Nitrated Fatty Acids, Novel Anti-inflammatory Mediator in Allergic Airway Disease

摘要 哮喘是一种高度流行的呼吸道疾病，是一种主要的公共卫生问题，现有的治疗方法 选择不充分。内源性硝化脂肪酸(NFAs)被认为是由NO产生的，它有 最近被鉴定为存在于人血浆中的重要生物活性化合物。虽然调查了 它们的生物活性还处于早期阶段，越来越多的证据表明它们具有强大的抗炎作用。 分子。我们的初步数据显示，外源性NFAs的使用可以显著减弱 过敏性呼吸道疾病小鼠模型的病理生理表现，而内源性抑制 NFA的合成会加剧过敏反应。非饱和脂肪酸激活核转录因子过氧化物酶 增殖物激活受体(PPAR)在某些细胞类型中的表达，我们发现过敏反应是 当PPAR-在基因上被消除，但通过在呼吸道中的过度表达而减弱时，病情加重 活体内的上皮细胞。因此，我们建议检验以下假设：呼吸道上皮细胞的激活 硝化脂肪酸的PPAR-？显著抑制过敏性呼吸道疾病的影响，包括 炎症和粘液产生。我们的具体目标是：1)确定NFA调节的程度 肺中PPAR活性和小鼠过敏性呼吸道疾病的严重程度，我们将使用小鼠 结构性缺乏所有三种亚型的一氧化氮合酶(三种一氧化氮合酶基因敲除)，因此预计 缺乏NFAs；2)确定气道上皮细胞中PPAR-1的激活是否介导了NFAs的抑制能力 过敏原攻击在小鼠过敏性呼吸道疾病中的作用，我们将利用PPAR-1或PPAR-1的小鼠 在呼吸道上皮细胞中选择性地敲除或过度表达；以及3)确定NFAs是否抑制 培养的人呼吸道上皮细胞产生趋化因子和粘液及其程度 影响是通过PPAR依赖和/或PPAR不依赖的机制来调节的，为此我们将 使用基因沉默和化学抑制来抑制PPAR-β，同时测试其他信号的激活 小路。对于目标1和目标2，我们将使用已建立的小鼠过敏性呼吸道疾病模型 蟑螂变应原，而Aim 3将使用分化良好的原代人支气管在体外进行 上皮细胞生长在气液界面。验证我们的假设将确定和阐明 一种新的内源性物质调节过敏性呼吸道疾病严重程度的机制 并可能为哮喘开辟新的治疗途径和治疗方法。

ABSTRACT Asthma is a highly prevalent airway disease that is a major public health problem for which available treatment options are inadequate. Endogenous nitrated fatty acids (NFAs), thought to be produced from NO, have recently been identified as important bioactive compounds present in human plasma. Although investigation of their biological activities is at an early stage, evidence is accumulating that they are potent anti-inflammatory molecules. Our preliminary data show that administration of exogenous NFAs can significantly attenuate pathophysiologic manifestations in a murine model of allergic airway disease, whereas inhibiting endogenous NFA synthesis exacerbates allergic responses. NFAs activate the nuclear transcription factor peroxisome proliferator-activated receptor-¿ (PPAR-¿) in some cell types, and we have found that allergic responses are exacerbated when PPAR-¿ is genetically eliminated but are attenuated by overexpression of PPAR-¿ in airway epithelial cells in vivo. Accordingly, we propose to test the hypothesis that activation of airway epithelial cell PPAR-¿ by nitrated fatty acids significantly suppresses the effects of allergic airway disease, including inflammation and mucus production. Our Specific Aims are: 1) to determine the extent to which NFAs modulate PPAR-¿ activity in the lung and the severity of murine allergic airway disease, for which we will use mice constitutively lacking all three isoforms of nitric oxide synthase (triple NOS knockout) and therefore expected to lack NFAs; 2) to determine whether PPAR-¿ activation in airway epithelial cells mediates NFAs' ability to inhibit effects of allergen challenge in murine allergic airway disease, for which we will utilize mice with PPAR-¿ either knocked out or overexpressed selectively in airway epithelial cells; and 3) to determine whether NFAs inhibit chemokine and mucus production in cultured human airway epithelial cells and the extent to which these effects are mediated through PPAR-¿-dependent and/or PPAR-¿-independent mechanisms, for which we will use gene silencing and chemical inhibition to suppress PPAR-¿ while testing for activation of other signaling pathways. For Aims 1 and 2 we will utilize an established murine model of allergic airway disease induced by cockroach allergen, while Aim 3 will be carried out in vitro using well differentiated primary human bronchial epithelial cells grown at an air-liquid interface. Validation of our hypothesis will identify and elucidate the mechanisms through which a novel endogenous substance modulates the severity of allergic airway disease and may lead to new therapeutic avenues and treatments for asthma.