细胞外信号调节激酶1/2与Rho激酶作用对脑梗死后神经血管单元的影响

Regulatory effect of interaction between extracellular signal-regulated kinase 1/2 and Rho-associated kinase on neurovascular unit after cerebral infarction

目的研究脑梗死后细胞外信号调节激酶1/2(ERK_(1/2))和Rho激酶(ROCK)两条信号通路通过相互作用激活下游效应分子多聚ADP核糖聚合酶-1(PARP-1)来调控脑梗死后神经血管单元。方法该实验分为两个部分:35只SD大鼠随机分为假手术组(s)和脑梗死组(M),脑梗死组根据脑梗死后时间不同又分为1h、3h、12h、24h、3d和7d六个亚组,分别采用westem blot检测假手术组及脑梗死组各亚组ERK_(1/2)、ROCK蛋白表达水平。35只SD大鼠随机分为对照组、模型组、U0126组、Fasudil组和U0126+Fasudil组,分别检测神经功能、脑梗死面积以及ROCK、ERK_(1/2)及PARP-1的蛋白表达水平。结果假手术组各个时间点总ERK_(1/2)/2和p-ERK_(1/2)表达相同。脑梗死组总ERK_(1/2)表达不变,p-ERK_(1/2)表达先降低后升高,24h时达最高峰。脑梗死组ROCK的表达随时问的延长逐渐升高,12h表达达高峰,随后表达下降。模型组与对照组相比,p-ERK_(1/2)、ROCK及PARP-1的表达显著提高(P<0.05);与模型组相比,Fasudil组p-ERK_(1/2)的表达下降(P<0.05),而U0126组ROCK表达无变化(p>0.05),Fasudil组、U0126组及Fasudil组+U0126组PARFP-1的表达显著下降(P<0.05),其中以U0126+Fasudil组下降最为显著。结论 ERK_(1/2)和ROCK都参与了脑梗死后脑组织的损伤,ERK_(1/2)可能作为ROCK的下游效应分子,与ROCK共同调节PARP-1的表达进而调控脑梗死后神经血管单元的存亡。

Objective To investigate the regulatory effect of interaction between extracellular signal-regulated kinase 1/2 （ERK1/2 ） and Rho-associated kinase （ROCK） on the neurovascular unit by activating poly （ ADP ribose） polymerase-1 （ PARP-1 ） after cerebral infarction. Methods Thirty-five Sprague-Dawley （SD） rats were randomly divided into sham-operation group and middle cerebral artery occlusion （MCAO） group. Each group was further divided into 1 hrs, 3 hrs, 12 hrs, 24 hrs, 3 days, and 7 days subgroups according to the time points when examination was performed after operation. The protein expression levels of ERK1/2 and ROCK were measured by Western blot. Another 35 SD rats were randomly divided into control group, model group, Fasudil group, U0126 group, and Fasudil ＋ U0126 group, and neurological function, infarct area, and the protein expression levels of ERKI/2, ROCK, and PARP- 1 were measured. Results For the shamoperation group, the expression of total ERK1/2 and phosphorylated ERK1/2 （ p-ERKI/2 ） remained unchanged over time. For the MCAO group, the expression of total ERK1/2 remained unchanged, while the expression of p- ERKI/2 first decreased, then increased, and reached the peak level at 24 hrs after operation. The ROCK expression of MCAO group gradually increased over time, reached the peak level at 12 hrs, and then fell. Compared with the control group, the model group had significantly increased expression of p-ERK1/2, ROCK, and PARP-1 （P 〈 0.05）. Compared with the model group, the Fasudil group had significantly reduced expression of p-ERK1/2 （ P 〈 0.05 ）, the U0126 group had unchanged expression of ROCK （ P 〉 0.05 ）, and the Fasudil group, U0126 group, and Fasudil ＋ U0126 group, especially Fasudil ＋ U0126 group, had significantly reduced expression of PARP-1 （ P 〈 0.05 ）. Conclusions Both ERK1/2 and ROCK are involved in the brain damage after cerebral infarction. ERKI/2, as a downstream effective molecule of ROCK, may regulate the expression of PARP-1 together with ROCK and thus adjust the survival of neurovascular unit after cerebral infarction.