A putative role for anti-Müllerian hormone (AMH) in optimising ovarian reserve expenditure

A matter of new life and cell death: programmed cell death in the mammalian ovary

BACKGROUND

The mammalian ovary is a unique organ that displays a distinctive feature of cyclic changes throughout the entire reproductive period. The estrous/menstrual cycles are associated with drastic functional and morphological rearrangements of ovarian tissue, including follicular development and degeneration, and the formation and subsequent atrophy of the corpus luteum. The flawless execution of these reiterative processes is impossible without the involvement of programmed cell death (PCD).

MAIN TEXT

PCD is crucial for efficient and careful clearance of excessive, depleted, or obsolete ovarian structures for ovarian cycling. Moreover, PCD facilitates selection of high-quality oocytes and formation of the ovarian reserve during embryonic and juvenile development. Disruption of PCD regulation can heavily impact the ovarian functions and is associated with various pathologies, from a moderate decrease in fertility to severe hormonal disturbance, complete loss of reproductive function, and tumorigenesis. This comprehensive review aims to provide updated information on the role of PCD in various processes occurring in normal and pathologic ovaries. Three major events of PCD in the ovary-progenitor germ cell depletion, follicular atresia, and corpus luteum degradation-are described, alongside the detailed information on molecular regulation of these processes, highlighting the contribution of apoptosis, autophagy, necroptosis, and ferroptosis. Ultimately, the current knowledge of PCD aberrations associated with pathologies, such as polycystic ovarian syndrome, premature ovarian insufficiency, and tumors of ovarian origin, is outlined.

CONCLUSION

PCD is an essential element in ovarian development, functions and pathologies. A thorough understanding of molecular mechanisms regulating PCD events is required for future advances in the diagnosis and management of various disorders of the ovary and the female reproductive system in general.

Intergenerational effects on fertility in male and female mice after chronic exposure to environmental doses of NSAIDs and 17α-ethinylestradiol mixtures

Non-steroidal anti-inflammatory drugs (NSAIDs) and 17α-ethinylestradiol (EE2) are extensively used in human and veterinary medicine. Due to their partial removal by wastewater treatment plants, they are frequent environmental contaminants, particularly in drinking water. Here, we investigated the adverse outcomes of chronic exposure to mixtures of NSAIDs (ibuprofen, 2hydroxy-ibuprofen, diclofenac) and EE2 at two environmentally relevant doses in drinking water, on the reproductive organ development and fertility in F1-exposed male and female mice and in their F2 offspring. In male and female F1 mice, which were exposed to these mixtures, reproductive organ maturation, estrous cyclicity, and spermiogenesis were altered. These defects were observed also in F2 animals, in addition to some specific sperm parameter alterations in F2 males. Transcriptomic analysis revealed significant changes in gene expression patterns and associated pathways implicated in testis and ovarian physiology. Chronic exposure of mice to NSAID and EE2 mixtures at environmental doses intergenerationally affected male and female fertility (i.e. total number of pups and time between litters). Our study provides new insights into the adverse effects of these pharmaceuticals on the reproductive health and will facilitate the implementation of a future regulatory environmental risk assessment of NSAIDs and EE2 for human health.

Making a good egg: human oocyte health, aging, and in vitro development

Mammalian eggs (oocytes) are formed during fetal life and establish associations with somatic cells to form primordial follicles that create a store of germ cells (the primordial pool). The size of this pool is influenced by key events during the formation of germ cells and by factors that influence the subsequent activation of follicle growth. These regulatory pathways must ensure that the reserve of oocytes within primordial follicles in humans lasts for up to 50 years, yet only approximately 0.1% will ever be ovulated with the rest undergoing degeneration. This review outlines the mechanisms and regulatory pathways that govern the processes of oocyte and follicle formation and later growth, within the ovarian stroma, through to ovulation with particular reference to human oocytes/follicles. In addition, the effects of aging on female reproductive capacity through changes in oocyte number and quality are emphasized, with both the cellular mechanisms and clinical implications discussed. Finally, the details of current developments in culture systems that support all stages of follicle growth to generate mature oocytes in vitro and emerging prospects for making new oocytes from stem cells are outlined.

Does the addition of metformin to carboplatin treatment decreases ovarian reserve damage associated with carboplatin usage?

BACKGROUND

We aimed to determine whether adding metformin to carboplatin treatment would reduce the damage to ovarian reserve associated with carboplatin use.

METHODS

We included 35 adult female non-pregnant albino Wistar rats approximately three months old, weighing 220-310 g. The rats were divided into five groups of seven rats according to the treatment they received. Carboplatin and salin was given to Group 2, and carboplatin plus metformin was given to Group 3. Group 4 was administered only metformin. Group 5 was administered only salin. Carboplatin was given to Groups 2 and 3 as a single dose on the 15th day, while metformin was given to Groups 3 and 4 during the 28-day experiment. After oophorectomy, histopathologic analyses of primordial, primary, secondary, and tertiary Graff follicles according to the epithelial cells surrounding the oocyte and total follicular number were conducted per section. Serum Anti-Mullerian Hormone (AMH), tissue catalase, and malonyl dialdehyde levels were measured and compared within each group.

RESULTS

The baseline and 15th-day serum AMH values of the menstrual cycle were compared among the groups, and no statistically significant differences were observed (p > 0.05). Group 3, which was given both carboplatin and metformin, had statistically significantly higher 28th-day AMH levels than Group 2, which was given only carboplatin and saline (p < 0.001). The number of primordial follicles in Group 3 was found to be statistically significantly higher than in Group 2 (p < 0.001). Tissue catalase enzyme levels in Group 3 were statistically significantly higher than in Group 2 (p < 0.001). Tissue malondialdehyde levels in Group 2 were statistically significantly higher than tissue malondialdehyde levels in Groups 3 and 4 (p < 0.001).

CONCLUSIONS

Metformin may attenuate carboplatin-induced ovarian damage, possibly through its antioxidative effects.

Association of the Cumulative Live Birth Rate with the Factors in Assisted Reproductive Technology: A Retrospective Study of 16,583 Women

The cumulative live birth rate (CLBR) can better reflect the overall treatment effect by successive treatments, and continuous rather than categorical variables as exposure variables can increase the statistical power in detecting the potential correlation. Therefore, the dose-response relationships might find an optimal dose for the better CLBR, offering evidence-based references for clinicians. To determine the dose-response relationships of the factors and the optimal ranges of the factors in assisted reproductive technology (ART) associated with a higher CLBR, this study retrospectively analyzed 16,583 patients undergoing the first in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) from January 2017 to January 2019. Our study demonstrated the optimal ranges of age with a higher CLBR were under 32.10 years. We estimated the CLBR tends to increase with increased levels of AMH at AMH levels below 1.482 ng/mL, and the CLBR reaches a slightly high level at AMH levels in the range from 2.58-4.18 ng/mL. The optimal ranges of basal FSH with a higher CLBR were less than 9.13 IU. When the number of cryopreserved embryos was above 1.055 and the number of total transferred embryos was 2, the CLBR was significantly higher. In conclusion, there is a non-linear dose-response relationship between the CLBR with age, AMH, basal FSH, and the number of cryopreserved embryos and total transferred embryos. We proposed the optimal ranges of the five factors that were correlated with a higher CLBR in the first oocyte retrieval cycle, which may help consultation at IVF clinics.

The Cut-Off Value of Serum Anti-Müllerian Hormone Levels for the Diagnosis of Turner Syndrome with Spontaneous Puberty

OBJECTIVE

Preservation of fertility in Turner syndrome (TS) patients may be feasible through cryopreservation of ovarian tissue before follicles begin to disappear. Anti-Müllerian hormone (AMH) is said to be a predictive factor of spontaneous pubertal development in TS. We aimed to determine the cut-off values of AMH for the diagnosis of TS girls with spontaneous puberty. Design and methods: A total of 95 TS patients between 4 and 17 years were evaluated at the Department of Pediatric Genetic Metabolism and Endocrinology from July 2017 to March 2022. Serum AMH, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were analyzed according to age, karyotype, pubertal development, and ultrasound ovarian visualization. Receiver-operating characteristic (ROC) curve analyzes were used to test the utility of AMH for the diagnosis of TS girls with spontaneous puberty.

