电针对失神经骨骼肌萎缩大鼠自噬相关因子的影响

Effects of Electroacupuncture on Autophagy-related Factors in Rats with Denervated Skeletal Muscle Atrophy

目的探讨电针对失神经骨骼肌萎缩大鼠自噬相关因子的影响。方法健康SD大鼠30只随机分为假手术组、模型组、电针组,每组10只。采用暴露并切断坐骨神经的方法制备失神经骨骼肌萎缩大鼠模型,假手术组只暴露坐骨神经不离断神经。造模后第2天,电针组电针术侧足三里、承山两穴,每日1次,每次10 min;其余两组只固定,不作处理,连续干预21 d。测定术侧腓肠肌湿重比,HE染色观察腓肠肌组织病理变化,Masson染色观察腓肠肌纤维变化,Western blot检测腓肠肌组织p62、LC3Ⅱ/LC3Ⅰ、Beclin-1蛋白表达,qRT-PCR检测腓肠肌组织Beclin-1、Vps34、LC3Ⅱ/LC3ⅠmRNA表达。结果与假手术组比较,模型组腓肠肌湿重比明显下降,腓肠肌组织内部肌纤维严重萎缩变形,p62、LC3Ⅱ/LC3Ⅰ、Beclin-1蛋白和Beclin-1、Vps34、LC3Ⅱ/LC3ⅠmRNA水平明显升高(P<0.05);与模型组比较,电针组的腓肠肌湿重比明显升高,腓肠肌萎缩较模型组明显减轻,电针组可明显降低Beclin-1蛋白和Beclin-1、Vps34、LC3Ⅱ/LC3ⅠmRNA水平(P<0.05)。结论电针干预能下调失神经骨骼肌萎缩大鼠腓肠肌中Beclin-1、Vps34、LC3Ⅱ/LC3Ⅰ表达,提示电针可能通过抑制细胞自噬的激活,稳定细胞内环境,延缓肌萎缩的进程。

Objective To explore the effects of electroacupuncture(EA)on the autophagy-related factors in rats with denervated skeletal muscle atrophy.Method Thirty healthy Sprague-Dawley(SD)rats were randomized into a sham operation group,a model group and an EA group,with 10 rats in each group.The rat model of denervated skeletal muscle atrophy was developed by exposing and cutting off the sciatic nerve,while the rat’s sciatic nerve was only exposed but not cut off in the sham operation group.From the second day after modeling,the EA group received EA at Zusanli(ST36)and Chengshan(BL57)of the operation side,once a day,10 min each time,while the other two groups only received fixing without any other intervention,all for 21 consecutive days.The wet weight ratio of gastrocnemius muscle was measured,the histopathological changes of gastrocnemius muscle was observed after HE staining,and the changes in gastrocnemius muscle fibers were observed using Masson staining,the protein levels of p62,LC3Ⅱ/LC3Ⅰand Beclin-1 in gastrocnemius tissues were tested using Western blot,and the mRNA expressions of Beclin-1,Vps34 and LC3Ⅱ/LC3Ⅰin gastrocnemius tissues were detected using qRT-PCR.Result Compared with the sham operation group,the wet weight ratio of gastrocnemius muscle declined,the gastrocnemius muscle fibers showed significant atrophic changes,and the protein levels of p62,LC3Ⅱ/LC3Ⅰand Beclin-1 and the mRNA levels of Beclin-1,Vps34 and LC3Ⅱ/LC3Ⅰincreased significantly in the model group(P<0.05).Compared with the model group,the wet weight ratio of gastrocnemius muscle increased notably,the atrophic changes of gastrocnemius muscle reduced markedly,the protein level of Beclin-1 and the mRNA levels of Beclin-1,Vps34 and LC3Ⅱ/LC3Ⅰdropped in the EA group(P<0.05).Conclusion EA intervention can down-regulate the expressions of Beclin-1,Vps34 and LC3Ⅱ/LC3Ⅰin gastrocnemius muscle in rats with denervated skeletal muscle atrophy,suggesting that EA may stabilize the intracellular environment and prolong the muscle atrophy progression via inhibiting the activation of cell autophagy.