Nrf2/HO-1在远隔缺血后处理减轻大鼠心肺复苏脑损伤中的作用

Effect of Nrf2/HO-1 in remote ischemic post-conditioning alleviating rat brain injury induced by cardiopulmonary resuscitation

目的探讨核因子E2相关因子2(Nrf2)/血红素氧化酶-1 (HO-1)在远隔缺血后处理减轻大鼠心肺复苏脑损伤过程中的表达变化及意义。方法采用随机数字表法将45只成年雄性SD大鼠分为3组:假手术组(Sham组)、模型组(Control组)、远隔缺血后处理组(RIPost组),每组15只。Control组大鼠建立窒息性心肺复苏脑损伤模型,RIPost组大鼠在自主循环恢复后行肢体远隔缺血后处理。在自主循环恢复后24 h分别采用苏木精-伊红染色、酶联免疫吸附试验检测血清神经元特异性烯醇化酶(NSE),观察脑组织的损伤情况; Western Blotting、免疫组织化学染色、实时荧光定量PCR检测脑组织Nrf2、HO-1蛋白及其mRNA表达情况。结果与Sham组相比,Control组呈急性缺血性改变,海马区神经元有明显的损伤,血清NSE含量显著升高,差异有统计学意义(P <0. 05),而RIPost组病理学改变轻于Control组,血清NSE含量也较Control组明显降低,差异有统计学意义(P <0. 05);Control组、RIPost组的Nrf2核蛋白和HO-1蛋白表达均高于Sham组,且RIPost组HO-1蛋白表达显著高于Control组,差异均有统计学意义(P值均小于0. 05)。实时荧光定量PCR显示Control组及RIPost组Nrf2 mRNA表达水平差异无统计学意义(P> 0. 05); RIPost组HO-1 mRNA的表达较Control组升高更显著,差异有统计学意义(P <0. 05)。结论远隔缺血后处理可减轻大鼠心肺复苏脑损伤,其作用机制可能与上调大鼠Nrf2/HO-1通路有关。

Objective To investigate the expression alternation and the effect of nuclear factor erythroid 2-related factor 2(Nrf2)and heme oxygenase-1(HO-1)in rats with remote ischemic post-conditioning alleviating brain injury induced by cardiopulmonary resuscitation.Methods According to the random number table method,a total of 45 adult male SD rats were divided in to Sham-operation group(Sham group),asphyxial cardiac arrest resuscitation group(Control group)and remote ischemic post-conditioning group(RIPost group),with 15 cases in each group.The rats in Control group were induced by 8-min asphyxiation and resuscitated with a standardized method,The remote ischemic post-conditioning models were established in RIPost group on the basis of the Control group.At the 24th hour after return of spontaneous circulation,pathomorphological changes in brain tissues were detected by hematoxylin-eosin staining,and the contents of neuron specific enolase(NSE)in serum were assessed by enzyme linked immunosorbent assay,the protein and mRNA expression of Nrf2,HO-1 in brain tissues were detected by Western blotting,immunohistochemistry and real-time(RT)PCR.Results Compared with Sham group,acute ischemic changes were found in Control group,which hippocampal neurons were obviously damaged,and NSE concentration in serum was increased significantly(P<0.05);while the pathological changes and serum NSE concentration in RIPost group were milder than those in Control group(P<0.05);the protein expressions of nuclear Nrf2 and HO-1 in Control group and RIPost group were higher than those in Sham group,and the expressions in RIPost group were higher than those in Control group(with P values below 0.05).In addition,RT-PCR analysis showed that there were no significant differences in Nrf2 mRNA levels in Control group and RIPost group(P>0.05),but HO-1 mRNA expression in RIPost group was significantly higher than that in Control group(P<0.05).Conclusion Remote ischemia post-conditioning can relieve brain injury induced by cardiopulmonary resuscitation,and the neuroprotective mechanism of RIPost may be related with the Nrf2/HO-1 signaling pathway.