EpCAM Intracellular Domain Promotes Porcine Cell Reprogramming by Upregulation of Pluripotent Gene Expression via Beta-catenin Signaling.
EpCAM Intracellular Domain Promotes Porcine Cell Reprogramming by Upregulation of Pluripotent Gene Expression via Beta-catenin Signaling.
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EpCAM 胞内结构域通过 β-连环蛋白信号传导上调多能基因表达来促进猪细胞重编程
DOI：
10.1038/srep46315
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发表时间：
2017-04-10
影响因子：
4.6
通讯作者：
Wang H
中科院分区：
文献类型：
--
作者：
Yu T;Ma Y;Wang H
先前的研究表明，上皮细胞粘附分子（EpCAM）在猪诱导多能干细胞（piPSC）中的表达显著上调。然而，EpCAM的调控机制和下游靶基因尚未得到充分研究。在本研究中，我们发现EpCAM在成纤维细胞中检测不到，但在piPSC中高表达。EpCAM启动子被合子激活因子LIN 28和ESRRB上调，但被母体因子OCT 4和SOX 2抑制。用shRNA敲除EpCAM后，多能基因的表达量显著降低。相反，EpCAM的过表达显著增加了碱性磷酸酶阳性集落的数量，并提高了内源性多能基因的表达。EpCAM作为一种重要的表核因子，通过两步蛋白水解过程释放其胞间结构域（EpICD）。通过抑制剂TAPI-1和DAPT阻断蛋白水解加工可以降低细胞内EpICD的水平，并降低OCT 4、SOX 2、LIN 28和ESRRB的表达。我们注意到，仅增加细胞内EpICD不能提高EpCAM靶向基因的活性，但是通过阻断GSK-3信号传导和稳定β-catenin信号传导，EpICD可以显著刺激启动子活性。这些结果表明EpCAM胞内结构域需要β-连环蛋白信号传导来增强猪细胞重编程。
Previous study showed that expression of epithelial cell adhesion molecule (EpCAM) was significantly upregulated in porcine induced pluripotent stem cells (piPSCs). However, the regulatory mechanism and the downstream target genes of EpCAM were not well investigated. In this study, we found thatEpCAMwas undetectable in fibroblasts, but highly expressed in piPSCs. Promoter ofEpCAMwas upregulated by zygotic activated factors LIN28, and ESRRB, but repressed by maternal factors OCT4 and SOX2. Knocking downEpCAMby shRNA significantly reduced the pluripotent gene expression. Conversely, overexpression of EpCAM significantly increased the number of alkaline phosphatase positive colonies and elevated the expression of endogenous pluripotent genes. As a key surface-to-nucleus factor, EpCAM releases its intercellular domain (EpICD) by a two-step proteolytic processing sequentially. Blocking the proteolytic processing by inhibitors TAPI-1 and DAPT could reduce the intracellular level of EpICD and lower expressions of OCT4, SOX2, LIN28, and ESRRB. We noticed that increasing intracellular EpICD only was unable to improve activity of EpCAM targeted genes, but by blocking GSK-3 signaling and stabilizing beta-catenin signaling, EpICD could then significantly stimulate the promoter activity. These results showed that EpCAM intracellular domain required beta-catenin signaling to enhance porcine cell reprogramming.