Experimental modeling to identify specific inhalation hazards for nanomaterials has in the main focused on in vivo approaches. However, these models suffer from uncertainties surrounding species-specific differences and cellular targets for biologic response. In terms of pulmonary exposure, approaches which combine ‘inhalation-like’ nanoparticulate aerosol deposition with relevant human cell and tissue air–liquid interface cultures are considered an important complement to in vivo work. In this study, we utilized such a model system to build on previous results from in vivo exposures, which highlighted the small airway epithelium as a target for silver nanoparticle (AgNP) deposition. RNA-SEQ was used to characterize alterations in mRNA and miRNA within the lung. Organotypic-reconstituted 3D human primary small airway epithelial cell cultures (SmallAir) were exposed to the same spark-generated AgNP and at the same dose used in vivo, in an aerosol-exposure air–liquid interface (AE-ALI) system. Adverse effects were characterized using lactate, LDH release and alterations in mRNA and miRNA. Modest toxicological effects were paralleled by significant regulation in gene expression, reflective mainly of specific inflammatory events. Importantly, there was a level of concordance between gene expression changes observed in vitro and in vivo. We also observed a significant correlation between AgNP and mass equivalent silver ion (Ag⁺) induced transcriptional changes in SmallAir cultures. In addition to key mechanistic information relevant for our understanding of the potential health risks associated with AgNP inhalation exposure, this work further highlights the small airway epithelium as an important target for adverse effects.

中文翻译：

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小气道上皮作为吸入银纳米颗粒的不良肺部作用的靶标

识别纳米材料特定吸入危害的实验模型主要集中在体内方法上。但是，这些模型在围绕物种特异性差异和生物反应的细胞靶标方面存在不确定性。就肺部暴露而言，将“吸入样”纳米微粒气溶胶沉积与相关的人体细胞和组织气液界面培养相结合的方法被认为是体内工作的重要补充。在这项研究中，我们利用这样的模型系统来建立体内先前的结果暴露，这突出了小气道上皮作为银纳米颗粒（AgNP）沉积的目标。RNA-SEQ用于表征肺内mRNA和miRNA的变化。在气溶胶暴露气液界面（AE-ALI）系统中，将器官型重构的3D人原发性小气道上皮细胞培养物（SmallAir）暴露于相同的火花生成的AgNP，并以体内使用的相同剂量对其进行暴露。使用乳酸，LDH释放以及m​​RNA和miRNA的改变来表征不良反应。适度的毒理作用与基因表达的显着调节平行，主要反映了特定的炎症事件。重要的是，在体内和体外观察到的基因表达变化之间存在一定程度的一致性。我们还观察到AgNP和质量当量银离子（Ag ⁺）引起SmallAir培养物中转录变化之间的显着相关性。除了与我们了解与AgNP吸入接触有关的潜在健康风险有关的关键机理信息外，这项工作还进一步突出了小气道上皮作为不良反应的重要靶标。