Aflatoxin B1 Induces Immunotoxicity through the DNA Methyltransferase-Mediated JAK2/STAT3 Pathway in 3D4/21 Cells

As the most toxic mycotoxin of all of the fungal toxins, aflatoxin B-1 (AFB(1)) has carcinogenesis, heptotoxicity, and immunotoxicity. DNA methylation plays a critical role in gene expression regulation of the pathological process. However, the relationship between DNA methylation and AFB(1)-induced immunotoxicity was not yet reported. Therefore, the objectives of this study were to verify AFB(1)-induced immunotoxicity and investigate the potential role of the DNA methyltransferase (DNMT) family in AFB(1)-induced immunotoxicity and the pathway mechanism in 3D4/21 cells. The results showed that AFB(1) could induce cytotoxicity, apoptosis, pro-inflammatory cytokine expression, DNA damage, and oxidative stress and decrease phagocytotic capacity. Meanwhile, the levels of DNMT1 and DNMT3a were significantly increased in 0.04 and 0.08 mu g/mL AFB(1) compared to the control. Inhibition of DNMT1 and DNMT3a by 5-Aza-2dc could reverse changes of the above parameters. Further, the JAK2/STAT3 pathway was significantly activated in 0.04 mu g/mL AFB(1). Inhibition of p-JAK2 and p-STAT3 by AG490 could alleviate AFB(1)-induced immunotoxicity. Moreover, inhibition of DNMT1 and DNMT3a by 5-Aza-2dc could suppress the phosphorylation of JAK2 and STAT3. Taken together, AFB(1)-induced immunotoxicity is related to the JAK2/STAT3 pathway mediated by DNMTs in 3D4/21 cells.