PAR4 mediates platelet activation in venous thromboembolism

PAR4介导静脉血栓栓塞中的血小板活化

• 批准号: 10794920
• 负责人: Elizabeth Ann Knauss
• 金额: $ 4.65万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10794920
• 关键词: Affect; Agonist; Alleles; Anticoagulants; Antiplatelet Drugs; Binding Sites; Biological Markers; Blood; Blood Platelets; Blood flow; Cancer Patient; Cardiovascular Diseases; Cessation of life; Clinical; Clinical Trials; Coagulation Process; Complication; Data; Development; Disease; Endothelial Cells; Erythrocytes; Exhibits; Fibrin; Functional disorder; G-Protein-Coupled Receptors; Generations; Genetic Polymorphism; Goals; Hemorrhage; Human; Individual; Inflammatory; Knock-in Mouse; Ligand Binding; Mediating; Meta-Analysis; Microfluidics; Modeling; Mus; Mutation; New Agents; Onset of illness; Pathway interactions; Patients; Peptides; Platelet Activation; Play; Prevention; Preventive measure; Process; Publications; Pulmonary Embolism; Recurrence; Relative Risks; Research; Research Personnel; Risk; Risk Factors; Risk Reduction; Role; Safety; Serine; Severities; Signal Transduction; Single Nucleotide Polymorphism; Surface; Testing; Therapeutic; Thrombin; Thrombophilia; Thrombosis; Thrombus; Variant; Venous Thrombosis; Work; chemotherapy; clinical application; extracellular; genome wide association study; improved; in vivo; insight; knock-down; mouse model; mouse protease-activated receptor 4; neutrophil; new therapeutic target; pharmacologic; platelet function; prevent; promoter; protease-activated receptor 3; protease-activated receptor 4; receptor; response; small molecule inhibitor; thrombotic; training opportunity; venous thromboembolism

PROJECT SUMMARY/ABSTRACT Venous thrombosis (VT) and its major complication, pulmonary embolism (PE), are often grouped together as venous thromboembolism (VTE). This disease affects nearly 600,000 individuals per year and is the leading cause of end-stage cardiovascular disease and death. VT is promoted by three major factors, known as Virchow’s triad: hypercoagulability, endothelial cell dysfunction, and stasis of blood flow. It is now recognized that platelets play a critical initiating role, and the mechanism is just now being uncovered. Hypercoagulation and thrombin generation are major risk factors for VT, and thrombin-activated protease activated receptor 4 (PAR4) promotes procoagulant platelets, phosphatidyl serine (PS) exposure, and subsequent thrombin generation. I propose that platelet PAR4 is an important contributor to VTE. The scientific premise of this proposal is based my preliminary data showing that a hypo-reactive PAR4 single nucleotide polymorphism (SNP) (PAR4- P310L) located in extracellular loop 3 of PAR4 is associated with a lower risk for VTE in a GWAS meta-analysis. Further, mouse platelets with a homologous PAR4-P322L polymorphism exhibit decreased aggregation in response to thrombin activation and ultimately show decreased PAR4 receptor reactivity. The goals of this proposal are 1) to determine how PAR4 contributes to VT initiation and propagation using complementary mouse models, 2) validate PAR4 as a target to treat VT 3) define how PAR4 modulates platelet function in VT. I hypothesize that PAR4 signaling on platelets is a driver of VT, and reduced PAR4 signaling or pharmacological inhibition will offer protection from VTE. I aim to determine the role of PAR4 in the initiation and propagation of venous thrombosis. I will use 3 complementary mouse models of VT to establish PAR4 as a major contributor of clot development under different thrombotic conditions. In order to determine the level of PAR4 reactivity necessary for thrombus propagation, I will use 3 mouse models with differing levels of PAR4 activity: wild-type, PAR4-P322L mimicking the human SNP, and PAR4 -/- to completely remove PAR4. Additionally, this proposal aims to define how PAR4 activation modulates platelet response in VTE. I will use human blood in microfluidic chambers as well as mouse models with varying levels of PAR4 reactivity described above to determine how PAR4 influences the development of VT. Upon completion, this proposal will identify an undetermined mechanism behind PAR4-mediated platelet procoagulant activity in VTE, which can provide a novel therapeutic target for patients with VTE.

项目摘要/摘要 静脉血栓形成（VT）及其主要并发症，肺栓塞（PE），通常被分组为 静脉血栓栓塞（VTE）。这种疾病每年影响近60万人，是领导者 终阶段心血管疾病和死亡的原因。 VT由三个主要因素（称为）促进 Virchow的三合会：高凝性，内皮细胞功能障碍和血液流动的停滞。现在被认可 该血小板起着至关重要的发挥作用，而该机制刚刚被发现。高凝 凝血酶生成是VT的主要危险因素，凝血酶激活的蛋白酶活化受体4 （PAR4）促进促凝血小板，磷脂酰丝氨酸（PS）暴露和随后的凝血酶 一代。我建议血小板PAR4是VTE的重要贡献者。该提议的科学前提 是基于我的初步数据，表明低反应性PAR4单核苷酸多态性（SNP）（PAR4-- 位于PAR4的细胞外环3中的p310l）与GWAS荟萃分析中VTE的风险较低有关。 此外，具有同源PAR4-P322L多态性的小鼠血小板在 对凝血酶激活的反应并最终显示出PAR4受体反应性降低。目标的目标 提案是1）确定PAR4如何使用互补小鼠对VT的启动和繁殖贡献 模型，2）验证PAR4作为处理VT的目标3）定义PAR4如何调节VT中的血小板功能。我 假设血小板上的PAR4信号是VT的驱动器，并且PAR4信号或药理降低 抑制作用将提供免受VTE的保护。我旨在确定PAR4在主动性和传播中的作用 静脉血栓形成。我将使用3种完整的VT鼠标模型来建立PAR4作为 在不同的血小板条件下，凝块发育。为了确定PAR4反应性的水平 对于血栓繁殖所需的必要 PAR4-P322L模仿人SNP，然后par4 - / - 完全删除PAR4。此外，此提案 旨在定义PAR4激活如何调节VTE中的血小板响应。我将在微流体中使用人类血液 腔室以及具有不同水平的PAR4反应性的小鼠模型，以确定如何确定 PAR4影响VT的发展。完成后，该提案将确定一个不确定的 PAR4介导的VTE中PAR4介导的血小板突出活性的机制，该血小板可提供新的疗法 VTE患者的靶标。