Regulation of cellular functions by the plasminogen receptor, Plg-RKT

项目摘要/摘要 纤溶酶原激活系统广泛地调节组织重塑以及 广泛的组织中的炎症。这些过程的失调具有广泛的病理影响，包括 伤口愈合异常(慢性未愈合伤口是糖尿病的主要组成部分)，肺和心血管纤维化， 疤痕、感染、败血症和自身免疫性疾病。知识中的一个关键差距是对如何 纤溶酶原通过与细胞沟通来调节这些过程。PLG受体PLG-RKT是一种新型的整体膜 通过暴露在细胞表面的C端赖氨酸与纤溶酶原结合并促进纤溶酶原激活的蛋白质 在细胞表面。我们实验室广泛而长期的目标是了解PLG-RKT调节机制。 生理和病理过程。这一建议是基于在PLG-RKT缺陷小鼠身上获得的新数据 支持PLG-RKT在生理性细胞外基质重塑和炎症调控中的关键作用 以及病理环境，特别是在皮肤伤口的愈合方面。这项提案目的是界定具体的 伤口愈合过程中需要PLG-RKT活性的几个步骤，并确定PLG-RKT通过何种机制- RKT规定了这些具体步骤。需要解决的中心假设是，PLG-RKT是实现 伤口愈合正常。为了解决我们的假设，我们的具体目标是：(1)确定具体的机制，通过 PLG-RKT调节伤口愈合；(2)研究巨噬细胞PLG-RKT调节伤口愈合的具体机制 发炎。伤口愈合研究将在PLG-RKT全局缺失的小鼠、具有以下两种情况之一的小鼠身上进行 巨噬细胞或角质形成细胞特异性缺失PLG-RKT，同时缺失PLG-RKT和纤维蛋白原的小鼠，以及 小鼠过表达PLG-RKT。将对伤口组织进行PLG积聚、细胞因子诱导和异常分析 中性粒细胞、胶原和纤维蛋白堆积。用PLG-RKT-/-和PLG-RKT+/+巨噬细胞进行的体外实验将测试 巨噬细胞PLG-RKT在纤溶酶依赖的细胞因子释放、细胞内信号转导和胞吐中的作用。和一个 蛋白质组学方法将被用于PLG-RKT相互作用组的交互作用。我们期望实现我们的特定目标 AIMS将建立PLG-RKT作为伤口愈合的关键调节因素，并提供关于如何启动的基本见解 炎症的消退和组织重塑在伤口愈合过程中受到调节。这些新的见解预计将 对理解广泛的病理和生理过程具有重大影响 有效的炎症反应，需要组织重塑。此外，要获得的结果可以识别 治疗组织重塑和调节失调疾病的潜在新靶点 发炎。

Project Summary/Abstract The plasminogen activation system extensively regulates tissue remodeling and both the initiation and resolution of inflammation in a broad range of tissues. Dysregulation of these processes has a broad pathologic impact, including aberrant wound healing (chronic unhealed wounds are a major component of diabetes), lung and cardiovascular fibrosis, scarring, infection, sepsis, and autoimmune disease. A critical gap in knowledge is the understanding of how plasminogen communicates with cells to regulate these processes. The Plg receptor, Plg-RKT, is a novel integral membrane protein that binds plasminogen via a C-terminal lysine exposed on the cell surface and promotes plasminogen activation on the cell surface. The broad, long-term goal of our laboratory is to understand mechanisms by which Plg-RKT regulates physiologic and pathologic processes. This proposal is based on new data obtained with Plg-RKT deficient mice that support a pivotal role for Plg-RKT in the regulation of extracellular matrix remodeling and inflammation in physiological and pathological settings, particularly in healing of cutaneous wounds. The objective of this proposal is to define specific steps in the wound healing process at which the activity of Plg-RKT is necessary and to identify mechanisms by which Plg- RKT regulates these specific steps. The central hypothesis to be addressed is that Plg-RKT is necessary to accomplish normal wound healing. To address our hypothesis our specific aims are: (1) to identify specific mechanisms by which Plg-RKT regulates wound healing and (2) to investigate specific mechanisms by which macrophage Plg-RKT regulates inflammation. Wound healing studies will be performed in mice with global deletion of Plg-RKT, mice with either macrophage- or keratinocyte-specific deletion of Plg-RKT, mice with global deletion of both Plg-RKT and fibrinogen, and mice over-expressing Plg-RKT. Wound tissue will be analyzed for Plg accumulation, cytokine induction, and aberrant neutrophil, collagen and fibrin accumulation. In vitro experiments with Plg-RKT-/- and Plg-RKT+/+ macrophages will test the role of macrophage Plg-RKT in plasmin-dependent cytokine release, intracellular signaling and efferocytosis. And a proteomic approach will be used to interogate the Plg-RKT interactome. We expect that accomplishment of our specific aims will establish Plg-RKT as a pivotal regulator of wound healing and provide fundamental insights into how initiation and resolution of inflammation and tissue remodeling are regulated in wound healing. These new insights are expected to have a major impact on the understanding of a broad array of pathological and physiological processes requiring an effective inflammatory response and requiring tissue remodeling. Furthermore, the results to be obtained may identify new potential therapeutic targets for the treatment of diseases with dysregulated tissue remodeling and dysregulated inflammation.