Micropatterned Coculture With 3t3-J2 Fibroblasts Enhances Hepatic Functions And Drug Screening Utility Of Heparg Cells

Human liver models are useful for assessing compound metabolism/toxicity; however, primary human hepatocyte (PHH) lots are limited and highly variable in quality/viability. In contrast, cell lines, such as HepaRG, are cheaper and more reproducible surrogates for initial compound screening; however, hepatic functions and sensitivity for drug outcomes need improvement. Here, we show that HepaRGs cocultured with murine embryonic 3T3-J2 fibroblasts, previously shown to induce PHH functions, could address such limitations. We either micropatterned HepaRGs or seeded them "randomly" onto collagen-coated plates before 3T3-J2 coculture. Micropatterned cocultures (HepaRG-MPCCs) secreted 2- to 4-fold more albumin and displayed more stable cytochrome P450 activities than HepaRG conventional confluent monocultures (HepaRG-CCs) and HepaRG micropatterned hepatocytes (HepaRG-MPHs) for 4weeks, even when excluding dimethyl sulfoxide from the medium. Furthermore, HepaRG-MPCCs had the most albumin-only positive cells (hepatic), lowest cytokeratin 19 (CK19)-only positive cells (cholangiocytic), and highest mean albumin intensity per cell than HepaRG random cocultures and monocultures; however, 80%-84% of HepaRGs remained bipotential (albumin+/CK19+) across all models. The 3T3-J2s also induced higher albumin in HepaRG spheroids than HepaRG-only spheroids. Additionally, although rifampin induced CYP3A4 in HepaRG-MPCCs and HepaRG-CCs, only HepaRG-MPCCs showed the dual omeprazole-mediated CYP1A2/3A4 induction as with PHHs. Lastly, when treated for 6days with 47 drugs and evaluated for albumin and ATP to make binary hepatotoxicity calls, HepaRG-MPCCs displayed a sensitivity of 54% and specificity of 100% (70%/100% in PHH-MPCCs), whereas HepaRG-CCs misclassified several hepatotoxins. Ultimately, HepaRG-MPCCs could be a more cost-effective and reproducible model than PHHs for executing a tier 1 compound screen.