Integrated Molecular and Cellular Drivers of Alveologenesis

肺泡发生的综合分子和细胞驱动因素

基本信息

批准号：
10637764
负责人：
Jennifer MalcolmSrygley Sucre
金额：
$ 72.89万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-20 至 2028-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10637764
关键词：
Ablation Agonist Alveolar Alveolus Architecture Blood capillaries Bronchopulmonary Dysplasia Capillary Endothelial Cell Cell Differentiation process Cell Nucleus Cell Proliferation Cells Chromatin Collagen Data Development Distal Endothelial Cells Endotoxins Epithelial Cells Epithelium Extracellular Matrix Extracellular Matrix Proteins Fluorescent in Situ Hybridization Four-dimensional Generations Genetic Transcription Goals Growth Health Human Hyperoxia Image Immunofluorescence Immunologic Impairment Inflammation Injury Knowledge Laminin Libraries Light Lung Mesenchymal Microscopy Modeling Molecular Molecular Target Myofibroblast Pathway interactions Pattern Phenotype Pregnancy Premature Birth Premature Infant Process Production Proliferating Publishing Regulation Reporter Resolution Role Sampling Signal Pathway Signal Transduction Slice Structure Testing Therapeutic Time Transgenic Organisms Visualization WNT Signaling Pathway alveolar epithelium antagonist capillary bed cell motility delivery complications experimental study extracellular high risk in vivo inhibitor innovation lung development lung injury multiple omics neonatal exposure neonatal injury neonatal lung injury neonatal mice neonate new growth novel strategies overexpression postnatal pulmonary function real-time images recruit response restoration scaffold second harmonic spatial relationship spatiotemporal temporal measurement transcriptome sequencing transcriptomics

项目摘要

PROJECT SUMMARY Neonates born during the saccular stage of lung development (23-32 wks gestation) are at highest risk for bronchopulmonary dysplasia (BPD), a leading preterm birth complication. The mechanisms underlying this vulnerability are poorly defined, a knowledge gap we consider foundational to the lack of curative BPD therapies. To understand the irreversibility of arrested alveologenesis in BPD, we require a refined, mechanistic understanding of the normal saccular to alveolar transition. Our preliminary data from 4- dimensional live imaging and single-cell transcriptomics support a new model of alveologenesis in which myofibroblast ring structures support the extrusion of AT2s (alveolar type 2 cells) followed by their differentiation into AT1s (alveolar type 1 cells). According to our model, mature AT1s produce ECM proteins and other factors that recruit specialized endothelial cells to become the alveolar capillary bed. Sequential, spatiotemporally restricted signaling pathways, including Wnt and BMP, coordinate cell movement, proliferation, and architecture. We have developed a neonatal injury model with a phenotype of impaired alveologenesis that is relevant to human BPD by exposing neonatal mice to hyperoxia and inflammation during the saccular stage. Our preliminary data from this model associate overexpression of Wnt5A/Wnt11 with impaired alveologenesis. Post-injury deficits include decreased BMP production and activity in alveolar epithelial cells and impaired AT2 to AT1 cell differentiation and decreased expression of extracellular matrix (ECM) components by AT1 cells. Based on preliminary and published data, we hypothesize that alveologenesis involves formation of a ring of myofibroblasts that express Wnt5a and Wnt 11 to drive AT2 proliferation and promote extrusion through the ring. Subsequent epithelial BMP production down-regulates Wnt, promoting AT2 to AT1 differentiation and generation of an extracellular scaffold for capillary assembly. Injury dysregulates Wnt and Bmp signaling, perturbing the precise spatiotemporal patterning during this critical timeframe and resulting in arrested alveologenesis and long-term functional deficits. We will test this hypothesis in the following specific aims: 1) Define the role of myofibroblast Wnt expression in regulating AT2 proliferation and alveolar development; 2) Characterize mechanisms by which BMP signaling regulates AT2-to-AT1 cell differentiation; 3) Determine the mechanisms whereby nascent AT1 cells generate a scaffold for the developing alveolus. Successful completion of this proposal is anticipated to transform our understanding of alveologenesis, identifying new molecular targets to promote post-injury alveolar restoration and the optimal time windows for deployment of such newly directed therapies.

项目摘要在肺部发育的寒冷阶段出生的新生儿（妊娠23-32周）的风险最高支气管肺发育不良（BPD），一种领先的早产并发症。这是基础的机制脆弱性的定义很差，我们认为缺乏治疗性BPD的知识差距疗法。要了解BPD中被捕的肺单术的不可逆性，我们需要一个精致的，对正常囊到牙槽跃迁的机械理解。我们从4-的初步数据尺寸实时成像和单细胞转录组学支持一种新的肺单元模型，其中肌纤维细胞环结构支持AT2S（牙槽2型细胞）的挤出分化为AT1（牙槽1型细胞）。根据我们的模型，成熟的AT1产生ECM蛋白以及募集专门的内皮细胞成为肺泡毛细血管床的其他因素。顺序，时空限制的信号通路，包括Wnt和BMP，坐标细胞运动，扩散和建筑。我们已经开发了一种新生儿损伤模型，具有受损的表型通过将新生小鼠暴露于高氧和炎症中，与人BPD相关的肺泡术寒冷阶段。我们来自Wnt5a/Wnt11的该模型关联过表达的我们的初步数据肺单元受损。伤害后缺陷包括降低BMP的产生和肺泡活性上皮细胞并损害AT2至AT1细胞分化和细胞外基质的表达降低（ECM）AT1细胞组件。根据初步和已发布的数据，我们假设肺单元涉及形成表达Wnt5a和Wnt 11的肌纤维细胞环以驱动AT2 扩散并通过环促进挤出。随后的上皮BMP生产下调 Wnt，将AT2促进至AT1分化和毛细管组件的细胞外支架的产生。伤害失调WNT和BMP信号传导，在此关键时期扰动精确的时空图案时间范围并导致肺单术和长期功能缺陷。我们将测试这个在以下特定目的中的假设：1）定义肌成纤维细胞Wnt在调节中的作用 AT2增殖和肺泡发育； 2）表征BMP信号传导的机制调节AT2至AT1细胞分化； 3）确定新生AT1细胞的机制为发育中的肺泡产生脚手架。预计该提议的成功完成将改变我们对肺泡术的理解，识别新的分子靶标以促进伤害后肺泡修复和部署这种新定向疗法的最佳时间窗口。