Project description:Transcriptomic changes induced by silver nanoparticles (AgNPs) during spontaneous differentiation of mouse embryonic stem cells (ESCs) were characterized and compared to those induced by Ag+ under otherwise identical conditions. C57BL/6 mESCs were allowed to differentiate after embryoid body (EB) formation and were exposed to 5.0 µg/ml 20 nm AgNPs or 5.0 µg/ml Ag+ for 24 h.
Project description:Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk- and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24h of exposure, but with a recovery at 48h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24h, but not at 48h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms.
Project description:Chlamydomonas reinhardtii exposed to various concentrations of silver For this experiment,C. reinhardtii were exposed to (4) different concentrations of silver, as biological triplicates
