Regulation of Renal Injury and Fibrosis by the Plasminogen Receptor, Plg-RKT

纤溶酶原受体 Plg-RKT 对肾损伤和纤维化的调节

• 批准号: 10265354
• 负责人: ROBERT J PARMER
• 金额: --
• 依托单位: VA SAN DIEGO HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10265354
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Adult; Affect; Anti-Inflammatory Agents; Binding Sites; Cardiovascular Diseases; Cause of Death; Cell Cycle; Cell physiology; Cell surface; Cells; Cessation of life; Chronic Kidney Failure; Data; Deposition; Disease; EGF gene; End stage renal failure; Enzyme Precursors; Epithelial Cells; Equilibrium; Exhibits; Extracellular Matrix; Fibrin; Fibrinogen; Fibrosis; Frequencies; G2/M Arrest; Growth Factor; Healthcare Systems; Impairment; In Vitro; Infiltration; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Injury; Injury to Kidney; Kidney; Kidney Diseases; Lymphocyte; Mediating; Molecular; Monitor; Mus; Myofibroblast; Pathologic Processes; Pathway interactions; Patients; Phagocytosis; Phase; Phenotype; Physiological Processes; Plasmin; Plasminogen; Play; Population; Process; Proteins; Proteomics; Reagent; Regulation; Renal Tissue; Resolution; Risk Factors; Role; Signal Pathway; Signal Transduction; Site; System; Testing; Time; Tissues; Tubular formation; Urokinase Plasminogen Activator Receptor; Work; base; confocal imaging; cytokine; disability; fibrogenesis; genetic approach; imaging study; improved; in vivo; insight; kidney fibrosis; macrophage; mouse model; neutrophil; new therapeutic target; novel; patient population; plasminogen receptor; premature; recruit; repaired; response; tissue injury; tissue repair

Chronic kidney disease (CKD) has emerged as a silent killer that affects a large segment (15-20%) of the adult population, and is a major risk factor for end-stage renal disease (ESRD), as well as acute kidney injury, cardiovascular disease, and premature death. Progressive tubulointerstitial fibrosis is the final common pathway for all kidney diseases leading to CKD. However, the molecular mechanisms and regulatory steps that govern and modulate tubulointerstitial fibrogenesis are not fully understood. The response to tissue injury involves an ordered sequence of partially overlapping phases: inflammatory, proliferation, and extracellular matrix (ECM) remodeling. Previous work has focused on and demonstrated the key role of macrophages in the response to renal injury, with distinct macrophage subsets regulating the balance of renal injury, inflammation, repair, and fibrosis. Results also have shown a key role for tubular epithelial cells (TECs) in renal fibrogenesis. TECs undergo marked phenotypic changes in acute injury and contribute to both inflammatory and pro-fibrotic phases. Recent and very exciting work suggests a critical role for plasminogen (Plg) and the Plg activation system in macrophage function and macrophage involvement in tissue repair, including promotion of key steps in macrophage phagocytosis and signaling. Results also suggest a direct role for Plg in regulating TEC function, including key TEC phenotypic changes and signaling in response to renal injury. This proposal is based on our proteomics-based discovery of a new protein, the plasminogen receptor, Plg-RKT, which markedly enhances the activation of the zymogen Plg to plasmin, as well as concentrates and localizes the proteolytic activity of plasmin at specific sites on the cell surface. We have observed prominent expression of Plg-RKT in macrophages and TECs. We have developed Plg-RKT-/- mouse models, and in recent studies have demonstrated that Plg-RKT plays a major role in macrophage recruitment and function in response to inflammatory stimulation. In addition, Plg-RKT-/- mice exhibit impaired tissue remodeling and impaired fibrin degradation leading to fibrosis in several in vivo settings. Of note, in recent preliminary studies, we have observed marked increases in renal fibrosis in Plg-RKT-/- mice compared to Plg-RKT+/+ mice in response to acute renal injury. In addition, we have observed that Plg-RKT expression is substantially altered in response to experimental renal injury, and in patients with CKD. The overall objectives of this proposal are to test the hypothesis that Plg-RKT plays a major role in the modulation of renal fibrosis in response to renal injury, and to delineate the specific mechanisms and pathways that mediate the effect of Plg-RKT on renal ECM remodeling and repair. We will use a genetic approach to examine the role of cell-specific Plg-RKT in renal ECM remodeling and the modulation of renal fibrosis in vivo. We will perform studies in Plg-RKT-/- and Plg-RKT+/+ mice, mice in which Plg-RKT is deleted in specific cells, including macrophages and TECs, and mice in which Plg-RKT and fibrinogen are concomitantly deleted, allowing us to examine the role of Plg-RKT at defined steps in the renal injury, remodeling, and fibrosis phases. In addition, we will investigate the role of macrophage and TEC Plg-RKT in key cellular steps that regulate renal ECM remodeling and fibrosis at the cellular level, including regulation of release of pro-inflammatory and anti-inflammatory cytokines from macrophages and TECs, regulation of intracellular signaling pathways, regulation of macrophage phagocytosis, and regulation of key TEC phenotypic changes in response to renal injury. This project seeks to provide new information on Plg- RKT as a pivotal regulator of renal ECM remodeling and repair, with important implications not only for renal fibrosis and CKD, but also a broad array of diseases characterized by dysregulated tissue remodeling and inflammation.

