白藜芦醇介导SIRT2干预地塞米松诱导的骨髓间充质干细胞线粒体自噬

Study of resveratrol-mediated SIRT2 intervention in dexamethasone-induced mitophagy in bone marrow mesenchymal stem cells

目的探讨白藜芦醇(Res)通过SIRT2干预地塞米松(Dex)诱导骨髓间充质干细胞(BMSCs)线粒体自噬的作用机制。方法应用Res、Dex和SIRT2拮抗剂(NAM)分别作用小鼠BMSCs;使用透射电子显微镜(TEM)观察细胞线粒体自噬小体;采用Western blotting和实时PCR测定SIRT2、LC-3、Beclin-1、TOM20和Hsp60 mRNA和蛋白活性表达水平。结果Res以剂量依赖性和时间依赖的方式增强了BMSCs中SIRT2的表达;10^(-6)mol/L的Dex抑制了BMSCs细胞的增殖和活力,并且显著下调了BMSCs细胞内SIRT2 mRNA和蛋白活性的表达,而Res(10^(-6)mol/L)显著抑制了Dex对BMSCs细胞增殖及SIRT2表达的负性调控作用;Res(10^(-6)mol/L)显著增加了LC-3 mRNA和Beclin-1 mRNA的表达(P<0.05),显著降低了TOM20和Hsp60蛋白的表达水平(P<0.05)。结论Res通过介导SIRT2参与调控Dex诱导的BMSCs线粒体自噬。

Objective To investigate the mechanism of resveratrol(Res)-intervening dexamethasone(Dex)-induced mitochondrial autophagy in bone marrow mesenchymal stem cells(BMSCs)through SIRT2.Methods Mouse osteoblastic BMSCs were treated with Res,Dex,and the SIRT2 antagonist NAM.The mitochondria autophagosomes were observed using transmission electron microscopy(TEM).The protein and mRNA expression levels of SIRT2,LC-3,Beclin-1,TOM20,and Hsp60 were determined using Western blot-ting and reverse transcription-polymerase chain reaction(RT-PCR).Results Res enhanced SIRT2 expression in BMSCs in a dose-and time-dependent manner.Dex(10^(-6)mol/L)inhibited the proliferation and viability of BMSCs,and significantly down-regulated the expres-sion of SIRT2 mRNA and protein in BMSCs,whereas Res(10^(-6)mol/L)significantly inhibited the negative regulatory effects of Dex on the proliferation of and SIRT2 expression in BMSCs.Res(10^(-6)mol/L)significantly increased the mRNA expression of LC-3 and Beclin-1(P<0.05),but significantly decreased the protein expression of TOM20 and Hsp60(P<0.05).Conclusion Res plays a role in the regulation of Dex-induced mitochondrial autophagy in BMSCs by mediating SIRT2.