Nitrated Fatty Acids, Novel Anti-inflammatory Mediators in Allergic Airway Diseas

描述(申请人提供)：哮喘是一种高度流行的呼吸道疾病，是一个重大的公共卫生问题，现有的治疗选择不充分。内源性硝化脂肪酸(NFAs)被认为是由NO产生的，最近被确定为存在于人类血浆中的重要生物活性化合物。虽然对它们的生物活性的研究还处于早期阶段，但越来越多的证据表明它们是有效的抗炎分子。我们的初步数据显示，给予外源性NFA可以显著减轻过敏性呼吸道疾病小鼠模型的病理生理表现，而抑制内源性NFA的合成会加剧过敏反应。NFA激活了核转录因子--过氧化物酶体增殖物激活受体？(PPAR-？)在某些细胞类型中，我们发现当PPAR-？在基因上被消除，但通过PPAR-的过度表达而减弱？在体内的呼吸道上皮细胞中。因此，我们建议检验以下假设：呼吸道上皮细胞PPAR-？通过硝化脂肪酸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对PPAR-？肺活动和小鼠过敏性呼吸道疾病的严重程度，为此，我们将使用结构性缺乏所有三种亚型一氧化氮合酶(三重一氧化氮合酶基因敲除)的小鼠，因此预计缺乏NFAs；2)确定PPAR-？在小鼠过敏性呼吸道疾病中，气道上皮细胞的激活介导了NFAs抑制变应原攻击的能力，为此，我们将利用PPAR-？3)确定NFAs是否抑制培养的人呼吸道上皮细胞的趋化因子和粘液的产生，以及这些作用在多大程度上是通过PPAR依赖和/或PPAR非依赖的机制介导的，为此，我们将使用基因沉默和化学抑制来抑制PPAR-？同时测试其他信号通路的激活。对于目标1和目标2，我们将利用已建立的蟑螂变应原诱导的过敏性呼吸道疾病的小鼠模型，而目标3将使用在气液界面生长的分化良好的原代人支气管上皮细胞进行体外实验。验证我们的假设将识别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，并可能导致新的治疗途径和治疗哮喘的方法。公共卫生相关性：哮喘是一种严重的、高度流行的肺部疾病。我们的研究将确定最近在我们体内发现的物质是否会减少过敏性呼吸道反应。我们将确定这些物质的作用机制，从而更好地了解哮喘的潜在过程，并可能开发新的哮喘治疗方法和药物。

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: Asthma is a serious, highly-prevalent lung disease. Our research will determine whether substances recently identified within our bodies reduce allergic airway responses. We will determine the mechanisms by which these substances act, leading to a better understanding of the processes underlying asthma and possibly to development of new approaches and agents for asthma therapy.