Identifying Gli-Regulated Targets during Tracheal Development and Disease

项目总结/摘要 本项目的目标是确定Hedgehog/Gli信号调节气管的机制， 以及这一过程的中断如何导致围产期气管缺陷。气管错误 发育可能包括气管闭锁和气管食管（TE）裂，其中胎儿前肠管 不能正确分离，导致气管软骨形成受损导致气管软化。气管炎的病因 缺陷是知之甚少，需要新的诊断和治疗，以解决这些相对常见的 但可能致命的缺陷。人类患者外显子组测序以及小鼠突变模型已经开始 确定一些调节气管发育的发育途径，包括Hedgehog/Gli 通路例如，在鼠模型中，Gli 2和Gli 3的完全丧失导致气管插管的完全失败。 发育，而一些复合杂合Gli 2; Gli 3突变体表现出TE裂缝与气管软化。在 此外，我们的初步数据表明，Gli 3突变体的转基因表达，模拟遗传 在人类Pallister-Hall综合征患者中发现的病变也导致TE分离受损， 气管软骨缺失。 该项目的具体目标是识别发育中气管中的Gli靶基因，以确定Gli如何在气管中表达。 调节TE分离和气管软骨分化，并模拟人类气管的机制 缺陷对照和突变前肠的初步RNA-seq研究已经开始定义Gli靶点， TE开发。我将检验这些候选Gli靶基因被错误表达和/或 在Gli突变体的TE发育过程中错误定位。我们的初步进一步数据表明，Wnt和 BMP通路作用于HH/Gli的下游，我们将使用小鼠遗传学和胎儿前肠的组合， 培养来测试缺陷的Wnt和BMP信号传导是导致气管缺陷的假设。 软骨形成这些实验的结果将告知人类患者气管缺陷的基础 以及引导气管iPSC向新的治疗可能性分化。该项目将 还为这些患者提供当前临床诊断和治疗策略的宝贵培训。 !

Project Summary/Abstract This goal of this project is to identify the mechanisms by which Hedgehog/Gli signaling regulates tracheal development and how disruptions in this process can lead to perinatal tracheal defects. Errors in tracheal development may range from tracheal atresia and tracheoesophageal (TE) clefts, where the fetal foregut tube fails to separate properly, to tracheomalacia due to impaired tracheal chondrogenesis. The etiology of tracheal defects is poorly understood and new diagnoses and therapies are needed to address these relatively common yet potentially lethal defects. Human patient exome sequencing as well as murine mutant models have begun to identify a few developmental pathways that regulate tracheal development, including the Hedgehog/Gli pathway. For example, in murine models a total loss of Gli2 and Gli3 results in a complete failure of tracheal development, while some compound heterozygous Gli2;Gli3 mutants exhibit a TE cleft with tracheomalacia. In addition, our preliminary data suggests that transgenic expression of a Gli3 mutant that mimics the genetic lesion found in human Pallister-Hall syndrome patients also leads to impaired TE separation and virtually absent tracheal cartilage. The specific aims of this project are to identify Gli target genes in the developing trachea, to determine how Gli regulates TE separation and tracheal cartilage differentiation, and to model the mechanism of human tracheal defects. Preliminary RNA-seq studies of control and mutant foreguts have begun to define Gli targets during TE development. I will test the hypothesis that these candidate Gli target genes are misexpressed and/or mislocalized during TE development in Gli mutants. Our preliminary further data suggest that Wnt and BMP pathways act downstream of HH/Gli, and we will use a combination of mouse genetics and fetal foregut cultures to test the hypothesis that defective Wnt and BMP signaling is responsible for the defects in tracheal chondrogenesis. The results of these experiments will inform the basis of tracheal defects in human patients and as well as guide differentiation of tracheal iPSCs towards new therapeutic possibilities. This project will also provide valuable training in current clinical diagnosis and treatment strategies for these patients. !