肌组织特异性microRNA介导的骨骼肌衰减机制及运动的干预研究

发布时间：2018-05-09 05:34

本文选题：microRNA + PGC-α　；参考：《西安体育学院学报》2017年06期

【摘要】：目的探讨不同运动方式对肌肉特异性microRNA在骨骼肌中表达的影响及其与骨骼肌衰减的关系。方法 3月龄雄性C57BL/6小鼠36只,随机分为年轻组、老年组、抗阻训练老年组(尾部负重爬梯训练)、有氧训练老年组,每组9只。17个月饲养训练结束后,检测小鼠股四头肌湿质量(mg)与体质量(g)的比值(SI),用实时荧光定量RT-PCR法对miRNA-1、miRNA-133a/b、miRNA-206进行检测,同时检测IGF-1、PGC-1α、MAFbx及Myostatin等mRNA及蛋白的表达。结果发现老年鼠SI值显著下降,呈现肌肉流失征象,miR-1和miR-133a下调,IGF-1mRNA表达下调,而MAFbxmRNA表达上调,提示老年小鼠骨骼肌质量下降可能与IGF-1、MAFbx对骨骼肌蛋白质合成或降解的调控有关,推测miR-1和miR-133a参与了这一调控过程。而运动可显著增加老年鼠的SI值,延缓肌肉衰减,表现为运动训练的老年鼠其骨骼肌miR-1和miR-133a表达均有显著提高,IGF-1、PGC-1αmRNA表达上调,MAFbx及Myostatin mRNA表达也上调,但年龄因素或运动训练因素对所观测基因的蛋白表达影响均不如mRNA明显,且转录和翻译水平的调控亦未呈现一致性,反映出miRNA对基因调节作用的复杂性。结论长期有氧运动或抗阻运动可有效延缓肌肉流失,肌肉特异性microRNA可能通过对涉及肌再生或肌萎缩的关键基因IGF-1、PGC-1α、MAFbx转录后或翻译水平的调节而发挥重要作用。
[Abstract]:Objective to investigate the effect of different exercise modes on the expression of muscle-specific microRNA in skeletal muscle and its relationship with skeletal muscle attenuation. Methods Thirty-six 3-month-old male C57BL/6 mice were randomly divided into three groups: young group, elderly group, resistance training group (9 rats in each group) after 17 months of feeding training (tail load climbing training group, aerobic training group, 9 mice in each group). The ratio of wet weight of quadriceps femoris to body weight of mice was detected. The expression of mRNA and protein, such as mRNA and Myostatin, were detected by real-time fluorescence quantitative RT-PCR method. The expression of mRNA and protein such as IGF-1, PGC-1 伪, MAFbx and Myostatin were detected by real-time fluorescence quantitative RT-PCR method. The results showed that the SI value of aged mice was significantly decreased, which showed that the expression of IGF-1mRNA was down-regulated by miR-1 and miR-133a, but the expression of MAFbxmRNA was up-regulated, which suggested that the decline of skeletal muscle mass in aged mice might be related to the regulation of protein synthesis or degradation in skeletal muscle by IGF-1MAFbx. It is speculated that miR-1 and miR-133a are involved in this regulation process. Exercise could significantly increase the SI value of the aged rats and delay the muscle decay. The expression of miR-1 and miR-133a in the skeletal muscle of the aged rats with exercise training was significantly increased, and the expression of IGF-1PGC-1 伪 mRNA was up-regulated, and the expression of MAFbx and Myostatin mRNA were also up-regulated. However, the effects of age or exercise training on the protein expression of the observed gene were not as obvious as those of mRNA, and the regulation of transcription and translation level was not consistent, which reflected the complexity of the regulatory effect of miRNA on gene expression. Conclusion Long-term aerobic exercise or resistance exercise can effectively delay muscle loss, and muscle-specific microRNA may play an important role by regulating the posttranscriptional or translation level of the key gene IGF-1PGC-1 伪 involved in muscle regeneration or muscle atrophy.
【作者单位】：华东师范大学体育与健康学院;华东师范大学青少年健康评价与运动干预教育部重点实验室;上海交通大学附属中学嘉定分校;上海交通大学Bio-x研究院;
【基金】：“青少年健康评价与运动干预”教育部重点实验室建设项目(40500-541235-14203/004)
【分类号】：G804.2

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