206. Differential regulation of activin and inhibin production by interleukin 1 (IL1), transforming growth factor β1 (TGFβ1) and protein kinase C (PKC) in the Sertoli cell and granulosa cell

2008 ◽  
Vol 20 (9) ◽  
pp. 6 ◽  
Author(s):  
V. Eede ◽  
J. A. Muir ◽  
A. E. O. 'Connor ◽  
W. R. Winnall ◽  
A. E. Drummond ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Sertoli Cell ◽  
Granulosa Cells ◽  
Sertoli Cells ◽  
Activin A ◽  
Inhibin B ◽  
Inhibin A ◽  
Α Subunit ◽  
Subunit Mrna ◽  
Subunit Expression

Activin and inhibin are gonadal regulatory proteins comprising an α-subunit and either a βA-subunit or βB-subunit (inhibin A or B), or two βA-subunits (activin A). Synthesis of the α-subunit, and the inhibins, is regulated by FSH via cAMP/protein kinase A. Regulation of the β-subunits in the gonads is less well defined, but the IL1/MAP kinase, TGFβ /Smad and PKC pathways have been implicated. Sertoli cells and granulosa cells were isolated from 18–22 day-old Sprague-Dawley rats under standard conditions and cultured with IL1, TGFβ1 and the PKC agonists, gonadotrophin releasing hormone (GnRH) or phorbol myristate acetate (PMA). Activin A, inhibin A and inhibin B were measured in culture medium (at 48h) by ELISA. Subunit mRNA expression was measured in cell extracts (at 4 h and 8h) using quantitative RT–PCR. IL1 stimulated βA-subunit and activin A production and inhibited α-subunit and βB-subunit expression and inhibin B production in Sertoli cells, but had no effect in granulosa cells. TGFβ1 stimulated activin A in both cell types, as well as the inhibins in granulosa cells. Surprisingly, TGFβ1 had no effect on Sertoli cell α-subunit or βA-subunit mRNA expression, but did cause a slight reduction of βB-subunit expression. GnRH increased activin A and inhibin A, but not inhibin B, production by granulosa cells and had no effect on Sertoli cells, which lack the GnRH receptor. However, direct activation of PKC by PMA stimulated βA-subunit mRNA expression and activin A production and decreased βB-subunit and inhibin B production by Sertoli cells, with marginal effects on inhibin A. These results indicate that activation of the TGFβ or PKC signalling pathways preferentially stimulates βA-subunit expression and/or translation, leading to increased activin A secretion by Sertoli cells and both activin A and inhibin A secretion by granulosa cells. The ability of IL1 to stimulate activin A is confined to the Sertoli cell.

scholarly journals Reciprocal regulation of activin A and inhibin B by interleukin-1 (IL-1) and follicle-stimulating hormone (FSH) in rat Sertoli cells in vitro

2005 ◽  
Vol 185 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Y Okuma ◽  
K Saito ◽  
A E O’Connor ◽  
D J Phillips ◽  
D M de Kretser ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Sertoli Cells ◽  
Interleukin 1 ◽  
Activin A ◽  
Inhibin B ◽  
Dibutyryl Camp ◽  
Inhibin A ◽  
Reciprocal Regulation ◽  
Α Subunit ◽  
Subunit Mrna

