【摘要】 目的：探讨黄芪甲苷（Astragaloside IV,ASIV）对高糖（high glucose,HG）环境下大鼠心肌H9c2细胞系自噬水平的调控作用及相关机制。方法：高浓度（33.3 mmol/L）葡萄糖对H9c2细胞进行干预，建立HG体外损伤模型。将细胞分为低糖（5.5 mmol/L葡萄糖）对照（control）组、HG组、HG+ASIV(100μmol/L)组和HG+ASIV(100μmol/L)+Compound C(5μmol/L)组。CCK-8法检测H9c2细胞活力；乳酸脱氢酶（lactate dehydrogenase,LDH）试剂盒检测细胞损伤；Western blot检测微管相关蛋白轻链3(microtubule-associated protein light chain 3,LC3)-I、LC3-II、beclin-1、p62及AMP活化蛋白激酶（AMP-activated protein kinase,AMPK）/Unc-51样激酶1(Unc-51-like kinase 1,ULK1)信号通路相关蛋白的表达变化；免疫荧光法检测LC3B表达。结果：100μmol/L ASIV可显著抑制HG诱导的心肌细胞活力下降（P<0.05），减少HG条件下LDH释放（P<0.05）;ASIV可显著逆转HG诱导的心肌细胞LC3-II/LC3-I比值、beclin-1蛋白表达水平及AMPK和ULK1磷酸化水平的下降，以及p62蛋白的高表达（P<0.05），使HG条件下受到抑制的LC3B荧光强度增加。ASIV促进自噬以及增加AMPK和ULK1磷酸化的作用可被AMPK抑制剂Compound C阻断。结论：ASIV可能通过调节AMPK/ULK1信号通路提高大鼠心肌H9c2细胞自噬水平，从而减轻心肌细胞的HG损伤。更多还原

【Abstract】 AIM:To investigate the effect of astragaloside IV(ASIV)on autophagy of H9c2 rat cardiomyocytes under high glucose(HG)condition.METHODS:High concentration(33. 3 mmol/L)of glucose was used to induce HG-induced injury of H9c2 cells. The H9c2 cells were divided into low glucose(5. 5 mmol/L glucose)control group,HG group,HG+ASIV(100 μmol/L)group and HG+ASIV(100 μmol/L)+Compound C(5 μmol/L)group. CCK-8assay was used to detect cell viability. Cell damage was evaluated by lactate dehydrogenase(LDH)kit. Western blot was used to detect the expression of microtubule-associated protein light chain 3(LC3)-I,LC3-II,beclin-1,p62 and AMP-activated protein kinase/Unc-51-like kinase 1(AMPK/ULK1)signaling pathway-related proteins. Immunofluorescence was used to detect the expression of LC3B in H9c2 cells.RESULTS:Treatment with 100 μmol/L ASIV rescued the decline of cell viability and reduced the release of LDH induced by HG significantly(P<0. 05). Treatment with ASIV reversed the decreases in LC3-II/LC3-I ratio,beclin-1 expression,and phosphorylation of AMPK and ULK1 induced by HG,and significantly decreased the high expression of p62 protein induced by HG(P<0. 05). It also stimulated the fluorescence intensity of LC3B. The effect of ASIV on autophagy was blocked by Compound C,an AMPK inhibitor.CONCLUSION:Treatment with ASIV promotes the autophagy of H9c2 cells induced by HG via AMPK/ULK1 signaling pathway.更多还原