电针对局灶性脑缺血再灌注大鼠皮质Slit-Robo三磷酸鸟苷酶激活蛋白-1和细胞分裂周期蛋白42表达的影响

目的:观察电针对大脑中动脉闭塞(MCAO)模型大鼠皮质Slit-Robo三磷酸鸟苷酶激活蛋白-1(Slit-Robo GTPase-activating protein-1,srGAP 1)和细胞分裂周期蛋白42(cell division-cycle 42,Cdc 42)表达的影响,探讨srGAP 1和Cdc 42在电针治疗MCAO后神经恢复中的作用。方法:雄性SD大鼠随机分为正常组、模型组、非经穴组和电针组,每组12只。利用改进的Longa法复制MCAO模型。电针组取"曲池""足三里"穴,非经穴组取手足阳明经与少阳经之间非经穴处,每日1次,每次30min,共14d。分别在术后1、3、7、14d时间点对各组大鼠进行神经功能评分(mNSS),并利用免疫荧光法检测缺血侧大脑皮质中srGAP 1和Cdc 42的荧光强度及分布,用免疫印迹(Western blot)法检测大鼠梗死区周围大脑皮质中srGAP1和Cdc 42蛋白表达。结果:神经功能评分显示,在术后7、14d时电针组较模型组、非经穴组同时间段的mNSS评分显著降低(P0.01)。免疫荧光检测结果显示,srGAP 1和Cdc 42主要在细胞质表达;模型组srGAP 1高于正常组(P0.01),而电针组显著低于模型组和非经穴组(P0.01);模型组Cdc 42显著低于正常组(P0.01),而电针组明显高于模型组和非经穴组(P0.01)。Western blot检测结果显示,模型组srGAP 1蛋白表达量较正常组明显升高(P0.01),电针组srGAP 1蛋白表达显著低于模型组及非经穴组(P0.01);模型组Cdc 42蛋白表达量与正常组的差异无统计学意义(P0.05),而电针组Cdc 42蛋白表达显著高于模型组和非经穴组(P0.01)。结论:局灶性脑缺血再灌注后大鼠脑损区周围皮质srGAP 1明显增高,而Cdc 42明显减少,这可能与srGAP 1使Cdc 42失活有关;电针治疗后srGAP 1显著下调,而Cdc42上调,可能是电针促进脑梗死后神经功能恢复的机制之一。

Effect of Electroacupuncture on Expression of Cortical srGAP 1 and Cdc 42 in Rats with Focal Cerebral Infarction

Objective To observe the effect of electroacupuncture(EA)intervention on the neurological function and the expression change of Slit-Robo GTPase-activating protein-1(srGAP 1)and cell division-cycle 42(Cdc 42)in the cortex of rats with cerebral ischemic injury(CIRI),so as to explore the mechanism of EA in the management of cerebral infarction.Methods A total of 48 male Sprague Dawley(SD)rats were randomly and equally divided into control,model,non-acupoint EA and EA groups(n=12/group).The CIRI model was established based on the modified Zea Longa method.EA intervention was applied for 30 min,once a day for 14 days.Modified neurologic severity scores(mNSS)were assessed on day 1,3,7and 14 after modeling.Immunofluorescence assay was used to detect the immunoactivity and distribution of srGAP 1and Cdc 42 in the cortical ischemic region.Western blot was employed to detect the expression of srGAP 1and Cdc 42 in the affected cortex.Results The mNSS displayed that the neurological score in the EA group was significantly lower than that in the model group and non-acupoint EA group at the 7th d and 14 th d(P<0.01).Immunofluorescence results showed that cerebral srGAP 1and Cdc 42 were expressed mainly in the cytoplasm.The fluorescence intensity of srGAP 1of the EA group was significantly lower than that of the model group and non-acupoint EA group(P<0.01).Meanwhile the fluorescence intensity of Cdc 42 of the EA group was markedly higher than that in the model group and non-acupoint EA group(P<0.01).Western blot assay indicated that the expression level of srGAP 1in the model group was significantly higher than that of the control group(P<0.01),and that of the EA group was much lower than those of the model group and non-acupoint EA group(P<0.01).There was no significant difference of srGAP 1expression levels between the non-acupoint EA group and the model group(P>0.05).Additionally,the protein expression of Cdc 42 in the model group was slightly higher than that of the control group(P>0.05),and that of the EA group was significantly higher than those of the model group and non-acupoint EA group(P<0.01).There was no significant difference of Cdc 42 expression levels between the non-acupoint EA group and the model group(P>0.05).Conclusion Cerebral infarction induced increase of cerebral srGAP 1and decrease of Cdc 42 can be reversed by acupoint EA intervention in CIRI rats,which may be responsible for its effect in improving impaired neurological function after cerebral infarction.