Estradiol 17 beta-dehydrogenase 5 is involved in aflatoxin B1 transportation

Numerous studies have focused on the mechanism of aflatoxin B1 (AFB1) metabolism and its carcinogenic mechanism, but how AFB1 is transported into hepatocytes and how it is transferred inside hepatocytes remains unknown. In this study, the AFB1-interacting protein, estradiol 17 beta-dehydrogenase 5 (Akr1c6), was identified with an immobilized affinity chromatography technique and LC-MS/MS. The interaction between Akr1c6 and AFB1 was confirmed with ELISA, and the results showed that Akr1c6 could efficiently bind AFB1. Anti-Akr1c6 polyclonal antibody from rabbit was prepared, and the IC50 values of AFB1 to BRL (normal big rat liver cells) and NRK (normal rat kidney cells) were detected using the MTT assay. It was found that the Akr1c6 expression level in BRL was significantly affected under the IC50 value of AFB1 (P < 0.05), but no obvious expression difference of Akr1c6 was observed in NRK. This suggested that Akr1c6 in liver cells participates in the transportation and/or metabolism of AFB1, and though Akr1c6 was expressed in the kidneys, it did not play a role in AFB1 transportation or metabolism. The conclusions of this study lay a foundation for further exploring the role of AFB1 binding proteins in the toxicology of AFB1 to hepatocytes and the pathway through which AFB1 enters hepatocytes and their nuclei.