Roulier S, Rochette-Egly C, Alsat E, Dufour S, Porquet D, Evain-Brion D
INSERM U427, Faculté des Sciences Pharmaceutiques et Biologiques de Paris, Université René Descartes-Paris V, France.
Mol Cell Endocrinol. 1996 Apr 19;118(1-2):125-35. doi: 10.1016/0303-7207(96)03773-2.
In the present study, the effect of retinoic acid (RA) and epidermal growth factor (EGF) on the functions of human trophoblastic cells in culture were analysed. In these cells, RA potentiated the hCG secretion increase induced by EGF. To gain a better understanding of such a synergistic effect, the expression of retinoic acid receptors (RAR alpha and beta) and retinoid X receptor (RXR alpha) was studied by immunoblotting in RA- and EGF-treated cells. EGF treatment specifically increased the level of RXR alpha protein and RXR alpha transcripts. In parallel, we demonstrated that the choriocarcinoma cells JEG 3, which respond to RA by an increase in hCG secretion, express constitutively high levels of RXR alpha protein. Furthermore, RXR alpha-transfected trophoblastic cells also become RA responsive for hCG secretion. All these data suggest that RXR alpha expression is modulated by EGF, and may be involved in the effect of RA on hCG secretion.
在本研究中，分析了视黄酸（RA）和表皮生长因子（EGF）对培养的人滋养层细胞功能的影响。在这些细胞中，RA增强了EGF诱导的hCG分泌增加。为了更好地理解这种协同作用，通过免疫印迹法研究了视黄酸受体（RARα和β）和类视黄醇X受体（RXRα）在经RA和EGF处理的细胞中的表达。EGF处理特异性地增加了RXRα蛋白和RXRα转录本的水平。同时，我们证明了绒癌细胞JEG 3通过hCG分泌增加对RA作出反应，其组成性地表达高水平的RXRα蛋白。此外，转染了RXRα的滋养层细胞对RA的hCG分泌也有反应。所有这些数据表明，RXRα的表达受EGF调节，并且可能参与RA对hCG分泌的影响。
