scholarly journals Inhibitory effect of retinoic acid on the development of immature porcine granulosa cells to mature cells

2000 ◽  
Vol 25 (1) ◽  
pp. 53-61 ◽  
Author(s):  
M Hattori ◽  
K Takesue ◽  
N Nishida ◽  
Y Kato ◽  
N Fujihara

The present study investigated the effect of retinoic acid (RA) on the differentiation of granulosa cells prepared from porcine ovaries. The granulosa cells were precultured for 15 h, then cultured for 48 h with FSH and further treated for 24 h with LH in order to induce their transformation into luteal cells. After the cells had been exposed to 1 microM retinoids (RA, retinal and retinol) for 87 h, analysis of the LH receptor mRNA expression, an indicator of granulosa cell differentiation, was carried out by using semiquantitative RT-PCR. The results showed that there was a decrease in LH receptor mRNA levels, and that RA had a more potent effect on these levels than the other two retinoids. When cells were exposed to RA in the immature stage (before the addition of FSH) or the early stage of development (0-24 h after the addition of FSH), expression of LH receptor mRNA was greatly diminished. When the immature cells were cultured for 15 h with RA, then washed and cultured for 48 h with FSH and for 24 h with LH, the expression of LH receptor mRNA was not reversed. In the differentiated cells (24 h after the addition of FSH), however, RA no longer had any inhibitory effect. When the immature cells were exposed to RA, FSH-induced expression of c-fos mRNA was markedly decreased. In contrast, expression of c-jun and activating transcription factor-4 mRNAs remained constant. However, the expression of c-fos mRNA was not decreased by forskolin. The results indicate that RA is a potent inhibitor in the immature stage of porcine granulosa cell differentiation, probably through decreased expression of FSH receptor, but that RA does not inhibit differentiation in the mature stage of the cells.

Endocrinology ◽  
2003 ◽  
Vol 144 (9) ◽  
pp. 3985-3994 ◽  
Author(s):  
Anthony J. Zeleznik ◽  
Deeksha Saxena ◽  
Lynda Little-Ihrig

Abstract Although FSH receptors are linked to the cAMP second messenger system, additional intracellular signaling pathways appear to be required for the induction of aromatase and the LH receptor during granulosa cell differentiation. We employed adenovirus vectors to modulate specific intracellular signaling systems in undifferentiated granulosa cells to identify the signaling pathway(s) that may be involved in the FSH-mediated induction of aromatase and the LH receptor. Expression of either the constitutively activated human LH receptor D578H or the constitutively active human Gsα Q227L resulted in increased cAMP production without increasing aromatase activity or mRNA levels for the LH receptor. To explore the contributions of other pathways, we expressed the constitutively activated forms MAPK kinase (MEK) and protein kinase B (PKB). Neither MEK nor PKB alone increased estrogen or progesterone production by undifferentiated granulosa cells. Stimulation of granulosa cells by FSH in the presence of the constitutively active PKB, but not MEK, led to an amplification of FSH-induced aromatase and LH receptor mRNA levels, whereas a dominant negative PKB vector completely abolished the actions of FSH. The expression of the constitutively active PKB in combination with the constitutively active LH receptor D578H, the constitutively active Gsα Q227L, or 8-bromo-cAMP led to an induction of aromatase as well as LH receptor mRNA comparable to that seen in cells stimulated with FSH alone. These results demonstrate that PKB is an essential component of the FSH-mediated granulosa cell differentiation and that both PKB and Gsα signaling pathways are required.


Endocrinology ◽  
2001 ◽  
Vol 142 (7) ◽  
pp. 2742-2751 ◽  
Author(s):  
Kathleen H. Burns ◽  
Changning Yan ◽  
T. Rajendra Kumar ◽  
Martin M. Matzuk

