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（改编自摘要）这是响应 RFA HL-99-015 提交的三个协作 RO 之一关于动脉血栓形成。申请人提案的总体目标是定义血小板被激活的信号传导机制，从而提供治疗开发和危险因素识别的框架。目标这个单独项目的目的是定义凝血酶信号传导在止血和血栓形成。凝血酶通过蛋白酶激活血小板 G 蛋白偶联受体 (PAR)。申请人应使用缺乏这些受体要问：1）血小板中的凝血酶信号传导对于正常止血吗？ PAR3 和 PAR4 是已知的凝血酶受体参与小鼠血小板活化。 mPAR3 似乎没有介导跨膜信号转导，但充当 mPAR4 的辅助因子低浓度凝血酶的裂解和激活。因此申请人预计 PAR4 是小鼠凝血酶信号传导所必需的血小板。申请人将使用PAR4缺陷小鼠来测试其重要性凝血酶信号传导在止血中的作用。 2) 是否衰减或消融血小板中的凝血酶信号传导抑制血栓形成？人类血小板使用 PAR1 和 PAR4 参与凝血酶信号传导，目前尚不清楚是否抑制 PAR1 和/或PAR4可用于预防或治疗血栓形成。 PAR3- 缺陷小鼠血小板类似于 PAR1 抑制的人血小板（两者都依赖 PAR4 进行凝血酶信号传导）。 PAR4 缺陷小鼠血小板可能会被证明与人类血小板类似，其中所有凝血酶信号传导已被阻止。申请人将使用 PAR3 和 PAR4 缺陷小鼠确定凝血酶信号传导是否部分或完全抑制血小板可防止动脉和微血管血栓形成。 3) 是凝血酶或其他重要的蛋白酶激活内皮细胞止血和血栓？申请人假设激活内皮 PAR1 和 PAR2 通过促进血栓形成和炎症血小板和白细胞滚动和粘附。申请人将决定缺乏 PAR1 和/或 PAR2 的小鼠在模型中是否受到保护炎症以及微血管和动脉血栓形成。 4）进行功能获得血小板G蛋白偶联受体（GPCR）突变会促进血栓形成吗？调节细胞基因中促血栓突变的发现行为滞后于编码血浆蛋白的基因。多种人类疾病是由 GPCR 的功能获得性突变介导的。申请人将使用携带 PAR4 功能获得性突变的小鼠来确定此类 GPCR 突变是单独的还是与以下突变组合：其他基因，可能是血栓形成倾向的基础。