RESULTS

One-fourth of TS girls aged 8-17 years had spontaneous breast development, with the ratios as follows: 45, X (6/28, 21.4%), mosaicism (7/12, 58.3%), and mosaicism with structural X chromosome abnormalities (SCA) (2/13, 15.4%), SCA (1/13, 7.7%), and Y chromosome (1/3, 33.3%). The AMH cut-off value for the prediction of spontaneous puberty in TS patients was 0.07 ng/ml, with sensitivity and specificity both at 88%. FSH, LH levels, and Karyotypes could not be considered as markers of spontaneous puberty in TS (P > 0.05). A strong relationship was observed between serum AMH levels and spontaneous puberty or ultrasound bilateral ovarian visualization.

CONCLUSIONS

The AMH cut-off value for the prediction of spontaneous puberty in TS girls aged 8-17 years was 0.07 ng/ml, with sensitivity and specificity both at 88%. However, spontaneous puberty in these patients is not predictable based on karyotype or FSH or LH levels.

Repeated Superovulation Accelerates Primordial Follicle Activation and Atresia

For humans, ARTs (assisted reproductive technologies) have become the most effective method to treat subfertility/infertility in clinic. To obtain enough oocytes during ART, ovarian stimulation is performed by exogenous hormones, and some patients undergo several ovarian stimulation cycles. Although some adverse effects of ARTs on women and offspring are reported, few studies are focused on the effects of multiple superovulation on ovarian reserve. In the present study, we found that repeated superovulation significantly reduced primordial follicle number and the serum AMH. Compared to the decreased antral follicle number, the expression of genes related to primordial follicle activation, such as Foxo3, Akt, and Rptor, and the atretic follicle number in ovaries were increased by superovulation times. We further found that repeated superovulation reduced the plasma level of FSH, LH, and estradiol, and increased the expression of genes related to apoptosis (Bax, Casp3 (caspase-3), Casp8, and Casp9) in granulosa cells, providing evidence that repeated superovulation disrupted the balance between survival and death in granulosa cells. In summary, our results suggest that repeated superovulation has adverse effects on folliculogenesis.

Predictive value of anti-Mullerian hormone for pregnancy outcomes following assisted reproductive techniques (ART) in Southwest China

BACKGROUND

Anti-Müllerian hormone (AMH) is secreted by granulosa cells in preantral follicles and small antral follicles. There is limited information about whether serum AMH levels are related to pregnancy outcomes during in vitro fertilization and embryo transfer (IVF-ET). The aim of this study was to provide a theoretical basis for improving pregnancy outcomes.

METHODS

A retrospective cohort study was conducted on infertile women who were treated at the Reproductive Centre of the Affiliated Hospital of Southwest Medical University between September 2018 and September 2019. The sample included 518 participants from Southwest China. The participants were divided into 2 groups according to their AMH level. Their data were retrieved from the medical records: days and dosage of gonadotropin (Gn) (one bottle equals 75 IU), the number of oocytes obtained, the number of oocytes in metaphase II (MII) and the number of high-quality embryos. The pregnancy outcomes were followed up and divided into two groups according to whether they were pregnant or not, with statistical analysis of the parameters related to the in vitro fertilization process performed separately.

RESULTS

Compared to a lower AMH level (AMH ≤ 1.1), a higher AMH level (AMH > 1.1) resulted in less total Gn (bottle) (P = 0.00 < 0.05) and a lower starting Gn (IU) (P = 0.00 < 0.05), while the number of oocytes obtained,MII,cleavages and high-quality embryos were higher (P = 0.00 < 0.05). The participants' pregnancy outcomes (ectopic pregnancy, miscarriage, singleton, twin, multiple births) were found to not be predictable by AMH through ROC curves (P = 0.980, 0.093, 0.447, 0.146, 0.526, and 0.868 > 0.05). For participants in the pregnancy group, although AMH was lower in the nonpregnant participants(P = 0.868 > 0.05), the difference was not statistically significant, and the correlation coefficients between the two groups suggested no differences in the IVF process, except for the starting Gn (IU) (P = 0.038 < 0.05).

CONCLUSION

AMH has clinical application value in predicting ovarian reserve function, providing guidance and suggestions for the specific formulation of ovulation promotion programs with assisted reproductive technology, but it cannot effectively predict the outcome of clinical pregnancy.

Recapitulating human ovarian aging using random walks

Mechanism(s) that control whether individual human primordial ovarian follicles (PFs) remain dormant, or begin to grow, are all but unknown. One of our groups has recently shown that activation of the Integrated Stress Response (ISR) pathway can slow follicular granulosa cell proliferation by activating cell cycle checkpoints. Those data suggest that the ISR is active and fluctuates according to local conditions in dormant PFs. Because cell cycle entry of (pre)granulosa cells is required for PF growth activation (PFGA), we propose that rare ISR checkpoint resolution allows individual PFs to begin to grow. Fluctuating ISR activity within individual PFs can be described by a random process. In this article, we model ISR activity of individual PFs by one-dimensional random walks (RWs) and monitor the rate at which simulated checkpoint resolution and thus PFGA threshold crossing occurs. We show that the simultaneous recapitulation of (i) the loss of PFs over time within simulated subjects, and (ii) the timing of PF depletion in populations of simulated subjects equivalent to the distribution of the human age of natural menopause can be produced using this approach. In the RW model, the probability that individual PFs grow is influenced by regionally fluctuating conditions, that over time manifests in the known pattern of PFGA. Considered at the level of the ovary, randomness appears to be a key, purposeful feature of human ovarian aging.

High Housing Density-Induced Chronic Stress Diminishes Ovarian Reserve via Granulosa Cell Apoptosis by Angiotensin II Overexpression in Mice

Repeated and prolonged stress causes hypothalamic-pituitary-adrenal (HPA) dysregulation. Excessive hypothalamic-pituitary-adrenal axis activity has been linked to inadequate activation of the hypothalamus-pituitary-ovarian axis, which controls the growth and development of ovarian follicles and oocytes. Therefore, we assessed the ovarian reserve under high-housing-density-induced prolonged stress, and investigated the mechanisms underlying diminished ovarian reserve in this study. Eight-week-old female C57BL/6 mice were housed for 10 weeks under different housing densities. We then assessed hormone levels, performed histology and immunohistochemistry analyses of ovarian follicles, evaluated ovarian mRNA expression, and measured angiotensin II-mediated apoptosis in vitro. More densely housed mice presented increased corticosterone levels and decreased follicle-stimulating and luteinizing hormone levels. Moreover, mice exposed to prolonged ordinary stress showed a reduced level of serum anti-Müllerian hormone and an increased number of atretic ovarian follicles. Stressed mice showed increased levels of angiotensinogen and angiotensin II in the ovaries and serum. Furthermore, our in vitro study confirmed that high-housing-density-related stress induced granulosa cell apoptosis, resulting in diminished ovarian reserves. Collectively, our findings highlight the importance of women managing everyday stress to maintain their reproductive health.

