Expression of steroid receptors, their cofactors, and aromatase in human luteinized granulosa cells after controlled ovarian hyperstimulation

Analysis of androgen receptor and anti-Müllerian hormone pathways in human granulosa cells under luteinizing hormone treatment

BACKGROUND

The objective of this study was to determine the gene expression profiles of the androgen/androgen receptor (AR) and anti-Müllerian hormone (AMH)/ Sry-related high-mobility group box 9 (SOX9) pathways in granulosa-luteal cells from patients undergoing standard in vitro fertilization (IVF) with or without recombinant luteinizing hormone (rLH) therapy.

METHODS

Levels of reproductive hormones in the pre-ovulatory follicular fluid and the expression levels of LHR (luteinizing hormone receptor), AR, SOX9, AMH, AR-associated protein 54(ARA54)and ARA70 were determined in granulosa-luteal cells by real-time reverse-transcription PCR. The effects of androgen and rLH treatments on AR and AMH expression levels were also tested in vitro using HO23 cells.

RESULTS

We collected 35 an 70 granulosa cell samples from patients cycled with and without rLH supplementation, respectively. The clinical outcomes were similar in patients who received rLH therapy and those who did not, though the pre-ovulatory follicular fluid levels of androstenedione, testosterone, and estradiol were significantly higher and progesterone was lower in the rLH supplementation group. Moreover, granulosa-luteal cell mRNA levels of LHR, AR, AMH, and SOX9 were significantly higher in the rLH supplementation group relative to the group that did not receive rLH supplementation. In addition, we observed significant correlations between LHR and AR mRNA expression and among AR, AMH, and SOX9 mRNA expression in granulosa-luteal cells from patients undergoing standard IVF treatment.

CONCLUSIONS

Increased expression of LHR, AR, AMH, and SOX9 is characteristic of granulosa-luteal cells from IVF/ intracytoplasmic sperm injection (ICSI) patients receiving rLH supplementation.

FSH receptor in vitro modulation by testosterone and hCG in human luteinized granulosa cells

OBJECTIVE

To investigate the effect of testosterone and hCG on FSH receptor (FSHR) protein and mRNA expression in human granulosa cells (GC) in vitro.

STUDY DESIGN

Experimental in vitro cell culture obtained from healthy women undergoing IVF/ICSI due to male factor infertility. Human follicular fluid samples were obtained and after cumulus-oocyte complexes were identified, fluids were pipetted onto Ficoll gradients and centrifuged for 15 min at 400 × g at room temperature. Cells at the interface were removed and plated in 24-well plates for 3 days in M-199 with 10% FBS. Cells were treated with different concentrations of testosterone and hCG. After purification, cells were labeled with specific antibodies and the protein expression of the FSHR was evaluated by flow cytometry in the GC population. Also, total RNA was extracted from confluent GC and the FSHR gene expression was evaluated by RT-PCR.

RESULTS

FSHR expression was modulated by treating GC in vitro at different testosterone/hCG concentrations. When compared with untreated GC, we observed a significant effect of testosterone and hCG on the expression of the FSHR at the protein level. Time course experiments confirmed that the gene expression of the FSHR peaked at 12-24h when testosterone or hCG was used as a stimulus.

CONCLUSIONS

Both testosterone and hCG are able to positively modulate FSHR expression at gene and protein level in human GC in vitro.

Expression and function of nuclear receptor co-activator 4: evidence of a potential role independent of co-activator activity

Nuclear receptor coactivator 4 (NcoA4), also known as androgen receptor-associated protein 70 (ARA70), was initially discovered as a component of Ret-Fused Gene expressed in a subset of papillary thyroid carcinomas. Subsequent studies have established NcoA4 as a coactivator for a variety of nuclear receptors, including peroxisome proliferator activated receptors α and γ, and receptors for steroid hormones, vitamins D and A, thyroid hormone, and aryl hydrocarbons. While human NcoA4 has both LXXLL and FXXLF motifs that mediate p160 coactivator nuclear receptor interactions, this ubiquitously expressed protein lacks clearly defined functional domains. Several studies indicate that NcoA4 localizes predominantly to the cytoplasm and affects ligand-binding specificity of the androgen receptor, which has important implications for androgen-independent prostate cancer. Two NcoA4 variants, which may exert differential activities, have been identified in humans. Recent studies suggest that NcoA4 may play a role in development, carcinogenesis, inflammation, erythrogenesis, and cell cycle progression that may be independent of its role as a receptor coactivator. This review summarizes what is currently known of the structure, expression, regulation, and potential functions of this unique protein in cancerous and non-cancerous pathologies.

Endometriosis does not Alter Aromatase Gene Expression (CYP19A1) in Mural Lutein-granulosa Cells of Women Undergoing Assisted Reproduction Techniques – a Pilot Study

Purpose

The aim of this study was to quantify aromatase gene expression in mural lutein-granulosa cells of women with endometriosis undergoing assisted reproduction techniques (ART, IVF or ICSI). Methods: a case-control study was performed on 11 women with endometriosis (all stages, ASRM criteria) and 11 women with male or tubal causes of infertility undergoing ART. There was no difference between the groups regarding age, amount of gonadotrophins used, days of induction, follicles, and eggs collected. Mural lutein-granulosa cells were harvested from pre-ovulatory follicles during oocyte retrieval and correctly isolated. After cells lyses and storage into Trizol LS Reagent®, RNA extraction and cDNA synthesis were performed. Quantification of relative gene expression for CYP19A1 (aromatase) was performed by real time PCR, using SYBR Green reagents. All experiments were performed in duplicates.

