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

项目总结/摘要 纤溶酶原激活系统广泛地调节组织重塑以及纤溶酶原激活的起始和消退。 广泛组织中的炎症。这些过程的失调具有广泛的病理影响，包括 异常伤口愈合（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的一个关键差距是理解如何 纤溶酶原与细胞通讯以调节这些过程。Plg受体，Plg-RKT，是一种新的整合膜 通过暴露在细胞表面的C-末端赖氨酸结合纤溶酶原并促进纤溶酶原活化的蛋白质 在细胞表面。我们实验室广泛的长期目标是了解Plg-RKT调节的机制。 生理和病理过程。该提议基于从Plg-RKT缺陷小鼠获得的新数据， 支持Plg-RKT在调节生理性细胞外基质重塑和炎症中的关键作用， 和病理环境，特别是在皮肤伤口的愈合中。本提案的目的是确定具体的 在创伤愈合过程中Plg-RKT的活性是必需的步骤，并鉴定Plg-RKT的作用机制。 RKT规范这些具体步骤。要解决的中心假设是，Plg-RKT是必要的， 伤口正常愈合为了解决我们的假设，我们的具体目标是：（1）确定特定的机制， Plg-RKT调节伤口愈合和（2）研究巨噬细胞Plg-RKT调节伤口愈合的特定机制。 炎症伤口愈合研究将在Plg-RKT整体缺失的小鼠、Plg-RKT整体缺失的小鼠、Plg-RKT整体缺失的小鼠、Plg-RKT整体缺失的小鼠、Plg-RKT整体缺失的小鼠或Plg-RKT整体缺失的小鼠中进行。 巨噬细胞或角化细胞特异性Plg-RKT缺失，Plg-RKT和纤维蛋白原均缺失的小鼠，和 过表达Plg-RKT的小鼠。将分析伤口组织的Plg积累、细胞因子诱导和异常的细胞因子诱导。 中性粒细胞、胶原蛋白和纤维蛋白积聚。使用Plg-RKT-/-和Plg-RKT +/+巨噬细胞的体外实验将测试 巨噬细胞Plg-RKT在纤溶酶依赖性细胞因子释放、细胞内信号传导和巨噬细胞吞噬中的作用。和 蛋白质组学方法将用于研究Plg-RKT相互作用组。我们希望我们的具体目标能够实现， 目的将建立Plg-RKT作为伤口愈合的关键调节剂，并提供如何启动的基本见解 并且在伤口愈合中调节炎症的消退和组织重塑。这些新的见解预计将 对理解广泛的病理和生理过程有重大影响， 有效的炎症反应并需要组织重塑。此外，要获得的结果可以识别 用于治疗具有失调的组织重塑和失调的疾病的新的潜在治疗靶点 炎症

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.