Ishii Kyoko, Yoshida Yoko, Akechi Yuji, Sakabe Tomohiko, Nishio Ren, Ikeda Remina, Terabayashi Kei, Matsumi Yoshiaki, Gonda Kazue, Okamoto Hideharu, Takubo Kazuko, Tajima Fumihito, Tsuchiya Hiroyuki, Hoshikawa Yoshiko, Kurimasa Akihiro, Umezawa Akihiro, Shiota Goshi
Department of Genetic Medicine and Regenerative Therapeutics, Division of Molecular and Genetic Medicine, Graduate School of Medicine, Tottori University, Yonago, Japan.
Hepatology. 2008 Aug;48(2):597-606. doi: 10.1002/hep.22362.
Human bone marrow-derived mesenchymal stem cells (BM-MSCs) are expected to be a potential source of cells for transplantation. Although recent reports have shown that isolated MSCs can differentiate into hepatocytes, the efficiency of differentiation is insufficient for therapeutic application. To circumvent this problem, it is necessary to understand the mechanisms of hepatic differentiation of human BM-MSCs. Hepatocyte nuclear factor 3beta (HNF3beta), a forkhead/winged helix transcription factor, is essential for liver development. In the present study, we established a tetracycline (Tet)-regulated expression system for HNF3beta in UE7T-13 BM-MSCs. HNF3beta expression significantly enhanced expression of albumin, alpha-fetoprotein (AFP), tyrosine amino transferase (TAT) and epithelial cell adhesion molecule (EpCAM) genes. The differentiated cells showed hepatocyte-specific functions including glycogen production and urea secretion. During treatment with the Tet-on system for 8 days, over 80% of UE7T-13 cells turned out to express albumin. Furthermore, the combination of Tet with basic fibroblast growth factor (bFGF) efficiently induced the genes such as albumin and TAT, which are associated with maturity of hepatocytes; however, it suppressed genes such as AFP and EpCAM, which are associated with immaturity of hepatocytes, suggesting that Tet-induced HNF3beta expression sensitizes BM-MSCs to bFGF signals. Finally, the results of the present study suggest that down-regulation of Wnt/beta-catenin signals caused by translocation of beta-catenin to cytoplasmic membrane is associated with hepatic differentiation of human BM-MSCs.
HNF3beta expression induced efficient differentiation of UE7T-13 human BM-MSCs.
人骨髓间充质干细胞（BM-MSCs）有望成为移植细胞的潜在来源。尽管最近的报告显示分离出的间充质干细胞可分化为肝细胞，但分化效率不足以用于治疗应用。为解决这一问题，有必要了解人BM-MSCs肝分化的机制。肝细胞核因子3β（HNF3β）是一种叉头/翼状螺旋转录因子，对肝脏发育至关重要。在本研究中，我们在UE7T-13 BM-MSCs中建立了四环素（Tet）调控的HNF3β表达系统。HNF3β表达显著增强了白蛋白、甲胎蛋白（AFP）、酪氨酸氨基转移酶（TAT）和上皮细胞粘附分子（EpCAM）基因的表达。分化细胞表现出肝细胞特异性功能，包括糖原生成和尿素分泌。在用Tet-on系统处理8天期间，超过80%的UE7T-13细胞表达白蛋白。此外，Tet与碱性成纤维细胞生长因子（bFGF）的组合有效诱导了与肝细胞成熟相关的白蛋白和TAT等基因；然而，它抑制了与肝细胞不成熟相关的AFP和EpCAM等基因，这表明Tet诱导的HNF3β表达使BM-MSCs对bFGF信号敏感。最后，本研究结果表明，β-连环蛋白向细胞质膜易位导致的Wnt/β-连环蛋白信号下调与人BM-MSCs的肝分化有关。
HNF3β表达诱导UE7T-13人BM-MSCs高效分化。
