Ong Shin-Yeu, Dai Hui, Leong Kam W
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Biomaterials. 2006 Aug;27(22):4087-97. doi: 10.1016/j.biomaterials.2006.03.022. Epub 2006 Apr 17.
Extensive cell-cell or cell-matrix interaction in three-dimensional (3D) culture is important for the maintenance of adult hepatocyte function and the maturation of hepatic progenitors. However, although there is significant interest in inducing the transdifferentiation of adult stem cells into the hepatic lineage, very few studies have been conducted in a 3D culture configuration. The aim of this study is to investigate the differentiation of mesenchymal stem cells (MSC) into hepatocytes in a pellet configuration, with or without the presence of small intestinal submucosa (SIS). After 4 weeks of differentiation with growth factors bFGF, HGF, and OsM, we obtained hepatocyte-like cells that expressed a subset of hepatic genes, secreted albumin and urea, stored glycogen, and showed inducible CYP3A4 mRNA levels. When these cells were implanted into livers of hepatectomized rats, they secreted human albumin into the bloodstream. The hepatic differentiation of MSC was faster in cell pellets without SIS. The plausible explanations for this finding may be related to the mass transport issues of the two different pellets and the role of cell-cell contact over cell-matrix interactions. The findings of this study should help in the design of optimal culture configurations for efficient hepatic differentiation of adult stem cells.
在三维（3D）培养中广泛的细胞 - 细胞或细胞 - 基质相互作用对于维持成人肝细胞功能和肝祖细胞的成熟很重要。然而，尽管人们对诱导成体干细胞向肝谱系转分化有着浓厚兴趣，但在3D培养配置下进行的研究却很少。本研究的目的是调查间充质干细胞（MSC）在有无小肠黏膜下层（SIS）存在的情况下，以微球形式向肝细胞的分化情况。在用生长因子bFGF、HGF和OsM进行4周分化后，我们获得了表达一部分肝脏基因、分泌白蛋白和尿素、储存糖原且显示出可诱导的CYP3A4 mRNA水平的类肝细胞。当将这些细胞植入肝切除大鼠的肝脏中时，它们向血液中分泌人白蛋白。在没有SIS的细胞微球中，MSC的肝分化更快。对此发现的合理原因可能与两种不同微球的物质运输问题以及细胞 - 细胞接触相对于细胞 - 基质相互作用的作用有关。本研究结果应有助于设计用于成人干细胞高效肝分化的最佳培养配置。
