Intervention of Atherogenesis by Gene Transfer

O首席调查员/计划主任(最后、第一、中间)：Davis，Ro，QER A描述：说明应用程序的广泛、长期目标和具体目标，并参考项目与健康的相关性。简明扼要地描述实现这些目标的研究设计和方法。避免总结过去的成就和使用第一人称。此摘要的目的是在脱离应用程序时，作为对拟议工作的简洁和准确的描述。如果申请得到资助，这一描述将成为公开信息。因此，不包括专有/机密信息。不要超过提供的瓷砖空间。我们的假设始于库普弗细胞摄取氧化低密度脂蛋白的那一步。由于Kupffer细胞表达载脂蛋白E和ATP盒脂质转运体，我们推测Kupffer细胞摄取的致动脉粥样硬化的脂质(即氧化的磷脂和氧化甾醇)可能随后被分泌到肝窦。Kupffer细胞可能通过形成与载脂蛋白E相关的脂蛋白来促进促动脉粥样硬化脂质的分泌，载脂蛋白E在肝窦内处于相对较高的浓度。促动脉粥样硬化脂质也可能由Kupffer细胞通过ABCA1与由实质细胞合成的apo A1结合而分泌。实质细胞可以通过低密度脂蛋白受体、低密度脂蛋白受体样蛋白(LRP)或SR-B1受体清除产生的脂蛋白颗粒。一旦被实质细胞摄取，我们提出氧化的致动脉粥样硬化脂类有三种命运：(1)排泄到胆汁中；(2)分解代谢；(3)作为从头合成的脂蛋白的组成部分分泌到血浆中。这些导致动脉粥样硬化的氧化脂质被肝脏处理的方式在一定程度上决定了有多少可以到达动脉壁并启动动脉粥样硬化。我们提议的研究将使用转基因小鼠和一种有选择地取代前一资金时期培育的Kupffer细胞的方法来检验这一假说。除了获得关于脂类和脂蛋白代谢的新知识外，我们的研究发现可能会增强我们通过基因转移干预动脉粥样硬化的潜在治疗效果。在下一个资金阶段，我们将努力实现以下具体目标：具体目标1：确定肝脏(实质细胞和库普弗细胞)在氧化低密度脂蛋白相关的致动脉粥样硬化信号分子的产生和失活中的作用。具体目的2：利用一种新的方法选择性地用骨髓来源的细胞替代Kupffer细胞，以确定肝实质细胞和Kupffer细胞从血浆中清除和代谢与氧化低密度脂蛋白相关的促动脉粥样硬化脂质的分子机制，这些过程影响动脉粥样硬化的形成。具体目的3：确定在低密度脂蛋白受体/低密度脂蛋白受体/低密度脂蛋白小鼠中转基因表达的细胞色素P7A1阻断饮食诱导的高脂血症的机制及其对动脉粥样硬化形成的影响。表演网站========================================Section End===========================================

o Principal Investigator/Program Director (Last, first, middle): Davis, Ro,qer A. DESCRIPTION: State the application's broad, long-term objectives and specific aims, making reference to the health relatedness of the project. Describe concisely the research design and methods for achieving these goals. Avoid summaries of past accomplishments and the use of the first person. This abstract is meant to serve as a succinct and accurate description of the proposed work when separated from the application. If the application is funded, this description, as is, will become public information. Therefore, do not include proprietary/confidential information. DO NOT EXCEED TIlE SPACE PROVIDED. Our hypothesis begins at the step in which Kupffer cells take up oxidized LDL. Since Kupffer cells express apo E and ATP cassette lipid transporters, we propose that proatherogenic lipids (i.e. oxidized phospholipids and oxysterols) taken up by Kupffer cells may be subsequently secreted into the hepatic sinusoids. The secretion of the proatherogenic lipids by Kupffer cells may be facilitated by forming lipoproteins in association with apo E which is in relatively high concentration within the hepatic sinusoids. The proatherogenic lipids may also be secreted by Kupffer cells via ABCA1 in association with apo A1, which is synthesized by the parenchymal cell. The resulting lipoprotein particles can be cleared by parenchymal cells via either the LDL receptor, the LDL receptor-like protein (LRP) or the SR-B1 receptor. Once taken up by parenchymal cells, we proposed there are three fates of the oxidized proatherogenic lipids: (1) excretion into bile, (2) catabolism and (3) secretion into plasma as a component of de novo synthesized lipoproteins. The manner in which these proatherogenic oxidized lipids are processed by the liver in part determines how much is available to reach the arterial wall and initiate atherogenesis. Our proposed studies will examine this hypothesis using transgenic mice and a method that selectively replaces Kupffer cells which were developed during the previous funding period. In addition to gaining new knowledge of lipid and lipoprotein metabolism, our research discoveries may enhance the potential therapeutic efficacy of our intervention of atherogenesis by gene transfer. During the next funding period, we will direct our efforts to achieving the following specific aims: Specific aim 1: to determine the role of the liver (parenchymal and Kupffer cells) in the production and inactivation of proatherogenic signaling molecules associated with oxidized LDL. Specific Aim 2: To use a novel method to selectively replace Kupffer cells with bone marrow derived cells in order to determine the molecular mechanisms through which liver parenchymal and Kupffer cells remove from plasma and metabolize proatherogenic lipids associated with oxidized LDL and these processes influence atherogenesis. Specific Aim 3: To determine the mechanism through which transgenic expression of CYP7A1 in LDL receptor -/- mice blocks diet-induced hyperlipidemia and how this affects atherogenesis. PERFORMANCE SITE ========================================Section End===========================================