University Estadual Paulista, Campus of Dracena, Dracena, Brazil.
PLoS One. 2013 May 28;8(5):e64399. doi: 10.1371/journal.pone.0064399. Print 2013.
To investigate mechanisms of fetal-maternal cell interactions in the bovine placenta, we developed a model of transgenic enhanced Green Fluorescent Protein (t-eGFP) expressing bovine embryos produced by nuclear transfer (NT) to assess the distribution of fetal-derived products in the bovine placenta. In addition, we searched for male specific DNA in the blood of females carrying in vitro produced male embryos. Our hypothesis is that the bovine placenta is more permeable to fetal-derived products than described elsewhere.
METHODOLOGY/PRINCIPAL FINDINGS: Samples of placentomes, chorion, endometrium, maternal peripheral blood leukocytes and blood plasma were collected during early gestation and processed for nested-PCR for eGFP and testis-specific Y-encoded protein (TSPY), western blotting and immunohistochemistry for eGFP detection, as well as transmission electron microscopy to verify the level of interaction between maternal and fetal cells. TSPY and eGFP DNA were present in the blood of cows carrying male pregnancies at day 60 of pregnancy. Protein and mRNA of eGFP were observed in the trophoblast and uterine tissues. In the placentomes, the protein expression was weak in the syncytial regions, but intense in neighboring cells on both sides of the fetal-maternal interface. Ultrastructurally, our samples from t-eGFP expressing NT pregnancies showed to be normal, such as the presence of interdigitating structures between fetal and maternal cells. In addition, channels-like structures were present in the trophoblast cells.
CONCLUSIONS/SIGNIFICANCE: Data suggested that there is a delivery of fetal contents to the maternal system on both systemic and local levels that involved nuclear acids and proteins. It not clear the mechanisms involved in the transfer of fetal-derived molecules to the maternal system. This delivery may occur through nonclassical protein secretion; throughout transtrophoblastic-like channels and/or by apoptotic processes previously described. In conclusion, the bovine synepitheliochorial placenta displays an intimate fetal-maternal interaction, similar to other placental types for instance human and mouse.
为了研究牛胎盘胎儿-母体细胞相互作用的机制，我们开发了一种核移植（NT）生产的表达增强型绿色荧光蛋白（t-eGFP）的转基因牛胚胎模型，以评估胎儿源性产物在牛胎盘的分布。此外，我们还在携带体外生产的雄性胚胎的雌性血液中寻找雄性特异性 DNA。我们的假设是，牛胎盘对胎儿源性产物的通透性比其他地方描述的更高。
方法/主要发现：在妊娠早期收集胎盘、绒毛膜、子宫内膜、母体外周血白细胞和血浆样本，并进行嵌套 PCR 检测 eGFP 和睾丸特异性 Y 编码蛋白（TSPY）、western blot 和免疫组织化学检测 eGFP、透射电镜检测以验证母体和胎儿细胞之间的相互作用水平。携带雄性妊娠的牛在妊娠第 60 天的血液中存在 TSPY 和 eGFP DNA。在滋养层和子宫组织中观察到 eGFP 的蛋白和 mRNA。在胎盘，蛋白表达在合胞体区域较弱，但在胎儿-母体界面两侧的相邻细胞中强烈。超微结构显示，我们来自表达 t-eGFP 的 NT 妊娠的样本正常，例如胎儿和母体细胞之间存在相互交错的结构。此外，滋养层细胞中存在类似通道的结构。
结论/意义：数据表明，胎儿内容物通过系统和局部途径向母体系统传递，涉及核酸和蛋白质。目前尚不清楚将胎儿源性分子转移到母体系统的机制。这种传递可能通过非经典的蛋白质分泌；通过以前描述的跨滋养层样通道和/或通过凋亡过程发生。总之，牛的上皮绒毛膜胎盘表现出与其他胎盘类型（如人类和小鼠）相似的密切的胎儿-母体相互作用。
