Fant Michael, Weisoly David L, Cocchia Massimo, Huber Reid, Khan Shaista, Lunt Tiffany, Schlessinger David
Department of Pediatrics, University of Texas, Houston Medical School, Houston, Texas 77030, USA.
Mol Reprod Dev. 2002 Dec;63(4):430-6. doi: 10.1002/mrd.10200.
Plac1, a placenta-specific gene, is expressed exclusively by cells of trophoblastic lineage in the mouse, and maps to a region of the X chromosome known to be important in placental growth. These studies were undertaken to define the cellular location of the mRNA for the human orthologue, PLAC1, within the human placenta, and to examine its expression throughout gestation. By Northern analysis, PLAC1 mRNA was detected in term human placenta, migrating as a single 1.7 kb transcript, but in no other fetal or adult tissues tested. Expression was observed throughout gestation, whereas mouse Plac1 is significantly reduced after 12.5 dpc. Using an (35)S-labeled riboprobe, PLAC1 expression was trophoblast-specific at all stages of gestation (8-41 weeks); no expression was seen in cells within the stromal compartment or decidua. Using BeWo choriocarcinoma cells as a trophoblast model, keratinocyte growth factor (KGF) stimulated steady-state PLAC1 mRNA expression approximately twofold by Northern analysis and quantitative real-time PCR. Stimulation was observed only after 24 hr of exposure, suggesting that the stimulatory effect of KGF is secondary to the promotion of trophoblast growth or differentiation. No change in mRNA levels resulted from exposure to insulin-like growth factor II (IGF-II). Trophoblast-specific expression throughout gestation and responsiveness to KGF are consistent with a fundamental role for PLAC1 at the maternal-fetal interface.
Plac1是一种胎盘特异性基因，在小鼠中仅由滋养层谱系的细胞表达，并定位于X染色体上已知对胎盘生长很重要的区域。开展这些研究是为了确定人类同源基因PLAC1的mRNA在人胎盘中的细胞定位，并研究其在整个妊娠期的表达情况。通过Northern印迹分析，在足月人胎盘中检测到PLAC1 mRNA，以单一的1.7 kb转录本形式迁移，但在其他检测的胎儿或成人组织中均未检测到。在整个妊娠期均观察到表达，而小鼠Plac1在胚胎发育12.5天后显著降低。使用（35）S标记的核糖探针，PLAC1在妊娠各阶段（8 - 41周）的表达均为滋养层特异性；在基质隔室或蜕膜内的细胞中未观察到表达。使用BeWo绒毛膜癌细胞作为滋养层模型，通过Northern印迹分析和定量实时PCR，角质形成细胞生长因子（KGF）刺激稳态PLAC1 mRNA表达增加约两倍。仅在暴露24小时后观察到刺激作用，这表明KGF的刺激作用是滋养层生长或分化促进的继发效应。暴露于胰岛素样生长因子II（IGF-II）后mRNA水平无变化。PLAC1在整个妊娠期的滋养层特异性表达以及对KGF的反应性与PLAC1在母胎界面的基本作用一致。
