Carrier-Mediated and Energy-Dependent Uptake and Efflux of Deoxynivalenol in Mammalian Cells

Deoxynivalenol (DON) is one of the most abundant mycotoxins and exerts many adverse effects on humans and animals. To date, the transporting mechanism of DON in mammalian cells remains unclear. In this study, the parallel artificial membrane permeability assay (PAMPA), Transwell models and metabolic inhibitors were used to determine the possible transporting mechanisms of DON in Caco-2, MDCK and HepG2 cells. PAMPA and Transwell models showed reduced passive transport and increased intestinal absorption, indicating a carrier-mediated transporting mechanism. Furthermore, higher unidirectional transport of DON was observed in the basolateral-to-apical direction than in the apical-to-basolateral direction, indicating the existence of efflux proteins. Interestingly, DON was accumulated in the nucleus, and no DON was detected in mitochondria, indicating that the nucleus may be the main target organelle of DON. Moreover, the use of various transporter inhibitors in different cells shows that organic anion transporters, organic cation transporters, and organic anion-transporting polypeptides participate in DON uptake, and P-glycoprotein is the major efflux protein. Importantly, DON uptake is strongly inhibited by metabolic inhibitors and is highly dependent on temperature. In summary, carrier-mediated and energy-dependent uptake and efflux mechanisms for DON in mammalian cells are reported, aiding in improving our understanding of its toxicological mechanisms.