PROTEASE-ACTIVATED RECEPTORS IN EMBRYONIC DEVELOPMENT

胚胎发育中的蛋白酶激活受体

• 批准号: 6390869
• 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
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-30 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6390869
• 关键词: G protein coupled receptor kinase; biological signal transduction; blood coagulation; blood vessels; cell type; developmental genetics; electron microscopy; embryo /fetus tissue /cell culture; embryogenesis; fibrinogen; gene targeting; genetic enhancer element; genetic promoter element; genetically modified animals; histochemistry /cytochemistry; histogenesis; in situ hybridization; laboratory mouse; messenger RNA; protein structure function; receptor expression; serine proteinases; thrombin receptor; thrombomodulin; vascular endothelium

DESCRIPTION: (Adopted from the Applicant's abstract.) The long-term goal of this research is to understand the role of the coagulation system in development. Considerable evidence exists from knock-outs of components of that system that it has an important role in embryogenesis, including evidence from PAR-1 knock-out, which leads to the demise of approximately half of PAR1-deficient embryos at aboutE9.5. Death of these embryos was associated with bleeding but could not be attributed to defects in platelet function, implying that thrombin signaling may have a role in embryonic development unrelated to its role in hemostasis, at least in the usual sense. In situ hybridization revealed PAR1 mRNA expression in endocardial and endothelial cells at E9.5, suggesting that PAR1 signaling might be important for normal blood vessel development and vascular integrity. The Principal Investigator postulates that the coagulation cascade functions in part as a "leak detector" that monitors and regulates the integrity of developing blood vessels. To test these hypotheses he proposes the following specific aims. Aim 1 will ask the question: In which cell type(s) is PAR1 signaling important for embryonic development? To address this question they will: a) Use a lacZ knock-in to identify the cell types that express PAR1 and determine their fate in PAR1-deficient embryos; b) Characterize vascular development in PAR1-deficient embryos; c) determine by transgenic rescue whether lack of PAR1 function in endothelial cells is the primary defect in PAR1-deficient embryos; d) Use knock-in of gain-of-function mutations to identify the cells in which PAR1 activation normally occurs during embryonic development; e) Test the hypothesis that disinhibited thrombin production and PAR1 signaling are responsible for the death of thrombomodulin-deficient embryos. In Aim 2, they ask the question: Beyond PAR1, what are the other effectors of the coagulation cascade during embryonic development? They will: a) Test the hypothesis that fibrinogen becomes important in the absence of PAR1, b) Determine whether PAR4 and/or as yet unidentified receptors provide "back-up" thrombin signaling in embryonic development, c) Determine the effect of PAR2 deficiency in combination with other PAR-deficiencies on embryonic development.

描述：（摘自申请人的摘要。）长期目标 本研究旨在了解凝血系统在 发展。大量证据来自于其组件的敲除 系统表明它在胚胎发生中具有重要作用，包括来自 PAR-1 基因敲除，导致大约一半的死亡 PAR1缺陷胚胎大约在E9.5。这些胚胎的死亡与 出血但不能归因于血小板功能缺陷，这意味着 凝血酶信号传导可能在与胚胎发育无关的胚胎发育中发挥作用 它在止血中的作用，至少在通常意义上是这样。原位杂交 揭示了 E9.5 时心内膜和内皮细胞中 PAR1 mRNA 的表达， 表明 PAR1 信号传导可能对正常血管很重要 发育和血管完整性。首席研究员假设 凝血级联部分起到监测“泄漏检测器”的作用 并调节发育中血管的完整性。为了测试这些 他提出以下具体目标的假设。目标 1 将询问 问题： PAR1 信号传导在哪些细胞类型中对胚胎很重要 发展？为了解决这个问题，他们将： a) 使用 lacZ 敲入 识别表达 PAR1 的细胞类型并决定它们的命运 PAR1缺陷胚胎； b) PAR1 缺陷的血管发育特征 胚胎； c) 通过转基因拯救确定 PAR1 功能是否缺乏 内皮细胞是 PAR1 缺陷胚胎的主要缺陷； d) 使用 敲入功能获得突变以鉴定 PAR1 所在的细胞 激活通常发生在胚胎发育过程中； e) 检验假设 凝血酶产生和 PAR1 信号传导被抑制 缺乏血栓调节蛋白的胚胎死亡。在目标 2 中，他们提出了以下问题： 除了 PAR1 之外，凝血级联的其他效应器还有哪些？ 胚胎发育？他们将： a) 检验纤维蛋白原的假设 在没有 PAR1 的情况下变得重要，b) 确定 PAR4 和/或是否作为 然而，未知的受体在胚胎中提供“备用”凝血酶信号传导 c) 确定 PAR2 缺乏症与 胚胎发育中的其他 PAR 缺陷。