scholarly journals Growth Differentiation Factor-9 Inhibits 3′5′-Adenosine Monophosphate-Stimulated Steroidogenesis in Human Granulosa and Theca Cells

2002 ◽  
Vol 87 (6) ◽  
pp. 2849-2856 ◽  
Author(s):  
Noriko Yamamoto ◽  
Lane K. Christenson ◽  
Jan M. McAllister ◽  
Jerome F. Strauss

Growth differentiation factor-9 (GDF-9), a member of the transforming growth factor superfamily, modulates the development and function of granulosa and theca cells. Targeted deletion of GDF-9 in the mouse revealed that GDF-9 was essential for the establishment of the thecal cell layer during early folliculogenesis. During later stages of follicular development, the roles of GDF-9 are less well understood, but it has been postulated that oocyte-derived GDF-9 may prevent premature luteinization of follicular cells, based on its ability to modulate steroidogenesis by rodent ovarian cells. In the rodent, GDF-9 is expressed solely by the oocyte from the early primary follicular stage through ovulation. Recent studies in the rhesus monkey demonstrated that granulosa cells express GDF-9, suggesting a broader role for this protein in ovarian function in primates. We examined the effect of recombinant GDF-9 on proliferating human granulosa and thecal cell steroidogenesis and the expression of steroidogenic acute regulatory protein (StAR), P450 side-chain cleavage, and P450 aromatase. We also examined granulosa cell GDF-9 expression by quantitative RT-PCR and by Western analysis. GDF-9 inhibited 8-Br-cAMP-stimulated granulosa progesterone synthesis by approximately 40%, but did not affect basal progesterone production. Concordant with reduced steroid production, 8-Br-cAMP-stimulated StAR protein expression was reduced approximately 40% in granulosa cells, as were expression of StAR mRNA and StAR promoter activity. Additionally, GDF-9 inhibited 8-Br-cAMP-stimulated expression of P450 side-chain cleavage and P450 aromatase. Human granulosa cells expressed GDF-9, as determined by RT-PCR and Western analysis. Treatment of human thecal cells with GDF-9 blocked forskolin-stimulated progesterone, 17α-hydroxyprogesterone, and dehydroepiandrosterone synthesis. Thecal cells exhibited greater sensitivity to GDF-9, suggesting that this cell may be a primary target of GDF-9. Moreover, GDF-9 increased thecal cell numbers during culture, but had no effect on granulosa cell growth. Our findings implicate GDF-9 in the modulation of follicular steroidogenesis, especially theca cell function. Because GDF-9 mRNA and protein are detectable in granulosa-lutein cells after the LH surge, the concept of GDF-9 as a solely oocyte-derived luteinization inhibitor needs to be reevaluated.

1996 ◽  
Vol 151 (3) ◽  
pp. 365-373 ◽  
Author(s):  
L J Spicer ◽  
T D Hamilton ◽  
B E Keefer

Abstract Studies were conducted to determine the importance of de novo cholesterol synthesis and cholesterol side-chain cleavage enzyme in the action of IGF-I in bovine granulosa and thecal cells. Granulosa and thecal cells from bovine follicles were cultured for 2 days in 10% fetal calf serum and then treated with luteinizing hormone (100 ng/ml) and IGF-I (0 or 100 ng/ml) for an additional 2 days in serum-free medium. During the last 24 h of treatment, cells were concomitantly treated with simvastatin (0, 0·5 or 5 μg/ml) or 25-hydroxycholesterol (0 or 10 μg/ml). Simvastatin, a potent inhibitor of the key enzyme controlling de novo cholesterol synthesis, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, completely inhibited (P<0·05) progesterone production by granulosa cells and progesterone and androstenedione production by thecal cells. Simvastatin also inhibited (P<0·05) granulosa cell and thecal cell proliferation. Concomitant treatment with mevalonate, an immediate product of HMG-CoA reductase, attenuated the inhibitory effect of simvastatin on progesterone and androstenedione production by thecal cells and blocked the inhibitory effect of simvastatin on cell proliferation. The addition of 25-hydroxycholesterol, a substrate for cholesterol side-chain cleavage enzyme, had no effect (P>0·10) on IGF-I-stimulated progesterone or androstenedione production by thecal cells and actually inhibited (P<0·05) IGF-I-stimulated progesterone production by granulosa cells. These results provide indirect evidence indicating that stimulation of HMG-CoA reductase is an important locus of IGF-I action in bovine granulosa and thecal cells, whereas IGF-I has little or no effect on side-chain cleavage enzyme activity in these same cell types under the culture conditions employed. Journal of Endocrinology (1996) 151, 365–373


