription factor early growth response gene, or EGR-1, a Joslin team led by Amy Wagers, found hematopoietic stem cells in the marrow of the mice divided about twice as often as stem cells in mice with the gene. Mice lacking EGR-1 also had higher numbers of such stem cells circulating in their blood.

The study is the first to identify EGR-1 as a regulator of hematopoietic stem cell migration and proliferation.

The research is reported in the journal Cell Stem Cell.