Reproductive and metabolic determinants of granulosa cell dysfunction in normal-weight women with polycystic ovary syndrome

Bisphenol A and its structural analogues exhibit differential potential to induce mitochondrial dysfunction and apoptosis in human granulosa cells

Bisphenol A (BPA) is an endocrine disruptor strongly associated with ovarian dysfunction. BPA is being substituted by structurally similar chemicals, such as bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF). However, the toxicity of these analogues in female reproduction remains largely unknown. This study evaluated the effects of BPA and its analogues BPS, BPF, and BPAF on the mitochondrial mass and function, oxidative stress, and their potential to induce apoptosis of human granulosa cells (KGN cells). BPA and its analogues, especially BPA and BPAF, significantly decreased mitochondrial activity and cell viability. The potential of bisphenols to reduce mitochondrial mass and function differed in the following order: BPAF > BPA > BPF > BPS. Flow cytometry revealed that exposure to bisphenols significantly increased mitochondrial ROS levels and increased mitochondrial Ca2+ levels. Thus, bisphenols exposure causes mitochondrial stress in KGN cells. At the same time, bisphenols exposure significantly induced apoptosis. These results thus emphasize the toxicity of these bisphenols to cells. Our study suggests the action mechanism of BPA and its analogues in damage caused to ovarian granulosa cells. Additionally, these novel analogues may be regrettable substitutes, and the biological effects and potential risks of BPA alternatives must be evaluated.

Protective Effects of Boric Acid Taken in Different Ways on Experimental Ovarian İschemia and Reperfusion

Ovarian ischemia is a gynecological emergency that occurs as a result of ovarian torsion, affects women of reproductive age, and reduces ovarian reserve. The current study was designed to investigate the effect of boric acid taken in different ways on histopathological changes, autophagy, oxidative stress, and DNA damage caused by ischemia and reperfusion in the ovary of adult female rats. We established seven groups of 70 adult female rats: untreated control, intraperitoneal boric acid group (IpBA), oral boric acid group (OBA), ischemia/reperfusion group (ischemia/2 h reperfusion; OIR), ischemia/reperfusion and local boric acid group (OIR + LBA), ischemia/reperfusion and intraperitoneal boric acid group (OIR + IpBA), and ischemia/reperfusion and oral boric acid group (OIR + OBA). On the 31st day of the experimental procedure, both ovaries were harvested for histologic (hematoxylen and eosin and Masson trichrom), biochemical (ELISA and AMH, MDA, SOD, and CAT analyses), and comet evaluation. In the OIR group, hemorrhage, edema, inflammation, and diminished follicle reserve were seen in the ovary. Boric acid treatment reduced the ovarian ischemia/reperfusion damage, and the follicles exhibited similar morphological features to the control group. Moreover, boric acid treatment decreased the levels of Hsp70, NF-KB, COX-2, and CD31, which increased as a result of OIR. On the other hand, SCF and AMH levels, which decreased as a result of OIR, increased with boric acid treatment. The levels of autophagy markers (Beclin-1, LC3, and p62) reached values close to those of the control group. According to the biochemical findings, it was concluded that boric acid is also effective on oxidative stress, and the AMH level was particularly high in the OIR + OBA group, consistent with the immunohistochemical staining result. In addition, it was observed that the DNA damage caused by OIR reached values close to those of the control group, especially in the OBA after OIR. This study showed the therapeutic effects of boric acid on OIR injuries; thus, boric acid may be a potential therapeutic agent for ovarian protection and fertility preservation in cases that may cause ovarian torsion.

Plasma exosomes and contained MiRNAs affect the reproductive phenotype in polycystic ovary syndrome

Anovulation is the main feature of infertile women with polycystic ovary syndrome (PCOS), and there is very limited understanding of the role of plasma exosomes and miRNAs in it. To identify the effect of PCOS patients' plasma exosomes and exosomal miRNAs, we isolated plasma exosomes of PCOS patients and normal women and injected into 8-week-old ICR female mice via tail vein. The changes in estrus cycle, serum hormone levels, and ovarian morphology were observed. KGN cells were cultured and transfected with mimics and inhibitors of differentially expressed exosomal miRNAs (miR-18a-3p, miR-20b-5p, miR-106a-5p, miR-126-3p, and miR-146a-5p) and then tested for steroid hormone synthesis, proliferation, and apoptosis. The results showed that female ICR mice injected with plasma exosomes from PCOS patients presented ovarian oligo-cyclicity. Hormone synthesis and proliferation of granulosa cells were affected by differentially expressed PCOS plasma-derived exosomal miRNAs, of which miR-126-3p having the most evident effect. MiR-126-3p affected the proliferation of granulosa cells by inhibiting PDGFRβ and its downstream PI3K-AKT pathway. Our results demonstrated plasma exosomes and contained miRNAs in PCOS patients affect the estrus cycle of mice, hormone secretion, and proliferation of granulosa cells. This study provides a novel understanding about the function of plasma exosomes and exosomal miRNAs in PCOS.

