PROTEASE-ACTIVATED RECEPTORS IN EMBRYONIC DEVELOPMENT

描述：(摘自申请人的摘要。)的长期目标是 本研究旨在了解凝血系统在血液中的作用。 发展。相当多的证据来自于对其中一些成分的敲除 它在胚胎发育中发挥重要作用的系统，包括来自 PAR-1基因敲除，导致大约一半的 约E9.5的PAR1缺陷胚胎。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 凝血酶信号在胚胎发育中的作用可能与 它在止血方面的作用，至少在通常意义上是这样。原位杂交 E9.5时显示PAR1在心内膜和血管内皮细胞中表达， 提示PAR1信号可能在正常血管中起重要作用 发育和血管完整性。首席调查员假定 凝固级联在一定程度上起到了监测 并调节发育中的血管的完整性。为了测试这些 假设他提出了以下具体目标。目标1将询问 问：在哪种细胞类型(S)中，PAR1信号对胚胎很重要 发展？为了解决这个问题，他们将：a)使用Lacz敲入 确定表达PAR1的细胞类型并确定它们在 PAR1缺陷胚胎；b)PAR1缺陷的血管发育特征 C)通过转基因挽救来确定是否缺乏PAR1功能 内皮细胞是PAR1缺陷胚胎的主要缺陷；d)使用 敲击功能增益突变以识别PAR1所在细胞 激活通常发生在胚胎发育期间；e)检验假设 不受抑制的凝血酶产生和PAR1信号转导 血栓调节蛋白缺陷胚胎的死亡。在《目标2》中，他们提出了这个问题： 除了PAR1，还有什么是凝血级联的其他效应器 胚胎发育？他们将：a)检验纤维蛋白原 在没有PAR1的情况下变得重要，b)确定PAR4和/或AS 然而，未知受体在胚胎中提供“备份”凝血酶信号 发展，c)确定PAR2缺乏的影响与 胚胎发育方面的其他缺陷。

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.