Matrix fibroblasts are required for alveolar homeostasis and regrowth

 描述（由申请人提供）：上皮-间充质细胞相互作用和控制正常肺发育的因子也是肺损伤修复和纤维化的关键因素。许多研究已经调查了上皮祖细胞在再生过程中的作用和来源。关于间充质祖细胞的起源和命运的信息有限，然而，关于损伤和修复过程中上皮间充质串扰的知识更少。这项工作的长期目标是了解成纤维细胞群体的复杂性，并确定它们在肺生成和再生中的作用。本申请的目的是鉴定成纤维细胞分化的关键调节剂，鉴定促进肺泡上皮细胞分化的成纤维细胞，并确定调节成纤维细胞分化的年龄依赖性修饰。基于强有力的初步数据，中心假设是GATA 6是基质基因签名的关键调节因子，并且基质成纤维细胞的损失干扰上皮-间充质相互作用。这项研究的基本原理是，了解成纤维细胞亚群的调节及其在上皮-间充质细胞相互作用中的独特作用，将为有关肺部疾病和再生的基本问题提供新的答案。将以三个特定目的测试该假设：1）确定GATA 6在肺泡再生期间调节基质基因签名和成纤维细胞分化的功能2）确定基质成纤维细胞在肺泡上皮细胞分化中的作用3）鉴定调节老化肺中成纤维细胞分化的表观遗传修饰。在第一个目标中，GATA 6功能获得和丧失研究 将用于建立肺泡再生和间质成纤维细胞分化可塑性之间的功能联系。在第二个目标中，肺泡球培养物将用于询问Gata 6突变间质成纤维细胞和野生型肺泡上皮细胞之间的上皮-间充质串扰。在第三个目标中，将通过ChIP-PCR分析评估EZH 2对表观遗传Gata 6启动子的修饰。使用EZH 2抑制剂的体内和体外研究将确定EZH 2在抑制Gata 6和基质成纤维细胞特征基因中的作用。这些研究将更好地了解肌和基质成纤维细胞的分化以及成纤维细胞多样性对再血管化期间上皮-间充质串扰的影响。这一贡献将是重要的，因为它将推进有关肺泡再生所涉及的基因和途径的知识，对随着年龄增长而减少再生的原因提供新的见解，并为克服目前人类肺部再生限制的新疗法提供基础。我们对肺成纤维细胞在 肺损伤和再生远远落后于我们对上皮细胞作用的理解。新 关于间质性肺成纤维细胞的信息对于确定正常肺修复和病理性肺病发展的机制是非常宝贵的。

 DESCRIPTION (provided by applicant): Epithelial-mesenchymal cell interaction and factors that control normal lung development are also key players in lung injury repair and fibrosis. Many studies have investigated the role and source of epithelial progenitors during regeneration. There is limited information on the origin and fate of mesenchymal progenitor cells, however, even less knowledge about epithelial mesenchymal crosstalk during injury and repair. The long-term goal of this work is to understand the complexity of fibroblast populations and to identify their role in lung generation and regeneration. The objective in this application i to identify key regulators of fibroblast differentiation, identify fibroblasts that promote alveola epithelial cell differentiation and to determine age dependent modifications that regulate differentiation of fibroblasts. Based on strong preliminary data, the central hypothesis is that GATA6 is a key regulator of the matrix gene signature and that loss of matrix fibroblasts disturbs epithelial-mesenchymal interactions. The rationale for the proposed research is that understanding the regulation of fibroblast subpopulations, and their distinct role in epithelial-mesenchymal cell interactions, will provide new answers for fundamental questions regarding lung disease and regeneration. This hypothesis will be tested with three specific aims: 1) determine the function of GATA6 in regulating the matrix gene signature and fibroblast differentiation during alveolar regeneration 2) determine the role of the matrix fibroblast in alveolar epithelial cell differentiation 3) identify the epigenetic modifications that regulate fibroblast differentiation in aged lungs. In the first aim, GATA6 gain and loss of function studies will be used to establish a functional link between alveolar regeneration and differentiation plasticity of interstitial fibroblasts. In the second aim, alveolosphere cultures will be used to interrogate the epithelial-mesenchymal crosstalk between Gata6 mutant interstitial fibroblasts and wild type alveolar epithelial cells. In the third aim, epigenetic Gata6 promoter modifications by EZH2 will be assessed by ChIP-PCR analysis. In vivo and in vitro studies using EZH2 inhibitors will determine a role of EZH2 in suppressing Gata6 and matrix fibroblast signature genes. These studies will provide a better understanding of myo and matrix fibroblast differentiation and the impact of fibroblast diversity on epithelial-mesenchymal crosstalk during realveolarization. This contribution will be significant because it will advance the knowledge about genes and pathways involved in alveolar regeneration, give new insights into the cause of decreased regrowth with age and provide the basis for new therapies to overcome current limitations of regeneration in the human lung. Our understanding of the role of lung fibroblasts in lung injury and regeneration lags far behind our understanding of the role of epithelial cells. New information about interstitial lung fibroblasts will be invaluable for defining mechanisms of normal lung repair and pathologic lung disease development.