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: 8794465
• 负责人: David Yiu-Kwan Hui
• 金额: $ 68.81万
• 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/8794465
• 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; cardiovascular health; 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; personalized medicine; premature; premature atherosclerosis; prevent; programs; receptor; reconstitution; research study; treatment strategy

DESCRIPTION (provided by applicant): 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.

描述（由适用提供）：全基因组关联分析已连接LRP8基因的变体，包括R952Q LRP8变体，具有早产性动脉粥样硬化和人类的急性心肌梗死，表明其编码的蛋白质APOE Hotefor-2（APOEER2）对Cardiov蛋白质APOE Hofferor-2（APOEER2）具有重大影响。 APOER2如何影响心血管生物学是完全未知的。我们最近发现，LDL受体无效小鼠中的ApoER2缺失会引起动脉粥样硬化的加速并促进病变坏死而不会影响血浆脂蛋白代谢。这个多PI项目的总体目标是确定hatoer2在山上和巨噬细胞中如何贡献心血管保护。这将由两个目前与脂蛋白，脂蛋白受体和血管生物学研究的完整专业知识的目前合作实验室完成。我们最近的细胞培养工作表明，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，并钝化内皮细胞单细胞单细胞粘合剂。相反，Apoer2-R952Q对野生型受体的eNOS激活具有显着的阴性作用。进一步发现，LRP8 - / - 小鼠会损害再穿内皮化。在AIM 1中，将采用ApoER2细胞质结构域突变体无能力的衔接蛋白相互作用和候选衔接蛋白敲低的抑制作用来确定内皮中apoer2作用的生化基础。 APOER2-R952Q功能障碍的基础也将被辨别，并且将尝试使用ApoER2-R952Q-表达内皮细胞来拯救心脏保护行为，而没有供体。使用最近创建的FLOX LRP8小鼠，内皮apoer2调节内皮细胞 - 白细胞粘附的调节也将通过浸润显微镜在体内进行研究。初步工作还表明，在巨噬细胞中，apoer2缺乏会导致夸张的OXLDL诱导的中性脂质积累和细胞死亡/凋亡。巨噬细胞中缺乏apoer2还会导致PPARC和PPAR响应基因表达的增加。在AIM 2中，侧重于PPAR®介导的过程，APOER2通过该机制调节巨噬细胞中的细胞内信号传导，从而控制其功能和命运。在AIM 3中，将使用LRP8 Floxed小鼠或LDL受体无效背景上的骨髓重建进行研究，以确定内皮与巨噬细胞apoer2对保护动脉粥样硬化进展和斑块坏死的贡献。计划的研究将为ApoER2及其主要配体APOE影响心血管健康的基础提供关键的新理解。获得的新信息有望改善和个性化疗法，以打击许多LRP8变体（〜1％）和/或APOE多态性（〜15％）的个体中的心血管疾病。普通人群也可能受益于利用这些过程来优化心血管保护的新型疗法的发展。