Complete and unidirectional conversion of human embryonic stem cells to trophoblast by BMP4
Complete and unidirectional conversion of human embryonic stem cells to trophoblast by BMP4
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DOI：
10.1073/pnas.1303094110
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发表时间：
2013-03-26
影响因子：
11.1
通讯作者：
Ezashi, Toshihiko
中科院分区：
文献类型：
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作者：
Amita, Mitsuyoshi;Adachi, Katsuyuki;Ezashi, Toshihiko
人胚胎干细胞（hESC）暴露于骨形态发生蛋白4（BMP 4）在没有FGF 2的情况下已被广泛用于研究滋养层发育，但该模型的可靠性受到其他人的挑战，他们得出的结论是，分化主要是向中胚层而不是滋养层。在此，我们证实，在标准条件下，在基质胶基质上存在BMP 4且不存在FGF 2的情况下，在由小鼠胚胎成纤维细胞调节的培养基上生长的hESC在48小时内迅速转化为主要为KRT 7（+）的上皮，其中中胚层标记物（包括T（Brachyury））的表达最少。相反，它们开始表达一系列滋养层标志物，包括HLA-G，表现出与培养基中BMP 4的持续存在无关的侵入性特性，并且随着时间的推移，产生大量的人绒毛膜促性腺激素、孕酮、胎盘生长因子和胎盘催乳素。这种分化过程不依赖于小鼠胚胎成纤维细胞对培养基的调节，并且在激活素和FGF 2信号传导抑制剂的存在下加速，其在第2天提供完全为KRT 7（+）的集落，并且其中大多数细胞为瞬时CDX 2（+）。在两种化学成分确定的培养基上生长的集落，包括其中据报道BMP 4驱动中胚层形成的培养基，也响应于BMP 4至少部分地分化为滋养层。实验结果表明，BMP-4/hESC体外培养模型是研究滋养细胞出现和分化的有效模型。
Human ES cells (hESC) exposed to bone morphogenic protein 4 (BMP4) in the absence of FGF2 have become widely used for studying trophoblast development, but the soundness of this model has been challenged by others, who concluded that differentiation was primarily toward mesoderm rather than trophoblast. Here we confirm that hESC grown under the standard conditions on a medium conditioned by mouse embryonic fibroblasts in the presence of BMP4 and absence of FGF2 on a Matrigel substratum rapidly convert to an epithelium that is largely KRT7(+) within 48 h, with minimal expression of mesoderm markers, including T (Brachyury). Instead, they begin to express a series of trophoblast markers, including HLA-G, demonstrate invasive properties that are independent of the continued presence of BMP4 in the medium, and, over time, produce extensive amounts of human chorionic gonadotropin, progesterone, placental growth factor, and placental lactogen. This process of differentiation is not dependent on conditioning of the medium by mouse embryonic fibroblasts and is accelerated in the presence of inhibitors of Activin and FGF2 signaling, which at day 2 provide colonies that are entirely KRT7(+) and in which the majority of cells are transiently CDX2(+). Colonies grown on two chemically defined media, including the one in which BMP4 was reported to drive mesoderm formation, also differentiate at least partially to trophoblast in response to BMP4. The experiments demonstrate that the in vitro BMP4/hESC model is valid for studying the emergence and differentiation of trophoblasts.