Intrauterine Reprogramming of the Polycystic Ovary Syndrome: Evidence from a Pilot Study of Cord Blood Global Methylation Analysis

Polycystic ovary syndrome

Despite affecting ~11-13% of women globally, polycystic ovary syndrome (PCOS) is a substantially understudied condition. PCOS, possibly extending to men's health, imposes a considerable health and economic burden worldwide. Diagnosis in adults follows the International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome, requiring two out of three criteria - clinical or biochemical hyperandrogenism, ovulatory dysfunction, and/or specific ovarian morphological characteristics or elevated anti-Müllerian hormone. However, diagnosing adolescents omits ovarian morphology and anti-Müllerian hormone considerations. PCOS, marked by insulin resistance and hyperandrogenism, strongly contributes to early-onset type 2 diabetes, with increased odds for cardiovascular diseases. Reproduction-related implications include irregular menstrual cycles, anovulatory infertility, heightened risks of pregnancy complications and endometrial cancer. Beyond physiological manifestations, PCOS is associated with anxiety, depression, eating disorders, psychosexual dysfunction and negative body image, collectively contributing to diminished health-related quality of life in patients. Despite its high prevalence persisting into menopause, diagnosing PCOS often involves extended timelines and multiple health-care visits. Treatment remains ad hoc owing to limited understanding of underlying mechanisms, highlighting the need for research delineating the aetiology and pathophysiology of the syndrome. Identifying factors contributing to PCOS will pave the way for personalized medicine approaches. Additionally, exploring novel biomarkers, refining diagnostic criteria and advancing treatment modalities will be crucial in enhancing the precision and efficacy of interventions that will positively impact the lives of patients.

DNA methylation associated with polycystic ovary syndrome: a systematic review

PURPOSE

Polycystic ovary syndrome (PCOS) is an endocrine metabolic disease that affects women of reproductive age and is one of the main causes of anovulatory infertility. However, the cause of PCOS is yet fully understood, and genetic factors play an important role in its etiology. In this study, we reviewed the main genes involved in the etiology of PCOS and the influence of DNA methylation, aiming to answer the study´s guiding question: 'What is the influence of DNA methylation on the main genes involved in PCOS?'.

METHODS

We used the MEDLINE database, and inclusion criteria (primary and original articles, written in English, found through our entry terms) and exclusion criteria (literature reviews and articles that used animals to perform the experiments and that focused in other epigenetics mechanism without being DNA methylation) were applied.

RESULTS

Twenty-three scientific articles, from a total of 43 articles read in full, were chosen for this study. Eighteen studies confirmed DNA methylation associated with PCOS.

CONCLUSION

The most relevant genes related to PCOS were INSR, LHCGR, and RAB5B, which may be epigenetically altered in DNA, with the first two genes hypomethylated and the last hypermethylated. The epigenetic changes presented in the genes related to PCOS or their promoters were only at the CpG sites.

A policy brief on improving the lifestyle of women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) in women is a significant public health issue. We searched the relevant databases using the sensitive keywords to receive the available evidence for successful lifestyle interventions among PCOS women. The systematic reviews related to PCOS were evaluated for an effective lifestyle intervention that was identified. The lifestyle interventions include three components: weight management, physical exercise, and behavioral coaching or combined interventions for developing exercise and modifying diet. Evidence shows that the impact of starting lifestyle intervention as the first-line management to improve obstetric and reproductive outcomes is high. There is evidence that proves health coaching can improve health behaviors and lifestyle. Thus, it is recommended to improve the lifestyle of women with PCOS.

Examination of newborn DNA methylation among women with polycystic ovary syndrome/hirsutism

Research suggests that polycystic ovary syndrome (PCOS) traits (e.g., hyperandrogenism) may create a suboptimal intrauterine environment and induce epigenetic modifications. Therefore, we assessed the associations of PCOS traits with neonatal DNA methylation (DNAm) using two independent cohorts. DNAm was measured in both cohorts using the Infinium MethylationEPIC array. Multivariable robust linear regression was used to determine associations of maternal PCOS exposure or preconception testosterone with methylation β-values at each CpG probe and corrected for multiple testing by false-discovery rate (FDR). In the birth cohort, 12% (102/849) had a PCOS diagnosis (8.1% PCOS without hirsutism; 3.9% PCOS with hirsutism). Infants exposed to maternal PCOS with hirsutism compared to no PCOS had differential DNAm at cg02372539 [β(SE): -0.080 (0.010); FDR p = 0.009], cg08471713 [β(SE):0.077 (0.014); FDR p = 0.016] and cg17897916 [β(SE):0.050 (0.009); FDR p = 0.009] with adjustment for maternal characteristics including pre-pregnancy BMI. PCOS with hirsutism was also associated with 8 differentially methylated regions (DMRs). PCOS without hirsutism was not associated with individual CpGs. In an independent preconception cohort, total testosterone concentrations were associated with 3 DMRs but not with individual CpGs, though the top quartile of testosterone compared to the lowest was marginally associated with increased DNAm at cg21472377 near an uncharacterized locus (FDR p = 0.09). Examination of these probes and DMRs indicate they may be under foetal genetic control. Overall, we found several associations among newborns exposed to PCOS, specifically when hirsutism was reported, and among newborns of women with relatively higher testosterone around conception.