In several biological systems, the inhibin βA homodimer activin A is stimulated by, and in turn, inhibits the action of interleukin (IL)-1 (both IL-1α and IL-1β) and IL-6. The possibility that a similar regulatory relationship operates within the testis was investigated. Sertoli cells from immature (20-day-old) rats were cultured with human IL-1α or IL-1β, human IL-6 and/or ovine FSH or dibutyryl cAMP. Activin A and the inhibin dimers, inhibin A and inhibin B, were measured by specific ELISA. Immunoreactive inhibin (ir-inhibin) was measured by RIA. Activin/inhibin subunit mRNA expression was measured by quantitative real-time PCR. Both IL-1 isoforms, but not IL-6, stimulated activin A secretion through increased synthesis of βA-subunit mRNA. IL-1 also stimulated activin A secretion by testicular peritubular cells. In contrast to the effect on activin A, IL-1 suppressed inhibin βB-subunit and, to a lesser extent, α-subunit mRNA expression, thereby reducing basal and FSH-stimulated inhibin B secretion by the Sertoli cells. Conversely, FSH inhibited basal activin A secretion and antagonised the stimulatory effects of IL-1. Dibutyryl cAMP partially inhibited the action of IL-1 on activin A secretion, but had no significant effect on basal activin A secretion. Secretion of inhibin A was low in all treatment groups. These data demonstrate that IL-1 and FSH/cAMP exert a reciprocal regulation of activin A and inhibin B synthesis and release by the Sertoli cell, and suggest a role for activin A as a potential feedback regulator of IL-1 and IL-6 activity in the testis during normal spermatogenesis and in inflammation.

scholarly journals Pachytene spermatocytes in co-culture inhibit rat Sertoli cell synthesis of inhibin beta B-subunit and inhibin B but not the inhibin alpha-subunit

2002 ◽  
Vol 172 (3) ◽  
pp. 565-574 ◽  
Author(s):  
RJ Clifton ◽  
L O'Donnell ◽  
DM Robertson
Keyword(s):  
Mrna Expression ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Inhibin B ◽  
Alpha Subunit ◽  
Subunit Mrna ◽  
B Subunit ◽  
Subunit Expression ◽  
Pachytene Spermatocytes

This study investigates the effects of spermatogenic germ cells on inhibin alpha-subunit and beta B-subunit expression, and inhibin alpha-subunit and inhibin B production by rat Sertoli cells in vitro. Sertoli cells isolated from 19-day-old rats were cultured for 48 h at 32 degrees C, in the presence or absence of FSH (2.3-2350 mIU/ml), and in the presence of pachytene spermatocytes, round spermatids or cytoplasts of elongated spermatids purified from adult rat testis by elutriation and density gradient separation. Sertoli cell secretion of inhibin alpha-subunit and inhibin B, as measured by immunoassay, was dose-dependently stimulated by FSH (maximal stimulation 13- and 2-fold, respectively). Round spermatids or cytoplasts co-cultured with Sertoli cells had no effect on basal or FSH-induced secretion of inhibin alpha-subunit or inhibin B. When Sertoli cells were co-cultured with pachytene spermatocytes, inhibin alpha-subunit secretion was unaltered, while inhibin B secretion was suppressed in a cell concentration-dependent manner to reach a maximal suppression of 45% compared with Sertoli cells alone (P<0.01). A similar suppression in inhibin B was still observed (64% of Sertoli cells alone) when the pachytene spermatocytes were separated from Sertoli cells by a 0.45 microm pore membrane barrier in bicameral chambers. Pachytene spermatocytes also suppressed FSH-induced inhibin B levels in Sertoli cell co-cultures and this suppression was attributed to a decrease in basal inhibin B production rather than a change in FSH responsiveness. Quantitation of Sertoli cell inhibin alpha- and beta B-subunit mRNA by quantitative (real-time) PCR demonstrated that pachytene spermatocytes did not alter Sertoli cell alpha-subunit mRNA expression, but significantly (P<0.01) suppressed basal and FSH-induced beta B-subunit mRNA expression to a similar degree to that seen with inhibin B protein levels. It is concluded that pachytene spermatocytes in vitro suppress Sertoli cell inhibin B secretion via factor-mediated suppression of inhibin beta B-subunit expression. These findings support the hypothesis that specific germ cell types can influence inhibin B secretion by the testis independent of FSH regulation.

scholarly journals Temporal and hormonal regulation of inhibin protein and subunit mRNA expression by post-natal and immature rat ovaries

