Guidance of pulmonary fibroblast migration during alveolar septal formation

肺泡间隔形成过程中肺成纤维细胞迁移的指导

• 批准号: 9551787
• 负责人: STEPHEN E MCGOWAN
• 金额: --
• 依托单位: IOWA CITY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9551787
• 关键词: 1-Phosphatidylinositol 3-Kinase; 3-Dimensional; Actins; Adaptor Signaling Protein; Address; Adult; Air Sacs; Alveolar; Alveolar Duct; American; Architecture; Arginine; Attenuated; BCAR1 gene; Bronchopulmonary Dysplasia; Cell Polarity; Cells; Cellular Structures; Chronic Kidney Insufficiency; Chronic Obstructive Airway Disease; Clinical; Collagen; Collagen Fiber; Cytoskeleton; Defect; Development; Diabetes Mellitus; Disease; Disease Progression; Distal; Elastic Fiber; Elastin; Environment; Extracellular Matrix; Extracellular Matrix Proteins; Fibrillar Collagen; Fibroblasts; Focal Adhesions; Gases; Generations; Goals; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Health Care Costs; Hospitalization; Impairment; Integrins; Knowledge; Learning; Link; Location; Lung; Lung diseases; MMP14 gene; Mechanics; Mediating; Membrane; Membrane Lipids; Membrane Microdomains; Metalloproteases; Movement; Mus; Myofibroblast; Natural regeneration; Neuropilin-1; Newborn Infant; Outcome; PDGFA gene; Pathogenesis; Pathologic; Phosphorylation; Physiology; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor alpha Receptor; Population; Positioning Attribute; Process; Production; Protein Kinase; Proteins; Pulmonary Emphysema; Pulmonary Fibrosis; Receptor Protein-Tyrosine Kinases; Regulation; Signal Pathway; Signal Transduction; Stroke; Symptoms; Vascular Diseases; Veterans; cell motility; discoidin domain receptor 2; extracellular; improved; mechanical force; migration; mouse model; polarized cell; rac1 GTP-Binding Protein; recruit; repaired; smoking prevalence; trafficking

Destructive parenchymal lung diseases such as emphysema and pulmonary fibrosis are largely irreversible, and strategies for eliciting alveolar repair and regeneration are an important priority. This application addresses mechanisms which guide alveolar fibroblasts to optimal locations for generation of a coherent, mechanically integrated elastic and collagen fiber network. Learning how signaling platforms integrate and condition signals from the extracellular environment during alveolar development is critical for modifying how fibroblasts migrate and transition to myofibroblasts (MF). When their neuropilin 1 (Nrp1) was depleted, pulmonary MF did not diminish but the surrounding alveolar ducts were enlarged. Preliminary studies also showed that collagen enhanced Ras-related C3 botulinum toxin substrate-1 (Rac1) activation, which is required for cell polarization and migration. Hypothesis: Nrp1 and discoidin domain receptor-2 (DDR2) modify PDGFRα-mediated signaling through Rac1 to direct lung fibroblast (LF) migration and extracellular matrix (ECM) remodeling, during alveolar septation. Components of these signaling pathways assemble in membrane lipid rafts (MLR) where integrins link the ECM to the cellular actin cytoskeleton at focal adhesions. In Aim 1, MF from the lungs of mice bearing deletions of PDGFRα or Nrp1 will be used to dissect the signaling pathways which transmit information from collagen, β1-integrins, and DDR2 to activate Rac1 and thereby regulate the formation of lamellipodia. These studies will (a) examine how Nrp1-deletion alters PDGFRα- targeted protein kinases, adapter proteins and guanine-nucleotide exchange factors, (b) evaluate how PDGF-A interacts with Nrp1, and (c) how Nrp1 regulates endosomal trafficking of PDGFRα. Aim 2 will examine defects in collagen fibers of PDGFRα, Nrp1, or DDR2-deleted mice and how these defects impact the positioning of MF and collagen fibers. These studies will show how DDR2 and integrin α2β1 determine the way fibroblasts respond to fibrillar collagen-1, including their polarization of lamellipodia and membrane type-1 matrix metalloproteinase (MT1-MMP) during migration. They will also determine how the rigidity of collagen fibers alters Rac1-activation, focal adhesion formation, and cell migration. Aim 3 will investigate how PDGFRα and Nrp1 interact with DDR2 and, via Rac1, assemble podosomes, where membrane type-1 matrix metalloprotease (MT1-MMP) targets collagen fibers for degradation to direct the migration and positioning of MF. These studies will explore how podosomes and Rac1 enable fibroblasts to probe and remodel collagen fibers along the axis extending into the distal alveolar septum. In all three aims the collagen composition and the rigidity of the cellular environment will be manipulated to define how they influence cell polarity (of lamellipodia and podosomes), Rac1 activation, migration towards stiffer substrates (durotaxis), and the remodeling of collagen fibers. Learning how MLR and their protein constituents integrate and condition signals from the extracellular environment is critical to modifying how fibroblasts migrate and transition to MF. This process is fundamental to understanding these diseases and how they may be remediated through alveolar regeneration. Because currently available treatments do not arrest or reverse alveolar loss, developing strategies for alveolar regeneration could greatly improve clinical outcomes for pulmonary emphysema, which is prevalent in the American veteran population.

