THROMBIN SIGNALING IN HEMOSTASIS AND THROMBOSIS

止血和血栓形成中的凝血酶信号传导

基本信息

批准号：
6527414
负责人：
SHAUN R. COUGHLIN
金额：
$ 36.88万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-05 至 2005-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6527414
关键词：
G protein biological signal transduction cooperative study disease /disorder model fibrin gene targeting genetic models genetically modified animals green fluorescent proteins hemostasis laboratory mouse microcirculation model design /development platelet activation receptor coupling thrombin thrombosis vascular endothelium

项目摘要

DESCRIPTION (Adapted from abstract) This is one of three collaborative ROls submitted in response to RFA HL-99-015 on Arterial Thrombosis. The applicants proposal's overall goal is to define the signaling mechanisms by which platelets are activated, thereby providing a framework for therapeutic development and risk factor identification. The goal of this individual project is to define the role of thrombin signaling in hemostasis and thrombosis. Thrombin activates platelets via proteaseactivated G protein-coupled receptors (PARs). The applicants shall use mice deficient in these receptors to ask: 1) Is thrombin signaling in platelets necessary for normal hemostasis? PAR3 and PAR4 are the thrombin receptors known to participate in mouse platelet activation. It appears that mPAR3 does not mediate transmembrane signaling but instead acts as a cofactor for mPAR4 cleavage and activation by low concentrations o f thrombin. Thus the applicants expect PAR4 to be required for thrombin signaling in mouse platelets. The applicants will use PAR4-deficient mice to test the importance of thrombin signaling in hemostasis. 2) Does attenuation or ablation of thrombin signaling in platelets inhibit thrombosis? Human platelets use PAR1 and PAR4 for thrombin signaling, and it is unknown whether inhibition of PAR1 and/or PAR4 would be useful for preventing or treating thrombosis. PAR3- deficient mouse platelets are analogous to PARl-inhibited human platelets (both rely on PAR4 for thrombin signaling). PAR4-deficient mouse platelets will likely prove analogous to human platelets in which all thrombin signaling has been blocked. The applicants will use PAR3- and PAR4-deficient mice to determine whether partial or complete inhibition of thrombin signaling in platelets protects against arterial and microvascular thrombosis. 3) Is endothelial cell activation by thrombin or other proteases important in hemostasis and thrombosis? The applicants hypothesize that activation of endothelial PAR1 and PAR2 promotes thrombosis and inflammation by promoting platelet and leukocyte rolling and adhesion. The applicants will determine whether mice deficient in PAR1 and/or PAR2 are protected in models of inflammation and microvascular and arterial thrombosis. 4) Do gain-of-function mutations in platelet G protein-coupled receptors (GPCRs) promote thrombosis? The discovery of prothrombotic mutations in genes that regulate cellular behaviors has lagged that in genes encoding the plasma proteins. Several human diseases are mediated by gain-of-function mutations in GPCRs. The applicants will use mice bearing gain-of-function mutations in PAR4 to determine if such GPCR mutations, alone or in combination with mutations in other genes, might be a basis for thrombophilia.

描述（根据摘要改编）这是针对RFA HL-99-015提交的三个协作ROL之一在动脉血栓形成上。申请人提议的总体目标是定义激活血小板的信号传导机制，从而提供治疗发展和危险因素识别框架。目标这个个别项目的是定义凝血酶信号的作用止血和血栓形成。凝血酶通过蛋白酶反应激活血小板 G蛋白偶联受体（PARS）。申请人应使用不足的小鼠这些要问的受体：1）是血小板中凝血酶信号的正常止血？ PAR3和PAR4是已知的凝血酶受体参与小鼠血小板激活。看来MPAR3没有介导跨膜信号传导，而是充当MPAR4的辅因子凝血酶低浓度的裂解和激活。因此申请人期望小鼠中的凝血酶信号需要PAR4 血小板。申请人将使用PAR4缺陷小鼠来测试重要性止血中凝血酶信号的传导。 2）衰减或消融血小板中的凝血酶信号传导抑制血栓形成？人血小板使用PAR1 和PAR4用于凝血酶信号，尚不清楚抑制PAR1 和/或PAR4对于预防或治疗血栓形成很有用。 par3- 缺乏小鼠血小板类似于抑制PAR的人血小板（都依靠PAR4进行凝血酶信号传导）。 PAR4缺陷小鼠血小板所有凝血酶信号传导都可能类似于人血小板已被阻止。申请人将使用Par3-和Par4缺陷小鼠进行确定部分或完全抑制凝血酶信号在血小板可预防动脉和微血管血栓形成。 3）是凝血酶或其他蛋白酶激活内皮细胞在止血和血栓形成？申请人假设激活内皮PAR1和PAR2通过促进促进血栓形成和炎症血小板和白细胞滚动和粘附。申请人将确定缺乏PAR1和/或PAR2的小鼠是否在模型中受到保护炎症以及微血管和动脉血栓形成。 4）做功能奖励血小板G蛋白偶联受体（GPCR）的突变会促进血栓形成？在调节细胞的基因中发现促血栓形成突变行为滞后于编码血浆蛋白的基因。几种人类疾病是由GPCR中功能增益突变介导的。申请人将使用PAR4中有功能收益突变的小鼠确定这种GPCR突变是单独还是与突变结合其他基因可能是血栓形成的基础。