Gonadotropins as pharmacological agents in assisted reproductive technology and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy associated with subfertility/infertility and pregnancy complications. Most PCOS women opt for assisted reproductive technologies (ART) for successful conception; however, optimization of the relative doses of the gonadotropins [follicle-stimulating hormone (FSH), luteinizing hormone (LH)/human chorionic gonadotropin (hCG)] for appropriate steroidogenesis, without causing ovarian hyperstimulatory syndrome (OHSS), is challenging. Embryonic factors probably do not contribute to pregnancy loss in PCOS women, albeit hormonal imbalance impairs the metabolic microenvironment critical for oocyte maturation and endometrial receptivity. Certain clinical studies have confirmed the role of metabolic corrections in increasing the rate of pregnancy in PCOS women. This review focuses on the impact of untimely high LHCGR and/or LH levels on oocyte/embryo quality, pregnancy outcomes in ART, and exploring LHCGR as a potential drug target in PCOS women.

Ovarian response to follicle-stimulating hormone in women with polycystic ovary syndrome is diminished compared to ovulatory controls

OBJECTIVE

The mechanisms underlying ovarian dysfunction in polycystic ovary syndrome (PCOS) have not been definitively established. Our objective was to perform a detailed examination of ovarian responses to recombinant follicle-stimulating hormone (rFSH) in women with PCOS and controls.

DESIGN

This prospective, crossover, dose-response study included three rFSH stimulation periods. Each stimulation period involved three consecutive, daily, subcutaneous injections of rFSH administered at a single dose. Low, medium and high rFSH doses were weight-adjusted, corresponding to 0.5, 1.1 and 2.2 IU/kg/d, respectively. Stimulation periods occurred in randomized order and were separated by 8-week washouts.

PATIENTS

Thirty participants (8 PCOS and 22 controls) were studied. PCOS was defined by oligomenorrhea and clinical or biochemical androgen excess, excluding other aetiologies of ovulatory dysfunction.

MEASUREMENTS

Blood samples were obtained for hormone measurements before and 24 h after each rFSH injection.

RESULTS

Participants with PCOS had significantly greater body mass index, antral follicle count and circulating testosterone, anti-mullerian hormone (AMH) and luteinizing hormone concentrations compared with controls participants. Baseline estradiol (E2) concentrations were similar in both groups. At the lowest dose of rFSH, PCOS participants did not demonstrate E2 increments, whereas a significant increase occurred in controls. rFSH-induced E2 production per follicle was significantly reduced in PCOS participants compared with controls at all rFSH doses. Increasing T and decreasing AMH concentrations were associated with augmented E2 production per follicle.

COONCLUSIONS

Women with PCOS exhibited diminished initial E2 responses to rFSH compared with controls. These findings suggest that the mechanism of anovulation in PCOS may involve altered ovarian response to gonadotropins.

The sex-specific difference in singleton birth weight after frozen embryo transfer compared with fresh embryo transfer: a secondary analysis of 3 randomized trials

OBJECTIVE

To assess whether the between-group difference in singleton birth weight following frozen vs. fresh embryo transfer varied with infant sex.

DESIGN

A post hoc exploratory secondary analysis of data from three multicenter randomized trials compared the live birth rates between freeze-only vs. fresh embryo transfer.

SETTING

Academic fertility centers.

PATIENT(S)

A total of 1,886 women who achieved singleton live birth after a frozen or fresh embryo transfer during these trials were included.

INTERVENTION(S)

Women underwent either a frozen or fresh embryo transfer.

MAIN OUTCOME MEASURE(S)

Mean birth weight, large for gestational age (LGA), and small for gestational age (SGA).

RESULT(S)

There was an interaction between the types of embryo transfer and infant sex on the birth weight and on the incidences of LGA and SGA. Among male infants, compared with singletons following fresh embryo transfer, singletons following frozen embryo transfer had higher mean birth weights (3,520.6 ± 526.1 vs. 3,345.1 ± 524.9 g), a higher risk of being LGA (25.2% vs. 15.7%), and a lower risk of being SGA (3.3% vs. 6.1%). However, among the female infants, no statistically significant difference was found in the mean birth weight (3,336.5 ± 514.8 vs. 3,299.5 ± 485.0 g) or the risks of being LGA (18.8% vs. 15.7%) or SGA (5.2% vs. 6.0%) between frozen and fresh embryo transfer.

CONCLUSION(S)

Male singletons born after frozen embryo transfer were more likely to have a higher birth weight than those born after fresh embryo transfer.

