Verduzco Adriana, Fecteau Gilles, Lefebvre Réjean, Smith Lawrence C, Murphy Bruce D
Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint Hyacinthe, Québec, J2S 7C6, Canada.
Reprod Fertil Dev. 2012;24(2):392-404. doi: 10.1071/RD10303.
The aim of the present study was to determine the occurrence and localisation of the principal steroidogenic proteins in bovine placenta from Day 50 to Day 120 of pregnancy. Immunohistochemistry revealed that, at all stages investigated, bovine steroidogenic acute regulatory protein (StAR), cytochrome P45011A1 and hydroxy-δ-5-steroid dehydrogenase, 3β- and steroid δ-isomerase 1 proteins were found principally at the fetomaternal interdigitations: the chorionic villus and maternal septum. Moreover, caruncular epithelial cells and uninucleate trophoblast cells were the principal cells detected that were positive for the three markers. Western blot analysis showed that only caruncular tissue expressed all three steroidogenic markers; in contrast, cotyledons only expressed StAR and cytochrome P45011A1. Immunoblot results showed a complementary pattern of StAR and cytochrome P45011A1 expression between caruncles and cotyledons at different stages. These observations suggest that, in early pregnancy, the maternal compartment contributes significantly to bovine placental steroidogenesis, particularly for the synthesis of progesterone. Furthermore, the variation in StAR and cytochrome P45011A1 expression between caruncular and cotyledonary tissues across gestation suggests that placental steroidogenesis requires cell-to-cell communication between maternal and fetal cells.
本研究的目的是确定妊娠第50天至第120天牛胎盘主要类固醇生成蛋白的出现情况和定位。免疫组织化学显示，在所有研究阶段，牛类固醇生成急性调节蛋白（StAR）、细胞色素P45011A1和羟基-δ-5-类固醇脱氢酶、3β-和类固醇δ-异构酶1蛋白主要存在于母胎交错区：绒毛膜绒毛和母体隔膜。此外，肉阜上皮细胞和单核滋养层细胞是检测到的对这三种标志物呈阳性的主要细胞。蛋白质印迹分析表明，只有肉阜组织表达所有三种类固醇生成标志物；相比之下，子叶仅表达StAR和细胞色素P45011A1。免疫印迹结果显示，不同阶段肉阜和子叶之间StAR和细胞色素P45011A1的表达呈互补模式。这些观察结果表明，在妊娠早期，母体部分对牛胎盘类固醇生成有显著贡献，特别是对于孕酮的合成。此外，整个妊娠期肉阜和子叶组织之间StAR和细胞色素P45011A1表达的变化表明，胎盘类固醇生成需要母细胞和胎儿细胞之间的细胞间通讯。
