在当前的一项研究中，来自美国费城儿童医院细胞与分子治疗中心的干细胞生物学家Paul J. Gadue博士和同事们利用细胞因子的信号分子操纵ESCs和iPSCs，将它们变成内胚层祖细胞(endodermalprogenitor cell，EPCs)。这些内胚层祖细胞在实验室中拥有几乎无限的生长潜力，在体外培养或者移植到动物时，能够分化为多种细胞类型，其中代表性的细胞是在肝脏、胰腺和肠道中发现的那些细胞。重要的是，未分化的内胚层祖细胞在移植实验中并不形成畸胎瘤。相关研究结果近日发表在美国权威学术期刊《Cell Stem Cell 细胞·干细胞》上。

    在细胞培养物中，研究人员将内胚层祖细胞分化为β细胞，即表达胰岛素的细胞而且类似于在胰腺中发现的那些细胞。当用葡萄糖刺激时，这些工程β细胞能够释放胰岛素，而这种功能恰恰在糖尿病患者中受到损伤或者缺失。除了产生β细胞之外，研究人员也能够诱导内胚层祖细胞发育成肝细胞和肠道细胞。

    利用人多能性干细胞产生内皮层祖细胞，是一项大有希望的研究结果，它将被科学家们用来开发出一种组织替换疗法，比如为糖尿病病人提供β细胞或者为肝病病人提供肝细胞，从而为这些患者带来治愈的曙光。

    推荐原文阅读：

    Cell Stem Cell. 2012 Apr 6;10(4):371-84. doi: 10.1016/j.stem.2012.02.024.

    Self-renewing endodermal progenitor lines generated from human pluripotent stem cells.

    Cheng X, Ying L, Lu L, Galv?o AM, Mills JA, Lin HC, Kotton DN, Shen SS, Nostro MC, Choi JK, Weiss MJ, French DL, Gadue P.

    SourceDepartment of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, PA 19104, USA.

    Abstract

    The use of human pluripotent stem cells for laboratory studies and cell-based therapies is hampered by their tumor-forming potential and limited ability to generate pure populations of differentiated cell types in vitro. To address these issues, we established endodermal progenitor (EP) cell linesfrom human embryonic and induced pluripotent stem cells. Optimized growth conditions were established that allow near unlimited (>10(16)) EP cell self-renewal in which they display a morphology and gene expression pattern characteristic of definitive endoderm. Upon manipulation of their culture conditions in vitro or transplantation into mice, clonally derived EP cells differentiate into numerous endodermal lineages, including monohormonal glucose-responsive pancreatic β-cells, hepatocytes, and intestinal epithelia. Importantly, EP cells are nontumorigenic in vivo. Thus, EP cellsrepresent a powerful tool to study endoderm specification and offer a potentially safe source of endodermal-derived tissues for transplantation .