电针对糖尿病小鼠骨骼肌磷酸化蛋白激酶B、天冬氨酸特异性半胱氨酸蛋白酶-3蛋白表达的影响

Effect of Electroacupuncture on Expression of Caspase-3 and Phosphorylated Akt Proteins in the Skeleton Muscle in Diabetic Mice

目的:探讨电针对糖尿病小鼠骨骼肌天冬氨酸特异性半胱氨酸蛋白酶(caspase-3)、磷酸化蛋白激酶B(pAkt)的影响,为针灸在临床上治疗糖尿病骨骼肌病变提供实验依据。方法:将18只C 57小鼠随机分为对照组、模型组和电针组,每组6只。注射链脲佐菌素建立糖尿病模型。电针组电针"足三里""阳陵泉"穴,连续波,频率20～30Hz,强度1mA,每次20min,每日1次,连续14d。取比目鱼肌、跖肌、腓肠肌、趾长伸肌和胫骨前肌分别进行肌肉湿重比较,采用Western blot方法检测pAkt(ser 473)、pAkt(Thr 308)、总Akt、caspase-3的蛋白表达。结果:与对照组相比,造模后5条肌肉湿重明显减轻(P<0.01),而电针组与模型组相比可增加肌肉湿重(P<0.05,P<0.01)。总Akt 3组间比较差异无统计学意义(P>0.05)。pAkt(Thr 308)的表达模型组较对照组明显下调(P<0.01),pAkt(ser 473)模型组与对照组相比差异不明显(P>0.05),而电针治疗较模型组表达上调(P<0.01)。与对照组相比,模型组caspase-3明显增高(P<0.01),而电针组与模型组相比能明显下调caspase-3的表达(P<0.01)。结论:电针能够对糖尿病小鼠骨骼肌病变发挥治疗作用,其机制部分是通过促进pAkt(ser 473)/pAkt(Thr 308)、抑制caspase-3的表达实现的。

Objective To observe the effect of electroacupuncture（EA） on expression of phosphorylated（pAkt） and caspase-3 proteins in the skeletal muscle in mice with diabetes,so as to provide experimental evidence for treating diabetic myopathy in clinic.Methods Eighteen C 57 mice were equally randomized into control,model and EA groups（n=6 mice/group）.Type 1 diabetic model was established by streptozotocin（STZ,i.P.,200 mg/kg）.EA（1 mA,20-30 Hz） was applied to bilateral ＂Zusanli＂（ST 36） and ＂Yanglingquan＂（GB 34） for 20 min,once daily for 14 days.Damp weights of the musculus soleus,plantaris,gastrocnemius,extensor digitorum longus and tibialis anterior were measured,and Western blot was used to measure the expression levels of pAkt（ser 473）,pAkt（Thr 308）,total Akt and caspase-3 proteins in the aforementioned skeleton muscles.Results Compared with the normal control group,the weights of the musculus soleus,plantaris,gastrocnemius,extensor digitorum longus and tibialis anterior were decreased obviously in the model group（P0.01）.After EA treatment,the weights of the 5 skeleton muscles were all increased apparently compared with the model group（P0.05）.In comparison with the normal control group,muscular pAkt（Thr 308） protein expression level was down-regulated significantly in the model group（P0.01）,while that of muscular caspase-3 protein expression of the model group was up-regulated considerably（P0.01）.Following EA,the expression levels of muscular pAkt（Thr 308） and pAkt（ser 473） in the EA group were upregulated apparently（P0.01）,while that of muscular caspase-3 protein was down-regulated obviously（P0.01）.No significant differences were found between the control and model groups in the expression levels of muscular pAkt（ser 473） and total Akt proteins（P0.05）.Conclusion EA intervention can effectively up-regulate expression of pAkt（Thr 308 and ser 473） and down-regulate expression of caspase-3 protein in the skeleton muscle in diabetic mice,which may contribute to its effect in inhibiting diabetic myopathy.