电针“委中”穴调节PGC-1α及相关影响因子对腰多裂肌损伤大鼠线粒体功能的影响

Effect of electroacupuncture at “Weizhong”(BL40)on expression of PGC-1α and related factors on mitochondrial function in rats with lumbar multifidus muscle injury

目的 通过观察电针“委中”穴对腰多裂肌损伤大鼠过氧化物酶体增殖物活化受体γ共刺激因子-1α(peroxisome proliferator-activated receptor γ coactivator-1α,PGC-1α)及相关因子表达对线粒体功能变化的影响,阐释电针修复骨骼肌损伤的部分机制。方法 72只SD大鼠按随机数字表分为正常组、模型组和电针组,各组再按时间点分为4个亚组,每组6只。正常组不做任何处理,其余2组采用注射布比卡因制备腰多裂肌损伤模型。电针组电针“委中”穴,每次治疗30分钟,每日1次,4个亚组分别干预1天、2天、3天和7天。取材后,多裂肌分别进行苏木精—伊红染色(hematoxylin-eosin staining, HE)、蛋白免疫印迹(Western blot, WB)、聚合酶链式反应(polymerase chain reaction, PCR)及生化法检测。结果 (1)HE染色观察发现,较正常组而言,肌纤维出现大面积变形,肌间隙增大、炎性细胞浸润增多。与同时间点模型组相比,电针能改善损伤情况。(2)PCR和生化法检测PGC-1α及相关因子Ca2+、钙/钙调蛋白依赖性蛋白激酶(Ca2+/calmodulin dependent protein kinaseⅡ,CaMKⅡ)和cAMP反应元件结合蛋白(cAMP-response element binding protein, CREB)表达情况,结果提示模型组和电针2天、3天亚组PGC-1α mRNA、Ca^(2+)、CaMKⅡmRNA、CREB mRNA高于正常组(P<0.01或P<0.05)。而电针2天、3天亚组PGC-1α mRNA、Ca^(2+)、CaMKⅡmRNA、CREB mRNA低于同一时间点模型组(P<0.01或P<0.05)。(3)Western blot和生化法检测线粒体功能指标线粒体外膜转位酶20(translocase of outer mitochondrial membrane 20, TOMM 20)、超氧化物歧化酶(superoxide dismutase, SOD)、三磷酸腺苷(adenosine triphosphate enzyme, ATP)酶,发现模型组和电针组低于正常组(P<0.01或P<0.05)。与同一时间点比较,发现电针组TOMM20、SOD、ATP酶高于模型组(P<0.01或P<0.05)。结论 电针可能是通过降低PGC-1α相关因子对PGC-1α的过度激活,从而保护线粒体功能,促进骨骼肌的损伤修复。

Objective To observe the effect of electroacupuncture(EA) at “Weizhong”(BL40) on the expression of peroxisome proliferator-activated receptor γ coactivator-1α(PGC-1α) and the effects of the expression of related factors to the changes of mitochondrial function in rats with lumbar multifidus muscle injury(LMMI), try to explain the mechanism of EA in repairing skeletal muscle injury.Methods 72 male SD rats were randomly divided into normal group(n=24), model group(n=24) and EA group(n=24), and these groups were further divided into four subgroups(1, 2, 3 and 7 days), with 6 rats in each group. Except the normal group, the LMMI model was established by injection of 0.5% bupivacaine. EA was applied to bilateral BL40 for 30min, once daily for 1, 2,3 and 7 days respectively. Multifidus muscle were detected by HE staining, western blot, PCR and biochemical methods. Results(1)Compared with the normal group, HE staining showed large area of damage, enlarged muscle space and inflammatory cell infiltration in the model group, which was relatively milder in the EA subgroups.(2)PCR and biochemical assays for PGC-1 α And associated factors Ca^(2+), calcium/calmodulin dependent protein kinase II(CaMK II) and cAMP response element binding protein(CREB).Compared with the normal group, the expression levels of PGC-1α mRNA,Ca^(2+),CaMKⅡ mRNA, CREB mRNA in the model and EA subgroups 2 d and 3 d were significantly increased(P<0.01, P<0.05). Compared with the model group, the expression levels of PGC-1α mRNA,Ca2+, CaMKⅡ mRNA, CREB mRNA in the EA subgroups 2d and 3d were significantly decreased(P<0.01,P<0.05).(3)The mitochondrial function indexes mitochondrial membrane 20(TOMM20), superoxide dismutase(SOD) and adenosinetriphosphate enzyme(ATPase) were lower in the model group and electroacupuncture group than in the normal group(P<0.01,P<0.05). Compared with the same time points, it was found that TOMM20, SOD, ATPase were higher in the EA group than in the model group(P<0.01,P<0.05). Conclusion Electroacupuncture may act by decreasing PGC-1 α Expression of related factors, thereby alleviating PGC-1α over activation, accelerate the process of recovery of mitochondrial function, and promote more rapid repair of skeletal muscle.