Transient Expression of Progesterone Receptor Messenger RNA in Ovarian Granuiosa Cells after the Preovulatory Luteinizing Hormone Surge

Abstract

The ovarian steroid progesterone affects reproductive physiology by regulating the expression of specific genes in target tissues. In an attempt to address the question of whether the ovary itself is a target tissue for progesterone action, we have examined the localization and regulation of progesterone receptor (PR) mRNA in the rat ovary. We used the polymerase chain reaction to clone the steroid-binding domain of the rat PR from uterine cDNA and used this as a probe to isolate a larger cDNA from a rat placental cDNA library. We used RNA filter hybridization, a quantitative reverse transcription-polymerase chain reaction amplification assay, and in situ hybridization to detect PR mRNA in the rat ovary. Expression of the PR gene was initially studied in an immature animal model; 23-day-old rats were treated with either PMSG or PMSG followed by hCG. We found little or no PR mRNA in the ovaries of control or PMSG-treated animals; however, the mRNA was highly expressed in the granulosa cells of large follicles in the ovaries of animals treated with PMSG followed by hCG. Other cell types, including thecal and interstitial cells, did not express detectable levels of PR mRNA. The PR mRNA was induced more than 20-fold in the immature ovary 5 h after hCG administration and was down-regulated to near-basal levels by 12 h after hCG administration. In a subsequent series of experiments, we examined PR gene expression in adult rats during the estrous cycle. The expression of PR mRNA was transient and was tightly coupled to the preovulatory LH surge on proestrous evening. PR mRNA was localized to the granulosa cells of mature ovarian follicles during the estrous cycle. In cycling animals treated with pentobarbital to block the preovulatory LH surge, no induction of PR mRNA on proestrous evening was observed. This transient, hormonally regulated, and cell-specific expression of the PR gene in the rat ovary strongly suggests an important intraovarian function for progesterone during the rat reproductive cycle.

Steroid signaling in mature follicles is important for Drosophila ovulation

“…Our study solved this mystery by demonstrating an important role of ecdysteroids, the principal steroid hormones of Drosophila, in mature follicle cells for follicle rupture/ ovulation. Like preovulatory follicles that only transiently up-regulate progesterone receptor in granulosa cells before ovulation (46), mature follicles of Drosophila also adjust their expression of EcR receptors to allow EcR.B2 to remain functioning and promote ovulation. It is interesting that neither progesterone nor ecdysteroid signaling regulates mmp expression (Fig.…”

Identification of androgen, estrogen and progesterone receptor mRNAs in the eye

“…Total RNA was isolated from samples by using modified acid guanidinium-thiocyanatephenol-chloroform extraction procedures (Chomczynski & Sacchi 1987) ) and rat (M20133) ) androgen receptor, hu-man and rabbit (M12674, X03635, M11457) (Fuqua et al 1990;Greene et al 1986aGreene et al , 1986b and rat (Y00102) Koike et al 1987) estrogen receptor, human and rabbit (M15716) Misrahi et al 1987) and rat (S64044) (Park & Mayo 1991) progesterone receptor, and human and rabbit (M10277) (Nakajima-Iijima et al 1985) and rat b-actin (V01217, J00691) (Nudel et al 1983). The PCR conditions and number of cycles, which were selected after communication with Dr. Wilson (androgen receptor), computer analysis (Oligo 4.0 software, National Biosciences; and NCBI BLAST) and extensive experimentation, are shown in Table 2.…”

Expression of two progesterone receptor isoforms in cumulus cells and their roles during meiotic resumption of porcine oocytes

“…However, in granulosa cells, expression of the PR gene is not observed by stimulation with estrogen; the cAMP-protein kinase A (PKA) pathway has been documented to directly activate the distal promoter activity of the PR gene in the cells (Clemens et al 1998). Park and Mayo (1991) reported that PR mRNA was highly expressed in the granulosa cells of large follicles in the ovaries of animals treated with pregnant mare's serum gonadotropin (PMSG) followed by human chorionic gonadotropin (hCG). In in vitro culture of rat granulosa cells, high concentrations of either FSH or LH stimulated PR gene expression (Natraj & Richards 1993).…”