Honda Arata, Hirose Michiko, Ogura Atsuo
RIKEN Bioresource Center, 3-1-1, Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
Exp Cell Res. 2009 Jul 15;315(12):2033-42. doi: 10.1016/j.yexcr.2009.01.024. Epub 2009 Feb 6.
Recently, we proposed that rabbit embryonic stem (ES) cells can be stable mammalian ES cells and can be a small animal model for human ES cell research. However, the signaling pathways controlling rabbit ES cell pluripotency remain largely unknown. Here we report that bFGF can maintain the undifferentiated status of rabbit ES cells and found that Activin/Nodal signaling through Smad2/3 activation is necessary to maintain the pluripotent status of rabbit ES cells. We further show that in spite of STAT3 in rabbit ES cells, LIF is dispensable for maintenance of undifferentiated status in rabbit ES cells. Although phosphorylation of Janus Kinase signal transducer and activator (JAK/STAT) disappeared after JAK-inhibitor treatment, OCT4 is constantly produced. When rabbit ES cells were cultured for more than 40 passages in the absence of LIF, expression of stem cell markers and teratoma formation were observed. Additionally, treatment with Rho-associated kinase (ROCK) inhibitor, Y27632, to rabbit ES cells significantly enhanced cell growth. These findings suggest that molecular mechanisms underlying rabbit ES cell self-renewal and pluripotency are similar to primate ES cells. Rabbit ES cells may provide a translational research model for the study of human diseases in vitro and applications to transplantation therapy.
最近，我们提出兔胚胎干细胞（ES细胞）可以成为稳定的哺乳动物ES细胞，并且可以作为人类ES细胞研究的小动物模型。然而，控制兔ES细胞多能性的信号通路在很大程度上仍不清楚。在此我们报告，碱性成纤维细胞生长因子（bFGF）可以维持兔ES细胞的未分化状态，并且发现通过激活Smad2/3的激活素/节点信号对于维持兔ES细胞的多能状态是必需的。我们进一步表明，尽管兔ES细胞中有信号转导子和转录激活子3（STAT3），但白血病抑制因子（LIF）对于维持兔ES细胞的未分化状态是可有可无的。虽然在使用Janus激酶抑制剂处理后Janus激酶信号转导子和转录激活子（JAK/STAT）的磷酸化消失，但仍持续产生八聚体结合转录因子4（OCT4）。当兔ES细胞在无LIF的情况下培养超过40代时，观察到干细胞标志物的表达和畸胎瘤形成。此外，用Rho相关激酶（ROCK）抑制剂Y27632处理兔ES细胞可显著促进细胞生长。这些发现表明，兔ES细胞自我更新和多能性的分子机制与灵长类ES细胞相似。兔ES细胞可能为体外研究人类疾病及移植治疗应用提供一个转化研究模型。