Results

there was no difference between the groups in the quantitative gene expression of CYP19A1 (aromatase) gene on mural lutein-granulosa cells (P>.05, Mann Whitney).

Conclusions

These results suggest that this enzyme, aromatase, may have a complex and refined control of its gene expression on this population of granulosa cells, and in spite of previous evidence showing its reduced activity on these cells in endometriosis, gene expression per se may not be affected by the disease.

In vitro effect of dehydroepiandrosterone sulfate on steroid receptors, aromatase, cyclooxygenase-2 expression, and steroid hormone production in preovulatory human granulosa cells

OBJECTIVE

To examine the effect of a low concentration of DHEAS on the expression of the androgen receptor, estrogen receptor alpha and beta, progesterone receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2 in human preovulatory granulosa cells, and to measure their production of steroid hormones (estrone, estradiol, progesterone, androstenedione, and testosterone).

DESIGN

Analysis of cultured primary human preovulatory granulosa cells by real-time reverse-transcriptase polymerase chain reaction and assays of hormone production.

SETTING

Osaka City University Postgraduate School of Medicine.

INTERVENTION(S)

Preovulatory granulosa cells were collected from follicular fluid obtained from patients undergoing transvaginal oocyte retrieval with ultrasound guidance. The cells were cultured in the absence or presence of a low concentration of DHEAS. Real-time reverse-transcriptase polymerase chain reaction was performed to quantify the RNA expression of the investigated genes, and steroid hormone (estrone, estradiol, progesterone, androstenedione, and testosterone) levels were measured in the culture medium.

MAIN OUTCOME MEASURE(S)

Changes in [1] the levels of mRNAs encoding androgen receptor, estrogen receptor alpha, estrogen receptor beta, progesterone receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2; and [2] the levels of steroid hormones (estrone, estradiol, progesterone, androstenedione, and testosterone) in the culture medium.

RESULT(S)

Treatment of granulosa cells with 20 ng/mL DHEAS increased the expression of androgen receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2, reduced the expression of estrogen receptor beta, and increased estrone and estradiol levels, but had no effect on progesterone, androstenedione, or testosterone levels.

CONCLUSION(S)

DHEAS may be an essential trigger of ovulation.

Molecular mechanisms of ovulation: co-ordination through the cumulus complex

Successful ovulation requires that developmentally competent oocytes are released with appropriate timing from the ovarian follicle. Somatic cells of the follicle sense the ovulatory stimulus and guide resumption of meiosis and release of the oocyte, as well as structural remodelling and luteinization of the follicle. Complex intercellular communication co-ordinates critical stages of oocyte maturation and links this process with release from the follicle. To achieve these outcomes, ovulation is controlled through multiple inputs, including endocrine hormones, immune and metabolic signals, as well as intrafollicular paracrine factors from the theca, mural and cumulus granulosa cells and the oocyte itself. This review focuses on the recent advances in understanding of molecular mechanisms that commence after the gonadotrophin surge and culminate with release of the oocyte. These mechanisms include intracellular signalling, gene regulation and remodelling of tissue structure in each of the distinct ovarian compartments. Most critical ovulatory mediators exert effects through the cumulus cell complex that surrounds and connects with the oocyte. The convergence of ovulatory signals through the cumulus complex co-ordinates the key mechanistic processes that mediate and control oocyte maturation and ovulation.

Expression of inhibin-activin subunits, follistatin and smads in granulosa-luteal cells collected at oocyte retrieval

PURPOSE

To examine the expression of inhibin-activin subunits, follistatin, and Smads 2, 3 and 4 in granulosa-luteal cells at the time of oocyte retrieval.

METHODS

Quantitative reverse transcriptase-polymerase chain reaction was performed to quantify the mRNA expression of the investigated genes: inhibin alpha-subunit, inhibin-activin betaA- and betaB-subunits, follistatin, and Smads 2, 3 and 4.

RESULTS

alpha-, betaA- and betaB-subunits of inhibin-activin, and follistatin were all well expressed in granulosa-luteal cells obtained from either dominant or cohort follicles. alpha-subunits strongly correlated with Smad2 (p < 0.001). betaA-subunit significantly correlated with Smad4, p < 0.001. betaB-subunit significantly correlated with Smad2, p = 0.002, and follistatin expression strongly correlated with the expression of Smads 2 and 4 (p < 0.001 and = 0.007 respectively).

CONCLUSIONS

We found, for the first time that inhibin-activin betaB-subunit mRNA was well expressed in human granulosa-luteal cells obtained from either dominant or cohort follicles. alpha-, betaA- and betaB-subunits and follistatin correlated with Smads to varied degrees, suggesting the active roles of the above genes at the time of oocyte retrieval.