Neuroserpin（NSP）是一种轴突选择性的神经源性丝氨酸蛋白酶抑制剂，在成人中枢神经系统有广泛表达，调节神经元迁移、突触形成，在神经元重塑与维持上起重要作用。在脑损伤时对神经相关细胞具有抑制凋亡的保护作用。但是其在低位中枢（脊髓）的作用尚无文献报道。外伤性脊髓损伤（TSCI）的治疗是全世界面临的重大难题，细胞凋亡在其中发挥了巨大作用。文献报告，自噬与凋亡密切相关，并可调控凋亡；我们的前期研究也发现NSP在TSCI后表达升高，给予外源性NSP后，损伤部位凋亡诱导蛋白Bax表达明显下降；Beclin-1基因表达随时间发生改变。由此我们提出假设：外源性NSP在TSCI后，对脊髓功能具有保护作用，并调控自噬而减少凋亡性细胞死亡。本研究通过观察NSP对TSCI的作用，并使用相关工作试剂，了解NSP对自噬的调控作用，探讨细胞内自噬－凋亡平衡可能的作用途径与机制，为NSP治疗TSCI提供理论基础

Neuroserpin (NSP), an axonally secreted serine protease inhibitor, is widely expressed in the adult central nervous system including spinal cord. It plays an important role in regulating migration, remodeling and maintenance of neurons, synapse formation, moreover it has the protective effect with inhibiting apoptosis of nervous cells in brain injury. But the function of NSP after spinal cord injury is still unknown. The treatment of traumatic spinal cord injury (TSCI) is a major challenge to the doctors all around of the world. Apoptosis, in secondary spinal cord injury, is critical for the function protection and recovery of spinal cord. It has been reported that autophagy is closely associated with apoptosis, and regulates the level of apoptosis. Our previous study demonstrated that the expression of NSP increased after TSCI, and the level of Bax, an apoptosis-inducing protein, significantly decreased with the administration of exogenous NSP. Additionally, the gene expression of Beclin-1 changed with time after using NSP in TSCI rat model. Thus, we hypothesize that exogenous NSP has the neuro-protective effect on spinal cord after TSCI, and can reduce apoptotic cell death by regulating autophagy. We will consider the regulatory role of NSP on autophagy after TSCI, and investigate the mechanism and pathway of the balance of autophagy and apoptosis by using some tools reagents. The study will provide the theoretical basis for the treatment of TSCI by NSP.