2000 ◽  
Vol 166 (2) ◽  
pp. 339-354 ◽  
Author(s):  
AE Drummond ◽  
M Dyson ◽  
E Thean ◽  
NP Groome ◽  
DM Robertson ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cell Cultures ◽  
Granulosa Cells ◽  
Inhibin B ◽  
Alpha Subunit ◽  
Inhibin A ◽  
Preantral Follicles ◽  
Subunit Mrna ◽  
Ovarian Cells ◽  
Old Rats

The contribution of specific follicle populations to dimeric inhibin production and inhibin subunit mRNA expression by the rat ovary has been investigated in two model systems, granulosa cells isolated from 25-day-old diethylstilboestrol (DES)-treated rats and post-natal rat ovaries, dispersed in culture or whole ovaries, using specific two-site immunoassays and 'real time' PCR. Media from FSH-stimulated granulosa cell cultures fractionated by gel filtration and RP-high performance liquid chromatography revealed two predominant peaks of alpha subunit activity which were attributed to alpha subunit and 31 k dimeric inhibin-A. The corresponding inhibin-B levels were low. FSH stimulation did not alter the ratio of inhibin-A:alpha subunit produced by granulosa cells. All three inhibin subunit mRNAs were expressed by granulosa cells, with eight-fold more alpha subunit mRNA relative to either of the beta subunits. Administration of DES to immature rats prior to the isolation of granulosa cells from the ovary led to beta(A) and beta(B) mRNA expression being down-regulated in the absence of any significant change in alpha subunit expression by the granulosa cells. Inhibin-A, -B and -alpha subunit were produced by basal and stimulated cultures of ovarian cells prepared from 4-, 8- and 12-day-old rats, indicating that primary, preantral and antral follicles contribute to total inhibin production. Consistent with these results, follicles within these ovaries expressed all three inhibin subunit mRNAs, with maximal expression observed in the ovaries of 8-day-old rats. The appearance of antral follicles in the ovary at day 12 led to a decline in the mRNA levels of each of the subunits but was most evident for the beta subunits. There was a profound influence of secondary preantral follicles on dimeric inhibin-A production, with FSH stimulation increasing inhibin-A relative to alpha subunit levels in cultures of ovarian cells prepared from 8-day-old rats. Thus, preantral follicles exposed to FSH contribute significantly to beta(A) subunit production by the ovary. In contrast, primary and preantral follicles did not produce inhibin-B in response to FSH stimulation. Transforming growth factor-beta (TGF-beta) enhanced, in a time-dependent manner, the production of the inhibin forms by ovarian cells in culture, although inhibin-B production was not responsive until day 8. The simultaneous treatment of ovarian cell cultures with FSH and TGF-beta elicited the greatest increases in production of all the inhibin forms. In summary, ovaries of 4-, 8- and 12-day-old rats expressed inhibin subunit mRNAs and produced dimeric inhibin-A and -B and free alpha subunit. Preantral follicles (day-8 ovarian cell cultures) were particularly sensitive to stimulation by FSH and TGF-beta and had a substantial capacity for inhibin production. The production of oestrogen by follicles may be instrumental in regulating inhibin production given that beta subunit mRNA expression was down-regulated by DES. The mechanisms by which inhibin-A and inhibin-B are individually regulated are likely to be similar during the post-natal period, when folliculogenesis is being established, and diverge thereafter, when inhibin-A becomes the predominant form in the fully differentiated ovary.

