Interdepartmental Stem Cell Institute Leuven, Catholic University Leuven, Belgium.
J Hepatol. 2011 Jan;54(1):98-107. doi: 10.1016/j.jhep.2010.06.014. Epub 2010 Sep 6.
BACKGROUND & AIMS: Induced pluripotent stem (iPS) cells exert phenotypic and functional characteristics of embryonic stem cells even though the gene expression pattern is not completely identical. Therefore, it is important to develop procedures which are specifically oriented to induce iPS cell differentiation.
In this study, we describe the differentiation of mouse iPS cells to hepatocyte-like cells, following a directed differentiation procedure that mimics embryonic and fetal liver development. The sequential differentiation was monitored by real-time PCR, immunostaining, and functional assays.
By sequential stimulation with cytokines known to play a role in liver development, iPS cells were specified to primitive streak/mesendoderm/definitive endoderm. They were then differentiated into two types of cells: those with hepatoblast features and those with hepatocyte characteristics. Differentiated hepatocyte-like cells showed functional properties of hepatocytes, such as albumin secretion, glycogen storage, urea production, and inducible cytochrome activity. Aside from hepatocyte-like cells, mesodermal cells displaying some characteristics of liver sinusoidal endothelium and stellate cells were also detected.
These data demonstrate that a protocol, modeled on embryonic liver development, can induce hepatic differentiation of mouse iPS cells, generating a population of cells with mature hepatic phenotype.
诱导多能干细胞（iPS 细胞）表现出胚胎干细胞的表型和功能特征，尽管其基因表达模式并不完全相同。因此，开发专门针对诱导 iPS 细胞分化的程序非常重要。
在这项研究中，我们描述了通过模拟胚胎和胎儿肝脏发育的定向分化程序，将小鼠 iPS 细胞分化为肝样细胞。通过实时 PCR、免疫染色和功能测定来监测连续分化。
通过对已知在肝脏发育中起作用的细胞因子进行顺序刺激，iPS 细胞被特化成为原始条纹/中胚层/确定内胚层。然后，它们被分化为两种类型的细胞：具有肝母细胞特征的细胞和具有肝细胞特征的细胞。分化的肝样细胞表现出肝细胞的功能特性，如白蛋白分泌、糖原储存、尿素生成和诱导细胞色素活性。除了肝样细胞外，还检测到具有一些肝窦内皮细胞和星状细胞特征的中胚层细胞。
这些数据表明，基于胚胎肝脏发育的方案可以诱导小鼠 iPS 细胞的肝向分化，产生具有成熟肝表型的细胞群体。
