基因沉默NMII工程化调节生长锥促进脊髓损伤修复的相关研究

脊髓损伤的治疗至今仍是医学界的难题,提高神经元轴突的再生能力是促进脊髓损伤后神经功能恢复的关键。目前研究发现，微管及肌动蛋白作为生长锥的骨架结构,在轴突生长中起着导向作用，生长锥既是促进轴突生长的机械靶点也是调节轴突生长集中的信号靶点,其中RhoA/Rock通路对生长锥骨架结构起着调节作用，NMII作为此通路下游的主要蛋白,在工程化调节生长锥结构促进轴突再生中起着重要作用，抑制NMII可机械性调节微管及肌动蛋白结构，恢复生长锥对轴突延伸的导向作用,从而明显提高轴突再生能力。因此本课题拟探索脊髓损伤后，NMII激活态含量与生长锥塌陷率及轴突凋亡的相关性；同时采用RNAi技术结合第三代慢病毒载体沉默NMII，通过体内外联合实验探索抑制NMII对生长锥骨架结构的工程化调节作用，观察其促进轴突再生及脊髓损伤后功能恢复的情况，为其应用于脊髓损伤修复提供实验证据。

Spinal cord injury is still a difficult medical problem until now.How to enhance the regeneration capacity of neuronal axon is the key point to promote functional recovery after spinal cord injury. Recent studies have showed that microtubule and actin constitute the cytoskeleton of growth cone, and the growth cone plays a guiding role in the growth of axon. Moreover, the growth cone is the mechanical target and signal target in driving axon extension. Among the signal pathways, the RhoA/Rock pathway plays an important role in regulating the cytoskeleton of growth cone. NMII is the main protein placed downstream of RhoA/Rock signalling pathway, and NMII can engineer the cytoskeleton of growth cone to promote axon regeneration. NMII inhibition can mechanically regulate the structure of microtubule and actin and rehabilitate the guiding function of growth cone in axon extension. Consequently, the first objective of this project is to study the connection between activated NMII content and the rate of growth cone collapse after spinal cord injury. The second objective is to verify the effect of gene silencing NMII on promoting axon regeneration in vitro and vivo experiments and evaluate the effect of promoting functional recovery after spinal cord injury in Wistar rats. It is expected that this project can provide intuitionistic evidences in treating spinal cord injury by gene therapy.