REGULATION OF THE CILIATED CELL PROGRAM IN AIRWAY PROGENITORS

描述(由申请人提供)：这个项目的目标是调查呼吸系统中呼吸道上皮细胞的出现和多样化的机制。多纤毛细胞是呼吸道上皮细胞的重要组成部分，负责纤毛运输以及水和离子的运输，以优化呼吸道的清除。 除了是药物转运蛋白和生长因子受体的独特表达部位外。纤毛细胞数量、形态或功能的改变与多种疾病有关，包括哮喘、慢性阻塞性肺疾病(COPD)和纤毛疾病，如原发性睫状体运动障碍(PCD)。我们的初步研究表明，Notch是发育过程中纤毛细胞与分泌细胞命运选择的关键信号；此外，E2F4已被证明是在呼吸道上皮中形成多纤毛细胞所必需的。最近，河马-YAP途径已经成为细胞生长和分化的主要调节因子，也与纤毛发生有关。然而，Notch、E2F4和Hippo-Yap如何影响与呼吸道上皮分化相关的分子和细胞事件，以及多纤毛细胞如何在局部或对损伤做出反应时变得不同，尚不清楚。我们建议使用得失函数遗传模型和建立良好的原代呼吸道上皮细胞培养系统来解决这些问题。因此，在本项目中，我们建议：1)研究与纤毛细胞命运启动有关的细胞和分子事件，观察E2F4和Notch信号转导的作用；2)通过体内和原代培养的呼吸道上皮细胞YAP表达或磷酸化来研究Hippo-YAP在纤毛发生中的作用；3)研究调节发育中的肺的气道前体细胞纤毛细胞表型的机制，重点是Notch途径。

DESCRIPTION (provided by applicant): The goal of this project is to investigate mechanisms responsible for the emergence and diversification of airway epithelial cells in the respiratory system. Multiciliated cells are a crucial component of the airway epithelium, being responsible for ciliary transport in concert with water and ion transport for optimization of airway clearance, in addition to being unique sites for expression of drug transporters and growth factor receptors. Altered number, morphology or function of ciliated cells is associated with a variety of diseases, including asthma, chronic obstructive pulmonary disease (COPD) and ciliopathies, such as primary ciliary dyskinesia (PCD). Our preliminary studies implicate Notch as a critical signal for ciliated versus secretory cell fate selection during development; moreover, E2F4 has been shown to be essential to form multiciliated cells in the respiratory epithelium. Recently the Hippo-YAP pathway has emerged as a major regulator of cell growth and differentiation, being also implicated in ciliogenesis. Nevertheless, how Notch, E2F4 and Hippo-YAP influence the molecular and cellular events associated with differentiation of the airway epithelium and how multiciliated cells become distinct regionally or in response to injury, is unclear. We propose to address these questions using gain and loss function genetic models and a well-established primary airway epithelial culture system. Thus, in this project we propose to: 1) Investigate the cellular and molecular events associated with initiation of ciliated cell fate in the developing airways, looking at the role of E2F4 and Notch signaling ; 2) Study the role of Hippo-YAP in ciliogenesis by manipulating YAP expression or phosphorylation in vivo and in primary airway epithelial cultures; 3) Study mechanisms that modulate the ciliated cell phenotype in airway progenitors of the developing lung, focusing on the Notch pathway.