The Influences of Perinatal Androgenic Exposure on Cardiovascular and Metabolic Disease of Offspring of PCOS

Hyperandrogenism is an endocrine disorder affecting a large population of reproductive-aged women, thus proportionally high number of fetuses are subjected to prenatal androgenic exposure (PNA). The short-term stimulations at critical ontogenetic stages can wield lasting influences on the health. The most commonly diagnosed conditions in reproductive age women is polycystic ovary syndrome (PCOS). PNA may affect the growth and development of many systems in the whole body and disrupts the normal metabolic trajectory in the offspring of PCOS, contributing to the prevalence of cardiovascular and metabolic diseases (CVMD), including myocardial hypertrophy, hypertension, hyperinsulinemia, insulin resistance, hyperglycemia, obesity, and dyslipidemia, which are the leading causes of hospitalizations in young PCOS offspring. In this review, we focus on the effects of prenatal androgenic exposure on the cardiovascular and metabolic diseases in offspring, discuss the possible pathogenesis respectively, and summarize potential management strategies to improve metabolic health of PCOS offspring. It is expected that the incidence of CVMD and the medical burden will be reduced in the future.

Mitochondrial epigenetic modifications and nuclear-mitochondrial communication: A new dimension towards understanding and attenuating the pathogenesis in women with PCOS

Mitochondrial DNA (mtDNA) epigenetic modifications have recently gained attention in a plethora of complex diseases, including polycystic ovary syndrome (PCOS), a common cause of infertility in women of reproductive age. Herein we discussed mtDNA epigenetic modifications and their impact on nuclear-mitochondrial interactions in general and the latest advances indicating the role of mtDNA methylation in the pathophysiology of PCOS. We highlighted epigenetic changes in nuclear-related mitochondrial genes, including nuclear transcription factors that regulate mitochondrial function and may be involved in the development of PCOS or its related traits. Additionally, therapies targeting mitochondrial epigenetics, including time-restricted eating (TRE), which has been shown to have beneficial effects by improving mitochondrial function and may be mediated by epigenetic modifications, have also been discussed. As PCOS has become a major metabolic disorder and a risk factor for obesity, cardiometabolic disorders, and diabetes, lifestyle/behavior intervention using TRE that reinforces feeding-fasting rhythms without reducing caloric intake may be a promising therapeutic strategy for attenuating the pathogenesis. Furthermore, future perspectives in the area of mitochondrial epigenetics are described.

Polycystic Ovary Syndrome: Challenges and Possible Solutions

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. This syndrome not only impairs female fertility but also increases the risk of obesity, diabetes, dyslipidemia, cardiovascular diseases, psychological diseases, and other health problems. Additionality, because of the high clinical heterogeneity, the current pathogenesis of PCOS is still unclear. There is still a large gap in precise diagnosis and individualized treatment. We summarize the present findings concerning the genetics, epigenetics, gut microbiota, corticolimbic brain responses, and metabolomics of the PCOS pathogenesis mechanism, highlight the remaining challenges in PCOS phenotyping and potential treatment approaches, and explain the vicious circle of intergenerational transmission of PCOS, which might provide more thoughts for better PCOS management in the future.

Role of Hormones During Gestation and Early Development: Pathways Involved in Developmental Programming

Accumulating evidence suggests that an altered maternal milieu and environmental insults during the intrauterine and perinatal periods of life affect the developing organism, leading to detrimental long-term outcomes and often to adult pathologies through programming effects. Hormones, together with growth factors, play critical roles in the regulation of maternal-fetal and maternal-neonate interfaces, and alterations in any of them may lead to programming effects on the developing organism. In this chapter, we will review the role of sex steroids, thyroid hormones, and insulin-like growth factors, as crucial factors involved in physiological processes during pregnancy and lactation, and their role in developmental programming effects during fetal and early neonatal life. Also, we will consider epidemiological evidence and data from animal models of altered maternal hormonal environments and focus on the role of different tissues in the establishment of maternal and fetus/infant interaction. Finally, we will identify unresolved questions and discuss potential future research directions.

Impaired Carbohydrate Metabolism and Excess of Lipid Accumulation in Offspring of Hyperandrogenic Mice

Polycystic ovary syndrome (PCOS) is an endocrine-metabolic disorder of unknown etiology. Hyperandrogenism (HA) is the main diagnostic criteria for PCOS, in addition to being a risk factor for developing several disorders throughout the patient's life, including pregnancy. However, the impact on offspring is little known. Therefore, the aim of this work was to evaluate the effect of maternal HA on glucose metabolism and hepatic lipid accumulation in adult offspring. We used Balb/c mice treated with dehydroepiandrosterone (DHEA) for 20 consecutive days. The ovary of DHEA-treated mice showed hemorrhagic bodies, an increased number of atretic follicles, and greater expression of genes related to meiotic cell cycle and DNA repair. The DHEA offspring (O-DHEA) had low birth weight, and some pups showed malformations. However, O-DHEA individuals gained weight rapidly, and the differences between them and the control group became significantly greater in adulthood. Moreover, O-DHEA presented higher serum glucose after a 6 h fast and a larger area under glucose, insulin, and pyruvate tolerance test curves. Oil Red O staining showed a more significant accumulation of fat in the liver but no changes in serum cholesterol and triacylglycerol levels. In summary, our results show that HA, induced by DHEA, affects gene expression in oocyte, which in turn generates defects in embryonic development, insulin resistance, and alteration in hepatic gluconeogenesis and lipid metabolism in O-DHEA, thereby increasing the risk of developing metabolic diseases.

