Fat Cells in Bone Marrow Block Formation of New Blood Cells
This contradicts idea that fat cells act as space fillers
FRIDAY, June 12 (HealthDay News) -- Fat cells that migrate into the bone marrow with age or after chemotherapy or radiation block the formation of new blood cells rather than acting as space fillers, according to a study published online June 10 in Nature.
Olaia Naveiras, M.D., from Children's Hospital Boston, and colleagues investigated whether adipocytes that infiltrate hematopoietic red marrow influence hematopoiesis. They used normal mice, mice genetically incapable of forming adipocytes, and mice treated with a drug that blocks adipogenesis.
The researchers found that in normal mice, there were only 25 percent as many hematopoietic stem cells and up to three-fold fewer short-term progenitors in the adipocyte-rich tail vertebrae compared with the adipocyte-free thorax vertebrae. In mice lacking adipocytes, engraftment of bone marrow from normal mice, particularly of hematopoietic progenitors, after irradiation was faster than in normal mice or untreated mice.
"Collectively, our results contradict the classical dogma that adipocytes act as passive space fillers in the marrow," Naveiras and colleagues conclude. "These data implicate adipocytes as predominantly negative regulators of the bone-marrow microenvironment, and indicate that antagonizing marrow adipogenesis may enhance hematopoietic recovery in clinical bone-marrow transplantation."