scholarly journals Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Takashi Shimizu ◽  
Izumi Ohshima ◽  
Manabu Ozawa ◽  
Satoko Takahashi ◽  
Atsushi Tajima ◽  
...  
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Receptor Expression ◽  
Female Rats ◽  
Aromatase Activity ◽  
Mrna Levels ◽  
Gonadotropin Receptor ◽  
Estradiol Levels

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 °C, 50% RH; heat stress: 35 °C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.

P–139 The role of hormones and LH receptor expression of granulosa cells collected from large and small follicles in natural/minimal stimulation cycle IVF

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
T Okubo ◽  
H Teruaki ◽  
O Noriyuki ◽  
O Kenji ◽  
S Tomoya
Keyword(s):  
Mrna Expression ◽  
Granulosa Cells ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Lh Receptor ◽  
Small Follicle ◽  
Estradiol Levels ◽  
Natural Cycles ◽  
Follicular Fluids

Abstract Study question Do different follicle sizes influence gonadotropins (LH, FSH) and sex steroid (estradiol) in follicular fluids and LH receptor expression (LHCGR) in cumulus oocyte complexes (COCs)? Summary answer It was found that differences in levels of FSH, estradiol values and LHCGR mRNA expression level in COCs between small and large follicles. What is known already The maturity rate in oocytes of small follicle is significantly lower compared to that of large follicles. Study design, size, duration After obtaining written consents from 78 infertile patients, we aspirated the large (>15 mm) and small (<5 mm) follicles, and collected follicular fluids at oocyte retrieval. Participants/materials, setting, methods We measured levels of LH, FSH and estradiol by enzyme immunoassay from large and small follicular fluids after oocytes retrievals. All collected oocytes were distinguished from large and small follicles, we confirmed the maturity of retrieved oocytes by the presence of first polar body. Then we extracted total RNA from granulosa cells and measured mRNA expression of LHCGR, encoding the human LH receptor, by quantitative real-time PCR. Each value was normalized to ACTB mRNA levels. Main results and the role of chance LH levels were nearly equal between small and large follicles (P = 0.8356). Whereas FSH and estradiol levels were significantly lower in small follicles (P < 0.0001). The expression levels of LHCGR mRNA were significantly lower in small follicles than in large follicles during natural cycles. The maturity rate in oocytes of small follicle was significantly lower compared to that of large follicles (96.0% vs. 21.7%, P < 0001). Limitations, reasons for caution The main limitation of the present study was collected by 42 natural cycles and 36 mild stimulation cycles with letrozole following low-dose clomiphene. Wider implications of the findings: In spite of almost the same LH levels between two groups, the reason why the significantly lower maturation rates of oocytes collected from small follicles is poor LHCGR mRNA expression due to insufficient granulosa cells glowth because of low FSH and estradiol levels. Trial registration number Not applicable

Inhibition of LH-stimulated cyclic AMP formation in pre-ovulatory rat granulosa cells by follicular fluid

1980 ◽  
Vol 95 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Knut Nordenström ◽  
Anita Sjögren ◽  
Lars Hamberger
Keyword(s):  
Granulosa Cells ◽  
Follicular Fluid ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Bicarbonate Buffer ◽  
Ovulatory Follicles

Abstract. Immature female rats were injected sc with a single dose of PMSG to induce growth and maturation of ovarian follicles. In the morning of prooestrus the rats were given a single ip injection of LH (10 μg/rat) or 0.154 m NaCl, 2 h prior to sacrifice. Granulosa cells were isolated from the pre-ovulatory follicles and incubated in Krebs bicarbonate buffer, for 1 h with or without in vitro addition of various test substances. Following incubation the amounts of cAMP in tissue plus medium were determined. It was found that the isolated granulosa cells exposed to LH in vivo responded to the addition of LH in vitro with a production of high amounts of cAMP, i.e. these cells were not refractory to LH stimulation and in fact responded better than granulosa cells isolated from ovaries not exposed to LH in vivo. The addition to the incubation medium of follicular fluid (FFl) obtained from pre-ovulatory follicles decreased the effect of LH in vitro when added at a final concentration of 1% and completely abolished it at a concentration of 3%. Removal of steroids from the FFl did not influence the inhibitory effect and the addition of a phosphodiesterase inhibitor (IBMX) in vitro did not alter the results in principle. These results point to the existence of a factor in the FF1 which interacts with the sensitivity of the isolated preovulatory granulosa cells to repeated exposures to LH. Characterization of this factor is subject to further investigations.

