电针对急性脊髓损伤大鼠运动功能及钙蛋白酶表达的影响

Effects of electroacupuncture on motor function and calpain expression in rats with acute spinal cord injury

目的:观察电针对脊髓损伤大鼠运动功能及钙蛋白酶表达的影响,探讨电针改善急性脊髓损伤的机制。方法:将30只雄性SD大鼠随机分为假手术组、模型组和电针组,每组10只。脊髓打击器打击大鼠胸10节段脊髓制备急性脊髓损伤模型。电针组造模后给予督脉穴("脊中"和"命门")电针治疗,每次30 min,1次/d,共治疗28 d。采用Basso Beattie Bresnahan(BBB)评分法对大鼠后肢运动功能进行评估;尼氏染色法观察脊髓组织病理变化;荧光定量PCR法检测脊髓组织中钙蛋白酶calpain1、calpain2及钙蛋白酶抑制蛋白(calpastatin)mRNA表达水平;Western blot法检测脊髓组织中calpain1、calpain2及calpastatin蛋白表达水平。结果:造模后,模型组大鼠BBB评分明显低于假手术组(P<0.01),治疗14、28 d时,电针组BBB评分明显高于模型组(P<0.01)。与假手术组比较,模型组脊髓损伤处的神经元数量减少,尼氏体染色细胞减少,甚至消失,而电针组大鼠脊髓神经元形态、尼氏体染色细胞数均优于模型组。与假手术组比较,模型组大鼠脊髓calpain1 mRNA和蛋白表达水平明显升高(P<0.01),calpastatin mRNA和蛋白表达水平明显降低(P<0.01);与模型组比较,电针组脊髓calpain1 mRNA和蛋白表达水平明显降低(P<0.01),calpastatin mRNA和蛋白表达水平明显升高(P<0.01);各组calpain2 mRNA和蛋白表达差异无统计学意义(P>0.05)。结论:电针可改善脊髓损伤大鼠的运动功能,该作用可能与抑制损伤脊髓组织中calpain1活性有关。

Objective To observe the effect of electroacupuncture(EA)on motor function,calpain and calpastatin expression in rats with spinal cord injury,so as to explore the mechanism of EA underlying improvement of acute spinal cord injury.Methods Thirty male SD rats were randomly divided into sham operation group,model group and EA group,with 10 rats in each group.The acute moderate spinal cord injury model was established by using a NYU spinal cord impactor.EA was applied to"Jizhong"(GV6)and"Mingmen"(GV4)for 30 min,once daily for 28 d.The Basso,Beattie and Bresnahan(BBB)rating scale(0 to 21 points)was used to assess changes of locomotor function.Histopathological changes of the injured spinal cord were observed after sectioning and Nissl staining,and the expression levels of calpain1,calpain2 and calpastatin mRNA and protein in the spinal cord tissues were detected by using quantitative real-time PCR and Western blot,respectively.Results The BBB score of the model group was significantly lower than that of the sham operation group(P<0.01),and was significantly higher in the EA group than that of the model group on 14th and 28th day(P<0.01).Compared with the sham operation group,the number of neurons in the model group decreased,and Nissl body stained cells decreased or even disappeared,which was evidently milder in the EA group.Compared with the sham operation group,the expression levels of calpain1 mRNA and protein in the spinal cord of the model group were significantly increased(P<0.01),while the expression levels of calpastatin mRNA and protein were significantly reduced(P<0.01).Following EA intervention,in contrast to the model group,the expression levels of calpain1 mRNA and protein in the EA group were significant down-regulated(P<0.01),calpastatin mRNA and protein expression levels were significantly up-regulated(P<0.01).There was no significant difference in calpain2 mRNA and protein expression among the 3 groups(P>0.05).Conclusion EA can improve the locomotor function of rats with spinal cord injury,which may be related to its effect in inhibiting the activity of calpain in the injured spinal cord.