scholarly journals Bone morphogenetic protein-6 enhances gonadotrophin-dependent progesterone and inhibin secretion and expression of mRNA transcripts encoding gonadotrophin receptors and inhibin/activin subunits in chicken granulosa cells

Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Sara L Al-Musawi ◽  
Richard T Gladwell ◽  
Philip G Knight
Keyword(s):  
Bone Morphogenetic Protein ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Dependent Manner ◽  
Cell Type ◽  
Inhibin A ◽  
Theca Cells ◽  
Subunit Mrna ◽  
Morphogenetic Protein

The aims were to examine ovarian expression of bone morphogenetic protein (BMP) ligands/receptor mRNAs in the chicken and to test the hypothesis that theca-derived BMP(s) modulates granulosa cell function in a paracrine manner. RT-PCR revealed expression of multiple BMPs in granulosa and theca cells from prehierarchical and preovulatory follicles with greater expression in theca cells; both cell types expressed BMP receptors-IA, -IB and -II consistent with tissue responsiveness. Preovulatory granulosa cells (F1, F2 and F3/4) were cultured with BMP-6 (expressed by theca but not granulosa) in the presence/absence of LH, FSH or 8-Br-cAMP. BMP-6 increased ‘basal’ and gonadotrophin-induced inhibin-A and progesterone secretion by each cell type but did not enhance the effect of 8-Br-cAMP. This indicates that the observed synergism between BMP-6 and gonadotrophin might involve BMP-induced up-regulation of gonadotrophin receptors. In support of this, BMP-6 alone increased LH-receptor (LHR) mRNA in F1 cells and FSH-receptor (FSHR) mRNA in F1, F2 and F3/4 cells. BMP-6 also enhanced LH/FSH-induced LHR transcript amount in each cell type but did not raise FSHR transcript amounts above those induced by BMP-6 alone. To further explore BMP-6 action on inhibin-A secretion, we quantified inhibin/activin subunits (α, βA, βB) mRNAs. Consistent with its effect on inhibin-A secretion, BMP-6 enhanced ‘basal’ expression of α- and βA-subunit mRNA in F1, F2 and F3/4 cells, and βB-subunit mRNA in F3/4 cells. BMP-6 markedly enhanced FSH/LH-induced expression of α-subunit in all follicles and FSH-induced βA-subunit in F2 and F3/4 follicles but not in F1 follicles. Neither BMP-6 alone, nor FSH/LH alone, affected ‘basal’ βB mRNA abundance. However, co-treatment with gonadotrophin and BMP-6 greatly increased βB-subunit expression, the response being lowest in F1 follicles and greatest in F3/4 follicles. Collectively, these results support the hypothesis that intraovarian BMPs of thecal origin have a paracrine role in modulating granulosa cell function in the chicken in a preovulatory stage-dependent manner.

scholarly journals Activation of the Bone Morphogenetic Protein Signaling Pathway Induces Inhibin βB-Subunit mRNA and Secreted Inhibin B Levels in Cultured Human Granulosa-Luteal Cells

2002 ◽  
Vol 87 (3) ◽  
pp. 1254-1261 ◽  
Author(s):  
Risto Jaatinen ◽  
Jonas Bondestam ◽  
Taneli Raivio ◽  
Kristiina Hildén ◽  
Leo Dunkel ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Signaling Pathway ◽  
Granulosa Cell ◽  
Bmp Signaling ◽  
Inhibin B ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Subunit Mrna ◽  
Morphogenetic Protein

