Chronic infection affects gene expression of drug-metabolizing enzymes in mouse liver.

is an intracellular protozoan parasite causing toxoplasmosis, an infectious disease affecting warm-blooded vertebrates worldwide. Many drug-metabolizing enzymes are located in the liver, a major organ of drug metabolism, and their function can be affected by pathogen infection.Using next-generation sequencing (RNA-seq) and quantitative polymerase chain reaction (qPCR), changes in the hepatic expressions of drug-metabolizing enzymes were analysed in mice chronically infected with . The analysis found that, among drug-metabolizing enzymes, 22 genes were upregulated and 28 genes were downregulated (≥1.5-fold); of these 5 and 17 genes, respectively, were cytochromes P450 (Cyp or P450).Subsequent qPCR analysis showed that six P450 genes were upregulated significantly (≥1.5-fold,  < 0.05), namely, , , , , , and , whereas nine P450 genes were downregulated significantly (≥1.5-fold,  < 0.05), namely, , , , , , , , , and .Moreover, metabolic assays in infected mouse liver using typical P450 substrates revealed that midazolam 1'-hydroxylation and testosterone 2-hydroxylation activities decreased significantly (≥1.5-fold,  < 0.05), whereas testosterone 16-hydroxylation activity increased significantly (≥1.5-fold,  < 0.05).Chronic infection affects drug metabolism, at least partly, by altering the gene expressions of drug-metabolizing enzymes, including P450s.