Kang Eunhye, Kim Ji-Woo, Jo Seongyea, Ryu Ji Hyeon, Noh Haneul, Park Han-Jin, Kim Hyemin
Division of Advanced Predictive Research, Korea Institute of Toxicology, Daejeon, Republic of Korea.
Division of Advanced Predictive Research, Korea Institute of Toxicology, Daejeon, Republic of Korea.
Toxicology. 2025 Nov;517:154209. doi: 10.1016/j.tox.2025.154209. Epub 2025 Jun 2.
Human pluripotent stem cell (hPSC)-derived hepatic models, including 2D hepatocyte-like cells (2D HLCs) and hepatic organoids (HOs), are valuable in vitro models for evaluating the safety and efficacy of drugs. However, 2D HLCs show limited expression and activity of drug-metabolizing enzymes, particularly cytochrome P450 (CYP450), which are involved in detoxification, a major liver function. HOs have more mature properties than 2D HLCs, particularly enhanced CYP450 gene expression. However, the transcriptional regulatory mechanisms that correlate with CYP450 expression in HOs remain unclear. Epigenetic mechanisms, including DNA methylation and histone modification, are essential for controlling gene expression during stem cell differentiation. Here, we identified epigenetic states around transcriptional regulatory regions and compared them with those in primary human hepatocytes. We found that significantly higher CYP450 gene expression in hPSC-derived HOs than in 2D HLCs was strongly associated with decreased DNA methylation and increased enrichment of histone H3 lysine 27 acetylation in their transcriptional regulatory regions. Furthermore, because of the higher expression of nuclear receptor genes, especially constitutive androstane receptor and pregnane X receptor, HOs showed higher NR-mediated induction of CYP3A4, UGT1A1, and MDR1 than 2D HLCs. Therefore, these results suggest that mature epigenetic regulation may have an impact on drug metabolism and toxicity outcomes in hPSC-derived hepatic models and, hence, be used as an indicator of model maturation.
人多能干细胞（hPSC）衍生的肝脏模型，包括二维类肝细胞（2D HLCs）和肝脏类器官（HOs），是评估药物安全性和有效性的有价值的体外模型。然而，2D HLCs的药物代谢酶，特别是参与解毒（一项主要肝功能）的细胞色素P450（CYP450），其表达和活性有限。HOs比2D HLCs具有更成熟的特性，尤其是CYP450基因表达增强。然而，与HOs中CYP450表达相关的转录调控机制仍不清楚。包括DNA甲基化和组蛋白修饰在内的表观遗传机制对于干细胞分化过程中的基因表达调控至关重要。在这里，我们确定了转录调控区域周围的表观遗传状态，并将它们与原代人肝细胞中的表观遗传状态进行了比较。我们发现，hPSC衍生的HOs中CYP450基因表达显著高于2D HLCs，这与它们转录调控区域中DNA甲基化减少和组蛋白H3赖氨酸27乙酰化富集增加密切相关。此外，由于核受体基因，特别是组成型雄甾烷受体和孕烷X受体的表达较高，HOs比2D HLCs表现出更高的核受体介导的CYP3A4、UGT1A1和MDR1诱导。因此，这些结果表明，成熟的表观遗传调控可能会影响hPSC衍生的肝脏模型中的药物代谢和毒性结果，因此可作为模型成熟度的指标。