慢性肾脏疾病（CKD）已成为一种沉默的杀手，影响了大部分（15-20％）的成人 人口，是终末期肾脏疾病（ESRD）的主要危险因素，也是急性肾脏损伤， 心血管疾病和过早死亡。渐进的微管间质纤维化是最终常见 所有导致CKD的肾脏疾病的途径。但是，分子机制和调节步骤 尚未完全了解主管和调节微管间质纤维发生。对组织损伤的反应 涉及部分重叠阶段的有序序列：炎症，增殖和细胞外 矩阵（ECM）重塑。以前的工作重点是并证明了巨噬细胞在 对肾脏损伤的反应，具有不同的巨噬细胞子集，调节肾脏损伤，炎症的平衡， 修复和纤维化。结果还显示了管状上皮细胞（TEC）在肾纤维发生中的关键作用。 TEC经历了急性损伤的明显表型变化，并导致炎症和促纤维化 阶段。最近且非常令人兴奋的工作表明纤溶酶原（PLG）和PLG激活至关重要 巨噬细胞功能的系统和巨噬细胞参与组织修复，包括促进关键步骤 在巨噬细胞吞噬作用和信号传导中。结果还表明PLG在调节TEC中的直接作用 功能，包括响应肾脏损伤的关键TEC表型变化和信号传导。该提议是 基于我们基于蛋白质组学的发现，对新蛋白质的纤溶酶原受体PLG-RKT的发现，该蛋白 明显地增强了酶原PLG对纤溶酶的激活，并浓缩并定位 纤溶酶在细胞表面的特定位点的蛋白水解活性。我们观察到了 巨噬细胞和TEC中的PLG-RKT。我们已经开发了PLG-RKT - / - 小鼠模型，并且在最近的研究中 已经证明PLG-RKT在巨噬细胞募集和功能中起着重要作用 炎症刺激。此外，PLG-RKT - / - 小鼠表现出受损的组织重塑和纤维蛋白受损 降解导致几种体内环境中的纤维化。值得注意的是，在最近的初步研究中，我们有 与PLG-RKT+/+小鼠相比 急性肾脏损伤。此外，我们已经观察到PLG-RKT表达在响应中大大改变 进行实验性肾脏损伤，以及CKD患者。该提案的总体目标是测试 假设PLG-RKT在肾脏损伤的肾纤维化调节中起主要作用 描述介导PLG-RKT对肾脏ECM重塑的影响的特定机制和途径 和维修。我们将使用一种遗传方法来检查细胞特异性PLG-RKT在肾脏ECM中的作用 重塑和体内肾纤维化的调节。我们将在PLG-RKT - / - 和PLG-RKT+/+进行研究 小鼠，在特定细胞中删除PLG-RKT的小鼠，包括巨噬细胞和TEC，以及其中的小鼠 PLG-RKT和纤维蛋白原被删除，使我们能够检查PLG-RKT在定义步骤中的作用 在肾脏损伤中，重塑和纤维化阶段。此外，我们将研究巨噬细胞的作用和 tec plg-rkt在关键细胞步骤中调节肾脏ECM重塑和纤维化在细胞水平， 包括调节巨噬细胞的促炎和抗炎细胞因子的释放 TEC，细胞内信号通路的调节，巨噬细胞吞噬作用的调节以及调节 关键的TEC表型响应于肾脏损伤。该项目旨在提供有关PLG-的新信息 RKT是肾脏ECM重塑和修复的关键调节剂，不仅对肾脏具有重要意义 纤维化和CKD，但也有多种疾病，这些疾病的特征是组织重塑和 炎。