Identification of genes differentially expressed in osteoclast-like cells.

Homeostasis of the skeletal system is maintained by a balance between bone formation and resorption. The receptor activator of NF-kappaB ligand (RANKL) induces the differentiation of bone-resorbing cells, osteoclasts. To identify genes regulated during osteoclast differentiation, we constructed a subtraction cDNA library using a mouse RAW264 macrophage cell line that differentiates into osteoclast-like multinucleated cells after treatment with RANKL.

RANKL-induced DC-STAMP is essential for osteoclastogenesis.

Osteoclasts are bone-resorbing, multinucleated giant cells that are essential for bone remodeling and are formed through cell fusion of mononuclear precursor cells. Although receptor activator of nuclear factor-kappaB ligand (RANKL) has been demonstrated to be an important osteoclastogenic cytokine, the cell surface molecules involved in osteoclastogenesis are mostly unknown. Here, we report that the seven-transmembrane receptor-like molecule, dendritic cell-specific transmembrane protein (DC-STAMP) is involved in osteoclastogenesis.