针刺夹脊穴对衰老模型大鼠骨骼肌AMPK/SIRT1/PGC-1α信号通路的影响

关键词：衰老性骨骼肌萎缩  针刺  夹脊穴  单磷酸腺苷活化蛋白激酶/沉默信息调节因子1/过氧化物酶增殖物激活受体γ共激活因子1α信号通路

Keywords:age-related sarcopenia  acupuncture  Jiaji acupoint  AMPK/SIRT1/PGC-1α signaling pathway

摘要：

      摘要 目的：观察针刺夹脊穴对衰老大鼠骨骼肌AMPK/SIRT1/PGC-1α信号通路的影响，探讨针刺延缓腰部骨骼肌衰老性骨骼肌萎缩的可能机制。 方法：40只SD雄性大鼠随机分为空白组、模型组、针刺组、非穴组。空白组大鼠每日项背部皮下注射生理盐水，其余3组大鼠每日项背部皮下注射D-gal，每日1次，连续12周，自第9周起进行针刺干预。针刺组取双侧L3—L5夹脊穴，非穴组取大鼠双侧非经非穴，每日1次，持续4周。测量各组大鼠体重及终末体质量增长率，采用抓力测试检测大鼠肌力，HE染色观察大鼠腰部骨骼肌萎缩情况，生化检测大鼠血清超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-PX）含量，实时荧光定量PCR检测单磷酸腺苷活化蛋白激酶α（AMPKα）、沉默信息调节因子1（SIRT1）、过氧化物酶增殖物激活受体γ共激活因子1α（PGC-1α）、细胞周期蛋白依赖性激酶抑制因子1A（P21）、肿瘤抑制蛋白53（ P53） mRNA的相对表达量。 结果：同空白组相比，模型组、针刺组、非穴组大鼠体质量减轻（P＜0.01，P＜0.05，P＜0.01），终末体重增长率差异有显著性（P＜0.001，P＜0.001，P＜0.001）。干预前，与空白组相比，模型组、针刺组、非穴组大鼠抓力均下降（P＜0.01，P＜0.01，P＜0.01），而3组大鼠之间的抓力无差异（P＞0.05）。干预后，模型组大鼠抓力明显低于空白组（P＜0.001），腰部骨骼肌细胞出现萎缩，具体表现在骨骼肌肌纤维面积和纤维直径下降（P＜0.001，P＜0.01），大鼠血清中SOD、GSH-PX的活力下降（P＜0.001，P＜0.001），MDA含量显著升高（P＜0.01），腰部骨骼肌组织中AMPKα、SIRT1、PGC-1α mRNA表达显著降低（P＜0.001，P＜0.001，P＜0.01），P21、P53 mRNA相对表达量比空白组高（P＜0.05，P＜0.01）。与模型组相比，针刺组大鼠抓力升高（P＜0.001），大鼠腰部骨骼肌萎缩程度较模型组大鼠有所改善，骨骼肌肌纤维面积和直径增加（P＜0.01，P＜0.05），针刺夹脊穴上调了大鼠血清中SOD活力、GSH-PX活力（P＜0.001，P＜0.01），抑制了血清中MDA的表达（P＜0.05），AMPKα、SIRT1、PGC-1α mRNA的表达量升高（P＜0.001，P＜0.01，P＜0.05），P21、P53 mRNA相对表达量下降（P＜0.05，P＜0.01），而非穴组大鼠未见显著差异（P＞0.05）。 结论：针刺夹脊穴可使衰老模型大鼠腰部骨骼肌萎缩情况有所缓解，提高了衰老大鼠肌力，抑制氧化应激反应，这可能是通过AMPK/SIRT1/PGC-1α通路发挥作用。

Abstract:

      Abstract Objective： To observe the effect of acupuncture on the AMPK/SIRT1/PGC-1α signaling pathway in skeletal muscle of aging rats， and to explore the possible mechanism of acupuncture in delaying aging skeletal muscle atrophy in lumbar skeletal muscle. Method： Forty male SD rats were randomly divided into blank group， model group， acupuncture group and non-acupoint group. The blank group received daily subcutaneous injections of normal saline in the dorsal neck region. The other three groups received daily subcutaneous injections of D-galactose (D-gal) in the same region for 12 weeks to induce aging. Starting from week 9, acupuncture intervention was performed for 4 weeks. The acupuncture group took bilateral L3—L5 Jiaji points， and the non-acupoint group took bilateral non-meridian and non-acupoint points. Body weight and growth rates were measured, and muscle strength was evaluated using a grip strength test. Lumbar skeletal muscle atrophy was assessed using hematoxylin and eosin staining. Serum levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-PX) were analyzed biochemically. Relative expression levels of AMPKα， SIRT1， PGC-1α， P21 and P53 mRNA were detected by real-time quantitative PCR. Result： Compared with the blank group， the body weight of the model group， the acupuncture group and the non-acupoint group was reduced （P<0.01， P<0.05， P<0.01）， and the difference in terminal body weight growth rate was significant （P<0.001 for all）. Before intervention， grip strength was significantly reduced in all experimental groups compared to the blank group (P<0.01 for all), with no significant differences among the experimental groups (P>0.05) . After the intervention， the model group showed significantly lower grip strength compared to the blank group (P<0.001), accompanied by evident lumbar skeletal muscle atrophy, as reflected by reduced muscle fiber area and diameter (P<0.001, P<0.01). Additionally， serum SOD and GSH-PX activities decreased（P<0.001， P<0.001）， while MDA increased significantly （P<0.01）. The mRNA expression levels of AMPKα， SIRT1， and PGC-1α decreased significantly （P<0.001， P<0.001， P<0.01）， while the relative mRNA expression levels of P21 and P53 were higher than those in the blank group （P<0.05， P<0.01）. Compared with the model group， the acupuncture group demonstrated increased grip strength (P<0.001), improved skeletal muscle fiber area and diameter (P<0.01, P<0.05), enhanced serum SOD and GSH-PX activities (P<0.001, P<0.01), reduced serum MDA levels (P<0.05), and elevated AMPKα, SIRT1, and PGC-1α mRNA expression (P<0.001, P<0.01, P<0.05). Moreover, P21 and P53 mRNA expression levels were significantly reduced in the acupuncture group (P<0.05, P<0.01)， while there was no significant difference in the non-acupoint group （P>0.05）. Conclusion： Acupuncture at Jiaji points alleviated the atrophy of lumbar skeletal muscles， improved muscle strength and inhibited oxidative stress in aging rats. These effects may be mediated through the AMPK/SIRT1/PGC-1α signaling pathway.