SP600125对大鼠肺缺血/再灌注损伤的保护作用及机制

目的:探讨SP600125-c-Jun氨基末端激酶(JNK)特异性抑制剂对大鼠肺缺血/再灌注损伤的保护作用及机制。方法:复制在体大鼠原位单肺缺血/再灌注模型,随机分3组(n=10):假手术对照组(Control组)、缺血再灌注组(I/R组)与缺血再灌注+SP600125干预组(SP600125组)。实验结束时取肺组织测湿/干重比(W/D)、肺泡损伤率(IAR);采用蛋白印迹法检测肺组织磷酸化JNK(p-JNK)、JNK蛋白的表达;免疫组化法检测肺组织Bcl-2、Bax、Caspase-3蛋白的表达;原位末端标记法检测肺组织细胞凋亡指数(AI);电镜观察肺组织超微结构的改变。结果:SP600125组肺组织p-JNK、Bax、caspase-3的蛋白表达显著低于I/R组(均P<0.01),Bcl-2的蛋白表达及Bcl-2/Bax的比值显著高于I/R组(均P<0.01),AI、W/D及IAR显著低于I/R组(均P<0.01),肺组织超微结构损伤不同程度减轻。结论:SP600125可能通过抑制JNK信号通路,上调Bcl-2/Bax的比值减少caspase-3依赖性的肺细胞凋亡,从而减轻肺缺血/再灌注损伤。

Protective effects and mechanism of SP600125 on lung ischemia/reperfusion injury in rats

Objective: To investigate the protective effects and mechanism of SP600125-specificity inhibitor of c-Jun N-terminal kinase(JNK)on lung ischemia /reperfusion injury in rats.Methods: The unilateral lung ischemia/reperfusion model was replicated in vivo.Rats were randomly divided into three groups(n=10): control group,ischemia/reperfusion group(I/R group) and ischemia/reperfusion + SP600125 group(SP600125 group).The lung tissues sampled at the end of each experiment were assayed for wet/dry weight ratio(W/D),the injured alveoli rate(IAR),the expression of phosphorylation JNK(p-JNK) and JNK protein were detected by Western blot,the expression of Bcl-2,Bax,Caspase3 protein were detected by immunocytochemistry techniques,the pneumocyte apoptosis index(AI) was detected by terminal deoxynucleotidy1 transferase mediated dUTP nick end abeling(TUNEL),the ultrastructure changes were observed under electron microscope.Results: Compared to I/R group,the expression of p-JNK,Bcl-2,Bax and caspase-3 protein were markedly decreased(all P<0.01),the expression of Bcl-2 protein and the ratio of Bcl-2/Bax were markedly increased in SP600125 group(all P<0.01).The value of AI,W/D,IAR showed significantly lower than those in I/R group(all P<0.01).Meanwhile,light morphological and ultrastructure injury were found in SP600125 group.Conclusion: SP600125 can suppress JNK signal pathway,up-regulate the ratio of Bcl-2/Bax to inhibit Caspase-3 dependent apoptosis,so that it protects lung tissue from ischemia/reperfusion injury.