Effects of FSH and testosterone on highly purified rat Sertoli cells: inhibin α-subunit mRNA expression and inhibin secretion are enhanced by FSH but not by testosterone

1989 ◽  
Vol 122 (3) ◽  
pp. 757-762 ◽  
Author(s):  
A. M. W. Toebosch ◽  
D. M. Robertson ◽  
I. A. Klaij ◽  
F. H. de Jong ◽  
J. A. Grootegoed
Keyword(s):  
Mrna Expression ◽  
Effective Dose ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Osmotic Shock ◽  
Shock Treatment ◽  
Α Subunit ◽  
Subunit Mrna ◽  
Old Rats

ABSTRACT The effects of FSH and testosterone on inhibin mRNA expression and inhibin production by highly purified Sertoli cell preparations were examined. Sertoli cells were isolated from testes of 22-day-old rats by sequential trypsin, collagenase and hyaluronidase treatments, with subsequent osmotic shock treatment on day 3 of culture. Contamination by peritubular and germ cells was <0·5 and 1–3% respectively. Intracellular and secreted inhibin levels were measured by radioimmunoassay, using Sertoli cells which were incubated for 24 h in the absence or presence of FSH and testosterone from days 4 to 5 of culture. FSH stimulated the cellular inhibin content and the secreted inhibin level by four- and sevenfold respectively, with a half-maximal effective dose of 5–50 ng/ml. Under the present incubation conditions, testosterone (1 μmol/l) had no effect on immunoreactive inhibin levels in either the presence or absence of FSH. Similarly, the expression of inhibin α-subunit mRNA was increased following FSH stimulation, whereas testosterone had no effect. The expression of inhibin βB-subunit mRNAs was not influenced by FSH or testosterone. It is concluded that highly purified Sertoli cell preparations, with a very low number of peritubular or germ cells, are fully responsive to FSH with respect to inhibin mRNA expression and inhibin production. Journal of Endocrinology (1989) 122, 757–762

scholarly journals Growth Differentiation Factor-9 Stimulates Inhibin Production and Activates Smad2 in Cultured Rat Granulosa Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Jae-Sook Roh ◽  
Jonas Bondestam ◽  
Sabine Mazerbourg ◽  
Noora Kaivo-Oja ◽  
Nigel Groome ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Granulosa Cells ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Inhibin B ◽  
Inhibin A ◽  
Differentiation Factor ◽  
Growth Differentiation Factor 9 ◽  
Ovarian Inhibin ◽  
Stimulation Of

Abstract Ovarian inhibin production is stimulated by FSH and several TGFβ family ligands including activins and bone morphogenetic proteins. Growth differentiation factor-9 (GDF-9) derived by the oocyte is a member of the TGFβ/activin family, and we have previously shown that GDF-9 treatment stimulates ovarian inhibin-α content in explants of neonatal ovaries. However, little is known about GDF-9 regulation of inhibin production in granulosa cells and downstream signaling proteins activated by GDF-9. Here, we used cultured rat granulosa cells to examine the influence of GDF-9 on basal and FSH-stimulated inhibin production, expression of inhibin subunit transcripts, and the GDF-9 activation of Smad phosphorylation. Granulosa cells from small antral follicles of diethylstilbestrol-primed immature rats were cultured with FSH in the presence or absence of increasing concentrations of GDF-9. Secreted dimeric inhibin A and inhibin B were quantified using specific ELISAs, whereas inhibin subunit RNAs were analyzed by Northern blotting using 32P-labeled inhibin subunit cDNA probes. Similar to FSH, treatment with GDF-9 stimulated dose- and time-dependent increases of both inhibin A and inhibin B production. Furthermore, coincubation of cells with GDF-9 and FSH led to a synergistic stimulation of both inhibin A and inhibin B production. GDF-9 treatment also increased mRNA expression for inhibin-α and inhibin-β subunits. To investigate Smad activation, granulosa cell lysates were analyzed in immunoblots using antiphosphoSmad1 and antiphosphoSmad2 antibodies. GDF-9 treatment increased Smad2, but not Smad1, phosphorylation with increasing doses of GDF-9 leading to a dose-dependent increase in phosphoSmad2 levels. To further investigate inhibin-α gene promoter activation by GDF-9, granulosa cells were transiently transfected with an inhibin-α promoter-luciferase reporter construct and cultured with different hormones before assaying for luciferase activity. Treatment with FSH or GDF-9 resulted in increased inhibin-α gene promoter activity, and combined treatment with both led to synergistic increases. The present data demonstrate that oocyte-derived GDF-9, alone or together with pituitary-derived FSH, stimulates inhibin production, inhibin subunit mRNA expression, and inhibin-α promoter activity by rat granulosa cells. The synergistic stimulation of inhibin secretion by the paracrine hormone GDF-9 and the endocrine hormone FSH could play an important role in the feedback regulation of FSH release, thus leading to the modulation of follicle maturation and ovulation.

