State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China.
Stem Cells Dev. 2010 Sep;19(9):1427-36. doi: 10.1089/scd.2009.0415.
Liver tissue engineering with hepatic stem cells provides a promising alternative to liver transplantation in patients with acute and chronic hepatic failure. In this study, a three-dimensional (3D) bioscaffold was introduced for differentiation of rat bone marrow mesenchymal stem cells (BMSCs) into hepatocytes. For hepatocyte differentiation, third passage BMSCs isolated from normal adult F344 rats were seeded into collagen-coated poly(lactic-co-glycolic acid) (C-PLGA) 3D scaffolds with hepatocyte differentiation medium for 3 weeks. Hepatogenesis in scaffolds was characterized by reverse transcript PCR, western blot, confocal laser scanning microscopy (CLSM), periodic acid-Schiff staining, histochemistry, and biochemical assays with hepatic-specific genes and markers. A monolayer culture system was used as a control differentiation group. The results showed that isolated cells possessed the basic features of BMSCs. Differentiated hepatocyte-like cells in C-PLGA scaffolds expressed hepatocyte-specific markers [eg, albumin (ALB), alpha-fetoprotein, cytokeratin 18, hepatocyte nuclear factor 4alpha, and cytochrome P450] at mRNA and protein levels. Most markers were expressed in C-PLGA group 1 week earlier than in the control group. Results of biocompatibility indicated that the differentiated hepatocyte-like cells grew more stably in C-PLGA scaffolds than that in controls during a 3-week differentiation period. The significantly higher metabolic functions in hepatocyte-like cells in the C-PLGA scaffold group further demonstrated the important role of the scaffold.
As the phenomenon of transdifferentiation is uncommon, our successful transdifferentiation rates of BMSCs to mature hepatocytes prove the superiority of the C-PLGA scaffold in providing a suitable environment for such a differentiation. This material can possibly be used as a bioscaffold for liver tissue engineering in future clinical therapeutic applications.
利用肝干细胞进行肝组织工程为急性和慢性肝功能衰竭患者的肝移植提供了一种很有前途的替代方法。在这项研究中,引入了一种三维(3D)生物支架,用于将大鼠骨髓间充质干细胞(BMSCs)分化为肝细胞。为了进行肝细胞分化,从正常成年 F344 大鼠中分离的第 3 代 BMSCs 被接种到涂有肝细胞分化培养基的胶原包被的聚(乳酸-共-乙醇酸)(C-PLGA)3D 支架中,培养 3 周。通过逆转录 PCR、western blot、共聚焦激光扫描显微镜(CLSM)、过碘酸-希夫染色、组织化学和生化分析,用肝特异性基因和标志物来鉴定支架中的肝发生情况。单层培养系统用作对照分化组。结果表明,分离的细胞具有 BMSCs 的基本特征。在 C-PLGA 支架中分化的肝样细胞在 mRNA 和蛋白水平上表达了肝特异性标志物[例如白蛋白(ALB)、甲胎蛋白、细胞角蛋白 18、肝核因子 4alpha 和细胞色素 P450]。大多数标志物在 C-PLGA 组中的表达比对照组早 1 周。生物相容性结果表明,在 3 周的分化期间,分化的肝样细胞在 C-PLGA 支架中比在对照中生长更稳定。C-PLGA 支架组中肝样细胞的代谢功能显著提高,进一步证明了支架的重要作用。
由于转分化现象不常见,我们将 BMSCs 成功地转化为成熟肝细胞,证明了 C-PLGA 支架在为这种分化提供合适环境方面的优越性。这种材料将来可能会被用于肝脏组织工程的生物支架,用于临床治疗应用。