Reactive oxygen species and anti-oxidants in ALI

描述（由申请人提供）： 该应用代表了多学科的努力，以调查肺防御氧化应激的机制。该计划的假设是，处于风险中的患者中活性氧物质（ROS）的产生在肺损伤的起始中起关键作用，导致以急性肺损伤（AL 1）综合征为高潮的一连串事件。主要的重点将是抗氧化酶保护，特别关注新描述的肺抗氧化酶，过氧化物酶6（Prdx 6）。在R-01支持研究这种酶的一段时间内产生的结果表明，Prdx 6可以减少磷脂氢过氧化物，这为通过逆转膜脂质过氧化作用保护免受氧化应激提供了基础。我们将利用小鼠模型的改变Prdx 6的表达，以确定这种酶在抗氧化防御的作用，将评估控制Prdx 6的表达在氧化应激下，并将表征生化要求的酶活性与磷脂氢过氧化物的结合和催化。我们将鉴定与严重创伤患者急性淋巴细胞白血病风险增加相关的特定抗氧化基因的功能多态性。多态性的功能意义将通过分析启动子区（如果相关）或突变蛋白的表达来确定。我们将采用物理、质谱和蛋白质组学技术来表征Prdx 6的寡聚化和氧化修饰，以及确定Prdx 6表达水平对氧化应激期间其他肺蛋白氧化修饰的影响。我们还将寻找诊断氧化应激和ALL发展的血液蛋白水平的变化。我们将通过使用聚合物纳米载体将抗氧化酶递送到内皮来研究抗氧化防御的新策略。一个主要的重点将是Prdx 6的胞质传递。我们将得到以下方面的支持：1）临床、生物统计和数据管理; 2）分子工程和蛋白质制备; 3）细胞培养和畜牧业。这代表了基础科学和转化研究，其将为ROS介导的ALL 1的抗氧化防御和潜在的基于机制的疗法提供新的见解。

DESCRIPTION (provided by applicant): This application represents a multidisciplinary effort to investigate the mechanisms for lung defense against oxidative stress. The hypothesis for the program is that generation of reactive oxygen species (ROS) in patients at risk plays a critical role in the initiation of lung damage leading to a cascade of events that culminates in the syndrome of acute lung injury (ALl). The major focus will be on antioxidant enzymatic protection with special focus on a newly described lung antioxidant enzyme, peroxiredoxin 6 (Prdx 6). Results generated during a period of R-01 support to study this enzyme indicate that Prdx 6 can reduce phospholipid hydroperoxides which provides a basis for protection against oxidant stress through reversal of membrane lipid peroxidation. We will utilize mouse models of altered Prdx 6 expression to determine the role of this enzyme in antioxidant defense, will evaluate control of Prdx 6 expression under oxidant stress, and will characterize the biochemical requirements for enzymatic activity with respect to binding and catalysis of phospholipid hydroperoxides. We will identify functional polymorphisms in specific antioxidant genes that are associated with an increased risk of ALl among patients with major trauma. The functional significance of the polymorphisms will be determined by analysis of the promoter region, if relevant, or expression of the mutant protein. We will employ physical, mass spectrometric, and proteomic techniques to characterize oligomedzation and oxidative modification of Prdx 6 as well as to determine the effects of Prdx 6 expression levels on oxidative modification of other lung proteins dudng oxidative stress. We will also search for changes in blood proteins levels that are diagnostic of oxidative stress and development of ALl. We will investigate a novel strategy for anti-oxidant defense through use of polymer nanocarriers for delivery of antioxidant enzymes to endothelium. A major emphasis will be on the cytosolic delivery of Prdx 6. We will be supported by: 1) clinical, biostatistical and data management; 2) molecular engineering and protein preparation; and 3) cell culture and animal husbandry. This represents both basic science and translational studies that will provide new insights into antioxidant defense and potential mechanistic-based therapies for ROS-mediated ALl.