PLASMA PROTEIN MODIFICATIONS AS BIOMARKERS OF OXIDATIVE

氧化应激被认为是 支气管肺发育不良(BPD)与成人呼吸系统疾病的发病机制 窘迫综合征(ARDS)。氧化应激可以被定义为 关键组织靶点氧化所产生的致病后果 由活性物质以超过组织的速度产生 抗氧化能力。然而，只有少数几项研究直接测量 BPD或ARDS患者的活性物质或氧化应激 都是可用的。测量活性物种的一个主要限制是 它们在生物系统中短暂的半衰期。由于活性物质 修饰生物分子，如蛋白质、脂质和DNA测量 为他们的研究提供了实验工具 检测和量化。此应用程序中的初步数据 表明血清蛋白变化量为2，4 二硝基苯肼、反应酮和酪氨酸的硝化 残留可能表明BPD和ARDS中存在氧化应激。蛋白 羰基是由氨基酸残基直接氧化而来的。 不饱和脂肪酸氧化生成的醛的共轭反应 脂类或糖。总体而言，血浆蛋白羰基表明 氧化剂的形成。蛋白质酪氨酸残基的硝化结果 在3-硝基酪氨酸的形成中。之前我们发现， 过氧亚硝酸根与二氧化碳的反应提供了必要的硝化作用 解释血浆蛋白3-硝基酪氨酸形成的试剂。 过氧亚硝酸盐是由近乎扩散限制的反应形成的 一氧化氮和超氧化物。因此，此应用程序将 系统检测BPD患者这些生物标志物的变化 还有ARDS。我们认为这些蛋白质修饰表明 氧化剂和硝化物种的产生，并与 患者病情的严重程度和致命后果。关键方面 我们的假设将通过：1)将血浆蛋白关联起来 BPD和ARDS严重程度患者血清3-硝基酪氨酸水平变化 临床疾病和转归。2)检测血浆蛋白的变化 ARDS和BPD患者术后3-硝基酪氨酸和羰基水平的变化 吸入治疗水平的一氧化氮。此应用程序是 通过已建立的患者采血方案得到加强 和加工，测量这些生物标志物的经验 以及对这些生物的生化起源的理解 记号笔。

Oxidative stress is considered to be a significant component in the pathogenesis of bronchoplumonary dysplasia (BPD) and adult respiratory distress syndrome (ARDS). Oxidative stress can be defined as the pathogenic outcome created by the oxidation of critical tissue targets by reactive species which are generated at rates exceeding tissue antioxidant capacity. However, only few studies that directly measure reactive species or oxidative stress in patients with either BPD or ARDS are available. A major limitation for measuring reactive species is their short half life in biological systems. Since reactive species modify biological molecules such as proteins, lipids and DNA measurement of the modified targets provide the experimental tools for their detection and quantification. Preliminary data in this application indicate that serum protein modifications measured as 2, 4 dinitrophenylhydrazine reactive carbonyls and nitration of tyrosine residues may be indicate oxidative stress in BPD and ARDS. Protein carbonyls are derived by the direct oxidation of amino acid residues conjugation of aldehydes that formed by the oxidation of unsaturated lipids or sugars. Overall, plasma protein carbonyls indicate the formation of oxidants. Nitration of protein tyrosine residues results in the formation of 3-nitrotyrosine. Previously we found that the reaction of peroxynitrite with C02 provides the necessary nitrating agent that explains the formation of plasma protein 3-nitrotyrosine. Peroxynitrite is formed by the nearly diffusion limited reaction of nitric oxide and superoxide. Therefore this application will systematically examine the changes in these biological markers in BPD and ARDS. We propose that these protein modifications indicate generation of oxidants and nitrating species and correlate with the severity of patient's illness and fatal outcome. The critical aspects of our hypothesis will be tested by: 1) correlating the plasma protein levels of 3-nitrotyrosine in BPD and ARDS patients with the severity of clinical illness and outcome. 2) measuring the changes in plasma protein levels of 3-nitrotyrosine and carbonyls in ARDS and BPD patients after inhalation of therapeutic levels of nitric oxide. This application is strengthened by the established protocols for patient blood collection and processing, the experience with measuring these biological markers and the understanding of the biochemical origin of these biological markers.