The Fetal Lung Mesothelial Differentiation Program

胎儿肺间皮分化计划

基本信息

批准号：
8712548
负责人：
Xingbin Ai
金额：
$ 61.15万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-05 至 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8712548
关键词：
Address Adult Alleles Allergens Appearance Area Asthma Attenuated Back Binding Biology Body cavities Cell Line Cell Lineage Cells Data Development Embryo Epithelium Erinaceidae Event Fetal Lung Fibrosis Flow Cytometry Foundations Future Gene Expression Generations Genes Goals Grant Green Fluorescent Proteins Growth Harvest Heart Immigration Individual Inflammation Inflammatory Investigation Kinetics Knock-in Mouse Label Lead Life Liver Lung Mediating Mesenchymal Mesenchyme Mesothelial Cell Mesothelium Messenger RNA Modeling Mus Nephroblastoma Organ Ovalbumin Pathway interactions Pattern Phenotype Play Ploidies Pneumonectomy Primates Process Reporter Rest Role Rosa Signal Transduction Smooth Muscle Myocytes Squamous Cell Tamoxifen Testing Time Tissues Total Lung Capacity Work body cavity fetal injured lung development lung injury lung repair migration monolayer mouse development mutant novel progenitor programs promoter public health relevance recombinase repaired research study selective expression smoothened signaling pathway transcription factor

项目摘要

DESCRIPTION (provided by applicant): To what extent mesothelial-derived cells contribute to lung development and post-natal repair is an open and basic question for the field. The objectives of this grant are to address this fundamental issue and to assess the key role of the Wilm's tumor 1 transcription factor (WT1) in these events. Using mouse lines that carry WT1 alleles with a knock-in Cre recombinase and GFP genes, we generated preliminary data leading to 3 hypotheses that will be examined: 1) the fetal mesothelium contains progenitors for differentiated mesenchymal lung cells 2) WT1 controls the expression of key genes, such as hedgehog (Hh) pathway constituents that control mesothelial migration into the fetal lung, and 3) mesothelium-derived cells contribute to post-natal lung repair and re-growth. To summarize, we found that WT1 is selectively expressed in the lung mesothelium from E11.5 to E16 and is undetectable in the adult. We identified a similar temporal pattern of WT1 expression in the primate lung, suggesting a conserved mesothelial WT1 program across mammalian species. Lineage tracing showed that mesothelium-derived cells give rise to a substantial number of bronchial smooth muscle cells (BSM), along with other parenchymal lung cells whose identities will be established (Aim 1). We observed that WT1 expression coincides with mesothelial cell entry into the underlying lung and active Hh signaling. Mechanistically, we found that WT1 binds to the promoters of multiple Hh pathway genes in mesothelial cells, and that selective loss of mesothelial Hh signaling markedly attenuates entry into the underlying lung in association with diminished expression of EMT genes. These data point to a key role for WT1 in the fetal mesothelium, controlling pathways such as Hh signaling that are involved in migration and EMT, which will be further explored (Aim 2). Interestingly, preliminary data indicate that WT1 is reactivated during lung re-growth post-pneumonectomy whereas WT1 is not re-activated in inflammatory lung injuries, such as asthma and fibrosis. These findings suggest 2 models for how the mesothelium may contribute to lung remodeling in post-natal life. In model 1, the fetal WT1-regulated mesothelial program is re-activated. In model 2, parenchymal cells that arise from the fetal mesothelium in development contribute to repair. To what degree these models are involved in lung re- growth and remodeling in post-natal life will be further examined (Aim 3). We expect that completion of these studies will establish a firm foundation for future work in this new area of lung biology.

描述（由申请人提供）：间皮细胞衍生的细胞在多大程度上有助于肺部发育和产后修复，这是该领域的开放和基本问题。该赠款的目标是解决这个基本问题，并评估Wilm肿瘤1转录因子（WT1）在这些事件中的关键作用。使用带有WT1等位基因的小鼠系带有CRE重组酶和GFP基因，我们产生了将检查的3个假设的初步数据：1）胎儿间皮子包含分化的间质肺肺细胞2）WT1的胎儿含量，例如，wt1 wt1控制了基因的表达。胎儿肺和3）间皮细胞有助于产后肺修复和重长。总而言之，我们发现WT1在肺间皮中有选择地表达从E11.5到E16，并且在成年人中无法检测到。我们确定了灵长类动物肺中WT1表达的类似时间模式，这表明在哺乳动物物种上有保守的间皮WT1程序。谱系追踪表明，间皮细胞会产生大量支气管平滑肌细胞（BSM），以及其他将建立同一性的实质肺细胞（AIM 1）。我们观察到WT1表达与间皮细胞进入下层肺和活性HH信号传导一致。从机械上讲，我们发现WT1与间皮细胞中多个HH途径基因的启动子结合，并且选择性丧失间皮HH信号的选择性损失显着减弱，与EMT基因表达降低有关。这些数据表明，WT1在胎儿间皮中的关键作用，控制了迁移和EMT涉及的HH信号等途径，将进一步探索（AIM 2）。有趣的是，初步数据表明，在肺部再生切除术后肺部重生期间，WT1已重新激活，而WT1在炎性肺损伤（例如哮喘和纤维化）中未重新激活。这些发现提出了2个模型，说明间皮可能如何促进产后生命中的肺部重塑。在模型1中，重新激活了胎儿WT1调节的间皮计划。在模型2中，由发育中的胎儿间皮产生的实质细胞有助于修复。这些模型在多大程度上涉及到产后生命中的肺部恢复和重塑（AIM 3）。我们预计这些研究的完成将为将来的工作建立坚定的基础肺部生物学的新领域。