Deconstructing a Syndrome: Genomic Insights Into PCOS Causal Mechanisms and Classification

Polycystic ovary syndrome (PCOS) is among the most common disorders in women of reproductive age, affecting up to 15% worldwide, depending on the diagnostic criteria. PCOS is characterized by a constellation of interrelated reproductive abnormalities, including disordered gonadotropin secretion, increased androgen production, chronic anovulation, and polycystic ovarian morphology. It is frequently associated with insulin resistance and obesity. These reproductive and metabolic derangements cause major morbidities across the lifespan, including anovulatory infertility and type 2 diabetes (T2D). Despite decades of investigative effort, the etiology of PCOS remains unknown. Familial clustering of PCOS cases has indicated a genetic contribution to PCOS. There are rare Mendelian forms of PCOS associated with extreme phenotypes, but PCOS typically follows a non-Mendelian pattern of inheritance consistent with a complex genetic architecture, analogous to T2D and obesity, that reflects the interaction of susceptibility genes and environmental factors. Genomic studies of PCOS have provided important insights into disease pathways and have indicated that current diagnostic criteria do not capture underlying differences in biology associated with different forms of PCOS. We provide a state-of-the-science review of genetic analyses of PCOS, including an overview of genomic methodologies aimed at a general audience of non-geneticists and clinicians. Applications in PCOS will be discussed, including strengths and limitations of each study. The contributions of environmental factors, including developmental origins, will be reviewed. Insights into the pathogenesis and genetic architecture of PCOS will be summarized. Future directions for PCOS genetic studies will be outlined.

Modulation of the Inflammatory Response in Polycystic Ovary Syndrome (PCOS)-Searching for Epigenetic Factors

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. Despite its incidence, the syndrome is poorly understood and remains underdiagnosed, and female patients are diagnosed with a delay. The heterogenous nature of this complex disorder results from the combined occurrence of genetic, environmental, endocrine, and behavioral factors. Primary clinical manifestations of PCOS are derived from the excess of androgens (anovulation, polycystic ovary morphology, lack of or scanty, irregular menstrual periods, acne and hirsutism), whereas the secondary manifestations include multiple metabolic, cardiovascular, and psychological disorders. Dietary and lifestyle factors play important roles in the development and course of PCOS, which suggests strong epigenetic and environmental influences. Many studies have shown a strong association between PCOS and chronic, low-grade inflammation both in the ovarian tissue and throughout the body. In the vast majority of PCOS patients, elevated values of inflammatory markers or their gene markers have been reported. Development of the vicious cycle of the chronic inflammatory state in PCOS is additionally stimulated by hyperinsulinemia and obesity. Changes in DNA methylation, histone acetylation and noncoding RNA levels are presented in this review in the context of oxidative stress, reactive oxygen species, and inflammatory signaling in PCOS. Epigenetic modulation of androgenic activity in response to inflammatory signaling is also discussed.

Update on Animal Models of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex disease affecting up to 15% of women of reproductive age. Women with PCOS suffer from reproductive dysfunctions with excessive androgen secretion and irregular ovulation, leading to reduced fertility and pregnancy complications. The syndrome is associated with a wide range of comorbidities including type 2 diabetes, obesity, and psychiatric disorders. Despite the high prevalence of PCOS, its etiology remains unclear. To understand the pathophysiology of PCOS, how it is inherited, and how to predict PCOS, and prevent and treat women with the syndrome, animal models provide an important approach to answering these fundamental questions. This minireview summarizes recent investigative efforts on PCOS-like rodent models aiming to define underlying mechanisms of the disease and provide guidance in model selection. The focus is on new genetic rodent models, on a naturally occurring rodent model, and provides an update on prenatal and peripubertal exposure models.

Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects 5-18% of women, and is a reproductive, metabolic, and psychological condition with impacts across the lifespan. The cause is complex, and includes genetic and epigenetic susceptibility, hypothalamic and ovarian dysfunction, excess androgen exposure, insulin resistance, and adiposity-related mechanisms. Diagnosis is recommended based on the 2003 Rotterdam criteria and confirmed with two of three criteria: hyperandrogenism (clinical or biochemical), irregular cycles, and polycystic ovary morphology. In adolescents, both the criteria of hyperandrogenism and irregular cycles are needed, and ovarian morphology is not included due to poor specificity. The diagnostic criteria generates four phenotypes, and clinical features are heterogeneous, with manifestations typically arising in childhood and then evolving across adolescent and adult life. Treatment involves a combination of lifestyle alterations and medical management. Lifestyle optimisation includes a healthy balanced diet and regular exercise to prevent excess weight gain, limit PCOS complications and target weight reduction when needed. Medical management options include metformin to improve insulin resistance and metabolic features, combined oral contraceptive pill for menstrual cycle regulation and hyperandrogenism, and if needed, anti-androgens for refractory hyperandrogenism. In this Review, we provide an update on the pathophysiology, diagnosis, and clinical features of PCOS, and discuss the needs and priorities of those with PCOS, including lifestyle, and medical and infertility treatment. Further we discuss the status of international evidence-based guidelines (EBG) and translation, to support patient self management, healthcare provision, and to set research priorities.

