Yasuda Shin-ya, Tsuneyoshi Norihiro, Sumi Tomoyuki, Hasegawa Kouichi, Tada Takashi, Nakatsuji Norio, Suemori Hirofumi
Department of Development and Differentiation, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Genes Cells. 2006 Sep;11(9):1115-23. doi: 10.1111/j.1365-2443.2006.01000.x.
Nanog is a homeodomain transcription factor that is expressed specifically in undifferentiated embryonic stem (ES) cells and has been shown to be essential in the maintenance of pluripotency in mouse ES cells. To examine the function of NANOG in primate ES cells, we generated transgenic monkey ES cell lines expressing three- to seven-fold higher levels of NANOG protein compared to wild-type ES cells. These NANOG over-expressing cell lines retained their undifferentiated state in the absence of a feeder layer, as shown by expression of undifferentiated ES cell markers such as alkaline phosphatase (ALP) and OCT-4. We also demonstrated that in vitro differentiation of transgenic cell lines was mostly restricted to the ectodermal lineage, as examined by reverse transcriptase-polymerase chain reaction (RT-PCR). Knockdown experiments using NANOG small interfering (si) RNA resulted in induction of differentiation markers such as AFP, GATA4 and GATA6 for the endoderm and CDX2 for the trophectoderm. These results suggest that NANOG plays a crucial role in maintaining the pluripotent state of primate ES cells.
Nanog是一种同源结构域转录因子，在未分化的胚胎干细胞（ES细胞）中特异性表达，并且已被证明在维持小鼠ES细胞的多能性方面至关重要。为了研究NANOG在灵长类ES细胞中的功能，我们生成了转基因猴ES细胞系，这些细胞系中NANOG蛋白的表达水平比野生型ES细胞高3至7倍。如未分化ES细胞标志物碱性磷酸酶（ALP）和OCT-4的表达所示，这些过表达NANOG的细胞系在没有饲养层的情况下保持未分化状态。我们还证明，通过逆转录聚合酶链反应（RT-PCR）检测，转基因细胞系的体外分化大多局限于外胚层谱系。使用NANOG小干扰（si）RNA的敲低实验导致内胚层分化标志物如甲胎蛋白（AFP）、GATA4和GATA6以及滋养外胚层的CDX2的诱导。这些结果表明，NANOG在维持灵长类ES细胞的多能状态中起关键作用。