Cortisol safeguards oogenesis by promoting follicular cell survival

The role of glucocorticoids in oogenesis remains to be elucidated. cyp11c1 encodes the key enzyme involved in the synthesis of cortisol, the major glucocorticoid in teleosts. In our previous study, we mutated cyp11c1 in tilapia and analyzed its role in spermatogenesis. In this study, we analyzed its role in oogenesis. cyp11c1^+/- XX tilapia showed normal ovarian morphology but poor egg quality, as indicated by the mortality of embryos before 3 d post fertilization, which could be partially rescued by the supplement of exogenous cortisol to the mother fish. Transcriptome analyses revealed reduced expression of maternal genes in the eggs of the cyp11c1^+/- XX fish. The cyp11c1^-/- females showed impaired vitellogenesis and arrested oogenesis due to significantly decreased serum cortisol. Further analyses revealed decreased serum E2 level and expression of amh, an important regulator of follicular cell development, and increased follicular cell apoptosis in the ovaries of cyp11c1^-/- XX fish, which could be rescued by supplement of either exogenous cortisol or E2. Luciferase assays revealed a direct regulation of cortisol and E2 on amh transcription via GRs or ESRs. Taken together, our results demonstrate that cortisol safeguards oogenesis by promoting follicular cell survival probably via Amh signaling.

Bisphenol S Impairs Oestradiol Secretion during In Vitro Basal Folliculogenesis in a Mono-Ovulatory Species Model

Bisphenol S (BPS) affects terminal folliculogenesis by impairing steroidogenesis in granulosa cells from different species. Nevertheless, limited data are available on its effects during basal folliculogenesis. In this study, we evaluate in vitro the effects of a long-term BPS exposure on a model of basal follicular development in a mono-ovulatory species. We cultured ovine preantral follicles (180−240 μm, n = 168) with BPS (0.1 μM (possible human exposure dose) or 10 μM (high dose)) and monitored antrum appearance and follicular survival and growth for 15 days. We measured hormonal secretions (oestradiol (at day 13 [D13]), progesterone and anti-Müllerian hormone [D15]) and expression of key follicular development and redox status genes (D15) in medium and whole follicles, respectively. BPS (0.1 µM) decreased oestradiol secretion compared with the control (−48.8%, p < 0.001), without significantly impairing antrum appearance, follicular survival and growth, anti-Müllerian hormone and progesterone secretion and target gene expression. Thus, BPS could also impair oestradiol secretion during basal folliculogenesis as it is the case during terminal folliculogenesis. It questions the use of BPS as a safe BPA substitute in the human environment. More studies are required to elucidate mechanisms of action of BPS and its effects throughout basal follicular development.

Targeting signaling pathways involved in primordial follicle growth or dormancy: potential application in prevention of follicular loss and infertility

INTRODUCTION

Premature ovarian failure (POF) is one of the important causes of infertility in females. To date, no efficient preventive pharmacological treatment has been offered to prevent POF. Therefore, it is necessary to focus on strategies that provide a normal reproductive lifespan to females at risk of developing POF.

AREAS COVERED

Recently, attention has been drawn to discovering pathways involved in primordial follicle activation, as the inhibition of this process might maintain the stock of primordial follicles and therefore, prevent POF. In vitro and animal studies have resulted in the discovery of several of these pathways that can be used to develop new treatments for POF. These studies show crosstalk of these pathways at different levels. One of the important crossing points of many of these pathways involves anti-Mullerian hormone (AMH). Herein, we discuss different aspects of this topic by reviewing related published articles indexed in PubMed and Web of Science as of December 2021.

EXPERT OPINION

Although the findings seem promising, most of the studies were conducted on animals, and the interaction between these factors and the possible outcomes of their administration in the long term are still unknown. Therefore, further investigation is necessary to assess these aspects.

The role of Hippo pathway signaling and A-kinase anchoring protein 13 in primordial follicle activation and inhibition

OBJECTIVE

To determine whether the mechanotransduction and pharmacomanipulation of A-kinase anchoring protein 13 (AKAP13) altered Hippo signaling pathway transcription and growth factors in granulosa cells. Primary ovarian insufficiency is the depletion or dysfunction of primordial ovarian follicles. In vitro activation of ovarian tissue in patients with primary ovarian insufficiency alters the Hippo and phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B/forkhead box O3 pathways. A-kinase anchoring protein 13 is found in granulosa cells and may regulate the Hippo pathway via F-actin polymerization resulting in altered nuclear yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif coactivators and Tea domain family (TEAD) transcription factors.

DESIGN

Laboratory studies.

SETTING

Translational science laboratory.

PATIENT(S)

None.

INTERVENTION(S)

COV434 cells, derived from a primary human granulosa tumor cell line, were studied under different cell density and well stiffness conditions. Cells were transfected with a TEAD-luciferase (TEAD-luc) reporter as well as expression constructs for AKAP13 or AKAP13 mutants and then treated with AKAP13 activators, inhibitors, and follicle-stimulating hormone.

MAIN OUTCOME MEASURE(S)

TEAD gene activation or inhibition was measured by TEAD-luciferase assays. The messenger ribonucleic acid levels of Hippo pathway signaling molecules, including connective tissue growth factor (CTGF), baculoviral inhibitors of apoptosis repeat-containing 5, Ankyrin repeat domain-containing protein 1, YAP1, and TEAD1, were measured by quantitative real-time polymerase chain reaction. Protein expressions for AKAP13, CTGF, YAP1, and TEAD1 were measured using Western blot.

RESULT(S)

Increased TEAD-luciferase activity and expression of markers for cellular growth were associated with decreased cell density, increased well stiffness, and AKAP13 activator (A02) treatment. Additionally, decreased TEAD-luc activity and expression of markers for cellular growth were associated with AKAP13 inhibitor (A13) treatment, including a reduced expression of the BIRC5 and ANKRD1 (YAP-responsive genes) transcript levels and CTGF protein levels. There were no changes in TEAD-luc with follicle-stimulating hormone treatment, supporting Hippo pathway involvement in the gonadotropin-independent portion of folliculogenesis.

CONCLUSION(S)

These findings suggest that AKAP13 mediates Hippo-regulated changes in granulosa cell growth via mechanotransduction and pharmacomanipulation. The AKAP13 regulation of the Hippo pathway may represent a potential target for regulation of follicle activation.

The Predictive Levels of Serum Anti-Müllerian Hormone and the Combined Index of the Number of Retrieved Oocytes and Good-Quality Embryos in Advanced-Age Infertile Women

The primary objective of the study was to assess the values of serum anti-Müllerian hormone (AMH) levels and the combined index for the prediction of number of oocytes retrieved (NOR) and number of good-quality embryos (GQE) in infertile women undergoing IVF/ICSI treatment. A group of 521 infertile women aged 21-46 years were recruited as subject in this study. Serum AMH, hormones, and antral follicle count (AFC) were measured. The infertile women were categorized into three groups: 21-34 years (reproductive age), 35-39 years (reproductive age), and 40-46 years (advanced-age infertile). The predictive accuracy of variables was analyzed by the receiver operating characteristic (ROC) curve. AFC, AFC/age ratio, AMH/age ratio, and ovarian response prediction index (ORPI) decreased gradually, while AMH decreased significantly with increase in age. Moreover, NOR and GQE were positively correlated with AFC, AMH, AFC/age ratio, AMH/age ratio, and ORPI (P < 0.001). A statistical significance was observed in predicted oocyte retrieval including AMH, AMH/age ratio, and ORPI between 21-34 years and 35-46 years; especially in the 35-46 years group, these variables reached a "high" grade in the diagnostic accuracy because area under curve (AUC) ranged from 0.982 to 0.988 significantly. No statistical significance was observed for FSH, AMH, AFC, and related combined index predicting GQE. The predictive value of AFC and AFC/age ratio was limited regarding oocyte retrieval; however, AMH, AMH/age ratio, and ORPI concurrently had an excellent value for predicting NOR in reproductive-age women, especially in advanced-age infertile women.

Endometrioma surgery-a systematic review and meta-analysis of the effect on antral follicle count and anti-Müllerian hormone

OBJECTIVE

Accurate preoperative counseling about whether an endometriotic cystectomy has a detrimental effect on the ovarian reserve has been a considerable challenge, because studies assessing the postoperative antral follicle counts and anti-Müllerian hormone levels have reported conflicting results. Our objective was to explore the impact of endometriotic cystectomy on both the anti-Müllerian hormone levels and antral follicle counts, with focus on prospective studies in which both variables were measured for each woman concurrently (overcoming unmeasured confounding), in the same setting (overcoming surgical technique differences), and at the same 3 postoperative time points, namely early (1-6 weeks), intermediate (2-6 months) and late (9-18 months), to overcome time-sensitive changes.

