Effects of testosterone, dihydrotestosterone, and 17β-estradiol on human ovarian tissue survival in culture

Liver Receptor homolog-1 Regulates Apoptosis of Bovine Ovarian Granulosa Cells by Progestogen Receptor Signaling Pathway

The purpose of the present investigation was to assess the function of LRH-1 on GCs and the mechanisms involved. Here, LRH- was highly expressed in the bovine GCs of atretic follicles. Treatment with 50 μM of LRH-1 agonist (DLPC) significantly induced the expression of LRH-1 (p < 0.05). In particular, LRH-1 activation blocked the progestogen receptor signaling pathway via downregulating progesterone production and progestogen receptor levels (p < 0.05), but had no effect on 17 beta-estradiol synthesis. Meanwhile, LRH-1 activation promoted the apoptosis of GCs and increased the activity of caspase 3 (p < 0.05). Importantly, upregulating the progestogen receptor signaling pathway with progestogen could attenuate the LRH-1-induced proapoptotic effect. Moreover, treatment with progestogen decreased the activity of the proapoptotic gene caspase 3 and increased the expression of antiapoptotic gene Bcl2 in LRH-1 activated GCs (p < 0.05). Taken together, these results demonstrate that LRH-1 might be dependent on the progestogen receptor signaling pathway to modulate bovine follicular atresia.

Ligand Binding Prolongs Androgen Receptor Protein Half-Life by Reducing its Degradation

Androgens are important in female reproduction, but the molecular actions of androgens in female reproductive tissues are not fully understood. We investigated the androgen-responsive transcriptome in human and mouse granulosa cells (GCs) and surprisingly found that the gene-regulation activity of androgen receptor (AR) in these cells is negligible. We then investigated extranuclear actions of AR and found that in human and mouse GCs, as well as in prostate cancer cells, dihydrotestosterone (DHT) dramatically increases the half-life of its own receptor protein. Using the human granulosa-like KGN cells, we show that this effect is not the result of increased AR gene transcription or protein synthesis, nor is it fully abrogated by proteasome inhibition. Knockdown of PTEN, which contributes to degradation of cytoplasmic AR, did not diminish AR accumulation in the presence of DHT. Using immunofluorescence cellular localization studies, we show that nuclear AR is selectively protected from degradation in the presence of DHT. Knockdown of importin 7 expression, a potential regulator of AR nuclear import, does not affect DHT-mediated nuclear accumulation of AR, suggesting importin 7-independent nuclear import of AR in GCs. Further, DNA binding is not required for this protective mechanism. In summary, we show that ligand binding sequesters AR in the nucleus through enhanced nuclear localization independent of DNA binding, thereby protecting it from proteasome degradation in the cytoplasm. This phenomenon distinguishes AR from other sex steroid receptors and may have physiological significance through a positive feedback loop in which androgen induces its own activity in male and female reproductive tissues.

Applicability of Hyaluronic Acid-Alginate Hydrogel and Ovarian Cells for In Vitro Development of Mouse Preantral Follicles

Objective

In the present study, the applicability of hyaluronic acid-alginate (HAA) hydrogel and ovarian cells (OCs) for the culture of mouse ovarian follicles were investigated and compared with those of alginate (ALG) and fibrin-alginate (FA) hydrogels.

Materials and Methods

In the first step of this experimental study, mechanically isolated preantral follicles from the ovaries of two-week-old mice were encapsulated in the absence or presence of OCs in ALG, HAA, and FA hydrogels and cultured for 14 days. The morphology, diameter, survival and antrum formation rates of the follicles and the maturation and quality of the oocytes were evaluated during culture. In the second step, preantral follicles were cultured similar to the first step, but for 13 days, and their gene expressions and hormonal secretion were assessed on the last day of culture.