Role of genomic DNA methylation in PCOS pathogenesis: a systematic review and meta-analysis involving case controlled clinical studies

PCOS is often associated with aberrant DNA methylation. Despite the advances in diagnostics and treatment of PCOS, the pathophysiological mechanism remain unknown. Several genes are epigenetically dysregulated in PCOS and associated with pathological consequences of PCOS and metabolic comorbidities, however the methylation status of specific genes and to what extent the genes are deregulated in terms of methylation pattern are unknown. This review aimed to analyse the existing data for specific genes and find conclusive evidence of their involvement in PCOS and associated risks. A comprehensive literature search was conducted in five electronic databases. The case-controlled clinical studies using both PCOS and healthy women and evaluating the methylation pattern without any treatment or intervention were included in the study. A random-effect model was used to extract the data for meta-analysis, and outcomes were expressed as standardized mean difference with a 95% CI. From 541 screened records, 41 studies were included in the review and 21 of them were used for meta-analysis of 20 genes. Meta-analysis revealed a significant global DNA hypomethylation in different tissues and peripheral blood of patients with PCOS compared to healthy controls. Specific gene methylation assessment revealed that genes associated with several functions were significantly hypomethylated and hypermethylated in patients with PCOS. This review provides conclusive evidence of epigenetic deregulation of specific genes in PCOS. These genes can potentially be used to develop diagnostic biomarkers or as targets for personalised therapy.

Explore the potential molecular mechanism of polycystic ovarian syndrome by protein-protein interaction network analysis

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders prevailing in reproductive age women, present in 3-15% population of women worldwide. Although there are many studies on PCOS, its underlying mechanism remains to be determined. The present study was to construct protein-protein interaction networks based on the potential disease-causing genes for PCOS and characterize the underlying molecular mechanisms of PCOS using the networks. PCOS-associated genes were extracted from DisGeNet and the protein-protein interaction networks (PPIN) of PCOS were constructed using the String Database. Then we utilized MCODE algorithm to analyse the hub-gene modules from the PPIN. Finally, the major biological functions and signaling pathways involved in the hub modules were explored by functional enrichment analysis. A total of 522 candidate genes associated to PCOS were extracted from DisGeNET database. The PPIN constructed using the genes we have collected above included 488 genes and 2767 interaction relationships. Moreover, seven major gene modules were obtained after analyzing the PPIN with the use of MCODE plug-in. The major modules generated were enriched in certain biological functions such as cancer and cell proliferation and apoptosis, regulation of lipid and glucose metabolism, cell cycle and so on. The integrated analysis performed in the current study revealed that these hub modules and their related genes are closely associated to the pathogenesis of PCOS, which may probably provide novel insights for the treatment of PCOS and the study of its latent pathogenic mechanism. The relationship between several of the key genes including ALB, TOP2A, PTGER3, NPB and BRD2 in the modules and PCOS has not been investigated previously and it remains to be verified by further research of large sample, multi-center and multi-ethnic.

Developmental programming: prenatal testosterone-induced epigenetic modulation and its effect on gene expression in sheep ovary†

Maternal perturbations or sub-optimal conditions during fetal development can predispose the offspring to diseases in adult life. Animal and human studies show that prenatal androgen excess may be an underlying cause of polycystic ovary syndrome (PCOS) later in life. In women, PCOS is a common fertility disorder with comorbid metabolic dysfunction. Here, using a sheep model of PCOS phenotype, we elucidate the epigenetic changes induced by prenatal (30-90 day) testosterone (T) treatment and its effect on gene expression in fetal day 90 (D90) and adult year 2 (Y2) ovaries. RNA-seq study shows 65 and 99 differentially regulated genes in prenatal T-treated fetal and adult ovaries, respectively. Interestingly, there were no differences in gene inducing histone marks H3K27ac, H3K9ac, and H3K4me3 or in gene silencing marks, H3K27me3 and H3K9me3 in the fetal D90 ovaries of control and excess T-exposed fetuses. In contrast, except for H3K4me3 and H3K27me3, all the other histone marks were upregulated in the prenatal T-treated adult Y2 ovary. Chromatin immunoprecipitation (ChIP) studies in adult Y2 ovaries established a direct relationship between the epigenetic modifications with the upregulated and downregulated genes obtained from RNA-seq. Results show increased gene inducing marks, H3K27ac and H3K9ac, on the promoter region of upregulated genes while gene silencing mark, H3K9me3, was also significantly increased on the downregulated genes. This study provides a mechanistic insight into prenatal T-induced developmental programming and its effect on ovarian gene expression that may contribute to reproductive dysfunction and development of PCOS in adult life.

