Insights into hypothalamic-pituitary dysfunction in polycystic ovary syndrome

Adipokines level in plasma, hypothalamus, ovaries and adipose tissue of rats with polycystic ovary syndrome

RESEARCH QUESTION

Do the levels of adipokines (adiponectin, apelin, chemerin and vaspin) in plasma, hypothalamus, ovaries and periovarian adipose tissue differ during polycystic ovarian syndrome (PCOS)?

DESIGN

The PCOS was induced in rats by oral administration of non-steroidal aromatase inhibitor letrozole. To determine the plasma levels of adiponectin, apelin, chemerin and vaspin enzyme-linked immunosorbent assays were carried out. To assess the expression (gene and protein) and immunolocalization of these adipokines and their receptors, namely Adipor1 and Adipor2 for adiponectin, Aplnr for apelin, Ccrl2, Cmklr1 and Gpr1 for chemerin and Grp78 for vaspin in the hypothalamus, real-time polymerase chain reaction, and Western blot and immunohistochemistry were used to analyse ovaries and periovarian adipose tissue respectively.

RESULTS

In PCOS, the plasma level of adiponectin decreased (P = 0.0003), whereas apelin, chemerin and vaspin increased (P ≤ 0.0479). Moreover, PCOS modulates the expression of adipokines and their receptors in the hypothalamus, ovaries and periovarian adipose tissue compared with healthy rats (P ≤ 0.487).

CONCLUSIONS

A strong relationship was found between PCOS and adipokines, which suggests that adipokines may be a biomarker of PCOS.

The Relationship between Thyroid Hormones and Insulin Resistance in Polycystic Ovary Syndrome Women

OBJECTIVE

This study aimed to investigate the changes in thyroid hormones in the serum of patients with polycystic ovary syndrome (PCOS) and their correlation with insulin resistance.

DESIGN

This is a retrospective study.

PARTICIPANTS

84 patients having insulin resistance and 76 patients without insulin resistance were included. 90 women without history of PCOS were selected as a healthy control group.

SETTINGS

This study was conducted at Shijiazhuang Fourth Hospital.

METHODS

Blood samples were collected from each group on days 3-5 of their menstrual cycle, and their triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) levels were analyzed and compared between groups.

RESULTS

We investigated the changes of serum thyroid hormones in patients with PCOS and their correlation with insulin resistance. We found that serum levels of T3 and T4 were significantly decreased, while TSH levels were significantly increased in PCOS patients compared with HCs. Moreover, we found that patients with insulin resistance had significantly lower levels of serum T3 and T4 and higher levels of TSH compared to those PCOS participants without insulin resistance.

LIMITATIONS

This study was a retrospective and single-center study, which had selection bias, information bias, and confounding variables may affect the accuracy and reliability of the conclusion.

CONCLUSIONS

Insulin resistance negative correlates with their serum T3, T4, and positive correlates with their TSH levels. Our results develop a combined test model with the serum T3, T4, and TSH levels for the clinical diagnosis of insulin resistance in PCOS women.

Apelin receptor modulation mitigates letrozole-induced polycystic ovarian pathogenesis in mice

AIMS

Polycystic ovarian syndrome (PCOS) is one of the most common (about 5-20%) reproductive disorders in women of reproductive age; it is characterized by polycystic ovaries, hyperandrogenism, and oligo/ anovulation. The levels and expression of ovarian adipokines are deregulated in the PCOS. Apelin is an adipokine that acts through its receptor (APJ) and is known to express in the various tissues including the ovary. It has also been suggested that apelin and APJ could be targeted as therapeutic adjuncts for the management of PCOS. However, no study has been conducted on the management of PCOS by targeting the apelin system. Thus, we aimed to evaluate its impact on combating PCOS-associated ovarian pathogenesis.

METHODS

The current work employed a letrozole-induced-hyperandrogenism PCOS-like mice model to investigate the effects of apelin13 and APJ, antagonist ML221. The PCOS model was induced by oral administration of letrozole (1 mg/kg) for 21 days. A total of four experimental groups were made, control, PCOS control, PCOS + aplein13, and PCOS + ML221. The treatment of apelin13 and ML221 was given from day 22 for two weeks.

KEY FINDINGS

The letrozole-induced PCOS-like features such as hyperandrogenism, cystic follicle, decreased corpus luteum, elevated levels of LH/FSH ratio, and up-regulation of ovarian AR expression were ameliorated by apelin13 and ML221 treatment. However, the PCOS-augmented oxidative stress and apoptosis were suppressed by apelin 13 treatments only. ML221 treatment still showed elevated oxidative stress and stimulated apoptosis as reflected by decreased antioxidant enzymes and increased active caspase3 and Bax expression. The expression of ERs was elevated in all groups except control. Furthermore, the PCOS model showed elevated expression of APJ and apelin13 treatment down-regulated its own receptor. Overall, observing the ovarian histology, corpus luteum formation, and decreased androgen levels by both apelin13 and ML221 showed ameliorative effects on the cystic ovary.

SIGNIFICANCE

Despite the similar morphological observation of ovarian histology, apelin13 and ML221 exhibited opposite effects on oxidative stress and apoptosis. Therefore, apelin13 (which down-regulates APJ) and ML221 (an APJ antagonist) may have suppressed APJ signalling, which would account for our findings on the mitigation of polycystic ovarian syndrome. In conclusion, both apelin13 and ML221 mediated mitigation have different mechanisms, which need further investigation.

Polycystic ovary syndrome and related inflammation in radiomics; relationship with patient outcome

Polycystic ovary syndrome (PCOS) refers to a condition that often has 'poly' liquid containing sacks around ovaries. It affects reproductive-aged females giving rise to menstrual and related reproductive issues. PCOS is marked by hormonal imbalance often resulting in hyperandrogenism. Inflammation is now considered a central manifestation of this disease with several inflammatory biomarkers such as TNF-α, C-reactive protein and Interleukins-6/18 found to be particularly elevated in PCOS patients. Diagnosis is often late, and MRI-based diagnosis, along with blood-based analyses, are still the best bet for a definitive diagnosis. Radiomics also offers several advantages and should be exploited to the maximum. The mechanisms of PCOS onset and progression are not very well known but pituitary dysfunction and elevated gonadotrophin releasing hormone resulting in high levels of luteinizing hormone are indicative of an activated hypothalamic-pituitary-ovarian axis in PCOS. A number of studies have also identified signaling pathways such as PI3K/Akt, NF-κB and STAT in PCOS etiology. The links of these signaling pathways to inflammation further underline the importance of inflammation in PCOS, which needs to be resolved for improving patient outcomes.

Irpex lacteus polysaccharide exhibits therapeutic potential for ovarian fibrosis in PCOS rats via the TGF-β1/smad pathway

Polycystic ovarian syndrome (PCOS) is one of the commonest endocrinopathies in childbearing women. The research was conducted to assess the impact of Irpex lacteus polysaccharide (ILP, 1000 mg/kg) on the letrozole (1 mg/kg)-induced PCOS model in female rats. Metformin (Met, 265 mg/kg) as the positive control. The study suggested that ILP restored the estrous cycle in rats with PCOS as well as lowered relative ovarian weight and body weight, in comparison to normal. Rats with PCOS showed improvement in ovarian structure and fibrosis when given ILP. ILP decreased the testosterone (T), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), luteinizing hormone (LH), homeostasis model assessment-insulin resistance (HOMA-IR), fasting blood glucose (FBG), and insulin (INS) levels and elevated the follicle-stimulating hormone (FSH) and estrogen (E2) levels in PCOS rats. In addition, ILP increased the content of superoxide dismutase (SOD) in serum and the antioxidant enzymes (Prdx3, Sod1, Gsr, Gsta4, Mgst1, Gpx3, Sod2 and Cat) expression levels in the ovaries and decreased the serum expression of malondialdehyde (MDA). In addition, ILP treatment slowed down the process of the fibrosis-associated TGF-β1/Smad pathway and downregulated α-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF) levels in PCOS rats ovaries. According to these findings, ILP may be able to treat letrozole-induced PCOS in rats by ameliorating metabolic disturbances, sex hormone levels, oxidative stress, and ovarian fibrosis.