Results

In the absence of OCs, higher numbers of ALG- and HAA-encapsulated follicles reached the antral stage compared to FA-encapsulated follicles (P<0.05). However, a higher percentage of HAA-developed oocytes resumed meiosis up to the germinal vesicle breakdown (GVBD)/metaphase II (MII) stages in comparison with ALG-developed oocytes (P<0.05). HAA-encapsulated follicles had significant overexpression of most of the growth and differentiation genes, and secreted higher levels of estradiol (E2) compared to ALG- and FA-encapsulated follicles (P<0.05). The co-culture condition increased the diameter of ALG-encapsulated follicles on day 13 of culture (P<0.05). It also increased the survival and maturation rates of ALG- and FA-encapsulated follicles, respectively (P<0.05). The co-culture condition improved cortical granule distribution in all groups, increased E2 and progesterone (P4) secretions in the ALG and FA groups, and androstenedione (A4) secretion in the FA group (P<0.05).

Conclusion

The present study results show that HAA hydrogel is a promising hydrogel for follicle culture. OCs utilization could ameliorate the culture conditions regardless of the type of hydrogel.

Androgen effect on connexin expression in the mammalian female reproductive system: A systematic review

The functions of androgen and connexin in the mammalian female reproductive system are suggested to be related. Previous research has shown that androgen affects connexin expression in the female reproductive system, altering its function. However, no definitive conclusion on their cause-effect relationship has been drawn yet. In addition, a high prevalence of women with polycystic ovary syndrome (PCOS), who are characterized by elevated androgen levels and failure of ovulation, has prompted the studies on the relationship between androgen and connexin in the ovaries. This systematic review aims to investigate the effect of androgen on connexin expression in the mammalian female reproductive system. The literature search was conducted using the MEDLINE via EBSCOhost and the Scopus database and the following keywords: “androgen” or “testosterone” or “androgen blocker” or “anti-androgen” or “androstenedione” or “dehydroepiandrosterone” or “flutamide AND connexin” or “gap junction” or “cell junction”. We only considered in vitro and in vivo studies that involved treatment by androgen or androgen receptor blockers and measured connexin expression as one of the parameters. Our review showed that the exposure to androgen or androgen blocker affects connexin expression but not its localization in the mammalian ovary. However, it is not clear whether androgen downregulates or upregulates connexin expression.

Physiological and Pathological Androgen Actions in the Ovary

Androgens, although traditionally thought to be male sex steroids, play important roles in female reproduction, both in healthy and pathological states. This mini-review focuses on recent advances in our knowledge of the role of androgens in the ovary. Androgen receptor (AR) is expressed in oocytes, granulosa cells, and theca cells, and is temporally regulated during follicular development. Mouse knockout studies have shown that AR expression in granulosa cells is critical for normal follicular development and subsequent ovulation. In addition, androgens are involved in regulating dynamic changes in ovarian steroidogenesis that are critical for normal cycling. Androgen effects on follicle development have been incorporated into clinical practice in women with diminished ovarian reserve, albeit with limited success in available literature. At the other extreme, androgen excess leads to disordered follicle development and anovulatory infertility known as polycystic ovary syndrome (PCOS), with studies suggesting that theca cell AR may mediate many of these negative effects. Finally, both prenatal and postnatal animal models of androgen excess have been developed and are being used to study the pathophysiology of PCOS both within the ovary and with regard to overall metabolic health. Taken together, current scientific consensus is that a careful balance of androgen activity in the ovary is necessary for reproductive health in women.

Inhibitors of c-Jun phosphorylation impede ovine primordial follicle activation

STUDY HYPOTHESIS

Is the c-Jun-N-terminal kinase (JNK) pathway implicated in primordial follicle activation?

STUDY FINDING

Culture of ovine ovarian cortex in the presence of two different c-Jun phosphorylation inhibitors impeded pre-antral follicle activation.

WHAT IS KNOWN ALREADY

Despite its importance for fertility preservation therapies, the mechanisms of primordial follicle activation are poorly understood. Amongst different signalling pathways potentially involved, the JNK pathway has been previously shown to be essential for cell cycle progression and pre-antral follicle development in mice.