Anti-Müllerian Hormone Predictive Levels to Determine The Likelihood of Ovarian Hyper-Response in Infertile Women with Polycystic Ovarian Morphology

BACKGROUND

The objective of this study was to investigate serum levels of anti-Müllerian hormone (AMH) in normal-ovulatory infertile women with polycystic ovarian morphology (PCOM) and their association with ovarian hyper-response.

MATERIALS AND METHODS

This prospective cohort study was carried out on 100 infertile women with PCOM who were treated with an antagonist/agonist triggered stimulation protocol at Shahid Akbar-Abadi Hospital IVF Centre, Tehran, Iran. Serum AMH levels were measured before starting the assisted reproductive technology (ART) cycle and the ovarian hyper-response was evaluated by retrieved oocyte numbers, ooestradiol levels on the triggering day, and the incidence of ovarian hyper-stimulation syndrome (OHSS) clinical signs and symptoms. Logistic regression and the area under the curve (AUC) were used to estimate the effects of AMH and the accuracy of the test.

RESULTS

Receiver operating characteristic (ROC) curve analysis showed that AMH could significantly predict ovarian hyper-response in PCOM patients (AUC=0.73). The estimated threshold value was 4.95 ng/ml, with a specificity of 74.58% (95% confidence interval [CI]: 50.85, 93.22) and sensitivity of 73.17% (95% CI: 48.78, 92.68). Logistic regression results showed a significant interaction between AMH and body mass index (BMI, P=0.008), which indicated that BMI had a moderation effect.

CONCLUSION

Individualized stimulation protocols for patients with isolated PCOM and AMH greater than 4.95 ng/ml may significantly reduce the chances of developing OHSS. However, the AMH cut-off values to predict ovarian hyperresponse differ for different BMI categories among PCOM patients; thus, it becomes a more precise predictive marker with increasing BMI.

The Goto-Kakizaki rat is a spontaneous prototypical rodent model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by an oligo-anovulation, hyperandrogenism and polycystic ovarian morphology combined with major metabolic disturbances. However, despite the high prevalence and the human and economic consequences of this syndrome, its etiology remains unknown. In this study, we show that female Goto-Kakizaki (GK) rats, a type 2 diabetes mellitus model, encapsulate naturally all the reproductive and metabolic hallmarks of lean women with PCOS at puberty and in adulthood. The analysis of their gestation and of their fetuses demonstrates that this PCOS-like phenotype is developmentally programmed. GK rats also develop features of ovarian hyperstimulation syndrome. Lastly, a comparison between GK rats and a cohort of women with PCOS reveals a similar reproductive signature. Thus, this spontaneous rodent model of PCOS represents an original tool for the identification of the mechanisms involved in its pathogenesis and for the development of novel strategies for its treatment.

Direct impact of gonadotropins on glucose uptake and storage in preovulatory granulosa cells: Implications in the pathogenesis of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is often associated with higher levels of LH, and arrested ovarian follicular growth. The direct impact of high LH on FSH mediated metabolic responses in PCOS patients is not clearly understood.

METHOD

In order to investigate the impact of FSH and LH on glucose metabolism in preovulatory granulosa cells (GCs), we used [U¹⁴C]-2 deoxyglucose, D-[U¹⁴C]-glucose or 2-NBD glucose to analyse glucose uptake and its incorporation into glycogen. To reproduce the high androgenic potential in PCOS patients, we administered hCG both in vitro and in vivo. The role of IRS-2/PI3K/Akt2 pathway was studied after knockdown with specific siRNA. Immunoprecipitation and specific assays were used for the assessment of IRS-2, glycogen synthase and protein phosphatase 1. Furthermore, we examined the in vivo effects of hCG on FSH mediated glycogen increase in normal and PCOS rat model. HEK293 cells co-expressing FSHR and LHR were used to demonstrate glucose uptake and BRET change by FSH and hCG.

RESULTS

In normal human and rat granulosa cells, FSH is more potent than hCG in stimulating glucose uptake, however glycogen synthesis was significantly upregulated only by FSH through increase in activity of glycogen synthase via IRS-2/PI3K/Akt2 pathway. On the contrary, an impaired FSH-stimulated glucose uptake and glycogen synthesis in granulosa cells of PCOS-patients indicated a selective defect in FSHR activation. Further, in normal human granulosa cells, and in immature rat model, the impact of hCG on FSH responses was such that it inhibited the FSH-mediated glucose uptake as well as glycogen synthesis through inhibition of FSH-stimulated IRS-2 expression. These findings were further validated in HEK293 cells overexpressing Flag-LHR and HA-FSHR, where high hCG inhibited the FSH-stimulated glucose uptake. Notably, an increased BRET change was observed in HEK293 cells expressing FSHR-Rluc8 and LHR-Venus possibly suggesting increased heteromerization of LHR and FSHR in the presence of both hCG and FSH in comparison to FSH or hCG alone.

