Exendin-4对大鼠皮质神经元缺血再灌注损伤后内质网相关性细胞凋亡的影响

目的探讨Exendin-4(Ex-4)对大鼠脑缺血再灌注损伤的保护作用及机制。方法体外培养Spra-gue Dawley(SD)乳鼠皮质神经元并随机分为对照组(正常培养)、模型组(体外模拟缺血再灌注)、治疗组(建模前2h、建模中均给予Ex-4)。免疫荧光染色鉴定神经元纯度,RT-PCR检测GLP-1受体基因表达,ELISA检测神经元细胞浆内cAMP水平,MTT法测定神经元存活率,流式细胞术检测神经元凋亡率,Western-blot免疫印迹法检测葡萄糖调节蛋白78(GRP78)、C/EBP同源蛋白(CHOP)表达。结果大鼠皮质神经元可体外纯化培养。RT-PCR及ELISA检测结果显示皮质神经元存在活性GLP-1受体。体外模拟缺血再灌注后神经元凋亡率明显增加,早期凋亡率及总凋亡率分别为(22.43±1.67)%、(41.87±3.2)%,Ex-4(0.4μg/ml)干预后神经元凋亡率明显下降,早期凋亡率及总凋亡率分别降至(7.53±0.6)%、(13.67±1.77)%,两组比较差异均有统计学意义(t早期凋亡率=14.511、t总凋亡率=13.352,P0.01)。体外模拟缺血再灌注损伤可诱导神经元GRP78、CHOP表达上调,Ex-4干预后神经元GRP78表达进一步增加、CHOP表达反而减少,两组GRP78、CHOP含量比较差异均有统计学意义(tGRP78(%control)=7.103、tCHOP(%control)=7.816,P0.01)。结论 Ex-4对大鼠皮质神经元体外模拟缺血再灌注损伤具有保护作用,其可能机制为抑制损伤后内质网相关性细胞凋亡。

Effect of Exendin-4 on ER-related apoptosis of rat cortical neurons induced by ischemia/reperfusion injury in vitro

Objective To explore the effect of Exendin-4 on apoptotic induction of simulated ischemia/reperfusion in primary rat cortical neurons.Methods Rat cortica1 neurons were cultured in vitro,identified by NSE-immunohistologica1 staining and immunofluorescence staining,and randomly divided into groups as follows:Control group,I/R group and Ex-4 group.Active GLP-1R was established by RT-PCR and ELISA.Apoptotic rates were determined by flow cytometry assay.Immunoblotting was adopted for examining protein levels of ...