Comparative Analysis of Transcriptional Profile Changes in Larval Zebrafish Exposed to Zinc Oxide Nanoparticles and Zinc Sulfate.

Many studies of the toxic effects of zinc oxide nanoparticles (ZnO NPs) in aquatic organisms have been performed because of increasing ZnO NP use. However, the toxicological pathways are not understood. In this study, ZnO NPs were found to be more toxic than ZnSO to zebrafish larvae, but ZnO NP toxicity did not involve transcript alterations. Biological processes affected by ZnO NPs and ZnSO were investigated by performing ingenuity pathway analysis on differently expressed genes in larvae exposed to sub-lethal ZnO NP and ZnSO concentrations. We identified upregulated and downregulated differently expressed genes in fish exposed to ZnO NPs and ZnSO, and found that ZnO NPs slightly induced cell differentiation and pathways associated with the immune system and activated several key genes involved in cancer cell signaling. The results may be key to predicting and elucidating the mechanisms involved in ZnO NP and ZnSO toxicity in zebrafish larvae.