PI3K与ERK1/2信号传导通路在吡格列酮保护大鼠心肌缺血再灌注损伤中的作用机制

目的研究PI3K与ERK1/2信号传导通路在吡格列酮介导大鼠心肌缺血再灌注损伤中的作用机制。方法取一日龄Wistar大鼠乳鼠心室肌细胞进行体外培养,建立缺血再灌注损伤模型。分正常对照组(Co组)、缺血再灌注组(Ⅰ组)、Ⅰ组+吡格列酮预处理组(Pi组)、Pi组+PI3K特异性抑制剂LY294002组(Pi+LY组)。采用免疫细胞化学法检测细胞内ERK1/2、p-ERK1/2的分布与变化,Western-bloting检测细胞内p-ERK1/2蛋白表达水平变化。结果免疫细胞化学法结果显示各组ERK变化不大(P>0.05);免疫细胞化学法和Western-bloting结果显示Pi组p-ERK1/2的表达水平高于Ⅰ组(P<0.05),此变化被LY294002抑制(P<0.05);Ⅰ组p-ERK1/2的表达比Co组多,差异具有统计学意义(P<0.05)。结论吡格列酮通过PI3K/ERK1/2信号通路对大鼠心肌缺血再灌注损伤起保护性作用。

Research of the mechanism of pioglitazone on myocardial ischemic reperfusion in jury by PI3K and ERK1/2 signaling pathway

Objective To study the mechanism of pioglitazone on myocardial ischemic reperfusion injury by PI3K and ERK1/2 signaling pathway.Methods One day old Wistar rats＇ hearts were isolated and ventricular myocardium cells were separated by trypsin.The cells were collected and incubated in culture flasks.The model of ischemia reperfusion injury was established by 3 hours of hypoxia and 3 hour of reoxygenation subsequently.The cultured cardiomyocytes were randomly alloted to four groups which were normal control（Co）,ischemic reperfusion injury（Ⅰ）,Ⅰ＋pioglitazone（Pi） and Pi＋ LY294002（LY）.Immunocytochemical detected the distribution and change of ERK1/2 and p-ERK1/2.The levels of p-ERK1/2 protein were detected by Western-bloting.Results The expression levels of ERK1/2 were not changed in the four groups which were detected by Immunocytochemical（P〈0.05）.Immunocytochemical and Western-blotting showed that in Pi group the expression levels of p-ERK1/2 in the cultured cardiomyocytes were significantly increased than in I group.（P〈0.05）.However this change results from Pioglitazone were abolished by LY294002.Another,compared with Co group,I group had more p-ERK1/2 expression.（P〈0.05）.Conclusion Pioglitazone protects cardiomyocytes from I/R-induced apoptosis through PI3K/ERK1/2 signaling pathway.