Hepatic cytochrome P450 induction following Kashin-Beck disease-related selenium deficiency and T-2 toxin exposure in mice.

Abstract

Kashin-Beck disease (KBD) is a multifactorial endemic osteoarthropathy that has been associated with nutritional and environmental factors, including selenium deficiency and T-2 toxin exposure. However, whether combined selenium deficiency and T-2 toxin exposure affects hepatic xenobiotic metabolism has not been systematically investigated. Male C57BL/6 mice were fed a selenium-adequate or selenium-deficient diet for 4 weeks, followed by another 4 weeks with or without daily oral T-2 toxin (0.2 mg/kg). Plasma selenium and glutathione peroxidase (GPx) activity were measured. Hepatic histology, activities of major mouse cytochrome P450 (Cyp450) isoforms, and corresponding mRNA and protein expression were assessed. RNA sequencing was performed using liver samples from four biological replicates per group to identify differentially expressed genes (DEGs) and enriched pathways. Selenium deficiency was confirmed by significantly reduced plasma selenium levels and GPx activity. Histological examination revealed marked hepatic steatosis. Transmission electron microscopy further showed prominent ultrastructural alterations including endoplasmic reticulum dilation. The activities of five hepatic Cyp450 isoforms, Cyp1a2, Cyp2b10, Cyp2c29, Cyp2c50, and Cyp3a11, were significantly increased to 1.64-2.51 times the control levels, consistent with increased mRNA and protein expression. Combined selenium deficiency and T-2 toxin exposure was associated with increased hepatic Cyp450 enzyme activity and expression, identifying the liver as a responsive target of KBD-related exposures. These findings suggest the need to further evaluate hepatic xenobiotic metabolism in populations from KBD-endemic areas.