缺血后处理对局灶脑缺血再灌注大鼠Toll样受体2表达的影响

目的 探讨缺血后处理对大鼠局灶性脑缺血再灌注时Toll样受体2(TLR2)表达的影响。方法 成年雄性SD大鼠90只,分为假手术组、缺血再灌注组、缺血后处理组各30只; 用线栓法建立局灶性大脑中动脉闭塞模型(MCAO),随机分为假手术组(sham)、缺血再灌注组(I/R)、缺血后处理组(IPC),分别于再灌注24、48、72 h后留取大脑皮质组织; 采用Longa的等级评分法进行神经行为学评分,免疫组化和蛋白质印记(Western blot)法检测TLR2蛋白的表达水平,逆转录-聚合酶链反应(RT-PCR)检测TLR2 mRNA表达水平。结果(1)缺血后处理组大鼠神经行为学评分明显改善;(2)缺血再灌注组TLR2蛋白在再灌注24、48、72 h表达水平明显升高(P<0.05); 缺血后处理组TLR2蛋白表达在各时间点均减少(P<0.05); TLR2 mRNA的表达趋势与蛋白表达基本一致。结论 缺血后处理可以降低TLR2表达水平,这可能是其脑保护作用的部分机制之一。

Effects of ischemic postconditioning on TLR2 expression in rats cerebral with ischemia/reperfusion injury

ObjectiveTo investigate the protective effect of ischemic postconditioning by examining the express of toll-like receptor 2(TLR2)in cerebral ischemic reperfusion injury(I/R).Methods SD rats model of focal ischemic reperfusion was induced by intraluminal middle cerebral artery occlusion(MCAO)with a nylon monofilament suture. Ischemic animals were randomly assigned to 3 groups: sham group(n=30), I/R group(n=30)and IPC group(n=30). Each group was divided into 3 subgroups by the different times after reperfusion(t=24 h, t=48 h, t=72 h).In IPC group, animals were further subjected to postconditioning(3 cycles of 30s ischemia and 30s reperfusion)after MCAO. Neurologic scores and infarct volumes were assessed at 24, 48 and 72 hours. TLR2 was examined by immunohistochemistry, Western blot and RT-PCR.Results IPC treatment improved neurologic scores and reduced infarct volumes compared with the I/R group. Compared with the sham group, the expression of TLR2 increased in the rats undergoing I/R procedure. The level of TLR2 significantly reduced in ischemic postconditioning group.Conclusions Ischemic postconditioning can reduce the expression of TLR2 which may be related to neuroprotective effects.