STUDY DESIGN, SAMPLES/MATERIALS, METHODS

Ovine ovarian cortex pieces were cultured with varying concentrations of SP600125, JNK inhibitor VIII or anti-Mullerian hormone (AMH) in the presence of FSH for 9 days. Follicular morphometry and immunohistochemistry for proliferating cell nuclear antigen (PCNA), apoptosis and follicle activation (Foxo3a) were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

Inhibition of primordial follicle activation occurred in the presence of SP600125, JNK inhibitor VIII and AMH when compared with controls (all P < 0.05) after 2 days of culture. However, only in the highest concentrations used was the inhibition of activation associated with induction of follicular apoptosis (P < 0.05). In growing follicles, PCNA antigen expression was reduced when the JNK inhibitors or AMH were used (P < 0.05 versus control), indicating reduced proliferation of the somatic compartment.

LIMITATIONS, REASONS FOR CAUTION

Although we evaluated the effects of inhibition of c-Jun phosphorylation on primordial follicle development, we did not determine the cellular targets and mechanism of action of the inhibitors.

WIDER IMPLICATIONS OF THE FINDINGS

These results are the first to implicate the JNK pathway in primordial follicle activation and could have significant consequences for the successful development of fertility preservation strategies and our understanding of primordial follicle activation.

LARGE SCALE DATA

n/a.

STUDY FUNDING AND COMPETING INTERESTS

Dr Michael J. Bertoldo and the laboratories involved in the present study were supported by a grant from 'Région Centre' (CRYOVAIRE, Grant number #320000268). There are no conflicts of interest to declare.

Effects of dehydroepiandrosterone supplementation on women with poor ovarian response: A preliminary report and review

OBJECTIVE

To investigate the effect of dehydroepiandrosterone (DHEA) supplementation on women with poor ovarian response (POR).

MATERIALS AND METHODS

Women with POR treated with flexible daily gonadotropin-releasing hormone antagonist in vitro fertilization (IVF) cycles at The Reproductive Center in Kaohsiung Veterans General Hospital between January 2013 and October 2013, were enrolled for this prospective study. When patients failed to become pregnant during the first IVF cycle, they were treated with DHEA supplementation (30 mg, 3 times a day, orally) for 3 months (mean 12.2 weeks) before the next IVF cycle. Parameters of biochemical, ultrasound and treatment outcomes were compared before and after DHEA supplementation.

RESULTS

Ten patients with a mean age of 36.6 ± 4.2 years were identified. After DHEA treatment, there was a significant increase in antral follicle count, from 2.8 ± 1.0 to 4.1 ± 1.2 (p < 0.05), and anti-Müllerian hormone, from 0.4 ± 0.2 ng/mL to 0.84 ± 0.2 ng/mL (p < 0.001). A significant decrease of Day 3 follicle-stimulating hormone and estradiol, from 14.4 ± 1.7 mIU/mL to 10.1 ± 0.7 mIU/mL and from 51.2 ± 6.3 pg/mL to 35.2 ± 4.2 pg/mL, respectively (both p < 0.001), was noted. Increased numbers of retrieved oocytes (from 2.4 ± 1.1 to 4.2 ± 1.2; p < 0.01), fertilized oocytes (from 1.7 ± 0.5 to 3.8 ± 1.1; p < 0.001), Day 3 embryos (from 1.7 ± 0.5 to 3.7 ± 1.1; p < 0.001) and transferred embryos (from 1.7 ± 0.8 to 2.8 ± 0.8; p < 0.01) were also seen in these women with POR after DHEA treatment. Three women became pregnant after DHEA treatment.

CONCLUSION

The potential benefits of DHEA supplementation in women with POR were suggested by the biochemical parameters and IVF outcomes.

Gene expression of cumulus cells in women with poor ovarian response after dehydroepiandrosterone supplementation

OBJECTIVE

Our previous study showed the potential benefits of dehydroepiandrosterone (DHEA) supplementation in women with a poor ovarian response (POR). Because the connection between cumulus cells (CCs) and oocytes is a key step for oocyte maturation, we supposed that altered gene expression of CCs in women with POR after DHEA supplementation might favor oocyte maturation.

