针刺调控衰老性骨骼肌肌卫星细胞成肌分化及IGF-1/AKT通路的机制研究

Age-related skeletal muscle atrophy can reflect the degree of aging, and it's an important indicator for predicting aging and death.Myogenic differentiation ability of muscle satellite cells, regulation of skeletal muscle related mi-RNA as well as AKT/FOXO, AKT/mTOR signaling pathwaysinvolved in the synthesis and decomposition of muscle protein are the keyfactors of the repair, regeneration and hypertrophy of aging skeletal muscles.Based on the theory of "four limbs are the root" stated in Neijing(Inner Canon), we explore the anti-aging effect and mechanism of acupuncture fromthe viewpoint of skeletal muscle. Our previous study cooperated with Emory Universityof the U.S found obviously increased weight of atrophied muscles andsignificantly improved repairing level of muscle cells and related proteinexpression of laboratory mice, which suggest the good prospect of acupunctureprevention and treatment. Our current study will select natural aging rats asthe subjects and acupuncture as the intervention, to explore the comprehensivemechanism of acupuncture preventing, antagonizing or reversing the decrease of skeletal muscle during the aging process and improving the function of aging skeletal muscle by comparing the effects of acupuncture on skeletal muscle indifferent stages of adult and senescence through in vitro cell culture, immunofluorescence,Western blot and Real-time PCR, etc. so as to provide new preventing andtreating methods for anti-aging and improving the functions of skeletal muscle.

增龄性骨骼肌萎缩反映衰老的程度，是预测衰老死亡的一个重要指标。肌卫星细胞成肌分化能力，骨骼肌相关mi-RNA的调节与肌蛋白合成、降解有关的AKT/FOXO、AKT/mTOR信号通路，是衰老性骨骼肌修复、再生和肥大的关键因素。基于《内经》“清阳实四肢”、“四肢为本”学说，我们从骨骼肌入手探讨延缓衰老的效应及其机制。前期与美国Emory University合作研究表明，实验鼠萎缩的肌肉重量明显增加，肌细胞修复水平及相关蛋白表达显著改善，提示了针刺防治的良好前景。课题以自然衰老大鼠为研究对象，采用针刺干预手段，通过体外细胞培养、免疫荧光、Western blot、Real-time PCR等方法，对比针刺对成年期和衰老期不同阶段的骨骼肌效应，探讨针刺预防、拮抗或逆转衰老进程中骨骼肌减少、改善衰老性骨骼肌功能的综合机制，以期为延缓生命衰老、提升骨骼肌功能提供新的干预防治手段。

本课题在发现电针能够预防、延缓增龄性骨骼肌萎缩的基础上，结合分子生物学的研究方法，深入研究（1）预防性电针延缓大鼠骨骼肌萎缩的作用；（2）电针结合有氧运动延缓骨骼肌萎缩的作用；（3）老年期电针干预延缓骨骼肌萎缩的作用；（4）IGF-I/Akt通路参与电针延缓增龄性骨骼肌萎缩的作用机制研究。.研究结果表明：（1）电针“肾俞”、“足三里”能够延缓大鼠骨骼肌萎缩进程，增加肌肉湿重/体重比，维持一定功能活动；（2）不同时期、不同干预手段对于延缓大鼠骨骼肌萎缩的作用机制可能有一定差异；（3）预防性电针可上调骨骼肌IGF-1 mRNA表达水平和mTOR、P70S6K、MyoD、myogenin蛋白表达水平；（4）电针结合有氧运动可促进18月龄、20月龄自然衰老大鼠腓肠肌蛋白质合成，上调myogenin蛋白表达；（5）进入老年期，电针主要上调myogenin蛋白表达、抑制Myostatin蛋白表达，同时可降低泛素系统的Murf-1蛋白表达以及自噬溶酶体系统的Beclin-1蛋白表达；（6）电针能促进miR-1、miR-206、miR-133的表达，参与骨骼肌再生调控。纵观整个阶段研究，我们发现电针能够在一定程度上预防、延缓骨骼肌衰老，并提示电针对大鼠骨骼肌IGF-I/AKt通路有一定调节作用，有助于促进电针疗法在老年肌肉萎缩症中的应用，值得进一步研究。