电针对失坐骨神经大鼠腓肠肌细胞凋亡及相关蛋白的影响

摘要

目的:观察电针疗法对失坐骨神经大鼠腓肠肌细胞凋亡及相关蛋白的影响,探讨电针对失坐骨神经骨骼肌萎缩的延缓效应及其可能机制.方法:SD大鼠随机分为假手术组、模型组和电针组,每组21只.采用切断坐骨神经法制备腓肠肌萎缩大鼠模型.电针组电针患侧"足三里""承山"穴,每日1次,每次10 min,各组分别在术后7、14、21 d取材.TUNEL法检测腓肠肌细胞凋亡, Western blot法检测Bcl-2、Bcl-2相关的X蛋白(Bax)、细胞色素C(Cyt-C)以及天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)的蛋白表达,RT-PCR法检测腓肠肌Caspase-3 mRNA表达.结果:模型组各时点细胞凋亡指数均高于假手术组(P<0.05),电针组的细胞凋亡指数显著低于模型组(P<0.05).模型组各时点腓肠肌Bcl-2蛋白表达较假手术组显著降低(P<0.05),Bax、Cyt-C以及Caspase-3蛋白表达均明显升高(P<0.05).术后14、21 d,电针组与模型组比较,Bcl-2蛋白表达显著升高(P<0.05),Bax、Cyt-C及Caspase-3蛋白表达则明显降低(P<0.05).各组大鼠腓肠肌的Caspase-3 mRNA表达与蛋白表达结果基本一致.结论:电针能够促进腓肠肌Bcl-2的表达并抑制Bax、Cyt-C 和 Caspase-3的表达,从而抑制肌细胞的凋亡,这可能是电针延缓失神经性骨骼肌萎缩的机制之一.%Objective To observe the anti-apoptosis effect of electroacupuncture (EA) on gastrocnemius muscle cells in rats with denervated sciatic nerve, so as to explore its possible mechanisms underlying delaying atrophy of skeletal muscle.Methods Sixty-three male Sprague-Dawley rats were randomly divided into sham operation group, model group, and EA group, and then further divided into 3 subgroups in each group(n=7/subgroup).Gastrocnemius muscle atrophy model was established by transecting the sciatic nerve of rat.EA (5 Hz, 1.5 mA) was applied to "Zusanli" (ST 36) and "Chengshan" (BL 57) acupoints at the affected side for 10 min, once a day for 1, 2, 3 weeks, respectively.The gastrocnemius muscles were sampled on the 7th, 14th, 21th d after modeling, separately.The apoptotic cells were detected by TUNEL staining.Bcl-2, Bax, Cyt-C and Caspase-3 protein expressions were determined by Western blot.RT-PCR was used to check Caspase-3 gene expression.Results Compared with the sham operation group, the cell apoptotic index in gastrocnemius was markedly higher, gastrocnemius Bcl-2 protein expression was markedly down-regulated, and gastrocnemius Bax, Cyt-C and Caspase-3 protein expressions were considerably up-regulated in the model group at all time-points (P<0.05).Compared with the model group, the cell apoptotic indexes in gastrocnemius were significantly lower in the three EA subgroups (P<0.05).Bcl-2 protein expressions were markedly up-regulated while Bax, Cyt-C and Caspase-3 protein expressions were significantly down-regulated in the EA group 14, 21 days after modeling compared with the corresponding model subgroups (P<0.05).The changes of Caspase-3 mRNA expression levels of gastrocnemius in all groups were similar to those of Caspase-3 protein expressions.Conclusion Electroacupuncture intervention can effectively increase Bcl-2 expression and decrease Bax, Cyt-C and Caspase-3 expression in gastrocnemius muscle, and consequently reduce the apoptosis of muscle cell, which may contribute to its effect in delaying the skeletal muscle atrophy of denervated sciatic nerve.