神经中间丝蛋白alpha-internexin与细胞型朊蛋白的相互作用及其对神经元凋亡的影响机制研究

The neuropathology of prion disease is characterized by spongiform degeneration , the appearance and accumulation in the central nervous system of PrPsc, gliosis, and neuronal loss. It is reported that since PrP undergoes a profound structural transition during prion propagation, itseems likely that other proteins such as chaperones participate in this process. In our previous study, we found that alpha-internexin (INA) expression was up-regulated in brain of mice of prion disease, but down regulated in brain of control mice. It indicates that INA might play important role in pathogenesis of prion disease. Sufficient evidence shows that over-expression of INA leads to neurodegeneration in mouse. However, the role of INA in prion disease was poorly understood. There is little report regarding the interaction of INA and cellular prion protein (PrPc) in prion disease. In this study, we will investige whether INA interact with PrPc by immunofluorescence and co-immunoprecipitation, then determine the site of interaction by yeast two-hybrid system. The neurons isolated from the brain of PrP-/- and wild type mice, were transfected with pdRFP-alpha-internexin. Expression of molecules in apoptosis signal transduction will be observed during alpha-internexin interact with PrPc. We hope that this study will reveal the mechanism of neuron loss in prion disease and pave the way for mechanism of prion disease.

朊蛋白病(PD)病理特征是神经元空泡样变性、PrPSc聚集、胶质细胞增生以及神经元丧失。研究表明，除朊蛋白在其发病过程中起着重要作用外，还存在着其他某种蛋白的协同作用。我们前期研究发现alpha-internexin(INA)在PD模型鼠脑组织中高表达，在对照则为低表达。提示INA可能在PD发病过程中起重要作用。有研究表明INA过表达可导致神经元退行性改变的发生。但INA在PD病理变化中的角色还不清楚，尤其与细胞型朊蛋白（PrPc）的相互作用未见报道。为此，我们通过免疫荧光、免疫共沉淀的方法观察PrPc与INA是否存在相互作用，通过酵母双杂交的方法确定互作位点。通过分离PrP-/-和野生型小鼠神经元，过表达INA，观察互作后神经元凋亡通路的改变，以期能够从中发现朊蛋白病神经元丧失的机制，为深入探讨朊病毒病的致病机制奠定基础。