Proteomic responses of human intestinal Caco‐2 cells exposed to silver nanoparticles and ionic silver

Abstract

Even although quite a number of studies have been performed so far to demonstrate nanoparticle-specific effects of substances in living systems, clear evidence of these effects is still under debate. The present study was designed as a comparative proteomic analysis of human intestinal cells exposed to a commercial silver nanoparticle reference material and ions from AgNO 3 . A two-dimensional gel electrophoresis/MALDI mass spectrometry (MS)-based proteomic analysis was conducted after 24-h incubation of differentiated Caco-2 cells with non-cytotoxic and low cytotoxic silver concentrations (2.5 and 25 μg ml À1 nanosilver, 0.5 and 5 μg ml À1 AgNO 3 ). Out of an overall number of 316 protein spots differentially expressed at a fold change of ≥ 1.4 or ≤ À1.4 in all treatments, 169 proteins could be identified. In total, 231 spots were specifically deregulated in particle-treated groups compared with 41 spots, which were limited to AgNO 3 -treatments. Forty-four spots (14 %) were commonly deregulated by both types of treatment. A considerable fraction of the proteins differentially expressed after treatment with nanoparticles is related to protein folding, synthesis or modification of proteins as well as cellular assembly and organization. Overlays of networks obtained for particulate and ionic treatments showed matches, indicating common mechanisms of combined particle and ionic silver exposure and exclusive ionic silver treatment. However, proteomic responses of Caco-2 cells treated with higher concentrations of silver species also showed some differences, for example regarding proteins related to fatty acid and energy metabolism, suggesting an induction of also some different molecular mechanisms for particle exposure and ionic treatment.

Mass spectrometry-based proteomics for system-level characterization of biological responses to engineered nanomaterials

“…Proteins involved in key mitochondrial activities, such as electron transfer in the respiratory chain, TCA cycle, and β-oxidation of fatty acid, decreased in abundance upon exposure to ENMs. The down-regulation of mitochondrial enzymes was further confirmed by measuring the membrane potential to indicate the decrease in mitochondrial activity [74,76]. …”

Comparative proteomic analysis of silver nanoparticle effects in human liver and intestinal cells

“…Cells were seeded 24 hours before treatment to reach ~70–80% confluency at the time of treatment. For treatment, cells were incubated for 24 hours with AgPURE silver nanoparticles or ionic silver (AgNO 3 ) as previously described for Caco‐2 cells in (Oberemm et al, ).…”

“…For some analyses, data from a previous publication (Oberemm et al, ) obtained with Caco‐2 human intestinal cells were used. In these previous analyses, Caco‐2 cells were differentiated to a polarized monolayer of small intestinal epithelium‐like cells according to a standard protocol before treatment with the different silver species.…”

“…In rat liver, oxidative stress, inflammation and apoptotic cell death have been reported following intravenous or oral application of silver (Kim et al, ; Patlolla, Hackett, & Tchounwou, ). Consequently, cellular responses to oxidative stress have also been detected by proteomic analyses in vitro (Driessen et al, ; Georgantzopoulou et al, ; Miethling‐Graff et al, ; Oberemm et al, ; Verano‐Braga et al, ). In addition, in vitro effects on cell cycle, proliferation and cancer‐related signaling pathways (Georgantzopoulou et al, ; Huang, Lu, & Ma, ; Oberemm et al, ) as well as on cytoskeletal organization (Georgantzopoulou et al, ; Huang et al, ; Oberemm et al, ) and energy metabolism (Driessen et al, ; Georgantzopoulou et al, ; Oberemm et al, ) have been reported.…”

Interaction between a Broad-spectrum Antibiotic and Silver Nanoparticles in a Human Gut Ecosystem

“…Surface charges associated with some AgNPs preparations may contribute to their toxicity [4]. However, multiple studies have highlighted the critical role of nano-size dependent effects compared to ionic silver, with an emphasis on the unique properties of AgNPs [5][6][7]. Although there are reports of mammalian cell cytotoxicity [8][9][10], these effects are likely relatively minimal at the concentrations used for antimicrobial activity [11].…”