While exposure to diesel exhaust particles has been linked to aberrant immune responses in allergic diseases such as asthma, little attention has been paid to their effects on the airway epithelial barrier. In this study, we sought to determine the effect of diesel exhaust exposure on airway epithelial barrier function and composition using in vitro and in vivo model systems. 16HBE14o- human bronchial epithelial cells were grown on collagen coated Transwell inserts and exposed to 5 to 50 μg/cm2 SRM 2975 diesel particulate matter (DEP) suspended in cell culture medium or vehicle controls. Changes in barrier function were assessed by measuring transepithelial electrical resistance (TEER) and permeability to 4 kDa FITC Dextran. Neonatal BALB/c mice were exposed to aerosolized DEP (255 ± 89 μg/m3; 2 h per day for 5 days) and changes in the tight junction protein Tricellulin were assessed 2 weeks post exposure. A six-hour incubation of epithelial cells with diesel exhaust particles caused a significant concentration-dependent reduction in epithelial barrier integrity as measured by decreased TEER and increased permeability to 4 kDa FITC-Dextran. This reduction in epithelial barrier integrity corresponded to a significant reduction in expression of the tight junction protein Tricellulin. siRNA mediated knockdown of Tricellulin recapitulated changes in barrier function caused by DEP exposure. Neonatal exposure to aerosolized DEP caused a significant reduction in lung Tricellulin 2 weeks post exposure at both the protein and mRNA level. Short term exposure to DEP causes a significant reduction in epithelial barrier integrity through a reduction in the tight junction protein Tricellulin. Neonatal exposure to aerosolized DEP caused a significant and sustained reduction in Tricellulin protein and mRNA in the lung, suggesting that early life exposure to inhaled DEP may cause lasting changes in airway epithelial barrier function.

中文翻译：

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柴油机尾气颗粒暴露会降低上皮紧密连接蛋白三纤维素蛋白的表达


虽然暴露于柴油机尾气颗粒与哮喘等过敏性疾病的异常免疫反应有关，但很少有人关注它们对气道上皮屏障的影响。在这项研究中，我们试图利用体外和体内模型系统确定柴油机尾气暴露对气道上皮屏障功能和组成的影响。 16HBE14o-人支气管上皮细胞在胶原蛋白包被的Transwell插入物上生长，并暴露于悬浮在细胞培养基或载体对照中的5至50μg/cm2 SRM 2975柴油颗粒物质(DEP)。通过测量跨上皮电阻 (TEER) 和 4 kDa FITC 葡聚糖的渗透性来评估屏障功能的变化。新生 BALB/c 小鼠暴露于雾化 DEP（255 ± 89 μg/m3；每天 2 小时，持续 5 天），并在暴露后 2 周评估紧密连接蛋白三纤维素的变化。将上皮细胞与柴油机尾气颗粒一起孵育 6 小时，会导致上皮屏障完整性出现浓度依赖性的显着降低（通过 TEER 降低和 4 kDa FITC-葡聚糖渗透性增加来测量）。上皮屏障完整性的降低与紧密连接蛋白三纤维素蛋白表达的显着降低相对应。 siRNA 介导的三纤维素蛋白敲低再现了 DEP 暴露引起的屏障功能变化。新生儿暴露于雾化 DEP 后 2 周，导致肺三纤维素蛋白的蛋白质和 mRNA 水平显着降低。短期暴露于 DEP 会导致紧密连接蛋白三纤维素蛋白减少，导致上皮屏障完整性显着降低。 新生儿接触雾化 DEP 导致肺部三纤维素蛋白和 mRNA 显着且持续减少，这表明生命早期接触吸入 DEP 可能会导致气道上皮屏障功能发生持久变化。