Effect Of Electroacupuncture On PI3K/Akt/mTOR Singaling Pathway In Rats With Denervated Skeletal Muscle

ObjectiveTo investigate effects of electroacupuncture on muscle satellite cell and PI3K/Akt/mTOR singaling pathway in rats with denervated skeletal muscle atrophy,and to discuss the possible mechanism of electroacupunctrue therapy on retarding of denervated skeletal muscle atrophy.Methods70 male Sprague-Dawley rats were randomized to 4 groups: Normal group,Control group,Model group,EA group.Model group and EA group were made the model of denervated skeletal muscle atrophy by way of exposed and crosscuted the rat sciatic nerve,and Control group only exposed sciatic nerve but not cut off.Electroacupuncture was given to rats in EA group on the operation side after 1 d modeling,EA(5 Hz,1.5 mA)was applied to”Zusanli”(ST 36)and”Chengshan”(BL 57)for 10 min.3 groups were divided randomly into three subgroups with 7,14,21 days of postoperation.The muscle wet weight ratio in the operational gastrocnemius were measured,the pathologic changes of the muscle were detected by HE staining,fiber diameter and cross-sectional area of the operational gastrocnemius were determined by masson staining.Caspases-3,PCNA,Myostatin,IGF-1,PI3 K,Akt and mTOR protein expression and gene expression were detected by Western blot and RT-PCR.The phosphorylation level of Akt and mTOR were observed by Western blot.ResultsThe wet weight ratio,and fiber diameter and cross-sectional area were significantly lower in the two groups of Model group and EA group than those in Control group(P<0.001),and the wet weight ratio,fiber diameter and cross-sectional area were observably heigher in EA group than those in Model group(P<0.05).While compared to Model group and Control group,the protein expression of PCNA,IGF-1,PI3 K,p-Akt and p-mTOR in EA group were heigher markedly(P<0.05).the protein expression of Myostatin were mroe lower in EA group than those in Model group(P<0.05).Compared to the control group,gastrocnemius Caspase-3 protein considerably up-regulated in the two groups of model group and EA group(P<0.05).Following 14 d of EA intervention,Caspase-3 protein remarlably down-regulate in the EA group(P<0.05).the gene expression of PCNA,IGF-1,PI3 K,Akt and mTOR were mroe heigher in EA group than those in model groups(P<0.05).the gene expression of Myostatin were mroe lower in EA group than those in model group(P<0.05).Compared to the control group,the gene expression of Caspase-3 considerably up-regulated in the two groups of model group and EA group(P<0.05).Following 14 d of EA intervention,the gene expression of Caspase-3 remarlably down-regulate in the EA group(P<0.05).Conclusionelectroacupuncture can retrad the process of denervated skeletal muscle atrophy.then electroacupuncture can increase expression of PI3K/Akt/mTOR signaling pathways to promote the proliferation of muscle satellite cells and inhibit the apoptosis of muscle cells,which could be one of mechanism to retrad the peed of denervated skeletal muscle atrophy.