冬眠达乌尔黄鼠骨骼肌中调节PI3K/AKT/mTOR的MicroRNAs的表达水平的研究

发布时间：2022-08-29 19:00

　　对于哺乳动物而言,在去负荷和高应激压力条件下,如长期不活动、卧床、失重、缺氧和低温等,较易发生骨骼肌萎缩和肌肉质量减少。然而,同样处于长期不活动叠加低体温等高应激条件下的冬眠哺乳动物,特别是小型冬眠哺乳动物,在历经长达数月的冬眠不活动期后,没有或仅有很小程度的肌肉萎缩和肌肉质量的降低。在冬眠长时间不活动状态下,小型冬眠哺乳动物通过何种机制避免了肌肉萎缩的发生?对此机制的探讨不仅可为冬眠动物的生理适应机制增加新的有价值的科学资料,还有望为人类废用性肌萎缩的防治提供新思路。关于骨骼肌萎缩的发生机制,一般认为,骨骼肌细胞中蛋白质合成过程受到抑制,而蛋白质降解过程得以增强,导致肌肉细胞蛋白质含量减少,这是导致肌肉萎缩和肌肉质量减少的主要原因和表现。PI3K/AKT/mTOR信号通路在调节细胞周期中起着至关重要的作用,在调节胞内蛋白质合成方面亦扮演着重要的角色。mTOR通过调节骨骼肌合成代谢与分解代谢的信号传导,可以控制骨骼肌的肥大与萎缩。已有的研究和我们之前的成果已经证实,mTOR在维持冬眠动物骨骼肌质量中具有重要作用。因此,通过对PI3K/AKT/mTOR信号通路活性的调节,实现肌细胞内蛋白... 

【文章页数】：66 页

【学位级别】：硕士

【文章目录】：
中文摘要
ABSTRACT
ABBREVIATIONS
CHAPTER1 Background
    1.1 Mammalian hibernation
    1.2 The changes in mammalian skeletal muscle during hibernation
    1.3 The MicroRNAs and its functions
        1.3.1 The discovery of miRNAs
        1.3.2 Introduction to miRNAs in hibernation
    1.4 The PI3K/AKT/mTOR pathway and its functions
    1.5 Study progress of miRNAs on PI3K/AKT/mTOR pathway in skeletal muscle
    1.6 Purpose and significance of present study
CHAPTER2 The changes of body mass and muscle mass of Daurian ground squirrels
    2.1 Daurian ground squirrels in present study
    2.2 The monitoring and grouping of Daurian ground squirrels
        2.2.1 Body temperature monitoring
        2.2.2 Experimental animal grouping
    2.3 Skeletal muscle sample collection
        2.3.1 Selection of semitendinosus muscle for present study
        2.3.2 Animal anesthesia
        2.3.3 Isolation of ST muscle
        2.3.4 The changes of body mass of Daurian ground squirrels
        2.3.5 The changes of ST muscle mass
    2.4 Brief summary
CHAPTER3 The expression levels of four miRNAs in ST muscle
    3.1 Selection of miRNAs
        3.1.1miR-206
        3.1.2miR-29b
        3.1.3miR-21a
        3.1.4miR-99b
    3.2 Experimental methods
        3.2.1 Identifying the miRNAs sequence
        3.2.2 Primer designing
        3.2.3 Main instruments and reagents
        3.2.4 Extraction of miRNAs from ST muscle
        3.2.5 cDNA synthesis from miRNA
        3.2.6 Real time-PCR detection of miRNAs
        3.2.7 Data statistics and analysis
    3.3 Experimental results
        3.3.1 The expression levels of miR-206 in ST muscle in different periods
        3.3.2 The expression levels of miR-29b in ST muscle in different periods
        3.3.3 The expression levels of miR-21a in ST muscle in different periods
        3.3.4 The expression levels of miR-99b in ST muscle in different periods
    3.4 Brief summary
CHAPTER4 The expression levels of PI3K/AKT/mTOR in ST muscle
    4.1 The PI3K/AKT/mTOR signaling pathway
    4.2 Experimental methods
        4.2.1 Main instruments and reagents
        4.2.2 The formulations of solutions
        4.2.3 Extraction of protein from ST muscle
        4.2.4 Western Blotting
        4.2.5 Data statistics and analysis
    4.3 Experimental results
        4.3.1 The expression levels of PI3K in ST muscle in different periods
        4.3.2 The expression levels of AKT in ST muscle in different periods
        4.3.3 The expression levels of mTOR in ST muscle in different periods
    4.4 Brief summary
CHAPTER5 Discussion and conclusion
    5.1 Discussion
    5.2 Conclusion
REFERENCES
ACKNOWLEDGEMENTS
Research achievements during the study for the Master’s degree



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