RESPIRATORY ENDOTHELIAL INJURY BY XANTHINE OXIDASE

我们最近克隆了两个人类基因(AOX1和AOX2)，它们编码 强制性氧自由基产生酶，醛氧化酶(AO) 和 在这种钼中发现了意想不到的遗传复杂性 羟基酶家族，包括黄嘌呤氧化酶(XO)。它还 出现 AO可能导致急性肺漏：首先，是AO，但不是XO， 曾经是 在人的肺中表达。第二，用苯二酚或 SKF-525 (血管紧张素转换酶抑制剂)，而不是别嘌醇(XO抑制剂)减少 肺 气管内注射白介素1(IL-1)的大鼠渗漏。第三, 肺 给予AO底物的切片产生过氧化氢，观察到更多的过氧化氢 使用 肺组织电子显微镜下氯化铈染色的研究 IL-1 Than 对照组或IL-1和AO抑制剂处理的大鼠 我们的具体假设是，AO产生的O2自由基对 至 急性肺铅。 我们的具体目标是： 1.人和大鼠AOX1和AOX2基因的DNA特征 序列 分析、功能表达、抗原图和氨基酸 序列分析。 2.测定血管紧张素转换酶活性水平及细胞定位 和 人和大鼠肺组织中AO抗原和mRNA表达的特征 由In 原位杂交、免疫组织化学和组织化学。 3.探讨急性冠脉综合征的发病机制。 肺 在活体内泄漏。 提出这项建议的主要理据是： (A)在人肺中表达的是AO，而不是XO，这表明 到目前为止还不清楚的氧自由基产生途径 急性 肺漏(即所谓的急性呼吸窘迫综合征， ARDS)。 (B)AO和XO的结构、表达和调控 他们的 需要确定基因才能理解它们的特异性和 可能 氧自由基对肺的不同功能贡献 漏水。 (C)联合分析大鼠和人类的AO基因将使我们能够 至 确定急性呼吸窘迫综合征的重要性，并评估 操纵AO以预防人类的急性肺漏(ARDS)。

We recently cloned two human genes (AOX1 and AOX2) that encode the obligatory oxygen radical generating enzyme, aldehyde oxidase (AO) and discovered unanticipated genetic complexity in this molybdenum hydroxylase family which includes xanthine oxidase (XO). It also appears that AO could contribute to acute lung leak: First, AO, but not XO, was expressed in human lung. Second, treatment with benzoquinone or SKF-525 (AO inhibitors), but not allopurinol (an XO inhibitor), decreased lung leak in rats given interleukin-1 (IL-1)-intratracheally. Third, lung slices given AO substrate made H2O2, and more H2O2 was observed using cerium chloride staining in electron micrographs of lungs given IL-1 than in control or IL-1 and AO inhibitor treated rats Our specific hypothesis is that AO generated O2 radicals contribute to acute lung lead. Our specific aims are: 1. To characterize human and rat AOX1 and AOX2 genes by DNA sequence analysis, functional expression, antigenic mapping, and amino acid sequence analysis. 2. To determine the levels and cellular localization of AO activity and characterize AO antigen and mRNA expression in human and rat lung by in situ hybridization, immunochemistry, and histochemistry. 3. To determine the contribution of AO to the development of acute lung leak in vivo. The primary justification for the proposed approach is that: (a) The expression of AO,but not XO, in the human lung suggests a heretofore unrecognized pathway for oxygen radical generation in acute lung leak (the so called acute respiratory distress syndrome, ARDS). (b) The structures, expression and regulation of AO and XO and their genes needs to be determined to understand their specific and possibly different functional contributions to oxygen radical mediated lung leak. (c) Combined analysis of the rat and human AO genes will enable us to determine the significance of AO and to assess the potential for manipulating AO to prevent acute lung leak (ARDS) in humans.