Nucleotide receptor modulation of airway eicosanoids during asthma exacerbations

描述（由申请人提供）：尽管最近鉴定了类二十烷酸介质，解决炎症，这些因素在感染过程中的调节还没有得到很好的理解。 哮喘急性发作通常由人鼻病毒感染引发，但缺乏时间敏感的、以患者为中心的工具来研究这些事件阻碍了急性哮喘治疗的发展。我们的长期目标是更全面地了解哮喘急性发作的解决方案，以加速康复。 我们已经表明，核苷酸受体P2 X7调节考克斯-2和PGE 2的表达（后者诱导促分解脂质，如脂氧素）。因此，本发明的总体目标是确定在体外和体内HRV感染期间调节类花生酸代谢酶的表达和功能的机制。 作为这一更广泛目标的一部分，中心假设是PGE 2和脂氧素的跨细胞生成受肺泡巨噬细胞中P2 X7诱导的考克斯-2表达的调节，并且该过程有助于解决HRV触发的恶化。 我们提出以下具体目标。SA 1）确定HRV感染期间跨细胞脂氧素产生的机制。我们的工作假设是，由HRV感染的上皮细胞引发增强P2 X7诱导的考克斯-2表达和肺泡巨噬细胞产生PGE 2，在这些条件下产生脂氧素需要气道上皮15-LO活性。这一目标的主要方法是利用轻度哮喘患者气道细胞的原代培养物来研究HRV感染期间控制考克斯-2和15-LO表达和活性的P2 X7依赖性机制。SA 2）识别与哮喘症状的快速缓解相关的HRV诱导的恶化期间的患者特征和气道样品类花生酸因子。工作假设是，相对于孔功能减弱的患者，P2 X7活性正常的哮喘患者在开始泼尼松爆发治疗HRV触发的急性加重后7天内哮喘指数消退的受试者比例更大，并且急性气道样本中的PGE 2水平更高。在这种情况下，主要的方法是在重度哮喘研究计划-3的纵向和加重方案的背景下，使用新开发的时间敏感工具哮喘指数来研究加重。 将评估P2 X7的功能能力、急性加重期间鼻分泌物中HRV的存在或不存在以及急性气道样本中PGE 2和LXA 4水平的水平，以确定其在缓解急性加重时作为生物标志物的作用。这一贡献是重要的，因为它是连续研究的第一步，预计将导致药理学策略的发展，这将允许患者个性化的管理策略，以更快地恢复哮喘控制，并代表了一个新的和实质性的偏离现状，通过使用跨细胞模型来确定体外机制，再加上严重哮喘研究计划的基础设施和时间敏感的哮喘指数。

DESCRIPTION (provided by applicant): Despite recent identification of eicosanoid mediators that resolve inflammation, the regulation of these factors during infection is not well understood. Asthma exacerbations are commonly triggered by infection with human rhinoviruses, but the lack of time-sensitive, patient-centered tools to study these events hinders development of acute asthma therapies. Our long-range goal is to more completely understand the resolution of asthma exacerbations, in order to hasten recovery. We have shown that the nucleotide receptor P2X7 regulates expression of cox-2 and PGE2 production (the latter of which induces pro-resolution lipids such as lipoxins). As such, the overall objective of the present proposal is o define the mechanisms regulating the expression and function of eicosanoid-metabolizing enzymes during infection by HRV in vitro and in vivo. As part of this broader objective, the central hypothesis is that transcellular generation of PGE2 and lipoxins is regulated by P2X7-induced cox-2 expression in alveolar macrophages, and that this process facilitates resolution of an HRV-triggered exacerbation. We propose the following Specific Aims. SA1) Determine the mechanisms of transcellular lipoxin generation during HRV infection. Our working hypothesis is that priming by HRV-infected epithelial cells enhances P2X7 induced cox-2 expression and PGE2 generation by alveolar macrophages, and that generation of lipoxins under these conditions requires airway epithelial 15-LO activity. The primary approach for this aim is to utilize primary cultures of airway cells from patients with mild asthma to study the P2X7-depndent mechanisms governing the expression and activity of cox-2 and 15-LO during infection with HRV. SA2) Identify the patient characteristics and airway sample eicosanoid factors during HRV- induced exacerbations that are associated with rapid resolution of asthma symptoms. The working hypothesis is that relative to those with attenuated pore function, asthma patients with normal P2X7 activity will have a greater proportion of subjects with a resolving Asthma Index within 7 days of starting a prednisone burst for an HRV-triggered exacerbation and have higher levels of PGE2 in acute airway samples. In this case, the primary approach is to study exacerbations with a newly developed time-sensitive tool, the Asthma Index, in the context of a Longitudinal and Exacerbation Protocols within the Severe Asthma Research Program-3. The functional capacity of P2X7, the presence or absence of HRV in nasal secretions during the exacerbation period and the levels of PGE2 and LXA4 levels in acute airway samples will be assessed to establish their roles as biomarkers in the time to resolving the exacerbation. This contribution is significant because it is the first step in a continuum of research that is expected to lead to development of pharmacologic strategies that will allow for a patient-individualized management strategy to more quickly restore asthma control and represents a new and substantive departure from the status quo by using a transcellular model to identify in vitro mechanisms, coupled with the infrastructure of the Severe Asthma Research Program and the time-sensitive Asthma Index.