Mechanisms of modifier effects on aganglionosis in the Sox10Dom model of HSCR

描述(申请人提供)：先天性巨结肠症(HSCR)是一种先天性胃肠道疾病，表现为远端结肠的可变部分缺乏神经节，原因是神经脊干细胞(NCSC)缺陷，导致肠道神经系统。HSCR是一种复杂遗传病的典型例子。HSCR病例通常被归因于RET的突变，但包括Sox10在内的其他基因的突变也可能导致无神经节细胞增多症。大约50%的HSCR病例的病因不明。无神经节细胞增多症的程度在个体之间差异很大，甚至在家庭成员之间也有差异。对HSCR小鼠模型的研究表明，遗传背景中的修饰基因在决定无神经节细胞缺乏症的外显性和严重性方面发挥着重要作用。了解导致HSCR变异的修饰物和基因-基因相互作用将增加对HSCR复杂性和发病机制的理解。以前的研究已经确定了Sox10Dom小鼠在HSCR研究中的应用。这些小鼠概括了在患者中看到的无神经节细胞增多症，并已被用于识别无神经节细胞增多症的修饰物。本研究旨在证明Sox10与一个高度显著的候选基因的相互作用对Sox10Dom HSCR模型的无神经节细胞表型的影响，并确定这种相互作用对肠道NCSC的生物学效应。目的1将利用BAG修饰技术和转基因小鼠品系的产生来证明，已确定的候选基因的改变水平改变了Sox10Dom无神经节细胞症的外显率和严重程度。目的2采用免疫组织化学和培养纯化的神经干细胞，以确定修饰相互作用对神经干细胞迁移、增殖和发育潜能的影响。这项研究的结果将使胃肠病学界更好地了解HCSR的原因以及涉及肠道神经系统发育的生物过程。最后，对Sox10-修饰物相互作用的表征将提供对修饰物如何影响其他复杂疾病的洞察。这项研究将增加我们对HSCR遗传基础的理解，有助于确定患有不可分类疾病的患者的无神经节细胞增多症的原因，并增加对肠道神经系统发育的知识。

DESCRIPTION (provided by applicant): Hirschsprung disease (HSCR) is a congenital disorder of the gastrointestinal tract that presents as a lack of ganglia in a variable portion of the distal colon due to deficits in the neural crest stem cells (NCSC) that give rise to the enteric nervous system. HSCR is a prime example of a complex genetic disease. Often HSCR cases are attributed to mutations in RET but mutations in other genes, including SOX10, can also cause aganglionosis. Approximately 50% of HSCR cases are of unknown etiology. Extent of aganglionosis varies widely among individuals and can even differ between family members. Studies in mouse models of HSCR demonstrate that modifier genes in the genetic background play a large role in determining both the penetrance and severity of aganglionosis. Understanding modifiers and gene-gene interactions that contribute to variation of HSCR will increase understanding of HSCR complexity and pathogenesis. Previous studies have established the utility of Sox10Dom mice in the study of HSCR. These mice recapitulate the aganglionosis seen in patients and have been used to identify modifiers of aganglionosis. The current study aims to demonstrate the interaction of a highly significant candidate gene with Sox10 to impact the aganglionic phenotype of the Sox10Dom HSCR model and will definite the biological effect of this interaction on enteric NCSC. Aim 1 will use BAG modification techniques and the generation of transgenic lines of mice to demonstrate that altered levels of the identified candidate gene modify the penetrance and severity of Sox10Dom aganglionosis. Aim 2 will use both immunohistochemistry and culture of purified NCSC to determine the effect of the modifying interaction on migration, proliferation, and developmental potential on NCSC. The results of this study will provide the gastroenterology community with a greater understanding of the causes of HCSR as well as the biological processes involved in the development of the enteric nervous system. Finally, characterization of the Sox10-modifier interaction will provide insight into how modifiers influence other complex diseases. This research will increase our understanding of the genetic basis of HSCR, help identify causes of aganglionosis in patients with non-classifiable disease, and increase knowledge of enteric nervous system development.