Soluble silver ions from silver nanoparticles induce a polarised secretion of interleukin-8 in differentiated Caco-2 cells

Toxicol Lett. 2020 Jun 1;325:14-24. doi: 10.1016/j.toxlet.2020.02.004. Epub 2020 Feb 13.

Abstract

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 h 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.

Keywords: Caco-2 cells; In vitro; Interleukin-8; Intestinal inflammation; Silver nanoparticles.

MeSH terms

  • Caco-2 Cells
  • Cell Survival / drug effects
  • Colon / drug effects
  • Enteritis / chemically induced
  • Enteritis / pathology
  • Gene Expression / drug effects
  • Humans
  • Inflammation / chemically induced
  • Inflammation / pathology
  • Interleukin-8 / metabolism*
  • Metal Nanoparticles / toxicity*
  • NF-E2-Related Factor 2 / metabolism
  • Oxidative Stress / drug effects
  • Particle Size
  • Silver / toxicity*

Substances

  • CXCL8 protein, human
  • Interleukin-8
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Silver