Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
Mol Hum Reprod. 2020 Jun 1;26(6):425-440. doi: 10.1093/molehr/gaaa029.
Human placental development during early pregnancy is poorly understood. Many conceptuses are lost at this stage. It is thought that preeclampsia, intrauterine growth restriction and other placental syndromes that manifest later in pregnancy may originate early in placentation. Thus, there is a need for models of early human placental development. Treating human embryonic stem cells (hESCs) with BMP4 (bone morphogenic protein 4) plus A83-01 (ACTIVIN/NODAL signaling inhibitor) and PD173074 (fibroblast growth factor 2 or FGF2 signaling inhibitor) (BAP conditions) induces differentiation to the trophoblast lineage (hESCBAP), but it is not clear which stage of trophoblast differentiation these cells resemble. Here, comparison of the hESCBAP transcriptome to those of trophoblasts from human blastocysts, trophoblast stem cells and placentas collected in the first-third trimester of pregnancy by principal component analysis suggests that hESC after 8 days BAP treatment most resemble first trimester syncytiotrophoblasts. To further test this hypothesis, transcripts were identified that are expressed in hESCBAP but not in cultures of trophoblasts isolated from term placentas. Proteins encoded by four genes, GABRP (gamma-aminobutyric acid type A receptor subunit Pi), WFDC2 (WAP four-disulfide core domain 2), VTCN1 (V-set domain containing T-cell activation inhibitor 1) and ACTC1 (actin alpha cardiac muscle 1), immunolocalized to placentas at 4-9 weeks gestation, and their expression declined with gestational age (R2 = 0.61-0.83). None are present at term. Expression was largely localized to syncytiotrophoblast of both hESCBAP cells and placental material from early pregnancy. WFDC2, VTCN1 and ACTC1 have not previously been described in placenta. These results support the hypothesis that hESCBAP represent human trophoblast analogous to that of early first trimester and are a tool for discovery of factors important to this stage of placentation.
人类早期胎盘发育知之甚少。许多胚胎在此阶段丢失。人们认为，子痫前期、宫内生长受限和其他在妊娠后期表现出的胎盘综合征可能在胎盘形成早期就已经出现。因此，需要建立早期人类胎盘发育模型。用 BMP4（骨形态发生蛋白 4）加 A83-01（激活素/NODAL 信号抑制剂）和 PD173074（成纤维细胞生长因子 2 或 FGF2 信号抑制剂）（BAP 条件）处理人胚胎干细胞（hESCs）可诱导其向滋养层谱系（hESCBAP）分化，但尚不清楚这些细胞类似于滋养层分化的哪个阶段。在这里，通过主成分分析将 hESCBAP 转录组与来自人类囊胚、滋养层干细胞和妊娠第 1-3 个月胎盘的滋养层进行比较，结果表明，BAP 处理 8 天后的 hESC 最类似于妊娠早期的合体滋养层。为了进一步验证这一假设，鉴定了在 hESCBAP 中表达但不在从足月胎盘分离的滋养层培养物中表达的转录本。GABRP（γ-氨基丁酸 A 型受体亚基 Pi）、WFDC2（WAP 四硫键核心域 2）、VTCN1（含 V -set 结构域的 T 细胞激活抑制剂 1）和 ACTC1（肌动蛋白 alpha 心脏肌肉 1）四个基因编码的蛋白质，免疫组化定位在妊娠 4-9 周的胎盘上，其表达随妊娠年龄下降（R2=0.61-0.83）。在足月时不存在。表达主要定位于 hESCBAP 细胞和早期妊娠胎盘材料的合体滋养层。WFDC2、VTCN1 和 ACTC1 以前未在胎盘上描述过。这些结果支持 hESCBAP 代表类似于妊娠早期的人类滋养层的假设，并且是发现对胎盘形成这一阶段重要的因素的工具。
