Role of Extracellular Remodeling in Epthelial Defense

项目4：细胞外重构在上皮防御中的作用 感染性物质、过敏原和其他有害物质通过暴露的粘膜表面进入，如 呼吸道、胃肠道和泌尿生殖道。对这些病原体的反应 炎症细胞和免疫细胞被招募，并在趋化作用下穿过上皮屏障 渐变。为了保持其作为感染屏障的功能，必须有足够数量的炎症细胞 穿过管腔空间。此外，如果粘膜上皮受损，对 感染消失了。因此，必须尽快恢复上皮屏障，以最大限度地减少 传染病病原体进入的机会。基质金属蛋白酶(MMPs)在肺组织中表达上调 损伤、修复和炎症。蛋白水解力改变的转基因小鼠模型独一无二 阐明细胞外蛋白分解的重要细胞和遗传途径的机会 参与这些上皮细胞的防御机制。这项提案的总体目标是确定 影响上皮细胞防御(炎症细胞募集，上皮修复)的通路由这些调控 酵素。我们将讨论基质金属蛋白酶相互作用的特征和功能意义 体内和体外方法：过敏性炎症和感染以及主要的上皮损伤。作为一名 粘膜组织，我们将主要集中在肺，但根据需要，也会询问其他粘膜 纸巾。我们建议确定这些基因在调节炎症细胞行为中的作用。 跨内皮和跨上皮出口。我们假设，调节失调的呼吸道基质金属蛋白酶活性可以改变 炎症细胞通过改变细胞外重塑影响其合成或释放的行为 化学诱导剂和/或化学吸引作用的拮抗剂进入空气空间，从而产生化学诱导剂 将细胞从实质空间吸引到空气空间所需的梯度没有形成或 维护好了。此外，我们假设这些酶调节上皮修复的过程。 作为炎症的结果是必要的。我们将在体内使用微生物或它们的 感染模型中的产品(项目2)或具有遗传基因的小鼠的过敏性致敏 改变基质金属蛋白酶的表达或活性，或用基质金属蛋白酶抑制剂治疗小鼠。我们将对细胞进行评估 在空地上招募。我们将使用光学成像(核心C)来研究与微生物的反应 或其产品在体内、体外无菌炎症、感染或过敏性致敏模型 在上皮细胞培养模型中。我们将使用具有基因修饰的小鼠来表达这些 基因，集中在MMP2、MMP9和MMP13。我们将使用突变小鼠、特定的抑制剂和正常的 以及培养中的转基因上皮细胞，以与项目1、2、3和核心B和 C、探讨这些基因中的一种在上皮伤口愈合中的作用。这一点的直接影响 研究工作是将其应用于使用滴注的化学诱导剂和其他修饰分子 上皮防御，并将提供原理证明，这些关键的基质金属蛋白酶底物潜在地 在干预上皮防御机制方面有效。只有透彻地了解这些行为 而这些酶及其主要底物的作用将有助于减轻对感染的防御，因此 将足够数量的炎性细胞重新招募到上皮屏障和 上皮细胞自我修复的能力可以加速。

Project 4: Role of Extracellular Remodeling in Epithelial Defense Infectious agents, allergens and other noxious agents enter through exposed mucosal surfaces, such as the respiratory, gastrointestinal and genitourinary tracts. In response to these patholological agents inflammatory and immune cells are recruited and cross the epithelial barrier in response to a chemotactic gradient. To maintain their function as a barrier to infection, an adequate number of inflammatory cells must cross into the luminal spaces. In addition, if the mucosal epithelium is compromised, the defense against infection is lost. The epithelial barrier must therefore be restored as quickly as possible, to minimize the opportunity for entry of infectious agents. Matrix metalloproteinases (MMPs) are upregulated during lung injury, repair and inflammation. Transgenic mouse models with altered proteolytic potential present unique opportunities to elucidate important cellular and genetic pathways by which extracellular proteolysis participates in these epithelial defense mechanisms. The overall goal of this proposal is to identify the pathways impacting epithelial defense (inflammatory cell recruitment, epithelial repair) regulated by by these enzymes. We will address the characteristics and functional significance of MMP interactions by combined in vivo and in vitro approaches: allergic inflammation and infection and the attending epithelial damage. As a mucosal tissue, we will primarily focus on the lung, but, as needed, will also will interrogate other mucosal tissues. We propose to determine the role of these genes in regulating inflammatory cell behavior during transendothelial and transepithelial egress. We hypothesize that dysregulated airway MMP activity modifies the behavior of inflammatory cells by altering extracellular remodeling that impacts on synthesis or release of chemoattractants and/or antagonists of chemoattractant action, into the airspaces, and thus chemoattractant gradients needed to attract the cells out of the parenchymal space into the airspaces are not formed or maintained. Moreover we hypothesize that these enzymes regulate the processes of epithelial repair necessary as a consequence of inflammation. We will study this in vivo using micro-organisms or their products in models of infection (with Project 2) or allergic sensitization in mice that have genetic modifications in MMP expression or activity, or treat mice with MMP inhibitors. We will evaluate cell recruitment in the spaces. We will use optical imaging (with Core C) to study the reactions to microorganisms or their products in models of sterile inflammation, infection or allergic sensitization in vivo, ex vivo and in epithelial cell culture models. We will use mice that have genetic modifications in expression of these genes, concentrating on MMP2, MMP9 and MMP13. We will use mutant mice, specific inhibitors and normal as well as genetically modified epithelial cells in culture to collaborate with Projects 1, 2, 3 and Cores B and C, to investigate the role of of these genes in epithelial wound healing. The immediate implications of this work are in its applications to use of instilled chemoattractant agents and other molecules that modify epithelial defense and will provide proof-of-principle that these critical MMP substrates are potentially efficacious in intervention in epithelial defense mechanisms. Only a thorough understanding of the actions and effects of these enzymes and their major substrates will help mitigate the defense against infection so that recruitment of adequate numbers of inflammatory cells into the spaces beyond the epithelial barrier and the ability of the epithelial to repair itself can be accelerated.