Characterization of the role of the cytochrome P450 1A1 in the metabolism of aflatoxin B1 in an engineered (CRISPR-Cas9) bovine liver cell line

Abstract: Aflatoxin B1 (AFB1) is a mycotoxin of particular concern due to its potent hepatotoxic, carcinogenic, and immunosuppressive properties, posing significant risks to human and animal health. In livestock species, exposure to AFB1-contaminated feed may induce several harmful effects, thus representing a major economic and health concern. Cytochrome P450 superfamily is responsible for most of the phase I reactions of endogenous and exogenous compounds, that mainly take place in the liver. These reactions could result in the biotransformation or the bioactivation of xenobiotics. CYP-mediated biotransformation results in less toxic metabolites than the parental compound, whereas in the case of bioactivation, the products are more toxic than the original compound. The main CYPs involved in the metabolism of AFB1 in humans are CYP1A2 and CYP3A4. Despite the susceptibility of bovine to AFB1 hepatotoxicity, little is known about AFB1-liver metabolism in cattle. Which CYPs are involved in the metabolism of AFB1 in bovine, which induce bioactivation and which induce biotransformation of AFB1, which is the mechanism involved? All of these questions are yet to be answered. We used bovine cell line BFH12 in our study. CYP1A2 is present in this cell line, but unlike humans, this CYP is not significantly expressed in bovine. This was the reason; we choose to work on CYP1A1. The CYP1A1 is a member of the cytochrome P450 enzyme superfamily, which plays a crucial role in the oxidative metabolism of various xenobiotic compounds e.g. aflatoxins in bovine species. To better understand the role of CYP1A1 in AFB1 metabolism in bovine liver, in this study, we performed the CRISPR/Cas-9 mediated knockout (KO) of CYP1A1 in BFH12 cells. We used CRISPR/Cas-9 technique to evaluate the role of CYP1A1 in AFB1 metabolism.