Emx2在大鼠脊髓损伤后内源神经干细胞激活和向神经元分化中的作用研究

Activation and differentiation of neural stem cells (NSCs) play important roles on functional recovery after spinal cord injury (SCI). In this field, how to promote spinal cord NSCs activation and differentiation into neurons is an important topic. According to previous reports, Emx2 is critical for brain NSC proliferation and development of hippocampus; however, it is not clear about the roles of Emx2 on spinal cord NSCs during proliferation and differentiation. Our preliminary results showed that Emx2 overexpression in spinal cord NSCs of rats promoted cell proliferation as well as the efficiency of differentiation into neurons. In addition, expression of Emx2 decreased during the differentiation process of spinal cord NSCs. RNA-Seq showed that expression of Emx2 increased 3 days after SCI, and that activation of the spinal cord NSCs was enhanced. In this proposal, we will establish complete thoracic SCI rat models and employ techniques such as RNA-Seq, QPCR, western blot and immunofluorescence to investigate the expression patterns of Emx2 and the roles of Emx2 in spinal cord NSC activation and differentiation after SCI. The proposed study may offer a new solution for SCI treatment.

脊髓损伤后神经干细胞的激活及分化对于损伤后功能修复具有重要作用。如何促进损伤后神经干细胞激活及促进向神经元分化是本领域的重要课题。根据文献报道，Emx2对脑神经干细胞的增殖及脑海马区的发育发挥重要作用，而对脊髓神经干细胞增殖和分化的作用目前尚未清楚。我们前期结果发现，在大鼠脊髓神经干细胞中过表达Emx2可以促进其增殖，且向神经元分化的效率也得到提高。此外，Emx2的表达在脊髓神经干细胞分化过程中降低。RNA-Seq指出脊髓损伤3天后，即神经干细胞激活上升期，Emx2的表达升高。我们推测Emx2对脊髓神经干细胞的增殖可能具有促进作用，对神经干细胞的分化也可能发挥重要作用。本研究中我们制作大鼠胸段脊髓全横断模型，采用RNA-Seq、QPCR、Western Blot、免疫荧光等技术，阐明Emx2在脊髓损伤后的表达模式和对脊髓损伤后神经干细胞的激活和分化等的作用，为脊髓损伤治疗提供了新思路。

本项目在良好的研究基础上，结合查阅文献，对Emx2在脊髓损伤后神经干细胞的激活及分化中的作用进行了细致研究，揭示了Emx2在此过程中的重要作用，课题前期工作基础发现，在大鼠脊髓神经干细胞中过表达Emx2可以促进其增殖，且向神经元分化的效率也得到提高，提示Emx2可能在此过程中发挥作用。在此工作基础上，本课题增加了脑神经干细胞作为对照，体外通过在脑神经干细胞敲降Emx2及在脊髓神经干细胞中过表达Emx2，体内通过慢病毒注射大鼠全横断胸段脊髓，采用免疫荧光、RNA-Seq、QPCR、Western Blot等技术，阐明Emx2可能对脊髓损伤后神经干细胞的激活和分化等有促进作用，并作出Emx2互作蛋白网络，为脊髓损伤治疗及Emx2的作用机制提供了新思路。