Because of their antimicrobial properties, silver nanoparticles are increasingly incorporated in food-related and hygiene products, which thereby could lead to their ingestion. Although their cytotoxicity mediated by oxidative stress has been largely studied, their effects on inflammation remain controversial. Moreover, the involvement of silver ions (originating from Ag0 oxidation) in their mode of action is still unclear. In this context, the present study aims at assessing the impact of silver nanoparticles on the secretion of the pro-inflammatory chemokine interleukin-8 by Caco-2 cells forming an in vitro model of the intestinal mucosal barrier. Silver nanoparticles induced a vectorized secretion of interleukin-8 towards the apical compartment, which is found in the medium 21 hours after the incubation. This secretion seems mediated by Nrf2 signalling pathway that orchestrates cellular defense against oxidative stress. The soluble silver fraction of silver nanoparticles suspensions led to a similar amount of secreted interleukin-8 than silver nanoparticles, suggesting an involvement of silver ions in this interleukin-8 secretion.

中文翻译：

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来自银纳米颗粒的可溶性银离子诱导分化的 Caco-2 细胞中白细胞介素 8 的极化分泌

由于其抗菌特性，银纳米粒子越来越多地被纳入食品相关和卫生产品中，从而可能导致它们被摄入。尽管它们由氧化应激介导的细胞毒性已被大量研究，但它们对炎症的影响仍然存在争议。此外，银离子（源自 Ag0 氧化）在其作用模式中的参与仍不清楚。在此背景下，本研究旨在评估银纳米颗粒对 Caco-2 细胞分泌促炎趋化因子白细胞介素 8 的影响，形成肠粘膜屏障的体外模型。银纳米颗粒诱导了白介素 8 向心尖室的矢量化分泌，这在培养 21 小时后在培养基中发现。这种分泌似乎是由 Nrf2 信号通路介导的，该通路协调细胞对氧化应激的防御。银纳米颗粒悬浮液的可溶性银部分导致分泌的白细胞介素 8 量与银纳米颗粒相似，表明银离子参与了这种白细胞介素 8 的分泌。