内源性多肽PDCAP在先天性巨结肠发生中拮抗神经嵴细胞迁移障碍的作用

Hirschsprung’s disease (HSCR) is characterised by the defect in the migration of enteric neural crest-derived cells (ENCCs), but little is known about the underlying mechanisms. Previous studies show that endogenous polypeptide PDCAP promotes nerve cell migration by binding to the lipid raft protein flotillin-1, while its precursor protein CAP also binds to flotillin-1 and recruits the focal adhesion protein vinculin to the lipid rafts, and then inhibits nerve cell migration. In addition, PDCAP arises from the structural domain where CAP binds to flotillin-1. Thus we hypothesized that CAP inhibits the depolymerization of focal adhesion by binding to flotillin-1 and recruiting vinculin to the lipid rafts, leading to the migration defect of ENCCs, which is how it participates in the pathogenesis of HSCR, while PDCAP competitively binds to flotillin-1 and inhibits CAP/vinculin functions, and eventually rescues the migration defect of ENCCs. .This project will investigate the mechanism by which CAP inhibits neural-crest-derived cells migration and study the antagonistic effect of PDCAP on this inhibition, and also assess its potential effect as a treatment for HSCR. This research can provide new insights into understanding the pathogenesis of HSCR and new thoughts on treatments during the embryonic period.

先天性巨结肠（HSCR）发生主要原因是肠神经嵴细胞（ENCCs）迁移障碍，但具体机制不清。前期研究发现内源性多肽PDCAP与脂筏蛋白flotillin-1结合促进神经细胞迁移，其前体蛋白CAP也与flotillin-1结合招募黏着斑蛋白vinculin到脂筏，抑制神经细胞迁移，且PDCAP来源于CAP与flotillin-1结合的结构域。由此假设：CAP通过与flotillin-1结合招募vinculin锚定到脂筏，抑制黏着斑解聚，导致神经嵴细胞迁移障碍，参与HSCR发生，而PDCAP与CAP竞争性结合flotillin-1，抑制CAP/vinculin的功能，拮抗神经嵴细胞迁移障碍。.本项目将探讨CAP抑制神经嵴细胞迁移的机制，研究PDCAP拮抗CAP导致神经嵴细胞迁移功能障碍的作用，评估PDCAP对先天性巨结肠的潜在治疗作用。本研究可为HSCR发生机制提供新视点和胚胎期治疗提供新思路。

先天性巨结肠（Hirschsprung disease, HSCR）发生的主要原因是肠神经嵴细胞（Enteric neural crest cells, ENCCs）迁移障碍，但具体机制不清。本项目基于HSCR内源性多肽质谱分析结果，首次发现来源于前体蛋白CAP结构域的内源性多肽PDCAP（Peptide derived from CAP），可以拮抗CAP导致的肠神经细胞迁移障碍，从临床样本、神经细胞、CAP小鼠模型等多方面对内源性多肽PDCAP拮抗CAP引起的ENCCs迁移障碍的具体机制进行了深入研究。研究结果证实CAP通过其Sorbin-homology结构域与脂筏蛋白flotillin-1结合，随后利用其SH3结构域招募黏着斑蛋白vinculin锚定到脂筏，抑制黏着斑解聚，降低ERK1/2的磷酸化水平，导致肠神经嵴细胞迁移障碍。而内源性多肽PDCAP可通过与其前体蛋白CAP竞争性结合flotillin-1，缓解CAP/vinculin通路对肠神经嵴细胞迁移的抑制。.在体外和在体实验层面，采用肠神经前体细胞（Enteric neural precursor cell, ENPC）、斑马鱼、EDNRB-/-先天性巨结肠小鼠模型探讨内源性多肽PDCAP对先天性巨结肠的治疗潜力，发现PDCAP可以拮抗前体蛋白CAP对ENPC细胞及斑马鱼肠神经系统的损害，并能部分缓解EDNRB缺失小鼠肠神经系统的发育障碍，对先天性巨结肠的胚胎期干预具有一定的治疗潜力。.本项目充分探讨了CAP抑制肠神经嵴细胞迁移的机制，证实PDCAP拮抗CAP导致肠神经嵴细胞迁移功能障碍的作用，评估PDCAP对先天性巨结肠的潜在治疗作用。本研究可为HSCR发生机制提供新视点，并为HSCR的胚胎期治疗提供新思路。