MATERIALS AND METHODS

Women with POR treated with flexible daily gonadotropin-releasing hormone antagonist in vitro fertilization (IVF) cycles at The Reproductive Center in Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan between January 2013 and October 2013 were enrolled for this prospective study. CCs were isolated during IVF before and after DHEA (CPH-Formulation, Oakdale, CA, USA) supplementation. Nine genes of isolated CCs, including hyaluronan synthase (HAS2), versican (VCAN), thrombospondin 1 (THBS1), runt-related transcription factor 2 (RUNX2), chromobox homolog 3 (CBX3), tripartite motif-containing 28 (TRIM28), B-cell lymphoma 2 (BCL2), BCL2-associated X protein (BAX), and ankyrin repeat domain 57 (ANKRD57), were compared.

RESULTS

There was a significant difference in the expression of genes in women with POR before and after DHEA supplementation (all p < 0.05). All genes related to extracellular matrix (ECM) formation, including HAS2, VCAN, and THBS1, were upregulated. By contrast, all genes involving cell development, differentiation, and apoptosis regulation were downregulated. Unknown function gene ANKRD57 was also downregulated after DHEA supplementation. Although expressions of both BCL2 and BAX were decreased in women with POR after DHEA supplementation compared to those before treatment, the ratio of BCL2 and BAX was significantly increased in women with POR after DHEA supplementation, suggesting that DHEA supplementation might activate the antiapoptosis process of CCs, which might be beneficial to the improvement of ovarian function in women with POR.

CONCLUSION

The study showed that DHEA therapy positively affected the gene expression of CCs in women with POR, and provided evidence to support the positive effect of DHEA supplementation on women with POR.

1,25-Dihydroxyvitamin D3 increases testosterone-induced 17beta-estradiol secretion and reverses testosterone-reduced connexin 43 in rat granulosa cells

BACKGROUND

Aromatase converts testosterone into 17beta-estradiol in granulosa cells, and the converted 17beta-estradiol contributes to follicular maturation. Additionally, excessive testosterone inhibits aromatase activity, which can lead to concerns regarding polycystic ovary syndrome (PCOS). Generally, 1,25-dihydroxyvitamin D3 (1,25D3) supplements help to improve the symptoms of PCOS patients who exhibit low blood levels of 1,25D3. Therefore, this study investigated the interaction effects of 1,25D3 and testosterone on estrogenesis and intercellular connections in rat granulosa cells.

METHODS

Primary cultures of granulosa cells were treated with testosterone or testosterone plus 1,25D3, or pre-treated with a calcium channel blocker or calcium chelator. Cell lysates were subjected to western blot analysis to determine protein and phosphorylation levels, and 17beta-estradiol secretion was examined using a radioimmunoassay technique. Cell viability was evaluated by MTT reduction assay. Connexin 43 (Cx43) mRNA and protein expression levels were assessed by qRT-PCR, western blot, and immunocytochemistry.

RESULTS

Testosterone treatment (0.1 and 1 microg/mL) increased aromatase expression and 17beta-estradiol secretion, and the addition of 1,25D3 attenuated testosterone (1 microg/mL)-induced aromatase expression but improved testosterone-induced 17beta-estradiol secretion. Furthermore, testosterone-induced aromatase phosphotyrosine levels increased at 10 min, 30 min and 1 h, whereas 1,25D3 increased the longevity of the testosterone effect to 6 h and 24 h. Within 18-24 h of treatment, 1,25D3 markedly enhanced testosterone-induced 17beta-estradiol secretion. Additionally, pre-treatment with a calcium channel blocker nifedipine or an intracellular calcium chelator BAPTA-AM reduced 1,25D3 and testosterone-induced 17beta-estradiol secretion. Groups that underwent testosterone treatment exhibited significantly increased estradiol receptor beta expression levels, which were not affected by 1,25D3. Neither testosterone nor 1,25D3 altered 1,25D3 receptor expression. Finally, at high doses of testosterone, Cx43 protein expression was decreased in granulosa cells, and this effect was reversed by co-treatment with 1,25D3.

CONCLUSIONS

These data suggest that 1,25D3 potentially increases testosterone-induced 17beta-estradiol secretion by regulating aromatase phosphotyrosine levels, and calcium increase is involved in both 1,25D3 and testosterone-induced 17beta-estradiol secretion. 1,25D3 reverses the inhibitory effect of testosterone on Cx43 expression in granulosa cells.

