Wong Raymond C B, Dottori Mirella, Koh Karen L L, Nguyen Linh T V, Pera Martin F, Pébay Alice
Monash Institute of Medical Research, Laboratory of Embryonic Stem Cell Biology, Australian Stem Cell Centre, Building 75, STRIP Monash University, Wellington Road, Clayton, Vic. 3800, Australia.
Biochem Biophys Res Commun. 2006 May 26;344(1):181-8. doi: 10.1016/j.bbrc.2006.03.127. Epub 2006 Apr 17.
We investigated the gap junctional properties of human embryonic stem cells (hESC) cultivated in a serum-free system using sphingosine-1-phosphate and platelet-derived growth factor (S1P/PDGF). We compared this condition to hESC grown on Matrigel in mouse embryonic fibroblast conditioned medium (MEF-CM) or unconditioned medium (UM). We show that in all culture systems, hESC express connexins 43 and 45. hESC maintained in S1P/PDGF conditions and hESC grown in presence of MEF-CM are coupled through gap junctions while hESC maintained on Matrigel in UM do not exhibit gap junctional intercellular communication. In this latter condition, coupling was retrieved by addition of noggin, suggesting that BMP-like activity in UM inhibits gap junctional communication. Last, our data indicate that the closure of gap junctions by the decoupling agent alpha-glycyrrhetinic acid increases cell apoptosis and inhibits hESC colony growth. Altogether, these results suggest that gap junctions play an important role in hESC maintenance.
我们使用1-磷酸鞘氨醇和血小板衍生生长因子（S1P/PDGF），研究了在无血清系统中培养的人胚胎干细胞（hESC）的间隙连接特性。我们将这种培养条件与在小鼠胚胎成纤维细胞条件培养基（MEF-CM）或无血清培养基（UM）中的基质胶上生长的hESC进行了比较。我们发现，在所有培养系统中，hESC均表达连接蛋白43和45。在S1P/PDGF条件下维持培养的hESC以及在MEF-CM存在下生长的hESC通过间隙连接相互耦联，而在UM中的基质胶上维持培养的hESC则未表现出间隙连接介导的细胞间通讯。在后一种情况下，通过添加头蛋白可恢复耦联，这表明UM中的骨形态发生蛋白（BMP）样活性抑制了间隙连接通讯。最后，我们的数据表明，去耦联剂α-甘草次酸封闭间隙连接会增加细胞凋亡并抑制hESC集落生长。总之，这些结果表明间隙连接在hESC的维持中起重要作用。
