Mechanical Control of Cell Proliferation and Branching Morphogenesis in the Embryonic Lung

胚胎肺细胞增殖和分支形态发生的机械控制

• 批准号: 10323018
• 负责人: Victor D. Varner
• 金额: $ 38.02万
• 依托单位: UNIVERSITY OF TEXAS DALLAS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-15 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10323018
• 关键词: 3-Dimensional; Address; Animals; Autopsy; Biological Assay; Biophysical Process; Bronchial Tree; Cell Proliferation; Computer Models; Congenital Abnormality; Congenital diaphragmatic hernia; Cues; Defect; Development; Disease; Embryo; Embryonic Development; Engineering; Environment; Epithelial; Feedback; Fetal Lung; Fetus; Fibroblast Growth Factor; Growth; Health; Impairment; Integrins; Intervention; Knowledge; Laboratories; Liquid substance; Lung; Lung diseases; Measurement; Measures; Mechanical Stress; Mechanics; Mediating; Mesenchyme; Microfluidics; Molecular; Morphogenesis; Mus; Neonatal; Operative Surgical Procedures; Organ; Organ Culture Techniques; Pattern; Phenotype; Play; Process; Research; Respiratory physiology; Role; Signal Transduction; Stress; Structure of parenchyma of lung; System; Techniques; Testing; Time; Tissue Engineering; Tissues; Traction Force Microscopy; Work; airway epithelium; biophysical model; experience; experimental study; inhibitor; injury and repair; interdisciplinary approach; lung development; mechanical force; mechanical load; mechanical signal; new therapeutic target; novel; novel therapeutics; pressure; pulmonary hypoplasia; respiratory; treatment strategy

PROJECT SUMMARY/ABSTRACT In the embryonic lung, the bronchial tree is sculpted by a process known as branching morphogenesis. Defects in branching can cause a variety of congenital malformations, such as pulmonary hypoplasia, which compromises respiratory function due to decreased lung growth. Several of these defects are caused by changes in the mechanical environment of the fetal lung, but it remains unclear how physical cues in the tissue microenvironment direct the formation of the bronchial tree. Dynamic, quantitative studies of branching morphogenesis are needed to unravel the regulatory role of mechanical forces during lung development. We hypothesize that airway branching is driven by a mechanical feedback mechanism, in which patterns of mechanical stress regulate the patterns of epithelial proliferation that sculpt the developing airways. To test this hypothesis, we will use novel experimental platforms that allow us to control and quantify the mechanical stresses within the embryonic airway epithelium. We recently developed a novel three-dimensional (3D) traction force microscopy (TFM) assay for cultured embryonic organ explants, as well as a microfluidic system to apply controlled fluid pressures to intact embryonic mouse lungs. These techniques will be combined with dynamic studies of cell proliferation and fibroblast growth factor (FGF) signaling, as well as a novel computational model of airway branching morphogenesis, to determine how physical cues regulate the growth and remodeling of the embryonic lung. In Aim 1, we will determine how mechanical stress regulates patterns of proliferation in isolated airway epithelial explants. Then, in Aim 2, we will use whole lung explant culture to uncover how mechanical forces interact with FGFs to direct both normal and hypoplastic branching phenotypes. Achieving these aims will help identify new therapeutic targets for diseases, such as congenital diaphragmatic hernia, where airway branching morphogenesis and lung growth are severely impaired. These results will also help guide pulmonary tissue engineers in their efforts to recapitulate aspects of embryonic development in the laboratory to construct engineered lung tissue.

项目概要/摘要 在胚胎肺中，支气管树是通过称为分支形态发生的过程塑造的。缺陷 分支可引起多种先天畸形，如肺发育不全， 由于肺部生长减少而损害呼吸功能。其中一些缺陷是由 胎儿肺部的机械环境发生了变化，但仍不清楚组织中的物理信号如何变化 微环境直接指导支气管树的形成。分支的动态、定量研究 需要形态发生来揭示机械力在肺发育过程中的调节作用。我们 假设气道分支是由机械反馈机制驱动的，其中模式 机械应力调节上皮增殖模式，塑造发育中的气道。 为了检验这个假设，我们将使用新颖的实验平台来控制和量化 胚胎气道上皮内的机械应力。我们最近开发了一种新颖的三维 (3D) 培养胚胎器官外植体的牵引力显微镜 (TFM) 测定以及微流体 系统将受控流体压力施加到完整的胚胎小鼠肺部。这些技术将被结合起来 细胞增殖和成纤维细胞生长因子 (FGF) 信号传导的动态研究，以及一种新颖的 气道分支形态发生的计算模型，以确定物理线索如何调节生长 以及胚胎肺的重塑。在目标 1 中，我们将确定机械应力如何调节 离体气道上皮外植体中的增殖。然后，在目标 2 中，我们将使用全肺外植体培养来 揭示机械力如何与 FGF 相互作用以指导正常和发育不全的分支 表型。实现这些目标将有助于确定疾病的新治疗靶点，例如先天性 膈疝，气道分支形态发生和肺部生长严重受损。这些 结果还将有助于指导肺组织工程师努力重述胚胎的各个方面 在实验室中开发构建工程肺组织。