FGF18 regulation of postnatal lung development

FGF18 调节产后肺部发育

基本信息

批准号：
10444913
负责人：
David M Ornitz
金额：
$ 62.51万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-15 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10444913
关键词：
Adult Air Alveolar Alveolar wall Alveolus Apoptotic Area Atlases Blood Vessels Blood capillaries Blood gas Bronchopulmonary Dysplasia Cell Differentiation process Cell Maturation Cell Nucleus Cell Separation Cells Communities Complication Coupled Defect Development Disease Elastin Embryo Ensure Epithelial Epithelial Cells Extracellular Matrix FGFR3 gene FGFR4 gene Fibroblast Growth Factor Fibroblasts Gases Gene Expression Gene Silencing Genetic Health Human Impairment Knowledge Ligands Lung Mesenchymal Mesenchymal Stem Cells Mesenchyme Molecular Mus Myofibroblast Neonatal Organ Pharmacological Treatment Phase Population Premature Birth Premature Infant Process Production Proliferating RNA Regulation Research Resources Rodent Saccule structure Signal Transduction Signaling Molecule Source Structure Supportive care Surface Thinness Vitamin A base cell type chronic respiratory disease deep sequencing experimental study fibroblast growth factor 18 improved outcome infant outcome lung development lung regeneration novel postnatal progenitor programs response therapy development tool transcriptome sequencing

项目摘要

Title: FGF18 regulation of postnatal lung development Summary: Alveologenesis is the final stage of lung development where the surface area of the lung is increased by subdividing alveolar saccules through the formation of secondary septae (septal ridges), followed by thinning of the septal walls to generate an efficient air/blood gas exchange organ. Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth in which alveologenesis is impaired. BPD often results in chronic respiratory disease. However, besides Vitamin A and supportive care, no therapies exist to promote lung alveolar and vascular development to improve the outcomes of infants with BPD. Alveologenesis can be divided into two phases in humans and rodents. During the first phase, alveolar myofibroblasts (AMFs) and other mesenchymal and epithelial cells regulate the formation of secondary septae. During the second phase, the septal walls undergo a maturation process that involves thinning, through loss of mesenchymal cells and remodeling of the microvasculature, to a single layer capillary network juxtaposed with alveolar type 1 (AT1) cells. The mature alveolar wall ensures efficient air/blood gas exchange in the adult lung. An in-depth understanding the mechanisms that regulate alveolar septation and septal wall maturation will be required to develop therapies for premature infants with BPD and for developing potential therapies for adult lung regeneration. However, there are specific knowledge gaps about the identity of mesenchymal progenitors that give rise to AMFs, the functions of AMFs and other mesenchymal cell types, and the mechanisms that terminate and clear AMFs from the lung at the completion of secondary septation. Fibroblast Growth Factor 18 (Fgf18) is expressed at high levels in AMFs and AT1 cells during alveologenesis. We show that conditional inactivation of Fgf18 in the neonatal lung results in impaired alveologenesis. Through lineage tracing of Fgf18-expressing cells, we find that the AMFs are cleared from the lung after the first phase of alveologenesis, coinciding with alveolar wall thinning, but that AT1 cells are retained. In this proposal, we use a combination of unique genetic tools for lineage tracing and gene inactivation, cell sorting coupled with RNA deep sequencing, and single cell and single nuclei RNA sequencing, to identify the relative contribution of mesenchymal and epithelial FGF18 to the first and second phases of alveologenesis, the cellular response(s) to FGF18 during alveologenesis, the progenitors that give rise to fibroblasts sub-types in alveolar septae, and the mechanisms that specifically clear AMFs from the lung. The proposed experiments will also generate an atlas of gene expression for septal mesenchymal cell types present during alveologenesis that will serve as a resource for the research community.

标题：FGF18 调节产后肺部发育概括：肺泡发生是肺发育的最后阶段，其中肺表面积增加通过形成次级隔膜（隔膜脊）来细分肺泡球囊，然后使肺泡球囊变薄隔膜壁产生有效的空气/血液气体交换器官。支气管肺发育不良（BPD）是一种早产的常见并发症，其中肺泡生成受损。 BPD 常常导致慢性呼吸道疾病。然而，除了维生素 A 和支持治疗外，没有任何疗法可以促进肺泡和血管发育，以改善 BPD 婴儿的预后。人类和啮齿动物的肺泡发生可分为两个阶段。在第一阶段，肺泡肌成纤维细胞（AMF）和其他间充质和上皮细胞调节次级隔膜的形成。在第二阶段，隔膜壁经历一个成熟过程，其中包括通过失去间充质细胞和微脉管系统的重塑，形成单层毛细血管网络肺泡 1 型 (AT1) 细胞。成熟的肺泡壁确保成人肺中有效的空气/血液交换。深入了解调节肺泡间隔和间隔壁成熟的机制将是需要为患有 BPD 的早产儿开发治疗方法以及为成人开发潜在的治疗方法肺再生。然而，关于间充质祖细胞的身份存在特定的知识差距产生 AMF、AMF 和其他间充质细胞类型的功能以及产生 AMF 的机制在二次分隔完成时终止并清除肺部的 AMF。成纤维细胞生长因子 18 (Fgf18) 在肺泡形成过程中在 AMF 和 AT1 细胞中高水平表达。我们发现新生儿肺中 Fgf18 的条件性失活会导致肺泡生成受损。通过对表达 Fgf18 的细胞进行谱系追踪，我们发现 AMF 在第一阶段后从肺中被清除。肺泡发生，与肺泡壁变薄同时发生，但 AT1 细胞被保留。在本提案中，我们结合使用独特的遗传工具进行谱系追踪和基因失活、细胞分选与 RNA 深度测序以及单细胞和单核 RNA 测序相结合，以鉴定间充质和上皮 FGF18 对肺泡发生第一和第二阶段的相对贡献，肺泡形成过程中对 FGF18 的细胞反应，肺泡形成过程中产生成纤维细胞亚型的祖细胞肺泡隔膜，以及从肺部特异性清除 AMF 的机制。拟议的实验将还生成肺泡发生过程中存在的间隔间充质细胞类型的基因表达图谱将作为研究界的资源。