DATA SOURCES

Databases of PubMed, ClinicalTrials.gov, the Cochrane Library, Web of Science, and EBSCO were searched between January 2000 and October 2020.

STUDY ELIGIBILITY CRITERIA

Only prospective cohort studies that evaluated the impact of endometriotic stripping cystectomy on anti-Müllerian hormone levels and antral follicle counts in the same women, at matching time points, and in the same setting were eligible.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two authors performed the screening and data extraction independently.

RESULTS

A total of 14 prospectively designed studies were eligible for the meta-analysis and included 650 women. The included studies had a low risk of bias. The postoperative weighted mean differences in serum anti-Müllerian hormone levels dropped significantly when compared with the preoperative levels by an estimated 1.77 ng/mL (95% confidence interval, 0.77-2.77; P<.001), 1.17 ng/mL (95% confidence interval, 0.66-1.67; P<.001), and 2.13 ng/mL (95% confidence interval, 1.61-2.65; P<.001) at the early (1-6 weeks), intermediate (2-6 months), and late (9-18 months) time points, respectively. This corresponded to a mean reduction in serum anti-Müllerian hormone levels at each of the 3-time points of 44.4%, 35.1%, and 54.2%, respectively. Conversely, the postoperative weighted mean difference in the antral follicle count estimates did not change significantly at any of the 3 time points; the early antral follicle count was 0.70 (95% confidence interval, -2.71 to 3.56; P=.63), the intermediate count was -0.94 (95% confidence interval, -2.53 to 0.65; P=.25), and the late count was 2.58 (95% confidence interval, -0.43 to 5.58; P=.09). Overall, high levels of heterogeneity were encountered (I² ranging between 92% and 94% for the anti-Müllerian hormone levels and between 94% and 98% for the antral follicle counts at the 3 time points), which were attenuated when similar anti-Müllerian hormone assays were compared, and the meta-regression suggested that age did not contribute to heterogeneity.

CONCLUSION

Endometriotic cystectomies are associated with a significant reduction in the serum anti-Müllerian hormone levels but not in the antral follicle counts, with the detrimental effects on the anti-Müllerian hormone levels consistently detectable at the early-, intermediate-, and late-postoperative time points. In women with endometrioma, the anti-Müllerian hormone level may provide a more accurate assessment of the risk for iatrogenic depletion of the ovarian reserve.

FMR1 and AKT/mTOR Signaling in Human Granulosa Cells: Functional Interaction and Impact on Ovarian Response

We aimed to determine whether a functional link with impact on female ovarian reserve exists between FMR1 expression and expression ratios of AKT/mTOR signaling genes in human granulosa cells in vivo, as suggested from prior in vitro data. Three hundred and nine women, who were classified as normal (NOR; n = 225) and poor (POR; n = 84) responders based on their ovarian reserve, were recruited during stimulation for assisted reproductive techniques. Expressions of FMR1 and of key genes of the AKT/mTOR and AKT/FOXO1/3 signaling pathways were comparatively analyzed in their granulosa cells. FMR1 expression in granulosa cells of NOR and POR correlated significantly with AKT1, TSC2, mTOR, and S6K expression. No correlation was found between FMR1 and FOXO1 in all, and FOXO3 expression in POR, patients. AKT1 expression was significantly higher and FOXO1 expression lower in POR samples, whereas AKT1 expression was lower and FOXO1 expression was higher in NOR samples. In human native granulosa cells, FMR1 expression significantly correlated with the expression of key genes of the AKT/mTOR signaling pathway, but not with the FOXO1/3 signaling pathway. Our data point to a functional link between FMR1 expression and expression of the AKT/mTOR signaling pathway genes controlling human follicular maturation.

Anti-Müllerian Hormone Accelerates Pathological Process of Insulin Resistance in Polycystic Ovary Syndrome Patients

Insulin resistance (IR) is one of the most common features of polycystic ovary syndrome (PCOS), which is related to obesity. Whether increased anti-Müllerian hormone (AMH) levels in PCOS are involved in the pathogenesis of insulin resistance remains unclear. We investigated serum levels of leptin and AMH along with basic clinical and metabolic parameters in 114 PCOS patients and 181 non-PCOS women. PCOS patients presented higher fasting blood glucose, insulin concentrations and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) in addition to body mass index (BMI), lipids profiles and hormone levels. HOMA-IR showed a positive correlation with BMI, AMH, leptin, and low-density lipoprotein-cholesterol (LDL-c) levels. Interestingly, AMH is strongly positively correlated with HOMA-IR and insulin concentrations for 1st and 2nd hours of glucose treatment after fasting. Among PCOS women with BMI≥25 kg/m², high AMH level group showed an increased HOMA-IR when compared to normal AMH level. However, among PCOS women with normal BMI, women with high AMH presented an elevated fasting insulin levels but not HOMA-IR when compared to normal AMH group. In vitro treatment of isolated islet cells with high concentration of leptin (200 ng/ml) or high leptin plus high concentration of AMH (1 ng/ml) significantly enhanced insulin secretion. Importantly, co-treatment of AMH plus leptin upregulates the expression of pro-apoptotic proteins, such as Bax, caspase-3, and caspase-8 after incubating with a high level of glucose. These results suggest that AMH may involve in the pathological process of pancreatic β-cells in obese PCOS women.

A Prepubertal Mice Model to Study the Growth Pattern of Early Ovarian Follicles

Early folliculogenesis begins with the activation of the follicle and ends with the formation of the follicular antrum, which takes up most of the time of folliculogenesis. In this long process, follicles complete a series of developmental events, including but not limited to granulosa cell (GC) proliferation, theca folliculi formation, and antrum formation. However, the logical or temporal sequence of these events is not entirely clear. This study demonstrated in a mouse model that completion of early folliculogenesis required a minimum of two weeks. The oocyte reached its largest size in the Type 4-5 stage, which was therefore considered as the optimum period for studying oogenesis. Postnatal days (PD) 10-12 were regarded as the crucial stage of theca folliculi formation, as Lhcgr sharply increased during this stage. PD13-15 was the rapid growth period of early follicles, which was characterized by rapid cell proliferation, the sudden emergence of the antrum, and increased Fshr expression. The ovarian morphology remained stable during PD15-21, but antrum follicles accumulated gradually. Atresia occurred at all stages, with the lowest rate in Type 3 follicles and no differences among early Type 4-6 follicles. The earliest vaginal opening was observed at PD24, almost immediately after the first growing follicular wave. Therefore, the period of PD22-23 could be considered as a suitable period for studying puberty initiation. This study objectively revealed the pattern of early folliculogenesis and provided time windows for the study of biological events in this process.

High anti-Müllerian hormone levels might not reflect the likelihood of clinical pregnancy rate in IVF/ICSI treatment

Objective:

To investigate if high anti-Müllerian hormone (AMH) concentration is a useful tool to predict the outcome of assisted reproductive treatment.

Methods:

Retrospective cohort study involving 520 patients who underwent IVF/ICSI procedures in a university hospital. We measured the serum AMH level on day 3 of the menstrual cycle. Based on AMH levels, we divided the patients into three groups as follows: low (<25th percentile) AMH group, average (25th to 75th percentile) AMH group and high (>75th percentile) AMH group. We recorded the fertilization rate (FR), the number of oocytes retrieved, the number of good quality embryos (GQEs) and the clinical pregnancy rate (CPR).