scholarly journals Changes in Circulating and Testicular Levels of Inhibin A and B and Activin A During Postnatal Development in the Rat

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3532-3541 ◽  
Author(s):  
Jeremy J. Buzzard ◽  
Kate L. Loveland ◽  
Moira K. O’Bryan ◽  
Anne E. O’Connor ◽  
Marilyn Bakker ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Postnatal Development ◽  
Sertoli Cell ◽  
Activin A ◽  
Inhibin B ◽  
Northern Analysis ◽  
Male Rat ◽  
Testicular Development ◽  
Inhibin A

Abstract This study describes the testicular levels of inhibin/activin subunits by Northern analysis and in situ hybridization and serum and testicular levels of inhibins A and B and activin A by enzyme linked immunosorbent assays (ELISA) during postnatal development in the rat. We show that serum inhibin A levels are less than 4 pg/ml throughout postnatal life. Serum inhibin B levels peak at 572 ± 119 pg/ml (mean ± se) at d 40 post partum (pp) before falling to 182 ± 35 pg/ml in mature males. Serum activin A decreases from 294 ± 29 pg/ml at d 6 to 132 ± 27 pg/ml at maturity. Within the testis, inhibin A levels fall from 0.330 ± 0.108 ng/g at d 15 to less than 0.004 ng/g at maturity. Inhibin B levels peak at 43.9 ± 4.2 ng/g at d 6 before falling to 1.6 ± 0.13 ng/g at maturity. Testicular activin A levels fall from 18.6 ± 2.2 ng/g at d 6 to 0.094 ± 0.013 ng/g at maturity. Northern profiles of testicular inhibin/activin subunits correlate with immunoreactive levels demonstrated by ELISA. In situ hybridization suggests that βA and βB subunit expression is largely restricted to the seminiferous tubule, particularly Sertoli cells, spermatogonia, and primary spermatocytes. These data support the view that inhibin B is the major inhibin in the male rat and that levels relate to Sertoli cell number and activity. Furthermore, the demonstration of high local concentrations of activin A during the period of Sertoli cell proliferation and the onset of spermatogenesis support its proposed role because a modulator of testicular development and function.

scholarly journals Follicular Cells Acquire Sertoli Cell Characteristics after Oocyte Loss

Endocrinology ◽  
2005 ◽  
Vol 146 (7) ◽  
pp. 2992-3004 ◽  
Author(s):  
Céline J. Guigon ◽  
Noëlline Coudouel ◽  
Séverine Mazaud-Guittot ◽  
Maguelone G. Forest ◽  
Solange Magre
Keyword(s):  
Sertoli Cell ◽  
Granulosa Cells ◽  
Sertoli Cells ◽  
Cell Junctions ◽  
Female Rats ◽  
Cell Phenotype ◽  
Molecular Characteristics ◽  
Specific Marker ◽  
Follicular Cells ◽  
Α Subunit