Polycystic ovary syndrome and iron overload: biochemical link and underlying mechanisms with potential novel therapeutic avenues

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in women with components of significant genetic predisposition and possibly multiple, but not yet clearly defined, triggers. This disorder shares several clinical features with hemochromatosis, a genetically defined inheritable disorder of iron overload, which includes insulin resistance, increased adiposity, diabetes, fatty liver, infertility, and hyperandrogenism. A notable difference between the two disorders, however, is that the clinical symptoms in PCOS appear at much younger age whereas they become evident in hemochromatosis at a much later age. Nonetheless, noticeable accumulation of excess iron in the body is a common finding in both disorders even at adolescence. Hepcidin, the iron-regulatory hormone secreted by the liver, is reduced in both disorders and consequently increases intestinal iron absorption. Recent studies have shown that gut bacteria play a critical role in the control of iron absorption in the intestine. As dysbiosis is a common finding between PCOS and hemochromatosis, changes in bacterial composition in the gut may represent another cause for iron overload in both diseases via increased iron absorption. This raises the possibility that strategies to prevent accumulation of excess iron with iron chelators and/or probiotics may have therapeutic potential in the management of polycystic ovary syndrome.

Acetate restores hypothalamic-adipose kisspeptin status in a rat model of PCOS by suppression of NLRP3 immunoreactivity

PURPOSE

Polycystic ovary syndrome (PCOS) is a complex reproductive event that is delineated by endocrine/metabolic disorders. Alteration of kisspeptin status in the hypothalamus and adipose tissue is critical to increased endocrine/metabolic derangements in PCOS individuals, aggravating the clinical manifestation of PCOS and its complications. Short chain fatty acids (SCFAs) are crucial modulators of metabolic homeostasis. However, the role of SCFAs, particularly acetate on hypothalamic-adipose kisspeptin status (HAKS) in PCOS model is unknown. The present study hypothesized acetate as a key player in restoration of deranged HAKS, associated with experimental PCOS model.

METHODS

Three groups (n = 6/group) of female Wistar rats (120-150 g) were used. The groups were treated (po) for 21 days with vehicle, letrozole (1 mg/kg) with/without acetate (200 mg/kg) respectively.

RESULTS

Letrozole-treated animals had impaired glucose homeostasis, elevated testosterone, leptin and LH/FSH ratio and decreased GnRH and adiponectin with ovarian tissues revealing degenerated follicles and disrupted morphology. These animals also showed increased concentration of hypothalamic triglyceride (TG)/total cholesterol (TC), free fatty acid (FFA), and decreased concentration of TG/TC/FFA in visceral adipose tissue (VAT) with an increase in hypothalamic and VAT malondialdehyde, NF-κB/TNF-α and decreased glutathione/G6PD and hypothalamic but not VAT kisspeptin. Immunohistochemical analysis revealed the expression of NLRP3 inflammasome in the hypothalamus and VAT and all these changes were attenuated by acetate.

CONCLUSIONS

Altogether, the present results demonstrate that PCOS is characterized with hypothalamic-adipose inflammation, associated with immunohistochemical expression of NLRP3 with significant alteration of hypothalamic but not adipose kisspeptin. The results suggest that acetate restores kisspeptin status in PCOS animals. This beneficial effect is accompanied by repressed NLRP3 immunoreactivity.

The relationships of sex hormone-binding globulin, total testosterone, androstenedione and free testosterone with metabolic and reproductive features of polycystic ovary syndrome

Objective

A recent Mendelian randomization study has suggested a causal role for sex hormone‐binding globulin (SHBG), total testosterone and free testosterone in the pathogenesis of polycystic ovary syndrome (PCOS). The aim of this study was to assess the relationships of SHBG, androstenedione, total and free testosterone with the individual metabolic and reproductive features of PCOS.

Design

Cross‐sectional data in PCOS patients (n=96) prospectively collected in a secondary/tertiary clinic for menstrual cycle disorders.

Methods

Multivariable regression analyses were conducted to study the associations between SHBG, androstenedione, total and free testosterone with metabolic (BMI, waist circumference, systolic and diastolic blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and homeostatic model assessment for insulin resistance [HOMA2‐IR]) and reproductive features (menstrual cycle length, antral follicle count, anti‐Müllerian hormone, luteinizing hormone, follicle‐stimulating hormone and Ferriman‐Gallwey score) of PCOS.

Results

Serum SHBG and free testosterone, but not total testosterone or androstenedione, were significantly associated with BMI, waist circumference, serum triglycerides, HDL cholesterol, LDL cholesterol and HOMA2‐IR. The strength of the associations with serum lipids was reduced after adjustment for BMI, but not for HOMA2‐IR. Total testosterone was significantly associated with antral follicle count. SHBG, total testosterone and androstenedione were significantly associated with serum AMH. Only the strength of the association for SHBG was reduced after adjustment for BMI.

Conclusions

Serum SHBG is associated with primarily metabolic features, whereas total testosterone and androstenedione are associated with reproductive features of PCOS. These results suggest a differential underlying pathophysiology for the metabolic and reproductive features of PCOS.

Assessment of the retinal and choroidal microvascularization in polycystic ovary syndrome: an optical coherence tomography angiography study

PURPOSE

To examine the retinal, peripapillary, choroidal microvascularization and the choroid thickness (CT) of the patients with polycystic ovary syndrome (PCOS) using optical coherence tomography angiography (OCT-A) and compare the results to measurements obtained from healthy controls.

METHODS

In total, 47 eyes of 47 patients recently diagnosed with PCOS and 47 eyes of 47 age-matched healthy women were included in this study. An RT XR Avanti instrument with AngioVue software was used for the OCT-A imaging using 6 × 6 mm macular and 4.5 × 4.5 mm optic nerve head scans. Quantitative vessel density results of superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillaries (RPC); flow area and flow density of choriocapillaris; and foveal avascular zone (FAZ) area were analyzed. CT was evaluated by using the measurements obtained from the subfoveolar area.

RESULTS

No significant differences were detected between the groups for any of vessel density results for the SCP, DCP, and RPC as well as the FAZ area. The difference in the choriocapillaris flow area and flow density between the groups was not statistically significant. The choroid was significantly thicker in women with PCOS than in the healthy group (p = 0.002).

CONCLUSION

Retinal and choroidal microvascularization was comparable between the women who were evaluated early after diagnosed with PCOS and age-matched healthy controls. Choroid was found thicker in patients with PCOS than in healthy women. OCT-A, as a new and noninvasive imaging method, may help in understanding the effect of PCOS on the posterior segment of the eye.

Beneficial effects of minocycline on the ovary of polycystic ovary syndrome mouse model: Molecular docking analysis and evaluation of TNF-α, TNFR2, TLR-4 gene expression

Polycystic ovary syndrome (PCOS) is the most common cause of ovulatory infertility. Inflammation may be involved in the pathogenesis and development of PCOS. We investigated the anti-inflammatory effect of minocycline on TNF-α, TNFR2, and TLR4 expression levels and the key features of PCOS in a mouse model. Molecular docking was performed by Molecular Operating Environment software. PCOS was induced by estradiol valerate injection (EV) (2 mg/kg/day) in 40 mice. After 28 days, the mice were divided into five groups, including control, PCOS, minocycline control, minocycline PCOS model (50 mg/kg), and letrozole PCOS (0.5 mg/kg). The Levels of FSH, LH, E2, and testosterone were determined by ELISA. H&E staining was used for histological analysis in the ovarian tissues. Docking scores were -10.35, -10.57, and -12.45 kcal/mol for TNFα, TLR-4, and TNFR2, respectively. The expression levels of TNF-α, TNFR2, and TLR4 were detected by Real-Time PCR. PCOS models exhibited acyclicity, a significant increase in E2 levels (P < 0.01), and no difference in FSH, LH, and testosterone. The expression levels of TNF-α, TNFR2, and TLR-4 significantly increased in PCOS (2.70, 7.90, and 14.83-fold, respectively). EV treatment significantly increased graafian follicles (P < 0.001) and decreased corpus luteum (CL) (P < 0.01). Minocycline treatment in PCOS led to a significant decrease in E2 (P < 0.01) and graafian follicles (P < 0.001) and a significant increase in the CL numbers (P < 0.05). Our findings showed the positive effects of minocycline on estradiol level, CL and graafian follicles counts, suggesting that minocycline might inhibit these proteins and improve ovulation in our mouse model of PCOS.

