miRNA-217 Targets nup43 in Zebrafish in Response to Triazophos Exposure

MicroRNAs (miRNAs), which belong to small noncoding RNAs, can regulate the expression of target gene(s) by mediating mRNA cleavage or by translational repression, especially in organisms exposed to environmental chemicals. We found nup43 is targeted by miR-217, which was significantly regulated in adult zebrafish (Danio rerio) exposed to triazophos (phenyl-1,2,4-triazolyl-3-(o,o-diethyl thionophosphate)). The expression of nup43 was downregulated in mRNA and protein levels in a dose-dependent manner upon stimulation of triazophos. The dual luciferase report assay demonstrated that miR-217 interacted with 3'-untranslated regions (3'-UTR) of nup43. The expression of nup43 was reduced in mRNA and protein levels when ZF4 cells were transfected with miR-217 mimic, whereas mRNA and protein levels were increased when ZF4 cells were transfected with miR-217 inhibitor. As a result, nup43 is targeted by miR-217 upon triazophos exposure. The expression pattern of the miRNA presents novel responses to triazophos, which could be used as a toxicological biomarker.