The authors used oc/oc mice, which a loss of osteoclast (OCL) activity, to investigate the role of osteoblasts (OBLs) and OCLs in the development of the hematopoietic stem cell (HSC) niche. They found that the absence of OCL activity resulted in a defective HSC niche, an increased proportion of mesenchymal progenitors, reduced osteoblastic differentiation and impaired HSC homing to the bone marrow. Restoration of OCL activity reversed the defect in HSC niche formation. These data demonstrate that OBLs are required for establishing HSC niches and that osteoblastic development is induced by OCLs.
Mansour A, Abou-Ezzi G, Sitnicka E, W Jacobsen SE, Wakkach A, Blin-Wakkach C.