Giannoulias D, Haluska G J, Gravett M G, Sadowsky D W, Challis J R G, Novy M J
Canadian Institutes of Health Research Group in Fetal and Neonatal Health and Development, Department of Physiology, University of Toronto, Toronto, Ontario, Canada.
Placenta. 2005 Apr;26(4):289-97. doi: 10.1016/j.placenta.2004.07.005.
Prostaglandins (PGs) play a central role in primate parturition by their actions on uterine contractility and on cervical ripening. Rhesus monkey placentation is hemochorial and the endocrine events surrounding parturition are qualitatively similar to human pregnancy. Although there is an increase in PG production before the onset of labor, little is known about the cellular localization of the PGH synthase (PGHS) or the 15-hydroxy PG dehydrogenase (PGDH) in the fetal membranes of nonhuman primates and whether it changes at term in spontaneous labor or during preterm labor associated with infection. Placental corticotropin releasing hormone (CRH) and the glucocorticoid receptor (GR) have also been implicated as mediators in parturition by virtue of their roles in PG production. We utilized immunohistochemical methods to localize the inducible isoform PGHS-2, PGDH, GR and CRH in rhesus monkey amnion, chorion and attached decidua. Tissues were obtained at cesarean section during late pregnancy, in spontaneous labor at term and in premature labor induced by Group B streptococcal intraamniotic infection. Specific staining for immunoreactive (ir)-PGHS-2 was observed in amnion epithelial and mesenchymal cells and to a lesser extent in chorion and decidua. In contrast, ir-PGDH was localized primarily to the extravillous trophoblast layer of chorion. GR was localized to both the cytoplasm and nucleus of amnion epithelial cells, subepithelial fibroblasts, chorion trophoblasts and in decidua. Immunostaining for CRH was found in amnion and in scattered decidual cells but was most intense in the chorion trophoblast layer. There was no demonstrable change in this overall pattern of immunostaining in association with the onset of labor at term except for a decrease in staining for ir-PGDH in chorion. Experimental Group B streptococcal chorioamnionitis resulted in preterm labor and extensive necrosis of extravillous trophoblast cells with subsequent loss of chorionic ir-PGDH and relative sparing of ir-PGHS-2 in amnion epithelium which favors the net production of PGs. The expression pattern of these effectors in the rhesus monkey fetal membranes points to a functional role of PGs and glucocorticoids in the process of term and preterm parturition which is similar to that in human pregnancy.
前列腺素（PGs）通过对子宫收缩和宫颈成熟的作用，在灵长类动物分娩中发挥核心作用。恒河猴的胎盘是血绒毛膜型的，分娩前后的内分泌事件在性质上与人类妊娠相似。尽管在分娩开始前PG的产生会增加，但关于非人类灵长类动物胎膜中前列腺素H合成酶（PGHS）或15-羟基前列腺素脱氢酶（PGDH）的细胞定位，以及在足月自然分娩或与感染相关的早产期间其是否发生变化，人们了解甚少。胎盘促肾上腺皮质激素释放激素（CRH）和糖皮质激素受体（GR）也因其在PG产生中的作用而被认为是分娩的介质。我们利用免疫组织化学方法在恒河猴羊膜、绒毛膜和附着的蜕膜中定位诱导型同工型PGHS-2、PGDH、GR和CRH。在妊娠晚期剖宫产时、足月自然分娩时以及由B族链球菌羊膜腔内感染诱导的早产时获取组织。在羊膜上皮和间充质细胞中观察到免疫反应性（ir）-PGHS-2的特异性染色，在绒毛膜和蜕膜中的染色程度较轻。相比之下，ir-PGDH主要定位于绒毛膜的绒毛外滋养层。GR定位于羊膜上皮细胞、上皮下成纤维细胞、绒毛膜滋养层细胞和蜕膜的细胞质和细胞核。在羊膜和散在的蜕膜细胞中发现了CRH的免疫染色，但在绒毛膜滋养层中最为强烈。除了绒毛膜中ir-PGDH的染色减少外，与足月分娩开始相关的这种总体免疫染色模式没有明显变化。实验性B族链球菌绒毛膜羊膜炎导致早产和绒毛外滋养层细胞广泛坏死，随后绒毛膜ir-PGDH丧失，羊膜上皮中的ir-PGHS-2相对保留，这有利于PG的净产生。这些效应物在恒河猴胎膜中的表达模式表明PGs和糖皮质激素在足月和早产分娩过程中发挥功能作用，这与人类妊娠相似。