509. REGULATING MURINE FOLLICLE DEVELOPMENT BY STIMULATION OF THE JAK2/STAT3 SIGNAL TRANSDUCTION PATHWAY

2009 ◽  
Vol 21 (9) ◽  
pp. 108
Author(s):  
R. A. Keightley ◽  
B. Nixon ◽  
S. D. Roman ◽  
D. L. Russell ◽  
R. L. Robker ◽  
...  
Keyword(s):  
Significant Role ◽  
Granulosa Cells ◽  
Ovarian Follicle ◽  
Expression Patterns ◽  
Follicular Development ◽  
Janus Kinase ◽  
Follicle Development ◽  
Mrna Levels ◽  
Primordial Follicles ◽  
Stat3 Signalling

Follicular development requires the recruitment of primordial follicles into the growing follicle pool following initiation of multiple cytokine signalling pathways. Suppression of follicular development is thought to be key to maintaining the population of primordial follicles and allowing for controlled release of these follicles throughout the reproductive lifespan of the female. However, little is known of the processes and signalling molecules that suppress primordial follicle activation and early follicle growth. Our group has identified significant upregulation of the Janus Kinase 2 (JAK2)/ Signal Transducer and Activator of Transcription 3 (STAT3) signalling pathway inhibitor the Suppressor of Cytokine Signalling 4 (SOCS4) that coincides with the initial wave of follicular activation in theneonatal mouse ovary. Further studies by our group have localised the SOCS4 protein to the granulosa cells of activating and growing follicles, suggesting SOCS4 expression may be linked to follicular activation. We have focused on examining protein localisation and gene expression patterns of the eight SOCS family members CIS and SOCS1-7. We have recently demonstrated that co-culture of neonatal ovaries with Kit Ligand (KL) for 2 days increases the mRNA levels of all SOCS genes. We also demonstrated the co-localisation of SOCS2 proteins with the KL receptor c-kit in the mural granulosa cells of antral, and large pre-antral follicles suggesting a significant role for SOCS2 in the later stages of follicular development. We have also shown that culturing ovaries with the potent JAK2 inhibitor AG490 substantially reduces mRNA levels of all SOCS and STAT genes that we have so far measured. We hypothesise a significant role for JAK2/STAT3 signalling in promoting the activation and early growth of ovarian follicles. Our investigations have identified significant roles for JAK2/STAT3 and the SOCS family in the regulation of ovarian follicle development.

scholarly journals Delayed effect of heat stress on steroid production in medium-sized and preovulatory bovine follicles

Reproduction ◽  
2001 ◽  
pp. 745-751 ◽  
Author(s):  
Z Roth ◽  
R Meidan ◽  
A Shaham-Albalancy ◽  
R Braw-Tal ◽  
D Wolfenson
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Heat Exposure ◽  
Low Fertility ◽  
Delayed Effect ◽  
Steroid Production ◽  
Thecal Cells ◽  
Preovulatory Follicles ◽  
Subsequent Cycle

During the autumn, the conception rate of dairy cattle in warm countries is low although ambient temperatures have decreased and cows are no longer exposed to summer thermal stress, indicating that there may be a delayed effect of heat stress on cattle fertility. Two experiments were conducted to examine possible delayed effects of heat stress on follicular characteristics and steroid production at two distinct stages of follicular growth: medium-sized and preovulatory follicles, 20 and 26 days after heat exposure, respectively. Lactating cows were subjected to heat stress for 12 h a day in an environmental chamber, during days 2-6 of a synchronized oestrous cycle. In Expt 1, ovaries were collected on day 3 of the subsequent cycle, before selection of the dominant follicle, and medium-sized follicles were classified as atretic or healthy. In Expt 2, on day 7 of the subsequent cycle, PGF(2a) was administered and preovulatory follicles were collected 40 h later. In both experiments, follicular fluid was aspirated, granulosa and thecal cells were incubated, and steroid production was determined. In healthy medium-sized follicles (Expt 1), oestradiol production by granulosa cells and androstenedione production by thecal cells were lower (P < 0.05) and the concentration of progesterone in the follicular fluid was higher in cows that had been previously heat-stressed than in control cows (P < 0.05). In preovulatory follicles (Expt 2), the viability of granulosa cells was lower (P < 0.05) and the concentration of androstenedione in the follicular fluid and its production by thecal cells were lower (P < 0.05) in cows that had been previously heat-stressed than in control cows. In both experiments, the oestradiol concentrations in the follicular fluids were not altered by heat stress. These results demonstrate a delayed effect of heat stress on steroid production and follicular characteristics in both medium-sized and preovulatory follicles; this effect could be related to the low fertility of cattle in the autumn.

