Variation in platelet function: human PAR4 functional genomics

血小板功能的变异：人类 PAR4 功能基因组学

基本信息

批准号：
9476112
负责人：
PAUL F. BRAY
金额：
$ 40.48万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-26 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9476112
关键词：
Accounting African Agonist Alleles Antiplatelet Drugs Aspirin Biology Black race Blood Blood Platelet Antagonists Blood Platelets Blood donor Brain Cardiovascular Diseases Cardiovascular system Cell Line Cells Clinical Clinical Trials Coronary heart disease Data Disease Dominant-Negative Mutation Dose Economic Factors Ethnic group Event Exhibits F2R gene FDA approved Funding Gene Expression Gene Frequency Generations Genes Genetic Genotype Goals Heart Hemorrhage Homozygote Human Incidence Individual Knowledge Liver Mediating Medicine MicroRNAs Modeling Molecular Molecular Genetics Nature Outcome PAWR gene Patients Pharmacogenetics Pharmacology Physiological Platelet Activation Platelet aggregation Population Protein Isoforms Proteins Race Residual state Resistance Risk Risk Factors Sampling Secondary Prevention Signal Pathway Signal Transduction Testing Thrombin Thrombus Tissues Variant Work base cardiovascular disorder prevention clinical development clinical risk experimental study functional genomics genetic variant improved inhibitor/antagonist inter-individual variation novel phosphatidylcholine transfer protein preclinical development public health relevance racial difference release of sequestered calcium ion into cytoplasm response shear stress

项目摘要

DESCRIPTION (provided by applicant): This application is a resubmission of a competitive renewal of HL102482 "Variation in platelet function: the genetics of platelet gene expression." The work resulting from this funding included discoveries that (1) platelets from black subjects have greater PAR4-mediated platelet aggregation to thrombin, (2) a novel platelet protein, phosphatidylcholine transfer protein (PC-TP) contributed to this racial difference, and (3) the microRNA miR- 376c regulated PC-TP levels (Edelstein et al., Nature Medicine, 2013). Our pursuit of the molecular genetic basis of the racial difference in platelet aggregation led to the discovery of a common, racially divergent variant in F2RL3 (encodes PAR4) that induces an Ala120Thr substitution, accounting for ~50% of the racial difference in PAR4 reactivity. The PAR4 Thr120 variant is associated with greater PAR4-AP-induced platelet aggregation and IP generation in transfected cell lines. Additional preliminary data indicates that black race confers relative 3 resistance to COX and P2Y inhibition, and the Thr120 variant confers relative resistance to the FDA-approved 12 PAR1 inhibitor, vorapaxar, via enhanced thrombin responsiveness through PAR4. Furthermore, PAR4 Thr120- positive platelets - and especially homozygotes (40% of black subjects) - show resistance to inhibition by a novel PAR4 antagonist, YD-3. These data suggest that compared to white patients with cardiovascular disease, black patients may receive less benefit from most FDA-approved anti-platelet agents. The goals of this renewal application are to characterize the differential signaling, pharmacogenetic and clinical outcomes of F2RL3 variants, and identify novel PAR4 Thr120 antagonists. Aim 1 will characterize (a) differences in PAR4 Ala120Thr variant thrombin-induced signaling and shear-induced aggregation, and (b) the dominant-negative effects of a second PAR4 Phe296Val variant. Aim 2 will characterize the effect of PAR4 variants on thrombin- induced platelet aggregation in the presence of (a) anti-platelet agents (aspirin, P2Y inhibitor and vorapaxar) 12 and (b) a class of PAR4 inhibitors in clinical or pre-clinical development. Aim 3a will test for F2RL3 SNPs as risk factors for ischemic cardiovascular events in public GWASs of ~80,000 subjects. In Aim 3b we will genotype ~6,000 samples from the TRACER study and test for associations between F2RL3 SNPs and both ischemic cardiovascular and bleeding outcomes in patients receiving vorapaxar. Because current models of platelet signaling are likely based primarily on experiments using blood from white donors, and because we know the F2RL3 allele frequencies in all races/ethnic groups, successful completion of these Aims will substantively broaden basic understanding of platelet biology, develop variant-specific PAR4 inhibitors that could improve cardiovascular outcomes for PAR4 Thr120-positive patients (~86% African ancestry and 36% non-African ancestry), and may provide a rational basis for decisions about use and/or dosing of new PAR1 inhibitors based on patient race and/or F2RL3 genotypes.

描述（由申请人提供）：本申请是 HL102482“血小板功能的变异：血小板基因表达的遗传学”的竞争性更新的重新提交。这项资助的工作包括以下发现：(1) 来自黑人受试者的血小板具有更大的血小板功能。 PAR4 介导的血小板聚集为凝血酶，(2) 一种新型血小板蛋白，磷脂酰胆碱转移蛋白 (PC-TP) 促成了这一种族(3) microRNA miR-376c 调节 PC-TP 水平（Edelstein 等人，Nature Medicine，2013）我们对血小板聚集种族差异的分子遗传基础的探索导致了一个共同的发现： F2RL3（编码 PAR4）中存在种族差异的变异体，可诱导 Ala120Thr 取代，约占 PAR4 反应性种族差异的 50%。 Thr120 变异与转染细胞系中 PAR4-AP 诱导的血小板聚集和 IP 生成增加相关。其他初步数据表明黑人种族具有这一特征。 3 对 COX 和 P2Y 抑制具有相对抗性，Thr120 变异通过 PAR4 增强凝血酶反应性，赋予对 FDA 批准的 12 PAR1 抑制剂沃拉帕沙 (vorapaxar) 的相对抗性。此外，PAR4 Thr120 阳性血小板，尤其是纯合子（40% 的黑人）。受试者） - 对新型 PAR4 拮抗剂 YD-3 的抑制表现出抵抗力。这些数据表明，与患有心血管疾病的白人患者相比，黑人患者可能会接受治疗。该更新申请的目标是表征 F2RL3 变体的差异信号传导、药物遗传学和临床结果，并鉴定新型 PAR4 Thr120 拮抗剂，以表征 (a) PAR4 的差异。 Ala120Thr 变体凝血酶诱导的信号传导和剪切诱导的聚集，以及 (b) 第二个 PAR4 Phe296Val 变体的显性负效应将表征 Aim 2。目的 3a 将研究在 (a) 抗血小板药物（阿司匹林、P2Y 抑制剂和 vorapaxar）12 和 (b) 一类 PAR4 抑制剂存在的情况下 PAR4 变体对凝血酶诱导的血小板聚集的影响。在目标 3b 中，我们在约 80,000 名受试者的公共 GWAS 中测试 F2RL3 SNP 作为缺血性心血管事件的危险因素。将对 TRACER 研究中的约 6,000 个样本进行基因分型，并测试 F2RL3 SNP 与接受 vorapaxar 的患者的缺血性心血管和出血结果之间的关联，因为当前的血小板信号传导模型可能主要基于使用白人捐赠者血液的实验，并且因为我们知道。所有种族/民族中的 F2RL3 等位基因频率，成功完成这些目标将大大拓宽对血小板生物学的基本了解，开发可以改善心血管结局的变体特异性 PAR4 抑制剂PAR4 Thr120 阳性患者（约 86% 非洲血统和 36% 非非洲血统），并且可能为根据患者种族和/或 F2RL3 基因型决定新 PAR1 抑制剂的使用和/或剂量决策提供合理基础。