A simplified 3D liver microsphere tissue culture model for hepatic cell signaling and drug-induced hepatotoxicity studies

Although a number of experimental models have been developed for liver research, each has its own advantages and disadvantages. The present study attempted to develop a simple and effective 3-dimensional mouse liver microsphere tissue culture (LMTC) model in vitro for the analysis of hepatic functions. Hepatic characteristics and potential applications of this model were compared with that of mouse model in vivo and mouse primary hepatocytes in vitro. Using freshly-perfused mouse liver tissue passed through 80-mesh sift strainer (sift80), it was demonstrated that under the optimal culture conditions, the sift80 microsphere tissue cultured in 2% bovine calf serum medium remained viable with marked proliferating cell nuclear antigen and anti-Myc proto-oncogene protein expression, exhibited normal hepatic functions including indocyanine green (ICG) uptake/release and periodic acid-Schiff staining, and expressed hepatocyte-specific genes for up to 2 weeks. The microsphere tissue was responsive to bone morphogenic protein 9 (BMP9) stimulation leading to upregulation of downstream targets of BMP9 signaling. Furthermore, 3 commonly-used liver-damaging drugs were indicated to effectively inhibit hepatic ICG uptake, and induce the expression of hepatotoxicity-associated genes. Therefore, this simplified LMTC model may be a useful in vitro tissue culture model to investigate drug-induced liver injury and metabolism, and hepatocyte-based cell singling.