胞浆Olig1与Tubulin相互作用调控少突胶质细胞突起生长的机制研究

To understand the mechanism of oligodendrocyte differentiation and maturation is significantly important for remyelination process. We recently found that cytoplasmic Olig1 associated with the cell processes outgrowth in premature (or mature) oligodendrocytes. Based on this observation, our proposed investigation will focus on the effect and mechanism by which phosphorylated Olig1 regulates Tubulin polymerization and then promotes cell processes outgrowth. Applying OPC cultures, Olig1 knockout mice as well as Cuprizone-induced demyelination mice models, we will: (1) To examine the interaction and co-localization of Olig1 with Tubulin in the process of differentiation and remyelination. (2) To map the binding domain of them and identify the critical modification affecting their interaction. (3) To validate Olig1 as a key promoter on the maturation and remyelination process via promoting tubulin polymerization. Finally we want to prove our hypothesis that phosphorylated Olig1 in cytosol enhances the interaction with Tubulin to promote polymerization and advance the processes outgrowth in early development. Our study may not only demonstrate the new function of Olig1 in manipulate the processes outgrowth of OL, but also provide a new insight into the mechanism of oligodendrocyte differentiation which benefits a novel strategy for remyelination and a potential target for drug screening.

少突胶质细胞（OL）分化调控机制的研究对促进髓鞘再生意义重大。我们最新研究发现胞浆定位Olig1与细胞突起生长密切相关。以此为基础，本课题将进一步探讨磷酸化修饰的Olig1在调控Tubulin聚合，促进少突胶质细胞突起生长中的作用和机制。利用原代OPC培养、Olig1敲基因小鼠和脱髓鞘模型：（1）明确Olig1与Tubulin的共定位及相互结合与突起生长的关系；（2）鉴定Olig1与Tubulin的结合区域及区域内关键修饰位点；（3）验证Olig1与Tubulin的结合在髓鞘形成、再生中的作用。最终证明胞浆中的Olig1通过特异区域中磷酸化修饰，加强其与Tubulin的结合，促进微管聚合，进而促进早期分化细胞的突起生长。该课题的完成不仅有助于发现Olig1调控OL突起生长的新功能，也可阐明OL形态分化成熟的新调控机制，为促进OL发育成熟的策略研究和后续药物靶标的选择提供新的基础资料。

本课题以研究少突胶质细胞分化的调整机制为目标，发现了转录因子Olig1在胞浆中具有转录调控之外，具有促进细胞突起生长新功能，且磷酸化修饰可能参与调控Olig1与的Tubulin聚合。结果如下：（1） OPC发育及髓鞘形成过程中，Olig1与Tubulin共定位表达及相互结合；（2）Olig1与Tubulin结合区域内关键性修饰位点的磷酸化修饰使Olig1更多地与Tubulin结合，并与细胞突起生长密切相关；(3)证明了Wnt信号通路对OPC分化的抑制作用，而阿司匹林可以通过抑制Wnt通路而促进OPC分化和突起生长；（4）在OPC分化和突起生长中也关注了能量物质的摄取途径，发现OPC通过Cx介导的通道来获得大量的葡萄糖供应。该课题的完成不仅有助于从基因转录调控之外，认识少突胶质细胞成熟分化调控机制，也可望阐明OPC突起生长、髓鞘形成的关键性调节途径，丰富对Olig1功能的认识，为促进少突胶质细胞分化成熟的策略研究和后续药物筛选靶标的选择提供新的基础资料。该课题结果目前发表论文4篇，其中SCI论文3篇，中文核心期刊论文1篇；参与培养在读博士研究生1名，毕业硕士研究生1名。