RAGE and Mechanisms of Vascular Dysfunction

描述(由申请人提供)： 在这个程序的最后一个周期中，纯合子的RAGE零小鼠构成了发现的核心。我们证明RAGE在载脂蛋白E基因缺失小鼠的动脉粥样硬化中起关键作用，在缺氧时介导促炎基因和组织破坏性基因的上调，并在缺血/再灌流时介导心脏功能的丧失(L/R)。许多新的发现塑造了我们计划的方向：首先，我们发现RAGE细胞质结构域与Diaphanous-1(MDIA-1)相互作用，Diaphanous-1(MDIA-1)是Forin同源结构域蛋白家族的成员，也是RhoGTP酶的效应器。MDIA-1是RAGE配体介导的细胞迁移和激活CDC42/RAC-1所必需的。新的发现将mDial与平滑肌细胞、巨噬细胞和心肌细胞信号的关键特性联系起来。其次，项目2发现了一个意想不到的发现，RAGE在急性和慢性缺氧/缺血中对内皮细胞和单核/巨噬细胞中Egr-1的调节起着相反的作用。第三，项目1发现RAGE下调Abcg1和胆固醇向高密度脂蛋白的流出。第四，项目3发现，在L/R中，删除MDIAL在内心是高度保护的。作为一个项目，我们不仅通过我们的核心单位分享了工具和策略，更重要的是，我们试图了解愤怒信号的“大图景”。随着我们数据的展开，我们认识到RAGE信号并不是“一刀切的”，因为新的发现揭示了受体根据细胞类型、应激持续时间和特定形式的细胞应激而调节的不同路径。挑战在于如何将它们整合在一起。为此，我们已经产生了新的RAGE-和mDial FLOLLED来探测这个轴在动脉粥样硬化(项目1)、血管生成(项目2)和心肌梗死(项目3)中的细胞特异性信号。综上所述，这些发现构成了一组极具创新性和重要意义的问题的基础，这些问题测试了糖尿病和非糖尿病心血管病变中血管功能障碍的RAGE和mDial信号。使用新的和最先进的技术，小鼠和分子方法进行基因调控，我们处于有利地位，在这个计划的下一个周期领导RAGE的研究。

DESCRIPTION (provided by applicant): The homozygous RAGE null mouse formed the centerpiece of discoveries during the last cycle of this Program. We demonstrated that RAGE plays critical roles in atheroscierosis in apoE null mice, mediates upregulation of pro-inflammatory and tissue-destructive genes in hypoxia, and mediates loss of cardiac function in the heart upon ischemia/reperfusion (l/R). Multiple novel findings shape the direction of our Program: first, we discovered that the RAGE cytoplasmic domain interacts with diaphanous-1 (mDia-1), a member of the formin homology domain protein family and an effector of RhoGTPases. mDia-1 is essential for RAGE ligand-mediated cellular migration and activation of cdc42/rac-1. New discoveries link mDial to key properties of smooth muscle cells, macrophages and cardiomyocyte signaling. Second, Project 2 has discovered the unanticipated finding that RAGE plays opposing roles in acute vs. chronic hypoxia/ischemia on regulation of Egr-1 in endothelial cells and monocytes/macrophages. Third, Project 1 has discovered that RAGE downregulates ABCG1 and cholesterol efflux to HDL. Fourth, Project 3 has discovered that deletion of mDial is highly protective in the heart in l/R. As a Program, we have shared not merely tools and strategies by virtue of our Core units but, more importantly, we have sought to understand the "big picture" of RAGE signaling. As our data unfold, we recognize that RAGE signaling is not "one size fits all," as new discoveries have uncovered distinct pathways of regulation by the receptor depending on cell type, duration of stress, and specific form of cellular stress. The challenge is to put it together. Toward this end, we have generated novel RAGE- and mDial floxed to probe cell-specific signaling of this axis in atherosclerosis (Project 1), angiogenesis (Project 2) and myocardial infarction (Project 3). Taken together, these discoveries form the basis of a highly innovative and significant set of questions testing RAGE and mDial signaling in vascular dysfunction in diabetic- and non-diabetic cardiovascular pathology. Using novel and state-of-the-art techniques, floxed mice and molecular approaches to gene regulation, we are well-positioned to lead the study of RAGE in the next cycle of this Program.