薯蓣皂素对缺氧诱导的H9c2大鼠心肌细胞内质网应激损伤的保护作用

The protective effects of diosgenin on hypoxia-induced endoplasmic reticulum stress injury of rat myocardial cell H9c2

目的探究薯蓣皂素(Diosgenin, DG)对缺氧诱导的大鼠心肌细胞H9c2损伤及心肌缺血再灌注(Mycardial ischemia reperfusion, MI/R)模型大鼠的保护作用及作用机制。方法将细胞分为H9c2组、低氧诱导(Hypoxia)组、DG (10mg/L)、DG (20 mg/L)和DG (50 mg/L)组,缺氧诱导细胞损伤,并给予对应浓度的DG或溶媒处理,CCK8检测细胞增殖,流式检测细胞凋亡,Western blot检测C/EBP环磷酸腺苷反应元件结合转录因子同源蛋白(CCAAT/enhancer-binding protein (C/EBP) homologous protein,CHOP)、Caspase-12、DNA损伤诱导蛋白(Growth arrest and DNA damage-inducible protein 34, GADD34)和免疫球蛋白重链结合蛋白(Immunoglobulin heavy-chain-binding protein, Bip)的表达,试剂盒检测上清液超氧化物歧化酶(Superoxide dismutase, SOD)和丙二醛(Malondialdehyde, MDA)浓度。复制大鼠MI/R模型,灌胃给予大鼠DG,检测大鼠心率和平均动脉压(Mean artery pressure, MAP)。检测大鼠血清肌酸激酶(creatine kinase, CK)、SOD和MDA浓度,HE染色检测组织损伤,Western blot检测内质网应激相关蛋白表达。结果与H9c2组比较,Hypoxia组细胞增殖速度显著降低,细胞凋亡率明显升高;与Hypoxia组比较,DG (10, 20, 50 mg/L)组细胞增殖速度明显升高,细胞凋亡率明显降低;同时,DG (10, 20, 50 mg/L)能显著减弱Hypoxia对CHOP、Caspase-12表达的诱导作用和对GADD34和BiP表达的抑制作用。此外,缺氧能显著升高上清液MDA浓度,降低SOD浓度;DG能明显减弱缺氧的作用。DG还能显著升高MI/R模型大鼠心肌功能,减轻心肌组织损伤,降低心肌组织CHOP和Caspase-12的表达,诱导GADD34和BiP的表达,降低血清MDA浓度,升高SOD浓度。结论 DG能通过抑制内质网应激减轻缺氧诱导的心肌细胞损伤及MI/R模型大鼠心肌组织损伤。

Objective To investigate the effects and mechanisms of diosgenin(DG)on hypoxiainduced injury of rat myocardial H9c2 cell.Methods Cells were divided into H9c2,DG,Hypoxia and Hypoxia+DG group.Cells were treated with hypoxia for inducing injury,and cells were treated with corresponding concentrations of DG or solvent.Cell proliferation was measured by CCK8 assay,apoptosis was determined by flow cytometry,the expressions of endoplasmic reticulum stress(ERS)-related proteins(CHOP,cleaved caspase-12,GADD34 and BiP)were determined by western blot.The concentrations of SOD and MDA were also measured.The MI/R rat model was produced,rats were treated with DG intragastrically,recorded heart rate(HR)and mean artery pressure(MAP).The concentrations of serum creatine kinase(CK),SOD and MDA were measured,the tissue injury was determined by HE staining,and the related proteins of ERS was measured by Western blot.Results Compared with H9c2 group,the proliferation rate was downregulated and apoptosis rate was increased in Hypoxia group;compared with the Hypoxia group,proliferation rate was up-regulated and apoptosis rate was decreased in Hypoxia+DG group.Meanwhile,the expression levels of CHOP and Caspase-12 in Hypoxia group were increased compared with the H9c2 group,but the expression levels of GADD34 and BiP were decreased.In addition,hypoxia decreased the concentration of MDA,but increased SOD significantly.DG alleviated the effects of hypoxia.Furthermore,DG enhanced cardiac function of model rats of MI/R,alleviated the injury of myocardial tissue,inhibited the expressions of CHOP and Caspase-12,induced the expressions of GADD34 and BiP,down-regulated the concentration of MDA,and increased SOD in serum of rats.Conclusion DG attenuates hypocia-induced myocardial cell injury and myocardial injury of model rats of MI/R through inhibiting ERS.