scholarly journals Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles

Reproduction ◽  
2010 ◽  
Vol 139 (5) ◽  
pp. 871-881 ◽  
Author(s):  
Catherine M H Combelles ◽  
Emily A Holick ◽  
Louis J Paolella ◽  
David C Walker ◽  
Qiaqia Wu
Keyword(s):  
Superoxide Dismutase ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Antral Follicle ◽  
Supporting Evidence ◽  
Sod Activity ◽  
Antral Follicles ◽  
Sod Isoforms

The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis.

Oocyte-secreted factros regulate granulosa cell steroidogenesis

Zygote ◽  
1996 ◽  
Vol 4 (04) ◽  
pp. 317-321 ◽  
Author(s):  
Barbara C. Vanderhyden
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Inhibitory Factor ◽  
Preovulatory Follicles ◽  
Loss Of Contact

Investigations of strains of mice defective in germ cell development have revealed the importance of oocytes for the initial stages of folliculogenesis (Pellaset al., 1991; Huanget al., 1993). Various aspects of follicular development are dependent upon and/or influenced by the presence of oocytes, including granulosa cell proliferation (Vanderhydenet al., 1990, 1992) and cumulus expansion (Buccioneet al., 1990; Salustriet al., 1990; Vanderhydenet al., 1990; Vanderhyden, 1993). We are investigating the possibility that oocytes influence one of the primary functions of granulosa cells: steroidogenesis. In many species, granulosa cells removed from preovulatory follicles luteinisein vitro(Channinget al., 1982), presumably due to loss of contact with follicular luteinisation inhibitory factor(s). Indeed, follicular fluid can prevent granulosa cell luteinisationin vitro(Ledwitz-Rigbyet al., 1977). Follicular fluid, however, may simply be the medium for transport of factors secreted by oocytes to regulate granulosa cell activities.

187 EXPRESSION AND REGULATION OF THE FIBROBLAST GROWTH FACTOR GENE FAMILY DURING MOUSE FOLLICULAR DEVELOPMENT

2013 ◽  
Vol 25 (1) ◽  
pp. 243
Author(s):  
S. Furukawa ◽  
K. Naito ◽  
K. Sugiura
Keyword(s):  
Gene Family ◽  
Granulosa Cells ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Mrna Levels ◽  
Fibroblast Growth ◽  
Mouse Ovary ◽  
Expression Levels ◽  
Before And After ◽  
Equine Chorionic Gonadotropin

Recent studies have shown the critical roles of fibroblast growth factors (FGFs), including FGF8 produced by oocytes, in regulating follicular development. However, the expression and regulation of the FGF gene family, which consists of 22 ligands and 4 receptors, in the mouse ovary have not been well understood. The aim of the present study was to assess the expression and regulation of FGF ligands and receptors in the mouse ovary. Transcript levels of FGF ligands and receptors in immature (3-week-old) and adult (7- to 8-week-old) ovaries as well as other tissues of B6/DBA2F1 mice were analysed with RT-PCR. Furthermore, expression levels of FGF receptors in cumulus cells (CC) and mural granulosa cells (MG) before and after equine chorionic gonadotropin (eCG) treatment were determined with RT-quantitative PCR. Among 21 FGF ligands examined, 12 and 9 transcripts were detectable in immature and adult ovaries, respectively. More FGF ligands were detected in ovary, testis, heart, and brain compared to other tissues, including liver and spleen. Transcripts of all 4 FGF receptors (Fgfr1–4) were detectable in both immature and adult ovaries. Expression levels of Fgfr1 and Fgfr2 were significantly higher in MG compared with CC before and after the eCG treatment. Levels of Fgfr4 were comparable between MG and CC before the eCG treatment, but became significantly different with higher expression levels in MG after the eCG treatment. Fgfr3 transcripts were barely detectable in CC and MG. Overall levels of Fgfr1 in granulosa cells (CC and MG) were downregulated by eCG treatment, whereas those of Fgfr2 and Fgfr4 were upregulated. In summary, many FGF ligands are expressed, at least in mRNA levels, in mouse ovaries. Moreover, the expression levels of Fgfr transcripts in granulosa cells are dynamically regulated during follicular development.

Sign in / Sign up

Export Citation Format

Share Document