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: 6728168
• 负责人: Philip L. Sannes
• 金额: $ 32.85万
• 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 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6728168
• 关键词: basement membrane; binding proteins; cell cell interaction; cell growth regulation; electron microscopy; enzyme linked immunosorbent assay; extracellular matrix; fibroblast growth factor; fibroblasts; gene expression; genetically modified animals; growth factor receptors; histopathology; immunocytochemistry; laboratory rat; northern blottings; nucleic acid chemical synthesis; polymerase chain reaction; receptor binding; respiratory epithelium; sulfation; syndecan; tissue /cell culture; transfection; western blottings

DESCRIPTION (provided by applicant): The epithelium of the alveolar region of the lung is susceptible to injury, such as that induced by air-borne toxicants or oxidant stress. Interruption/delay of the replacement of these cells following injury results in faulty repair and irreversibly impaired function in the alveolus. In this proposal, we will show that there exists a critical, dynamic relationship between lung epithelial cells and fibroblasts that dictate their responsiveness to and expression of sulfated extracellular matrices (SECMs) and growth factors. This constitutes a dynamic barrier, modified by the cells themselves, that defines their selective division of labor, maximizes their common efficiency, and is reflected in specific counter-regulation of expression of these modulatory factors. The hypothesis to be addressed is: The sulfated extracellular matrix between alveolar epithelium and underlying fibroblasts selectively down-regulates generation and activity of key regulatory factors: FGF-1, -2, and -7, and their adaptor molecules (FGF-receptors, FGF-binding protein, and specific sulfated ECMs). These processes constitute critical paracrine and juxtacrine mechanisms for regulating cell numbers, cell functions, and cellular architectural arrangement under normal, hyperplastic, and disease states in the alveolus. Isolated AT2 cells will be co-cultured with fibroblasts and the intervening sulfated ECM environment modified by either exogenous addition or stimulated overproduction (enhancement) or selective inhibition/modification of gene/protein expression (reduction). To define the mechanisms that control critical epithelial cell-fibroblast interactions, cellular responses to over expression of key regulatory growth factors and inhibited translation of growth factor response adapters will be measured by DNA synthesis, relevant signaling events, and expression of selected gene/protein products. Whole animal studies using adenovector-mediated gene transfer will determine if over expression of FGF-BP or syndecan-1 improves or alters injury/repair outcomes in an in vivo model of pulmonary fibrosis. Results of these studies are expected to provide essential information needed to better understand basic cell-cell, celI-ECM relationships in homeostasis, as well as the mechanisms that steer the pathogenesis of fibrogenic change in the lung because of injury and/or disease.

描述(申请人提供)：肺泡区的上皮细胞容易受到损伤，如空气传播的毒物或氧化应激引起的损伤。损伤后这些细胞的替换中断/延迟会导致肺泡修复故障和不可逆转的功能受损。在这项研究中，我们将展示肺上皮细胞和成纤维细胞之间存在着一种关键的、动态的关系，这种关系决定了它们对硫酸盐化细胞外基质(SECM)和生长因子的反应和表达。这构成了一个动态的屏障，由细胞本身修改，定义了它们的选择性分工，最大化了它们的共同效率，并反映在对这些调节因子表达的特定反调节中。需要解决的假设是：肺泡上皮和成纤维细胞之间的硫酸盐化的细胞外基质选择性地下调关键调节因子：成纤维细胞生长因子-1、-2和-7及其适配分子(成纤维细胞生长因子受体、成纤维细胞生长因子结合蛋白和特定的硫酸盐化的ECM)的生成和活性。这些过程构成了在肺泡正常、增生和疾病状态下调节细胞数量、细胞功能和细胞结构安排的关键旁分泌和旁分泌机制。分离的AT2细胞将与成纤维细胞以及通过外源添加或刺激过量生产(增强)或选择性抑制/修饰基因/蛋白质表达(降低)来改变其间的硫酸盐化的ECM环境共同培养。为了确定控制关键的上皮细胞-成纤维细胞相互作用的机制，将通过DNA合成、相关的信号事件和选定的基因/蛋白产物的表达来衡量细胞对关键调控生长因子的过度表达和生长因子反应适配器的抑制翻译的反应。使用腺载体介导的基因转移的整体动物研究将确定在活体肺纤维化模型中，过表达的成纤维细胞生长因子-BP或Syndecan-1是否改善或改变损伤/修复结果。这些研究的结果有望提供必要的信息，以更好地理解基本的细胞-细胞、细胞外基质在稳态中的关系，以及引导因损伤和/或疾病导致的肺纤维化改变的发病机制。