Abstract Although it has been suggested that in mammals the loss of female germ cells may induce the masculinization of the ovarian compartment, there has been as yet no conclusive demonstration. To directly address that question, the present study has been designed to determine the fate of follicular cells after oocyte loss. Using γ-irradiation to selectively deplete oocytes in nongrowing follicles in female rats, we show that follicular cells in oocyte-depleted follicles survive, proliferate, and subsequently acquire morphological characteristics of Sertoli cells: elongated cytoplasm, basal location of the nucleus, and specific Sertoli cell junctions, the ectoplasmic specializations. These Sertoli-like cells express, however, the female-specific marker FOXL2 (Forkhead L2) but not the male sex-specific marker SOX-9 (Sry-type high-mobility-group box transcription factor-9) underlying the maintenance of molecular characteristics of granulosa cells. Before transdifferentiating into Sertoli-like cells, follicular cells of oocyte-depleted follicles initiate the expression of anti-Mullerian hormone and inhibin α-subunit that are typically synthesized by granulosa cells from the onset of follicular growth. Experimental modifications of the endocrine balance of the irradiated females show that there is a close relationship between plasma FSH levels and the occurrence of Sertoli-like cells. In addition to providing experimental evidence for the crucial role of the oocyte in granulosa cell phenotype maintenance, these results emphasize that the transdifferentiation of granulosa cells into Sertoli cells occurs in a multistep fashion, requiring the maturation of granulosa cells and depending on the endocrine milieu.

In vitro regulation of rat Sertoli cell inhibin messenger RNA levels by transforming growth factor-β1 and tumour necrosis factor α

1995 ◽  
Vol 146 (3) ◽  
pp. 501-508 ◽  
Author(s):  
B Le Magueresse-Battistoni ◽  
A M Morera ◽  
M Benahmed
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Mrna Levels ◽  
Α Subunit ◽  
Subunit Mrna ◽  
Factor Α ◽  
Tgf Β1

Abstract In the present study, we examined the in vitro regulation of 20-day-old rat Sertoli cell inhibin α- and βB-subunits mRNA levels by transforming growth factor-β1 (TGF-β1) and tumour necrosis factor α (TNFα), two factors produced in the testis. Addition of TGF-β1 to highly purified cultured Sertoli cells resulted in a time- and dose-dependent enhancement in the α-subunit mRNA levels (ED50=2·4 pm; maximal increase of 2·6-fold after 48 h of treatment), without affecting the βB-subunit mRNA levels. Similarly, activin A up-regulated the α-but did not modulate the βB-subunit mRNA levels. By contrast, TNFα decreased in a time- and dose-dependent fashion the mRNA levels of the two inhibin subunits α and βB (IC50=29 pm for both subunits; maximal decrease of 4·4- and of 4-fold after 72 and 24 h of treatment for respectively the α- and βB-subunits). The effects of TGF-β1 and TNFα on inhibin mRNA levels occurred within a dose range that might be expected under physiological conditions. In addition, TGF-β1-treated Sertoli cells responded to FSH or dibutyryl cyclic AMP ((Bu)2cAMP) by a further and significant additive increase of the α-subunit mRNA levels. TNFα-treated Sertoli cells responded significantly to FSH and to (Bu)2cAMP, thus attenuating the inhibitory action of TNFα on the α-inhibin mRNA levels. Together, the present findings emphasize the ability of some local growth factors to modulate the effects of FSH on Sertoli cell function. Journal of Endocrinology (1995) 146, 501–508

scholarly journals Regulation of activin A and inhibin B secretion by inflammatory mediators in adult rat Sertoli cell cultures

2005 ◽  
Vol 187 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Y Okuma ◽  
A E O’Connor ◽  
J A Muir ◽  
P G Stanton ◽  
D M de Kretser ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Inflammatory Mediators ◽  
Sertoli Cells ◽  
Reproductive Function ◽  
Inhibitory Effect ◽  
Activin A ◽  
Inhibin B ◽  
Hormonal Stimulation ◽  
Adult Rat

