Establishment of bovine trophoblastic cell lines

本研究的目的是从体外受精的胚胎细胞中培养滋养细胞系，以分析牛着床和胎盘发生的机制。在探索这些机制时，滋养细胞系可以提供大量的信息。不幸的是，由于长期培养连续细胞存量的困难，在牛中很少有用于此目的的细胞系。本研究利用骨形态发生蛋白4 （bone morphogenetic protein 4, BMP4）构建了12株新细胞系。这些细胞系维持了大约30代，它们保留了滋养层的特征，并表达了牛滋养层基因：胎盘乳原、干扰素-τ、妊娠相关糖蛋白1和催乳素相关蛋白1。虽然基因表达模式在不同细胞系和不同细胞之间存在差异，但至少有四个特征。均表达牛POU结构域第5类转录因子1和尾型home box 2。通过定量RT-PCR和免疫组化检测证实了这些基因的表达。这些结果表明，BMP4参与了早期胚胎细胞的滋养层细胞系的培养，新发育的细胞系可以提供不同类型、不同细胞系的牛滋养层细胞。这可能成为研究滋养细胞分化的重要新工具。

The purpose of this study is to raise the trophoblastic cell lines from in vitro fertilized embryonic cells for analyzing the mechanism of bovine implantation and placentogenesis. In exploring these mechanisms, trophoblastic cell lines can provide substantial information. Unfortunately, there are few cell lines for this purpose in cattle because of the difficulty of raising successive cell stock in the long term. In this study, 12 new cell lines were established using bone morphogenetic protein 4 (BMP4). These cell lines were maintained for around 30 passages, and they retained trophoblastic characteristics and expressed bovine trophoblastic genes: placental lactogen, interferon-τ, pregnancy-associated glycoprotein 1, and prolactin-related protein 1. Although the gene expression patterns were different among cell lines and depended on the cells, there were at least four characteristics. All of them expressed bovine POU domain class 5 transcription factor 1 and caudal-type home box 2. The expression of these genes was confirmed by quantitative RT-PCR and immunohistochemical detection. These results suggest that BMP4 is involved in the raising of trophoblast cell lines from early embryonic cells and the newly developed cell lines can provide different types of bovine trophoblastic cells with different cell lineages. This may constitute a significant new tool for the examination of trophoblastic differentiation.