FUT8催化L1CAM岩藻糖化修饰抑制整合素受体信号通路在先天性巨结肠发病机制中的研究

肠神经嵴细胞迁移障碍是先天性巨结肠（HSCR）发病的重要病因，最新研究发现糖基化修饰参与细胞迁移过程。前期已证明糖基化蛋白异常会影响肠神经发育。预实验提示：患儿肠组织岩藻糖基转移酶FUT8高表达，且岩藻糖修饰水平升高；过表达FUT8斑马鱼模型表现出肠神经缺失的疾病病理特征；IP-MS进一步证实神经黏附因子L1CAM是FUT8的催化底物，且与整合素受体信号通路关键因子存在共表达关系。文献报道该通路与肠神经嵴迁移密切相关。据此提出：FUT8催化L1CAM岩藻糖化修饰抑制整合素信号通路，阻碍肠神经嵴迁移的假说。本项目拟：1.通过检测FUT8过表达、酶活突变、L1CAM修饰位点突变等不同细胞系的L1CAM岩藻糖化水平和迁移能力，验证FUT8是否通过L1CAM岩藻糖化而影响迁移功能；2.通过检测整合素信号关键因子，明确岩藻糖化L1CAM阻碍肠神经嵴迁移的分子通路，为疾病修饰水平上的致病机理提供依据。

Enteric neural crest cell migration disorder is an important factor in Hirschsprung's Disease (HSCR), and recent studies have found that glycosylation is involved in cell migration. We found that the expression of fucosyltransferase fut8 was high in colon tissue of children with HSCR, and the level of fucose modification was increased, and zebrafish model with over expression of fut8 showed the same phenotype of enteric nerve loss and peristalsis reduction as HSCR. IP-MS neural adhesion factor L1CAM is the catalytic substrate of fut8 and co-expressed with the key factors of integrin receptor signaling pathway. It has been reported that this pathway is closely related to the migration of enteric neural crest. Based on this, we propose that fut8 promotes fucosylation, L1CAM regulates integrin receptor signaling pathway and blocks neural crest migration. We plan to carry out the following research: 1. Construct three cell lines with fut8 overexpression, fut 8 enzyme activity mutation and L1CAM modification site mutation respectively, detect fucosylation modification level and migration of the cell, and prove the interaction between fut8 and L1CAM; 2. Detect integrin signaling pathway and prove that fucosylated L1CAM was pathogenic through this pathway. This study provided the basis for the pathogenic mechanism at the level of disease modification.