破坏性肺实质疾病，如肺气肿和肺纤维化，在很大程度上是不可逆转的， 引发肺泡修复和再生的策略是该应用的一个重要优先事项。 解决引导肺泡成纤维细胞到达最佳位置以产生连贯的、 机械集成的弹性和胶原纤维网络。学习信号平台如何集成和集成。 肺泡发育过程中来自细胞外环境的条件信号对于改变肺泡发育的方式至关重要 当神经毡蛋白 1 (Nrp1) 耗尽时，成纤维细胞迁移并转变为肌成纤维细胞 (MF)。 初步研究显示，肺 MF 没有减少，但周围的肺泡管也扩大了。 表明胶原蛋白增强 Ras 相关的 C3 肉毒毒素底物-1 (Rac1) 激活，即 假设：Nrp1 和盘状蛋白结构域受体 2 (DDR2) 修饰。 PDGFRα介导的信号通过Rac1指导肺成纤维细胞（LF）迁移和细胞外基质 (ECM) 重塑，在肺泡间隔期间聚集这些信号通路的成分。 膜筏脂质 (MLR)，其中整合素将 ECM 连接到粘着斑处的细胞肌动蛋白细胞骨架。 在目标 1 中，来自 PDGFRα 或 Nrp1 缺失的小鼠肺部的 MF 将用于剖析信号传导 传递胶原蛋白、β1-整合素和 DDR2 信息以激活 Rac1 的途径 这些研究将 (a) 检查 Nrp1 缺失如何改变 PDGFRα-。 靶向蛋白激酶、接头蛋白和鸟嘌呤核苷酸交换因子，(b) 评估 PDGF-A 与 Nrp1 相互作用，以及 (c) Nrp1 如何调节 PDGFRα 的内体运输 目标 2 将检查缺陷。 PDGFRα、Nrp1 或 DDR2 缺失小鼠的胶原纤维中的缺陷以及这些缺陷如何影响胶原纤维的定位 这些研究将展示 DDR2 和整合素 α2β1 如何决定成纤维细胞的方式。 对纤维状胶原蛋白 1 做出反应，包括其片状伪足和膜 1 型基质的极化 金属蛋白酶（MT1-MMP）在迁移过程中也将决定胶原纤维的刚性。 改变 Rac1 激活、粘着斑形成和细胞迁移。 Aim 3 将研究 PDGFRα 和细胞迁移的关系。 Nrp1 与 DDR2 相互作用，并通过 Rac1 组装足小体，其中膜 1 型基质 金属蛋白酶 (MT1-MMP) 以胶原纤维为目标进行降解，以指导胶原纤维的迁移和定位 MF.这些研究将探讨足小体和 Rac1 如何使成纤维细胞探测和重塑胶原蛋白 纤维沿着轴延伸到远端肺泡隔膜中，这三个目标都是胶原蛋白成分和。 细胞环境的刚性将被操纵来定义它们如何影响细胞极性（ 板状伪足和足体）、Rac1 激活、向更硬的基质迁移（durotaxis）以及 了解 MLR 及其蛋白质成分如何整合和调节信号。 来自细胞外环境的信号对于改变成纤维细胞迁移和转变为 MF 的方式至关重要。 这个过程对于了解这些疾病以及如何通过肺泡修复这些疾病至关重要 因为目前可用的治疗方法不能阻止或逆转肺泡丢失、发展。 肺泡再生策略可以极大地改善肺气肿的临床结果， 在美国退伍军人群体中很普遍。