二甲双胍通过AMPK/PPAR-γ通路诱导自噬抑制高糖对血管平滑肌细胞的增殖作用

Metformin Inhibits high Glucose-induced Vascular Smooth Muscle Cells Proliferation by Promoting Autophagy via AMPK/PPAR-γ

目的探讨二甲双胍(Metformin)对高糖培养的小鼠主动脉血管平滑肌细胞(vascular smooth muscle cell,VSMCs)自噬、细胞增殖的影响及其调控机制。方法用Western blot检测不同处理组微管相关蛋白轻链-3-Ⅱ(LC3-Ⅱ),Becline-1蛋白水平变化,透射电镜观察各处理组VSMCs自噬小体水平;用Western blot检测不同处理组p-AMPK/AMPK、PPAR-γ蛋白表达水平;用EDU法检测不同处理组VSMCs增殖情况。结果二甲双胍、雷帕霉素逆转高糖抑制VSMCs自噬的作用(P<0.001);Compound C、GW9662增加高糖抑制VSMCs自噬的作用(P<0.05);二甲双胍逆转高糖对AMPK/PPAR-γ通路的负调控(P<0.01);二甲双胍、雷帕霉素抑制高糖促进的VSMCs增殖(P<0.001),Compound C、GW9662逆转二甲双胍抑制高糖促VSMCs增殖的作用(P<0.05)。结论高糖促进VSMCs增殖可能是自噬调节相关的,二甲双胍可通过激活AMPK/PPAR-γ通路上调VSMCs自噬水平,抑制高糖促进的VSMCs异常增殖。

Objective To investigate the effect and regulatory mechanism of metformin on autophagy and cell proliferation of vascular smooth muscle cells(VSMCs)cultured in high glucose in mice aortic.Methods Western blot was used to detect the changes in microtubule-associated protein light chain 3-II(LC3-II)and Beclin-1 protein levels in different treatment groups.Transmission electron microscope was used to observe the the level of autophagosomes in VSMCs of each treatment group.Western blot was used to detect the expression levels of p-AMPK/AMPK and PPAR-γproteins in different treatment groups.The EDU method was used to detect the proliferation of VSMCs in different treatment groups.Results Metformin and rapamycin reversed the inhibitory effect of high glucose on VSMC autophagy(P<0.001).Compound C and GW9662 enhanced the inhibitory effect of high glucose on VSMC autophagy(P<0.05).Metformin reversed the negative regulation of high glucose on the AMPK/PPAR-γpathway(P<0.01).Metformin and rapamycin inhibited high glucose-induced VSMC proliferation(P<0.001),and Compound C and GW9662 reversed the inhibitory effect of metformin on high glucose-induced VSMC proliferation(P<0.05).Conclusion High glucose promotes the proliferation of VSMCs,which may be regulated by autophagy.Metformin can upregulate autophagy levels in VSMCs by activating the AMPK/PPAR-γpathway,thereby inhibiting the abnormal proliferation of VSMCs induced by high sugar.