Oxidized Phospholipid-Induced Inflammation in Atherosclerosis

动脉粥样硬化中氧化磷脂诱发的炎症

• 批准号: 7082696
• 负责人: NORBERT LEITINGER
• 金额: $ 34.14万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7082696
• 关键词: atherosclerosis; binding proteins; biological signal transduction; cell adhesion; chemical structure function; chemokine; gene expression; genetically modified animals; inflammation; laboratory mouse; lipid structure; lipoxygenase; monocyte; oxidized lipid; phospholipids; polymerase chain reaction; protein structure function; toll like receptor; vascular endothelium

DESCRIPTION (provided by applicant): Atherosclerosis is a chronic inflammatory disease, characterized by specific infiltration of monocytic cells, such as monocytes and T-cells, while neutrophils are essentially absent in the fatty streak lesion. One of the earliest steps in the development of the atherosclerotic lesion is the adhesion of monocytes to endothelial cells of the vessel wall. Previously it was demonstrated that, if stimulated with minimally modified LDL (MM-LDL), endothelial cells are activated to specifically bind monocytes, but not neutrophils. This specificity towards mononuclear cells was subsequently observed with the activation of endothelial cells by oxidized 1-palmitoyl-2-arachidonoyl-s/7-glycero-3-phosphocholine (OxPAPC), implying lipid oxidation products as culprits in chronic inflammation. We hypothesize that specific phospholipid oxidation products (OxPL) trigger vascular inflammation and determine monocyte specificity characteristic of atherosclerosis and other chronic inflammatory diseases. The outcome of the proposed studies will add to our understanding of how atherosclerosis is initiated and propagated and should lead to new strategies in the treatment of chronic inflammatory disorders. The specific aims addressed in this proposal are: Specific Aim #1: To structurally identify individual OxPL that determine monocyte specific inflammation and to investigate the hypothesis that OxPL-induced signaling involves TLR4. We will investigate intracellular signaling pathways induced by OxPL that lead to specific monocyte adhesion in vitro, using HUVEC as well as isolated murine aortic EC. Furthermore, we will test the hypothesis that POVPC is one active component in OxPAPC that determines monocyte specificity and determine structure-function relationships. We will examine the role of TLR-4 and the involvement of the TLR-4 adaptor proteins MyD88 and TRIP, as well as respective downstream elements in OxPL-mediated signalling events. Specific Aim #2: To explore the hypothesis that OxPL are triggers of vascular inflammation in vivo. To mimic accumulation of OxPL in the vascular wall, we will topically apply OxPL to carotid arteries in mice and measure chemokine and adhesion molecule expression. Furthermore, we will use ex vivo perfused carotid arteries to study OxPL-induced monocyte rolling and adhesion. Specific Aim #3: To examine the hypothesis that OxPL-induced specific mononuclear cell accumulation in vivo requires a specific chemokine expression pattern and involves 12 lipoxygenase. Using the mouse air pouch model, we will examine OxPL-induced leukocyte accumulation in vivo and characterize leukocyte subsets. We will investigate the chemokine expression pattern as well as time course of expression in OxPL-induced compared to LPS-induced inflammation. Furthermore, we will investigate the role of 12-LO in OxPL-induced inflammation in vivo.

描述（由申请人提供）：动脉粥样硬化是一种慢性炎症性疾病，其特征是单核细胞（例如单核细胞和T细胞）的特异性浸润，而中性粒细胞在脂肪条纹病变中基本上不存在。动脉粥样硬化病变发展的最早步骤之一是单核细胞粘附在血管壁的内皮细胞上。以前证明，如果用最小修饰的LDL（MM-LDL）刺激内皮细胞会被激活以特异性结合单核细胞，而不是中性粒细胞。随后，通过氧化1-甲米酰基-2-芳二烯酰基-S/7-甘油-3-磷酸胆碱（OXPAPC）氧化的内皮细胞激活观察到对单核细胞的这种特异性，造成脂质氧化产物作为慢性炎症中的损伤。我们假设特定的磷脂氧化产物（OXPL）会引发血管炎症，并确定动脉粥样硬化和其他慢性炎症性疾病的单核细胞特异性特征。拟议研究的结果将增加我们对如何开始和传播动脉粥样硬化的理解，并应导致治疗慢性炎性疾病的新策略。本提案中针对的具体目的是： 特定目的1：在结构上识别确定单核细胞特异性炎症的单个OXPL，并研究了OXPL诱导的信号传导涉及TLR4的假设。我们将使用HUVEC以及分离的鼠主动脉EC研究由OXPL诱导的细胞内信号传导途径，从而导致特定的单核细胞粘附。此外，我们将检验以下假设：POVPC是OXPAPC中一个活跃成分，它决定了单核细胞特异性并确定结构 - 功能关系。我们将研究TLR-4的作用以及TLR-4衔接蛋白MYD88和TRIP的参与，以及OXPL介导的信号事件中各自的下游元素。 具体目的＃2：探讨牛的触发器是体内血管炎症的触发因素的假设。为了模仿OXPL在血管壁中的积累，我们将局部应用OXPL在小鼠的颈动脉上，并测量趋化因子和粘附分子表达。此外，我们将使用离体灌注颈动脉来研究OXPL诱导的单核细胞滚动和粘附。 特定目的＃3：要检验以下假设：OXPL诱导的特异性单核细胞在体内需要特定的趋化因子表达模式，并且涉及12脂氧酶。使用小鼠气袋模型，我们将检查体内OXPL诱导的白细胞积累，并表征白细胞子集。与LPS诱导的炎症相比，我们将研究OXPL诱导的趋化因子表达模式以及表达的时间过程。此外，我们将研究12-LO在OXPL诱导的体内炎症中的作用。