In Vitro Three-Dimensional Human Liver Model for Drug-Induced Liver and Bile Duct Injury Prediction.

In drug-induced liver injury (DILI) prediction field, animal models and in vitro cell models are most commonly used. However, animal models require long experimental timelines and may exhibit species-specific differences compared with humans, whereas conventional two-dimensional (2D) cell culture models lack cell-to-cell and cell-to-extracellular matrix (ECM) interaction. Liver organoid models and liver organ-on-a-chip can better simulate the human liver microenvironment; however, the construction of liver organoids requires a long cycle and high costs, while liver organ-on-a-chip systems demand specialized equipment and professional technicians. Herein, we selected the human C3A cell line, characterized by its low cost and facile culture conditions to establish an in vitro three-dimensional (3D) liver model. Briefly, C3A cells were embedded in Matrigel and cultured for 7 days to allow model maturation. Compared with their 2D-cultured cell model, the established 3D model exhibited elevated mRNA expression levels of drug-metabolizing cytochrome P450 enzymes (CYPs). Moreover, the model displayed robust expression of key hepatic biomarkers, as well as bile duct biomarkers. To evaluate the model's applicability for DILI prediction, we performed toxicity assessments using a panel of six well-characterized hepatotoxicants and three non-hepatotoxic compounds. Notably, the 3D C3A model achieved a sensitivity of 83.3%, specificity of 100%, and overall accuracy of 88.9%. Furthermore, treatment of this model with chlorpromazine, a well-characterized cholangiotoxic agent, resulted in suppressed expression of the bile duct biomarker cytokeratin 19 (CK19) and bile salt export pump (BSEP), accompanied by impaired bile acid transport capacity. Taken together, this study provided a simple, low-cost, easy to culture, and more readily scalable 3D hepatic model in comparison with conventional 2D primary human hepatocyte (PHHs) models and other advanced 3D liver models. Notably, the model displayed dual hepatic and biliary characteristics, supporting predictions of both DILI and drug-induced bile duct injury. It provided a promising in vitro platform for assessing drug-induced hepatobiliary toxicity, with potential to reduce reliance on animal experiments and accelerate early-stage screening of novel pharmaceutical candidates.