Abstract:

Objective To investigate the effects of hypoxia on the expression of cysteine-rich protein 61(Cyr61/CCN1) in murine osteoblasts. Methods Murine osteoblasts were cultured under oxygen of lower concentration or treated with desferrioxamine, and Real-time PCR and Western blotting were employed to detect the expression of HIF-1α, Cyr61/CCN1 and vascular endothelial growth factor in osteoblasts at different time points. HIF-1α gene or VHL gene were knocked out in murine osteoblasts, and the expression of Cyr61/CCN1 in murine osteoblasts was detected. Results HIF-1α pathway was activated in murine osteoblasts under the condition of hypoxia, and the expression of Cyr61/CCN1 in osteoblasts was significantly increased （P<0.05 or P<0.01）. The expression of Cyr61/CCN1 was significantly decreased in murine osteoblasts with HIF-1α gene knockout, and that was significantly increased in osteoblasts with VHL gene knockout （P<0.05 or P<0.01）. Conclusion The expression of Cyr61/CCN1 in murine osteoblasts may be up-regulated by hypoxia through activation of HIF-1α pathway.

Key words: hypoxia, hypoxia inducible factor-1α, osteoblasts, Cyr61/CCN1, vascular endothelial growth factor