Abstract
Excessive exposure to N,N-dimethylformamide (DMF) can lead to occupational liver poisoning in workers; however, the underlying mechanism is not fully clarified. The importance of microRNAs (miRNAs) in chemical-induced hepatotoxicity has been demonstrated. To determine whether miRNAs are also involved in DMF-induced hepatotoxicity, we systematically analyzed the miRNA expression profiles in DMF-treated (75 and 150 mm) HL-7702 liver cells and controls by high-throughput sequencing. Among the altered miRNAs, miR-192-5p was the most significantly upregulated in HL-7702 cells after DMF exposure and was involved in DMF-mediated cell apoptosis. By contrast, suppression of miR-192-5p in HL-7702 cells attenuated the apoptosis induced by DMF. Furthermore, the anti-apoptotic gene (NIN1/RPN12 binding protein 1 homolog [NOB1]) was predicted to be a potential miR-192-5p target according to bioinformatics analysis. The direct interaction between miR-192-5p and NOB1 was confirmed by the dual-luciferase activity assay in HEK293FT cells. Overexpression of miR-192-5p efficiently reduced NOB1 mRNA and protein expression in HL-7702 cells. Alteration in NOB1 expression influenced DMF-induced hepatotoxicity by affecting hepatic apoptosis. In addition, the inverse correlation between miR-192-5p expression levels and NOB1 expression was further confirmed in DMF-exposed mouse liver tissue samples. These observations demonstrated that promotion of apoptosis from the suppression of NOB1 by miR-192-5p overexpression was responsible for the DMF-induced hepatotoxicity. This work provides the molecular mechanism at the miRNA level for hepatic apoptosis induced by DMF.