Patulin alters alpha-adrenergic receptor signalling and induces epigenetic modifications in the kidneys of C57BL/6 mice.

Patulin (PAT) is a food-borne mycotoxin produced by Penicillium and Byssochlamys species. It is widely known for its mutagenic, carcinogenic, and genotoxic effects and has been associated with kidney injury; however, the mechanism of toxicity remains unclear. To address this gap, we conducted a study to explore the changes in α-adrenergic receptor signalling pathways and epigenetic modifications induced by PAT in the kidneys of C57BL/6 mice during acute (1 day) and prolonged (10 days) exposure. The mice (20-22 g) were orally administered PAT (2.5 mg/kg; at 1 and 10 days), and post-treatment, the kidneys were harvested, homogenised and extracted for RNA, DNA, and protein. The relative gene expression of the α-adrenergic receptors (ADRA1, ADRA2A, ADRA2B) and associated signalling pathways (MAPK, MAPK14, ERK, PI3K, and AKT) was assessed by qPCR. The protein expression of ERK1/2 and MAPK was determined by western blot. The impact of PAT on DNA methylation was evaluated by quantifying global DNA methylation; qPCR was used to determine gene expression levels of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) and demethylase (MBD2). PAT downregulated the expression of ADRA1, ADRA2A, ADRA2B, PI3K, and AKT and upregulated ERK1/2 and MAPK protein expression. Furthermore, PAT induced alterations in DNA methylation patterns by upregulating DNMT1 and MBD2 expressions and downregulating DNMT3A and DNMT3B expressions, resulting in global DNA hypomethylation. In conclusion, PAT disrupts α-1 and α-2 adrenergic receptor signalling pathways and induces epigenetic modifications, that can lead to kidney injury.