Hypothalamic Inflammation as a Potential Pathophysiologic Basis for the Heterogeneity of Clinical, Hormonal, and Metabolic Presentation in PCOS

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. It is a heterogeneous condition characterized by reproductive, endocrine, metabolic, and psychiatric abnormalities. More than one pathogenic mechanism is involved in its development. On the other hand, the hypothalamus plays a crucial role in many important functions of the body, including weight balance, food intake, and reproduction. A high-fat diet with a large amount of long-chain saturated fatty acids can induce inflammation in the hypothalamus. Hypothalamic neurons can sense extracellular glucose concentrations and participate, with a feedback mechanism, in the regulation of whole-body glucose homeostasis. When consumed nutrients are rich in fat and sugar, and these regulatory mechanisms can trigger inflammatory pathways resulting in hypothalamic inflammation. The latter has been correlated with metabolic diseases, obesity, and depression. In this review, we explore whether the pattern and the expansion of hypothalamic inflammation, as a result of a high-fat and -sugar diet, may contribute to the heterogeneity of the clinical, hormonal, and metabolic presentation in PCOS via pathophysiologic mechanisms affecting specific areas of the hypothalamus. These mechanisms could be potential targets for the development of effective therapies for the treatment of PCOS.

Anti-Müllerian hormone as a driving force of polycystic ovary syndrome, independently from insulin resistance

RESEARCH QUESTION

Which clinical features, along with biological features, ultrasound features, or both, are the most strongly associated with either high or low anti-Müllerian hormone (AMH) levels in patients with polycystic ovary syndrome (PCOS)?

DESIGN

A retrospective cross-sectional study conducted within a university-affiliated reproductive endocrinology unit in Lille, France. A total of 639 patients with PCOS according to the Rotterdam Criteria and 137 control women were included. A comparison of clinical, hormonal, metabolic and ultrasound data in patients with PCOS and controls belonging to the first (Q1) and fourth (Q4) quartiles of their respective AMH ranges (discriminant analysis) was conducted.

RESULTS

In the PCOS group, patients in Q4 had higher LH levels and a more severe phenotype, but they were thinner and had lower levels of hyperinsulinaemia than patients in Q1. In the PCOS group, discriminant analysis yielded a highly significant model in which follicle number per ovary (FNPO) and serum LH were strongly and equally discriminating between Q4 and Q1 (R² at 0.371 and 0.304, respectively, both P < 0.0001), whereas body mass index had less, although significant, effect (R² = 0.075, P < 0.0001). In control women, discriminant analysis yielded a significant discriminant model, including only FNPO and age (R² at 0.62 and 0.27, both P < 0.0001).

CONCLUSION

High serum AMH levels are associated with high serum LH levels and more severe features of PCOS. Conversely, the effect of hyperinsulinism may be greater in patients with lower serum AMH levels, suggesting independent effects of AMH and insulin on the phenotypic expression of PCOS.

Role of Anti-Müllerian Hormone in the Pathogenesis of Polycystic Ovary Syndrome

Besides its interest for diagnosis, the finding of an elevated serum AMH level in PCOS has open major pathophysiological issues. This review addresses the three most important issues: 1- the role of AMH in the disturbed folliculogenesis of PCOS; 2- the role of AMH in the gonadotropin dysregulation of PCOS and 3- the role of AMH in the trans-generational transmission of PCOS. For each of those issues, the clinical and experimental evidences currently available are discussed and pathophysiological hypothesis are proposed.

Ovarian Function in Adolescents Conceived Using Assisted Reproductive Technologies

STUDY OBJECTIVE

To compare ovarian function between adolescents conceived using assisted reproductive technology (AcART) and adolescents who were conceived spontaneously (AcSP).

DESIGN

Multicenter study of ovarian function in AcART because of male or tubal infertility.

SETTING

University Hospital.

PARTICIPANTS

We evaluated 22 AcART and 53 AcSP at 1-2 years after menarche. The participants were born at term (≥37 weeks of gestation) with normal birth weights (≥2500 g) from singleton pregnancies.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Differences in ovulation, reproductive hormones, and ovarian morphology.

RESULTS

AcART had an older age of menarche than that of AcSP, even after adjusting for maternal age at menarche, gestational age, and birth weight (P = .027). AcART had lower incidence of ovulation (P = .021) and higher luteinizing hormone serum levels (P = .01) than those of AcSP. The incidence of oligomenorrhea and the cycle length were similar between AcART and AcSP. AcART had levels of anti-Müllerian hormone, inhibin B, follicle-stimulating hormone, estradiol, and androgens similar to those of AcSP. The ovarian morphology, ovarian volume, and follicle counts were similar in both groups.

CONCLUSION

AcART had later menarche, lower ovulation rates, and higher luteinizing hormone levels than those of AcSP. Future studies should investigate whether these findings are indicative of a risk of ovarian dysfunction later in life for AcART.

Regulation of reproduction via tight control of gonadotropin hormone levels

Mammalian reproduction is controlled by the hypothalamic-pituitary-gonadal axis. GnRH from the hypothalamus regulates synthesis and secretion of gonadotropins, LH and FSH, which then control steroidogenesis and gametogenesis. In females, serum LH and FSH levels exhibit rhythmic changes throughout the menstrual or estrous cycle that are correlated with pulse frequency of GnRH. Lack of gonadotropins leads to infertility or amenorrhea. Dysfunctions in the tightly controlled ratio due to levels slightly outside the normal range occur in a larger number of women and are correlated with polycystic ovaries and premature ovarian failure. Since the etiology of these disorders is largely unknown, studies in cell and mouse models may provide novel candidates for investigations in human population. Hence, understanding the mechanisms whereby GnRH regulates gonadotropin hormone levels will provide insight into the physiology and pathophysiology of the reproductive system. This review discusses recent advances in our understanding of GnRH regulation of gonadotropin synthesis.

Hormonal alterations in PCOS and its influence on bone metabolism

According to the World Health Organization (WHO) polycystic ovary syndrome (PCOS) occurs in 4-8% of women worldwide. The prevalence of PCOS in Indian adolescents is 12.2% according to the Indian Council of Medical Research (ICMR). The National Institute of Health has documented that it affects approximately 5 million women of reproductive age in the United States. Hormonal imbalance is the characteristic of many women with polycystic ovarian syndrome (PCOS). The influence of various endocrine changes in PCOS women and their relevance to bone remains to be documented. Hormones, which include gonadotrophin-releasing hormone (GnRH), insulin, the leutinizing/follicle-stimulating hormone (LH/FSH) ratio, androgens, estrogens, growth hormones (GH), cortisol, parathyroid hormone (PTH) and calcitonin are disturbed in PCOS women. These hormones influence bone metabolism in human subjects directly as well as indirectly. The imbalance in these hormones results in increased prevalence of osteoporosis in PCOS women. Limited evidence suggests that the drugs taken during the treatment of PCOS increase the risk of bone fracture in PCOS patients through endocrine disruption. This review is aimed at the identification of the relationship between bone mineral density and hormonal changes in PCOS subjects and identifies potential areas to study bone-related disorders in PCOS women.

