黄芪多糖对心肌过氧化氢损伤的保护机制研究

The protective effect and mechanism of Astragalus polysaccharide in hydrogen peroxide-induced cardiomyocyte injury

目的探索黄芪多糖(APS)对过氧化氢(H_(2)O_(2))诱发的大鼠心肌细胞H9C2的保护作用及可能机制。方法实验分为①对照组;②对照+APS组;③H_(2)O_(2)损伤组;④H_(2)O_(2)损伤+APS修复组,采用乳酸脱氢酶(LDH)漏出量测定、3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐[3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide,MTT]检测、免疫荧光染色、原位末端标记法(TUNEL)、逆转录-聚合酶链反应(RT-PCR)以及蛋白质印迹(WB)等实验方法,观察APS对H_(2)O_(2)引起的心肌细胞损伤、死亡的影响以及过氧化物酶体增殖物激活受体γ共激活因子1(PGC-1)/肌肉因子(irisin)信号通路在其中的参与情况。结果与对照组相比,H_(2)O_(2)损伤组,细胞死亡率显著提高[(23.3±1.14)%vs.(12.81±0.71)%,P<0.001];与H_(2)O_(2)组相比,H_(2)O_(2)损伤+APS修复组黄芪多糖组能够显著降低过氧化氢引起的细胞死亡[(16.93±0.64)%vs.(23.3±1.14)%,P<0.001]、提高细胞生存率[(65.77±5.08)%vs.(39.95±4.90)%,P<0.05)]、减轻细胞凋亡[(18.90±1.14)%vs.(4.80±0.39)%,P<0.001]。黄芪多糖处理后,irisin及其上游调控因子PGC-1α的信使核糖核酸(mRNA)转录水平和蛋白表达量均明显提高,差异具有统计学意义(P<0.05)。结论黄芪多糖对心肌细胞的保护作用至少部分是通过PGC-1α/irisin信号通路实现。

Objective This study explores the effect and mechanism of Astragalus polysaccharide in hydrogen peroxide-induced cardiomyocyte injury.Methods H9C2 cells were divided into four groups:①control,②control+APS group,③H_(2)O_(2) injury,④H_(2)O_(2)+APS group.LDH leakage assay,MTT assay,immunofluorescence staining,TUNEL,RT-PCR,and western blot were employed to evaluate the effects of astragalus polysaccharides on cardiomyocyte apoptosis and death caused by hydrogen peroxide.PCR and western blot also examined PGC-1αand irisin expression.Results Compared with the control group,the cell death rate after H_(2)O_(2) admission increased from[(12.81±0.71)%vs.(23.3±1.14)%,P<0.001].Astragalus polysaccharides could significantly reduce cell death caused by hydrogen peroxide[(16.93±0.64)%vs.(23.3±1.14)%,P<0.001],improve cell survival rate[(65.77±5.08)%vs.(39.95±4.90)%,P<0.05],and inhibit cell apoptosis[(18.90±1.14)%vs.(4.80±0.39)%,P<0.001].In addition,the mRNA and expression of irisin and its upstream regulator PGC-1αincreased remarkably after astragalus polysaccharide treatment(P<0.05).Conclusion The protective effect of astragalus polysaccharides on cardiomyocytes is at least partly mediated by PGC-1α/Irisin signal path activation.