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调节广泛范围的炎症反应， 组织中炎症对于维持正常组织稳态是必不可少的，并且其失调具有 广泛的病理学影响，包括纤维化、瘢痕形成、异常伤口愈合、感染、败血症， 自身免疫性疾病和哮喘。知识上的一个关键差距是理解 纤溶酶原与细胞通讯以调节炎症反应。Plg-RKT是一种新型的一体化膜 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细胞表面 纤溶酶原激活我们实验室的长期目标是了解Plg-RKT 调节生理和病理过程。该提案基于新的数据，表明Plg-RKT 促进CCL 2的表达，CCL 2是促炎症反应的关键介质，也是潜在的干预措施。 点为治疗疾病的炎症成分。其他结果支持挑衅性 CCL 2表达的调节，而不是细胞外基质的细胞表面蛋白水解， 是纤溶酶原/Plg-RKT控制单核细胞募集的主要机制， 体内炎症反应。要解决的中心假设是纤溶酶（原）/Plg-RKT- CCL 2表达的依赖性促进是促进纤溶酶（原）/Plg-RKT-1表达的主要机制。 在炎症反应中依赖单核细胞募集。将在小鼠中检验该假设 胸膜炎和腹膜炎模型。我们将研究Plg-RKT在炎症反应中的作用， 哮喘，因为在辅助性T细胞2型（Th 2）免疫相关疾病，如哮喘，CCL 2表达高 在动物模型中的水平和其中和改善疾病。本提案的目标是 研究Plg-RKT在体内CCL 2合成中的作用，并评估其对Plg-RKT依赖性CCL 2合成的影响。 单核细胞募集和检查Plg-RKT在哮喘发病机制中的作用。我们的具体 目的是（1）研究Plg-RKT在体内CCL 2合成中的作用及其对Plg-RKT依赖性CCL 2合成的影响。 单核细胞募集和（2）检查Plg-RKT在哮喘发病机制中的作用。我们将使用 Plg-RKT缺陷小鼠和过表达Plg-RKT的小鼠，以测试纤溶酶（原）/Plg-RKT依赖性 CCL 2在体内的上调是PAR-1依赖性的。我们将使用单细胞RNA测序来识别细胞类型 负责Plg-RKT依赖性刺激CCL 2表达，我们将确定是否外源性 添加的CCL 2可以挽救Plg-RKT-/-小鼠中巨噬细胞募集的损伤。我们将调查 Plg-RKT在卵白蛋白诱导的哮喘炎症中的作用以及确定Plg-RKT是否调节气道 高反应性（AHR）。我们期望，我们的具体目标的实现将建立Plg-RKT作为一个 通过调节关键化学引诱物CCL 2的表达， 并为单核细胞募集的调节提供了基本的见解。

Project Summary/Abstract The plasminogen activation system extensively regulates the inflammatory response in a broad range of tissues. Inflammation is essential for maintenance of normal tissue homeostasis and its dysregulation has a broad pathologic impact, including development of fibrosis, scarring, aberrant wound healing, infection, sepsis, autoimmune disease and asthma. A critical gap in knowledge is understanding the mechanisms by which plasminogen communicates with cells to regulate inflammatory responses. Plg-RKT is a novel integral membrane protein that binds plasminogen via a C-terminal lysine exposed on the cell surface and promotes cell surface plasminogen activation. The 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 showing that Plg-RKT promotes expression of CCL2, a key mediator of the pro-inflammatory response, and a potential intervention point for the treatment of diseases with an inflammatory component. Additional results support the provocative concept that regulation of CCL2 expression, rather than cell surface proteolysis of extracellular matrix, appears to be the primary mechanism for plasminogen/Plg-RKT control of mononuclear cell recruitment in the inflammatory response in vivo. The central hypothesis to be addressed is that plasmin(ogen)/Plg-RKT- dependent promotion of CCL2 expression is the primary mechanism for promotion of plasmin(ogen)/Plg-RKT- dependent mononuclear cell recruitment in the inflammatory response. The hypothesis will be tested in murine models of pleurisy and peritonitis. And we will investigate the role of Plg-RKT in the inflammatory response in asthma because in T helper type 2 (Th2) immune-related diseases, such as asthma, CCL2 is expressed at high levels and its neutralization in animal models ameliorates disease. The objectives of this proposal are to investigate the role of Plg-RKT in CCL2 synthesis in vivo and assess its impact on Plg-RKT-dependent mononuclear cell recruitment and to examine the role of Plg-RKT in the pathogenesis of asthma. Our specific aims are (1) to investigate the role of Plg-RKT in CCL2 synthesis in vivo and its impact on Plg-RKT-dependent mononuclear cell recruitment and (2) to examine the role of Plg-RKT in the pathogenesis of asthma. We will use Plg-RKT deficient mice and mice over-expressing Plg-RKT to test whether plasmino(ogen)/Plg-RKT-dependent CCL2 up-regulation in vivo is PAR-1- dependent. We will use single cell RNA sequencing to identify cell types responsible for Plg-RKT-dependent stimulation of CCL2 expression and we will determine whether exogenously added CCL2 can rescue the impairment in macrophage recruitment in Plg-RKT-/- mice. We will investigate the role of Plg-RKT in inflammation in ovalbumin-induced asthma and determine whether Plg-RKT regulates airway hyper-responsiveness (AHR). We expect that accomplishment of our specific aims will establish Plg-RKT as a pivotal regulator of the inflammatory response via regulation of expression of the key chemoattractant, CCL2, and provide fundamental insights into how mononuclear cell recruitment is regulated.