2002 ◽  
Vol 174 (3) ◽  
pp. 499-507 ◽  
Author(s):  
JM Silva ◽  
CA Price

The earliest biochemical indicators of ovarian follicle deviation in cattle include lower oestradiol and free IGF concentrations in subordinate compared with dominant follicles. We determined if decreases in FSH, IGF-I or insulin cause decreased P450 aromatase (P450arom) or P450 cholesterol side-chain cleavage (P450scc) mRNA expression in oestrogenic bovine granulosa cells in vitro. In the first experiment, cells obtained from small follicles (2-5 mm diameter) were cultured in serum-free medium supplemented with physiological concentrations of FSH, IGF-I and insulin for 4 days. A decrease in specific hormone concentration was produced by replacing 70% of spent medium with medium devoid of FSH, insulin, or insulin and IGF-I on day 4 and again on day 5 of culture. Cultures were terminated on day 7. A reduction in FSH concentrations during the last 3 days of culture decreased P450arom and P450scc mRNA levels. A reduction in insulin reduced P450arom but not P450scc mRNA levels, and a reduction of both insulin and IGF-I concentrations further decreased P450arom mRNA levels and decreased P450scc mRNA levels. In a second experiment, cells obtained from small follicles (2-5 mm diameter) were cultured with insulin (100 ng/ml) without FSH for 4 days, and then insulin was withdrawn from the culture and FSH added for a further 3 days. The withdrawal of insulin decreased (P<0.02) oestradiol accumulation and reduced P450arom mRNA to below detectable levels, but did not affect P450scc mRNA levels. The addition of FSH transiently increased oestradiol secretion and P450arom mRNA levels, but P450arom mRNA levels were undetectable at the end of the culture period. The addition of FSH significantly enhanced P450scc mRNA levels and progesterone accumulation. These data demonstrated that a reduction of insulin-like activity reduced aromatase gene expression in bovine follicles without necessarily affecting progesterone synthetic capability, and thus may initiate follicle regression in cattle at the time of follicle divergence.


Reproduction ◽  
2009 ◽  
Vol 138 (6) ◽  
pp. 961-969 ◽  
Author(s):  
P L Rangel ◽  
A Rodríguez ◽  
S Rojas ◽  
P J Sharp ◽  
C G Gutierrez

The chicken ovary is organized into a hierarchy of yellow yolky follicles that ovulate on successive days. Active or passive immunization of laying hens against testosterone blocks ovulation without affecting follicle development. Testosterone may play a role in pre-ovulatory follicle maturation by stimulating granulosa progesterone production. We assessed whether this stimulus is dose-related and depends on the maturity of the donor follicle, and if it does so by stimulating granulosa cell STAR, P450 cholesterol side-chain cleavage (P450scc), and LH receptor (LHCGR) mRNAs expression. Progesterone production by granulosa cells from F1, F3, and F4 follicles, cultured for 3 h without testosterone was greater in cells collected 11–14 h than 1–4 h after ovulation. These differences in progesterone production were less pronounced after granulosa cells had been cultured for 24 h. Culture of granulosa cells for 3 or 24 h with testosterone (1–100 ng/ml) stimulated progesterone production in cells collected from F4, F3, or F1 follicles 1–4, or 11–14 h after ovulation. Testosterone (0–4000 ng/ml) alone or in combination with LH (0–100 ng/ml) increased progesterone production by F1 granulosa cells, collected 1–4 and 11–14 h after ovulation and cultured for 3 h. Finally, testosterone (10 or 100 ng/ml) increased STAR, P450scc, and LHCGR mRNAs, when added to 3 h cultures of F1 granulosa cells. In conclusion, testosterone stimulates granulosa cell progesterone production in hen pre-ovulatory hierarchical follicles irrespective of maturational state, acting alone or additively with LH. We propose that testosterone promotes granulosa cell maturation to facilitate the pre-ovulatory release of LH.


Endocrinology ◽  
2007 ◽  
Vol 148 (2) ◽  
pp. 726-734 ◽  
Author(s):  
Deeksha Saxena ◽  
Rosalba Escamilla-Hernandez ◽  
Lynda Little-Ihrig ◽  
Anthony J. Zeleznik

Granulosa cells express the closely related orphan nuclear receptors steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1). To determine whether SF-1 and LRH-1 have differential effects on steroid production, we compared the effects of overexpressing LRH-1 and SF-1 on estrogen and progesterone production by undifferentiated rat granulosa cells. Adenovirus mediated overexpression of LRH-1 or SF-1 had qualitatively similar effects. Neither LRH-1 nor SF-1 alone stimulated estrogen or progesterone production, but when combined with FSH and testosterone, each significantly augmented progesterone production and mRNAs for cholesterol side-chain cleavage enzyme and 3β-hydroxysteroid dehydrogenase above that observed with FSH alone, with SF-1 being more effective than LRH-1. LRH-1 did not augment FSH-stimulated estrogen production, whereas SF-1 produced only a slight (∼30%) augmentation of FSH-stimulated estrogen production. The stimulatory actions of both were reduced by overexpression of dosage-sensitive sex reversal, adrenal hypoplasia congenita, critical region on the X chromosome, gene 1. Expression of either LRH-1 or SF-1 together with constitutively active protein kinase B in the absence of FSH stimulated progesterone production and mRNAs for 3β-hydroxysteroid dehydrogenase and cholesterol side-chain cleavage enzyme but did not stimulate estrogen production or mRNA for aromatase. These findings demonstrate that LRH-1 and SF-1 have qualitatively similar actions on FSH-stimulated estrogen and progesterone production, which would suggest that these factors may have overlapping actions in the regulation of steroidogenesis that accompanies granulosa cell differentiation.


