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

描述（由申请人提供）：哮喘是一种高度流行的气道疾病，是一个主要的公共卫生问题，现有的治疗方案不足。内源性硝化脂肪酸（nfa）被认为是由一氧化氮产生的，最近已被确定为存在于人血浆中的重要生物活性化合物。虽然对其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，外源性NFA可以显著减轻小鼠变应性气道疾病模型的病理生理表现，而抑制内源性NFA合成则会加剧过敏反应。NFAs激活核转录因子过氧化物酶体增殖物激活受体？（PPAR-?）存在于某些细胞类型中，我们发现当PPAR-？在基因上被消除，但由于PPAR-？在气道上皮细胞体内。因此，我们提出验证气道上皮细胞PPAR-？通过硝化脂肪酸显著抑制过敏性气道疾病的影响，包括炎症和粘液的产生。我们的具体目标是：1)确定NFAs调节PPAR-？肺部活动和小鼠过敏性气道疾病的严重程度，为此，我们将使用缺乏所有三种一氧化氮合酶同种异构体的小鼠（三重NOS敲除），因此预计缺乏NFAs；2)确定PPAR-？在小鼠过敏性气道疾病中，气道上皮细胞的激活介导了nfa抑制过敏原攻击的能力，为此我们将利用PPAR-？在气道上皮细胞中选择性敲除或过表达；3)确定NFAs是否抑制培养的人气道上皮细胞中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-？我们将利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。在Aims 1和Aims 2中，我们将使用已建立的蟑螂过敏原诱导的小鼠变应性气道疾病模型，而Aim 3将在体外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。我们假设的验证将确定和阐明一种新的内源性物质调节过敏性气道疾病严重程度的机制，并可能导致哮喘的新治疗途径和治疗方法。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，并可能开发哮喘治疗的新方法和新药物。

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.