Abstract FSH is a heterodimeric glycoprotein hormone that is produced in the gonadotroph cells of the anterior pituitary. It acts on Sertoli cells of the testis and granulosa cells of the ovary. We previously demonstrated that FSHβ knockout female mice are infertile due to a block in folliculogenesis preceding antral stage development. To investigate aberrations of ovarian gene regulation in the absence of FSH, we analyzed the expression of several important marker genes using Northern blot and in situ hybridization techniques. Key findings are as follows: 1) Follicles of FSHβ knockout mice develop a well organized thecal layer, which is positive for P450 17α-hydroxylase and LH receptor messenger RNAs (mRNAs). This indicates that theca recruitment is completed autonomously with respect to FSH. 2) Granulosa cells in FSH-deficient mice demonstrate an increase in FSH receptor mRNA, and decreases in P450 aromatase, serum/glucocorticoid-induced kinase, and inhibin/activin subunit mRNAs. These data support studies that implicate FSH signaling cascades in the expression of these genes. 3) In contrast to the thecal layer, granulosa cell populations in FSHβ knockout mice do not accumulate LH receptor mRNA. This suggests that although the granulosa cells have a block in proliferation at the antral follicle stage in the absence of FSH, they do not initiate programs of terminal differentiation as seen in luteinizing cells of wild-type ovaries. 4) Ovaries of FSH-deficient mice demonstrate a modest decrease in cyclin D2 mRNA, without up-regulation of cell cycle inhibitor mRNAs associated with luteinization (i.e. p15, p27, and p21). Although components of the FSH null phenotype may be caused by partial cyclin D2 loss of function, these findings indicate that the mechanisms of granulosa cell cycle arrest in FSHβ knockout mice are distinct from those of cycle withdrawal at luteinization. Underscoring the usefulness of the FSH-deficient mouse model, this study clarifies aspects of gonadotropin-dependent folliculogenesis, thecal layer development, cycle control in granulosa cells, and luteinization.


1998 ◽  
Vol 83 (2) ◽  
pp. 448-452
Author(s):  
H. F. Erden ◽  
I. H. Zwain ◽  
H. Asakura ◽  
S. S. C. Yen

Recently, we reported that the thecal compartment of the human ovary contains a CRF system replete with gene expression and protein for corticotropin-releasing factor (CRF), CRF-Receptor 1 (CRF-R1), and the blood-derived high affinity CRF-binding protein (CRF-BP). Granulosa cells are devoid of the CRF system. The parallel increases in intensity of CRF, CRF-R1, and 17α-hydroxylase messenger ribonucleic acid (mRNA) and proteins in thecal cells with follicular maturation suggest that the intraovarian CRF system may play an autocrine role regulating androgen biosynthesis, with a downstream effect on estrogen production by granulosa cells. The functionality of the ovarian CRF system may be conditioned by the relative presence of plasma-derived CRF-BP by virtue of its localization of protein, but not transcript in thecal cells and its ability to compete with CRF for the CRF receptor. To further these findings, in the present study we have examined the effect of CRF on LH-stimulated 17α-hydroxylase (P450c17) gene expression and androgen production by isolated thecal cells from human ovarian follicles (11–13 mm). During the 48-h culture, addition of LH (10 ng/mL) to the medium increased by 5- and 6-fold dehydroepiandrosterone and androstenedione production by thecal cells. Remarkably, the LH-stimulated, but not basal, androgen production was inhibited by CRF in a time- and dose-dependent manner. The half-maximal (ID50) effect dose of CRF occurred at 5 × 10−8 mol/L, and at a maximal concentration of 10−6 mol/L, CRF completely inhibited LH-stimulated androgen production. This inhibitory effect of CRF became evident at 12 h (45%), and by 24 h the effect was more pronounced, with a 70% reduction from baseline. As determined by Northern analyses, CRF dose dependently decreased LH-stimulated P450c17 mRNA levels, with a maximal inhibition of 85% P450c17 gene expression at a CRF concentration of 10−6 mol/L. With the addition of 10−6 mol/L of the antagonist α-helical CRF-(9–41), the inhibitory effect of CRF was partially reversed for both P450c17 mRNA (75%) and androgen production (50%), indicating the CRF-R1-mediated event. In conclusion, the present study demonstrated a potent inhibitory effect of CRF on LH-stimulated dehydroepiandrosterone and androstenedione production that appears to be mediated through the reduction of P450c17 gene expression. Thus, the ovarian CRF system may function as autocrine regulators for androgen biosynthesis in the thecal cell compartment to maintain optimal substrate for estrogen biosynthesis by granulosa cells. Further studies to define the role of CRF-BP in the endocrine modulation of the intraovarian CRF system are needed.


Endocrinology ◽  
2012 ◽  
Vol 153 (6) ◽  
pp. 2851-2860 ◽  
Author(s):  
Bayasula ◽  
Akira Iwase ◽  
Tohru Kiyono ◽  
Sachiko Takikawa ◽  
Maki Goto ◽  
...  

