Microbial-Derived Lithocholic Acid and Vitamin K₂ Drive the Metabolic Maturation of Pluripotent Stem Cells-Derived and Fetal Hepatocytes

The liver is the main organ responsible for the modification, clearance, and transformational toxicity of most xenobiotics due its abundance in CYP450 enzymes. Human pluripotent stem cells (hPSC) represent an excellent source of differentiated hepatocytes, however, current protocols still produce fetal-like hepatocytes. Interestingly, fetal hepatocytes acquire mature CYP450 expression only post-partum suggesting that nutritional cues may drive hepatic maturation. We show that vitamin K₂ and lithocholic acid, byproduct of intestinal flora, promote the maturation of hPSC-derived and isolated fetal hepatocytes via PXR activation. Analysis of 12 compounds showed a R² correlation of 0.94 between TC₅₀ values obtained in stem cell-derived hepatocytes and primary cells, compared to 0.62 for HepG2 cells. Finally, stem cell-derived hepatocytes demonstrate toxicological end points when exposed to 9 known hepatotoxins. Addition of these cues resulted in the first functional, inducible, hPSC-derived hepatocyte for predictive toxicology.