Plasmalogen-derived bioactive lipids in atherosclerosis

描述（由申请人提供）：动脉粥样硬化性血管疾病是工业化国家死亡和发病的主要原因。了解导致动脉粥样硬化的生化机制可能会导致新的治疗和预防措施。已证明髓过氧化物酶（MPO）和MPO衍生产物的水平在动脉粥样硬化组织中升高，并可能介导促动脉粥样硬化机制。在活化时，单核细胞和巨噬细胞释放MPO并产生其底物过氧化氢，导致MPO催化的反应性氯化物质（RCS）次氯酸的产生。我们已经发现RCS靶向缩醛磷脂的乙烯基醚键，导致1-氯脂肪醛（1-ClOFA D）的产生，并且已经表明1-ClOFA D水平在人动脉粥样硬化组织中增加了1400倍。我们发现，1-氯代脂肪酸D代谢为1-氯脂肪酸和1-氯脂肪醇，这沿着1-氯代脂肪酸D是一个新的氯化脂质体的主要成员。初步研究表明，1-氯脂肪酸：1）在活化的人单核细胞和人动脉粥样硬化组织中升高; 2）抑制内皮型一氧化氮合酶; 3）在巨噬细胞和平滑肌细胞中埃洛匹神经酰胺蓄积; 4）引起巨噬细胞凋亡; 5）刺激巨噬细胞产生促炎细胞因子; 6）存在于人血浆中。在这个建议中，我们将测试的假设，1-氯代维生素D代谢物是介导的动脉粥样硬化。这一假设将通过三个具体目标进行检验。具体目标1将检验1-氯代维生素D代谢物是动脉粥样硬化的候选介质和生物标志物的假设。将采用基于质谱的筛选来鉴定人单核细胞和巨噬细胞以及人动脉粥样硬化组织中的1-氯吡格雷D代谢物。将进行一项病例对照研究，以确定1-氯吡格雷D的代谢产物作为人类冠状动脉疾病的生物标志物。1-还将在来自LDL受体-/-小鼠的动脉粥样硬化组织和血浆中鉴定ClODN代谢物，所述LDL受体-/-小鼠在其巨噬细胞中过表达人MPO，所述LDL受体-/-小鼠食用致动脉粥样硬化饮食。具体目标2将检验1-氯吡格雷D代谢物介导促炎和促动脉粥样硬化机制的假设。氯化脂质介导的eNOS功能障碍的机制将进行检查。将检查1-ClOND代谢物作为促炎细胞因子释放介质的作用。目标2的一个子假设是氯化脂质代谢物增加神经酰胺的从头生物合成和随后的细胞凋亡。具体目标3将检验氯化脂质导致动脉粥样硬化的假设。将在喂食食物和补充有2-氯棕榈酸的促动脉粥样硬化饮食的apo E-/-和LDL受体-/-小鼠中检查动脉粥样硬化。将氯化脂质代谢物的血浆和尿液水平以及动脉粥样硬化水平与目标1研究中使用促动脉粥样硬化饮食的hMPO和MPO-/-小鼠的水平进行比较。总之，拟议的研究将使用多学科的方法来确定氯化脂质种类作为动脉粥样硬化的新介质。 公共卫生相关性：心血管疾病是工业化国家死亡和发病的主要原因。了解导致动脉粥样硬化的生化机制可能会导致新的治疗方法和新的生物标志物的发展。在这个建议中，我们将测试的假设，新的氯化脂质物种是动脉粥样硬化的重要介质。

DESCRIPTION (provided by applicant): Atherosclerotic vascular disease is the leading cause of death and morbidity in industrialized nations. Understanding the biochemical mechanisms leading to atherosclerosis may lead to new therapies and preventative measures. Levels of myeloperoxidase (MPO) and MPO-derived products have been shown to be elevated in atherosclerotic tissue and potentially mediate pro-atherosclerotic mechanisms. Upon activation, monocytes and macrophages release MPO and produce its substrate, hydrogen peroxide, resulting in MPO-catalyzed production of the reactive chlorinating species (RCS), hypochlorous acid. We have discovered that RCS target the vinyl ether bond of the plasmalogen phospholipids resulting in 1-chlorofatty aldehyde (1-ClFALD) production and have shown that 1-ClFALD levels are increased 1400-fold in human atherosclerotic tissue. We found that 1-ClFALD is metabolized to 1-chlorofatty acid and 1-chlorofatty alcohol, which along with 1-ClFALD are primary members of a novel chlorinated lipidome. Preliminary studies show that 1-chlorofatty acid: 1) is elevated in activated human monocytes and in human atherosclerotic tissue; 2) inhibits endothelial nitric oxide synthase; 3) elicits ceramide accumulation in macrophages and smooth muscle cells; 4) causes macrophage apoptosis; 5) stimulates the production of pro-inflammatory cytokines by macrophages and 6) is present in human plasma. In this proposal we will test the hypothesis that 1-ClFALD metabolites are mediators of atherosclerosis. This hypothesis will be tested by three specific aims. Specific Aim 1 will test the hypothesis that 1-ClFALD metabolites are candidate mediators and biomarkers of atherosclerosis. Mass spectrometry- based screens will be employed to identify 1-ClFALD metabolites in human monocytes and macrophages, as well as human atherosclerotic tissue. A case-control study will be performed to identify metabolites of 1- ClFALD as biomarkers of human coronary artery disease. 1-ClFALD metabolites will also be identified in atherosclerotic tissue and plasma from LDL receptor-/- mice on an atherogenic diet that overexpress human MPO in their macrophages. Specific Aim 2 will test the hypothesis that 1-ClFALD metabolites mediate pro-inflammatory and proatherogenic mechanisms. Mechanisms responsible for chlorinated lipid mediated eNOS dysfunction will be examined. The role of 1-ClFALD metabolites as mediators for the release of pro-inflamma- tory cytokines will be examined. A sub-hypothesis of Aim 2 is that chlorinated lipid metabolites increase de novo ceramide biosynthesis and subsequent apoptosis. Specific Aim 3 will test the hypothesis that chlorinated lipids cause atherosclerosis. Atherosclerosis will be examined in apo E-/- and LDL receptor-/- mice that are fed chow and pro-atherogenic diets that are supplemented with 2-chloropalmitic acid. Plasma and urine levels of chlorinated lipid metabolites, as well as the level of atherosclerosis, will be compared to those levels in both hMPO and MPO-/- mice on pro-atherogenic diets in studies from Aim 1. Taken together, the proposed studies will use a multi-disciplinary approach to identify chlorinated lipid species as novel mediators of atherosclerosis. PUBLIC HEALTH RELEVANCE: Cardiovascular disease is the leading cause of death and morbidity in industrialized nations. Understanding the biochemical mechanisms leading to atherosclerosis may lead to new therapies and the development of new biomarkers. In this proposal we will test the hypothesis that novel chlorinated lipid species are important mediators of atherosclerosis.