The regulation of Sertoli cell activin A and inhibin B secretion during inflammation was investigated in vitro. Adult rat Sertoli cells were incubated with the inflammatory mediators, lipopolysaccharide (LPS), interleukin-1β (IL-1β), IL-6 and the IL-1 receptor antagonist (IL-1ra) over 48 h in culture. Activin A, inhibin B and IL-1α were measured in the culture medium by specific two-site ELISAs. Both IL-1β- and LPS-stimulated activin A and inhibited inhibin B secretion. LPS also stimulated the production of IL-1α in the cultures. In contrast to IL-1β, IL-6 had no effect on activin A, although it did have a significant inhibitory effect on inhibin B secretion. Ovine follicle-stimulating hormone (FSH) and the cAMP analogue dibutyryl cAMP opposed the actions of IL-1 and LPS by suppressing activin A and IL-1α secretion and by stimulating inhibin B. Blocking IL-1 activity in the cultures by addition of an excess of IL-1ra completely prevented the response of activin A to exogenous IL-1β, and reduced the response to LPS by 50%. In the presence of IL-1ra, basal secretion of inhibin B was increased, but IL-1ra was unable to reverse the suppression of inhibin B by LPS. These data indicate the importance of both IL-1 isoforms in regulating secretion of activin A and inhibin B by mature Sertoli cells during inflammation. The data also establish that inflammation exerts its effects on activin A and inhibin B secretion via other pathways in addition to those mediated by IL-1, and that hormonal stimulation by FSH and cAMP moderates the Sertoli cell response to inflammation. Interference with the complex interactions between these cytokines and hormones may contribute to the disruption of reproductive function that can accompany infection and illness in men.

scholarly journals Influence of mutations affecting gonadotropin production or responsiveness on expression of inhibin subunit mRNA and protein in the mouse ovary

Reproduction ◽  
2004 ◽  
Vol 128 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Rachel C Hirst ◽  
Margaret H Abel ◽  
Vivienne Wilkins ◽  
Christine Simpson ◽  
Phil G Knight ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Follicular Development ◽  
Inhibin B ◽  
Mrna Levels ◽  
Gene Encoding ◽  
Α Subunit ◽  
Lh Receptor ◽  
Protein Levels ◽  
Subunit Mrna ◽  
Major Cell Type

Measurement of inhibins A and B in the serum of normal cyclic rodents has implicated FSH in the regulation of these peptides within the ovary. To extend these observations we have used a panel of mutant mice carrying mutations which affect either the production of, or the ability to respond to, FSH and LH. As a consequence, the females are infertile and show different degrees of follicular development. The aim of this study was to measure inhibin gene transcription in the ovaries of these mutant females together with inhibin protein levels in ovaries and serum and to relate these to follicular development within the ovary. Comparison was made with a pool of normal/heterozygous females. In hpg females where lack of GnRH production results in the absence of gonadotropin synthesis, in FSHβ knockout (FSHβKO) females where disruption of the gene encoding FSHβ results in the absence of FSH production, and in FSH receptor knockout (FSHRKO) females which are unable to respond to circulating FSH, follicular development remains at the pre-antral stage in these three mutants. Only in the hpg females were common inhibin α subunit mRNA levels significantly lower than normal. In these three mutants, however, mRNA levels for both the βA and βB subunits were extremely low compared with normal mice. At the protein level, neither inhibin A nor B was detected in the serum of these three mutants; however inhibin B, albeit at very low levels, was detectable within the ovaries. These observations confirm a major role for FSH in the control of transcription of the βA and βB genes but suggest that the constitutive transcription of the alpha subunit is less dependent on FSH. In contrast, in LH receptor knockout (LuRKO) female mice inhibin βA subunit mRNA levels were similar to those measured in normal/heterozygous females but levels of inhibin α and βB subunit mRNAs were significantly higher than in the normal group. This was reflected in significantly higher inhibin B protein levels in ovaries and serum. An inability to respond to LH combined with high circulating levels of FSH leads to a high proportion of antral follicles in LuRKO females, with granulosa cells constituting the major cell type within the ovary. The high percentage of antral granulosa cells is likely to account for the significantly higher levels of inhibin B production in these ovaries.

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