Regulation of Allergen-Induced Airway Pathophysiology by Versican

项目摘要 现在认识到，细胞外基质（ECM）在肺（和其他组织）中提供生物活性环境。 器官），其协调用于组织形态发生、体内平衡、伤口愈合的细胞功能，以及 疾病我们发表的工作和初步数据使用了来自有和没有 哮喘、小鼠模型和体外细胞培养显示，ECM分子，多功能蛋白聚糖（基因= Vcan）， 在下呼吸道积聚，并与炎症和气道高反应性密切相关 （AHR）。我们已经发现多功能蛋白聚糖是响应于来自至少两种来源的过敏原而合成的： 多功能蛋白聚糖对白细胞表型、粘附 迁移为了更好地理解多功能蛋白聚糖调节免疫反应的机制， 过敏原，我们建议使用两种新的小鼠品系与条件缺陷的多功能蛋白聚糖。这些包括 Vcan-/-小鼠，其在用他莫昔芬处理时具有多功能蛋白聚糖的整体缺失;和LysM/Vcan-/-小鼠 缺乏多功能蛋白聚糖Vcan-/-和LysM/Vcan-/-小鼠具有显著不同的肺功能。 炎性反应，总结为三个主要发现：1）基质细胞（例如，成纤维细胞）合成 一种多功能蛋白聚糖，促进促炎性ECM的发展; 2）巨噬细胞源性 多能蛋白聚糖抑制气道炎症，我们的初步数据表明，这是由选择性的 多功能蛋白聚糖V3亚型在巨噬细胞中的表达;以及3）调节多功能蛋白聚糖的信号传导途径 成纤维细胞和巨噬细胞中的表达不同，WNT/β-连环蛋白/T细胞因子（TCF）途径 调节成纤维细胞中Vcan的表达，正如我们最近定义的，TLR/Trif/I型干扰素（IFN） 巨噬细胞中的通路。我们的初步和发表的意见强调了以下方面的重要性： 了解多功能蛋白聚糖的免疫调节特性，是我们中心假设的基础， 过敏原如HDM增加成纤维细胞衍生的多功能蛋白聚糖的产生，形成促炎性ECM 其促进气道炎症和AHR，导致慢性哮喘病症。相反，巨噬细胞- 衍生的多功能蛋白聚糖形成抗炎ECM。这一假设将通过完成我们的两个测试。 目标：目标1。鉴定成纤维细胞与巨噬细胞来源的多功能蛋白聚糖在气道炎症和AHR中的作用 引起的HDM过敏原和调节Vcan在这些细胞中的表达的机制。目标2.定义 多功能蛋白聚糖的结构成分通过以下机制促进或抑制气道炎症： 促炎或抗炎ECM的形成。了解versican的上下文设置 提供了对气道炎症的精细控制，并且AHR对于治疗策略的开发至关重要 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.