During the human menstrual cycle the circulating levels of inhibin B, a dimer of inhibin α- and βB-subunits, fluctuate in a fashion distinct from that of inhibin A, the α-βA-subunit dimer. This suggests that human inhibin subunits are each regulated in a distinct manner in human ovarian granulosa cells by endocrine and local factors. We have previously shown using cultures of human granulosa-luteal (hGL) cells that gonadotropins stimulate the steady state mRNA levels of inhibin α- and βA-subunits, but not those of the βB-subunit, which, on the other hand, are up-regulated by, for instance, activin and TGFβ. We recently identified the TGFβ gene family member bone morphogenetic protein-3 (BMP-3) as a granulosa cell-derived growth factor, but whether BMP-3 or other structurally related BMPs regulate human granulosa cell inhibin production is not known. We show here that hGL cells express mRNAs for distinct serine/threonine kinase receptors (BMP-RIA and BMP-RII) and Smad signaling proteins (Smad1, Smad4, and Smad5) involved in the mediation of cellular effects of BMPs. Subsequently, we determined in hGL cell cultures the effects of distinct members of the BMP family previously found to be expressed in mammalian ovaries. Recombinant BMP-2 induces potently in a time- and concentration-dependent manner the expression of the inhibin βB-subunit mRNAs in hGL cells without affecting the levels of α- or βA-subunit mRNAs. BMP-6 has a similar, but weaker, effect than BMP-2, whereas BMP-3 and its close homolog, BMP-3b (also known as growth differentiation factor-10) had no effect on inhibin subunit mRNA expression. hCG treatment of hGL cells was previously shown to abolish the stimulatory effect of activin on βB-subunit mRNA levels, and here hCG is also shown to suppress the effect of BMP-2. Furthermore, BMP-2 stimulates hGL cell secreted dimeric inhibin B levels in a concentration-dependent manner. Depending on the experiment, maximal increases in inhibin B levels of 6- to 28-fold above basal levels were detected during a 72-h culture period. We conclude that activation of the BMP-signaling pathway in hGL cells stimulates inhibin βB-subunit mRNA levels and leads at the protein level to a dramatic stimulation of secreted inhibin B dimers. Our results are consistent with the suggestion that in addition to the distinct activin- and TGFβ-activated signaling pathways, the BMP-activated pathway is likely to be implicated in the complex regulation of inhibins in the human ovary.

scholarly journals The role of IGFs in the regulation of ovarian follicular growth in the brushtail possum (Trichosurus vulpecula)

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Jennifer L Juengel ◽  
Lisa J Haydon ◽  
Brigitta Mester ◽  
Brian P Thomson ◽  
Michael Beaumont ◽  
...  
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Antral Follicle ◽  
Brushtail Possum ◽  
Follicular Growth ◽  
Theca Cells ◽  
Ovarian Follicular Growth

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro. Both granulosa and theca cells synthesize IGF mRNAs, with the theca expressing IGF1 mRNA and granulosa cell expressing IGF2 mRNA. Oocytes and granulosa cells express IGF1R. Granulosa and theca cells expressed IGFBP mRNAs, although the pattern of expression differed between the BPs. IGFBP5 mRNA was differentially expressed as the follicles developed with granulosa cells of antral follicles no longer expressing IGFBP5 mRNA, suggesting an increased IGF bioavailability in the antral follicle. The IGFBP protease, PAPPA mRNA, was also expressed in granulosa cells of growing follicles. Both IGF1 and IGF2 stimulated thymidine incorporation but had no effect on progesterone production. Thus, IGF may be an important regulator of ovarian follicular development in marsupials as has been shown in eutherian mammals.

scholarly journals Non-canonical progesterone signaling in granulosa cell function

Reproduction ◽  
2014 ◽  
Vol 147 (5) ◽  
pp. R169-R178 ◽  
Author(s):  
John J Peluso ◽  
James K Pru
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Polycystic Ovarian Syndrome ◽  
Cell Function ◽  
Reproductive Capacity ◽  
Dependent Manner ◽  
Follicle Growth ◽  
Altered Expression ◽  
Ovarian Syndrome ◽  
Enhancer Factor

It has been known for over 3 decades that progesterone (P4) suppresses follicle growth. It has been assumed that P4 acts directly on granulosa cells of developing follicles to slow their development, as P4 inhibits both mitosis and apoptosis of cultured granulosa cells. However, granulosa cells of developing follicles of mice, rats, monkeys, and humans do not express the A or B isoform of the classic nuclear receptor for P4 (PGR). By contrast, these granulosa cells express other P4 binding proteins, one of which is referred to as PGR membrane component 1 (PGRMC1). PGRMC1 specifically binds P4 with high affinity and mediates P4's anti-mitotic and anti-apoptotic action as evidenced by the lack of these P4-dependent effects in PGRMC1-depleted cells. In addition, mice in which PGRMC1 is conditionally depleted in granulosa cells show diminished follicle development. While the mechanism through which P4 activation of PGRMC1 affects granulosa cell function is not well defined, it appears that PGRMC1 controls granulosa cell function in part by regulating gene expression in T-cell-specific transcription factor/lymphoid enhancer factor-dependent manner. Clinically, altered PGRMC1 expression has been correlated with premature ovarian failure/insufficiency, polycystic ovarian syndrome, and infertility. These collective studies provide strong evidence that PGRMC1 functions as a receptor for P4 in granulosa cells and that altered expression results in compromised reproductive capacity. Ongoing studies seek to define the components of the signal transduction cascade through which P4 activation of PGRMC1 results in the regulation of granulosa cell function.

