电针对脑缺血再灌注损伤大鼠海马半胱氨酸天冬氨酸蛋白酶-3表达的影响

Effect of electroacupuncture on expression of hippocampal Caspase-3 in rats with cerebral ischemia/reperfusion injury

目的:观察电针对脑缺血再灌注损伤大鼠海马半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)表达的影响,探讨电针抗脑缺血再灌注损伤后细胞凋亡的作用机制。方法:雄性SD大鼠随机分为假手术组、模型组、电针组及抑制剂组,每组20只。除假手术组外,其他各组大鼠采用改良的Longa线栓法建立局灶性脑缺血再灌注损伤模型。造模成功后,电针组大鼠于患侧“合谷”“尺泽”“足三里”“三阴交”给予电针干预1次,20 min;抑制剂组于造模前30 min经侧脑室注入Caspase-3抑制剂Z-DEVD-FMK。观察各组大鼠神经功能缺损评分的变化,用TTC染色法观察病灶侧脑梗死情况,TUNEL染色法检测海马CA1区细胞凋亡指数,Western blot法检测海马Caspase-3蛋白表达,荧光定量PCR法检测海马Caspase-3 mRNA表达。结果:与假手术组比较,模型组大鼠神经功能缺损评分、脑梗死体积百分比、海马CA1区细胞凋亡指数、海马Caspase-3蛋白及mRNA表达水平均明显升高(P<0.01)。与模型组比较,电针组、抑制剂组的神经功能缺损评分、脑梗死体积百分比、海马CA1区细胞凋亡指数、海马Caspase-3蛋白及mRNA表达水平均下降(P<0.05)。结论:电针能对脑缺血再灌注损伤产生保护作用,其调控机制之一可能是电针刺激通过抑制Caspase-3表达,发挥其抗细胞凋亡作用,进而达到其抗脑缺血再灌注损伤的作用。

Objective To observe the effect of electroacupuncture(EA)on the expression level of Caspase-3,so as to explore its mechanism in inhibiting apoptosis after cerebral ischemia reperfusion.Methods SD male rats were randomly divided into sham-operation,model,EA and Caspase-3 inhibitor groups(n=20 rats in each group).The focal cerebral ischemia/reperfusion injury rat model was established by occlusion of the middle cerebral artery.Rats of the EA group received EA at“Hegu”(LI4),“Chize”(LU5),“Zusanli”(ST36)and“Sanyinjiao”(SP6)on the affected side for 20 min.Rats of the inhibitor group were given intracerebroventricular injection of inhibitor Z-DEVD-FMK 5μg before modeling.The neurological deficit scores(NDS)were assessed by using Longa’s method,the infarct size of the brain assessed after staining with 2%triphenyltetrazolium chloride.The apoptosis index of nerve cells were observed by TUNEL staining,PCR and Western blot were used to detect the mRNA and protein expressions of Caspase-3 in the hippocampus,separately.Results After modeling,the NDS,infarct volume,the apoptosis index of hippocampus CA1 area,and Caspase-3 mRNA and protein expression levels were significantly increased in the model group compared with the sham-operation group(P<0.01).After intervention,the NDS,infarct volume,the apoptosis index,Caspase-3 mRNA and protein expression levels were all significantly decreased in the EA and Caspase-3 inhibitor groups re-levant to the model group(P<0.05).Conclusion EA can improve the neurological function in cerebral ischemia/reperfusion rats,which may be related to its effect in inhibiting of Caspase-3 expression.