OXIDANTS AND ENDOTOXIN INDUCED ENDOTHELIAL INJURY

描述(改编自申请者摘要)：申请者将 进一步追踪观察到细胞内产生的反应性 氧物种(ROS)参与内毒素刺激的前列腺素 肺内皮细胞合成和释放。两个密切相关的 假设是基于初步数据提出的 内毒素导致细胞内ROS的产生，而抗氧化剂， DMSO以及细胞外产生的一氧化氮(NO)和 过氧亚硝酸盐(ONOO)抑制内毒素刺激的前列腺素释放 是细胞内产生ROS的结果，包括产生和 细胞内NO和ONOO的可用性和(Ii)抗氧化剂和 细胞内NO和ONOO超常水平抑制内毒素刺激 前列腺素合成通过对ecNOS和COX-2mRNA的影响。都不是 和ONOO被普遍认为是介导氧化组织损伤的媒介，但是 最近有报道称，它们的过度繁殖既赋予了它们 有益的和有害的影响。拟议的实验代表了一种 综合运用细胞的三个具体目标和技术 生物学、生物化学和分子生物学。建议进行实验，以 测定：1)诱导型一氧化氮合酶和环氧合酶-2的时间进程 暴露于内毒素以及这是否是细胞内的后果 氧化应激，2)外源产生的NO和ONOO对细胞的影响 内毒素反应以及观察到的有益效果是否 细胞内水平变化的结果，以及，3)是否 通过基因工程高表达NO的内皮细胞受到保护 从内毒素诱导的前列腺素合成和释放。自.以来 初步数据还表明，牛的iNOS活性存在差异 肺动脉内皮细胞与牛肺微血管 细胞(BMVEC)，申请人将检查BPAEC和BMVEC中的1)和2)； 从这两个相同地点培养的人类细胞也将被检测，因为 这是必要的。加深对内毒素诱导的机制(S)的理解 内皮细胞的变化将导致改善和创新的战略 成人呼吸窘迫综合征患者的治疗。

DESCRIPTION (Adapted from the applicant's abstract): The applicant will further pursue the observation that intracellular generation of reactive oxygen species (ROS) contributes to endotoxin-stimulated prostanoid synthesis and release from pulmonary endothelium. Two closely associated hypotheses are proposed based on preliminary data demonstrating that endotoxin causes intracellular generation of ROS, and that the antioxidant, DMSO, as well as extracellularly generated nitric oxide (NO) and peroxynitrite (ONOO) downregulate endotoxin-stimulated prostaglandin release is the result of intracellular generation of ROS, including generation and availability of intracellular NO and ONOO and (ii) antioxidants and supranormal levels of intracellular NO and ONOO inhibit endotoxin-stimulated prostaglandin synthesis through effects on ecNOS and COX-2 mRNA. Both NO and ONOO have been generally thought to mediate oxidant tissue injury, but their excessive generation has recently been reported to confer both beneficial and deleterious effects. The proposed experiments represent a comprehensive approach to three specific aims and utilize techniques of cell biology, biochemistry and molecular biology. Experiments are proposed to determine: 1) the time course of induction of ecNOS and COX-2 following exposure to endotoxin and whether this is a consequence of intracellular oxidant stress, 2) the effects of exogenously generated NO and ONOO on the endotoxin response and whether the observed beneficial effects are the result of alterations in their intracellular level and, 3) whether endothelial cells genetically engineered to hyperexpress NO are protected from endotoxin-induced prostaglandin synthesis and release. Since the preliminary data also indicate differences in iNOS activity in bovine pulmonary artery endothelial cells (BPAEC) and bovine lung microvascular cells (BMVEC), the applicant will examine 1) and 2) in both BPAEC and BMVEC; human cells cultured from those same two sites will also be examined, as necessary. Improved understanding of the mechanism(s) of endotoxin-induced endothelial changes will result in improved and novel strategies for treatment of patients with the adult respiratory distress syndrome.