Insights into Aflatoxin B1 Toxicity in Cattle: An In Vitro Whole-Transcriptomic Approach

Abstract

<jats:p>Aflatoxins, and particularly aflatoxin B1 (AFB1), are toxic mycotoxins to humans and farm animal species, resulting in acute and chronic toxicities. At present, AFB1 is still considered a global concern with negative impacts on health, the economy, and social life. In farm animals, exposure to AFB1-contaminated feed may cause several untoward effects, liver damage being one of the most devastating ones. In the present study, we assessed in vitro the transcriptional changes caused by AFB1 in a bovine fetal hepatocyte-derived cell line (BFH12). To boost the cellular response to AFB1, cells were pre-treated with the co-planar PCB 3,3′,4,4′,5-pentachlorobiphenyl (PCB126), a known aryl hydrocarbon receptor agonist. Three experimental groups were considered: cells exposed to the vehicle only, to PCB126, and to PCB126 and AFB1. A total of nine RNA-seq libraries (three replicates/group) were constructed and sequenced. The differential expression analysis showed that PCB126 induced only small transcriptional changes. On the contrary, AFB1 deeply affected the cell transcriptome, the majority of significant genes being associated with cancer, cellular damage and apoptosis, inflammation, bioactivation, and detoxification pathways. Investigating mRNA perturbations induced by AFB1 in cattle BFH12 cells will help us to better understand AFB1 toxicodynamics in this susceptible and economically important food-producing species.</jats:p>

Discovering the Protective Effects of Resveratrol on Aflatoxin B1-Induced Toxicity: A Whole Transcriptomic Study in a Bovine Hepatocyte Cell Line

“…The bovine SV40 large T-antigen-transduced foetal hepatocyte-derived cell line BFH12 [ 62 ] was cultured using the experimental procedures detailed in our previously published paper [ 63 ]. Resveratrol (≥99% purity) was obtained from Sigma-Aldrich (St. Louis, MO, USA).…”

“…Resveratrol (≥99% purity) was obtained from Sigma-Aldrich (St. Louis, MO, USA). All chemicals used in the study are commercially available and of molecular biology grade (see details in [ 63 ]). The chemical structure of all the key molecules targeted in the present study (i.e., R, AFB1, AFM1, AFL) has been provided in Figure S1 .…”

“…Then, we assessed the ability of R (10, 20, or 30 μM) to mitigate AFB1-induced cells mortality. In accordance with the approach we followed in our previous studies [ 21 , 63 ], BFH12 cells were pre-treated with an aryl hydrocarbon receptor (AHR) agonist, i.e., PCB126. The rationale of this choice lays on the hypothesis that metabolic competence of foetal hepatocytes may be lower compared to that of adult liver cells.…”

“…To assess the effects of R treatment upon AFB1-induced transcriptional changes, four independent cell culture experiments were conducted. Details about the experimental procedures (i.e., cells incubation, RNA isolation, RNA concentration and quality assessment) are available in our previously published manuscripts [ 21 , 63 ].…”

The Role of Toxic Metals and Metalloids in Nrf2 Signaling

“…Thus, Nrf2 is not only involved in many diseases wherein oxidative stress plays a causal role (e.g., cardiovascular disease, neuronal degeneration, and cancer) [ 22 ] but also functions as a xenobiotic-activated receptor (XAR) to regulate the adaptive response, acting as a powerful protective mechanism for living organisms against exposure to environmental toxicants [ 1 , 7 , 23 ]. Hence, Nrf2 and NFE2L2 are known to be affected by many toxic substances, including aflatoxin B1 [ 24 ], paraquat [ 25 ], phthalates [ 26 ], as well as toxic metals and metaloids such as arsenic [ 27 ], lead [ 28 ], and chromium [ 29 ]. Additionally, As, Pb, and Cr have all been shown to dissociate the Nrf2–Keap1 complex.…”