c-JUN Dimerization Protein 2 (JDP2) Is a Transcriptional Repressor of Follicle-stimulating Hormone β (FSHβ) and Is Required for Preventing Premature Reproductive Senescence in Female Mice

Follicle-stimulating hormone (FSH) regulates follicular growth and stimulates estrogen synthesis in the ovaries. FSH is a heterodimer consisting of an α subunit, also present in luteinizing hormone, and a unique β subunit, which is transcriptionally regulated by gonadotropin-releasing hormone 1 (GNRH). Because most FSH is constitutively secreted, tight transcriptional regulation is critical for maintaining FSH levels within a narrow physiological range. Previously, we reported that GNRH induces FSHβ (Fshb) transcription via induction of the AP-1 transcription factor, a heterodimer of c-FOS and c-JUN. Herein, we identify c-JUN-dimerization protein 2 (JDP2) as a novel repressor of GNRH-mediated Fshb induction. JDP2 exhibited high basal expression and bound the Fshb promoter at an AP-1-binding site in a complex with c-JUN. GNRH treatment induced c-FOS to replace JDP2 as a c-JUN binding partner, forming transcriptionally active AP-1. Subsequently, rapid c-FOS degradation enabled reformation of the JDP2 complex. In vivo studies revealed that JDP2 null male mice have normal reproductive function, as expected from a negative regulator of the FSH hormone. Female JDP2 null mice, however, exhibited early puberty, observed as early vaginal opening, larger litters, and early reproductive senescence. JDP2 null females had increased levels of circulating FSH and higher expression of the Fshb subunit in the pituitary, resulting in elevated serum estrogen and higher numbers of large ovarian follicles. Disruption of JDP2 function therefore appears to cause early cessation of reproductive function, a condition that has been associated with elevated FSH in women.

Intravaginal administration of metformin hydrochloride loaded cationic niosomes amalgamated with thermosensitive gel for the treatment of polycystic ovary syndrome: In vitro and in vivo studies

BACKGROUND AND OBJECTIVE

Metformin hydrochloride (MTF-HCl) is extensively recommended by physicians for the treatment of polycystic ovary syndrome (PCOS). Mechanistically, MTF-HCl activates AMP-dependent kinase-α (AMPK-α) pathway to decrease the glucose production, enhances fatty acid oxidation and elevates the uptake of glucose in tissues. However, despite favourable physicochemical properties, oral administration of MTF-HCl is associated with impaired bioavailability (50-60%), lactic-acidosis and frequent dosing (500mg 2-3 times a day) in PCOS that ultimately influence the patient compliance. Therefore, in present investigation, MTF-HCl loaded unmodified and cationic small unilamellar niosomes were separately amalgamated with thermosensitive gel (MTF-HCl-SUNs-Gel and MTF-HCl-C-SUNs-Gel) for the treatment of PCOS through vaginal route of administration.

METHODS AND RESULTS

MTF-HCl-SUNs and MTF-HCl-C-SUNs were separately prepared by reverse phase evaporation method. The nanovesicle size and zeta-potential of MTF-HCl-C-SUNs were measured to be 210.3±14.8-nm (P<0.05) and +8.7±2.7-mV (P<0.001), significantly higher than 198.5±20.3-nm and -16.6±3.9-mV of MTF-HCl-SUNs, respectively. Moreover, promising results of in vitro characterization parameters like gelation time, gelling temperature, viscosity analysis, percent mucoadhesiveness and drug release of MTF-HCl-C-SUNs-Gel and MTF-HCl-SUNs-Gel ensured the candidature of tailored gels for further in vivo investigations. In this way, treatment of PCOS rats under scheduled dose-dosage regimen with oral MTF-HCl solution, intravaginal MTF-HCl-SUNs-Gel and intravaginal MTF-HCl-C-SUNs-gel exhibited remarkable alterations, recruitment and development of normal follicles in addition to normalization of level of various hormones in PCOS.

CONCLUSION

In conclusion, MTF-C-SUNs-Gel has paved the way for developing intravaginal dosage form of MTF-HCl for the treatment of PCOS.

Targets to treat metabolic syndrome in polycystic ovary syndrome

INTRODUCTION

Metabolic syndrome is comprised of a combination of the following states: increased insulin resistance, dyslipidemia, cardiovascular disease, and increased abdominal obesity. Women with polycystic ovary syndrome (PCOS) have an increased risk of developing metabolic syndrome over the course of their lives. Metabolic syndrome increases risk of major cardiovascular events, morbidity, quality of life, and overall health care costs. Though metabolic syndrome in women with PCOS is an area of great concern, there is no effective individual medical therapeutic to adequately treat this issue.

AREAS COVERED

This article will review key aspects of metabolic syndrome in PCOS. We will discuss classic and novel therapeutics to address metabolic syndrome in women with PCOS. We will conclude with the importance of developing strategic interventions to increase the compliance to lifestyle and dietary modification, in addition to appreciation of the emerging pharmaceutical therapeutics available.

EXPERT OPINION

Innovation in lifestyle modification, including diet, exercise, with and without dedicated stress reduction techniques is the future in treatment of metabolic syndrome in PCOS. Application of novel interventions, such as group medical care, may improve future adherence to lifestyle modification recommendations, in addition to or in combination with pharmaceutical therapeutics.

Elevated serum androstenedione is associated with a more severe phenotype in women with polycystic ovary syndrome (PCOS)

OBJECTIVE

To evaluate the impact of elevated serum Δ4A levels on the hormonal and metabolic features of the different phenotypes of PCOS.

DESIGN

1276 women with PCOS according to the Rotterdam criteria were included, in whom serum hormonal levels were determined.

RESULTS

In PCOS women as a whole, as well as in patients presenting clinical and/or biochemical hyperandrogenemia (phenotypes I and II), Δ4A levels >3.8 ng/ml were positively related to LH, LH/FSH ratio, T, DHEAS, 17 OH progesterone and FAI and negatively related to T/Δ4A ratio. In the milder phenotype III, a positive correlation between Δ4A levels >3.8 ng/ml and T, DHEAS, 17 OH progesterone and FAI and a negative one between increased Δ4A and T/Δ4A ratio were reported. In the whole PCOS group with androstenedione >3.8 ng/ml, an increased ovarian volume was observed, while a greater mean follicular number was found only in phenotypes I and II.

CONCLUSIONS

Increased serum Δ4A levels, which are associated with more severe PCOS phenotypes, possibly contribute to the worsening of PCOS features and therefore could be a valuable marker of biochemical hyperandrogenemia.

Ontogeny of the ovary in polycystic ovary syndrome

Activation of primordial follicles into the growing pool, selection of the dominant follicle, and its eventual ovulation require complex endocrine and metabolic interactions as well as intraovarian paracrine signals to coordinate granulosa cell proliferation, theca cell differentiation, and oocyte maturation. Early preantral follicle development relies mostly upon mesenchymal-epithelial cell interactions, intraovarian paracrine signals, and oocyte-secreted factors, whereas development of the antral follicle depends on circulating gonadotropins as well as locally derived regulators. In women with polycystic ovary syndrome (PCOS), ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and altered intrafollicular paracrine signaling perturb the activation, survival, growth, and selection of follicles, causing accumulation of small antral follicles within the periphery of the ovary, giving it a polycystic morphology. Altered adipocyte-ovarian interactions further compound these adverse events on follicle development and also can harm the oocyte, particularly in the presence of increased adiposity. Finally, endocrine antecedents of PCOS occur in female infants born to mothers with PCOS, which suggests that interactions between genes and the maternal-fetal hormonal environment may program ovarian function after birth.