The ovary is a complex endocrine organ responsible for steroidogenesis and folliculogenesis. Follicles consist of oocytes and two primary steroidogenic cell types, the granulosa cells, and the theca cells. Immortalized human granulosa cells are essential for researching the mechanism of steroidogenesis and folliculogenesis. We obtained granulosa cells from a 35-yr-old female and immortalized them by lentivirus-mediated transfer of several genes so as to establish a human nonluteinized granulosa cell line (HGrC1). We subsequently characterized HGrC1 and investigated its steroidogenic performance. HGrC1 expressed enzymes related to steroidogenesis, such as steroidogenic acute regulatory protein, CYP11A, aromatase, and gonadotropin receptors. Stimulation with FSH increased the mRNA levels of aromatase, which consequently induced the aromatization of androstenedione to estradiol. Activin A increased the mRNA levels of the FSH receptor, which were synergistically up-regulated with FSH stimulation. HGrC1 also expressed a series of ligands and receptors belonging to the TGF-β superfamily. A Western blot analysis showed that bone morphogenetic protein (BMP)-4, BMP-6, and BMP-7 phosphorylated small mother against decapentaplegic (Smad)1/5/8, whereas growth differentiation factor-9 phosphorylated Smad2/3. BMP-15 and anti-Müllerian hormone phosphorylated Smad1/5/8 while also weakly phosphorylating Smad2/3. These results indicate that HGrC1 may possess the characteristics of granulosa cells belonging to follicles in the early stage. HGrC1 might also be capable of displaying the growth transition from a gonadotropin-independent status to gonadotropin-dependent one.


1992 ◽  
Vol 9 (3) ◽  
pp. 309-312 ◽  
Author(s):  
P.F. Whitelaw ◽  
C.D. Smyth ◽  
C.M. Howles ◽  
S.G. Hillier

ABSTRACT Current understanding of the endocrine and paracrine regulation of follicular oestrogen synthesis predicts that aromatase cytochrome P450 (P450arom) mRNA is inducible by FSH in granulosa cells. LH receptor mRNA is constitutively expressed in thecal/interstital cells, and is also thought to be induced in granulosa cells in response to joint stimulation by FSH and oestrogen. This study provides direct evidence that FSH induces the ovarian P450arom gene selectively, perhaps exclusively, in the granulosa cells of Graafian follicles. FSH-induction of LH receptor mRNA occurs simultaneously but is independent of oestrogen synthesis per se.


2020 ◽  
Vol 103 (3) ◽  
pp. 583-598
Author(s):  
Patricia G Tremblay ◽  
Marc-André Sirard

Abstract The female reproductive function largely depends on timing and coordination between follicle-stimulating hormone (FSH) and luteinizing hormone. Even though it was suggested that these hormones act on granulosa cells via shared signaling pathways, mainly protein kinases A, B, and C (PKA, PKB, and PKC), there is still very little information available on how these signaling pathways are regulated by each hormone to provide such differences in gene expression throughout folliculogenesis. To obtain a global picture of the principal upstream factors involved in PKA, PKB, and PKC signaling in granulosa cells, human granulosa-like tumor cells (KGN) were treated with FSH or specific activators (forskolin, SC79, and phorbol 12-myristate 13-acetate) for each pathway to analyze gene expression with RNA-seq technology. Normalization and cutoffs (FC 1.5, P ≤ 0.05) revealed 3864 differentially expressed genes between treatments. Analysis of major upstream regulators showed that PKA is a master kinase of early cell differentiation as its activation resulted in the gene expression profile that accompanies granulosa cell differentiation. Our data also revealed that the activation of PKC in granulosa cells is also a strong differentiation signal that could control “advanced” differentiation in granulosa cells and the inflammatory cascade that occurs in the dominant follicle. According to our results, PKB activation provides support for PKA-stimulated gene expression and is also involved in granulosa cell survival throughout follicular development. Taken together, our results provide new information on PKA, PKB, and PKC signaling pathways and their roles in stimulating a follicle at the crossroad between maturation/ovulation and atresia.


1993 ◽  
Vol 5 (1) ◽  
pp. 95
Author(s):  
RT Denkova ◽  
IG Ivanov ◽  
LN Kanchev

The ability of porcine granulosa cells to release a progesterone inhibiting substance(s) was examined in vitro. Granulosa cells (SGCs, MGCs and LGCs) were harvested from small, medium or large antral follicles respectively. The effect of granulosa cell conditioned media obtained from small follicles (SGCCM) was studied in the culture of LGCs by estimation of progesterone secretion; the conditioned media evoked the inhibition of progesterone secretion by the LGCs. SGCCM produced by various numbers of cultured granulosa cells showed a dose-related inhibition of progesterone production. A maximum inhibitory effect was noted when a 5-fold concentration of SGCCM was used. The addition of SGCCM had no effect on the growth of the cultured cells. The factor(s) inhibiting progesterone secretion appeared to be a nonsteroidal substance of molecular mass greater than 10 kDa and was heat-stable and trypsin-sensitive. The data presented support the suggestion that the conditioned media generated by primary cultures of SGCs contain nonsteroidal regulators capable of inhibiting progesterone secretion by cultured LGCs; this inhibitory activity can play an important autocrine regulatory role in the process of follicular differentiation.


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