VITAMIN E, OXIDANT STRESS AND PULMONARY ARACHIDONATE

拟议研究的主要目标是继续我们目前的 对分子基础的阐明的研究 对前列腺素(PG)和白三烯(LT)生物合成的调节 维生素E和硒(Se)。我们的假设是维生素E 和/或缺硒可影响相关关键酶的表达 通过PG和LT的生物合成以及它们在肺中的产物分布， 而这种改变的二十烷类化合物合成在一定程度上是导致 损害一些重要的生理功能，包括 对免疫系统的影响。这一假设是基于这样一个前提，即胖子 酸性过氧化氢(FAHPs)和自由基是PG和 它的生物合成。因此，通过保持临界浓度， FAHP和必需自由基、Se-GSH-Px和维生素E具有 有可能调节花生四烯酸的级联反应。 拟议的研究的具体目标是确定表达 (1)环氧合酶和5-脂氧合酶，它们催化第一 PG和LT生物合成的关键步骤；(2)关键酶LTC4合成酶 参与硫化物LTS的生物合成；和(3)微粒体谷胱甘肽 S转移酶是谷胱甘肽/谷胱甘肽依赖性的重要蛋白 抗氧化剂对肺膜过氧化损伤的保护作用 在维生素E和/或硒缺乏期间。其他具体目标为(4)至 详细研究饮食中维生素E和硒的状况对人体的影响 巨噬细胞和中性粒细胞在肺内产生细胞因子，以及(5) 为了研究维生素E和缺硒之间的潜在关系， 细胞因子的产生和花生四烯酸代谢对血管病变的影响 淋巴细胞功能。我们建议使用臭氧暴露作为额外的 氧化应激模型进一步阐明调控机制 维生素E和硒在前列腺癌和前列腺癌中的抗氧化防御功能 它的生物合成。 分子探针，如多克隆抗体、单抗和 将被用来确定改变的维生素的影响 E和Se营养对相关关键酶表达的影响 花生四烯酸级联反应是在翻译水平或 转录水平。我们还计划评估这种酶的作用 通过确定产品配置文件来确定活跃度。这些实验将会 还包括检查维生素E和/或硒的直接影响 白细胞产生细胞因子的缺陷--以及间接的 已知受维生素E改变影响的二十烷基类化合物的作用 和硒营养。最后，其他实验将检验 可能解释增殖性和细胞毒性降低的机制 维生素E和/或硒缺乏对淋巴细胞功能的影响。 我们的长期目标是确定PG和LTS在 氧化应激下呼吸系统疾病的病理生理学研究 维生素E中的抗氧化防御功能受损-- 和/或缺硒状态。

The primary objective of the proposed research is to continue our current investigations into the elucidation of the molecular basis for the regulation of prostaglandin (PG) and leukotriene (LT) biosynthesis by vitamin E and selenium (Se). Our working hypotheses are the vitamin E and/or Se deficiency can influence the expression of key enzymes associated with PG and LT biosynthesis as well as their product profiles in the lung, and this altered eicosanoid synthesis is, in part, responsible for the impairment of a number of critical physiological functions, including those of the immune system. this hypothesis is based on the premise that fatty acid hydroperoxides (FAHPs) and free radicals are integral parts of PG and LT biosynthesis. Therefore, by maintaining the critical concentrations of FAHPs and essential free radicals, Se-GSH-Px and vitamin E have the potential to modulate the arachidonic acid cascade. The specific aims of the proposed research are to determine the expression of (1) cyclooxygenase and 5-lipoxygenase, which catalyze the first committed step in PG and LT biosynthesis; (2) LTC4 synthase, a key enzyme involved in the biosynthesis of sulfido LTs; and (3) microsomal glutathione S-transferase, an important protein responsible for GSH/GSSG-dependent antioxidant protection against membrane peroxidative damage in the lung during vitamin E and/or Se deficiency. Additional specific aims are (4) to examine in detail, the role of dietary vitamin E and Se status on the production of cytokines in the lung by macrophages and neutrophils, and (5) to examine the potential relationships of vitamin E and Se deficiency, cytokine production, and arachidonic acid metabolism to alterations in lymphocyte function. We propose to employ ozone exposure as an additional oxidant stress model to delineate further the regulatory mechanisms underlying the antioxidant defense functions of vitamin E and Se in PG and LT biosynthesis. Such molecular probes as polyclonal antibodies, monoclonal antibodies and cDNAs, will be employed to determine whether the effects of altered vitamin E and Se nutrition on the expression of key enzymes associated with the arachidonic acid cascade are at the translational level or the transcriptional level. We also plan to assess the effects at the enzyme activity level by determining the product profiles. The experiments will also include the examination of direct effects of vitamin E and/or Se deficiency on cytokine production by leukocytes -- as well as indirect effects mediated by eicosanoids known to be affected by altered vitamin E and Se nutrition. Finally, additional experiments will examine the mechanisms that may explain the decreased proliferative and cytotoxic capabilities of lymphocytes by vitamin E and/or Se deficiency. Our long range objective is to establish the precise role of PGs and LTs in the pathophysiology of oxidant-induced respiratory diseases under such compromised antioxidant defense functions as those seen in vitamin E- and/or Se-deficient states.