Integration of in vitro data from three dimensionally cultured HepaRG cells and physiologically based pharmacokinetic modeling for assessment of acetaminophen hepatotoxicity.

Selection of appropriate fit-for-purpose in vitro and in silico models is critical for non-animal safety assessment of chemical-induced hepatoxicity. The present study evaluated the feasibility of integrating in vitro data from three-dimensionally (3D)-cultured HepaRG cells and physiologically based pharmacokinetic (PBPK) modeling to predict chemical-induced liver toxicity. A 3D organoid culture system was established using an ultralow attachment method. HepaRG cells cultured in a two-dimensional (2D) monolayer and under 3D conditions were exposed to acetaminophen (APAP) at concentrations of 0.16-20 mM. The results showed that the viability of both 3D- and 2D cultured cells was significantly decreased by APAP in a concentration-dependent manner. Furthermore, 3D cultures were more sensitive to APAP-induced mitochondrial damage than 2D cultures were, based on measurements of mitochondrial superoxide accumulation and mitochondrial membrane potential loss. PBPK simulations using nominal in vitro concentrations showed that the APAP concentration eliciting mitochondrial damage was closer to the predicted peak liver concentration in humans in 3D cultures than it was in 2D cultures. In summary, our results suggest that combining in vitro data from 3D HepaRG cultures and PBPK modeling provides a promising tool for assessment of liver injury.