Alveolar Basement Membrane/Cell Interactions in the Lung

肺中肺泡基底膜/细胞的相互作用

• 批准号: 7625297
• 负责人: Philip L. Sannes
• 金额: $ 37.13万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7625297
• 关键词: AGTR2 gene; Address; Adenovirus Vector; Affect; Alveolar; Alveolar Cell; Alveolus; Animal Model; Automobile Driving; Basal lamina; Basement membrane; Binding; Biological Models; Bleomycin; Cell Communication; Cell Count; Cell Death; Cell Differentiation process; Cell Nucleus; Cell physiology; Cells; Coculture Techniques; Complex; Condition; Cytokinesis; DNA Sequence; DNA biosynthesis; DNA chemical synthesis; Daughter; Disease; Enhancers; Environment; Epithelial; Epithelial Cells; Epithelium; Equilibrium; Event; Extracellular Matrix; Family; Fibroblasts; Fibrosis; Figs - dietary; Foxes; Gene Expression; Gene Expression Regulation; Gene Proteins; Genetic; Growth Factor; Growth Factor Interaction; Heparan Sulfate Proteoglycan; Heparin; Homeostasis; Human; In Vitro; Injury; Inorganic Sulfates; Left; Lung; Lung diseases; Maintenance; Metalloproteases; Methods; Modeling; Mus; Nuclear; Pathogenesis; Pathway interactions; Phenotype; Process; Production; Protein Overexpression; Proteins; Pulmonary Fibrosis; Range; Rattus; Regulation; Relative (related person); Resolution; Rodent; Signal Pathway; Signal Transduction; Signaling Molecule; Stimulus; Type II Epithelial Receptor Cell; Unspecified or Sulfate Ion Sulfates; WNT Signaling Pathway; Work; autocrine; cell type; cytokine; daughter cell; forkhead protein; genetically modified cells; in vivo; in vivo Model; inhibitor/antagonist; knockout gene; loss of function; novel; paracrine; repaired; response; sulfation; transcription factor

The pathogenesis of fibrotic lung disease involves damage or injury to type 2 cells (AT2) in the alveolus which compromises their ability to differentiate properly into type 1 (AT1) cells, leading to faulty epithelial repair, irreversible damage, loss of function, and fibrosis. Mechanisms that normally control the process of differentiation of AT2 cells into AT1s are not understood, so potential regulatory molecules or pathways that may be affected by these pathogenic stimuli have not been elucidated. We propose that the key to alveolar cell differentiation is the relative sulfation of the extracellular matrix (ECM) microenvironment underlying alveolar cell types. This in turn controls activation of the wingless (Wnt) signaling pathways and the forkhead (Fox) family of transcription factors. Activation of these signaling molecules regulates cell differentiation and phenotype in the alveolus. In this proposal, we will show that following proliferative events associated with reepithelialization in the alveolus, there is a critical, dynamic balance between alveolar epithelial cells and their ECM microenvironment. This is significantly modulated by both fixed and soluble sulfated ECMs, whose downstream effect is to specifically modulate WNT signaling and enhance FOXA1 expression. These factors and pathways then regulate specific events that both maintain AT2 cell number and phenotype, and effectively drive cell differentiation to AT1s. The hypothesis to be addressed is: Following DNA synthesis and cytokinesis, exposure of the daughter AT2 cell to high levels of sulfated ECMs triggers sequential expression of forkhead transcription factors (Foxa2 > Foxa1 > Foxp2) and increases Wnt7a expression and signaling which together drive differentiation of AT1 cells. To address this hypothesis, we will culture isolated human or rodent AT2 cells, alone as well as in co-culture with lung fibroblasts, central regulators of the AT2 cell microenvironment. AT2 cells (human or rat), or cells from genetically modified mice will be treated with specific enhancers or inhibitors of Wnt production, FOX gene and protein regulation, and SECM composition. These results will be compared with examination of targeted molecules by protein and/or gene expression methods in a whole animal model of pulmonary fibrosis. Results of these studies are expected to provide essential information needed to better understand basic cell-cell and cell-ECM relationships in alveolar epithelial homeostasis as well as the mechanisms that steer the pathogenesis of fibrogenic change in the lung as a consequence of alveolar injury and/or disease.

纤维化肺病的发病机制涉及对肺泡中的2型细胞（AT 2）的损伤或伤害， 损害了它们正确分化为1型（AT 1）细胞的能力，导致上皮修复缺陷， 不可逆损伤、功能丧失和纤维化。通常控制这一过程的机制 AT 2细胞向AT 1细胞的分化尚不清楚，因此潜在的调节分子或途径， 可能受到这些致病刺激的影响尚未阐明。我们认为肺泡细胞的关键 分化是肺泡细胞外基质（ECM）微环境的相对硫酸化， 细胞类型。这反过来又控制无翅（Wnt）信号通路和叉头（Fox）信号通路的激活。 转录因子家族。这些信号分子的激活调节细胞分化和 肺泡中的表型。在这个建议中，我们将表明，以下与上皮再生相关的增殖事件 在肺泡中，在肺泡上皮细胞和它们的细胞之间存在关键的动态平衡。 ECM微环境。这受到固定和可溶性硫酸化ECM的显著调节， 下游效应是特异性调节WNT信号传导并增强FOXA 1表达。这些因素 和途径，然后调节特定的事件，既保持AT 2细胞的数量和表型，并有效地 驱动细胞分化为AT 1。要解决的假设是：在DNA合成和 胞质分裂，子AT 2细胞暴露于高水平的硫酸化ECM触发了顺序的 表达叉头转录因子（Foxa 2> Foxa 1> Foxp 2）并增加Wnt 7a表达 和信号传导共同驱动AT 1细胞的分化。为了解决这个假设，我们将培养 分离的人或啮齿动物AT 2细胞，单独以及与肺成纤维细胞共培养，肺成纤维细胞是肺成纤维细胞的中枢调节因子， AT 2细胞微环境。将处理AT 2细胞（人或大鼠）或来自遗传修饰小鼠的细胞 具有Wnt产生、FOX基因和蛋白质调节以及SECM的特异性增强剂或抑制剂 混合物.这些结果将与通过蛋白质和/或基因检测靶分子进行比较 在肺纤维化的整体动物模型中的表达方法。这些研究的结果预计将 为更好地了解肺泡上皮细胞中基本的细胞-细胞和细胞-ECM关系提供了必要的信息。 上皮内稳态以及引导肺纤维化变化发病机制的机制 由于肺泡损伤和/或疾病。