Effects of 5α-dihydrotestosterone and 17β-estradiol on the mouse ovarian follicle development and oocyte maturation

We have previously reported that androstenedione induces abnormalities of follicle development and oocyte maturation in the mouse ovary. In granulosa cells of the ovarian follicle, androstenedione is aromatized to 17β-estradiol (E₂). To determine whether the androgen or estrogen acts directly on the follicle to induce the above-mentioned abnormalities, we compared the effects of a non-aromatizable androgen, 5α-dihydrotestosterone (DHT), with those of E₂ on murine follicular development and oocyte maturation in a single follicle culture system. The high dose (10⁻⁶ M) of DHT prompted normal follicular development, and there was no effect on oocyte meiotic maturation after stimulation with human chorionic gonadotropin (hCG) and epidermal growth factor (EGF). In contrast, culture with the high dose (10⁻⁶ M) of E₂ delayed follicular growth and also suppressed proliferation of granulosa cells and antrum formation. Furthermore, culture with E₂ delayed or inhibited oocyte meiotic maturation, such as chromosome alignment on the metaphase plate and extrusion of the first polar body, after addition of hCG and EGF. In conclusion, these findings demonstrate that E₂, but not DHT, induces abnormalities of follicular development, which leads to delay or inhibition of oocyte meiotic maturation.

Inhibition of phosphatase and tensin homologue (PTEN) in human ovary in vitro results in increased activation of primordial follicles but compromises development of growing follicles

In the mammalian ovary a small number of follicles are steadily recruited from the quiescent pool to undergo development. Follicle loss, maintenance and growth are strictly controlled by complex molecular interactions including the phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signalling pathway. Stimulation of PI3K promotes phosphorylation of Akt resulting in follicle survival and activation of growth whereas this pathway is suppressed by the actions of the phosphatase and tensin homologue (PTEN). The aim of this study was to determine the effect of dipotassium bisperoxo(5-hydroxypyridine-2-carboxyl)oxovanadate (bpV), a reversible inhibitor of PTEN, on the activation, survival and development of human ovarian follicles in vitro. Biopsied ovarian tissue fragments were obtained from 17 women aged 23-46 years and exposed to 1 µM bpV(HOpic) (n = 146) or control medium (n = 128) for 24 h. Media were then replaced with control medium and all tissue incubated for a further 5 days. Ovarian tissue from each treatment group was fixed after the initial 24 h culture period and phosphorylated Akt was quantified by western blotting. After 6 days incubation all tissue fragments were inspected under light microscopy and any secondary follicles ≥100 µm isolated. Isolated follicles were cultured individually in control medium supplemented with 100 ng/ml recombinant human activin A. Tissue fragments without follicles suitable for isolation were fixed and processed for histological and immunohistochemical analysis. During 6 days culture, follicle activation occurred in tissue samples from both treatment groups but with significantly more follicles progressing to the secondary stage of development in the presence of 1 µM bpV(HOpic) compared with control (31 versus 16%; P < 0.05). Increased activation was associated with increased Akt phosphorylation and increased nuclear export of FOXO3. However isolated and cultured follicles that had been exposed to bpV(HOpic) showed limited growth and reduced survival compared with follicles from control fragments (P < 0.05). This study demonstrates that inhibition of PTEN with bpV(HOpic) affects human ovarian follicle development by promoting the initiation of follicle growth and development to the secondary stage, as in rodent species, but severely compromises the survival of isolated secondary follicles.

The role of androgen hormones in early follicular development

Background. Although chronic hyperandrogenism, a typical feature of polycystic ovary syndrome, is often associated with disturbed reproductive performance, androgens have been shown to promote ovarian follicle growth in shorter exposures. Here, we review the main effects of androgens on the regulation of early folliculogenesis and the potential of their application in improving follicular in vitro growth. Review. Androgens may affect folliculogenesis directly via androgen receptors (ARs) or indirectly through aromatization to estrogen. ARs are highly expressed in the granulosa and theca cells of early stage follicles and slightly expressed in mature follicles. Short-term androgen exposure augments FSH receptor expression in the granulosa cells of developing follicles and enhances the FSH-induced cAMP formation necessary for the transcription of genes involved in the control of follicular cell proliferation and differentiation. AR activation also increases insulin-like growth factor (IGF-1) and its receptor gene expression in the granulosa and theca cells of growing follicles and in the oocytes of primordial follicles, thus facilitating IGF-1 actions in both follicular recruitment and subsequent development. Conclusion. During the early and intermediate stages of follicular maturation, locally produced androgens facilitate the transition of follicles from the dormant to the growing pool as well as their further development.

