Causal mechanisms and balancing selection inferred from genetic associations with polycystic ovary syndrome

Fructose 1-phosphate, an evolutionary signaling molecule of abundancy

Evidence is accumulating that specifically fructose exerts adverse cardiometabolic effects in humans. Recent experimental studies have shown that fructose not only serves as a substrate for, among others, intrahepatic lipid formation, but also has a signaling function. It is postulated that fructose 1-phosphate (F1-P) has evolved as a signaling molecule of abundancy that stimulates nutrient absorption, lipid storage, and reproduction. Such a role would provide an explanation for why fructose contributes to the pathogenesis of evolutionary mismatch diseases, including nonalcoholic fatty liver disease (NAFLD), cardiovascular disease, polycystic ovary syndrome (PCOS), and colorectal cancer, in the current era of nutritional abundance. It is anticipated that reducing F1-P, by either pharmacological inhibition of ketohexokinase (KHK) or societal measures, will mitigate the risk of these diseases.

Shared genetic basis between reproductive behaviors and anxiety-related disorders

Reproductive behaviors are associated with risks for psychiatric disorders. Reproductive phenotypes are moderately heritable and have genetic overlaps with risks for psychiatric disorders. However, the genetic and causal relationships between anxiety-related disorders or specific anxiety disorders and reproductive phenotypes remain unknown. We utilized large-scale genome-wide association study (GWAS) results (n = 9537-542,901) for five reproductive phenotypes [age at menarche, age at first sexual intercourse (AFS), age at first birth (AFB), number of children ever born (NEB), and age at menopause] and five anxiety-related disorders [panic disorder, anxiety disorders from the ANGST and the UK biobank (UKBB), posttraumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD)]. To assess genetic correlations and causal associations, linkage disequilibrium score regression and Mendelian randomization analyses, respectively, were performed. We found that AFS and AFB were negatively correlated with anxiety disorders ANGST (AFS: r_g ± SE = -0.28 ± 0.08, p = 6.00 × 10^-4; AFB: -0.45 ± 0.11, p = 3.26 × 10^-5), anxiety disorders UKBB (AFS: -0.18 ± 0.03, p = 9.64 × 10^-9; AFB; -0.25 ± 0.03, p = 2.90 × 10^-13) and PTSD (AFS: -0.42 ± 0.12, p = 4.00 × 10^-4; AFB: -0.44 ± 0.12, p = 2.00 × 10^-4) and positively correlated with OCD (AFS: 0.25 ± 0.05, p = 2.46 × 10^-6; AFB: 0.25 ± 0.05, p = 3.92 × 10^-7). Conversely, NEB was negatively correlated with OCD (-0.28 ± 0.08, p = 6.00 × 10^-4). We revealed bidirectional effects between earlier AFS and AFB and anxiety disorders (odds ratios: OR_{earlier AFS→Anxiety} = 1.64, p = 2.27 × 10^-8; OR_{earlier AFB→Anxiety} = 1.15, p = 2.28 × 10^-3; OR_{Anxiety→earlier AFS} = 1.02, p = 6.62 × 10^-8; OR_{Anxiety→earlier AFB} = 1.08, p = 1.60 × 10^-4). In contrast, we observed unidirectional effects of later AFS and AFB on OCD (OR_{later AFS→OCD} = 2.18, p = 2.16 × 10^-6; OR_{later AFB→OCD} = 1.22, p = 0.016). We suggest that those who have earlier sexual debut and childbirth are prone to risk for anxiety disorders and vice versa, while those who have later sexual debut and childbirth are genetically prone to risk for OCD. Our findings further support revising the diagnostic criteria (DSM-5) such that OCD is independent from anxiety disorders.

Combined Transcriptomic and Metabolomic Analysis of Women with Polycystic Ovary Syndrome

Background. Polycystic ovary syndrome (PCOS) is a complex class of endocrine disorders with insulin resistance, compensatory hyperinsulinemia, and obesity. However, the pathogenesis and therapies of PCOS have not been fully elucidated. Exosomal miRNAs have the potential to serve as biomarkers and therapies for a wide range of medical conditions. Method. We collected follicular fluid from 5 PCOS patients and 5 healthy people. High-throughput sequencing technology to identify differentially expressed miRNAs and untargeted metabolome identify differential metabolites in follicular fluid exosomal. RT-qPCR and AUC analysis were performed. Result. miRNA high-throughput sequencing identified 124 differential miRNAs. RT-qPCR analysis confirmed the sequencing results. These differential miRNA target genes are mainly involved in metabolic pathways. Metabolomics studies identified 31 differential metabolites. miRNA and lncRNA coexpression networks in metabolic pathways rigorously screened 28 differentially expressed miRNAs. This network would identify miRNA signatures associated with metabolic processes in PCOS. Meanwhile, the area under curve of receiver operating characteristic revealed that hsa-miR-196a-3p, hsa-miR-143-5p, hsa-miR-106a-3p, hsa-miR-34a-5p, and hsa-miR-20a-5p were potential biomarkers for the diagnosis of PCOS. Conclusion. Collectively, these results demonstrate the potential pathogenesis of PCOS, and follicular fluid exosomal miRNAs may be efficient targets for the diagnosis and treatment of PCOS in long-term clinical studies.