FOXO1 transcription factor inhibits luteinizing hormone β gene expression in pituitary gonadotrope cells

Synthesis of luteinizing hormone (LH) is tightly controlled by a complex network of hormonal signaling pathways that can be modulated by metabolic cues, such as insulin. One group of candidate genes that may be regulated by insulin signaling in pituitary gonadotrope cells is the FOXO subfamily of forkhead transcription factors. In this study we investigated whether FOXO1 is expressed in gonadotropes and if it can modulate LH β-subunit (Lhb) gene expression. We demonstrated that FOXO1 is expressed in murine gonadotrope cells and that insulin signaling increased FOXO1 phosphorylation and cytoplasmic localization in a PI3K-dependent manner. We also showed that FOXO1 repressed basal transcription and gonadotropin-releasing hormone (GnRH) induction of both the murine and human LHB genes in LβT2 cells, suggesting that FOXO1 regulation of LHB transcription may be conserved between rodents and humans. Although we did not detect FOXO1 binding to the proximal Lhb promoter, the FOXO1 DNA binding domain was necessary for the suppression, suggesting that FOXO1 exerts its effect through protein-protein interactions with transcription factors/cofactors required for Lhb gene expression. FOXO1 repression mapped to the proximal Lhb promoter containing steroidogenic factor 1 (SF1), pituitary homeobox 1 (PTX1), and early growth response protein 1 (EGR1) binding elements. Additionally, FOXO1 blocked induction of the Lhb promoter with overexpressed SF1, PTX1, and EGR1, indicating that FOXO1 repression occurs via these transcription factors but not through regulation of their promoters. In summary, we demonstrate that FOXO1 phosphorylation and cellular localization is regulated by insulin signaling in gonadotropes and that FOXO1 inhibits Lhb transcription. Our study also suggests that FOXO1 may play an important role in controlling LH levels in response to metabolic cues.

Temporal window in which exposure to estradiol permanently modifies ovarian function causing polycystic ovary morphology in rats

OBJECTIVE

To investigate the developmental window in which E(2) exposure produces irreversible changes in ovarian function resulting in polycystic ovary.

DESIGN

Basic experimental study.

SETTING

University animal laboratory.

ANIMAL(S)

Thirty Sprague-Dawley rats were administered a single E(2) valerate dose (10 mg/kg of weight) at 1, 7, 14, 21, or 30 days of age. Control rats were injected with the vehicle at 1 day of age. All rats were sacrificed at 6 months of age.

INTERVENTION(S)

Observation of vaginal opening, estrous cyclicity by vaginal smears, and ovarian morphometry in the 6-month-old rat.

MAIN OUTCOME MEASURE(S)

Measurement of ovarian noradrenaline by high-performance liquid chromatography coupled with electrochemical detection, serum levels of LH by enzyme-linked immunoassay, P, androstenedione, and E(2) by enzyme immunoassay.

RESULT(S)

Rats exposed to E(2) at 1, 7, or 14 days of life did not show estrual cycling activity and maintained a polycystic ovary (PCO) condition throughout the entirety of the study. However, if the exposure to E(2) occurred after postnatal day 21, the PCO-induced condition was reversible. In rats that developed a permanent PCO condition, we observed significant effects of E(2) on ovarian morphology if exposure occurred on postnatal day 1 and a presumable effect on the hypothalamus if the exposure occurred between postnatal days 1 and 14.

CONCLUSION(S)

Our findings suggest that in rats, the most sensitive period for the promotion of an irreversible PCO morphology by estrogenic compounds is during neonatal early follicular development.

G proteins and autocrine signaling differentially regulate gonadotropin subunit expression in pituitary gonadotrope

Gonadotropin-releasing hormone (GnRH) acts at gonadotropes to direct the synthesis of the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The frequency of GnRH pulses determines the pattern of gonadotropin synthesis. Several hypotheses for how the gonadotrope decodes GnRH frequency to regulate gonadotropin subunit genes differentially have been proposed. However, key regulators and underlying mechanisms remain uncertain. We investigated the role of individual G proteins by perturbations using siRNA or bacterial toxins. In LβT2 gonadotrope cells, FSHβ gene induction depended predominantly on Gα(q/11), whereas LHβ expression depended on Gα(s). Specifically reducing Gα(s) signaling also disinhibited FSHβ expression, suggesting the presence of a Gα(s)-dependent signal that suppressed FSH biosynthesis. The presence of secreted factors influencing FSHβ expression levels was tested by studying the effects of conditioned media from Gα(s) knockdown and cholera toxin-treated cells on FSHβ expression. These studies and related Transwell culture experiments implicate Gα(s)-dependent secreted factors in regulating both FSHβ and LHβ gene expression. siRNA studies identify inhibinα as a Gα(s)-dependent GnRH-induced autocrine regulatory factor that contributes to feedback suppression of FSHβ expression. These results uncover differential regulation of the gonadotropin genes by Gα(q/11) and by Gα(s) and implicate autocrine and gonadotrope-gonadotrope paracrine regulatory loops in the differential induction of gonadotropin genes.

A single-nucleotide polymorphism in the EAP1 gene is associated with amenorrhea/oligomenorrhea in nonhuman primates

Current evidence suggests that the acquisition of female reproductive capacity and the maintenance of mature reproductive function are related processes transcriptionally regulated by gene networks operating within the neuroendocrine brain. One of these genes, termed enhanced at puberty 1 (EAP1), encodes an upstream regulator of these processes. Selective inhibition of EAP1 expression in discrete regions of the rat and nonhuman primate (NHP) hypothalamus, via targeted delivery of RNA interference, either disrupts (rats) or abolishes (monkeys) reproductive cycles. The striking loss of menstrual cyclicity resulting from knocking down hypothalamic EAP1 expression suggests that diminished EAP1 function may contribute to disorders of the menstrual cycle of neuroendocrine origin. Here we show that a single-nucleotide polymorphism in the 5'-flanking region of EAP1 gene is associated with increased incidence of amenorrhea/oligomenorrhea in NHP. In the presence of the risk allele, binding of the transcription factor mothers against decapentaplegic homolog 3 (SMAD3) to its recognition site contained within the polymorphic sequence in the monkey EAP1 promoter is reduced. The risk allele also diminishes the increase in EAP1 promoter activity elicited by TGFβ1, a peptide that activates a SMAD3/4-mediated signaling pathway to regulate gene transcription. These findings indicate that common genetic variation in the EAP1 locus increases the susceptibility of NHP to loss/disruption of menstrual cyclicity. They also raise the possibility that polymorphisms in EAP1 may increase the risk of functional hypothalamic amenorrhea in humans.

State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)

PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy.

[Physiopathological link between polycystic ovary syndrome and hyperprolactinemia: myth or reality?]

Polycystic ovary syndrome (PCOS) and hyperprolactinemia are the two most common etiologies of disorders of the cycle in women. In clinical practice, it is not unusual to find hyperprolactinemia associated with clinical, hormonal and ultrasound features of PCOS. However, currently, there is no evidence of a pathophysiological link between these two entities. Thus, this association seems to be fortuitous. Therefore, hyperprolactinemia in women with PCOS must lead to etiological investigations, including eliminating macroprolactinemia (excess of "big prolactin" and/or "big-big prolactin"). Finally, symptomatic hyperprolactinemias (excluding macroprolactinemia) can "mask" an underlying PCOS through a gonadotropic inhibition. Moreover, symptomatic hyperprolactinemias can provide clinical and ultrasound features of a "moderate" PCOS. Therefore, in agreement with the consensus of Rotterdam, PCOS must remain a diagnosis of exclusion, after eliminating symptomatic hyperprolactinemias (excluded macroprolactinemia) and all other etiologies of hyperandrogenism.

