Department of Gynecology and Obstetrics, Institute for Cellular Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Stem Cells Dev. 2011 Feb;20(2):351-61. doi: 10.1089/scd.2010.0084. Epub 2010 Oct 21.
Human primordial germ cells (PGCs) have proven to be a source of pluripotent stem cells called embryonic germ cells (EGCs). Unlike embryonic stem cells, virtually little is known regarding the factors that regulate EGC survival and maintenance. In mice, the growth factor bone morphogenetic protein 4 (BMP4) has been shown to be required for maintaining mouse embryonic stem cells, and disruptions in this gene lead to defects in mouse PGC specification. Here, we sought to determine whether recombinant human BMP4 could influence EGC derivation and/or human PGC survival. We found that the addition of recombinant BMP4 increased the number of human PGCs after 1 week of culture in a dose-responsive manner. The efficiency of EGC derivation and maintenance in culture was also enhanced by the presence of recombinant BMP4 based on alkaline phosphatase and OCT4 staining. In addition, an antagonist of the BMP4 pathway, Noggin, decreased PGC proliferation and led to an increase in cystic embryoid body formation. Quantitative real-time (qRT)-polymerase chain reaction analyses and immunostaining confirmed that the constituents of the BMP4 pathway were upregulated in EGCs versus PGCs. Downstream activators of the BMP4 pathway such as ID1 and phosphorylated SMADs 1 and 5 were also expressed, suggesting a role of this growth factor in EGC pluripotency.
人类原始生殖细胞（PGCs）已被证明是多能干细胞的来源，称为胚胎生殖细胞（EGCs）。与胚胎干细胞不同，人们对调节 EGC 存活和维持的因素几乎知之甚少。在小鼠中，骨形态发生蛋白 4（BMP4）已被证明是维持小鼠胚胎干细胞所必需的，该基因的破坏导致小鼠 PGC 特化缺陷。在这里，我们试图确定重组人 BMP4 是否可以影响 EGC 的衍生和/或人 PGC 的存活。我们发现，在培养的第 1 周，添加重组 BMP4 以剂量反应的方式增加了人 PGC 的数量。基于碱性磷酸酶和 OCT4 染色，重组 BMP4 的存在也增强了 EGC 的衍生和维持效率。此外，BMP4 途径的拮抗剂 Noggin 减少了 PGC 的增殖，并导致囊胚形成的增加。实时定量（qRT）-聚合酶链反应分析和免疫染色证实，BMP4 途径的成分在 EGC 中上调，而在 PGC 中下调。BMP4 途径的下游激活剂，如 ID1 和磷酸化的 SMADs1 和 5 也被表达，表明该生长因子在 EGC 多能性中发挥作用。
