Department of Medicine and.
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California; and.
Am J Respir Cell Mol Biol. 2019 Nov;61(5):567-574. doi: 10.1165/rcmb.2018-0402OC.
Chronic obstructive pulmonary disease (COPD) is a worldwide threat. Cigarette smoke (CS) exposure causes cardiopulmonary disease and COPD and increases the risk for pulmonary tumors. In addition to poor lung function, patients with COPD are susceptible to bouts of dangerous inflammation triggered by pollutants or infection. These severe inflammatory episodes can lead to additional exacerbations, hospitalization, further deterioration of lung function, and reduced survival. Suitable models of the inflammatory conditions associated with CS, which potentiate the downward spiral in patients with COPD, are lacking, and the underlying mechanisms that trigger exacerbations are not well understood. Although initial CS exposure activates a protective role for vascular endothelial growth factor (VEGF) functions in barrier integrity, chronic exposure depletes the pulmonary VEGF guard function in severe COPD. Thus, we hypothesized that mice with compromised VEGF production and challenged with CS would trigger human-like severe inflammatory progression of COPD. In this model, we discovered that CS exposure promotes an amplified IL-33 cytokine response and severe disease progression. Our -knockout model combined with CS recapitulates severe COPD with an influx of IL-33-expressing macrophages and neutrophils. Normally, IL-33 is quickly inactivated by a post-translational disulfide bond formation. Our results reveal that BAL fluid from the CS-exposed, VEGF-deficient cohort promotes a significantly prolonged lifetime of active proinflammatory IL-33. Taken together, our data demonstrate that with the loss of a VEGF-mediated protective barrier, the CS response switches from a localized danger to an uncontrolled long-term and long-range, amplified, IL-33-mediated inflammatory response that ultimately destroys lung function.
慢性阻塞性肺疾病(COPD)是一种全球性的威胁。香烟烟雾(CS)暴露会导致心肺疾病和 COPD,并增加肺部肿瘤的风险。除了肺功能不佳外,COPD 患者还容易受到污染物或感染引发的危险炎症发作的影响。这些严重的炎症发作可能导致额外的恶化、住院治疗、肺功能进一步恶化和生存时间缩短。目前缺乏与 CS 相关的炎症条件的合适模型,这些模型可以增强 COPD 患者的下降螺旋,并且触发恶化的潜在机制也尚未完全理解。尽管最初的 CS 暴露激活了血管内皮生长因子(VEGF)在屏障完整性中的保护作用,但慢性暴露会耗尽严重 COPD 中肺部 VEGF 的保护功能。因此,我们假设 VEGF 产生受损且受到 CS 挑战的小鼠会引发类似于人类的严重 COPD 炎症进展。在这种模型中,我们发现 CS 暴露会促进 IL-33 细胞因子反应的放大和严重疾病进展。我们的 VEGF 基因敲除模型与 CS 结合可重现严重 COPD,伴有表达 IL-33 的巨噬细胞和中性粒细胞的大量涌入。通常,IL-33 会通过翻译后二硫键形成迅速失活。我们的结果表明,来自 CS 暴露、VEGF 缺陷小鼠的 BAL 液可促进活性促炎 IL-33 的寿命显著延长。总之,我们的数据表明,随着 VEGF 介导的保护屏障的丧失,CS 反应从局部危险转变为不受控制的长期和远程、放大的、IL-33 介导的炎症反应,最终破坏肺功能。