温针灸干预慢性疲劳综合征大鼠骨骼肌PINK1/Parkin通路的变化

Effect of warm acupuncture on PINK1/Parkin pathway in the skeletal muscle of rats with chronic fatigue syndrome

背景:研究发现慢性疲劳综合征患者线粒体的功能异常,给予辅酶后可改善症状,温针灸是治疗该病的重要方法之一,但其作用机制尚不明确。目的:采用温针灸干预慢性疲劳综合征大鼠骨骼肌PINK1/Parkin通路,明确温针灸对慢性疲劳综合征的治疗机制。方法:将32只雄性SD大鼠适应性喂养3 d后随机分为正常组、模型组、温针灸组和辅酶组,每组各8只,除正常组外,其余各组大鼠以游泳力竭、慢性束缚及禁食多因素方法制备慢性疲劳综合征模型。造模成功后正常组、模型组大鼠采取相同固定及灌胃操作,温针灸组大鼠选用关元、中脘、足三里(双)穴进行治疗,1次/d,进针后将艾柱置于针柄点燃,每次治疗3壮,共15 min;辅酶组按照1 mg/kg进行灌胃,1次/d,共治疗14 d。记录实验期间各组大鼠体质量、力竭游泳时间及治疗期间的食物利用率。治疗结束后,取各组大鼠双侧腓肠肌,苏木精-伊红染色法观察各组大鼠腓肠肌病理形态,透射电镜观察各组大鼠腓肠肌线粒体形态结构及自噬体,免疫组化法检测各组大鼠骨骼肌中微管相关蛋白1轻链3(microtubule associated protein 1 light chain 3,LC3)Ⅱ蛋白表达水平,Western blot法检测各组骨骼肌中PINK1、Parkin、LC3蛋白的表达。结果与结论:①与正常组相比,模型组腓肠肌细胞核固缩、凝聚,数目增多,细胞排列紊乱,腓肠肌纤维排列紧密;温针灸组和辅酶组腓肠肌纤维排列间隙较模型组增加,细胞核减少,细胞排列较模型组整齐。②与正常组比较,模型组骨骼肌线粒体肿胀、融合及空泡化,线粒体膜断裂,基质较多溶解,嵴断裂、消失;存在自噬现象。与模型组比较,温针灸组及辅酶组线粒体数量增多,排列相对整齐,线粒体空泡化及线粒体嵴断裂情况改善,膜结构相对完整;存在自噬现象。③与正常组相比,模型组骨骼肌中PINK1蛋白表达上调(P<0.05)、而Parkin、LC3Ⅱ、LC3Ⅱ/Ⅰ蛋白的表达稍有上调(P>0.05);与模型组相比,温针灸组和辅酶组骨骼肌中PINK1、Parkin、LC3Ⅱ、LC3Ⅱ/Ⅰ蛋白表达明显上调(P<0.05),温针灸组蛋白表达上调更为显著。④结果说明,温针灸可能通过激活PINK1/Parkin通路,上调LC3Ⅱ表达,形成线粒体自噬体,促进降解受损线粒体的相关内容物,改善线粒体质量,从而发挥治疗慢性疲劳综合征的作用。

BACKGROUND:It has been found that mitochondrial function is abnormal in patients with chronic fatigue syndrome,and the administration of coenzymes can improve the symptoms.Warm acupuncture is one of the most important treatments for this disease,but its mechanism of action is unclear.OBJECTIVE:To investigate the effects of warm acupuncture on the phosphatase and tensin inducible kinase 1(PINK1)/Parkin pathway in the skeletal muscle of rats with chronic fatigue syndrome.METHODS:After 3 days of adaptive feeding,32 male Sprague-Dawley rats were randomly divided into normal control,model,warm acupuncture,and coenzyme Q groups with 8 rats in each group.The chronic fatigue syndrome model was established by multiple factors,including swimming exhaustion,chronic immobilization and fasting.After successful modeling,the normal group and the model group were treated with the same fixation and gavage procedures,and the warm acupuncture group was treated with acupuncture at Guanyuan,Zhongwan and Zusanli(bilateral)points,once a day.After the needling was inserted,the moxa pillar was put on the needle handle and ignited,three sessions once.The coenzyme Q group was given 1 mL/kg coenzyme by gavage,once a day for 14 days.The body mass,exhaustive swimming time and food utilization rate during the treatment were recorded.After the treatment,the bilateral gastrocnemius muscles of rats in each group were collected.The pathological morphology of the gastrocnemius muscle was observed by hematoxylin-eosin staining,the mitochondrial morphology and autophagosome of the gastrocnemius muscle were observed by transmission electron microscope.The expression level of microtubule-associated protein light chain 3(LC3)II protein in the skeletal muscle was detected by immunohistochemistry.Western blot was used to detect the expression of PINK1,Parkin,LC3 I,and LC3 II in the skeletal muscle.RESULTS AND CONCLUSION:Compared with the normal group,the gastrocnemius muscle nuclei of the model group were pyknotic,condensed,the number of cells was increased,the cells were arranged disorderly,and the fibers in the gastrocnemius muscle were tightly arranged in the model group.Compared with the model group,the intercellular space became smaller,the nuclei were reduced,and the cell arrangement was orderly in the warm acupuncture group and coenzyme Q group.Compared with the normal group,the skeletal muscle mitochondria in the model group were swollen,fused,and vacuolated seriously,the membrane was partially broken,the matrix was more dissolved,the cristae was broken and disappeared,and autophagy appeared.Compared with the model group,the number of mitochondria increased,the arrangement was relatively neat,mitochondrial vacuolization and rupture of cristae in the gastrocnemius muscle were improved,the membrane structure was relatively intact,and autophagy occurred.Compared with the normal group,the expression of PINK1 protein in the skeletal muscle of the model group was significantly increased(P<0.05),while the expression of Parkin,LC3 II and LC3 II/I protein was slightly upregulated(P>0.05).Compared with the model group,the protein expressions of PINK1,Parkin,LC3 II and LC3 II/I were significantly upregulated in the warm acupuncture and coenzyme Q groups(P<0.05),and the up-regulation was more significant in the warm acupuncture group.To conclude,warm acupuncture can play a role in the treatment of chronic fatigue syndrome by activating the PINK1/Parkin pathway,upregulating LC3 II expression,forming mitochondrial autophagosomes,promoting the degradation of damaged mitochondria,and improving mitochondrial quality.