Regulation of Allergen-Induced Airway Pathophysiology by Versican

项目摘要 现在人们认识到，细胞外基质(ECM)在肺(和其他组织)中提供了一个生物活性环境 器官)协调细胞功能的组织形态发生、动态平衡、伤口愈合和 疾病。我们发表的工作和初步数据使用了患有和不患有哮喘的受试者的呼吸道活检 哮喘、小鼠模型和体外细胞培养表明，ECM分子Verscan(gene=Vcan)， 积聚在下呼吸道，与炎症和呼吸道高反应性密切相关 (AHR)。我们已经发现凡西肯是由至少两个来源的过敏原合成的： 成纤维细胞和巨噬细胞，凡西康对白细胞表型、黏附和 迁移。为了更好地了解Verscan调节免疫反应的机制 变应原，我们建议使用两个新品系的条件缺陷小鼠在变态反应。这些措施包括 Vcan-/-小鼠和LysM/Vcan-/-小鼠，当他莫昔芬治疗时，Vcan-/-小鼠具有verscan的全局缺失 在髓系细胞中缺乏变态反应。Vcan-/-和LysM/Vcan-/-小鼠的肺脏明显不同 炎症反应，概括为三个主要发现：1)基质细胞(如成纤维细胞)合成 一种促进促炎细胞外基质形成的万西康；2)巨噬细胞来源的 维西康抑制呼吸道炎症，我们的初步数据表明，这是由选择性 巨噬细胞表达V3异构体；3)调节V3异构体的信号通路 WnT/β-连环蛋白/T细胞因子途径在成纤维细胞和巨噬细胞中的表达不同 调节成纤维细胞中Vcan的表达，以及我们最近定义的TLR/Trif/I型干扰素(IFN) 巨噬细胞中的途径。我们的初步和发表的观察结果强调了 了解Verscan的免疫调节特性是我们的中心假设的基础 HDM等变应原可增加成纤维细胞来源的细胞外基质的生成，形成促炎细胞外基质 这会促进呼吸道炎症和AHR，导致慢性哮喘。相反，巨噬细胞- 衍生的马鞭草形成抗炎的细胞外基质。这一假设将通过完成我们的两个 目的：目的：1.确定成纤维细胞和巨噬细胞来源的VERSICAN在呼吸道炎症和AHR中的作用 由HDM变应原引起，以及Vcan在这些细胞中表达的调控机制。目标2.定义 通西康的结构成分通过以下途径促进或抑制呼吸道炎症的机制 促炎症或抗炎ECM的形成。了解Verscan在其中的上下文设置 提供对呼吸道炎症的精细控制，AHR对于制定治疗策略至关重要 用于改善哮喘患者的预后。

Project Summary It is now recognized that the extracellular matrix (ECM) provides a bioactive environment in lungs (and other organs) that orchestrates cellular function for tissue morphogenesis, homeostasis, wound healing, and disease. Our published work and preliminary data using airway biopsies from subjects with and without asthma, mouse models, and in vitro cell cultures show that the ECM molecule, versican (gene = Vcan), accumulates in the lower airways and is strongly correlated with inflammation and airway hyperresponsiveness (AHR). We have found that versican is synthesized in response to allergens from at least two sources: fibroblasts and macrophages and that versican has a dramatic effect on leukocyte phenotype, adhesion and migration. To better understand the mechanisms whereby versican modulates the immune response to allergens, we propose to use two novel strains of mice with conditional deficiency in versican. These include Vcan-/- mice, which have a global deletion of versican when treated with tamoxifen; and LysM/Vcan-/- mice which lack versican in myeloid cells. The Vcan-/- and LysM/Vcan-/- mice have strikingly different pulmonary inflammatory responses, as summarized by three major findings: 1) stromal cells (e.g., fibroblasts) synthesize a form of versican that promotes the development of a pro-inflammatory ECM; 2) macrophage-derived versican restrains airway inflammation, which our preliminary data suggest is conferred by the selective expression of the V3 isoform of versican by macrophages; and 3) signaling pathways regulating versican expression in fibroblasts and macrophages differ, with the WNT/β-catenin/T-cell factor (TCF) pathway regulating Vcan expression in fibroblasts and, as we recently defined, the TLR/Trif/Type I interferon (IFN) pathway in macrophages. Our preliminary and published observations underscore the importance of understanding the immunomodulatory properties of versican and are the basis for our central hypothesis that allergens such as HDM increase the production of fibroblast-derived versican forming a pro-inflammatory ECM that promotes airway inflammation and AHR leading to chronic asthmatic conditions. Conversely, macrophage- derived versican forms an anti-inflammatory ECM. This hypothesis will be tested through completion of our two aims: Aim 1. Identify the role of fibroblast- vs. macrophage-derived versican in airway inflammation and AHR caused by HDM allergen and the mechanisms regulating Vcan expression in these cells. Aim 2. Define the mechanisms by which the structural components of versican promote or restrain airway inflammation through the formation of a pro- or anti-inflammatory ECM. Understanding the contextual settings in which versican provides fine control of airway inflammation and AHR is critical for the development of therapeutic strategies for improving outcomes in patients with asthma.