Polycystic ovary syndrome: etiology, pathogenesis and diagnosis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age, with a prevalence of up to 10%. Various diagnostic criteria have been proposed, generally centered around the features of hyperandrogenism and/or hyperandrogenemia, oligo-ovulation and polycystic ovarian morphology. Insulin resistance is present in a majority of cases, with compensatory hyperinsulinemia contributing to hyperandrogenism via stimulation of ovarian androgen secretion and inhibition of hepatic sex hormone-binding globulin production. Adipose tissue dysfunction has been implicated as a contributor to the insulin resistance observed in PCOS. Environmental and genetic factors also have a role in the development of PCOS. The syndrome is associated with numerous morbidities, including infertility, obstetrical complications, type 2 diabetes mellitus, cardiovascular disease, and mood and eating disorders. Despite these morbidities, PCOS may be common in our society owing to evolutionary advantages of the syndrome in ancient times, including smaller family sizes, reduced exposure to childbirth-related mortality, increased muscle mass and greater capacity to store energy. The diagnosis of PCOS hinges on establishing key features while ruling out other hyperandrogenic or oligo-ovulatory disorders. Treatment is focused on the goals of ameliorating hyperandrogenic symptoms, inducing ovulation and preventing cardiometabolic complications.

Progesterone treatment inhibits and dihydrotestosterone (DHT) treatment potentiates voltage-gated calcium currents in gonadotropin-releasing hormone (GnRH) neurons

GnRH neurons are central regulators of fertility, and their activity is modulated by steroid feedback. In normal females, GnRH secretion is regulated by estradiol and progesterone (P). Excess androgens present in hyperandrogenemic fertility disorders may disrupt communication of negative feedback signals from P and/or independently stimulate GnRH release. Voltage-gated calcium channels (VGCCs) are important in regulating excitability and hormone release. Estradiol alters VGCCs in a time-of-day-dependent manner. To further elucidate ovarian steroid modulation of GnRH neuron VGCCs, we studied the effects of dihydrotestosterone (DHT) and P. Adult mice were ovariectomized (OVX) or OVX and treated with implants containing DHT (OVXD), estradiol (OVXE), estradiol and DHT (OVXED), estradiol and P (OVXEP), or estradiol, DHT, and P (OVXEDP). Macroscopic calcium current (I(Ca)) was recorded in the morning or afternoon 8-12 d after surgery using whole-cell voltage-clamp. I(Ca) was increased in afternoon vs. morning in GnRH neurons from OVXE mice but this increase was abolished in cells from OVXEP mice. I(Ca) in cells from OVXD mice was increased regardless of time of day; there was no additional effect in OVXED mice. P reduced N-type and DHT potentiated N- and R-type VGCCs; P blocked the DHT potentiation of N-type-mediated current. These data suggest P and DHT have opposing actions on VGCCs in GnRH neurons, but in the presence of both steroids, P dominates. VGCCs are targets of ovarian steroid feedback modulation of GnRH neuron activity and, more specifically, a potential mechanism whereby androgens could activate GnRH neuronal function.

Rescue of obesity-induced infertility in female mice due to a pituitary-specific knockout of the insulin receptor

Obesity is associated with insulin resistance in metabolic tissues such as adipose, liver, and muscle, but it is unclear whether nonclassical target tissues, such as those of the reproductive axis, are also insulin resistant. To determine if the reproductive axis maintains insulin sensitivity in obesity in vivo, murine models of diet-induced obesity (DIO) with and without intact insulin signaling in pituitary gonadotrophs were created. Diet-induced obese wild-type female mice (WT DIO) were infertile and experienced a robust increase in luteinizing hormone (LH) after gonadotropin-releasing hormone (GnRH) or insulin stimulation. By contrast, both lean and obese mice with a pituitary-specific knockout of the insulin receptor (PitIRKO) exhibited reproductive competency, indicating that insulin signaling in the pituitary is required for the reproductive impairment seen in DIO and that the gonadotroph maintains insulin sensitivity in a setting of peripheral insulin resistance.

GnRH signaling, the gonadotrope and endocrine control of fertility

Mammalian reproductive cycles are controlled by an intricate interplay between the hypothalamus, pituitary and gonads. Central to the function of this axis is the ability of the pituitary gonadotrope to appropriately respond to stimulation by gonadotropin-releasing hormone (GnRH). This review focuses on the role of cell signaling and in particular, mitogen-activated protein kinase (MAPK) activities regulated by GnRH that are necessary for normal fertility. Recently, new mouse models making use of conditional gene deletion have shed new light on the relationships between GnRH signaling and fertility in both male and female mice. Within the reproductive axis, GnRH signaling is initiated through discrete membrane compartments in which the receptor resides leading to the activation of the extracellular signal-regulated kinases (ERKs 1/2). As defined by gonadotrope-derived cellular models, the ERKs appear to play a central role in the regulation of a cohort of immediate early genes that regulate the expression of late genes that, in part, define the differentiated character of the gonadotrope. Recent data would suggest that in vivo, conditional, pituitary-specific disruption of ERK signaling by GnRH leads to a gender-specific perturbation of fertility. Double ERK knockout in the anterior pituitary leads to female infertility due to LH biosynthesis deficiency and a failure in ovulation. In contrast, male mice are modestly LH deficient; however, this does not have an appreciable impact on fertility.

Hormones in synergy: regulation of the pituitary gonadotropin genes

The precise interplay of hormonal influences that governs gonadotropin hormone production by the pituitary includes endocrine, paracrine and autocrine actions of hypothalamic gonadotropin-releasing hormone (GnRH), activin and steroids. However, most studies of hormonal regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the pituitary gonadotrope have been limited to analyses of the isolated actions of individual hormones. LHbeta and FSHbeta subunits have distinct patterns of expression during the menstrual/estrous cycle as a result of the integration of activin, GnRH, and steroid hormone action. In this review, we focus on studies that delineate the interplay among these hormones in the regulation of LHbeta and FSHbeta gene expression in gonadotrope cells and discuss how signaling cross-talk contributes to differential expression. We also discuss how recent technological advances will help identify additional factors involved in the differential hormonal regulation of LH and FSH.

The biology of gonadotroph regulation

PURPOSE OF REVIEW

To discuss recent progress in our understanding of pituitary gonadotroph development and gonadotropin gene regulation, with an emphasis on differential luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion and subunit synthesis, and the implications this may have on female reproductive health.

RECENT FINDINGS

In the mature gonadotroph, there is an emerging concept that differential synthesis of gonadotropin beta-subunit genes, essential for cyclic reproductive function, is associated with modification of activation and/or stability of important regulatory proteins and transcription factors. Recent studies suggest that cellular events, which affect histone modification, play an essential role in both gonadotroph development and the ontogeny of gonadotropin subunit gene expression. Such dynamic events are under the orchestration of the hypothalamic neuropeptide gonadotropin-releasing hormone (GnRH), potentially through the ability of GnRH to activate several distinct signaling cascades within the gonadotroph.

SUMMARY

Greater insight into the cellular events that are key to gonadotroph physiology will contribute to our understanding of abnormal gonadotropin secretion in disorders such as hypothalamic amenorrhea and polycystic ovarian syndrome (PCOS), and provide a context for the design of novel therapeutic approaches.

Excessive ovarian production of nerve growth factor facilitates development of cystic ovarian morphology in mice and is a feature of polycystic ovarian syndrome in humans

Although ovarian nerve growth factor (NGF) facilitates follicular development and ovulation, an excess of the neurotrophin in the rodent ovary reduces ovulatory capacity and causes development of precystic follicles. Here we show that ovarian NGF production is enhanced in patients with polycystic ovarian syndrome (PCOS) and that transgenically driven overproduction of NGF targeted to the ovary results in cystic morphology, when accompanied by elevated LH levels. NGF levels are increased in the follicular fluid from PCOS ovaries and in the culture medium of granulosa cells from PCOS patients, as compared with non-PCOS patients. Ovaries from transgenic mice carrying the NGF gene targeted to thecal-interstitial cells by the 17alpha-hydroxylase gene promoter produce more NGF than wild-type (WT) ovaries and are hyperinnervated by sympathetic nerves. Antral follicle growth is arrested resulting in accumulation of intermediate size follicles, many of which are apoptotic. Peripubertal transgenic mice respond to a gonadotropin challenge with a greater increase in plasma 17-hydroxyprogesterone, estradiol, and testosterone levels than WT controls. Transgenic mice also exhibit a reduced ovulatory response, delayed puberty, and reduced fertility, as assessed by a prolonged interval between litters, and a reduced number of pups per litter. Sustained, but mild, elevation of plasma LH levels results in a heightened incidence of ovarian follicular cysts in transgenic mice as compared with WT controls. These results suggest that overproduction of ovarian NGF is a component of polycystic ovarian morphology in both humans and rodents and that a persistent elevation in plasma LH levels is required for the morphological abnormalities to appear.

