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.

破坏性副肺疾病（例如肺气肿和肺纤维化）在很大程度上是不可逆的， 引起肺泡修复和再生的策略是重要的重点。此应用程序 解决指导肺泡成纤维细胞到最佳位置的机制，以生成连贯的， 机械整合的弹性和胶原纤维网络。了解信号平台如何集成和 肺泡发育过程中来自细胞外环境的状况信号对于修改如何修改如何 成纤维细胞迁移并过渡到肌纤维细胞（MF）。当他们的神经蛋白1（NRP1）耗尽时， 肺MF并未减少，但周围的Allool导管得到了增强。也是初步研究 表明胶原蛋白增强了与RAS相关的C3肉毒杆菌毒素底物-1（RAC1）激活，这是 细胞极化和迁移所必需的。假设：NRP1和Discoidin域受体2（DDR2）修改 PDGFRα介导的信号通过RAC1直接肺成纤维细胞（LF）迁移和细胞外基质 （ECM）重塑，在肺泡分离期间。这些信号通路的组成部分组装 膜脂质筏（MLR），其中整联蛋白将ECM连接到焦点粘合剂处的细胞肌动蛋白细胞骨架。 在AIM 1中，将使用PDGFRα或NRP1缺失的小鼠肺的MF来剖析信号传导 从胶原蛋白，β1-积聚蛋白和DDR2传输信息以激活Rac1的途径，从而 调节薄片的形成。这些研究将（a）研究NRP1-局部如何改变PDGFRα- 靶向蛋白激酶，衔接蛋白和鸟嘌呤核苷酸交换因子，（b）评估PDGF-A如何 与NRP1相互作用，以及（c）NRP1如何调节PDGFRα的内体运输。 AIM 2将检查缺陷 在PDGFRα，NRP1或DDR2删除小鼠的胶原蛋白纤维中，这些缺陷如何影响 MF和胶原蛋白纤维。这些研究将显示DDR2和整合素α2β1如何确定成纤维细胞的方式 响应原纤维胶原-1，包括它们的薄膜和膜1型矩阵的极化 迁移过程中金属蛋白酶（MT1-MMP）。他们还将确定胶原蛋白纤维的刚度如何 改变Rac1激活，局灶性粘合剂形成和细胞迁移。 AIM 3将研究PDGFRα和 NRP1与DDR2相互作用，并通过Rac1组装足体，其中膜型1矩阵 金属蛋白酶（MT1-MMP）靶向胶原蛋白纤维降解，以指导迁移和定位 MF。这些研究将探讨足体和Rac1如何使成纤维细胞探测和重塑胶原蛋白 沿着轴延伸到远端肺泡隔隔隔膜的纤维。在这三个目标中，胶原蛋白组成和 细胞环境的刚度将被操纵以定义它们如何影响细胞极性（Of Lamellipodia和Podosomes），Rac1激活，向更硬的底物迁移（Durotaxis）和 胶原纤维的重塑。了解MLR及其蛋白质如何构成整合和状况信号 从细胞外环境中，对于修改成纤维细胞迁移并过渡到MF至关重要。这 过程对于理解这些疾病以及如何通过肺泡进行修复至关重要 再生。因为目前可用的治疗不会阻止或逆转肺泡损失，因此 肺泡再生的策略可以大大改善肺肺气肿的临床结果，这 在美国退伍军人人口中很普遍。