Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong SAR, China.
Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong SAR, China; Shenzhen Key Laboratory of Fertility Regulation, The University of Hong Kong Shenzhen Hospital, Shenzhen, China.
Differentiation. 2019 Jan-Feb;105:33-44. doi: 10.1016/j.diff.2018.12.003. Epub 2018 Dec 19.
Gap junctional intercellular communication (GJIC) is important for maintaining the pluripotency of mouse embryonic stem cells (mESC). However, human ESC (hESC) have a high level of connexin (Cx) molecules with unknown function. In this study, we found that the major Cx molecule, Cx43, was highly expressed in undifferentiated hESC. It was down-regulated upon spontaneously differentiation by embryoid body formation and induced differentiation along ectoderm, mesoderm and extraembryonic lineages, but up-regulated along endoderm differentiation. The knockdown of Cx43 and GJIC had no effect on the maintenance of hESC, as demonstrated by no morphological changes and similar expression levels of pluripotent markers (OCT4, NANOG, SSEA-3 and SSEA-4) and early differentiation markers (KRT8 and KRT18). Meanwhile, Cx43 knock down had no effect on endodermal markers (SOX17, FOXA2 and CXCR4) expression when hESC were differentiating into definitive endoderm lineage. On the contrary, it led to lower levels of mesodermal markers (CD56, CD34 and PDGFR-α) when cells were undergoing mesoderm differentiation. When compared to control, Cx43 knockdown led to higher attachment rate, HCG secretion and cell invasion of the hESC derived trophoblastic cells. Cx43 knockdown also resulted in up-regulated expressions of placental hormone (β-hCG) and implantation related genes (LIFR, CDH5, LEP, PGF, TGFBR2). Our study suggested that Cx43 and GJIC had no effect on the undifferentiated growth of hESC but affected specific lineage differentiation.
缝隙连接细胞间通讯（GJIC）对于维持小鼠胚胎干细胞（mESC）的多能性很重要。然而，人类胚胎干细胞（hESC）具有高水平的连接蛋白（Cx）分子，其功能未知。在这项研究中，我们发现主要的 Cx 分子 Cx43 在未分化的 hESC 中高度表达。它在自发分化形成胚状体和诱导沿着外胚层、中胚层和胚外谱系分化时下调，但在沿着内胚层分化时上调。Cx43 和 GJIC 的敲低对 hESC 的维持没有影响，因为没有形态变化，并且多能标志物（OCT4、NANOG、SSEA-3 和 SSEA-4）和早期分化标志物（KRT8 和 KRT18）的表达水平相似。同时，当 hESC 分化为确定的内胚层谱系时，Cx43 的敲低对内胚层标志物（SOX17、FOXA2 和 CXCR4）的表达没有影响。相反，当细胞进行中胚层分化时，它导致中胚层标志物（CD56、CD34 和 PDGFR-α）的水平降低。与对照组相比，Cx43 敲低导致 hESC 衍生的滋养层细胞的附着率、HCG 分泌和细胞侵袭更高。Cx43 敲低还导致胎盘激素（β-hCG）和植入相关基因（LIFR、CDH5、LEP、PGF、TGFBR2）的表达上调。我们的研究表明，Cx43 和 GJIC 对 hESC 的未分化生长没有影响，但影响特定谱系的分化。
