α-synuclein介导synaptotagmin7调控神经-肌肉接头突触前囊泡释放在帕金森病肌萎缩中的作用及机制研究

帕金森病(PD)肌萎缩降低患者生活质量，增加残疾和死亡风险。研究提示，PD关键致病性α-突触核蛋白(α-Syn)在神经肌肉接头(NMJs)聚集并抑制突触前囊泡释放引起肌萎缩，但其信号途径尚不清楚。我们前期利用RNA-Seq分析并确定了负调节囊泡释放的突触结合蛋白7(Syt7)在过表达人源α-Syn (mThy1-hSNCA)转基因小鼠肌肉中显著增加；激光共聚焦成像结果显示Syt7富集在NMJs突触前囊泡。综上，我们提出假设：α-Syn聚集介导Syt7抑制NMJs突触前囊泡释放导致肌萎缩。本项目拟利用mThy1-hSNCA小鼠和3D共培养NMJs细胞模型，借助免疫电镜、免疫共沉淀、Seahorse XF等技术，探讨α-Syn介导Syt7调控NMJs突触前囊泡释放在PD肌萎缩中的机制以及Syt7调控囊泡释放的运转模式。研究成果将丰富对PD肌萎缩机制的认识，为选择潜在治疗靶点提供实验依据。

Parkinson's disease (PD) muscle atrophy reduces the quality of life of patients and increases the risk of disability and death. Studies have suggested that the key pathogenic α-synuclein (α-Syn) of PD accumulates at neuromuscular junctions (NMJs) and inhibits the release of presynaptic vesicles to cause muscle atrophy, however, its signaling pathway is still unclear. In our previous study, RNA-Seq was used to analyze and determine the protein that negatively regulates the release of vesicles, synaptotagmin 7 (Syt7), was increased in the skeletal muscles of mice with human-α-Syn over-expressed (mThy1-hSNCA). The results of confocal laser imaging showed that Syt7 was enriched in presynaptic vesicles. In summary, we propose the hypothesis that α-Syn aggregation mediates Syt7's inhibition of NMJs presynaptic vesicle release signaling pathway, leading to muscle atrophy. This project intends to use mThy1-hSNCA transgenic mice, 3D co-culture NMJs cell model, with the help of immunoelectron microscopy, immunoprecipitation, Seahorse XF and other technologies, to explore the mechanism of α-Syn-mediated Syt7 regulation of NMJs presynaptic vesicle release in PD muscle atrophy and the operational mode of Syt7 regulating vesicle release. The research results will enrich the understanding of the mechanism of PD muscle atrophy and provide experimental basis for the selection of potential therapeutic targets.