细胞自噬功能状态在心肌和骨骼肌运动适应中的作用

发布时间：2018-02-26 19:30

本文关键词： 细胞自噬运动能力 Beclin1 Bcl-2 Glut4 NRF-2　出处：《武汉体育学院》2017年硕士论文　论文类型：学位论文

【摘要】：目的细胞自噬的功能状态对于运动诱导的肌细胞自噬激活以调节肌肉代谢、内环境稳态水平而实现运动适应与运动能力提高有着重要意义。本文旨在通过不同运动方式及运动时间的小鼠运动实验模型,探讨运动对于骨骼肌和心肌细胞自噬激活的相关分子机制,为提高机体运动能力与预防肌肉相关的病变或其它慢性疾病提供理论依据。方法取8周龄昆明小鼠90只,随机分为短期运动组和长期运动组,其中短期运动组50只,长期运动组40只。长期运动组又随机分为4组:对照组、自由转轮组、跑台组和游泳组,每组各10只。短期运动组适应性训练结束后,分别进行无负重游泳运动0、0.5、1、1.5与2 h。长期运动组中,跑台组以15 m/min进行运动训练1 h,每天1次,训练时间为2个月。游泳组每天无负重游泳1 h,运动训练时间为2个月。自由转轮组让小鼠生活在自由转轮笼中自主运动,训练时间同样为2个月。运动结束后,取小鼠骨骼肌、心肌等组织备用。以Western blot方法检测心肌、骨骼肌中自噬相关蛋白Beclin1、LC-3、AMPK-?、PGC-1?、抗凋亡蛋白Bcl-2、抗氧化因子NRF-2及糖转运蛋白Glut4的表达,并用透射电镜观察肌肉中自噬激活的状况或线粒体质量的状况。结果1.短期运动后,细胞自噬相关蛋白如PGC-1?、AMPK-?和Beclin1在骨骼肌组织中均显著上调(P0.05);糖转运蛋白Glut4在小鼠运动1.5 h与2 h后表达量急剧上升。2.短期运动后,小鼠在运动1 h和1.5 h时,自噬相关基因Beclin1在心肌中的表达量达到最高水平(P0.05),NRF-2在运动0.5 h和1 h时呈现较高的表达量(P0.05)。3.长期运动后,细胞自噬相关蛋白如Beclin1和LC-3在骨骼肌组织均显著上调(P0.05);自由转轮运动训练对于Glut4表达则呈现出更为明显的上调(P0.05)。4.经过不同运动方式训练后,均能提高细胞自噬相关蛋白Beclin1、抗氧化转录因子NRF-2在心肌中的表达(P0.05),尤其是跑台和游泳运动能更大程度地促进Beclin1的表达上调(P0.05)。5.与短期运动不同的是,长期运动可以降低Bcl-2的表达而抑制细胞凋亡(P0.05)。6.在进行长期运动训练过程中,游泳运动比跑台运动和自由转轮运动能更大程度地增加Bcl-2的表达(P0.05)。结论适度的运动可以激活骨骼肌、心肌细胞的自噬,长期中等强度运动训练可以促进细胞自噬的激活,进一步提高机体内环境的稳定与能量代谢的平衡和利用率,对于肌肉运动适应与运动能力的提高起着重要的作用;同时,运动诱导的细胞自噬激活与葡萄糖转运蛋白Glut4表达的上调,加强了机体对葡萄糖的转运与利用,促进了肌肉质量的维持,有利于慢性疾病如糖尿病或衰老性肌萎缩的预防与治疗。
[Abstract]:Objective the functional state of autophagy regulates muscle metabolism by activation of muscle cell autophagy induced by exercise. It is of great significance to achieve motor adaptation and exercise ability improvement at the level of homeostasis in the internal environment. The purpose of this paper is to establish an experimental model of exercise in mice with different exercise patterns and time. To explore the molecular mechanism of exercise on autophagy of skeletal muscle and cardiomyocytes, and to provide theoretical basis for improving the ability of exercise and preventing musculosis-related lesions or other chronic diseases. Methods 90 Kunming mice aged 8 weeks were selected. They were randomly divided into short-term exercise group (n = 50) and long-term exercise group (n = 40). The long-term exercise group was randomly divided into four groups: control group, free wheel group, treadmill group and swimming group. There were 10 rats in each group. After the adaptive training, the short term exercise group was treated with 0. 5 and 1. 5 and 2 hours of weightless swimming respectively. In the long term exercise group, the platform group was trained for 1 hour at 15 m / min, once a day. The training time was 2 months. The swimming group had 1 hour of swimming without load and 2 months of exercise training. The free wheel group allowed the mice to live in the free wheel cage and exercise independently, and the training time was also 2 months. Western blot method was used to detect the autophagy associated protein Beclin1 LC-3 AMPK-3? PGC-1? The expression of anti-apoptotic protein Bcl-2, antioxidant factor NRF-2 and glucose transporter Glut4, and the status of autophagy activation or mitochondrial mass in muscle were observed by transmission electron microscope. Results 1.After short-term exercise, autophagy related proteins such as PGC-1? AMPK-? The expression of glucose transport protein (Glut4) in skeletal muscle was significantly up-regulated after 1. 5 h and 2 h of exercise, and the expression of glucose transporter Glut4 was significantly increased at 1 h and 1. 5 h after exercise for 1 h and 1. 5 h after exercise for 1 h and 1. 5 h, respectively. The expression of autophagy related gene Beclin1 in myocardium reached the highest level. NRF-2 showed a higher expression at 0.5 h and 1 h of exercise. Autophagy associated proteins such as Beclin1 and LC-3 were significantly up-regulated in skeletal muscle tissues, while free wheel exercise showed a more significant up-regulation of Glut4 expression. The expression of antioxidant transcription factor (NRF-2) in myocardium was increased, especially in treadmill and swimming exercise, which could promote the expression of Beclin1 to a greater extent. Different from short-term exercise, it was different from short-term exercise. Long-term exercise can reduce the expression of Bcl-2 and inhibit apoptosis. During long-term exercise training, swimming can increase the expression of Bcl-2 to a greater extent than treadmill exercise and free wheel exercise. Conclusion moderate exercise can activate skeletal muscle. Myocardial autophagy and long-term moderate exercise training can promote the activation of autophagy and further improve the stability of the environment and the balance and utilization of energy metabolism. At the same time, autophagy induced by exercise and up-regulated expression of glucose transporter Glut4 enhance the transport and utilization of glucose. Promote the maintenance of muscle quality, is conducive to the prevention and treatment of chronic diseases such as diabetes or aging muscle atrophy.
【学位授予单位】：武汉体育学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R87

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