Regulation of Endothelial Cell Inflammatory Responses

内皮细胞炎症反应的调节

• 批准号: 6758072
• 负责人: Judith Anne Berliner
• 金额: $ 29.73万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6758072
• 关键词: G protein; atherosclerosis; atherosclerotic plaque; bacterial disease; biological signal transduction; blood lipoprotein transport; cell cell interaction; clinical research; genetic transcription; human tissue; immunocytochemistry; inflammation; interleukin 8; laboratory mouse; lipid metabolism; monocyte; monocyte chemoattractant protein 1; morphology; neutrophil; oxidized lipid; phospholipids; receptor; receptor coupling; tissue /cell culture; transfection; vascular endothelium

The goal of these studies is to determine the importance of specific phospholipid oxidation products, 1- palmitoyl-2-epoxyisoprostane-sn-glycero-3-phosphorylcholine (PEIPC) and 1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphorylcholine (POVPC) as regulators of endothelial cell inflammatory responses. These phospholipids have been shown to increase monocyte-endothelial and inhibit neutrophil-endothelial interactions by non-classical signal transduction pathways. The in vivo importance of these phospholipids is suggested by their accumulation in atherosclerotic lesions and at other sites of chronic inflammation. We have identified candidate signal transduction pathways by which these bioactive lipids alter endothelial cell function and have obtained evidence for the involvement of more than one receptor in their effects on transcription of IL-8 and MCP-1 and monocyte binding. A major goal of this proposal is to complete identification of these receptors and signal transduction pathways. In Aim 1 we will test the hypothesis that PEIPC binds to a receptor complex, composed of a GPI anchored protein and a modified form of Toll 4, which alters caveolar function. These caveolar changes are hypothesized to result in activation of Src and/or SREBP. As a result LEF and/or SREBP are translocated into the nucleus resulting in activation of IL-8 transcription. We have identified cAMP and its downstream effector R-Ras as important signals activating endothelial cells to bind monocytes. In Aim 2 we will express both known and orphan lipid-binding G-protein coupled receptors to identify the PEIPC receptor mediating monocyte binding. The identified receptors will be overexpressed in mouse aorta, using adenovirai transfection, and their effect on fatty streak formation determined. We will also determine, using quantitative morphology and immunohistochemistry, if the proposed signal transduction pathways are altered in atherosclerosis. In Aim 3 we will test the hypothesis that the accumulation of phosholipid oxidiation products at sites of inflammation blocks neutrophil entry. For these studies we will use cell culture and also a mouse model involving bacterial endopthalmitis. To test the role of oxidized phospholipid accumulation, we will over and underexpress PON-2, an enzyme that hydrolyzes these oxidized phospholipids. The proposed studies will determine the importance of POVPC and PEIPC as mediators of atherosclerosis and other chronic inflammatory processes.

这些研究的目的是确定特定的磷脂氧化产物的重要性，1-棕榈酰-2-2-氧化甲氧基二异丙烷-SN-甘油-3-磷酸胆碱（PEIPC）和1-甲氧酰基-2-氧化酚-2-氧化剂-SN-SN-SN-SN-GLYCERO-3-磷酸磷酸llosine-3-磷酸llocholinellocholinellocholinellocholinellocholinellocholinellocholinellocholinoine- （POVPC）作为内皮细胞炎症反应的调节剂。这些磷脂已被证明会增加单核细胞 - 内皮细胞，并通过非经典信号转导途径抑制中性粒细胞 - 内皮相互作用。这些磷脂在体内的重要性是由于它们在动脉粥样硬化病变中和其他慢性炎症部位的积累而表明。我们已经确定了这些生物活性脂质改变内皮细胞功能的候选信号转导途径，并获得了涉及多个受体对IL-8和MCP-1和单核细胞结合的影响的证据。该建议的主要目标是完成这些受体和信号转导途径的识别。在AIM 1中，我们将测试PEIPC与受体复合物结合的假设，该假设由GPI锚定蛋白和Toll 4的改良形式组成，从而改变Caveolar功能。假设这些洞穴变化会导致SRC和/或激活 SREBP。结果，LEF和/或SREBP被易位到核中，导致IL-8转录激活。我们已经确定了CAMP及其下游效应R-RAS作为重要信号激活内皮细胞以结合单核细胞。在AIM 2中，我们将表达已知和孤儿脂质结合的G蛋白偶联受体，以鉴定PEIPC受体介导的单核细胞结合。鉴定的受体将使用adenovirai转染及其对确定脂肪条纹形成的影响在小鼠主动脉中过表达。如果提出的信号转导途径在动脉粥样硬化中发生改变，我们还将使用定量形态和免疫组织化学确定。在AIM 3中，我们将检验假设 在炎症部位积累的磷脂氧化产物会阻止中性粒细胞的进入。对于这些研究，我们将使用细胞培养物以及涉及细菌内腹膜的小鼠模型。为了测试氧化的磷脂积累的作用，我们将过时并脱离pon-2，这是一种水解这些氧化磷脂的酶。拟议的研究将确定POVPC和PEIPC作为动脉粥样硬化和其他慢性炎症过程的介体的重要性。