Maternal high-fat diet induces follicular atresia but does not affect fertility in adult rabbit offspring

Alterations to the metabolic environment in utero can have an impact on subsequent female reproductive performance. Here, we used a model of rabbits receiving a high-fat diet (H diet; 7.7% fat and 0.2% cholesterol) or a control diet (C diet; 1.8% fat, no cholesterol) from 10 weeks of age up to mating at 27 weeks and throughout gestation and lactation. At weaning at 5 weeks of age, F1 female offspring were placed on either C or H diet, resulting in a total of four groups C/C, C/H, H/C and H/H diet. Female offspring were mated between 18 and 22 weeks of age and euthanized at 28 days of gestation. A few days before mating and/or just before euthanasia, F1 female rabbits were fasted overnight, weighed, and blood sampled for steroids and biochemistry. Organs were weighed at euthanasia and the ovaries were collected. C/H and H/H F1 offspring had higher cholesterol and high-density lipoprotein plasma concentrations, together with a higher fat mass compared with C/C does, reflecting the effect of the postnatal diet; however, no effect of the antenatal diet was observed on most parameters. The number of primordial, primary and secondary follicles were not different between the groups, but a significantly higher number of atretic follicles was observed in the C/H (P<0.001) and in the H/C (P<0.001) compared with control C/C ovaries, demonstrating both an effect of prenatal and postnatal maternal nutrition. These data indicated that both maternal and postnatal high-fat diet may induce follicular apoptosis; however, in this model, the reproduction was not affected.

Is there a role for DHEA supplementation in women with diminished ovarian reserve?

PURPOSE

Poor ovarian reserve and poor ovarian response presents a challenge to IVF centers. Dehydroepiandrosterone (DHEA) supplementation is increasingly being used by many IVF centers around the world in poor responders despite the lack of convincing data. We therefore examined the rationale for the use of DHEA in poor responders, address the relevant studies, present new data, and address its potential mechanisms of action.

METHODS

All published articles on the role of DHEA in infertile women from 1990 to April 2013 were reviewed.

RESULTS

Several studies have suggested an improvement in pregnancy rates with the use of DHEA. Potential mechanisms include improved follicular steroidogenesis, increased IGF-1, acting as a pre-hormone for follicular testosterone, reducing aneuploidy, and increasing AMH and antral follicle count. While the role of DHEA is intriguing, evidence-based recommendations are lacking.

CONCLUSIONS

While nearly 25 % of IVF programs use DHEA currently, large randomized prospective trials are sorely needed. Until (and if) such trials are conducted, DHEA may be of benefit in suitable, well informed, and consented women with diminished ovarian reserve.

Metabolomic response of human embryonic stem cell-derived germ-like cells after exposure to steroid hormones

To assess the potential risks of human exposure to endocrine active compounds (EACs), the mechanisms of toxicity must first be identified and characterized. Currently, there are no robust in vitro models for identifying the mechanisms of toxicity in germ cells resulting from EAC exposure. Human embryonic stem cells can differentiate into numerous functional cell types including germ-like cells (GLCs). These cells possess characteristics indicative of a germ cell state, suggesting they offer a novel system to investigate the consequences of chemical exposure on normal germ cell processes. To characterize these processes, a metabolomic-based approach was employed to determine the response of GLCs following exposure to 0.001, 0.01, 0.1, 1, 10, or 100µM estradiol, testosterone, or progesterone for 48h. Following exposure, cellular extracts underwent gas chromatography coupled with mass spectrometry analysis. Models were then constructed using principal component analysis on acquired spectra to discriminate among steroid hormones as well as doses for each hormone. t-test comparisons generated a preliminary list of metabolites that were statistically significant in GLC's biochemical response to these steroid hormones. Steroid hormone exposures caused fluxes in intracellular pathways such as amino acid synthesis and metabolism, fatty acid synthesis, as well as cholesterol and lipoprotein metabolism. Further pathway analysis, based on these identified metabolites, will aid in modeling the response of GLCs to endogenous steroid hormones and allow for identification of biomarkers delineating germ cell-based developmental and reproductive pathways.

