摘要
背景:衰老所引发的肌萎缩(肌少症)和肌无力正日益成为严重的健康问题,目前尚缺乏有效的药物治疗方法。运动训练尤其是抗阻运动对预防肌萎缩具有重要作用,然而分子机制目前尚未完全明晰。目的:探讨规律抗阻运动对衰老大鼠骨骼肌卫星细胞的影响及可能的作用机制。方法:45只20月龄雄性SD大鼠随机分为衰老安静组、衰老运动组和衰老运动抑制剂组,另取10只6月龄雄性SD大鼠作为青年安静组。青年安静组和衰老安静组在鼠笼内安静饲养,衰老运动组进行负重爬梯训练,衰老运动抑制剂组在训练同时腹腔注射脂联素受体1抑制剂,干预周期为12周。干预后,采用递增负荷跑台运动实验、渐进式尾部负重爬梯运动实验测定大鼠耐力水平以及力量水平;分离腓肠肌,采用酶联免疫吸附法测定脂联素水平,苏木精-伊红染色获取细胞横截面积,实时荧光定量PCR测定线粒体DNA拷贝数,增殖细胞核抗原免疫组织化学染色法检测肌细胞增殖情况,配对盒基因7/成肌分化因子免疫荧光染色法检测活化的卫星细胞数量,免疫印迹法检测骨骼肌中相关蛋白表达量。使用脂联素受体1激动剂AdiopRon与体外培养的卫星细胞共孵育24 h,配对盒基因7/成肌分化因子免疫荧光染色法检测活化的卫星细胞数量,免疫印迹法检测腺苷酸活化蛋白激酶蛋白表达量。结果与结论:①与衰老安静组比较,衰老运动组的耐力和力量水平、腓肠肌质量指数、脂联素水平、细胞横截面积、线粒体DNA拷贝数、增殖细胞核抗原阳性细胞数、配对盒基因7/成肌分化因子阳性细胞数升高(P<0.05),总蛋白含量以及脂联素受体1、过氧化物酶体增殖物激活受体γ辅激活子1α、核呼吸因子1、线粒体转录因子A、蛋白激酶B、哺乳动物雷帕霉素靶蛋白、P70核糖体蛋白S6激酶、配对盒基因7、成肌分化因子、肌细胞生成素、生肌因子5蛋白表达量上调(P<0.05);②运动对衰老骨骼肌的上述益处在给予脂联素受体1抑制剂处理后被削弱(P<0.05);③细胞培养实验发现,AdiopRon能够增加配对盒基因7/成肌分化因子阳性细胞数量以及卫星细胞腺苷酸活化蛋白激酶蛋白表达量。结果表明:规律抗阻运动通过脂联素受体1途径激活衰老大鼠卫星细胞,进而促进肌细胞增殖并恢复骨骼肌质量和功能。脂联素受体1是规律运动延缓衰老所致肌肉质量流失和力量下降的关键作用靶点。
BACKGROUND:Muscle atrophy(sarcopenia)and muscle weakness caused by aging are becoming increasingly serious health problems,and there is currently a lack of effective drug treatments.Exercise training,especially resistance exercise,plays an important role in preventing muscle atrophy;however,its molecular mechanism is not yet fully understood.OBJECTIVE:To explore the effects of regular resistance exercise on skeletal muscle satellite cells in aging rats and the possible mechanism.METHODS:Forty-five 20-month-old male SD rats were randomly divided into old sedentary,old exercise,or old exercise inhibitor groups,and ten 6-month-old male SD rats were selected as young sedentary group.Rats in young sedentary and old sedentary groups were kept quietly in mouse cage,while those of old exercise group performed weight-bearing ladder training and old exercise inhibitor group was given administration with adiponectin receptor 1 inhibitor while exercising,in which the intervention period was lasting for 12 weeks.After the intervention,the endurance and strength levels were determined by grated treadmill exercise test and progressive tail-loaded ladder exercise test,respectively.The gastrocnemius was isolated,and the adiponectin content was detected by enzyme-linked immunosorbent assay.The cell cross-sectional area was measured by hematoxylin-eosin staining.The mitochondrial DNA copy number was examined by real-time fluorescence quantitative PCR.Cell proliferation was detected by proliferating cell nuclear antigen immunohistochemical staining.The number of activated skeletal muscle satellite cells was measured by paired box gene 7/myogenic differentiation antigen immunofluorescence staining.Immunoblotting was used to detect the expression of related proteins in skeletal muscle.Adiponectin receptor 1 agonist AdiopRon was co-incubated with satellite cells cultured in vitro for 24 hours.Paired box gene 7/myogenic differentiation antigen immunofluorescence staining was used to detect the number of activated satellite cells.Western blotting was used to detect the expression of AMP-activated protein kinase protein in satellite cells.RESULTS AND CONCLUSION:(1)Compared with old sedentary group,endurance and strength level,gastrocnemius mass index,adiponectin content,cell cross-sectional area,mitochondrial DNA copy number,cell proliferation by proliferating cell nuclear antigen+cell counts,and paired box gene 7+/myogenic differentiation antigen+cell counts were increased(P<0.05);total protein content and protein expression of adiponectin receptor 1,peroxisome proliferatoractivated receptorγcoactivator 1-alpha,nuclear respiratory factor 1,mitochondrial transcription factor A,protein kinase B,mammalian target of rapamycin,P70 Ribosomal protein S6 kinase,paired box gene 7,myogenic differentiation antigen,myogenin,and myogenic factor 5 were upregulated(P<0.05)in the old exercise group.(2)The above benefits of exercise on aging skeletal muscle were diminished after administration with adiponectin receptor 1 inhibitor(P<0.05).(3)Cell culture experiments found that AdiopRon could increase the number of paired box gene 7+/myogenic differentiation antigen+cells and the expression of AMP-activated protein kinase protein in satellite cells.These findings indicate that regular resistance exercise activates satellite cells through adiponectin receptor 1 pathway,thereby promoting muscle cell proliferation and restoring skeletal muscle quality and function in aged rats.Adiponectin receptor 1 is a key target for regular exercise to protect against muscle mass loss and strength decline during aging.
作者
潘冬
杨加玲
田卫
王东济
朱政
马文超
刘娜
付常喜
Pan Dong;Yang Jialing;Tian Wei;Wang Dongji;Zhu Zheng;Ma Wenchao;Liu Na;Fu Changxi(School of Physical Education,Lianyungang Normal College,Lianyungang 222006,Jiangsu Province,China;Department of Endocrinology,Lianyungang Hospital of Traditional Chinese Medicine,Lianyungang 222100,Jiangsu Province,China;Department of Physical Education,Xuzhou University of Technology,Xuzhou 221008,Jiangsu Province,China)
出处
《中国组织工程研究》
北大核心
2026年第7期1736-1746,共11页
Chinese Journal of Tissue Engineering Research
基金
江苏省产学研合作项目(BY20221256),项目负责人:付常喜
江苏省社会科学基金项目(22TYD001),项目负责人:付常喜。
关键词
抗阻运动
脂联素
脂联素受体1
骨骼肌
衰老
卫星细胞
resistance exercise
adiponectin
adiponectin receptor 1
skeletal muscle
aging
satellite cell