Dietary proanthocyanidins alleviated ovarian fibrosis in letrozole-induced polycystic ovary syndrome in rats

This study investigated the effects of proanthocyanidins (PCs) on ovarian fibrosis in letrozole-induced polycystic ovary syndrome (PCOS) in rats. The administration of PCs effectively reduced the body weight (BW) and relative ovarian weight in PCOS rats. ELISA results revealed that PCs significantly reduced the level of serum T, LH, LH/FSH in the PCOS group. In addition, qRT-PCR results revealed that treatment with PCs significantly increased the main antioxidant enzymes (Cat, Sod2, Gpx3, Mgst1, Gsta4, Sod1 and Prdx3) in PCOS rats. Also, the expression analysis of proteins by Western blotting revealed that PCs significantly decreased the level of TGF-βR1, p-Smad3, p-Smad2 and Smad4 and reversed the downregulation of Smad7 in PCOS rats. The study suggested that PCs improved ovarian fibrosis in PCOS rats by regulating the serum hormone level, inhibiting oxidative stress and suppressing the activation of the TGF-β1/Smads signaling pathway. PRACTICAL APPLICATIONS: Currently, plant extracts are being widely used to treat female reproductive and metabolic disorders. Particularly, proanthocyanidins (PCs), the well-known natural polyphenolic compounds, which are a significant source of antioxidants present in many colored fruits, are consumed as fruits as well as a dietary supplement to prevent many disorders. Recent pharmacological studies have reported that PCs have many health beneficial properties, such as antioxidant activity, improving cholesterol homeostasis, blood lipid regulatory properties, microcirculation improvement effect, antitumor activity and anti-aging activity. Despite these properties of PCs, the antifibrosis effect of PCs has not been studied to date. The main purpose of this study was to research the role and the mechanisms of PCs in ovarian fibrosis in PCOS rats.

Polycystic ovary syndrome is transmitted via a transgenerational epigenetic process

Polycystic ovary syndrome (PCOS) is the most common reproductive and metabolic disorder affecting women of reproductive age. PCOS has a strong heritable component, but its pathogenesis has been unclear. Here, we performed RNA sequencing and genome-wide DNA methylation profiling of ovarian tissue from control and third-generation PCOS-like mice. We found that DNA hypomethylation regulates key genes associated with PCOS and that several of the differentially methylated genes are also altered in blood samples from women with PCOS compared with healthy controls. Based on this insight, we treated the PCOS mouse model with the methyl group donor S-adenosylmethionine and found that it corrected their transcriptomic, neuroendocrine, and metabolic defects. These findings show that the transmission of PCOS traits to future generations occurs via an altered landscape of DNA methylation and propose methylome markers as a possible diagnostic landmark for the condition, while also identifying potential candidates for epigenetic-based therapy.

Insulin resistance and PCOS: chicken or egg?

PCOS is a common and heterogeneous endocrine disorder in women of reproductive age, frequently associated with metabolic abnormalities. It was estimated that about 75% of these subjects have an impairment of insulin action, as measured by gold standard methods. While the relationship between insulin resistance and PCOS is consistently shown by a number of studies, the mechanisms underlying its primary origin still remains an unsolved issue. Insulin resistance and the associated hyperinsulinemia can induce both the endocrine and reproductive traits of PCOS. However, androgen excess, in turn, can impair insulin action, directly and/or through several changes occurring in different tissues. Body fat excess, which is another common feature in these women, can contribute to worsening the whole picture. Nevertheless, insulin resistance may also be found in many normal-weight individuals. Endocrine and metabolic abnormalities can develop in different moments, and probably there is fetal programming of these alterations. However, a number of vicious circles, with bidirectional relationships between androgen excess and insulin resistance, and with the contribution of several other factors, make it extremely difficult to understand where this process really originates. This review summarizes available evidence on this topic, in order to better understand the complex relationships linking hyperandrogenism and impaired insulin action in women with PCOS.

Polycystic Ovary Syndrome: A Brain Disorder Characterized by Eating Problems Originating during Puberty and Adolescence

Polycystic ovary syndrome (PCOS) is an endocrine condition associated with reproductive and psychiatric disorders, and with obesity. Eating disorders, such as bulimia and recurrent dieting, are also linked to PCOS. They can lead to the epigenetic dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis, thereby impacting on ovarian folliculogenesis. We postulate that PCOS is induced by psychological distress and episodes of overeating and/or dieting during puberty and adolescence, when body dissatisfaction and emotional distress are often present. We propose that upregulated activation of the central HPG axis during this period can be epigenetically altered by psychological stressors and by bulimia/recurrent dieting, which are common during adolescence and which can lead to PCOS. This hypothesis is based on events that occur during a largely neglected stage of female reproductive development. To date, most research into the origins of PCOS has focused on the prenatal induction of this disorder, particularly in utero androgenization and the role of anti-Müllerian hormone. Establishing causality in our peripubertal model requires prospective cohort studies from infancy. Mechanistic studies should consider the role of the gut microbiota in addition to the epigenetic regulation of (neuro) hormones. Finally, clinicians should consider the importance of underlying chronic psychological distress and eating disorders in PCOS.