Dehydroepiandrosterone (DHEA) supplementation in diminished ovarian reserve (DOR)

BACKGROUND

With infertility populations in the developed world rapidly aging, treatment of diminished ovarian reserve (DOR) assumes increasing clinical importance. Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances with DOR, and is now utilized by approximately one third of all IVF centers world-wide. Increasing DHEA utilization and publication of a first prospectively randomized trial now warrants a systematic review.

METHODS

PubMed, Cochrane and Ovid Medline were searched between 1995 and 2010 under the following strategy: [<dehydroepiandrosterone or DHEA or androgens or testosterone > and <ovarian reserve or diminished ovarian reserve or ovarian function >]. Bibliographies of relevant publications were further explored for additional relevant citations. Since only one randomized study has been published, publications, independent of evidence levels and quality assessment, were reviewed.

RESULTS

Current best available evidence suggests that DHEA improves ovarian function, increases pregnancy chances and, by reducing aneuploidy, lowers miscarriage rates. DHEA over time also appears to objectively improve ovarian reserve. Recent animal data support androgens in promoting preantral follicle growth and reduction in follicle atresia.

DISCUSSION

Improvement of oocyte/embryo quality with DHEA supplementation potentially suggests a new concept of ovarian aging, where ovarian environments, but not oocytes themselves, age. DHEA may, thus, represent a first agent beneficially affecting aging ovarian environments. Others can be expected to follow.

A macrophage and theca cell-enriched stromal cell population influences growth and survival of immature murine follicles in vitro

Innovations in in vitro ovarian follicle culture have revolutionized the field of fertility preservation, but the successful culturing of isolated primary and small secondary follicles remains difficult. Herein, we describe a revised 3D culture system that uses a feeder layer of ovarian stromal cells to support early follicle development. This culture system allows significantly improved primary and early secondary follicle growth and survival. The stromal cells, consisting mostly of thecal cells and ovarian macrophages, recapitulate the in vivo conditions of these small follicles and increase the production of androgens and cytokines missing from stromal cell-free culture conditions. These results demonstrate that small follicles have a stage-specific reliance on the ovarian environment, and that growth and survival can be improved in vitro through a milieu created by pre-pubertal ovarian stromal cell co-culture.

Improvement in diminished ovarian reserve after dehydroepiandrosterone supplementation

Dehydroepiandrosterone (DHEA) has been reported to improve oocyte/embryo yields and oocyte/embryo quality in women with diminished ovarian reserve. Whether DHEA objectively improves ovarian reserve is, however, unknown. This study investigated 120 consecutive patients with diminished ovarian reserve, supplemented for 30-120 days (mean 73+/-27) with DHEA (25mg three times daily). Anti-Müllerian hormone (AMH) concentrations were determined in relationship to DHEA supplementation using linear regression and, longitudinally, by examining interaction between days of DHEA treatment and pregnancy success in respect to changes in AMH. AMH concentrations significantly improved after DHEA supplementation over time (P=0.002). Women under age 38 years demonstrated higher AMH concentrations and improved AMH concentrations more than older females. AMH improved longitudinally by approximately 60% (P<0.0002). Women reaching IVF experienced a 23.64% clinical pregnancy rate and conceiving women showed significantly improved AMH concentrations compared with those who did not (P=0.001). DHEA supplementation, thus, significantly improved ovarian reserve in parallel with longer DHEA use and was more pronounced in younger women.

