PLATELET-ACTIVATING FACTOR IN THROMBOTIC PLATELET-LEUKOCYTE INTERACTIONS

血栓性血小板-白细胞相互作用中的血小板激活因子

基本信息

批准号：
7615046
负责人：
THOMAS MCINTYRE
金额：
$ 38.46万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/7615046
关键词：
Abbreviations Acetyltransferase Acute Adhesions Agonist Animal Model Antibodies Antiphospholipid Antibodies Aspirin Blood Platelets Cells Clinic Clinical Condition Coronary Disease Endotoxins Enzymes Event GTP-Binding Proteins Genetic Variation Human Immune system Individual Inflammatory Integrins Ischemia Knowledge Lead Lecithin Left Leukocytes Ligands Link Lipids Lipopolysaccharides Lipoproteins Localized Lysophosphatidylcholines Mediator of activation protein Myocardial Organ Pathway interactions Phospholipids Physiological reperfusion Placement Platelet Activating Factor Predisposition Process Production Prostaglandin Production Prostaglandin-Endoperoxide Synthase Proteins Rate Reaction Receptor Activation Reperfusion Injury Reperfusion Therapy Research Personnel Role Route Sepsis Signal Transduction Source Stents Surface System TLR4 gene Techniques Testing Thromboplastin Thrombosis Thromboxane A2 Thromboxane Production Thromboxanes Thrombus Time Tissues Translating Vasoconstrictor Agents cyclooxygenase 1 cyclooxygenase 2 cytokine design eicosanoid metabolism endotoxin receptor hemodynamics in vivo inhibitor/antagonist leukocyte activation lipid mediator lung injury novel platelet activating factor receptor programs receptor receptor function success synthetic enzyme

项目摘要

The phospholipid Platelet-activating factor (PAF) is perhaps the most powerful pro-inflammatory and prothromobtic lipid mediator yet defined. All cellular components of the acute inflammatory system express the single known receptor for PAF. PAF is synthesized by, and retained on the surface of, activated endothelial ceils where it stimulates tethered leukocytes. PAF accumulation normally is tightly controlled, but PAF has a role in thrombosis, sepsis and reperfusion damage. There are deficits in our knowledge of how, when, and where PAF receptor ligands are formed, how PAF is presented to cells of the innate immune system and how PAF stimulated cells interact with other cells. We do not know whether PAF receptor ligands are formed during stent placement, whether PAF stimulated leukocytes provide platelets with substrate for thromboxane production even when platelet cyclooxygenase has been inhibited by aspirin, and we do not know whether PAF production by leukocytes stimulated with endotoxin is mimicked by endogenous agonists that include anti-phospholipid antibodies. We propose to identify the pathways leading to activation of the rate-limiting PAF synthetic activity, determine whether individuals vary in their ability to make PAF, take advantage of new information and techniques to purify the enzyme responsible for PAF synthesis for eventual rational inhibitor design, and identify and modulate mechanisms that cause microparticle formation and PAF release, and to determine whether these parameters correlate with thrombosis. We will define the pro-thrombotic lipids released during stent placement, we will investigate alternate routes to generate thromboxane Aa, and determine whether this correlates with susceptibility to slow reflow after stent placement, and we will test alternate, endogenous ligands of TLR4 as leukocyte agonists. We have four aims: Aim 1. Mechanistically define adhesion-dependent PAF synthesis in PMN. Aim 2. Purify and molecularly characterize the leukocyte PAF acetyltransferase synthetic enzyme. Aim 3. Identify factors that extend the effect of PAF through microparticle release. Aim 4. Define novel routes to leukocyte activation and inflammatory mediator production

磷脂血小板激活因子（PAF）可能是最强大的促炎和促血栓形成因子脂质介质尚未定义。急性炎症系统的所有细胞成分都表达 PAF 的单一已知受体。 PAF 由活化的内皮细胞合成并保留在其表面它刺激束缚的白细胞。 PAF 的积累通常受到严格控制，但 PAF 具有在血栓形成、败血症和再灌注损伤中发挥作用。我们对 PAF 受体配体如何、何时、何地形成以及 PAF 是如何形成的了解还存在缺陷。呈现给先天免疫系统的细胞以及 PAF 刺激的细胞如何与其他细胞相互作用。我们不知道支架置入过程中PAF受体配体是否形成，PAF是否受到刺激即使血小板环氧合酶存在，白细胞也为血小板提供产生血栓素的底物已被阿司匹林抑制，我们不知道白细胞是否会刺激 PAF 的产生内毒素被包括抗磷脂抗体在内的内源性激动剂所模拟。我们建议确定导致限速 PAF 合成活性激活的途径，确定个体的 PAF 能力是否存在差异，利用新信息和纯化负责 PAF 合成的酶的技术，以最终设计合理的抑制剂，以及识别和调节导致微粒形成和 PAF 释放的机制，并确定这些参数是否与血栓形成相关。我们将定义期间释放的促血栓脂质支架置入后，我们将研究生成血栓素 Aa 的替代途径，并确定这是否与支架放置后缓慢回流的敏感性相关，我们将测试替代的内源性 TLR4 配体作为白细胞激动剂。我们有四个目标：目标 1. 从机制上定义 PMN 中粘附依赖性 PAF 合成。目标 2. 纯化白细胞 PAF 乙酰转移酶合成酶并对其进行分子表征。目标 3. 确定通过微粒释放延长 PAF 效果的因素。目标 4. 定义白细胞激活和炎症介质产生的新途径