Targeted metabolomic analysis in hepatic extracts, serum, and urine of female mice gavaged with TCDD every 4 days for 28 days

TCDD is an environmental contaminant that elicits a number of hepatic effects including fat accumulation, inflammation, and fibrosis that can progress to hepatocellular carcinoma. RNA-Seq and targeted metabolomics were integrated with complementary dioxin response element (DRE) location and aryl hydrocarbon receptor (AhR) ChIP-Seq data to further investigate the hepatotoxicity of TCDD. Our integrative analysis identified changes similar to the Warburg effect observed in cancer cells, including pyruvate kinase isoform switching (PKM1 to PKM2), and an increase in the glutaminase (GLS1) GAC:KGA isoform ratio. Consequently, metabolites are redirected towards the pentose phosphate pathway, serine biosynthesis, and glutaminolysis. We propose that the effects of TCDD on central carbon and amino acid metabolism represents AhR-mediated hepatic metabolic reprogramming in order to increase NADPH production as an oxidative stress counter-measure.