HOXB13调控骶神经嵴细胞发育与迁移的作用机理及在先天性巨结肠发生中的分子机制

先天性巨结肠（HSCR）是由于肠神经嵴细胞发育及迁移障碍导致的肠神经节缺失病变。骶神经嵴细胞（SNCC）是肠神经嵴主要来源之一，从尾侧向头侧迁移并分化为肠神经元（EN）。80%HSCR仅累及乙状结肠和直肠，与SNCC定植区域重合，但由于缺乏SNCC体外分化模型，其在HSCR发生发展中扮演的角色远未阐明。申请人前期建立了人多能干细胞经SNCC分化为功能性EN诱导体系，证实SNCC可在无神经节后肠迁移并分化为EN。表达谱测序发现SNCC高表达HOXB13，敲低其表达显著影响SNCC的迁移及EN的分化；那么HOXB13是如何调控SNCC发育、迁移、分化并参与HSCR病理发生？本研究拟利用SNCC构建含EN结肠类器官，系统解析HOXB13在SNCC形成与分化中的调控网络，阐明HOXB13突变导致的SNCC发育障碍与HSCR发生的关系，为揭示HSCR的致病机理，探索细胞替代治疗提供新思路。

Hirschsprung disease (HSCR) is aganglionosis of the intestine caused by the development and migration defects of enteric neural crest cells. Sacral neural crest cells (SNCC) serve as one of the major source of enteric neural crest cells, migrating along the colorectum in a caudal-to-rostral direction and differentiating into enteric neurons (EN). In the majority of HSCR cases (80%), the aganglionic tract involves the rectum and the sigmoid colon only (short segment HSCR), which coincide with the colonization area of SNCC, but the role of SNCC in HSCR are poorly understood due to lack of SNCC differentiation model in vitro. The applicant previously established an efficient differentiation system for inducing human pluripotent stem cells to differentiate to functional EN via the intermediate stage of SNCC, which can migrate and colonize the aneural mouse hindgut. The RNA-Seq, QPCR and immunofluorescence staining assays demonstrated that SNCC highly expressed HOXB13. Further research proved that knocking down HOXB13 significantly affected proliferation and EN differentiation properties of SNCC. Then, How HOXB13 regulates SNCC development, migration, differentiation and participates in HSCR pathogenesis? Our group plan to systematically analyze the regulatory network of HOXB13 in the formation and differentiation of SNCC and elucidate the relationship between SNCC developmental disorder caused by HOXB13 mutation and the occurrence of HSCR using colonic organoids containing EN. Our results may provide new insights for revealing the HSCR pathogenesis and exploring cell therapy of HSCR.