Prenatal Androgenization Alters the Development of GnRH Neuron and Preoptic Area RNA Transcripts in Female Mice

Polycystic ovary syndrome (PCOS) is the most common form of infertility in women. The causes of PCOS are not yet understood and both genetics and early-life exposure have been considered as candidates. With regard to the latter, circulating androgens are elevated in mid-late gestation in women with PCOS, potentially exposing offspring to elevated androgens in utero; daughters of women with PCOS are at increased risk for developing this disorder. Consistent with these clinical observations, prenatal androgenization (PNA) of several species recapitulates many phenotypes observed in PCOS. There is increasing evidence that symptoms associated with PCOS, including elevated luteinizing hormone (LH) (and presumably gonadotropin-releasing hormone [GnRH]) pulse frequency emerge during the pubertal transition. We utilized translating ribosome affinity purification coupled with ribonucleic acid (RNA) sequencing to examine GnRH neuron messenger RNAs from prepubertal (3 weeks) and adult female control and PNA mice. Prominent in GnRH neurons were transcripts associated with protein synthesis and cellular energetics, in particular oxidative phosphorylation. The GnRH neuron transcript profile was affected more by the transition from prepuberty to adulthood than by PNA treatment; however, PNA did change the developmental trajectory of GnRH neurons. This included families of transcripts related to both protein synthesis and oxidative phosphorylation, which were more prevalent in adults than in prepubertal mice but were blunted in PNA adults. These findings suggest that prenatal androgen exposure can program alterations in the translatome of GnRH neurons, providing a mechanism independent of changes in the genetic code for altered expression.

MiRNAs expression profiling of rat ovaries displaying PCOS with insulin resistance

Purpose

The present study established microRNA (miRNA) expression profiles for rat ovaries displaying polycystic ovary syndrome (PCOS) with insulin resistance and explored the underlying biological functions of differentially expressed miRNAs.

Methods

A PCOS with insulin resistance rat model was created by administering letrozole and a high-fat diet. Total RNA was extracted from the ovaries of PCOS with insulin resistance rats and normal rats. Three ovaries from each group were used to identify differentially expressed miRNAs by deep sequencing. A hierarchical clustering heatmap and volcano plot were used to display the pattern of differentially expressed miRNAs. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to explore the potential target genes of the differentially expressed miRNAs and identify their putative biological function. Nine of the differentially expressed miRNAs were selected for validation by Real-time Quantitative PCR (qRT-PCR).

Results

A total of 58 differentially expressed miRNAs were identified in the rat ovaries exhibiting PCOS with insulin resistance compared with control ovaries, including 23 miRNAs that were upregulated and 35 miRNAs that were downregulated. GO and KEGG pathway analyses revealed that the predicted target genes were related to metabolic processes, cellular processes, and metabolic pathways. Furthermore, qRT-PCR confirmed that miR-3585-5p and miR-30-5p were significantly upregulated and miR-146-5p was downregulated in the ovaries of PCOS with insulin resistance rats compared with the controls.

Conclusion

These results indicate that differentially expressed miRNAs in rat ovaries may be involved in the pathophysiology of insulin resistance in PCOS. Our study may be beneficial in establishing miRNAs as novel diagnostic and therapeutic biomarkers for insulin resistance in PCOS.

Is There a Bidirectional Association between Polycystic Ovarian Syndrome and Periodontitis? A Systematic Review and Meta-analysis

Polycystic ovary syndrome (PCOS) has reproductive and metabolic properties that may be linked to periodontitis (PD). This study aimed to update and render a robust critical assessment on all evidence linking PCOS and PD, and appraising a hypothetical bidirectional association. Five databases (PubMed, Scholar, EMBASE, Web of Science and CENTRAL) were searched up to May 2020. Case-control and cohort studies on the association of PCOS and PD were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Random effects meta-analyses of standardized mean difference (SMD) and risk ratio (RR) were performed. We followed Strength of Recommendation Taxonomy (SORT) to appraise the strength and quality of the evidence. Twelve case-controls fulfilled the inclusion criteria (876 with PCOS and 48170 healthy controls), all scored as having a low risk of bias. Meta-analysis revealed that PCOS females have 28% more risk towards PD, and PD females have 46% more risk to have PCOS. PCOS females with PD had higher gum bleeding, periodontal pocket depth and clinical attachment loss than non-PCOS females with PD. Populations with undefined periodontal status contribute to underestimated results. On the basis of the available evidence, it is possible to assume a bidirectional link between PCOS and PD. That is, PCOS increases by 28% the risk of having PD and in the same fashion, PD increases by 46% the risk of having PCOS. Furthermore, women with PCOS were associated with worsening clinical characteristics and inflammation of PD. These findings suggest that PCOS and PD may be linked. Hence, further prospective and clinical trial studies with nonsurgical periodontal therapy are necessary to clarify the existence of an increased risk of PCOS in women with PD and vice-versa.

