Hematopoietic (blood-forming) stem cells produce all of the body’s blood cells. Defects in blood-forming stem cells can lead to myelodysplastic syndrome (MDS) and other blood cancers.

In a study involving zebrafish published online on March 1 in Developmental Cell, senior author Teresa Bowman, Ph.D., lead author Joshua Weinreb, and colleagues found that the protein encoded by the gene DDX41, which is mutated in some MDS patients, regulates the number of blood stem cells. MDS is characterized by an aberrant expansion of blood stem cells—and the researchers found that mutated DDX41 triggers inflammatory signaling that increases the number of hematopoietic stem cells. Discovering how aberrant DDX41 protein promotes hematopoietic stem-cell production adds to the list of potential targets for pharmaceutical intervention against MDS.

Dr. Bowman is an associate professor of developmental and molecular biology and of medicine at Einstein. Mr. Weinreb is a student in Dr. Bowman’s lab.