Isoeicosanoids& Biologically Active Oxidized Phospholipi

脂质过氧化是一种自然发生的过程，在一定程度上保护细胞和细胞大分子免受活性氧的影响。现在人们普遍认识到，脂质过氧化也会导致介导细胞对自由基过程的反应的生物活性产物。此外，在脂质过氧化过程中形成反应性化学实体，其具有足够的亲电性以共价修饰蛋白质和其他生物聚合物。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的自由基氧化过程中发生的初始化学事件。个体研究的主要焦点将围绕花生四烯酸的氧化，花生四烯酸是过氧化事件的特别敏感的靶点。质谱法将用作氧化磷脂结构表征的主要工具。将进行亲电脂质自由基产物和靶蛋白的共价加合物的结构研究，以确定加合物形成的位点和开发的技术，以确定共价加合物的脂质部分的结构。第二个主要焦点将被开发，以确定共价加合物的脂质部分的结构。第二个主要重点将是测试白三烯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。第二个合作研究将涉及氧化磷脂产品的特性，刺激环氧合酶基因诱导内皮细胞。最后，将研究收集人类受试者呼出气溶胶中存在的脂质过氧化产物的方法。这种新的非侵入性方法将用于评估肺中的脂质过氧化反应，可以通过使用质谱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花生四烯酸过氧化的特定产物的这些技术对患有上呼吸道、下呼吸道和肺泡肺疾病的人类受试者进行研究。

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.