Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA.
Stem Cells Dev. 2010 Dec;19(12):1923-35. doi: 10.1089/scd.2009.0326. Epub 2010 Oct 12.
Human embryonic stem cells (hESC) require a balance of growth factors and signaling molecules to proliferate and retain pluripotency. Conditioned medium (CM) from a human embryonic germ-cell-derived cell culture, SDEC, was observed to support the growth of hESC on type I collagen (COL I) and on Matrigel (MAT) biomatricies. After 1 month, the population doubling of hESC grown in SDEC CM on COL I was equivalent to that of hESC grown in mouse embryonic fibroblast (MEF) CM on MAT. hESC grown in SDEC CM on COL I expressed OCT4, NANOG, SSEA-4, alkaline phosphatase (AP), and TRA-1-60; retained a normal karyotype; and were capable of forming teratomas. DNA microarray analysis was used to compare the transcriptional profiles of SDEC and the less supportive WI38 and Detroit 551 human cell lines. The mRNA level of secreted frizzled-related protein (sFRP-1), a known antagonist of the WNT/β-catenin signaling pathway, was significantly reduced in SDEC as compared with the other 2 cell lines, whereas the mRNA levels of prostaglandin-endoperoxide synthase 2 (PTGS2 or COX-2) and prostaglandin I₂ synthase (PGIS), two prostaglandin biosynthesis genes, were significantly increased in SDEC. The level of sFRP-1 protein was significantly reduced, and levels of 2 prostaglandins that are downstream products of PTGS2 and PGIS, prostaglandin E₂ and 6-keto-prostaglandin F(1α), were significantly elevated in SDEC CM compared with WI38, Detroit 551, and MEF CM. Further, addition of purified sFRP-1 to SDEC CM reduced the proliferation of hESC grown on COL I as well as MAT in a dose-dependent manner.
人胚胎干细胞（hESC）需要生长因子和信号分子的平衡才能增殖并保持多能性。观察到源自人胚胎生殖细胞的细胞培养物 SDEC 的条件培养基（CM）支持 hESC 在 I 型胶原（COL I）和 Matrigel（MAT）生物基质上的生长。1 个月后，在 COL I 上生长的 SDEC CM 中的 hESC 的群体倍增与在 MAT 上生长的 hESC 在小鼠胚胎成纤维细胞（MEF）CM 中的群体倍增相当。在 COL I 上生长的 SDEC CM 中的 hESC 表达 OCT4、NANOG、SSEA-4、碱性磷酸酶（AP）和 TRA-1-60；保持正常核型；并且能够形成畸胎瘤。使用 DNA 微阵列分析比较 SDEC 与支持性较差的 WI38 和 Detroit 551 人细胞系的转录谱。与其他 2 种细胞系相比，SDEC 中分泌卷曲相关蛋白（sFRP-1）的 mRNA 水平显着降低，sFRP-1 是 WNT/β-catenin 信号通路的已知拮抗剂，而前列腺素内过氧化物合酶 2（PTGS2 或 COX-2）和前列腺素 I₂ 合酶（PGIS）的 mRNA 水平，两种前列腺素生物合成基因，在 SDEC 中显着增加。SDEC 中的 sFRP-1 蛋白水平显着降低，并且 SDEC CM 中 PTGS2 和 PGIS 的下游产物，前列腺素 E₂和 6-酮-前列腺素 F(1α)的两种前列腺素的水平显着升高，与 WI38、Detroit 551 和 MEF CM 相比。此外，纯化的 sFRP-1 添加到 SDEC CM 中以剂量依赖的方式降低 COL I 上以及 MAT 上生长的 hESC 的增殖。
