Nagaoka Masato, Hagiwara Yuko, Takemura Keiko, Murakami Yuta, Li Jixuan, Duncan Stephen A, Akaike Toshihiro
Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
J Biol Chem. 2008 Sep 26;283(39):26468-76. doi: 10.1074/jbc.M805037200. Epub 2008 Jul 9.
Embryonic stem (ES) cells are pluripotent-undifferentiated cells that have a great interest for the investigation of developmental biology. Murine ES cells maintain their pluripotency by the supplementation of the leukemia inhibitory factor (LIF). LIF is reported to act as a matrix-anchored form, and immobilized cytokines are useful to sustain their signaling on target cells. In this study, we used the immobilizable fusion protein composed of LIF and IgG-Fc region, which was used as a model of the matrix-anchored form of LIF to establish a novel system for ES cell culture and to investigate the effect of immobilized LIF on maintenance of ES cell pluripotency. Mouse ES cells maintained their undifferentiated state on the surface coated with LIF-Fc. Furthermore, when cultured on the co-immobilized surface with LIF-Fc and E-cadherin-Fc, mouse ES cells showed characteristic scattering morphologies without colony formation, and they could maintain their undifferentiated state and pluripotency without additional LIF supplementation. The activation of LIF signaling was sustained on the co-immobilized surface. These results indicate that immobilized LIF and E-cadherin can maintain mouse ES cells efficiently and that the immobilizable LIF-Fc fusion protein is useful for the investigation of signaling pathways of an immobilized form of LIF in the maintenance of ES cell pluripotency.
胚胎干细胞（ES细胞）是多能未分化细胞，在发育生物学研究中备受关注。小鼠ES细胞通过添加白血病抑制因子（LIF）来维持其多能性。据报道，LIF以基质锚定形式发挥作用，固定化细胞因子有助于在靶细胞上维持其信号传导。在本研究中，我们使用了由LIF和IgG-Fc区域组成的可固定化融合蛋白，将其作为LIF的基质锚定形式的模型，以建立一种新型的ES细胞培养系统，并研究固定化LIF对维持ES细胞多能性的影响。小鼠ES细胞在涂有LIF-Fc的表面上维持其未分化状态。此外，当在与LIF-Fc和E-钙黏蛋白-Fc共固定化的表面上培养时，小鼠ES细胞呈现出特征性的散射形态，不形成集落，并且在不额外添加LIF的情况下能够维持其未分化状态和多能性。LIF信号传导在共固定化表面上持续激活。这些结果表明，固定化的LIF和E-钙黏蛋白可以有效地维持小鼠ES细胞，并且可固定化的LIF-Fc融合蛋白对于研究固定化形式的LIF在维持ES细胞多能性中的信号通路是有用的。
