黄芪多糖抑制缺氧/复氧损伤乳鼠心肌细胞凋亡与自噬机制研究

Mechanism of astragalus polysaccharides inhibiting cardiomyocyte apoptosis and autophagy in neonatal rats injured by hypoxia/reoxygenation

目的:探讨黄芪多糖(APS)对缺氧/复氧(H/R)所致乳鼠心肌细胞凋亡与自噬抑制作用的相关机制。方法:分离并体外培养乳鼠心肌细胞3 d后制备H/R损伤细胞模型,设正常对照组、H/R组、APS低、中、高剂量(20、40、80μmol/ml)组,各组于造模前30 min给药处理。复氧2 h后,CCK-8法检测细胞增殖抑制率,Annexin V-FITC/PI染色法检测细胞凋亡水平,Western blot法检测p-Akt、Cleaved Caspase-3、Bcl-2、Bax、p-mTOR、Beclin1、LC3、P62蛋白表达。结果:与H/R组比较,APS中、高剂量细胞增殖抑制率和凋亡率显著降低(P<0.01),p-Akt、p-mTOR、Bcl-2表达量显著升高而Cleaved Caspase-3、Bax、Beclin1、LC3-Ⅰ、LC3-Ⅱ、P62表达量显著降低(P<0.05),Bcl-2/Bax比值显著升高、LC3-Ⅱ/LC3-Ⅰ比值显著降低(P<0.01)。结论:APS可能通过激活Akt/mTOR通路调控凋亡和自噬相关蛋白表达,对H/R所致乳鼠心肌细胞凋亡与自噬起到抑制作用。

Objective:To investigate the mechanism of astraglus polysaccharides(APS)inhibiting cardiomyocyte apoptosis and autophagy of neonatal rats injured by hypoxia/reoxygenation(H/R).Methods:After isolating and culturing neonatal rat cardiomyocytes in vitro for 3 days,the H/R injured cell model was prepared and set normal control group,H/R group and APS low,medium,high-dose(20,40,80μmol/ml)group,and the drug was given at 30 min before modeling.2 h after reoxygenation,the cell proliferation inhibition rate was detected by CCK-8 method,the cell apoptosis level was detected by Annexin V-FITC/PI staining;the expression of p-Akt,Cleaved Caspase-3,Bcl-2,Bax,p-mTOR,Beclin1,LC3,P62 proteins were detected by Western blot method.Results:Compared with H/R group,the proliferation inhibition rate and apoptosis rate were significantly decreased of neonatal rat cardiomyocytes in APS medium,high dose groups(P<0.01);the expression of p-Akt,p-mTOR,Bcl-2 were significantly up-regulated and the expression of Cleaved Caspase-3,Bax,Beclin1,LC3-Ⅰ,LC3-Ⅱ,P62 were significantly down-regulated(P<0.05);the ratio of Bcl-2/Bax was increased and LC3-Ⅱ/LC3-Ⅰwas decreased(P<0.01).Conclusion:APS may regulate the expression of apoptosis and autophagy-related proteins by activating the Akt/mTOR pathway,and inhibit the apoptosis and autophagy of neonatal rat cardiomyocytes induced by H/R.