Isoeicosanoids& Biologically Active Oxidized Phospholipi

脂质过氧化是一个自然发生的过程，在一定程度上保护细胞和细胞大分子免受活性氧的伤害。现在人们普遍认识到，脂质过氧化也会导致生物活性产物，介导细胞对自由基过程的反应。此外，在脂质过氧化过程中会形成活性化学实体，这些实体具有足够的亲电性，可以共价修饰蛋白质和其他生物聚合物。这项拟议研究的总体目标是探索在细胞膜中以磷脂酯形式存在的多不饱和脂肪酸在自由基氧化过程中发生的初始化学事件。个别研究的一个主要焦点将集中在花生四烯酸的氧化，作为过氧化事件的一个特别敏感的目标。质谱学将作为表征氧化磷脂结构的主要工具。将对亲电脂类自由基产物和目标蛋白的共价加合物进行结构研究，以确定加合物的形成位置和开发出确定共价加合物脂类部分结构的技术。将开发第二个主要焦点来确定共价加合物的脂部分的结构。第二个主要焦点将是测试白三烯A4的替代途径。磷脂氧化的生物活性磷脂产物的结构表征将是一个合作项目的重点，以表征那些可能诱导抗炎巨噬细胞表型的氧化磷脂产物。第二项合作研究将涉及刺激内皮细胞环氧合酶基因诱导的氧化磷脂产物的特征。最后，将研究一种收集人体呼气气雾剂中存在的脂质过氧化产物的方法。这种新的、非侵入性的方法将被用来评估肺中的脂质过氧化事件，可以通过使用质谱学技术测量标记物来定量。将使用收集呼气中的非挥发性分子和定量测定花生四烯酸过氧化特定产物的技术，对患有上呼吸道、下呼吸道和肺泡肺疾病的受试者进行研究。

Lipid peroxidation is a naturally occurring process that in part, protects cells and cellular macromolecules from reactive oxygen species. It is now becoming widely appreciated that lipid peroxidation also leads to biologically active products that mediate cellular response to free radical processes. Also, reactive chemical entities are formed during lipid peroxidation that are sufficiently electrophilic to covalently modify proteins and other biopolymers. The overall goal of the proposed research is to explore the initial chemical event taking place during the free radical oxidation of polyunsaturated fatty acids present as phospholipid esters in the membranes of cells. A major focus of the individual studies will center around the oxidation of arachidonic acid as a particularly susceptible target for peroxidative events. Mass spectrometry will be used as the primary tool for structural characterization of oxidized phospholipids. Structural studies of covalent adducts of electrophilic lipid free radical products and target proteins will be carried to determine the site of adduct formation and techniques developed to determine the structure of the lipid portion of the covalent adduct. A second major focus will be developed to determine the structure of the lipid portion of the covalent adduct. A second major focus will be testing the alternative pathway of leukotriene A4. The structural characterization of biologically active phospholipid products of phospholipid oxidation will be a focus of a collaborative project to characterize those oxidized phospholipid products that may induce the anti-inflammatory macrophage phenotype. A second collaborative study will involve the characterization of oxidized phospholipid products that stimulate cyclooxygenase gene induction in endothelial cells. Finally, a method to collect lipid peroxidation products present in aerosols of expired breath in human subjects will be investigated. This novel, non-invasive method will be used to assess lipid peroxidation events in the lung that can be quantitated through measurement of markers using mass spectrometric techniques. Studies of human subjects with upper airway, lower airway, and alveolar lung disease will be undertaken using these techniques of collecting non- volatile molecules in expired breath and quantitation of specific products of arachidonate peroxidation.