Generation of Colonies of Induced Trophoblast Cells During Standard Reprogramming of Porcine Fibroblasts to Induced Pluripotent Stem Cells
Generation of Colonies of Induced Trophoblast Cells During Standard Reprogramming of Porcine Fibroblasts to Induced Pluripotent Stem Cells
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DOI：
10.1095/biolreprod.111.092809
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发表时间：
2011-10-01
影响因子：
3.6
通讯作者：
Roberts, R. Michael
中科院分区：
文献类型：
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作者：
Ezashi, Toshihiko;Matsuyama, Haruyo;Roberts, R. Michael
用四因子（POU5F1/SOX2/KLF4/MYC）混合载体对猪间充质细胞进行重编程时，部分菌落具有非典型表型，并且比可识别的猪诱导多能干细胞（iPS）细胞菌落出现得更早。在每次传代后的几天内，具有上皮表型的细胞斑块形成凸起的圆顶，特别是在20% O-2条件下。与iPS细胞的基因表达相比，与滋养细胞（TR）谱系出现相关的转录因子基因表达上调，如GATA2、PPARG、MSX2、DLX3、HAND1、GCM1、CDX2、ID2、ELF5、TCFAP2C和TEAD4，以及合成更典型的TR分化产物所需的基因，如类固醇（HSD17B1、CYP11A1和STAR）、妊娠相关糖蛋白（PAG6）和选择性细胞因子（IFND、IFNG和IL1B）。虽然POU5F1相对于iPS细胞下调，但在诱导的TR （iTR）细胞中，它在继续传代过程中并未被沉默。与iPS细胞一样，iTR细胞在延长传代过程中不会衰老，并表现出较高的端粒酶活性。异种移植到免疫缺陷小鼠后，iTR细胞形成非出血性畸胎瘤，主要由表达TR标记的上皮层组成。当在促进胚状体形成的条件下培养时，iTR细胞形成由单一上皮片组成的漂浮球体，其细胞被桥粒样结构侧向系住。综上所述，将猪成纤维细胞重编程为iPS细胞会产生由自我更新的TR细胞群组成的集落，其中可能含有TR干细胞。
During reprogramming of porcine mesenchymal cells with a four-factor (POU5F1/SOX2/KLF4/MYC) mixture of vectors, a fraction of the colonies had an atypical phenotype and arose earlier than the recognizable porcine induced pluripotent stem (iPS) cell colonies. Within days after each passage, patches of cells with an epithelial phenotype formed raised domes, particularly under 20% O-2 conditions. Relative to gene expression of the iPS cells, there was up-regulation of genes for transcription factors associated with trophoblast (TR) lineage emergence, e.g., GATA2, PPARG, MSX2, DLX3, HAND1, GCM1, CDX2, ID2, ELF5, TCFAP2C, and TEAD4 and for genes required for synthesis of products more typical of differentiated TR, such as steroids (HSD17B1, CYP11A1, and STAR), pregnancy-associated glycoproteins (PAG6), and select cytokines (IFND, IFNG, and IL1B). Although POU5F1 was down-regulated relative to that in iPS cells, it was not silenced in the induced TR (iTR) cells over continued passage. Like iPS cells, iTR cells did not senesce on extended passage and displayed high telomerase activity. Upon xenografting into immunodeficient mice, iTR cells formed nonhemorrhagic teratomas composed largely of layers of epithelium expressing TR markers. When cultured under conditions that promoted embryoid body formation, iTR cells formed floating spheres consisting of a single epithelial sheet whose cells were tethered laterally by desmosome-like structures. In conclusion, reprogramming of porcine fibroblasts to iPS cells generates, as a by-product, colonies composed of self-renewing populations of TR cells, possibly containing TR stem cells.