Modulation of differentiation of rat granulosa cells in vitro by interferon-γ

1992 ◽  
Vol 133 (1) ◽  
pp. 131-139 ◽  
Author(s):  
S. Xiao ◽  
J. K. Findlay
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Inhibitory Effect ◽  
Interferon Γ ◽  
Detectable Effect ◽  
Aromatase Activity ◽  
Dependent Manner ◽  
Ifn Γ

ABSTRACT The effects of recombinant rat interferon-γ (rRaIFN-γ) and rat IFN (RaIFN, a mixture of IFN-γ and -α) on basal and FSH-induced ovarian granulosa cell function were studied. Granulosa cells were harvested from diethylstilboestrol-treated immature rats and cultured (2 × 105 viable cells/well per 0·5 ml) in serumfree medium with or without treatment for 48 h. In the presence of FSH (20 ng/ml), rRaIFN-γ (10–1000 U/ml) significantly inhibited FSH-stimulated aromatase activity (76·4 ± 2·3% maximum inhibition compared with FSH treatment alone), inhibin (40·4 ± 3·7%), progesterone (47·7 ± 8·6%) and 20α-hydroxypregn-4-en-3-one (20α-OHP) (51·8±1·7%) production in a dose-dependent manner. Furthermore, rRaIFN-γ inhibited FSH- and forskolin (FSK; 30 μmol/l)-induced extracellular cAMP accumulation (46·0 ± 6·6% and 29·1 ± 7·3% respectively). The inhibitory effect of rRaIFN-γ on FSK-induced cAMP was accompanied by decreased FSK-induced aromatase activity, inhibin, progesterone and 20α-OHP production. rRaIFN-γ had no detectable effect on aromatase activity, progesterone production and 20α-OHP production in the absence of FSH, but significantly stimulated basal inhibin production by 1·5-fold. rRaIFN-γ alone also caused a small but significant increase in basal levels of cAMP. The timecourse studies showed that FSH-induced aromatase activity and inhibin production were consistently suppressed by rRaIFN-γ, FSH-induced progesterone and 20α-OHP were inhibited at 1 and 2 days and then stimulated on days 3, 4 and 5 relative to FSH alone. There was no difference in DNA content between treatment and non-treatment wells during 5 days of culture. RaIFN had similar effects to rRaIFN-γ. We conclude that IFN-γ can inhibit FSH-induced granulosa cell differentiation and that, in the absence of FSH, IFN-γ stimulated undifferentiated granulosa cells to produce more inhibin. The mechanism of its action is likely to involve changes in cAMP production. Journal of Endocrinology (1992) 133, 131–139

scholarly journals A Novel Antagonistic Effect of the Bone Morphogenetic Protein System on Prolactin Actions in Regulating Steroidogenesis by Granulosa Cells

Endocrinology ◽  
2010 ◽  
Vol 151 (11) ◽  
pp. 5506-5518 ◽  
Author(s):  
Eri Nakamura ◽  
Fumio Otsuka ◽  
Kenichi Inagaki ◽  
Tomoko Miyoshi ◽  
Ryutaro Yamanaka ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Regulatory Protein ◽  
Antagonistic Effect ◽  
Janus Kinase ◽  
Progesterone Production ◽  
Morphogenetic Protein ◽  
High Concentrations ◽  
Steroidogenic Acute Regulatory

