Effects of Ca2+/calmodulin-dependent protein kinase pathway inhibitor KN93 on osteoclastogenesis

摘要

The aim of the present study was to determine the effects of the Ca2+/calmodulin-dependent protein kinase pathway inhibitor KN93 on osteoclastogenesis. RAW264.7 cells were incubated with macrophage colony-stimulating factor (M-CSF) + receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL) to stimulate osteoclastogenesis and then treated with 10 mu MKN93. The methods included tartrate-resistant acid phosphatase (TRAP) staining, bone resorption activity assays, filamentous (F)-actin staining, determination of intracellular calcium ([Ca2+](i)) levels, monitoring of osteoclast-specific gene expression levels and measurement of key transcription factors protein levels. The results suggested that KN93 inhibited the formation of TRAP-positive multinucleated cells, shaping of F-actin rings and resorption activity of the cells. In addition, KN93 decreased the concentration of [Ca2+], expression levels of osteoclast specific genes and protein levels of critical transcription factors in the M-CSF + RANKL-induced osteodast model. In summary, KN93 may directly affect the differentiation and activation of ostcoclasts, potentially through the Ca2+/calmodulin-dependent protein kinase signaling pathway.