DNA methylation in promoter regions of genes involved in the reproductive and metabolic function of children born to women with PCOS

Clinical and experimental evidences indicate that epigenetic modifications induced by the prenatal environment are related to metabolic and reproductive derangements in polycystic ovary syndrome (PCOS). Alterations in the leptin and adiponectin systems, androgen signalling and antimüllerian hormone (AMH) levels have been observed in PCOS women and in their offspring. Using a targeted Next-Generation Sequencing (NGS), we studied DNA methylation in promoter regions of the leptin (LEP), leptin receptor (LEPR), adiponectin (ADIPOQ), adiponectin receptor 1 and 2 (ADIPOR1 and ADIPOR2), AMH and androgen receptor (AR) genes in 24 sons and daughters of women with PCOS (12 treated with metformin during pregnancy) and 24 children born to non-PCOS women during early infancy (2-3 months of age). Genomic DNA was extracted from whole blood, bisulphite converted and sequenced by NGS. Girls showed differences between groups in 1 CpG site of LEPR, 2 of LEP, 1 of ADIPOR2 and 2 of AR. Boys showed differences in 5 CpG sites of LEP, 3 of AMH and 9 of AR. Maternal metformin treatment prevented some of these changes in LEP, ADIPOR2 and partially in AR in girls, and in LEP and AMH in boys. Maternal BMI at early pregnancy was inversely correlated with the methylation levels of the ChrX-67544981 site in the whole group of girls (r = -0.530, p = 0.008) and with the global Z-score in all boys (r = -0.539, p = 0.007). These data indicate that the intrauterine PCOS environment predisposes the offspring to acquire certain sex-dependent DNA methylation patterns in the promoter regions of metabolic and reproductive genes.

Le syndrome des ovaires polykystiques : quelles nouveautés en 2019 ?

PolyCystic Ovary Syndrome (PCOS) is the first endocrinopathy of women of child-bearing age and the leading cause of anovulatory infertility. The pathophysiology of this syndrome is complex and involves genetic traits highlighted by GWAS and epigenetic traits with DNA methylation modifications. Initially described as an ovarian disease, works carried out over recent years were turned towards neuroendocrine disorder involving GABAergic pathways, KNDy neurons and a possible role of prenatal androgen exposure determined by animal models. Clinically, PCOS leads to many complications including psychological and emotional disorders demonstrated in large populations of PCOS women. © 2019 Published by Elsevier Masson SAS. All rights reserved. Cet article fait partie du numéro supplément Les Must de l'Endocrinologie 2019 réalisé avec le soutien institutionnel de Ipsen-Pharma.

Mitochondrial dysfunction: An emerging link in the pathophysiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by irregular menstrual cycles, hyperandrogenism and subfertility. Due to its complex manifestation, the pathogenic mechanism of PCOS is not well defined. Cumulative effect of altered genetic and epigenetic factors along with environmental factors may play a role in the manifestation of PCOS leading to systemic malfunction. With failure of genome-wide association study (GWAS) and other studies performed on nuclear genome to provide any clue for precise mechanism of PCOS pathogenesis, attention has been diverted to mitochondria. Mitochondrion plays an important role in cellular metabolic functions and is linked to Insulin Resistance (IR). Recently, increasing reports suggest that mitochondrial dysfunction may be a contributing factor in the pathogenesis of PCOS. Hence, in this review, we have discussed mitochondrial biology in brief and emphasizes on genetic and epigenetic aspects of mitochondrial dysfunction studied in PCOS women and PCOS-like animal models. We also highlight underlying mechanism behind mitochondrial dysfunction contributing to PCOS and its related complications such as obesity, diabetes, cardiovascular diseases, metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and cancer. Furthermore, contrasting remarks against involvement of mitochondrial dysfunction in PCOS pathophysiology have also been presented. This review enhances our understanding in relation to mitochondrial dysfunction in the etiology of PCOS and stimulates further research to explore a clear link between mitochondrial dysfunction and PCOS pathogenesis and progression. Understanding pathogenic mechanisms underlying PCOS will open new windows to develop promising therapeutic strategies against PCOS.

Naturally Occurring and Experimentally Induced Rhesus Macaque Models for Polycystic Ovary Syndrome: Translational Gateways to Clinical Application

Indian rhesus macaque nonhuman primate models for polycystic ovary syndrome (PCOS) implicate both female hyperandrogenism and developmental molecular origins as core components of PCOS etiopathogenesis. Establishing and exploiting macaque models for translational impact into the clinic, however, has required multi-year, integrated basic-clinical science collaborations. Paradigm shifting insight has accrued from such concerted investment, leading to novel mechanistic understanding of PCOS, including hyperandrogenic fetal and peripubertal origins, epigenetic programming, altered neural function, defective oocytes and embryos, adipogenic constraint enhancing progression to insulin resistance, pancreatic decompensation and type 2 diabetes, together with placental compromise, all contributing to transgenerational transmission of traits likely to manifest in adult PCOS phenotypes. Our recent demonstration of PCOS-related traits in naturally hyperandrogenic (High T) female macaques additionally creates opportunities to employ whole genome sequencing to enable exploration of gene variants within human PCOS candidate genes contributing to PCOS-related traits in macaque models. This review will therefore consider Indian macaque model contributions to various aspects of PCOS-related pathophysiology, as well as the benefits of using macaque models with compellingly close homologies to the human genome, phenotype, development and aging.

A Narrative Review of Placental Contribution to Adverse Pregnancy Outcomes in Women With Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. In pregnancy, women with PCOS experience increased risk of miscarriage, gestational diabetes, preeclampsia, and extremes of fetal birth weight, and their offspring are predisposed to reproductive and cardiometabolic dysfunction in adulthood. Pregnancy complications, adverse fetal outcomes, and developmental programming of long-term health risks are known to have placental origins. These findings highlight the plausibility of placental compromise in pregnancies of women with PCOS.