Results:

There was no difference between the three AMH groups in terms of maternal age, body mass index (BMI), follicle-stimulating hormone (FSH), estradiol (E2), luteinizing hormone (LH) and testosterone (T) in the IVF/ICSI cycles. The women in the high serum AMH group had a higher number of retrieved oocytes than those in the low or average AMH groups (p < 0.01) in the IVF/ICSI cycles. Compared with the low or average AMH groups, the women with high AMH levels had a higher number of good quality embryos (GQEs) in the IVF/ICSI cycles (p < 0.01). However, high AMH women had no significantly higher clinical pregnancy rate (CPR) compared to the women in the low or average AMH groups. In addition, for the prediction of CPR, the AMH levels alone were not an independent predictor of CPR for IVF and ICSI cycles in the ROC curve analysis.

Conclusions:

High anti-Müllerian hormone levels are an independent predictor of the number of retrieved oocytes and good quality embryos (GQEs), but might not reflect the likelihood of higher clinical pregnancy rates (CPR) in IVF/ICSI treatment.

Current mechanisms of primordial follicle activation and new strategies for fertility preservation

Premature ovarian insufficiency (POI) is characterized by symptoms caused by ovarian dysfunction in patients aged <40 years. It is associated with a shortened reproductive lifespan. The only effective treatment for patients who are eager to become pregnant is IVF/Embryo Transfer (ET) using oocytes donated by young women. However, the use of the technique is constrained by the limited supply of oocytes and ethical issues. Some patients with POI still have some residual follicles in the ovarian cortex, which are not regulated by gonadotropin. These follicles are dormant. Therefore, activating dormant primordial follicles (PFs) to obtain high-quality oocytes for assisted reproductive technology may bring new hope for patients with POI. Therefore, this study aimed to explore the factors related to PF activation, such as the intercellular signaling network, the internal microenvironment of the ovary and the environment of the organism. In addition, we discussed new strategies for fertility preservation, such as in vitro activation and stem cell transplantation.

Does open ovarian biopsy in prepubertal age affect ovarian reserve in a rat model?

BACKGROUND

Partial resection of the ovary carries a possible risk of fertility reduction. We studied the influence of open ovarian biopsy on ovarian reserve, including anti-Müllerian hormone and follicle-stimulating hormone serum level evaluation, in a prepubertal rat model.

METHODS

Interventions - the initial surgery was unilateral ovarian biopsy (38 rats, group B1, B2) or unilateral ovarian biopsy and ovarian resection of the contralateral gonad (38 rats, group BR1, BR2). The second operation was bilateral ovarian resection and total resection of the remaining ovary. All rats had hormone serum levels evaluated. The control group had only a blood test taken and bilateral ovarian resection done at the second intervention (30 rats, group C1, C2). The collected tissue was examined estimating follicle count and anti-Müllerian hormone immunoexpression.

RESULTS

Anti-Müllerian hormone levels were significantly lower at the second intervention in the group BR2 but significantly higher in the group C2. Follicle-stimulating hormone levels were significantly higher in all but one group (BR2).

CONCLUSIONS

Biopsy itself might not reduce ovarian reserve if done properly but we should know its possible negative effects in the case of a single remaining ovary.

Does large endometrioma per se increase AMH level?

Women with endometriosis, especially those with endometrioma, present a considerable challenge for ovarian reserve appraisal. This diagnostic difficulty arises from several fundamental questions inherently linked to patient management: the potential influence of endometrioma on ovarian reserve; the adverse effect of ovarian surgery on ovarian reserve; and the adequacy of the established ovarian reserve biomarkers, anti-Müllerian hormone and antral follicle count, to appraise ovarian reserve accurately in these women. Until recently, a key argument was that the development and growth of endometriomas is associated with a progressive damage to normal ovarian tissue, resulting in a concomitant reduction in serum AMH levels. Contrary to this widely accepted position; recent studies have reported that, in women with no previous history of ovarian surgery, AMH levels were increased in women with large endometriomas. These findings are surprising and, if replicated, would have substantial clinical implications. In this commentary, we would, however, urge caution before these reports lead to systematic changes in clinical practice, and recommend urgent replication as the finding linking large endometrioma to high serum AMH levels seems to be biologically implausible, and contradicts the existing extensive body of research.

Phytoestrogen genistein hinders ovarian oxidative damage and apoptotic cell death-induced by ionizing radiation: co-operative role of ER-β, TGF-β, and FOXL-2

Radiotherapy is a well-known cause of premature ovarian failure (POF). Therefore, we investigated the molecular influence of genistein (GEN) on the ovarian reserve of rats exposed to ϒ-radiation. Female Sprague Dawley rats were exposed to a 3.2 Gy γ-radiation to induce POF and/or treated with either GEN (5 mg/kg, i.p.) or Ethinyl estradiol (E2; 0.1 mg/kg, s.c.), once daily for 10 days. GEN was able to conserve primordial follicles stock and population of growing follicles accompanied with reduction in atretic follicles. GEN restored the circulating estradiol and anti-Müllerian hormone levels which were diminished after irradiation. GEN has potent antioxidant activity against radiation-mediated oxidative stress through upregulating endogenous glutathione levels and glutathione peroxidase activity. Mechanistically, GEN inhibited the intrinsic pathway of apoptosis by repressing Bax expression and augmenting Bcl-2 expression resulted in reduced Bax/Bcl-2 ratio with subsequent reduction in cytochrome c and caspase 3 expression. These promising effects of GEN are associated with improving granulosa cells proliferation. On the molecular basis, GEN reversed ovarian apoptosis through up-regulation of ER-β and FOXL-2 with downregulation of TGF-β expression, therefore inhibiting transition of primordial follicles to more growing follicles. GEN may constitute a novel therapeutic modality for safeguarding ovarian function of females' cancer survivors.

Control of Murine Primordial Follicle Growth Activation by IκB/NFκB Signaling

The transcription factor NFκB has been associated with the timing of menopause in a large human genome-wide association study. Furthermore, preclinical studies demonstrate that loss of Tumor necrosis factor alpha (Tnfα) or its receptor Tnfr2 slows primordial follicle growth activation (PFGA). Although Tnfα:receptor signaling stimulates NFκB and may mechanistically link these findings, very little is known about NFκB signaling in PFGA. Because signaling downstream of Tnfα/Tnfr2 ligand/receptor interaction has not been interrogated as relates to PFGA, we evaluated the expression of key NFκB signaling proteins in primordial and growing follicles, as well as during ovarian aging. We show that key members of the NFκB pathway, including subunits, activating kinases, and inhibitory proteins, are expressed in the murine ovary. Furthermore, the subunits p65 and p50, and the cytosolic inhibitory proteins IκBα and IκBβ, are present in ovarian follicles, including at the primordial stage. Finally, we assessed PFGA in genetically modified mice (AKBI) previously demonstrated to be resistant to inflammatory stress-induced NFκB activation due to overexpression of the NFκB inhibitory protein IκBβ. Consistent with the hypothesis that NFκB plays a key role in PFGA, AKBI mice exhibit slower PGFA than wild-type (WT) controls, and their ovaries contain nearly twice the number of primordial follicles as WT both at early and late reproductive ages. These data provide mechanistic insight on the control of PFGA and suggest that targeting NFκB at the level of IκB proteins may be a tractable route to slowing the rate of PFGA in women faced with early ovarian demise.

An explanation of the mechanisms underlying fragile X-associated premature ovarian insufficiency

Fragile X and fragile X-associated tremor-ataxia syndrome (FXTAS) are caused by mutations of the FMR1 gene. The mutations causing FXTAS can expand in a generation to a "full mutation" causing fragile X syndrome. The mutations causing FXTAS and the phenotype, fragile X-associated premature ovarian insufficiency (FXPOI), are referred to as the FMR1 premutation (PM). The objective of this paper was to formulate a theory to explain the Mechanism for FXPOI.Recent research on fragile X syndrome and FXTAS has led to sophisticated theories about the mechanisms underlying these diseases. It has been proposed that similar mechanisms underlie FXPOI. Utilizing recent research on FXTAS, but a more detailed application of ovarian physiology, we present a more ovarian specific theory as to the primary mechanism explaining the development of FXPOI.The FXPOI phenotype may best be viewed as derivative of the observation that fragile X PM carriers experience menopause an average of 5 years earlier than non-carriers. Women carrying the PM experience an earlier menopause because of an accelerated activation of their primordial follicle pool. This acceleration of primordial follicle activation occurs, in part, because of diminished AMH production. AMH production is diminished because of accelerated atresia of early antral follicles. This accelerated atresia likely occurs because the fragile X PM leads to a slowing of the rate of granulosa cell mitosis in some follicles.

