OXYRADICALS IN THE PATHOGENESIS OF BRONCHOPULMONARY DYSPLASIA

支气管肺发育不良发病机制中的氧化自由基

• 批准号: 5213874
• 负责人: JERRY L ZIMMERMAN
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5213874
• 关键词: DNA damage; annexins; apolipoproteins; bronchopulmonary dysplasia; clinical research; clinical trials; dietary supplements; disease /disorder model; free radical oxygen; high performance liquid chromatography; human subject; leukocyte activation /transformation; lung injury; mass spectrometry; nutrition related tag; oxidative stress; pathologic process; peroxidation; phospholipids; premature infant human; pulmonary surfactants; respiratory distress syndrome of newborn; respiratory epithelium; tissue /cell culture; tocopherols; xanthine oxidase

Respiratory distress syndrome/bronchopulmonary dysplasia (RDS/BPD) represent the most common cause of mortality and morbidity in the premature infant. Although the cause of RDS has been established to be immaturity of the pulmonary surfactant system, the etiology of BPD is probably multifactorial and certainly ill defined. There exists a number of indirect observations which implicate oxyradicals in the pathogenesis of BPD, however direct evidence linking oxyradical macromolecular injury and clinical development of BPD is meager at best. The overall goal of Project #1 in this SCOR proposal is to provide direct evidence of oxyradical macromolecular injury in infants during the acute phase of BPD. Furthermore, this investigation will examine oxyradical injury toward cultured alveolar type II pneumocytes as a BPD model of in vitro oxyradical injury. The clinical aspect of this investigation will analyze both endotracheal aspirate, as well as plasma samples from intubated, cannulated premature infants with RDS during the during development of acute BPD. These samples will be fractionated and analyzed for their fatty acid profiles (including perhydroxyl derivatives of polyunsaturated fatty acids), malondialdehyde and vitamin E isomers utilizing the techniques of high performance liquid chromatography and gas chromatograph/mass spectroscopy. Endotracheal aspirates will additionally be serially assessed for protein concentration and myeloperoxidase activity, and phospholipid binding protein and surfactant associated protein A as markers for inflammation and type II cell alteration respectively. Infants enrolled In the clinical study will be nutritionally supplemented with vitamin E and polyunsaturated fatty acids to normalize these constituents so that these variables will be controlled. Severity of illness in these infants will be determined by a number of validated clinical scoring systems, while BPD will be diagnosed on day 21 of life utilizing clinical and radiographic criteria. In addition to the clinical studies a series of experiments involving oxyradical stress on cultured alveolar type II pneumocytes will also be pursued. These investigations will examine the.potential of various oxidant stresses (hydrogen peroxide, glucose oxidase, xanthine oxidase, neutrophils. hyperoxia) to mediate macromolecular (lipid, protein, nucleic acid) injury. Analyses of lipid peroxidation products will be performed in a fashion identical to the clinical investigation. Determination of sulfhydryl redox state will reflect oxygen stress toward type II cell protein while sensitive analyses of DNA conformation will reveal oxidant damage towards nucleic acid. Susceptibility towards oxyradical stress in cultured adult type 11 cells will be compared to that of fetal type II cells. Utilizing the combined approach of clinical as well as cell culture studies the investigators expect to provide direct evidence that oxyradicals are associated with the pathogenesis of BPD.

呼吸窘迫综合征/支气管肺发育不良（RDS/BPD） 代表了早产的死亡率和发病率的最常见原因 婴儿。 尽管已确定了RDS的原因是不成熟的 肺表面活性剂系统，BPD的病因可能是 多因素，当然是不明显的。 存在许多 间接观察结果，这意味着草中的发病机理 BPD，但是直接证据联系起来，将大写的大分子损伤和 BPD的临床发展充其量是微不足道的。 项目的总体目标 在此SCOR提案中＃1是提供直接证据 BPD急性期婴儿的大分子损伤。 此外，这项调查将检查对草的损伤 培养的牙槽II型肺炎细胞作为体外草皮的BPD模型 受伤。 这项调查的临床方面将分析 气管气管抽吸物以及来自插管的插管的血浆样品 在急性BPD发育期间，患有RDS的过早婴儿。 这些样品将被分馏并分析其脂肪酸 轮廓（包括多不饱和脂肪的旁羟基衍生物 酸），利用丙二醛和维生素E异构体利用技术的技术 高性能液相色谱和气相色谱/质量 光谱法。 气管气管抽吸将另外还要连续 评估蛋白质浓度和骨髓过氧化物酶活性，以及 磷脂结合蛋白和表面活性剂相关蛋白A作为标记 分别用于炎症和II型细胞改变。 婴儿 参加临床研究将在营养中补充 维生素E和多不饱和脂肪酸以使这些成分标准化 这样这些变量将被控制。 这些疾病的严重程度 婴儿将由许多经过验证的临床评分决定 系统，而BPD将在使用临床的生活的第21天诊断 和影像学标准。 除临床研究外 涉及培养的牙槽II型的草本应激的实验 还将追求肺细胞。 这些调查将检查 各种氧化应激的竞争力（过氧化氢，葡萄糖 氧化酶，黄嘌呤氧化酶，中性粒细胞。高氧）进行介导 大分子（脂质，蛋白质，核酸）损伤。 脂质分析 过氧化产品将以与 临床研究。 磺胺氧化还原状态的确定将 反映对II型细胞蛋白的氧气应激，而敏感分析 DNA构象的构象会揭示对核酸的氧化损伤。 在培养的成人11型细胞中对草本应激的敏感性 将与胎儿II型细胞的比较。 利用合并 临床和细胞培养研究的方法研究者 期望提供直接证据，表明草皮与 BPD的发病机理。