雪旺细胞外泌体介导PTEN/AKT/mTOR信号通路修复脊髓损伤后肌萎缩的实验研究

Muscle atrophy is a common complication after spinal cord injury, seriously affecting the quality of life and rehabilitation of patients. Previous study found that a variety of key proteins in the muscles were changed in the early stage of spinal cord injury, but there is lacking early interventions for muscle atrophy after spinal cord injury currently. Schwann cells transplantation could improve a variety of neuropathological conditions, which was confirmed in early work, and exosomes was the potential mechanism. Accordingly, the research group proposed the hypothesis that Schwann cells repair muscle atrophy after spinal cord injury through the exosomes. The research group aim to study the effects and molecular basis of Schwann cells exosomes on the proliferation, differentiation of muscle cells, and anti-atrophy through the construction of co-culture system of Schwann cells and muscle cells; to observe the role of Schwann cells exosomes in key molecules, cells and tissues and physiological functions of the muscles after spinal cord injury through vivo transplantation; to explore whether Schwann cells exosomes can repair the muscle atrophy after spinal cord injury by regulating PTEN/AKT/mTOR signaling pathway through double luciferase reporter vector system and gene overexpression and knockdown techniques. This study will provide safer and more effective repair strategies and new theoretical basis for muscle atrophy after spinal cord injury, and creates chance of early rehabilitation and effective repair for spinal cord injury.

肌萎缩是脊髓损伤后常见并发症，严重影响患者生活质量和康复效果。前期研究表明，肌肉中多种关键蛋白在脊髓损伤早期即发生明显改变，但目前临床缺乏早期干预脊髓损伤后肌萎缩的手段。雪旺细胞移植可以改善多种神经病理状态，而雪旺细胞通过分泌外泌体发挥其作用。据此，课题组提出雪旺细胞外泌体修复脊髓损伤后肌萎缩的科学假说。本课题拟构建雪旺细胞外泌体和肌细胞体外共培养系统，探索雪旺细胞外泌体对肌细胞增殖、分化作用及抗萎缩的修复效果；构建大鼠脊髓损伤模型，明确体内移植雪旺细胞外泌体对脊髓损伤后肌萎缩在分子-细胞-组织-生理功能层面的修复作用；通过双荧光素酶报告载体系统及基因过表达和敲减技术，研究雪旺细胞外泌体介导PTEN/AKT/mTOR信号通路修复脊髓损伤后肌萎缩的可能机制，本研究将为脊髓损伤后肌萎缩提供更加安全、有效的修复策略和新的理论基础，为实现脊髓损伤的早期康复和有效修复创造条件。

肌萎缩是脊髓损伤后常见并发症，严重影响患者生活质量和康复效果。本课题组前期研究表明，肌肉中多种关键蛋白在脊髓损伤早期即发生明显改变，但目前临床缺乏早期干预脊髓损伤后肌萎缩的手段。雪旺细胞移植可以改善多种神经病理状态，而雪旺细胞通过分泌外泌体发挥其作用。据此，课题组通过构建构建雪旺细胞外泌体和肌细胞体外共培养系统，发现雪旺细胞外泌体对肌细胞增殖、分化作用及抗萎缩都具有良好的修复效果；在大鼠脊髓损伤模型中，本课题组验证了雪旺细胞外泌体对于脊髓损伤后肌萎缩在分子-细胞-组织-生理功能层面具有良好的修复效果；随后本课题组通过双荧光素酶报告系统验证了miR-206可以负性调节PTEN基因表达，并且通过过表达和敲除miR-206的质粒和慢病毒，在细胞和组织层面上研究了雪旺细胞外泌体通过PTEN/AKT/mTOR信号通路修复脊髓损伤后肌萎缩。本研究为脊髓损伤后肌萎缩提供更加安全、有效的修复策略和新的理论基础，为实现脊髓损伤的早期康复和有效修复创造条件。