一类新型LDL磷脂氧化产物在动脉粥样硬化中的作用机制研究

项目名称： 一类新型LDL磷脂氧化产物在动脉粥样硬化中的作用机制研究

项目编号： No.31470831

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物物理、生化与生物分子学、生物力学与组织工程

项目作者： 尹慧勇

作者单位： 中国科学院上海生命科学研究院

项目金额： 85万元

中文摘要： 动脉粥样硬化是心脑血管病的主要致病原因之一，是由血管壁中的多种细胞相互作用引起组织损伤、斑块形成的一种慢性疾病，炎症和氧化应激对其发生发展极其重要。巨噬细胞是动脉粥样硬化斑块的主要成分，具有高度的可塑性，小鼠斑块中主要检测到M1、M2、Mox 三种亚型。近年来许多的证据表明LDL磷脂氧化产物作用于巨噬细胞并影响动脉粥样硬化，相关机制尚待进一步阐明。利用质谱我们在体外和体内实验中鉴定了一类新型的磷脂氧化产物，我们合成了其中的一个代表化合物，它不仅可以诱导Mox，还可以通过激活PPAR和Nrf2，抑制NFκB的活性，参与炎症和氧化应激。因此我们认为这类磷脂氧化产物可能是影响动脉粥样硬化过程炎症和氧化应激的重要因子。在本项目中，我们将进一步利用生物化学、化学合成、现代质谱技术、组学手段、细胞和动物模型等，研究其对动脉粥样硬化的作用以及分子机制，该项目可能对动脉粥样硬化的预防和治疗提供新思路。

中文关键词： 磷脂；自由基；动脉粥样硬化；巨噬细胞；质谱

英文摘要： Cardiovascular diseases (CVDs) caused by atherosclerosis are among the leading causes for mortality and morbidity in industrialized countries while China,as a developing country, has even higher mortality rate of CVD than USA and Japan. The molecular mechanisms of atherosclerosis appear to be multifactual and remain to be clearly defined; mounting evidence suggests that chronic inflammatory and oxidative stress play an important role. Atherosclerotic lesion formation resulted from interactions among different cell types including macrophages, endothelial cells, smooth muscle cells, and platelets within the vessel wall. Recent studies have demonstrated that oxidized phospholipids on LDL have deep impact on atherosclerosis. Macrophages are one of the major cell types found in the atherosclerotic plaque and acculating data suggest that macrophges play a critical role in every stage of athersclerosis.The early lesion formation appears to be resulted from phagocytosis of oxidized LDL by macrophage. However, the exact components in oxidized LDL that may be responsible for mediating early lesion formation have not been clearly elucidated. We have identified a novel class of oxidized phospholipid in oxidized LDL in vitro and in human atherosclerotic plaques. These free radical oxidation products were termed deoxy-A2/J2-IsoP-PC due to the presence of a cyclopentenone moiety, the similar structural motif found in cyclooxygenase (COX)-derived prostaglandins, 15-deoxy-PGJ2 (15d-PGJ2). These electrophilic compounds are known to have profound biological activities by covalent modification of critical cystein residues in proteins through Michael addition or Schiff base formation with lysines. We chemically synthesized a representative compound 15d-PGJ2-PC for this novel class of oxidized phospholipids and our preliminary experiments showed that 15d-PGJ2-PC can active Nrf2 and PPARs including PPARα, PPARδ and PPARγ, while inhibition of NFκB, suggesting that 15d-PGJ2-PC may regulate inflammatory response and oxidative stress.Interestingly, these compounds can induce a new phenotype of polarized macrophage, Mox (induced by oxPAPC). Our lipidomic and metabolomic studies demonstrated that this novel Mox phenotype had distinct metabolic features from M1 and M2 phenotypes including arachidonic acid pathways and glycolysis. Based on these preliminary data, we hypothesize that these novel phospholipid oxidation products may modulate atherosclerotic process by interacting with macrophages in response to inflammation and oxidative stress. In this project, we will utilize biochemistry, synthetic chemistry, lipidomics, metabolomics, and Click chemistry-based proteomics to study the roles of deoxy-A2/J2-PC in macrophages and atherosclerosis animal model. We contend that successful completion of this project may shed light into the novel molecular mechanisms of atherosclerosis and provide a potential therapeutic strategy for the prevention and treatment of atherosclerosis.

英文关键词： Phospholipids;Free Radical;Atherosclerosis;Macrophage;Mass Spectrometry