ERK1/2和PI3-K通路在蛛网膜下腔出血大鼠海马区对神经细胞自噬的调控作用

Effects of ERK1/2 and PI3-K pathways on the regulation of autophagy in the hippocampus of rats with subarachnoid hemorrhage

目的:探讨细胞外信号调节激酶(extracellular regulated protein kinases,ERK1/2)和磷脂酰肌醇3-激酶(phosphatidylinositol 3-kinase,PI3-K)通路对大鼠蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后神经细胞自噬的调控作用。方法:雄性SD大鼠160只,分为假手术(Sham)组、模型(SAH)组、ERK1/2抑制剂U0126组和PI3-K抑制剂LY294002组。采用二次注血法制作SAH大鼠模型,HE染色观察海马区神经细胞的形态变化;免疫组织化学染色法检测海马区磷酸化ERK1/2、PI3-K、自噬相关蛋白Beclin-1和微管相关蛋白1轻链(LC3)-II的表达实时荧光定量PCR检测海马区ERK1/2、PI3-K、自噬相关蛋白Beclin-1和微管相关蛋白LC3的表达。结果:SAH组海马区神经细胞存活率低于Sham组,ERK1/2、PI3-K、Beclin-1和LC3的表达水平高于Sham组(P<0.05);U0126组和LY294002组海马区神经细胞存活率均高于SAH组,ERK1/2、PI3-K、Beclin-1和LC3表达均低于SAH组(P<0.05);U0126组和LY294002组两组间海马区神经细胞存活率差异无统计学意义(P>0.05),U0126组ERK1/2、Beclin-1和LC3表达水平低于LY294002组(P<0.05),PI3-K表达水平高于LY294002组(P<0.05)。结论:ERK1/2和PI3-K通路激活共同参与SAH后神经细胞自噬的调节,且以PI3-K通路更为主要。

Objective：To investigate the effect of extracellular regulated protein kinases （ERK1/2） and phosphatidylinositol 3-kinase （PI3-K） pathways on the regulation of autophagy in the hippocampus of rats with subarachnoid hemorrhage.Methods：Totally 160 male SD rats were divided into sham operated group,SAH group,inhibitor U0126 group,inhibitor LY294002 group.The animal models were established by injecting the autologous blood into cisterna magna twice.The animal models were established by injecting the autologous blood into cisterna magna twice.The neuronal morphological changes in hippocampus of rats were detected with HE staining;The expression of phosphorylated ERK1/2,PI3-K,Beclin-1 and LC3-Ⅱ in hippocampus of rat were detected with immunohistochemistry.The expression of ERK1/2、PI3-K.Beclin-1 and LC3 in hippocampus of rat were detecteel with RT-PCR.Results：The survival rate of neurons in SAH group was lower than sham group,and expression of ERK1/2,PI3-K,Beclin-1 and LC3 was higher than sham group （P 〈0.05）.The survival rate of neurons in hippocampus of U0126 group and LY294002 group was higher than SAH group.The expression of ERK1/2,PI3-K,Beclin-1 and LC3 was lower than SAH group （P 〈0.05）.The difference of survival rate of neurons between U0126 group and LY294002 group was not statistically significant （P 〉 0.05）.The expression of ERK1/2,Beclin-1 and LC3 in U0126 group was lower than LY294002 group （P 〈0.05）.The expression of PI3-K was higher than LY294002 group （P 〈 0.05）.Conclusion：The both activation of ERK1/2 and PI3-K pathway is involved in the regulation of autophagy of neural cells after SAH,and the PI3-K pathway is more important.