Takayama Kazuo
iPS Cell-based Research Project on Hepatic Toxicity and Metabolism, Graduate School of Pharmaceutical Sciences, Osaka University.
Yakugaku Zasshi. 2015;135(10):1141-6. doi: 10.1248/yakushi.15-00194.
Hepatocyte-like cells differentiated from human pluripotent stem cells (such as human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells) are expected to be utilized in drug screening. However, the hepatocyte differentiation efficiency and hepatic functions of hepatocyte-like cells were not sufficient to perform ES/iPS cell-based drug discovery. Therefore, we decided to improve the method of hepatocyte differentiation from human ES/iPS cells. To enhance this hepatocyte differentiation efficiency, hepatocyte-related transcription factors, such as forkhead box protein A2 (FOXA2) and hepatocyte nuclear factor 1 alpha (HNF1α), were overexpressed during the hepatocyte differentiation process. In addition, to enhance the functions of hepatocyte-like cells, these cells were cultured in three dimensional (3D) conditions using a Nanopillar plate. By FOXA2 and HNF1α overexpression, human ES/iPS cells could efficiently (more than 80%) differentiate into albumin-positive hepatocyte-like cells. Various hepatic functions, including albumin secretion and drug metabolism capacities, of the hepatocyte-like cells were significantly enhanced by performing 3D cell culture. These results suggest that the method of hepatocyte differentiation could be improved by using gene transfer and 3D cell culture technologies. We believe that these new hepatocyte-like cells would be useful tools in drug development.
从人多能干细胞（如人胚胎干细胞（ES细胞）和诱导多能干细胞（iPS细胞））分化而来的类肝细胞有望用于药物筛选。然而，类肝细胞的肝细胞分化效率和肝功能不足以开展基于ES/iPS细胞的药物研发。因此，我们决定改进从人ES/iPS细胞分化肝细胞的方法。为提高这种肝细胞分化效率，在肝细胞分化过程中过表达了肝细胞相关转录因子，如叉头框蛋白A2（FOXA2）和肝细胞核因子1α（HNF1α）。此外，为增强类肝细胞的功能，使用纳米柱板在三维（3D）条件下培养这些细胞。通过过表达FOXA2和HNF1α，人ES/iPS细胞可高效（超过80%）分化为白蛋白阳性的类肝细胞。通过进行3D细胞培养，类肝细胞的各种肝功能，包括白蛋白分泌和药物代谢能力，均得到显著增强。这些结果表明，利用基因转移和3D细胞培养技术可改进肝细胞分化方法。我们相信，这些新的类肝细胞将成为药物研发中的有用工具。