Mapping molecular pathways for embryonic Sertoli cells derivation based on differentiation model of mouse embryonic stem cells

Background

Embryonic Sertoli cells (eSCs) have been known for playing important roles in male reproductive development system. In current studies, eSCs were mainly generated from induced intermediate mesoderm. The deriving mechanism of eSCs has been unclear so far. Therefore, this work was aimed to reveal the molecular pathways during derivation of eSCs.

Methods

In this scenario, a differentiation model from mouse embryonic stem cells (mESCs) to eSCs was established through spatiotemporal control of 5 key factors, Wilms tumor 1 homolog (Wt1), GATA binding protein 4 (Gata4), nuclear receptor subfamily 5, group A, member 1 (Nr5a1, i.e., Sf1), SRY (sex determining region Y)-box 9 (Sox9), doublesex, and mab-3 related transcription factor 1 (Dmrt1). To investigate the molecular mechanism, these key factors were respectively manipulated through a light-switchable (light-on) system, tetracycline-switchable (Tet-on) system, and CRISPR/Cas9 knock out (KO) system.

Results

Via the established approach, some embryonic Sertoli-like cells (eSLCs) were induced from mESCs and formed ring-like or tubular-like structures. The key factors were respectively manipulated and revealed their roles in the derivation of these eSLCs. Based on these results, some molecular pathways were mapped during the development of coelomic epithelial somatic cells to eSCs.

Conclusions

This differentiation model provided a high controllability of some key factors and brought a novel insight into the deriving mechanism of Sertoli cells.

Supplementary information

accompanies this paper at 10.1186/s13287-020-01600-2.

Early evaluation of survival of the transplanted ovaries through ultrasound molecular imaging via targeted nanobubbles

Schematic of AMH-targeted nanobubbles (NB_AMH) and their targeting ability to rat ovarian granulosa cells expressing AMH.

Amh regulate female folliculogenesis and fertility in a dose-dependent manner through Amhr2 in Nile tilapia

In the present study, Amh was found to be abundantly expressed in the granulosa cells of the primary growth follicles, and Amhr2 in the granulosa cells, oogonia and phase I oocytes in tilapia by immunohistochemistry. In addition, Amh and Amhr2 were also found to be expressed in the brain and pituitary. Heterozygous mutation of either amh or amhr2 resulted in increased primary growth follicles and decreased fertility, and homozygous mutation resulted in hypertrophic ovaries with significantly increased primary follicles and failed transition from primary to vitellogenic follicles. Expression of gnrh3 in the brain, fsh and lh in the pituitary and serum E2 concentration were significantly decreased in both mutants. Significantly increased apoptosis of follicle cells was observed in both mutants. However, administration of E2 failed to rescue the folliculogenesis defects of the mutants. Our results suggested that Amh acts in a dose-dependent manner by binding Amhr2 in tilapia.

Accelerated ovarian reserve depletion in female anti-Müllerian hormone knockout mice has no effect on lifetime fertility†

Anti-Müllerian hormone (AMH) inhibits the activation of primordial follicles in the ovary. This causes an increased rate of ovarian reserve depletion in Amh−/− mice. The depletion of the ovarian reserve is responsible for the onset of menopause but age-related infertility occurs in advance of ovarian reserve depletion. To determine whether accelerated loss of primordial follicles leads to earlier onset infertility, Amh−/− and Amh+/+ females were paired with Amh+/+ stud males and birth rates were recorded across the females’ reproductive lifespan. The number of primordial follicles remaining in the ovaries of Amh−/− and Amh+/+ females were quantified in two cohorts at 11–12 and 12–13 months of age. As expected, the ovarian reserve in the Amh−/− females became depleted approximately 1 month earlier than Amh+/+ females. However, no difference was observed in the cumulative number of births over the lifespan, nor were there any differences in mean littersize at any age. It is possible that the reproductive lifespan of mice is too short for sufficient divergence of primordial follicles numbers to cause differences in Amh−/− and Amh+/+ female fertility. An alternative explanation contradicts current thinking; the function of AMH may be unrelated to the longevity of the reproductive lifespan in female mice.

In utero exposure to acetaminophen and ibuprofen leads to intergenerational accelerated reproductive aging in female mice

Nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesic drugs, such as acetaminophen (APAP), are frequently taken during pregnancy, even in combination. However, they can favour genital malformations in newborn boys and reproductive disorders in adults. Conversely, the consequences on postnatal ovarian development and female reproductive health after in utero exposure are unknown. Here, we found that in mice, in utero exposure to therapeutic doses of the APAP-ibuprofen combination during sex determination led to delayed meiosis entry and progression in female F1 embryonic germ cells. Consequently, follicular activation was reduced in postnatal ovaries through the AKT/FOXO3 pathway, leading in F2 animals to subfertility, accelerated ovarian aging with abnormal corpus luteum persistence, due to decreased apoptosis and increased AKT-mediated luteal cell survival. Our study suggests that administration of these drugs during the critical period of sex determination could lead in humans to adverse effects that might be passed to the offspring.

Neoadjuvant Treatment With Müllerian-Inhibiting Substance Synchronizes Follicles and Enhances Superovulation Yield

Müllerian-inhibiting substance (MIS), also known as anti-Müllerian hormone, is thought to be a negative regulator of primordial follicle activation. We have previously reported that treatment with exogenous MIS can induce complete ovarian suppression within 5 weeks of treatment in mice. To investigate the kinetics of the return of folliculogenesis following the reversal of suppression, we treated animals with recombinant human MIS (rhMIS) protein for 40 days in adult female Nu/Nu mice and monitored the recovery of each follicle type over time. Following cessation of MIS therapy, secondary, and antral follicles returned within 30 days, along with the normalization of reproductive hormones, including LH, FSH, MIS, and Inhibin B. Furthermore, 30 days following MIS pretreatment, the number of antral follicles were significantly higher than controls, and superovulation with timed pregnant mare serum gonadotropin and human chorionic gonadotropin stimulation at this time point resulted in an approximately threefold increased yield of eggs. Use of the combined rhMIS-gonadotropin superovulation regimen in a diminished ovarian reserve (DOR) mouse model, created by 4-vinylcyclohexene dioxide treatment, also resulted in a twofold improvement in the yield of eggs. In conclusion, treatment with rhMIS can induce a reversible ovarian suppression, following which a rapid and synchronized large initial wave of growing follicles can be harnessed to enhance the response to superovulation. Therapies modulating MIS signaling may therefore augment the response to current ovarian stimulation protocols and could be particularly useful to women with DOR or poor responders to controlled ovarian hyperstimulation during in vitro fertilization.

Effect of laparoscopic endometrioma cystectomy on anti-Müllerian hormone (AMH) levels

OBJECTIVE

To investigate temporary or long-term changes of AMH after laparoscopic endometrioma cystectomy and its dependency on characteristics of endometriomas.

METHODS

One hundred and seventy-one women, open-labeled prospective study; five groups divided according age ≤/> 35, uni-/bilateral, cyst ≤/> 7 cm, coagulation/suture surgery, stage III/IV; between- and within-group analyses after 1, 3, 6, and 12 months.

