Expression of the liver-specific gene Cyp7a1 reveals hepatic differentiation in embryoid bodies derived from mouse embryonic stem cells
Expression of the liver-specific gene Cyp7a1 reveals hepatic differentiation in embryoid bodies derived from mouse embryonic stem cells
复制标题
DOI：
10.1111/j.1365-2443.2004.00809.x
复制
发表时间：
2004-12-01
期刊：
影响因子：
2.1
通讯作者：
Teraoka, H
中科院分区：
文献类型：
--
作者：
Asahina, K;Fujimori, H;Teraoka, H
通过肝细胞相关基因如甲胎蛋白和白蛋白的表达，揭示了小鼠胚胎干细胞（ES）通过形成胚状体（EBs）向肝脏分化的过程。然而，众所周知，内脏内胚层在早期EBs中分化并表达这些肝细胞相关基因。因此，目前尚不清楚胚胎干细胞是否能够在体外分化为来自最终内胚层的肝细胞。在本研究中，从胎鼠分离的卵黄囊组织中发现了许多与肝细胞相关的基因。在检测的肝细胞相关基因中，细胞色素P450 7A1 （Cyp7a1）被鉴定为在卵黄囊中不表达的肝脏特异性基因。在EBs发育过程中，Cyp7a1被诱导，与悬浮培养相比，附着培养的EBs更倾向于肝脏分化。白血病抑制因子对培养的EBs内脏内胚层的分化有促进作用，但对原肠胚相关基因的表达和肝脏分化有抑制作用。在Cyp7a1增强子/启动子的控制下，表达绿色荧光蛋白（GFP）的ES细胞显示，培养的EBs中含有GFP阳性的上皮样细胞。这些结果表明胚胎干细胞可以在体外分化为来自最终内胚层的肝细胞。
Hepatic differentiation from mouse embryonic stem (ES) cells via the formation of embryoid bodies (EBs) has been revealed by the expression of hepatocyte-related genes such as alpha-fetoprotein and albumin. It is known, however, that the visceral endoderm differentiates in early EBs and expresses these hepatocyte-related genes. Thus, it remains unclear whether ES cells are capable of differentiating into hepatocytes derived from definitive endoderm in vitro. In the present study, yolk sac tissues isolated from the foetal mouse were found to express many hepatocyte-related genes. Among the hepatocyte-related genes examined, cytochrome P450 7A1 (Cyp7a1) was identified as a liver-specific gene that was not expressed in the yolk sac. Cyp7a1 was induced in developing EBs, and hepatic differentiation was preferentially observed in the developing EBs in attached culture as compared to those in suspension culture. Leukaemia inhibitory factor permitted the differentiation of visceral endoderm, but inhibited the expression of gastrulation-related genes and the hepatic differentiation in cultured EBs. ES cells expressing green fluorescent protein (GFP) under the control of the Cyp7a1 enhancer/promoter showed that cultured EBs contained GFP-positive epithelial-like cells. These results demonstrate that ES cells can differentiate in vitro into hepatocytes derived from definitive endoderm.