To investigate the mechanism by which prolactin (PRL) regulates follicular steroidogenesis in the ovary, we examined the functional roles of PRL in steroidogenesis using rat oocyte/granulosa cell coculture and focusing on the bone morphogenetic protein (BMP) system. The expression of long and short forms of PRL receptor (PRLR) were detected in both oocytes and granulosa cells, and PRL effectively up-regulated PRLR expression in granulosa cells in the presence of FSH. PRL suppressed FSH-induced estradiol production and increased FSH-induced progesterone production in granulosa cells. The PRL effects on FSH-induced progesterone were blocked by coculture with oocytes, implying roles of oocyte-derived factors in suppression of progesterone production in PRL-exposed granulosa cells. In accordance with the data for steroids, FSH-induced aromatase expression was suppressed by PRL, whereas FSH-induced steroidogenic acute regulatory protein, P450scc (P450 side-chain cleavage enzyme), and 3β-hydroxysteroid dehydrogenase type 2 levels were amplified by PRL. However, forskolin- and N6,O2-dibutyryl cAMP-induced steroid levels and FSH- and forskolin-induced cAMP were not affected by PRL, suggesting that PRL action on FSH-induced steroidogenesis was not due to cAMP-protein kinase A regulation. Treatment with a BMP-binding protein, noggin, facilitated PRL-induced estradiol reduction, and noggin increased PRL-induced progesterone production in FSH-treated granulosa cells cocultured with oocytes, suggesting that endogenous BMPs reduce progesterone but increase estradiol when exposed to high concentrations of PRL. PRL increased the expression of BMP ligands in oocyte/granulosa cell coculture and augmented BMP-induced phosphorylated mothers against decapentaplegic 1/5/8 signaling by reducing inhibitory phosphorylated mothers against decapentaplegic 6 expression through the Janus kinase/signal transducer and activator of transcription (STAT) pathway. In addition to STAT activation, PRL enhanced FSH-induced MAPK phosphorylation in granulosa cells, in which ERK activation was preferentially involved in suppression of FSH-induced estradiol. Furthermore, noggin treatment enhanced PRLR signaling including MAPK and STAT. Considering that BMPs suppressed PRLR in granulosa cells, it is likely that the BMP system in growing follicles plays a key role in antagonizing PRLR signaling actions in the ovary exposed to high concentrations of PRL.

Effects of recombinant bovine somatotrophin, insulin-like growth factor-I and insulin on bovine granulosa cell steroidogenesis in vitro

1994 ◽  
Vol 143 (1) ◽  
pp. 157-164 ◽  
Author(s):  
J G Gong ◽  
D McBride ◽  
T A Bramley ◽  
R Webb
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Dependent Manner ◽  
Serum Free ◽  
Factor I ◽  
Igf I ◽  
Serum Free Conditions ◽  
Dose Dependent ◽  
Bovine Somatotrophin ◽  
Cells Cultured

Abstract Our previous studies have demonstrated that physiological concentrations of metabolic hormones, including recombinant bovine somatotrophin (BST), insulin-like growth factor-I (IGF-I) and insulin, can significantly stimulate the proliferation of bovine granulosa cells cultured under serum-free conditions. In this study we investigated the effects of these factors on bovine granulosa cell steroidogenesis using the same culture system. Bovine granulosa cells were obtained from antral follicles classified into three size classes: small, <5 mm; medium-sized, 5–10 mm and large, >10 mm in diameter. Whilst not affecting steroidogenesis by granulosa cells from small and medium-sized follicles, BST (10–1000 ng/ml) stimulated the secretion of both oestradiol and progesterone by granulosa cells from large follicles in a dose-dependent manner. Insulin (1–1000 ng/ml) and IGF-I (10–1000 ng/ml) stimulated the secretion of oestradiol and progesterone by granulosa cells from all three size categories of follicles in a dose-dependent manner. FSH (200 ng/ml) alone increased progesterone secretion by granulosa cells from all three size classes of follicles, but had no effect on oestradiol secretion by granulosa cells. Both IGF-I (200 ng/ml) and insulin (30 ng/ml) acted in synergy with FSH (200 ng/ml) to stimulate steroidogenesis by granulosa cells from all three size categories of follicles, but no such interaction was observed between BST (50 ng/ml) and FSH (200 ng/ml). In conclusion, BST, IGF-I and insulin significantly influence the steroidogenic activity of bovine granulosa cells cultured under serum-free conditions. However, unlike their effects on cell proliferation, the minimal effective concentrations of these factors required to stimulate granulosa cell steroidogenesis were higher than those observed in our previous studies in vivo. Journal of Endocrinology (1994) 143, 157–164

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