RESULTS

After 12 months, compared to pretreament, AMH decreased significantly for patients with bilateral cysts, cyst size >7 cm and endometriosis stage IV. In the between-group analysis all comparisons were significant, with exception of the surgery type. However, this was different performing the multiple linear regression analysis suggesting lower postoperative decrease using suturing technique. This analysis also showed higher age at pretreatment and bilateral cysts as risk factor for AMH decline.

CONCLUSIONS

Effects of endometrioma cystectomy on AMH are dependent on characteristics of the endometrioma, showing long-term a decrease in patients with larger, bilateral cysts and in stage IV endometriosis, but only short-time decrease in smaller, unilateral cysts and stage III which sometimes also can fully recover in AMH production within one year. In our study suture compared to coagulation surgery was protective, i.e. may lead to lower postoperative AMH decline.

In Vivo Ablation of the Conserved GATA-Binding Motif in the Amh Promoter Impairs Amh Expression in the Male Mouse

GATA4 is an essential transcriptional regulator required for gonadal development, differentiation, and function. In the developing testis, proposed GATA4-regulated genes include steroidogenic factor 1 (Nr5a1), SRY-related HMG box 9 (Sox9), and anti-Müllerian hormone (Amh). Although some of these genes have been validated as genuine GATA4 targets, it remains unclear whether GATA4 is a direct regulator of endogenous Amh transcription. We used a CRISPR/Cas9-based approach to specifically inactivate or delete the sole GATA-binding motif of the proximal mouse Amh promoter. AMH mRNA and protein levels were assessed at developmental time points corresponding to elevated AMH levels: fetal and neonate testes in males and adult ovaries in females. In males, loss of GATA binding to the Amh promoter significantly reduced Amh expression. Although the loss of GATA binding did not block the initiation of Amh transcription, AMH mRNA and protein levels failed to upregulate in the developing fetal and neonate testis. Interestingly, adult male mice presented no anatomical anomalies and had no evidence of retained Müllerian duct structures, suggesting that AMH levels, although markedly reduced, were sufficient to masculinize the male embryo. In contrast to males, GATA binding to the Amh promoter was dispensable for Amh expression in the adult ovary. These results provide conclusive evidence that in males, GATA4 is a positive modulator of Amh expression that works in concert with other key transcription factors to ensure that the Amh gene is sufficiently expressed in a correct spatiotemporal manner during fetal and prepubertal testis development.

Follicle loss and PTEN/PI3K/mTOR signaling pathway activated in LepR-mutated mice

Female mice (Y123F) with substitution mutations introduced through homologous gene targeting, replacing the three tyrosine residues of LepR, Tyr985, Tyr1077, and Tyr1138 with phenylalanine, could induce infertility. This study aimed to describe the reproductive alteration and to explore its mechanism. We compared the reproductive characteristics in the female homozygous (HOM) Y123F mice and wild-type (WT) littermates, analyzing the expression of downstream molecules of LepR, like protein kinase B (Akt)/mammalian target of rapamycin (mTOR), phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and insulin receptor substrate (IRS) in the ovaries. The results showed that 10-week old female Y123F HOM exhibited no reproductive periods, declined anti-mullerian hormone (AMH) levels in the serum and ovaries, reduced primordial follicles, primary follicles, secondary follicles, antral follicles and hardly no corpus lutea (all p < .05). The phosphorylation of downsream Akt, mTOR, S6K1 and eIF4B of LepR were all elevated in the ovaries of the mutated female mice. They also presented a decreased phosphorylation of IRS-1, IRS-2, and PTEN, and a strengthened phosphorylation of FOXO-3A in the ovaries. In conclusions, LepR mutation could result in follicle loss and activation of PTEN/PI3K/Akt/mTOR pathway in adult female mice, independent of insulin signaling pathway.

Identification of microRNAs in granulosa cells from patients with different levels of ovarian reserve function and the potential regulatory function of miR-23a in granulosa cell apoptosis

This study aimed to determine the microRNA (miRNA) profiles in granulosa cells (GCs) from the follicular fluid (FF) of patients with varying levels of ovarian reserve function. We included 45 women undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment. After collecting GCs from each patient, total RNA was extracted from 12 samples. Using Illumina/deep-sequencing technology, we analyzed the small RNAs in each group. Using the R package, we identified the differentially expressed (DE) miRNAs among patients with varying levels of ovarian reserve function. We identified 20 conserved and 3 novel miRNAs that were upregulated in the poor ovarian response (POR) group and 30 conserved miRNAs and 1 novel miRNA that were upregulated in the polycystic ovary syndrome (PCOS) group. Bioinformatics analysis revealed complementary pairing between miR-23a and the 3'-untranslated region (UTR) of the Sirt1 mRNA. miR-23a can regulate SIRT1 protein expression at the posttranscriptional level in GCs. Overexpressing miR-23a can inhibit the expression of SIRT1, decrease the stimulatory effect of SIRT1 on the ERK1/2 pathway, inhibit the expression of p-ERK1/2, and increase apoptosis in GCs. Previous studies confirmed that miR-23a targets SIRT1 and promotes apoptosis in GCs by inhibiting the ERK1/2 signaling pathway. This study provides a novel perspective regarding the role of miRNAs in the regulation of human GC apoptosis in vitro.

Oocyte-Derived Factors (GDF9 and BMP15) and FSH Regulate AMH Expression Via Modulation of H3K27AC in Granulosa Cells

Anti-Müllerian hormone (AMH) produced by ovarian granulosa cells (GCs) plays a crucial role in ovarian function. It is used as a diagnostic and/or prognostic marker of fertility as well as for pathophysiological conditions in women. In this study, we investigated the underlying mechanism for regulation of AMH expression in GCs using primary mouse GCs and a human GC tumor-derived KGN cell line. We find that growth differentiation factor 9 (GDF9) and bone morphogenetic factor 15 (BMP15) together (GDF9 + BMP15), but not when tested separately, significantly induce AMH expression in vitro and in vivo (serum AMH). Our results show that GDF9 + BMP15 through the PI3K/Akt and Smad2/3 pathways synergistically recruit the coactivator p300 on the AMH promoter region that promotes acetylation of histone 3 lysine 27 (H3K27ac), facilitating AMH/Amh expression. Intriguingly, we also find that FSH inhibits GDF9 + BMP15-induced increase of AMH/Amh expression. This inhibition occurs through FSH-induced protein kinase A/SF1-mediated expression of gonadotropin inducible ovarian transcription factor 1, a transcriptional repressor, that recruits histone deacetylase 2 to deacetylate H3K27ac, resulting in the suppression of AMH/Amh expression. Furthermore, we report that ovarian Amh mRNA levels are significantly higher in Fshβ-null mice (Fshβ-/-) compared with those in wild-type (WT) mice. In addition, ovarian Amh mRNA levels are restored in Fshβ-null mice expressing a human WT FSHβ transgene (FSHβ-/-hFSHβWT). Our study provides a mechanistic insight into the regulation of AMH expression that has many implications in female reproduction/fertility.

The local regulation of folliculogenesis by members of the transforming growth factor superfamily and its relevance for advanced breeding programmes

Regulation of the growth and maturation of the ovarian follicle is critical for normal reproductive function. Alterations in this growth can lead to pathological conditions, such as cystic follicles, reduced oocyte quality, or an abnormal endocrine environment leading to poor fertility. Alterations in follicular growth also influence the number of follicles ovulating and thus can change litter size. Both endocrine factors, such as follicle stimulating hormone and luteinizing hormone, as well as local factors, are known to regulate follicular growth and development. This review will focus on the role of local factors in regulation of ovarian follicular growth in ruminants, with a focus on members of the transforming growth factor superfamily. The potential role of these factors in regulating proliferation, apoptosis, steroidogenesis and responsiveness to gonadotrophins will be considered.

