miR-17-5p对缺血性脑卒中大鼠的神经保护作用及其对细胞外调节蛋白激酶1/2信号通路的影响

Neuroprotective effect of miR-17-5p on rats with ischemic stroke and its influence on extracellular regulatory protein kinase 1/2 signal pathway

目的:观察miR-17-5p对缺血性脑卒中大鼠的神经保护作用及其对胞外调节蛋白激酶1/2(ERK1/2)信号通路的影响。方法:将大鼠随机数字法分为模型组、miR-17-5p mimics组、miR-17-5p inhibitor组。建模后,模型组经尾静脉注射10 mL/kg生理盐水,miR-17-5p mimics组、miR-17-5p inhibitor组分别经尾静脉注射7μL miR-17-5p mimics、miR-17-5p inhibitor与RNAi脂质体转染试剂的混合溶液。各组大鼠苏醒后的24 h进行神经功能评分,测定脑梗死体积、大鼠脑组织含水量,检测缺血侧大脑皮质细胞凋亡率,caspase-3、Bax、Bcl-2和ERK1/2蛋白表达。结果:miR-17-5p mimics组的神经功能障碍评分、脑梗死体积、脑组织含水量、缺血侧大脑皮质细胞凋亡率明显低于模型组,miR-17-5p inhibitor组的神经功能障碍评分、脑梗死体积、脑组织含水量、缺血侧大脑皮质细胞凋亡率显著高于其他2组;miR-17-5p mimics组大鼠缺血脑组织中caspase-3、Bax蛋白表达明显低于模型组,Bcl-2、p-ERK1/2蛋白表达高于模型组;miR-17-5p inhibitor组大鼠缺血脑组织中caspase-3、Bax、p-ERK1/2蛋白表达显著高于其他2组,Bcl-2蛋白表达低于其他2组。结论:miR-17-5p对缺血性脑卒中大鼠的脑损伤具有一定的保护作用,miR-17-5p可抑制ERK1/2信号通路激活。

Objective:To observe the neuroprotective effect of miR-17-5p on ischemic stroke rats and its influence on the extracellular regulatory protein kinase 1/2(ERK1/2)signaling pathway.Methods:Sixty-nine rats were randomly divided into three groups,the model group,the miR-17-5p mimics group,and the miR-17-5p inhibitor group,with 23 rats in each group.After modeling,the model group was injected with 10 ml/kg saline,the miR-17-5p mimics group was injected with 7μL miR-17-5p mimics mixed solution via the tail vein,and the miR-17-5p inhibitor group was injected with 7μL miR-17-5p inhibitor’s mixed solution via the tail vein.The rats in each group were evaluated for neurological function 24 hours after awakening,the cerebral infarction volume,and the water content of rat brain tissue were measured,the apoptosis rate of cerebral cortex of the ischemic side,caspase-3,Bax,Bcl-2 and ERK1/2 protein were measured.Results:The neurological dysfunction score,cerebral infarction volume,brain tissue water content,and apoptosis rate of ischemic cortical cells in the miR-17-5p mimics group were significantly lower than those in the model group.The neurological dysfunction score,cerebral infarction volume,brain tissue water content,and apoptosis rate of ischemic cortical cells in the miR-17-5p inhibitor group were significantly higher than those in the other two groups.The expression of caspase-3 and Bax protein in the ischemic brain tissue of miR-17-5p mimics group was significantly lower than that in the model group,while the expression of Bcl-2 and p-ERK1/2 protein was higher than that of the model group.The expression of caspase-3,Bax,and p-ERK1/2 proteins in the ischemic brain tissue of miR-17-5p inhibitor group rats was significantly higher than that of the other two groups,while the expression of Bcl-2 protein was lower than that of the other two groups.Conclusion:miR-17-5p has a certain protective effect on brain injury in ischemic stroke rats,and miR-17-5p can inhibit the activation of ERK1/2 signaling pathway.