Oocyte-granulosa-theca cell interactions during preantral follicular development

The preantral-early antral follicle transition is the penultimate stage of follicular development in terms of gonadotropin dependence and follicle destiny (growth versus atresia). Follicular growth during this period is tightly regulated by oocyte-granulosa-theca cell interactions. Formation of the theca cell layer is a key event that occurs during this transitional stage. Granulosal factor(s) stimulates the recruitment of theca cells from cortical stromal cells, while oocyte-derived growth differentiation factor-9 (GDF-9) is involved in the differentiation of theca cells during this early stage of follicular development. The preantral to early antral transition is most susceptible to follicular atresia. GDF-9 promotes follicular survival and growth during transition from preantral stage to early antral stage by suppressing granulosa cell apoptosis and follicular atresia. GDF-9 also enhances preantral follicle growth by up-regulating theca cell androgen production. Thecal factor(s) promotes granulosa cell proliferation and suppress granulosa cell apoptosis. Understanding the intraovarian mechanisms in the regulation of follicular growth and atresia during this stage may be of clinical significance in the selection of the best quality germ cells for assisted reproduction. In addition, since certain ovarian dysfunctions, such as polycystic ovarian syndrome and gonadotropin poor-responsiveness, are consequences of dysregulated follicle growth at this transitional stage, understanding the molecular and cellular mechanisms in the control of follicular development during the preantral-early antral transition may provide important insight into the pathophysiology and rational treatment of these conditions.

Growth differentiation factor 9 promotes rat preantral follicle growth by up-regulating follicular androgen biosynthesis

The transition from preantral to early antral stage is the penultimate stage of ovarian follicular development in terms of gonadotropin dependence and follicle destiny. Although oocyte-somatic cell communication is important in early follicular development, our knowledge of the precise role of the oocyte-derived growth differentiation factor (GDF)-9 during preantral follicle growth is incomplete. We examined whether and by what means oocyte-derived GDF-9 controls follicular development and steroidogenesis during the preantral to early antral transition, by a combination of in vitro gene manipulation (i.e. intraoocyte injection of GDF-9 antisense oligos) and preantral follicle culture. Intraoocyte injection of GDF-9 antisense suppressed rat preantral follicle growth in vitro, whereas GDF-9 enhanced follicular development. GDF-9 augmented testosterone production in preantral follicles. GDF-9 antisense suppressed androgen production and CYP17A1 mRNA expression in cultured follicles, a response attenuated by exogenous GDF-9. The nonaromatizable androgen 5alpha-dihydrotestosterone rescued the follicular growth arrest caused by GDF-9 down-regulation. The specific androgen receptor antagonist flutamide suppressed GDF-9-induced preantral follicle growth in vitro. The data suggest that GDF-9 plays an important role in promoting preantral follicle growth by up-regulating follicular androgen biosynthesis. GDF-9 is essential for CYP17A1 expression during follicular development from the preantral to the early antral stage.

Growth differentiation factor-9 and anti-Müllerian hormone expression in cultured human follicles from frozen-thawed ovarian tissue

In-vitro growth of frozen-thawed human follicles is perceived as a potential option for restoring women's fertility. The aims of this study were: (i) to test the usefulness of a defined serum-free medium for growth of frozen-thawed human follicles; and (ii) to evaluate the expression of growth differentiation factor-9 (GDF-9) and anti-Müllerian hormone (AMH) in cultured follicles. Frozen-thawed ovarian cortical pieces from 7-, 12-, 25- and 27-year-old women were cultured for 0, 7, 14, 21 and 28 days. Follicle developmental quality was evaluated and expression of proliferating cell nuclear antigen (PCNA) (day 21), GDF-9 (days 14 and 28) and AMH (day 21) was assessed by immunohistochemistry. Primary follicles and enclosed oocytes underwent significant growth at the end of culture (P < 0.05). Cultured follicles from all patients studied reached the early secondary stage and a few follicles from two patients developed up to the secondary stage. The rate of atresia was variable throughout the culture periods. PCNA was expressed in the granulosa cells at all the different follicular stages. AMH and GDF-9 immunostaining were found respectively in the granulosa cells and oocytes after several weeks of culture. The transition from resting to growing follicles leading to the development of secondary follicles showed the normal expression patterns of GDF-9 and AMH.