Hormonal regulation, localization, and functional activity of the progesterone receptor in granulosa cells of rat preovulatory follicles.
Hormonal regulation, localization, and functional activity of the progesterone receptor in granulosa cells of rat preovulatory follicles.
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DOI：
10.1210/endo.133.2.8344215
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发表时间：
1993-08
期刊：
影响因子：
4.8
通讯作者：
U. Natraj;J. Richards
中科院分区：
文献类型：
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作者：
U. Natraj;J. Richards
黄体酮被认为在促黄体生成素诱导排卵和可能的黄体化中起关键作用。本研究旨在探讨促排卵激动剂(促黄体生成素、卵泡刺激素、卵泡刺激素和促性腺激素释放激素)对大鼠排卵前卵泡和体外培养的具有排卵前表型的颗粒细胞孕激素受体(PR)基因和蛋白表达的影响。在培养的颗粒细胞中，黄体生成素以剂量和时间依赖的方式诱导PR基因的表达。大小约为11.0、7.2、6.8、6.2、3.4和3.1千碱基的转录本被排卵期(500 ng/ml)、但不低(50 ng/ml)、黄体生成素和卵泡刺激素浓度以及Forskolin(10微米)、GnRH(1微米)和佛波醇12-肉豆蔻酸盐13-乙酸酯(200 NM)诱导。两种形式的PR蛋白(A和B)也以激动剂和时间依赖的方式被诱导，较短的形式A(摩尔重量，83,000-85,000)比较长的形式B(摩尔重量，115,000)更丰富。间接免疫荧光分析证实了诱导受体的核定位。Forsklin和孕酮，而不是单独的孕酮，能够激活糖皮质激素(孕酮)反应元件-E1b-氯霉素乙酰转移酶报告结构(12倍)。抗孕激素RU486和ZK98299不能抑制PR mRNA和蛋白的诱导，但能有效地阻断糖皮质激素反应元件2-E1b-氯霉素乙酰转移酶激动剂的激活，以及黄体生成素对黄体生成的刺激。这些结果提供了直接证据，表明刺激多种细胞内途径的激动剂可以在颗粒细胞中诱导PR，孕酮在由促黄体生成素激增触发的黄体化过程中发挥作用，并且这种作用至少部分是通过诱导PR来介导的。
Progesterone has been implicated to play a critical role in mediating LH induction of ovulation and possibly luteinization. The present study was undertaken to determine the effects of various agonists (LH, FSH, forskolin, and GnRH) known to stimulate ovulation on their abilities to induce progesterone receptor (PR) mRNA and protein in rat preovulatory follicles and in cultured rat granulosa cells exhibiting a preovulatory phenotype. In cultured granulosa cells, PR mRNA was induced by LH in a dose- and time-dependent manner. Transcripts of approximately 11.0, 7.2, 6.8, 6.2, 3.4, and 3.1 kilobases in size were induced by ovulatory (500 ng/ml), but not low (50 ng/ml), concentrations of LH and FSH as well as by forskolin (10 microM), GnRH (1 microM), and phorbol 12-myristate 13-acetate (200 nM). Two forms (A and B) of PR protein were also induced in an agonist- and time-dependent manner, with the shorter form A (mol wt, 83,000-85,000) appearing in greater abundance than the longer form B (mol wt, 115,000). Indirect immunofluorescent analyses verified nuclear localization of the induced receptor. Forskolin and progesterone, but not progesterone alone, were able to activate a glucocorticoid (progesterone) response element-E1b-chloramphenicol acetyltransferase reporter construct (12-fold) after transfection into cultured granulosa cells. The antiprogestins RU486 and ZK98299 did not inhibit induction of PR mRNA and protein, but effectively blocked agonist activation of glucocorticoid response element2-E1b-chloramphenicol acetyltransferase, as well as LH stimulation of luteinization in vitro. These results provide direct evidence that agonists stimulating diverse intracellular pathways can induce PR in granulosa cells, that progesterone plays a functional role in the luteinization process triggered by the LH surge, and that the effects are mediated at least in part by induction of PR.