运动干预通过调控蛋白质降解通路改善衰老性肌萎缩的分子机制

发布时间：2018-06-16 17:39

本文选题：运动干预 + 衰老性肌萎缩　；参考：《武汉体育学院》2017年硕士论文

【摘要】：目的:通过自然饲养SD大鼠至21月龄构建衰老性肌萎缩模型,采用两种中等强度的运动干预方式(自由转轮和爬梯运动)探讨运动干预调控蛋白质降解通路对衰老性肌萎缩的改善作用,为衰老性肌萎缩的运动康复提供一定的理论依据,为大众健身提供一定的运动干预指导。方法:SD雄性大鼠19只饲养至21月龄用于构建衰老性肌萎缩模型,将19只老年大鼠分为老年对照组(Senior Control Group,SC)6只,老年自由转轮组(Senior Voluntary Wheel Running Group,SW)6只,老年爬梯组(Senior Ladder-Climbing Group,SL)7只;同时,用10只3月龄成年大鼠作为年轻对照组(Youth Control Group,YC)。所有四组大鼠进行运动干预8周后24小时内称取大鼠体重、眼球取血、收集腓肠肌并称重。计算各组大鼠腓肠肌湿重与体重比值以评估肌萎缩程度,检测血清超氧化物歧化酶(Superoxisome dismutase,SOD)、丙二醛(Malonaldehyde,MDA)的含量以比较各组大鼠抗氧化能力;TUNEL染色检测腓肠肌细胞凋亡率;蛋白免疫印迹检测骨骼肌能量代谢、蛋白降解和蛋白合成相关蛋白的表达。结果:1)与YC组相比,SC组大鼠腓肠肌湿重比显著下降(p0.001);运动干预后SW组和SL组大鼠湿重比显著性高于SC组(p0.05)。2)与YC组相比,SC组大鼠血清SOD显著性下降(p0.001),MDA含量显著性上升(p0.01);运动干预后SW组大鼠血清SOD显著性的上升(p0.05),SL组虽然没有显著性差异但具有上升趋势。3)HE染色结果显示,与YC组相比,SC组大鼠腓肠肌肌纤维出现明显的肌纤维萎缩和细胞核内移的现象,运动干预后这种现象明显得到改善;同时运动干预后SW和SL组大鼠腓肠肌纤维之间间隙减少,SL组肌纤维明显增粗。4)TUNEL结果显示,与YC组相比,SC组大鼠腓肠肌细胞凋亡率显著性上升(p0.001),运动干预后老年大鼠腓肠肌细胞凋亡率都有明显的下降(p0.01)。5)通过对各组大鼠腓肠肌中能量代谢相关蛋白表进行检测,SC组大鼠腓肠肌中AMPK、Sirt1、PGC-1α表达量明显下调(p0.01),运动干预后SW和SL组大鼠腓肠肌中能量代谢都有显著性上升(p0.01)6)通过对各组大鼠腓肠肌中蛋白降解通路相关蛋白表达进行检测,与YC组相比,SC组自噬水平明显降低,LC3\Atg7\Beclin1表达量明显下降(p0.01),而泛素蛋白酶标志蛋白(Fox O3a/Atrogin1)表达显著升高(p0.05),通过运动干预后自噬通路被激活,泛素蛋白酶通路相关蛋白表达下降。结论:1、衰老过程中伴随着肌肉质量的丢失,中等强度的运动干预对衰老性肌萎缩能够起到一定的康复作用。2、衰老大鼠骨骼肌出现肌纤维横截面积下降和细胞核内移的现象。3、衰老大鼠体内抗氧化酶含量下降,氧化损伤增加,通过运动干预后能够显著性提高骨骼肌细胞抗氧化能力。4、衰老大鼠骨骼肌细胞凋亡率增加,通过两种不同形式运动干预(自由转轮和爬梯运动)都可以明显减少老年大鼠的过度细胞凋亡。5、运动干预可以增加老年大鼠骨骼肌能量代谢,激活细胞自噬,减少泛素蛋白酶体调控的蛋白降解,增加蛋白质的合成,对衰老性肌萎缩具有一定的康复作用。综上所述,运动干预能够通过调控蛋白质降解的主要途径,包括泛素蛋白酶体和自噬溶酶体,改善老年大鼠骨骼肌蛋白质代谢失衡的状态。本实验通过两种中等强度运动干预调控蛋白质降解改善衰老性肌萎缩,为老年人预防与治疗衰老性肌萎缩提供了新的干预研究思路。
[Abstract]:Objective: to construct an aging Myoatrophy model by naturally feeding SD rats to 21 month old, and to explore the effect of exercise intervention on the improvement of aging muscular atrophy by two moderate intensity exercise interventions (free rotation wheel and climbing ladder movement), and provide a theoretical basis for the rehabilitation of aging Myoatrophy. General fitness provides certain exercise intervention guidance. Methods: 19 SD male rats were fed to 21 month old to construct an aging muscular atrophy model, and 19 old rats were divided into the elderly control group (Senior Control Group, SC), and the elderly free rotation group (Senior Voluntary Wheel Running Group, SW) 6, the elderly climbing ladder group (Senior) Ing Group, SL) 7; at the same time, 10 3 month old adult rats were used as the young control group (Youth Control Group, YC). All four groups of rats were weighed, the gastrocnemius muscle was collected and weighed in 24 hours after 8 weeks of exercise intervention. The ratio of gastrocnemius wet weight and weight was calculated to evaluate the degree of muscle atrophy and to detect serum super. Superoxisome dismutase (SOD), malondialdehyde (Malonaldehyde, MDA) content to compare the antioxidant capacity of rats in each group; TUNEL staining was used to detect the rate of gastrocnemius apoptosis; protein immunoblotting was used to detect skeletal muscle energy metabolism, protein degradation and protein synthase expression. Results: 1) compared with the YC group, the gastrocnemius of group SC rats The wet weight ratio of muscle decreased significantly (p0.001). After exercise intervention, the wet weight ratio of rats in group SW and SL group was higher