Department of Bioproduction, Graduate School of Bioindustry, Tokyo University of Agriculture, Abashiri, Hokkaido, 099-2493, Japan.
Dairy Cow Group, Daily Research Center, Hokkaido Research Organization, Nakashibetsu, Hokkaido, 086-1135, Japan; Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, 598-8531, Japan.
Theriogenology. 2019 Nov;139:1-7. doi: 10.1016/j.theriogenology.2019.07.016. Epub 2019 Jul 20.
The mechanism by which the fetal membrane detaches after parturition in cattle is poorly understood, but the upregulation of placentomal prostaglandin and estrogen synthesis are considered to be important. This study investigated whether enhanced glucocorticoid exposure affected the functional maturation of placentomes at induced parturition. Placentomes were collected immediately after spontaneous (beef; n = 5, dairy; n = 5) or induced parturition in beef and dairy cattle. Parturition was induced conventionally using prostaglandin F2α (beef; n = 7, dairy; n = 6) or dexamethasone (beef; n = 6) or with a combination of triamcinolone acetonide (a long-acting glucocorticoid) and a high dose of betamethasone (TABET treatment, beef; n = 6, dairy; n = 9). Gene expression levels and protein localization in placentomes were analyzed by RT-qPCR and immunohistochemistry, respectively. Compared with the conventional methods, TABET treatment resulted in upregulated PTGS2 expression in cotyledons. The expression levels of PTGS2 and PGES were positively correlated in both cotyledons and caruncles. TABET treatment also upregulated the expression of CYP17A1, but not of CYP19A1, in cotyledons. The results revealed, for the first time, that PLA2G4A was localized in microvascular endothelial cells in the cotyledonary villi and the maternal septum. PTGS2 and PGES were colocalized in mononucleated cells of the cotyledonary villi and caruncle epithelial cells adjacent to the chorionic plate. TABET treatment upregulated the expression of placentomal genes involved in PGE2 synthesis and the conversion of pregnenolone to androstenedione. Thus, enhanced glucocorticoid exposure might partially facilitate the functional maturation of placentomes at induced parturition in cattle.
牛胎膜在分娩后分离的机制尚不清楚，但胎盘前列腺素和雌激素合成的上调被认为是重要的。本研究探讨了增强的糖皮质激素暴露是否会影响诱导分娩时胎盘的功能成熟。在牛的自然（肉牛；n=5，奶牛；n=5）或诱导分娩后立即收集胎盘。通过使用前列腺素 F2α（肉牛；n=7，奶牛；n=6）或地塞米松（肉牛；n=6）或曲安西龙（一种长效糖皮质激素）和倍他米松（TABET 治疗，肉牛；n=6，奶牛；n=9）的组合常规诱导分娩。通过 RT-qPCR 和免疫组织化学分别分析胎盘的基因表达水平和蛋白质定位。与传统方法相比，TABET 处理导致绒毛小叶中 PTGS2 的表达上调。PTGS2 和 PGES 的表达水平在绒毛小叶和肉阜中均呈正相关。TABET 处理还上调了绒毛小叶中 CYP17A1 的表达，但不影响 CYP19A1。结果首次表明，PLA2G4A 定位于绒毛小叶和母体隔的微血管内皮细胞中。PTGS2 和 PGES 共定位在绒毛小叶和靠近绒毛板的肉阜上皮细胞的单核细胞中。TABET 处理上调了与 PGE2 合成和孕烯醇酮转化为雄烯二酮相关的胎盘基因的表达。因此，增强的糖皮质激素暴露可能部分促进了牛诱导分娩时胎盘的功能成熟。