EVIDENCE SYNTHESIS

A comprehensive PubMed search was performed using terms "polycystic ovary syndrome," "placenta," "developmental programming," "hyperandrogenism," "androgen excess," "insulin resistance," "hyperinsulinemia," "pregnancy," and "pregnancy complications" in both human and animal experimental models.

CONCLUSIONS

There is limited human placental research specific to pregnancy of women with PCOS. Gestational androgen excess and insulin resistance are two clinical hallmarks of PCOS that may contribute to placental dysfunction and underlie the higher rates of maternal-fetal complications observed in pregnancies of women with PCOS. Additional research is needed to prevent adverse maternal and developmental outcomes in women with PCOS and their offspring.

DNA methylation in the pathogenesis of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the leading endocrine and metabolic disorder in premenopausal women characterized by hyperandrogenism and abnormal development of ovarian follicles. To date, the PCOS etiology remains unclear and has been related to insulin resistance, obesity, type 2 diabetes mellitus, cardiovascular disease and infertility, among other morbidities. Substantial evidence illustrates the impact of genetic, intrauterine and environmental factors on the PCOS etiology. Lately, epigenetic factors have garnered considerable attention in the pathogenesis of PCOS considering that changes in the content of DNA methylation, histone acetylation and noncoding RNAs have been reported in various tissues of women with this disease. DNA methylation is changed in the peripheral and umbilical cord blood, as well as in ovarian and adipose tissue of women with PCOS, suggesting the involvement of this epigenetic modification in the pathogenesis of the disease. Perhaps, these defects in DNA methylation promote the deregulation of genes involved in inflammation, hormone synthesis and signaling and glucose and lipid metabolism. Research on the role of DNA methylation in the pathogenesis of PCOS is just beginning, and several issues await investigation. This review aims to provide an overview of current research focused on DNA methylation and PCOS, as well as discuss the perspectives regarding this topic.

Hyperandrogenic origins of polycystic ovary syndrome - implications for pathophysiology and therapy

INTRODUCTION

Polycystic ovary syndrome (PCOS) diagnosis comprises combinations of female hyperandrogenism, menstrual irregularity and polycystic ovaries. While it is a familial and highly prevalent endocrine disorder, progress towards a cure is hindered by absence of a definitive pathogenic mechanism and lack of an animal model of naturally occurring PCOS.

AREAS COVERED

These include an overview of PCOS and its potential etiology, and an examination of insights gained into its pathogenic origins. Animal models derived from experimentally-induced hyperandrogenism during gestation, or from naturally-occurring PCOS-like traits, most reliably demonstrate reproductive, neuroendocrine and metabolic pathogenesis.

EXPERT OPINION

Genetic studies, while identifying at least 17 PCOS risk genes, account for <10% of women with PCOS. A number of PCOS risk genes involve regulation of gonadotropin secretion or action, suggesting a reproductive neuroendocrine basis for PCOS pathogenesis. Consistent with this notion, a number of animal models employing fetal androgen excess demonstrate epigenetic induction of PCOS-like traits, including reproductive neuroendocrine and metabolic dysfunction. Monkey models are most comprehensive, while mouse models provide molecular insight, including identifying the androgen receptor, particularly in neurons, as mediating androgen-induced PCOS-like programming. Naturally-occurring female hyperandrogenism is also demonstrated in monkeys. Animal models are poised to delineate molecular gateways to PCOS pathogenesis.

Comparison of Androgen Levels, Endocrine and Metabolic Indices, and Clinical Findings in Women with Polycystic Ovary Syndrome in Uygur and Han Ethnic Groups from Xinjiang Province in China

BACKGROUND The aim of this study was to compare androgen levels, endocrine and metabolic indices, and clinical findings in women with polycystic ovary syndrome (PCOS) in Uygur and Han ethnic groups from Xinjiang Province, China. MATERIAL AND METHODS Between January 2016 to May 2017 clinical data were collected from Uygur (N=82) and Han (N=100) women diagnosed with PCOS, including age, body mass index (BMI), the Ferriman-Gallwey (mFG) hirsutism score, and waist-to-hip ratio (WHR). Blood samples obtained from all study participants were used to measure androgenic steroid levels, including androgen, androstenedione, dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), and the free androgen index (FAI). Endocrine indices measured included sex-hormone binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), and prolactin (PL). Metabolic indices measured included insulin, glucose, total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), triglyceride (TG), and low-density lipoprotein (LDL). RESULTS The FAI in Uygur women with PCOS (4.89) was significantly increased compared with Han women with PCOS (2.78) (p<0.05); androgen levels were significantly correlated with the FAI, glucose, insulin, TC, HDL, and LDL (p<0.05); androstenedione levels were positively correlated with glucose and insulin levels (p<0.05). In Han women with PCOS, androgen levels were negatively correlated with TG levels and positively correlated with TC levels (p<0.05); the FAI was positively correlated with glucose and insulin levels (p<0.05). CONCLUSIONS There were significant differences in androgen levels, endocrine, and metabolic indices in women with PCOS between the Uygur and Han ethnic groups from Xinjiang Province in China.