Transcriptional profiles of genes in the early stage of osteoclastogenesis

Osteoclast (OC) differentiation undergoes a two-step process: commitment of hematopoietic progenitor cells to tartrate-resistant acid phosphatase (TRAcP) positive OC precursors (OCPs), and fusion of OCPs into multinucleated OCs. In order to identify transcriptional profiles of genes in the transitional phase between OC commitment and fusion in OCG, Affymetrix® Mouse Gene 1.0 ST arrays were performed on total RNA extracted from mouse (SV129/BL6 ) monocytes and pre-osteoclasts (pre-OCs), primed with macrophage colony-stimulated factor (M-CSF) or M-CSF and soluble recombinant receptor activator of NF-кB ligand (sRANKL), respectively. The analysis identified 656 RANKL-up or down-regulated in the early stage of osteoclastogenesis. Monocytes isolated from mouse bone marrow were stimulated with M-CSF and soluble RANKL (m + r), or M-CSF alone (m).