1994 ◽  
Vol 12 (2) ◽  
pp. 239-249 ◽  
Author(s):  
E L Yong ◽  
S G Hillier ◽  
M Turner ◽  
D T Baird ◽  
S C Ng ◽  
...  

ABSTRACT The co-ordinated biosynthesis of progesterone and oestradiol in the human ovary is critical for reproductive cyclicity and eventual pregnancy. The crucial regulatory enzymes for progesterone and oestradiol biosynthesis in granulosa cells are the cholesterol side-chain cleavage (P450scc) and aromatase (P450arom) enzymes respectively. We utilized the cDNA sequences encoding P450arom and P450scc to examine the roles of FSH and LH, and their intracellular second messenger, cyclic AMP (cAMP), in regulating steroidogenic gene expression. Mature granulosa cells (aspirated before the onset of the endogenous LH surge) and granulosa lutein cells (obtained after an ovulatory dose of human chorionic gonadotrophin) were cultured for 4 days with FSH, LH or dibutyryl cAMP (dbcAMP). After the period of culture, total RNA was extracted from granulosa cells and Northern analyses were performed utilizing 32P-labelled cDNAs encoding P450arom and P450scc. Spent culture media were analysed for steroid and cAMP content. Both FSH and LH strongly stimulated P450arom mRNA expression and oestradiol production in mature granulosa cells. On the other hand, P450scc mRNA expression and progesterone biosynthesis were weakly induced by FSH; maximal synthesis occurred only in the presence of LH. With both gonadotrophins at equivalent concentrations, LH generated a 30-fold higher level of cAMP than FSH. Furthermore, the differential effects of FSH and LH on P450 mRNA expression were reproduced by the presence of low and high concentrations of dbcAMP respectively. LH (and high levels of dbcAMP) increased P450arom mRNA expression in mature granulosa cells but inhibited its accumulation in granulosa lutein cells. In contrast, it stimulated P450scc mRNA expression and progesterone synthesis in both mature granulosa and granulosa lutein cells. Therefore, FSH/low cAMP levels stimulated P450arom gene expression and oestradiol production, while LH/high cAMP levels maximally induced P450scc gene expression and function, in a development-related manner consistent with steroid production in vivo. These findings support the hypothesis that one set of genes (like P450arom) in human granulosa cells is regulated by FSH/low cAMP levels and another (like P450scc) by LH/high cAMP levels.


2003 ◽  
Vol 176 (1) ◽  
pp. 151-161 ◽  
Author(s):  
V Sriraman ◽  
MR Sairam ◽  
AJ Rao

The relative role of LH and FSH in regulation of differentiation of Leydig cells was assessed using an ethane 1,2-dimethylsulfonate (EDS)-treated rat model in which endogenous LH or FSH was neutralized from day 3 to day 22 following EDS treatment. Serum testosterone and the in vitro response of the purified Leydig cells to human chorionic gonadotropin (hCG) was monitored. In addition RNA was isolated from the Leydig cells to monitor the steady-state mRNA levels by RT-PCR for 17alpha-hydroxylase, side chain cleavage enzyme, steroidogenic acute regulatory protein (StAR), LH receptor, estrogen receptor (ER-alpha) and cyclophilin (internal control). Serum testosterone was undetected and the isolated Leydig cells secreted negligible amount of testosterone on stimulation with hCG in the group of rats that were treated with LH antiserum following EDS treatment. RT-PCR analysis revealed the absence of message for cholesterol side chain cleavage enzyme and 17alpha-hydroxylase although ER-alpha and LH receptor mRNA could be detected, indicating the presence of undifferentiated precursor Leydig cells. In contrast, the effects following deprival of endogenous FSH were not as drastic as seen following LH neutralization. Deprival of endogenous FSH in EDS-treated rats led to a significant decrease in serum testosterone and in vitro response to hCG by the Leydig cells. Also, there was a significant decrease in the steady-state mRNA levels of 17alpha-hydroxylase, cholesterol side chain cleavage enzyme, LH receptor and StAR as assessed by a semiquantitative RT-PCR. These results establish that while LH is obligatory for the functional differentiation of Leydig cells, repopulation of precursor Leydig cells is independent of LH, and also unequivocally establish an important role for FSH in regulation of Leydig cell function.


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