大麻素II型受体参与调控低氧微环境下大鼠骨髓间充质干细胞的骨向分化

目的：研究大麻素II型受体（CB2）对低氧微环境调控骨髓间充质干细胞（BMSCs）骨向分化的作用及其调控机制。方法：全骨髓细胞贴壁法分离培养rBMSCs。应用化学低氧剂CoCl2建立低氧模型，实时荧光定量PCR和Western blot检测成骨关键蛋白RUNX2、OCN在基因和蛋白水平的表达，评估骨向分化能力。进一步结合CB2抑制剂AM630探讨CB2在低氧微环境下介导rBMSCs骨向分化中的作用。结果：与对照组比，低氧处理24、48、72、96 h后rBMSCs的RUNX2、OCN mRNA和蛋白表达量显著上升（P＜0.05）；同时低氧处理上调CB2 mRNA和蛋白表达（P＜0.05）。CB2抑制剂AM630下调低氧所促进的RUNX2、OCN的表达（P＜0.05）。结论：CB2参与低氧促进rBMSCs的成骨分化的调控。

The role of cannabinoid type 2 receptor in mediating osteogenic differentiation induced by hypoxia in rat bone mesenchymal stem cells

Objective: To explore whether cannabinoid type 2 receptor (CB2) participates in the regulation of BMSCs osteogenic differentiation and how it is regulated by hypoxic microenvironment. Methods: The whole bone marrow cell adherence method was used to isolate and culture rBMSCs. Low-oxygen model was established by using different concentrations of chemical oxygen peroxide cobalt chloride (CoCl2). Real-time PCR and Western blotting were used to detect the expression of osteogenesis key proteins RUNX2 and OCN at the gene and protein levels. Further, combined with the CB2 inhibitor AM630, the role of CB2 in the osteogenic differentiation of rBMSCs in a hypoxic microenvironment was investigated. Results: Compared with the control group, the expression of RUNX2 and OCN mRNA and protein in rBMSCs increased significantly at 24, 48, 72, 96 h after hypoxia treatment (P<0.05); Oxygen treatment up-regulated mRNA and protein expression of CB2 (P<0.05). CB2 inhibitor AM630 inhibited the expression of RUNX2 and OCN induced by hypoxia (P<0.05). Conclusion: CB2 is involved in the regulation of osteogenic differentiation of rBMSCs promoted by hypoxia.