内源性UTI缺乏对EAE模型少突胶质细胞凋亡及其细胞内p75NTR/proNGF信号通路的影响

多发性硬化（MS）是一种中枢性脱髓鞘疾病，其致残率高，对社会影响大，但发病机制不明。我们前期研究发现MS患者脑脊液尿胰蛋白酶抑制剂（UTI）减少且与病残呈负相关；MS模型EAE脑内UTI表达减少且与EAE病残、OLG凋亡呈负相关；而外源性UTI治疗EAE后脑内p75NTR、proNGF表达、OLG凋亡均减少。因此，我们提出一种假说“内源性UTI缺乏敏化p75NTR/proNGF信号通路促进EAE中OLG凋亡”。为此，本项目拟在前期研究基础上，将UTI基因敲除鼠、野生型鼠分别诱导成EAE，从体内、外实验两个方面及整体、细胞、分子三个层次，采用特殊染色、细胞分离、分子生物学等技术，以p75NTR及其所介导的信号分子、胞内域结合蛋白表达及胞内酶活性等为指标，观察UTI缺乏对EAE中OLG凋亡及其凋亡通路的影响，以论证我们提出的假说，并揭示其中的分子机制，为进一步研究MS/EAE发病机制奠定基础。

Multiple sclerosis (MS) is a demyelinating disease in central nerve system, the mechanism is not clear. Our previous results indicated a reduced urinary trypsin inhibitor (UTI) level in cerebrospinal fluid of MS patients and the levels were associated with the severity of MS (Neurochemistry International 2015). Then our preliminary experiment data also showed that UTI expression was reduced and p75NTR expression was increased in brain tissue of experimental autoimmune encephalomyelitis (EAE, a model for multiple sclerosis) and negatively associated with disease disability and number of apoptotic OLGs. While we also found UTI protected against EAE through reduction of OLGs apoptosis by decreasing p75NTR and proNGF expression (Neurochemical Research 2011). As a result, we put forward a hypothesis that UTI deficiency sensitizes p75NTR/proNGF mediated apoptosis of oligodendrocytes in EAE. To demonstrate the hypothesis, we will use specific stain, isolation of cells, molecular biological technology to observe that UTI deficiency influence on OLG apoptosis and the apoptosis pathway on the body, cell and molecular levels in EAE which separately induced UTI gene knockout mice and wildtype mice, with myelin proteins, p75NTR mediated apoptosis signal molecule proteins, cellular domain binding protein expression and cellular enzyme activity of OLGs as indicators. It is supposed to provide basis for further study on the pathogenesis of MS/EAE.