The reproductive phenotype in polycystic ovary syndrome

The symptoms of women with polycystic ovary syndrome (PCOS) include hirsutism and irregular menstrual bleeding due to ovarian androgen excess and chronic anovulation. Typically, these features emerge late in puberty or shortly thereafter. The proposed mechanism(s) responsible for increased ovarian androgen production include heightened theca cell responsiveness to gonadotropin stimulation, increased pituitary secretion of luteinizing hormone, and hyperinsulinemia. The cause of ovulatory dysfunction is not well understood, but is linked to abnormal follicle growth and development within the ovary. As a result, infertility is common among women with PCOS and, in many instances, is the initial presenting complaint. Insulin resistance and obesity are frequently associated with PCOS and probably contribute to the severity of symptoms. The polycystic ovary that accompanies the syndrome has recently been defined as having 12 or more follicles per ovary or an ovarian volume greater than 10 ml as determined by ultrasonography. In addition, there is an increased number of growing follicles in the polycystic ovary. Despite this distinctive appearance, the cause and development of the polycystic ovary are completely unknown.

Inverse relationship between luteinizing hormone and body mass index in polycystic ovarian syndrome: investigation of hypothalamic and pituitary contributions

CONTEXT

Patients with polycystic ovarian syndrome (PCOS) have increased LH relative to FSH, but LH is modified by body mass index (BMI).

OBJECTIVE

The objective of the study was to determine whether the impact of BMI on neuroendocrine dysregulation in PCOS is mediated at the hypothalamic or pituitary level. PARTICIPANTS/INTERVENTIONS/SETTING: Twenty-four women with PCOS across a spectrum of BMIs underwent frequent blood sampling, iv administration of GnRH (75 ng/kg), and sc administration of the NAL-GLU GnRH antagonist (5 microg/kg) in the General Clinical Research Center at an academic hospital.

MAIN OUTCOME MEASURES

LH pulse frequency and LH response to submaximal GnRH receptor blockade were used as measures of hypothalamic function; LH response to GnRH was used as a measure of pituitary responsiveness.

RESULTS

BMI was negatively correlated with mean LH, LH/FSH, and LH pulse amplitude. There was no effect of BMI on LH pulse frequency. Percent inhibition of LH was decreased in PCOS, compared with normal women (53.9 +/- 1.5 vs. 63.1 +/- 4.1, respectively; P < 0.01), suggesting an increase in the amount of endogenous GnRH, but was not influenced by BMI. Pituitary responsiveness to GnRH was inversely correlated with BMI (peak LH, R = -0.475, P < 0.02; and LH area under the curve R = -0.412, P < 0.02).

CONCLUSIONS

LH pulse frequency and quantity of GnRH are increased in PCOS, but there is no influence of BMI on either marker of hypothalamic function. The pituitary response to a weight-based dose of GnRH is inversely related to BMI in PCOS. These studies suggest that the effect of BMI on LH is mediated at a pituitary and not a hypothalamic level in PCOS.

Fetal programming: excess prenatal testosterone reduces postnatal luteinizing hormone, but not follicle-stimulating hormone responsiveness, to estradiol negative feedback in the female

Exposure of female sheep fetuses to excess testosterone (T) during early to midgestation produces postnatal hypergonadotropism manifest as a selective increase in LH. This hypergonadotropism may result from reduced sensitivity to estradiol (E2) negative feedback and/or increased pituitary sensitivity to GnRH. We tested the hypothesis that excess T before birth reduces responsiveness of LH and FSH to E2 negative feedback after birth. Pregnant ewes were treated with T propionate (100 mg/kg in cotton seed oil) or vehicle twice weekly from d 30-90 gestation. Responsiveness to E2 negative feedback was assessed at 12 and 24 wk of age in the ovary-intact female offspring. Our experimental strategy was first to arrest follicular growth and reduce endogenous E2 by administering the GnRH antagonist (GnRH-A), Nal-Glu (50 microg/kg sc every 12 h for 72 h), and then provide a fixed amount of exogenous E2 via an implant. Blood samples were obtained every 20 min at 12 wk and every 10 min at 24 wk before treatment, during and after GnRH-A treatment both before and after E2 implant. GnRH-A ablated LH pulsatility, reduced FSH by approximately 25%, and E2 production diminished to near detection limit of assay at both ages in both groups. Prenatal T treatment produced a precocious and selective reduction in responsiveness of LH but not FSH to E2 negative feedback, which was manifest mainly at the level of LH/GnRH pulse frequency. Collectively, these findings support the hypothesis that prenatal exposure to excess T decreases postnatal responsiveness to E2 inhibitory feedback of LH/GnRH secretion to contribute to the development of hypergonadotropism.

Prenatal androgens alter GABAergic drive to gonadotropin-releasing hormone neurons: implications for a common fertility disorder

Polycystic ovary syndrome, a fertility disorder affecting approximately 7% of women, is characterized by elevated androgens, disrupted reproductive cycles, and high luteinizing hormone, the latter reflecting increased gonadotropin-releasing hormone (GnRH) release. In animal models, a similar reproductive endocrine phenotype occurs after prenatal androgen exposure. To study the effects of in utero androgen exposure directly on GnRH neurons, the central regulators of fertility, we prenatally androgenized (PNA) transgenic mice that express GFP in these cells. Pregnant females were injected with dihydrotestosterone, and their female offspring were studied as adults. PNA mice had irregular estrous cycles and elevated testosterone and luteinizing hormone levels, suggesting altered hypothalamo-pituitary-gonadal axis function. GnRH neurons receive a major input from gamma-aminobutyric acid (GABA)ergic neurons, and GABA type A receptor activation may play a role in their regulation by steroids. We tested whether PNA alters GABAergic drive to GnRH neurons by comparing frequency and size of GABAergic postsynaptic currents in GnRH neurons from PNA and control females. Both postsynaptic current frequency and size were increased in PNA mice; these effects were reversed by in vivo treatment with the androgen receptor antagonist flutamide, suggesting that androgens mediated these effects. Changes in postsynaptic current frequency and size were action potential-independent, suggesting the possibility that PNA increased connectivity between GABAergic and GnRH neurons. The ability of prenatal steroid exposure to initiate changes that alter functional inputs to GnRH neurons in adults has important implications for understanding the regulation of normal reproduction as well as the hypothalamic abnormalities of fertility disorders.

Relationship of GnRH-stimulated LH release to episodic LH secretion and baseline endocrine-metabolic measures in women with polycystic ovary syndrome

BACKGROUND AND OBJECTIVE

In polycystic ovary syndrome (PCOS) inappropriate gonadotrophin secretion is characterized by increased pulse frequency and amplitude, elevated 24-h mean serum concentrations, and greater responses to GnRH. While the mechanism(s) responsible for this increased release of LH are not well understood, enhanced LH secretion has been attributed to increased pituitary sensitivity to GnRH and feedback influences from circulating steroid hormones. To address these considerations, we conducted a study to examine the relationships between GnRH-stimulated LH responses, episodic gonadotrophin secretion, and baseline measurements of endocrine-metabolic function in PCOS.

PATIENTS

Serum LH responses to sequential multidose GnRH administration and pulsatile gonadotrophin secretion were examined in 13 PCOS and 13 normal women.

MEASUREMENTS

Serum LH, steroid hormone, insulin and glucose levels were determined in blood samples obtained during assessment of episodic gonadotrophin secretion and LH responses to GnRH stimulation.

