Antiosteoclastogenic Activity of Silicate-based Materials Antagonizing Receptor Activator for Nuclear Factor KappaB Ligand–induced Osteoclast Differentiation of Murine Marcophages

IntroductionThis study investigated whether calcium silicate cement extract exerted antiosteoclastogenic actions in murine RAW 264.7 macrophages cultured with receptor activator for nuclear factor kappaB (RANKL).MethodsThe RAW 264.7 macrophage cell was treated with RANKL to osteoclastogenesis. Then, cell viability, cell death, and cathepsin K expression were examined.ResultsThe silicon (Si)-inhibited RANKL-induced formation of osteoclasts during the osteoclast differentiation process. It was also found that ≥4 mmol/L Si reduced RANKL-enhanced tartrate-resistant acid phosphatase (TRAP) activity in a dose-dependent manner. Furthermore, Si diminished the expression and secretion of cathepsin K elevated by RANKL and was concurrent with the inhibition of TRAF6 induction and nuclear factor kappaB activation.ConclusionsThe current report shows that silicate abrogated RANKL-induced osteoclastogenesis by retarding osteoclast differentiation. The Si can modulate every cell through dose-dependent in vitro RANKL-mediated osteoclastogenesis, such as the proliferation and fusion of preosteoclasts, and the function of osteoclasts. Therefore, silicate-based materials may be a potential therapeutic agent targeting osteoclast differentiation in bone defects.