Tomotsune Daihachiro, Hirashima Kanji, Fujii Masako, Yue Fengming, Matsumoto Ken, Takizawa-Shirasawa Sakiko, Yokoyama Tadayuki, Sasaki Katsunori
Department of Biotechnology and Biomedical Engineering, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University Matsumoto, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
PLoS One. 2016 Sep 15;11(9):e0162693. doi: 10.1371/journal.pone.0162693. eCollection 2016.
Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are potential resources for the regeneration of defective organs, including the liver. However, some obstacles must be overcome before this becomes reality. Undifferentiated cells that remain following differentiation have teratoma-forming potential. Additionally, practical applications require a large quantity of differentiated cells, so the differentiation process must be economical. Here we describe a DNA microarray-based global analysis of the gene expression profiles of differentiating human pluripotent stem cells. We identified differences and commonalities among six human pluripotent stem cell lines: the hESCs KhES1, KhES2, KhES3, and H1, and the iPSCs 201B7 and 243G1. Embryoid bodies (EBs) formed without requiring supplementation with inducing factors. EBs also expressed some liver-specific metabolic genes including the ammonia-metabolizing enzymes glutamine synthetase and carbamoyl-phosphate synthase 1. Real-time PCR analysis revealed hepatocyte-like differentiation of EBs treated with ammonia in Lanford medium. Analysis of DNA microarray data suggested that hepatocyte-like cells were the most abundant population in ammonia-treated cells. Furthermore, expression levels of undifferentiated pluripotent stem cell markers were drastically reduced, suggesting a reduced teratoma-forming capacity. These results indicate that treatment of EBs with ammonia in Lanford medium may be an effective inducer of hepatic differentiation in absence of expensive inducing factors.
胚胎干细胞（ESCs）和诱导多能干细胞（iPSCs）是包括肝脏在内的受损器官再生的潜在资源。然而，在这成为现实之前，必须克服一些障碍。分化后残留的未分化细胞具有形成畸胎瘤的潜力。此外，实际应用需要大量的分化细胞，因此分化过程必须经济实惠。在这里，我们描述了基于DNA微阵列对人多能干细胞分化过程中的基因表达谱进行的全局分析。我们确定了六种人多能干细胞系之间的差异和共性：人胚胎干细胞KhES1、KhES2、KhES3和H1，以及诱导多能干细胞201B7和243G1。无需添加诱导因子即可形成胚状体（EBs）。EBs还表达了一些肝脏特异性代谢基因，包括氨代谢酶谷氨酰胺合成酶和氨甲酰磷酸合成酶1。实时PCR分析显示，在兰福德培养基中用氨处理的EBs出现了肝细胞样分化。对DNA微阵列数据的分析表明，肝细胞样细胞是氨处理细胞中最丰富的群体。此外，未分化多能干细胞标志物的表达水平大幅降低，表明形成畸胎瘤的能力下降。这些结果表明，在不使用昂贵诱导因子的情况下，在兰福德培养基中用氨处理EBs可能是肝分化的有效诱导剂。