CONCLUSION

Our findings confirm a selective attenuation of metabolic responses to FSH such as glucose uptake and glycogen synthesis by high activation level of LHR leading to the inhibition of IRS-2 pathway, resulting in depleted glycogen stores and follicular growth arrest in PCOS patients.

Mechanisms of intergenerational transmission of polycystic ovary syndrome

Developmental origins of adult disease (DoHAD) refers to critical gestational ages during human fetal development and beyond when the endocrine metabolic status of the mother can permanently program the physiology and/or morphology of the fetus, modifying its susceptibility to disease after birth. The aim of this review is to address how DoHAD plays an important role in the phenotypic expression of polycystic ovary syndrome (PCOS), the most common endocrinopathy of women characterized by hyperandrogenism, oligo-anovulation and polycystic ovarian morphology. Clinical studies of PCOS women are integrated with findings from relevant animal models to show how intergenerational transmission of these central components of PCOS are programmed through an altered maternal endocrine-metabolic environment that adversely affects the female fetus and long-term offspring health. Prenatal testosterone treatment in monkeys and sheep have been particularly crucial in our understanding of developmental programming of PCOS because organ system differentiation in these species, as in humans, occurs during fetal life. These animal models, along with altricial rodents, produce permanent PCOS-like phenotypes variably characterized by LH hypersecretion from reduced steroid-negative feedback, hyperandrogenism, ovulatory dysfunction, increased adiposity, impaired glucose-insulin homeostasis and other metabolic abnormalities. The review concludes that DoHAD underlies the phenotypic expression of PCOS through an altered maternal endocrine-metabolic environment that can induce epigenetic modifications of fetal genetic susceptibility to PCOS after birth. It calls for improved maternal endocrine-metabolic health of PCOS women to lower their risks of pregnancy-related complications and to potentially reduce intergenerational susceptibility to PCOS and its metabolic derangements in offspring.

Altered m6 A modification is involved in up-regulated expression of FOXO3 in luteinized granulosa cells of non-obese polycystic ovary syndrome patients

The pathophysiology of polycystic ovary syndrome (PCOS) is characterized by granulosa cell (GC) dysfunction. m⁶A modification affects GC function in patients with premature ovarian insufficiency (POI), but the role of m⁶A modification in PCOS is unknown. The purpose of the prospective comparative study was to analyse the m⁶A profile of the luteinized GCs from normovulatory women and non‐obese PCOS patients following controlled ovarian hyperstimulation. RNA m⁶A methylation levels were measured by m⁶A quantification assay in the luteinized GCs of the controls and PCOS patients. Then, m⁶A profiles were analysed by methylated RNA immunoprecipitation sequencing (MeRIP‐seq). We reported that the m⁶A level was increased in the luteinized GCs of PCOS patients. Comparative analysis revealed differences between the m⁶A profiles from the luteinized GC of the controls and PCOS patients. We identified FOXO3 mRNA with reduced m⁶A modification in the luteinized GCs of PCOS patients. Selectively knocking down m⁶A methyltransferases or demethylases altered expression of FOXO3 in the luteinized GCs from the controls, but did not in PCOS patients. These suggested an absence of m⁶A‐mediated transcription of FOXO3 in the luteinized GCs of PCOS patients. Furthermore, we demonstrated that the involvement of m⁶A in the stability of the FOXO3 mRNA that is regulated via a putative methylation site in the 3’‐UTR only in the luteinized GCs of the controls. In summary, our findings showed that altered m⁶A modification was involved in up‐regulated expression of FOXO3 mRNA in the luteinized GCs from non‐obese PCOS patients following controlled ovarian hyperstimulation.

Animal Models to Understand the Etiology and Pathophysiology of Polycystic Ovary Syndrome

More than 1 out of 10 women worldwide are diagnosed with polycystic ovary syndrome (PCOS), the leading cause of female reproductive and metabolic dysfunction. Despite its high prevalence, PCOS and its accompanying morbidities are likely underdiagnosed, averaging > 2 years and 3 physicians before women are diagnosed. Although it has been intensively researched, the underlying cause(s) of PCOS have yet to be defined. In order to understand PCOS pathophysiology, its developmental origins, and how to predict and prevent PCOS onset, there is an urgent need for safe and effective markers and treatments. In this review, we detail which animal models are more suitable for contributing to our understanding of the etiology and pathophysiology of PCOS. We summarize and highlight advantages and limitations of hormonal or genetic manipulation of animal models, as well as of naturally occurring PCOS-like females.