Intervention of Atherogenesis by Gene Transfer

o首席研究员/项目主任（最后一名，第一名，中间名）：Davis，Ro，qer A。说明：说明申请的广泛、长期目标和具体目标，并参考项目的健康相关性。简要描述研究设计和实现这些目标的方法。避免总结过去的成就和使用第一人称。本摘要旨在作为一个简洁和准确的描述拟议的工作时，从申请分开。如果申请获得资助，此描述将成为公共信息。因此，不包括专有/机密信息。不要超过提供的瓷砖空间。我们的假设始于枯否细胞吸收氧化LDL的步骤。由于枯否细胞表达载脂蛋白E和ATP盒脂质转运蛋白，我们提出枯否细胞摄取的致动脉粥样硬化脂质（即氧化磷脂和氧化固醇）可能随后分泌到肝窦中。肝窦内载脂蛋白E浓度相对较高，与载脂蛋白E结合形成脂蛋白可促进枯否细胞分泌致动脉粥样硬化脂质。致动脉粥样硬化脂质也可由枯否细胞通过ABCA 1与实质细胞合成的载脂蛋白A1联合分泌。产生的脂蛋白颗粒可以通过LDL受体、LDL受体样蛋白（LRP）或SR-B1受体被实质细胞清除。一旦被实质细胞吸收，我们提出氧化的致动脉粥样硬化脂质有三种命运：（1）排泄到胆汁中，（2）排泄到胆汁中，（3）作为从头合成的脂蛋白的组分分泌到血浆中。这些致动脉粥样硬化的氧化脂质被肝脏处理的方式部分地决定了有多少脂质可到达动脉壁并引发动脉粥样硬化。我们提出的研究将使用转基因小鼠和一种选择性替代在前一资助期开发的枯否细胞的方法来检验这一假设。除了获得脂质和脂蛋白代谢的新知识，我们的研究发现可能会提高我们通过基因转移干预动脉粥样硬化形成的潜在治疗效果。在下一个资助期内，我们将努力实现以下具体目标：具体目标1：确定肝脏（实质细胞和枯否细胞）在与氧化LDL相关的促动脉粥样硬化信号分子的产生和失活中的作用。具体目标二：目的：采用一种新的方法，选择性地用骨髓来源的细胞替代枯否细胞，以确定肝实质和枯否细胞从血浆中清除和代谢与氧化LDL相关的促动脉粥样硬化脂质的分子机制，以及这些过程影响动脉粥样硬化的发生。具体目标3：确定LDL受体-/-小鼠中CYP 7A 1的转基因表达阻断饮食诱导的高脂血症的机制及其如何影响动脉粥样硬化形成。性能现场=

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===========================================