Endometriosis and in vitro fertilisation

The aim of the present review was to discuss a matter of concern in the clinical field of obstetrics/gynecology, namely the potency of in vitro fertilization (IVF) in the management of endometriosis-associated infertility. Endometriosis is a medical condition affecting one tenth of women in their fertile years, and accounts for up to 50% of infertile women. Thus, such high prevalence has established the necessity for investigating the effectiveness of available techniques in eradicating the disease and constraining infertility as well as the accompanying pain symptoms of endometriosis. The underlying mechanisms connecting endometriosis with low fecundity have been extensively studied, both in terms of genetic alterations and epigenetic events that contribute to the manifestation of an infertility phenotype in women with the disease. Several studies have dealt with the impact of IVF in pregnancy rates (PRs) on patients with endometriosis, particularly regarding women who wish to conceive. Results retrieved from studies and meta-analyses depict a diverse pattern of IVF success, underlining the involvement of individual parameters in the configuration of the final outcome. The ultimate decision on undergoing IVF treatment should be based on objective criteria and clinicians' experience, customized according to patients' individual needs.

Anti-Müllerian hormone overexpression restricts preantral ovarian follicle survival

Anti-Müllerian hormone (AMH) is an ovarian regulator that affects folliculogenesis. AMH inhibits the developmental activation of the dormant primordial follicles and the oocyte within. In more mature follicles, AMH reduces granulosa cell sensitivity to follicle-stimulating hormone (FSH). We examined the effects of AMH overexpression on the stages of ovarian folliculogenesis, and the development of embryos, with a transgenic mouse that overexpresses human AMH in central nervous system neurons under the control of the mouse Thy1.2 promoter (Thy1.2-AMHTg mice). These mice are severely sub-fertile, despite relatively normal ovulation rates. The embryos of Thy1.2-AMHTg females exhibited delayed preimplantation development and extensive mid-gestation fetal resorption. Young Thy1.2-AMHTg mouse ovaries exhibited only a slight reduction in the rate of primordial follicle activation but large declines in the number of developing follicles surviving past the primary stage. It was expected that Thy1.2-AMHTg mice would retain more primordial follicles as they aged, but at 5 months, their number was significantly reduced relative to wild-type females. These data indicate that moderate elevations in AMH levels can severely restrict reproductive output and the number of developing follicles in the ovary. This evidence suggests that early antral follicles are a target for AMH signaling, which may regulate early follicle survival.

Ovarian Reserve Assessment in Celiac Patients of Reproductive Age

Background

This study aimed to investigate ovarian reserve in patients of reproductive age with Celiac disease (CD) using anti-Müllerian hormone (AMH) levels, antral follicle counts (AFCs), and ovarian volume.

Material/Methods

We included into this study 46 CD female patients and 40 healthy female subjects of reproductive age, ages 18–45 years. Venous blood samples were taken from both groups on days 2–4 of the menstrual cycle, and follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂), prolactin (PRL), and AMH levels were measured. On the same day, AFCs and ovarian volumes were determined. Data on body mass index (BMI), gravidity/parity/abortions/alive counts, disease duration, and Marsh histological classification were recorded.

Results

There were no statistically significant differences between CD and control groups in terms of mean age, BMI, or median gravidity/parity/abortions/alive counts (p>0.05). Also, there were no statistically significant differences between the 2 groups in terms of mean FSH, LH, E₂, PRL levels, right and left ovarian volumes, and median right and left ovarian AFCs (p>0.05). However, AMH level was significantly lower in the CD group (p=0.032). No statistically significant correlation was found between AMH levels and age, BMI, FSH, LH, E₂, PRL levels, right and left ovarian volumes, right and left ovarian AFCs, or Marsh histological classification using the Spearman correlation test (p>0.05). However, an inverse correlation was detected showing that AMH levels decrease with increasing CD duration (r=−0.054, p=0.001).

Conclusions

We found that AMH level and ovarian reserve was decreased in CD patients of reproductive age compared to healthy controls, and that AMH level and ovarian reserve decreased with increasing disease duration in CD patients.

Untapped Reserves: Controlling Primordial Follicle Growth Activation

Even with the benefit of assisted reproductive technologies (ART), many women are unable to conceive and deliver healthy offspring. One common cause of infertility is the inability to produce eggs capable of contributing to live birth. This can occur despite standard-of-care treatment to maximize the recovery of eggs from growing ovarian follicles. Dormant primordial follicles in the human ovary are a 'reserve ' that can be exploited clinically to overcome this problem. We discuss how controlling primordial follicle growth activation (PFGA) can produce increased numbers of high-quality eggs available for fertility treatment(s). We consider the state of the art in interventions used to control PFGA, and consider genetic and epigenetic strategies on the horizon that might improve compromised oocyte quality to increase live births.

The importance of DNA repair for maintaining oocyte quality in response to anti-cancer treatments, environmental toxins and maternal ageing

BACKGROUND

Within the ovary, oocytes are stored in long-lived structures called primordial follicles, each comprising a meiotically arrested oocyte, surrounded by somatic granulosa cells. It is essential that their genetic integrity is maintained throughout life to ensure that high quality oocytes are available for ovulation. Of all the possible types of DNA damage, DNA double-strand breaks (DSBs) are considered to be the most severe. Recent studies have shown that DNA DSBs can accumulate in oocytes in primordial follicles during reproductive ageing, and are readily induced by exogenous factors such as γ-irradiation, chemotherapy and environmental toxicants. DSBs can induce oocyte death or, alternatively, activate a program of DNA repair in order to restore genetic integrity and promote survival. The repair of DSBs has been intensively studied in the context of meiotic recombination, and in recent years more detail is becoming available regarding the repair capabilities of primordial follicle oocytes.

OBJECTIVE AND RATIONALE

This review discusses the induction and repair of DNA DSBs in primordial follicle oocytes.

SEARCH METHODS

PubMed (Medline) and Google Scholar searches were performed using the key words: primordial follicle oocyte, DNA repair, double-strand break, DNA damage, chemotherapy, radiotherapy, ageing, environmental toxicant. The literature was restricted to papers in the English language and limited to reports in animals and humans dated from 1964 until 2017. The references within these articles were also manually searched.

OUTCOMES

Recent experiments in animal models and humans have provided compelling evidence that primordial follicle oocytes can efficiently repair DNA DSBs arising from diverse origins, but this capacity may decline with increasing age.

WIDER IMPLICATIONS

Primordial follicle oocytes are vulnerable to DNA DSBs emanating from endogenous and exogenous sources. The ability to repair this damage is essential for female fertility. In the long term, augmenting DNA repair in primordial follicle oocytes has implications for the development of novel fertility preservation agents for female cancer patients and for the management of maternal ageing. However, further work is required to fully characterize the specific proteins involved and to develop strategies to bolster their activity.

Regulation of AMH by oocyte-specific growth factors in human primary cumulus cells

The regulation of AMH production by follicular cells is poorly understood. The purpose of this study was to determine the role of the oocyte-secreted factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), on AMH production in primary human cumulus cells. Cumulus cells from IVF patients were cultured with a combination of GDF9, BMP15, recombinant FSH and specific signaling inhibitors. Stimulation with GDF9 or BMP15 separately had no significant effect on AMH mRNA levels. In contrast, simultaneous stimulation with GDF9 and BMP15 (G + B) resulted in a significant increase in AMH mRNA expression. Increasing concentration of G + B (0.6, 2.5, 5 and 10 ng/mL) stimulated AMH in a dose-dependent manner, showing a maximal effect at 5 ng/mL. Western blot analyses revealed an average 16-fold increase in AMH protein levels in cells treated with G + B when compared to controls. FSH co-treatment decreased the stimulation of AMH expression by G + B. The stimulatory effect of G + B on the expression of AMH was significantly decreased by inhibitors of the SMAD2/3 signaling pathway. These findings show for the first time that AMH production is regulated by oocyte-secreted factors in primary human cumulus cells. Moreover, our novel findings establish that the combination of GDF9 + BMP15 potently stimulates AMH expression.