Abstract
The generation of hepatocytes that are derived from human adipose stem cells (hASCs) represents an alternative to human hepatocytes for individualized therapeutic and pharmaceutical applications. However, the mechanisms facilitating hepatocyte differentiation from hASCs are not well understood. Here, we show that upon exposure to glycogen synthase kinase 3 (GSK3) inhibitors alone, the expression of definitive endoderm specific genes GATA4, FOXA2, and SOX17 in hASCs significantly increased in a manner with activation of Wnt/β-catenin signalling. Down regulation of the β-catenin expression attenuates the effect of GSK3 inhibitors on the induction of these specific genes. The cells induced using GSK3 inhibitors were directed to differentiate synchronously into hepatocyte-like cells (HLCs) after further combinations of soluble factors by a reproducible three-stage method. Moreover, hASC-HLCs induced using GSK3 inhibitors possess low-density lipoprotein uptake, albumin secretion, and glycogen synthesis ability, express important drug-metabolizing cytochrome P450 (CYP450) enzymes, and demonstrate CYP450 activity. Therefore, our findings suggest that activation of Wnt/β-catenin signalling via GSK3 inhibitors in definitive endoderm specification may represent an important mechanism mediating hASCs differentiated to functional hepatocyte. Furthermore, development of similar compounds may be useful for robust, potentially scalable and cost-effective generation of functional hepatocytes for drug screening and predictive toxicology platforms.