Reactive oxygen species and anti-oxidants in ALI

描述(由申请人提供)： 这项应用代表了一项多学科的努力，以研究肺对氧化应激的防御机制。该计划的假设是，在有风险的患者中，活性氧物种(ROS)的产生在启动肺损伤导致一系列事件，最终导致急性肺损伤(ALL)综合征方面发挥关键作用。主要的焦点将放在抗氧化剂的酶保护上，特别是一种新描述的肺抗氧化酶--过氧化还蛋白6(PRDX 6)。在R-01支持期间对该酶的研究结果表明，PRDX-6可以减少磷脂过氧化，这为通过逆转膜脂过氧化来对抗氧化应激提供了基础。我们将利用PRDX 6表达改变的小鼠模型来确定该酶在抗氧化防御中的作用，评估在氧化应激下对PRDX 6表达的控制，并将表征与磷脂氢过氧化物结合和催化有关的酶活性的生化要求。我们将确定特定抗氧化剂基因的功能多态性，这些基因与严重创伤患者急性淋巴细胞白血病的风险增加相关。多态的功能意义将通过分析启动子区域(如果相关)或突变蛋白的表达来确定。我们将使用物理、质谱学和蛋白质组学技术来表征PRDX 6的寡聚化和氧化修饰，并确定在氧化应激过程中PRDX 6的表达水平对其他肺蛋白质氧化修饰的影响。我们还将寻找血液蛋白质水平的变化，以诊断氧化应激和ALL的发展。我们将研究一种新的策略，通过使用聚合物纳米载体将抗氧化酶输送到内皮细胞来进行抗氧化防御。主要的重点将放在PRDX 6的胞液输送上。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性研究，将为ROS介导的ALL的抗氧化防御和潜在的基于机制的治疗提供新的见解。

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.