Potentiation of osteoclastogenesis by adipogenic conversion of bone marrowderivedmesenchymal stem cells

Bone marrow-derived mesenchymal stem cells (BMSCs) are the indispensable component of thebone marrow, being the common precursors for adipocytes and osteoblasts. We show here that adipogenicdifferentiation resulted in increase in the production of adipocyte markers, such as adiponectin,fatty-acid binding proteins (FABP4), peroxisome proliferator-activated receptor γ (PPARγ),as well as the receptor activator of nuclear-κB ligand (RANKL). Co-culture of osteoclast precursors(OCPs) with BMSCs-derived adipocytes significantly enhanced osteoclast differentiation withlow-dose RANKL, whose levels alone could not promote osteoclastogenesis. These results demonstratefor the first time that adipogenic differentiation of BMSCs plays a pivotal role in maintainingbone homeostasis.