F-Spondin Inhibits Migration and Differentiation of Osteoclastic Precursors

Background: Clinically, severe cemental resorption is a rare consequence of periodontitis, although alveolar bone resorption by osteoclasts is one of the main pathologic changes. F-spondin is a secreted neuronal glycoprotein that localizes to the cementum. F-spondin is among the cementum-specific factors in periodontal tissue that have been reported. However, the effects of F-spondin on osteoclastogenesis have not yet been established. We examined the effects of F-spondin on stages of osteoclastogenesis, migration, and differentiation in a mouse osteoclastic precursor model, RAW 264 cells.Methods: RAW 264 cells were treated with recombinant F-spondin. Macrophage colony stimulating factor (M-CSF)–induced cell migration was examined by migration assay performed with cell culture inserts. Osteoclastic differentiation was measured by counting tartrate-resistant acid phosphatase (TRAP)–positive multinucleated cells.Results: In a transmigration assay, F-spondin significantly downregulated M-CSF–induced cell mig...