PEP-1-SOD1对离体缺血再灌注损伤大鼠心肌Bax、Bcl-2蛋白表达的影响

Effects of PEP-1-SOD1 on Expression of Bax,Bcl-2 of Myocardium in Rats Induced with Ischemia-Reperfusion Injury ex vivo

目的:研究细胞穿透肽PEP-1介导人铜锌-超氧化物歧化酶(Cu,Zn-SOD,SOD1)对大鼠离体心肌缺血再灌注损伤(MIRI)细胞凋亡的影响。方法:采用Langendorff灌流系统对离体大鼠心脏进行停灌-复灌建立心肌缺血再灌注损伤模型。大鼠随机分为对照组、SOD1蛋白预处理组,25、50、100μmol/L PEP-1-SOD1蛋白预处理组。复灌结束后,TUNEL法检测心肌细胞凋亡,免疫荧光法检测心肌组织Bax、Bcl-2蛋白表达。结果:与对照组及SOD1组相比,各PEP-1-SOD1组心肌细胞凋亡指数(AI)显著下降,Bcl-2蛋白表达升高,Bax蛋白表达显著减少(P<0.01)。结论:PEP-1-SOD1融合蛋白可抑制离体心脏缺血再灌注损伤大鼠心肌细胞凋亡,其机制可能与上调Bax表达及下调Bcl-2表达有关。

Objective To investigate the effects of PEP-1 mediated human Cu,Zn superoxide dismutase on the myocardium apoptosis induced by ischemia-reperfusion injury(IRI) in rats ex vivo.Methods The MIRI rats model were prepared with Langendorff perfusion system ex vivo.The model rats were randomly divided into control group,SOD1 pretreated group,PEP-1-SOD1 pretreated with 25,50,100 μmol/L groups.The myocardium apoptosis and expression of Bax,Bcl-2 were determined with TUNEL method and immunofluorescencein method after reperfusion.Results Compared with control and SOD1 groups,the apoptosis indexes(AI) were significantly decreased,the expression of Bcl-2 were upregulated,the expression of Bax were downregulated in all PEP-1-SOD1 groups(all P0.01).Conclusion The fusion protein PEP-1-SOD1 could inhibit the apoptosis of myocardium in MIRI rats,which may be related to its upregulation of Bax expression and downregulation of Bcl-2 expression.