than that in group SC (P0.05).2). Compared with group YC, the serum SOD significantly decreased (p0.001) and MDA content increased significantly (P0.01) in the SC group, and the group had no significant difference but had no significant difference after exercise intervention. Rising trend.3) HE staining results showed that the muscle fibers of the gastrocnemius muscle of the SC group showed obvious atrophy of muscle fibers and the movement of the nuclei in the group of the group of YC, and the phenomenon was obviously improved after the exercise. At the same time, the gap between the gastrocnemius fibers in the SW and SL groups was reduced and the SL group was significantly thickened with.4) in the SL group. Compared with group YC, the apoptosis rate of gastrocnemius cells in group SC was significantly increased (p0.001). The apoptosis rate of gastrocnemius cells in old rats after exercise intervention was significantly decreased (P0.01).5). The expression of AMPK, Sirt1 and PGC-1 alpha in gastrocnemius muscle of group SC was down significantly down (p0.). 01) after exercise intervention, the energy metabolism in the gastrocnemius muscle of SW and SL rats increased significantly (P0.01) 6) through the detection of protein degradation pathway related protein expression in the gastrocnemius muscle of rats. Compared with the YC group, the level of autophagy decreased significantly in the SC group, and the LC3Atg7Beclin1 expression decreased significantly (P0.01), and the ubiquitin protease marker protein (Fox O3a/A). Trogin1) significantly increased expression (P0.05), autophagy pathway was activated after exercise intervention, and the expression of ubiquitin protease pathway related protein decreased. Conclusion: 1, the loss of muscle mass in the aging process, moderate intensity exercise intervention for aging muscle atrophy can play a certain rehabilitation effect.2, the skeletal muscle fibers of aging rats appear muscle fiber The decline in cross section area and the phenomenon of cell nuclear migration.3, the antioxidant enzyme content in the aged rats decreased and the oxidative damage increased. After the exercise intervention, the antioxidant capacity of skeletal muscle cells could be significantly increased, the apoptosis rate of skeletal muscle cells in old rats increased, and two different forms of exercise intervention (free rotation wheel and ladder movement) were available. In order to reduce the excessive apoptosis.5 in old rats, exercise intervention can increase the energy metabolism of skeletal muscle in old rats, activate autophagy, reduce the protein degradation by ubiquitin proteasome, increase the synthesis of protein, and have a certain recovery for aging muscle atrophy. In summary, the exercise intervention can regulate the protein by regulating the protein. The main methods of qualitative degradation, including ubiquitin proteasome and autophagosome, improve the state of protein metabolism imbalance in skeletal muscles of old rats. This experiment provides new intervention research ideas for the prevention and treatment of aging muscle atrophy by regulating protein degradation by two kinds of moderate intensity exercise intervention.
【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】：G804.2

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