Mitani Seiji
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University.
Yakugaku Zasshi. 2019;139(12):1509-1512. doi: 10.1248/yakushi.19-00170.
Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells (iPS-HLCs) are expected to be applicable to large-scale in vitro hepatotoxicity screening systems. Accordingly, methods for generating HLCs from human iPS cells have been improved over the past decade. However, although human hepatocytes have zone-specific characteristics in vivo, there is currently no technique to generate zone-specific HLCs from human iPS cells. Therefore, to generate HLCs with zone-specific properties from human iPS cells, we cultured iPS-HLCs using a parenchymal or nonparenchymal cell-conditioned medium (CM). The results showed that urea production and gluconeogenesis capacity in iPS-HLCs were increased by culturing with cholangiocyte-CM, and glutamine production and drug metabolism capacity in iPS-HLCs were increased by culturing with hepatocyte-CM. It was thus clarified that iPS-HLCs acquire zone 1 hepatocyte-like properties by culturing with cholangiocyte-CM and that iPS-HLCs acquire zone 3 hepatocyte-like properties by culturing with hepatocyte-CM. In addition, we found that WNT inhibitory factor-1 secreted from cholangiocytes, and WNT7B and WNT8B secreted from hepatocytes play important roles in the zone-specific conversion of iPS-HLCs. We hope that our findings will facilitate the application of iPS-HLCs to drug discovery research.
人诱导多能干细胞（iPS）来源的肝样细胞（iPS-HLCs）有望应用于大规模体外肝毒性筛选系统。因此，在过去十年中，从人iPS细胞生成肝样细胞的方法得到了改进。然而，尽管人肝细胞在体内具有区域特异性特征，但目前尚无从人iPS细胞生成区域特异性肝样细胞的技术。因此，为了从人iPS细胞生成具有区域特异性特性的肝样细胞，我们使用实质细胞或非实质细胞条件培养基（CM）培养iPS-HLCs。结果表明，用胆管细胞条件培养基培养可提高iPS-HLCs中的尿素生成和糖异生能力，用肝细胞条件培养基培养可提高iPS-HLCs中的谷氨酰胺生成和药物代谢能力。由此明确，用胆管细胞条件培养基培养可使iPS-HLCs获得1区肝细胞样特性，用肝细胞条件培养基培养可使iPS-HLCs获得3区肝细胞样特性。此外，我们发现胆管细胞分泌的WNT抑制因子-1以及肝细胞分泌的WNT7B和WNT8B在iPS-HLCs的区域特异性转化中起重要作用。我们希望我们的发现将促进iPS-HLCs在药物发现研究中的应用。
