转录因子OLIG2调控遗传易感基因对先天性巨结肠的发病机制研究

先天性巨结肠（HSCR）是肠神经发育异常引发的复杂性遗传病。我们前期证实多个遗传基因,然而大部分机制未明。整合多组学数据提示OLIG2调控包括RET在内多个遗传基因介导的肠神经发育网络,与疾病的发生密切相关。OLIG2是神经外胚层祖细胞的重要调节因子,但在肠神经系统中的作用鲜有研究。斑马鱼模型证实OLIG2低表达导致肠神经发育不良,蠕动减缓,符合临床疾病特征;双荧光素酶报告实验进一步提示OLIG2转录水平上调控已知基因RET及新证基因ARHGEF4、ATXN1,其结合效率受遗传基因相应遗传变异影响。OLIG2如何调控下游遗传基因导致肠神经的发育异常继而引发疾病？本项目拟利用已建立的斑马鱼模型和肠神经元诱导分化体系明确OLIG2对特定遗传基因的调控在巨结肠发生中的作用机制。利用小鼠模型进行干细胞移植和干扰实验,证实靶向调节OLIG2及其下游调控基因对肠神经元修复作用，为疾病治疗提供新靶点。

Hirschsprung’s disease (HSCR) is a neurodevelopmental disorder characterized by the absence of nerves in intestine with strong genetic components. In the past decades, several genes were identified as associated with HSCR under unclear mechanism. Integrating transcriptome and genome wide association study（GWAS）results，OLIG2 is suggested to modulate six HSCR genetic susceptibility genes in transcriptional level which may affect enteric neural crest stem cells （ENCSC）development ending up with disease. OLIG2 is a basic helix-loop-helix (bHLH) transcription factor for astrocyte differentiation, with limited study with enteric nervous system (ENS). Based on the knockdown models of zebrafish, we found lower expression of OLIG2 lead to abnormality of ENS system and absence of parasympathetic intrinsic ganglion cells. Through public database, the binding sites of OLIG2 for the HSCR genes including RET, ARHGEF4 and ATXN1 were located in the disease associated variants, the risk alleles affected the binding affinity which may further affect the gene expression. According to the previous results: we raised a following question that how would OLIG2 modulate gene expression ended up with disease status? We propose to clarify the regulatory mechanism for OLIG2 together with the HSCR genetic associated genes using established human Induced Pluripotent Stem Cells （hiPSC）differentiation system and zebra fish model. HSCR mouse models will also be adopted to identify the detailed regulatory roles of OLIG2 and the downstream regulated HSCR associated genes by stem cell transplantation and interference experiments. These findings would help us to explore novel disease-related mechanism and find potential new drug target.