Role of Endothelial and Macrophage ApoER2 in Atherosclerosis Modulation

内皮细胞和巨噬细胞 ApoER2 在动脉粥样硬化调节中的作用

• 批准号: 8635794
• 负责人: David Yiu-Kwan Hui
• 金额: $ 71.39万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8635794
• 关键词: Acceleration; Acute myocardial infarction; Adaptor Signaling Protein; Address; Adhesions; Adhesives; Apolipoprotein E; Apoptosis; Apoptotic; Arterial Fatty Streak; Atherosclerosis; Attenuated; Behavior; Biochemical; Biology; Blood Vessels; Bone Marrow; Bone Marrow Cells; Cardiovascular Diseases; Cardiovascular system; Cell Culture Techniques; Cell Death; Cell physiology; Cells; Clinical; Coronary Arteriosclerosis; Cytoplasmic Tail; Development; Disease; Dominant-Negative Mutation; Endothelial Cells; Endothelium; Functional disorder; Gene Expression; General Population; Genes; Genetic Polymorphism; Goals; Health; Human; Individual; Injury; Knock-in Mouse; Knockout Mice; LDL-Receptor Related Protein 1; Laboratories; Lesion; Leukocytes; Ligands; Link; Lipids; Lipoprotein Receptor; Lipoproteins; Low Density Lipoprotein Receptor; Mediating; Metabolism; Modification; Molecular; Mus; Myelogenous; Myocardial Infarction; Necrosis; Nitric Oxide Synthase; Peroxisome Proliferator-Activated Receptors; Phenotype; Phosphorylation; Phosphotransferases; Plasma; Process; Property; Proteins; Regulation; Research; Research Proposals; Role; Scanning; Signal Transduction; Testing; Variant; Work; apolipoprotein E receptor 2; apolipoprotein E-3; atherogenesis; base; cell behavior; cell motility; cell type; combat; gain of function; genome wide association study; genome-wide linkage; human NOS3 protein; improved; in vivo; intravital microscopy; macrophage; monocyte; monolayer; mutant; novel; offspring; premature; premature atherosclerosis; prevent; programs; public health relevance; receptor; reconstitution; research study; treatment strategy

PROJECT SUMMARY/ABSTRACT: Genome-wide association analyses have linked variants of the LRP8 gene, including the R952Q LRP8 variant, with premature atherosclerosis and acute myocardial infarction in humans, indicating that its encoded protein apoE receptor-2 (apoER2) has a major impact on cardiovascular health and disease. How apoER2 influences cardiovascular biology is entirely unknown. We recently discovered that apoER2 deletion in LDL receptor-null mice causes marked acceleration of atherogenesis and promotes lesion necrosis without influencing plasma lipoprotein metabolism. The overall goal of this multiple-PI project is to determine how apoER2 in endothelium and macrophages contributes to cardiovascular protection. This will be accomplished by two currently collaborating laboratories with complementary expertise in the study of lipoproteins, lipoprotein receptors and vascular biology. Our recent cell culture work has revealed that through apoER2, apolipoprotein E3 (apoE3) activates endothelial NO synthase (eNOS) and thereby promotes endothelial cell migration, and also blunts endothelial cell-monocyte adhesion. In contrast, apoER2-R952Q has dominant-negative effect on eNOS activation by wild-type receptor. It has further been found that Lrp8-/- mice have impaired reendothelialization. In Aim 1, an apoER2 cytoplasmic domain mutant incapable of adaptor protein interaction and candidate adaptor protein knockdown will be employed to determine the biochemical basis for apoER2 action in endothelium. The underpinnings of apoER2-R952Q dysfunction will also be discerned, and the rescue of cardioprotective behaviors by apoER2-R952Q- expressing endothelial cells will be attempted with NO donor. Using a recently-created floxed Lrp8 mouse, endothelial apoER2 regulation of endothelial cell-leukocyte adhesion will also be studied in vivo by intravital microscopy. Preliminary work has additionally shown that in macrophages apoER2 deficiency causes exaggerated oxLDL-induced neutral lipid accumulation and cell death/apoptosis. Lack of apoER2 in macrophages also results in increases in PPAR¿ and PPAR¿-responsive gene expression. With a focus on PPAR¿-mediated processes, in Aim 2 the mechanism(s) by which apoER2 modulates intracellular signaling in macrophages and thereby governs their function and fate will be discerned. In Aim 3, studies will be done using the Lrp8 floxed mouse or bone marrow reconstitution on LDL receptor-null background to determine the contributions of endothelial versus macrophage apoER2 to protection from atherosclerosis progression and plaque necrosis. The planned studies will provide critical new understanding of the basis by which apoER2 and its major ligand apoE influence cardiovascular health. The new information gained promises to improve as well as personalize therapies to combat cardiovascular disease in a large number of individuals with LRP8 variants (~1%) and/or apoE polymorphisms (~15%). The general population may also benefit by the development of novel therapies that harness these processes to optimize cardiovascular protection.

项目摘要/摘要： 全基因组关联分析已将 LRP8 基因关联起来，包括 R952Q LRP8 变体，导致人类过早动脉粥样硬化和急性心肌梗塞，表明其 编码蛋白 apoE 受体 2 (apoER2) 对心血管健康和疾病有重大影响。 apoER2 对心血管生物学的影响尚不清楚。我们最近发现 apoER2。 LDL受体缺失小鼠中的缺失会导致动脉粥样硬化明显加速并促进病变 坏死而不影响血浆脂蛋白代谢 该多 PI 项目的总体目标是 确定内皮细胞和巨噬细胞中的 apoER2 如何有助于心血管保护。 由两个目前在研究方面具有互补专业知识的合作实验室来完成 我们最近的细胞培养工作揭示了脂蛋白、脂蛋白受体和血管生物学。 通过apoER2，载脂蛋白E3（apoE3）激活内皮NO合酶（eNOS），从而 促进内皮细胞迁移，并减弱内皮细胞-单核细胞粘附。 apoER2-R952Q 对野生型受体的 eNOS 激活具有显性负效应。 发现 Lrp8-/- 小鼠的 Aim 1（apoER2 胞质结构域突变体）的再内皮化受损。 无法与衔接蛋白相互作用，并且候选衔接蛋白敲低将被用于 确定 apoER2 在内皮细胞中作用的生化基础 apoER2-R952Q 的基础。 功能障碍也将被识别，并且 apoER2-R952Q- 可以挽救心脏保护行为 将使用最近创建的 floxed Lrp8 小鼠尝试表达内皮细胞。 内皮apoER2对内皮细胞-白细胞粘附的调节也将通过intravital进行体内研究 显微镜检查还表明，apoER2 缺陷会导致巨噬细胞。 oxLDL 诱导的中性脂质积累和细胞死亡/凋亡过度。 巨噬细胞也会导致 PPAR 增加¿和 PPAR?? - 响应性基因表达。 PPAR?? -介导的过程，目标 2 中 apoER2 调节细胞内信号传导的机制 在目标 3 中，将进行研究。 使用 Lrp8 floxed 小鼠或在 LDL 受体无效背景下进行骨髓重建来确定 内皮细胞与巨噬细胞 apoER2 对防止动脉粥样硬化进展的贡献 计划中的研究将为基础提供重要的新认识。 apoER2 及其主要配体 apoE 影响心血管健康。 改进并个性化治疗方法以对抗大量个体的心血管疾病 具有 LRP8 变异 (~1%) 和/或 apoE 多态性 (~15%) 的普通人群也可能受益。 开发利用这些过程来优化心血管保护的新疗法。