低氧对小鼠成骨细胞Cyr61/CCN1表达的影响

Effects of hypoxia on expression of Cyr61/CCN1 in murine osteoblasts

目的探讨低氧环境对小鼠成骨细胞富含半胱氨酸61(Cyr61/CCN1)表达的影响。方法分别在氧浓度和去铁敏诱导的低氧环境下培养小鼠成骨细胞,Real-time PCR和Western blotting于不同时间点检测成骨细胞低氧诱导因子-1α(HIF-1α)、Cyr61/CCN1和血管内皮生长因子的表达。分别敲除小鼠成骨细胞中HIF-1α和VHL基因,检测细胞Cyr61/CCN1的表达。结果两种低氧环境下,小鼠成骨细胞HIF-1α通路被激活,Cyr61/CCN1 mRNA和蛋白表达均显著增加(P<0.05或P<0.01)。HIF-1α基因敲除小鼠成骨细胞Cyr61/CCN1 mRNA和蛋白表达均显著减少,VHL基因敲除成骨细胞Cyr61/CCN1 mRNA和蛋白表达均显著增加(P<0.05或P<0.01)。结论低氧环境通过激活HIF-1α通路来上调小鼠成骨细胞Cyr61/CCN1的表达。

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.