ROLE OF MACROPHAGE MEMBRANE RECEPTORS IN ATHEROGENESIS

巨噬细胞膜受体在动脉粥样硬化形成中的作用

• 批准号: 7551457
• 负责人: OSWALD QUEHENBERGER
• 金额: $ 33.32万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7551457
• 关键词: CD antigens; atherosclerotic plaque; cell adhesion molecules; cytokine receptors; gene targeting; human tissue; hypercholesterolemia; immunogenetics; laboratory mouse; lipoxygenase; low density lipoprotein; macrophage; molecular pathology; monocyte chemoattractant protein 1; oxidized lipid; protein binding; receptor binding

DESCRIPTION (provided by the applicant): The long term goal of the studies proposed is to improve our understanding at the molecular level of the membrane receptors involved in recruitment of circulating monocytes to the developing atherosclerotic lesion and the conversion of those monocytes to foam cells. Emphasis will be placed on MCP-1 and its receptor, CCR2, because the central role of this chemokine pair early lesion formation has been clearly established by gene targeting experiments. We have previously demonstrated that CCR2 expression in monocytes is reduced by ligands for the nuclear receptor PPAR. We propose intensive studies of this and other methods of regulating the expression of CCR2 and also the regulation of other chemokine receptors and adhesion molecules, including CX3CR1, CDlla, CD1lb and CD49d. We have recently developed a novel approach to quantifying the recruitment of monocytes to the arterial wall in vivo in mouse models of atherosclerosis. This will be applied to studying the role of MCP-1 and CCR2 quantitatively by comparing wild-type mice with mice deficient in CCR2 or MCP-1. Using this new method we will also test the hypothesis that monocyte recruitment into developing lesions is preceded by a build-up of oxidized LDL in the sub-endothelial space. Another approach to this question will make use of mice deficient in 12/15-lipoxygenase, an enzyme believed to be involved in LDL oxidation. The role of CCR2 and of adhesion molecules will be studied clinically to determine whether regulation in humans parallels that previously described in mice. In these studies we will also test the reversibility of the effects of hypercholesterolemia on monocyte gene expression. Finally we will study the structure and function of receptors involved in the binding of oxidized LDL and of apoptotic cells, with emphasis on CD36 and CD68. We have shown that CD36 can bind either the lipid moiety of oxidized LDL or its isolated apoprotein B. Whether the binding occurs at the same sites or different sites remains to be determined. This will be approached by site-directed mutagenesis and by the preparation of chimeric receptors. Additionally, we will explore some apparent anomalies with regard to the ability of CD36 to internalize and cause degradation of oxidized LDL. Recently Dr. J. Aldon Lusis at UCLA, has succeeded in partially knocking out the gene for CD68. In collaboration with Dr. Lusis, we propose to test further the possible role of CD68 in the recognition and uptake of oxidized LDL and apoptotic cells. Finally, in collaboration with Dr. Jonathan Tait at the University of Washington, we will evaluate the ligand-binding properties of recombinant CD68 made in E. coli and therefore deficient in glycosyl post-translational additions.

描述（由申请人提供）： 拟议研究的长期目标是提高我们对 参与募集的膜受体的分子水平 循环单核细胞向发展中的动脉粥样硬化病变和 单核细胞转化为泡沫细胞。重点将放在MCP-1上 和它的受体CCR 2，因为这种趋化因子对的核心作用， 通过基因靶向实验已经清楚地确定了损伤的形成。 我们先前已经证明，单核细胞中CCR 2的表达减少， 核受体过氧化物酶体增殖物激活受体的配体。我们建议深入研究 这种和其他调节CCR 2表达的方法， 调节其他趋化因子受体和粘附分子，包括 CX 3CR 1、CD 11 a、CD 11b和CD 49 d。我们最近开发了一种新方法 本发明涉及在体内定量单核细胞向动脉壁的募集， 小鼠动脉粥样硬化模型。这将被应用于研究的作用， 通过比较野生型小鼠和缺陷型小鼠定量检测MCP-1和CCR 2 在CCR 2或MCP-1中。使用这种新方法，我们还将测试假设， 单核细胞募集到发展中的病变之前， 内皮下间隙中的氧化LDL。这个问题的另一种方法 将利用缺乏12/15-脂氧合酶的小鼠，这种酶被认为 参与LDL氧化。CCR 2和粘附分子的作用将 进行临床研究，以确定人类的调节是否与 以前在老鼠身上描述过。在这些研究中，我们还将测试 高胆固醇血症对单核细胞基因影响的可逆性 表情最后我们将研究受体的结构和功能 参与氧化LDL和凋亡细胞的结合，重点是 在CD 36和CD 68上。我们已经表明，CD 36可以结合的脂质部分， 氧化的LDL或其分离的载脂蛋白B。绑定是否发生在 同一地点或不同地点仍有待确定。这将是 通过定点诱变和通过制备嵌合体 受体。此外，我们将探讨一些明显的异常， 与CD 36内化并导致氧化LDL降解的能力有关。 最近加州大学洛杉矶分校的J·奥尔登·卢西斯博士成功地部分敲除了 CD 68的基因与卢西斯博士合作，我们建议测试 进一步研究了CD 68在识别和摄取氧化的 LDL和凋亡细胞。最后，与乔纳森·泰特博士合作， 华盛顿大学，我们将评估配体结合特性 在E.因此缺乏糖基翻译后 的增订条文