The cell surface glycosphingolipids SSEA-3 and SSEA-4 are not essential for human ESC pluripotency
The cell surface glycosphingolipids SSEA-3 and SSEA-4 are not essential for human ESC pluripotency
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DOI：
10.1634/stemcells.2006-0232
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发表时间：
2007-01-01
期刊：
影响因子：
5.2
通讯作者：
Schulz, Thomas C.
中科院分区：
文献类型：
--
作者：
Brimble, Sandii N.;Sherrer, Eric S.;Schulz, Thomas C.
多能细胞可以从人胚泡中分离出来，并以自我更新、未分化的人 ESC (hESC) 的形式维持在培养物中。这些细胞是人类体外发育的宝贵模型，也是旨在产生用于细胞治疗的分化细胞群的大量研究的焦点。用于表征 hESC 的细胞外标记主要是蛋白聚糖或鞘脂上的碳水化合物表位，例如阶段特异性胚胎抗原 (SSEA)-3 和 -4。 SSEA-3 和 -4 的表达在植入前发育过程中和 hESC 上受到严格调控。尽管这可能意味着未分化细胞中的分子功能，但尚未经过实验测试。我们使用鞘脂和糖鞘脂 (GSL) 生物合成抑制剂来阻断 hESC 中 SSEA-3 和 -4 的生成。使用免疫染色、流式细胞术和串联质谱法证实了这些抗原及其前体的消耗。体外和畸胎瘤中的转录分析、免疫染色和分化表明，多能性的其他特性并未明显受到 GSL 耗竭的影响。这些实验表明，被识别为 SSEA-3 和 -4 的 GSL 在维持 hESC 的多能性方面并不发挥关键的功能作用，而是暗示了此类分子在细胞分化过程中的作用。
Pluripotent cells can be isolated from the human blastocyst and maintained in culture as self-renewing, undifferentiated, human ESCs (hESCs). These cells are a valuable model of human development in vitro and are the focus of substantial research aimed at generating differentiated populations for cellular therapies. The extracellular markers that have been used to characterize hESCs are primarily carbohydrate epitopes on proteoglycans or sphingolipids, such as stage-specific embryonic antigen (SSEA)-3 and -4. The expression of SSEA-3 and -4 is tightly regulated during preimplantation development and on hESCs. Although this might imply a molecular function in undifferentiated cells, it has not yet been tested experimentally. We used inhibitors of sphingolipid and glycosphingolipid (GSL) biosynthesis to block the generation of SSEA-3 and -4 in hESCs. Depletion of these antigens and their precursors was confirmed using immunostaining, flow cytometry, and tandem mass spectroscopy. Transcriptional analysis, immunostaining, and differentiation in vitro and in teratomas indicated that other properties of pluripotency were not noticeably affected by GSL depletion. These experiments demonstrated that the GSLs recognized as SSEA-3 and -4 do not play critical functional roles in maintaining the pluripotency of hESCs, but instead suggested roles for this class of molecules during cellular differentiation.