DESIGN

Each subject was studied on two consecutive days. On study day 1 each subject underwent frequent blood sampling every 10 min for 12 h. On study day 2 each received sequential doses of GnRH, 2 microg, 10 microg and 20 microg, administered intravenously at 4-h intervals over a continuous 12-h period.

RESULTS

Serum LH responses following GnRH were markedly greater in PCOS compared to normal women, as expected. In individual PCOS, peak LH responses to GnRH were significantly correlated with corresponding basal LH and LH pulse amplitude, but not LH pulse frequency. In the PCOS group, LH responses were positively correlated with serum oestradiol (E2) and inversely related to body mass index (BMI). Between-group differences in LH responsiveness disappeared when controlling for serum testosterone (T) levels.

CONCLUSIONS

These results indicate that the absolute LH increment following GnRH is largely dependent on baseline LH levels and may account for the well-documented difference in LH responsiveness between PCOS and normal women. That neither LH responses to GnRH nor LH pulse amplitude were correlated to LH pulse frequency suggests involvement of other factors along with GnRH to account for increased LH secretion in PCOS. In addition to E2 and BMI, serum testosterone appears to be, at least in part, responsible for differences in LH secretion and release between PCOS and normal women.

Insulin-lowering agents in the management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a medical condition that has brought multiple specialists together. Gynecologists, endocrinologists, cardiologists, pediatricians, and dermatologists are all concerned with PCOS patients and share research data and design clinical trials to learn more about the syndrome. Insulin resistance is a common feature of PCOS and is more marked in obese women, suggesting that PCOS and obesity have a synergistic effect on the magnitude of the insulin disorder. Hyperinsulinemia associated with insulin resistance has been causally linked to all features of the syndrome, such as hyperandrogenism, reproductive disorders, acne, hirsutism, and metabolic disturbances. Women with PCOS should be evaluated for cardiovascular risk factors, such as lipid profile and blood pressure. Modification of diet and lifestyle should be suggested to those who are obese. Several insulin-lowering agents have been tested in the management of PCOS. In particular, metformin is the only drug currently in widespread clinical use for treatment of PCOS. In a high percentage of patients, treatment with metformin is followed by regularization of menstrual cycle, reduction in hyperandrogenism and in cardiovascular risk factors, and improvement in response to therapies for induction of ovulation.

GH release after GHRH plus arginine administration in obese and overweight women with polycystic ovary syndrome

Few and unclear data are available in the literature about the relationship between impairment of GH/IGF-I axis and polycystic ovary syndrome (PCOS). This study was aimed to evaluate the basal GH and IGF- levels, and GH release after challenge test in obese and overweight women with PCOS. Thirty patients with PCOS and other 30 healthy women matched for age, body mass index (BMI) and waist-hip ratio (WHR) were studied. Serum follicle-stimulating hormone (FSH), LH, PRL, E2, P, 17OH-progesterone (17OH-P), total T, delta4, DHEA-S, SHBG, GH and IGF-I levels were evaluated in each subject. A GHRH plus arginine challenge test was performed in all subjects. After provocative test, in PCOS and control women the GH levels were significantly (p<0.05) higher in comparison to basal values from 30 min to 120 min. At the same times, a significant (p<0.05) difference was observed between women with PCOS in comparison to healthy women. The mean peak value of GH resulted significantly (p<0.05) lower in PCOS women in comparison to healthy women. The total GH response (area under curve, AUC) to GHRH plus arginine test resulted significantly (p<0.05) lower in PCOS than in healthy women. These findings were statistically significant (p<0.05) also considering the distinction in obese and overweight women. The AUC for GH secretion was significantly lower (p<0.05) in obese in comparison to overweight subjects in the control group, whereas no significant difference was detected between obese and overweight women in the PCOS group. In conclusion, in PCOS women there is a BMI-independent alteration of the GH levels. Further investigations will be necessary to establish the real cause of these data.

Definition of polycystic ovary syndrome

This article aims to answer two questions in defining polycystic ovary syndrome (PCOS): what is PCOS and how should the syndrome be recognized in clinical practice? Whether PCOS is a primary or a secondary ovarian disease remains controversial. It has been suggested for many years that the main pathophysiological factor in PCOS is dysregulation of the relationship between the hypothalamus, the pituitary and the ovary. However, PCOS also involves intraovarian morphological and functional abnormalities. With respect to clinical practice, many reports have questioned the sensitivity as well as the specificity of a high LH concentration. Similarly, the biological hyperandrogenism of PCOS cannot define the syndrome. GnRH agonist or hCG tests are not convenient for the diagnosis of PCOS in practice. Stromal hyperplasia is considered to be indicative of PCOS but it is highly dependent on the settings of the ultrasound machine, thus use of the total ovarian area, the upper normal limit of which is 5.5 cm(2), is recommended. The need for diagnostic markers of PCOS depends on the clinical presentation. In the full-blown syndrome (classic PCOS), the clinical symptoms provide the most powerful indication and the association of the three components (hyperandrogenism, anovulatory dysfunction and metabolic abnormalities) has a strong diagnostic potency. In non-classic PCOS, a cost-effective and safe work-up should be applied, which includes ultrasonography and hormonal assays (basal serum concentrations of testosterone, sex hormone binding globulin, 17-hydroxyprogesterone, LH, FSH and prolactin). Asymptomatic PCOS may be discovered incidentally during ultrasonography, and it is important to take this finding into account when designing an ovulation induction protocol. In most cases of PCOS, the diagnosis may remain presumptive providing other diagnoses have been ruled out and the follow-up does not disclose any atypical development of the condition.

Extremely high levels of estradiol and testosterone in a case of polycystic ovarian syndrome. Hormone and clinical similarities with the phenotype of the alpha estrogen receptor null mice

A 19-year-old nulliparous hirsute woman was evaluated for the very high serum levels of testosterone (T) and estradiol (E2) measured in an outside laboratory. Menarche had occurred at 11 years and was followed by regular menses. We confirmed the high levels of T (9-16 ng/ml, nv 0.2-0.8) and E2 (>1,000 pg/ml, nv 30-120). LH and FSH were consistently high (73-118 mU/l and 18-29 mU/l, respectively; LH/FSH ratio=4.1-4.7) and responsive to iv GnRH (LH baseline=118 mU/I, 30 min=290; FSH baseline=25 mU/l, 30 min=46). The unstimulated values contrasted with those (LH=12, FSH=8 mU/I) measured in the outside laboratory, suggesting antigenically anomalous gonadotropins. 17-OH-progesterone was normal (0.5 ng/ml). After 1 mg dexamethasone, serum cortisol was normally suppressed (24-->0.4 microg/dl), T declined minimally (9-->8.6 ng/ml) and E2 remained high (>1,000 pg/ml). An exploratory laparotomy was performed, and two enlarged ovaries with multiple cysts as in a typical polycystic ovarian syndrome (PCOS) were seen. Before the wedge resection of the ovaries, hormones were assayed in the ovary veins (right ovary: T=30 ng/ml, Pg=17 ng/ml, E2=>5,000 pg/ml; left: T=14 ng/ml, Pg=14 ng/ml, E2=>5,000 pg/ml). Histologically, the follicle cysts showed luteinization of the theca interna; there was no evidence for ovary tumor in either ovary. After 21 days of 35 microg ethynyl-E2+2 mg cyproterone acetate (CA), E2=3,000 pg/ml, T=1.4 ng/ml, LH=10.5 mU/l and FSH=4.1 mU/I. After three cycles of the said therapy (but with 50 mg CA in the first 10 days of each cycle), E2 was 1,600 pg/ml, T 1.7 ng/ml, LH 7.1 and FSH 4.6 mU/I. Based on similarities with the phenotype of the alpha estrogen receptor knockout female mice (alphaERKO), one possible explanation for the puzzling clinical and biochemical picture of our patient is resistance of (alphaER to estrogens. This is the first case of PCOS with extremely high E2 and T. Thus, the differential diagnosis of high levels of E2 +/- T should include PCOS.