CFU-GM-derived cells form osteoclasts at a very high efficiency

The granulocyte-macrophage progenitor (CFU-GM) is a multipotent cell that c an differentiate to osteoclasts (OCLs), macrophages, or granulocytes, Howev er, the relative potential of CFU-GM to efficiently form OCLs is unknown. I n this report we demonstrate that granulocyte-macrophage colony-forming uni t (CFU-GM)-derived cells represent an easily obtainable highly purified sou rce of human OCL precursors that form OCLs at very high efficiency (greater than 90%) when cultured with RANK ligand (RANKL), macrophage colony-stimul ating factor (M-CSF), and dexamethasone, The OCLs that formed have high bon e-resorbing activity and form multiple resorption lacunae per OCL on dentin slices. Similarly, murine marrow-derived CFU-GM also formed OCLs at a high efficiency (>80%) when treated with RANKL, M-CSF, and dexamethasone. In co ntrast, more committed macrophage colony-forming unit (CFU-M)-derived cells form few OCLs under these conditions, (C) 2000 Academic Press.