Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-747, Olsztyn, Poland.
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-747, Olsztyn, Poland.
Theriogenology. 2019 Dec;140:171-179. doi: 10.1016/j.theriogenology.2019.08.028. Epub 2019 Aug 26.
Progesterone (P4) affects cell function through the nuclear progesterone receptor and membrane-bound progesterone binding proteins, including the membrane progestin receptors (mPRs) alpha (mPRα), beta (mPRβ) and gamma (mPRγ), which belong to the progestin and adipoQ receptor family (PAQR7, 8 and 5, respectively). The aim of this study was to determine the mRNA and protein expression levels of mPRα, mPRβ and mPRγ through real-time PCR and Western blot analyses, respectively, and to determine the cellular localization of these proteins in the bovine endometrium and myometrium on days 2-5, 6-10, 11-16 and 17-20 of the oestrous cycle and weeks 3-5, 6-8 and 9-12 of pregnancy (n = 5/each time period). The resulting data showed the highest (P < 0.05) mPRα and mPRβ mRNA expression in the endometrium on days 11-16 of the oestrous cycle compared to the other stages. In the myometrium, the level of mPRα mRNA was the lowest (P < 0.05) on days 6-16 of the oestrous cycle, while mPRβ was the lowest on days 11-16. There were no changes (P > 0.05) in mPRγ mRNA expression in the endometrium and myometrium during the oestrous cycle. During pregnancy, in the endometrium and myometrium, the levels of mPRα and mPRβ mRNA were comparable with those observed during the oestrous cycle. However, mPRγ mRNA expression was the highest (P < 0.001) during all stages of pregnancy compared with that observed during the oestrous cycle in both uterine tissues. The mPRα protein level only changed in the myometrium and was the highest (P < 0.05) during weeks 9-12 of pregnancy. However, in the endometrium, the expression of mPRβ protein was higher (P < 0.05) on days 6-10 of the oestrous cycle than during weeks 6-8 of pregnancy. Strong positive immunoreactions for all mPR proteins were observed in the luminal and glandular epithelium but were less evident in the stromal cells and myocytes. In addition, all proteins were also localized in the endothelial cells of blood vessels in the uterus, suggesting that P4 may affect blood flow in this organ through mPRs. The presence of mPR receptors in the uterus indicates their participation in the regulation of uterine functions.
孕激素（P4）通过核孕激素受体和膜结合孕激素结合蛋白影响细胞功能，包括膜孕激素受体（mPR）α（mPRα）、β（mPRβ）和γ（mPRγ），它们属于孕激素和脂联素受体家族（PAQR7、8 和 5，分别）。本研究旨在通过实时 PCR 和 Western blot 分析分别确定 mPRα、mPRβ 和 mPRγ 的 mRNA 和蛋白表达水平，并确定这些蛋白在牛子宫内膜和子宫肌层中的细胞定位在发情周期的第 2-5、6-10、11-16 和 17-20 天以及妊娠的第 3-5、6-8 和 9-12 周（n=5/每个时间段）。结果数据显示，发情周期第 11-16 天子宫内膜中 mPRα 和 mPRβ mRNA 的表达最高（P<0.05），而其他阶段则较低。在子宫肌层中，mPRα mRNA 的水平在发情周期的第 6-16 天最低（P<0.05），而 mPRβ 在第 11-16 天最低。发情周期期间，子宫内膜和子宫肌层中 mPRγ mRNA 的表达没有变化（P>0.05）。在妊娠期间，子宫内膜和子宫肌层中 mPRα 和 mPRβ mRNA 的水平与发情周期相似。然而，与发情周期相比，在整个妊娠阶段，mPRγ mRNA 的表达最高（P<0.001）。mPRα 蛋白水平仅在子宫肌层发生变化，在妊娠第 9-12 周最高（P<0.05）。然而，在子宫内膜中，发情周期第 6-10 天 mPRβ 蛋白的表达更高（P<0.05），而在妊娠第 6-8 周则较低。所有 mPR 蛋白在腔上皮和腺上皮中均有强烈的阳性免疫反应，但在基质细胞和肌细胞中则不明显。此外，所有蛋白质也定位于子宫血管的内皮细胞中，表明 P4 可能通过 mPR 影响该器官的血流。子宫中存在 mPR 受体表明它们参与了子宫功能的调节。
