The Expression of NF-kB Related Genes in Response to Nanosilver is Cell Type Specific and Related to the Basal Activity of NF-kB
Silver nanoparticles (AgNPs) are widely used in medicine and industry, but the recent evidence for their cytotoxicity rise a concern about the safety of their use. We have previously shown that human HepG2 cells are more vulnerable to AgNPs cytotoxicity, as compared to similarly treated A549 cells. To elaborate the role of the NF-κB signaling pathway in response of A549 and HepG2 cell lines to the treatment with two size of AgNPs (20 nm and 200 nm), we analyzed the expression of 84 key genes related to the NF-κB signaling pathway. We observed considerable alternations in gene expression after treatment of HepG2 with smaller (20 nm) sized AgNPs, but only slight when those cells were exposed to 200 nm AgNPs. We further tested the basal activity and inducibility of the NF-κB pathway using the NF-κB luciferase reporter system and found that those values are negatively correlated - the inducibility of NF-κB signaling in A549 cells is approximately 5 times lower than in HepG2 cells but the basal activity is approximately 3.5 times higher. In accordance a marked activation of the NF-κB pathway after AgNPs treatment was observed in HepG2, but not in A549 Altogether indicate that NF-kB mediated cellular response to AgNPs is cell type specific and related to the basal activity of NF-κB. The work was supported by the Polish Norwegian Research Fund (PNRF-122-AI-1/07) and National Science Centre, decision number DEC-2013/09/B/NZ7/03934.