Corylin inhibits osteoclastogenesis and attenuates postmenopausal osteoporosis in mice / 中国组织工程研究

ABSTRACT

BACKGROUND: The balance of bone homeostasis is mediated by the osteoclast-related bone resorption and osteoblast-related bone formation. Over-activation of osteoclasts results in a series of bone metabolic diseases including rheumatoid arthritis and osteoporosis. The activation of nuclear factor-κB pathway induced by receptor activator of nuclear factor-κB ligand (RANKL) plays an important role in osteoclastogenesis. OBJECTIVE: To explore the effect of corylin on RANKL-mediated osteoclastogenesis. METHODS: RAW264.7 cells were incubated with 0, 1, 2, 4, 8, 16, 32, 64, 128 μmol/L corylin. The cytotoxicity of corylin was detected by cell counting kit-8 assay. RANKL induced the differentiation of RAW264.7 cells into osteoclasts, during which 2, 5, 10 μmol/L corylin was given. The number of osteoclasts was analyzed by TRAP staining after 5 days of intervention and the morphology and function of osteoclasts were analyzed by F-actin staining. Bone resorption assay was conducted after 2 days of intervention. The activation of nuclear factor-κB pathway was detected by western blot at 0, 15, 30, and 60 minutes of intervention. Then in vivo experiments were carried out, and the ovariectomized mice were intraperitoneally given 10 mg/kg twice a week. After 6 weeks of intervention, mouse femurs were taken for morphological analysis. RESULTS AND CONCLUSION: There was no cytotoxicity of corylin below the concentration of 16 μmol/L. Corylin inhibited osteoclastogenesis in a dose-dependent manner. Corylin inhibited the formation of F-actin and resorption activity of osteoclasts. Corylin inhibited RANKL-mediated nuclear factor-κB pathway. Corylin treatment reduced the bone loss in postmenopausal osteoporosis mice. Overall, corylin inhibits osteoclastogenesis via blocking nuclear factor-κB pathway and attenuates postmenopausal osteoporosis.