京尼平对缺氧/复氧损伤后大鼠心肌细胞凋亡及自噬的影响

Effect of genipin on cardiomyocyte apoptosis and autophagy in rat after hypoxia/reoxygenation injury

目的探讨京尼平对缺氧/复氧(H/R)损伤后大鼠心肌细胞凋亡及自噬的影响。方法建立H/R损伤模型,体外培养的大鼠H9c2心肌细胞行缺氧12 h、复氧4 h。实验分为对照组(Con)、京尼平组(GE)、缺氧/复氧组(H/R)、缺氧/复氧+京尼平组(H/R+GE)。细胞计数试剂盒-8(CCK-8)检测细胞存活率,流式细胞仪检测细胞凋亡,透射电子显微镜观察自噬体,Western blotting检测Bax、Bcl-2、P62、Beclin1、LC3-Ⅱ、蛋白激酶B(Akt)、p-Akt、哺乳动物雷帕霉素靶蛋白(mTOR)和p-mTOR蛋白的表达。结果京尼平预处理增强了H/R损伤后的H9c2心肌细胞活力,抑制细胞凋亡及自噬体累积,降低自噬结构断面积与细胞质断面积的比值。Western blotting结果显示,京尼平预处理减少了H/R损伤后Bax、LC3-Ⅱ和Beclin1蛋白表达,增加Bcl-2、P62、p-Akt和p-mTOR蛋白表达。结论京尼平可以抑制H/R损伤后心肌细胞凋亡及自噬,其机制可能与上调Akt/mTOR信号通路有关。

Objective To investigate the effect of genipin on cardiomyocyte apoptosis and autophagy in rat after hypoxia/reoxygenation(H/R)injury.Methods The method with hypoxia treatment of H9c2 cells for 12 hours and then reoxygenation treatment for 4 hours was used in the present study in order to establish H/R model.The H9c2 cells were divided into control group(Con),genipin group(GE),model group(H/R),model+genipin group(H/R+GE).Cell viability was detected by cell counting kit-8(CCK-8).Cell apoptosis was determined by flow cytometry.Transmission electron microscopy was used to observe autophagosomes.The expression of Bax,Bcl-2,P62,Beclin1,LC3-Ⅱ,protein kinase B(Akt),p-Akt,mammalian target of rapamycin(mTOR),p-mTOR proteins were assessed by Western blotting.Results Genipin pretreatment enhanced the cell viability,prevented cell apoptosis and autophagosome accumulation,and reduced the ratio of the cross-sectional areas of the autophagic structures to that of the cytoplasm after H/R injury in H9c2 cells.Western blotting showed that genipin pretreatment decreased the expression of Bax,LC3-Ⅱ,Beclin1 proteins and increased the expression of Bcl-2,p62,p-Akt,p-mTOR proteins after H/R injury.Conclusion Genipin can inhibit H/R injury-induced apoptosis and autophagy,which may be through activating Akt/mTOR signaling pathway.