Long-term health outcomes in young women with polycystic ovary syndrome: A narrative review

Polycystic ovary syndrome (PCOS) has long been recognized as a common disorder in young women leading to reproductive and cutaneous sequelae. However, the associated health risks are now known to extend beyond these familiar manifestations to a range of longer-term comorbidities. Here we review the evidence for an association of PCOS with adverse long-term health outcomes, discussing the pathophysiological mechanisms involved in addition to opportunities for therapeutic intervention. Cross-sectional and longitudinal studies point to an increased risk of type 2 diabetes, hypertension and dyslipidaemia, with recent data confirming that these translate to an increased risk of cardiovascular events independently of obesity. Obstructive sleep apnoea, nonalcoholic fatty liver disease and endometrial cancer are also more prevalent, while mental health disorders, notably anxiety and depression, are common but under-appreciated associations. Uncertainties remain as to whether these risks are apparent in all patients with PCOS or are confined to particular subtypes, whether risks persist post-menopausally and how risk may be affected by ethnicity. Further work is also needed in establishing if systematic screening and targeted intervention can lead to improved outcomes. Until such data are available, clinicians managing women with PCOS should counsel patients on long-term health risks and invest in strategies that limit progression to metabolic and non-metabolic morbidities.

Clinical management of pregnancy in women with polycystic ovary syndrome: An expert opinion

Polycystic ovary syndrome (PCOS) is associated with a higher risk for pregnancy and birth complications according to the specific features associated with PCOS. The features include obesity before and during pregnancy, hyperandrogenism, insulin resistance, infertility, cardiometabolic risk factors, and poor mental health. PCOS is not often recognized as a risk factor for poor pregnancy and birth outcomes in pregnancy care guidelines, while its associated features are. Pregnancy-related risk profile should ideally be assessed for modifiable risk factors (e.g., lifestyle and weight management) at preconception in women with PCOS. Hyperglycaemia should be screened using a 75-g oral glucose tolerance test at preconception or within the first 20 weeks of pregnancy if it has not been performed at preconception and should be repeated at 24-28 weeks of pregnancy. In the absence of evidence of benefit for strategies specific to women with PCOS, the international evidence-based guidelines for the assessment and management of PCOS recommend screening, optimizing, and monitoring risk profile in women with PCOS (at preconception, during and postpregnancy) consistent with the recommendations for the general population. Recommended factors include blood glucose, weight, blood pressure, smoking, alcohol, diet, exercise, sleep and mental health, emotional, and sexual health among women with PCOS. The guidelines recommend Metformin in addition to lifestyle for assisting with weight management and improving cardiometabolic risk factors, particularly in those with overweight or obesity. Letrozole is considered the first-line pharmacological treatment for anovulatory infertility in PCOS. Individualized approach should be considered in the management of pregnancy in PCOS.

Out of step societal and Darwinian adaptation during evolution is the cause of multiple women's health issues

During human evolution, major changes in our societal conditions and environment took place without sufficient time for concomitant genetic alterations, leading to out of step adaptation and diseases in women. We first discuss recent societal adaptation mismatch (menstrual bleeding; increases in cancers of reproductive organs, endometriosis; mother's nursing; polycystic ovarian syndrome; transgenerational epigenetic modifications), followed by Darwinian out of step adaptation (labor difficulties; sex chromosomes, human diseases and sex disparity in genomic DNA). We discuss the evolutionary basis of menstrual bleeding, followed by recent increases in cancers of reproductive organs and endometriosis. The importance of breastfeeding by mothers is also emphasized. Earlier onset of menarche, decreased rates of childbirths and breastfeeding resulted in increased number of menstrual cycles in a lifetime, coupled with excess estrogen exposure and incessant ovulation, conditions that increased the susceptibility to mammary and uterine cancers as well as ovarian epithelial cancer and endometriosis. Shorter lactation duration in mothers also contributed to more menstrual cycles. We further discuss the evolutionary basis of the prevalent polycystic ovary syndrome. During the long-term Darwinian evolution, difficulties in childbirth evolved due to a narrowed pelvis, our upright walking and enlarged fetal brain sizes. Because there are 1.5% genomic DNA differences between woman and man, it is of significance to investigate sex-specific human physiology and diseases. In conclusion, understanding out of step adaptation during evolution could allow the prevention and better management of female reproductive dysfunction and diseases.

A GWAS in Idiopathic/Unexplained Infertile Men Detects a Genomic Region Determining Follicle-Stimulating Hormone Levels

CONTEXT

Approximately 70% of infertile men are diagnosed with idiopathic (abnormal semen parameters) or unexplained (normozoospermia) infertility, with the common feature of lacking etiologic factors. Follicle-stimulating hormone (FSH) is essential for initiation and maintenance of spermatogenesis. Certain single-nucleotide variations (SNVs; formerly single-nucleotide polymorphisms [SNPs]) (ie, FSHB c.-211G > T, FSHR c.2039A > G) are associated with FSH, testicular volume, and spermatogenesis. It is unknown to what extent other variants are associated with FSH levels and therewith resemble causative factors for infertility.

OBJECTIVE

We aimed to identify further genetic determinants modulating FSH levels in a cohort of men presenting with idiopathic or unexplained infertility.

METHODS

We retrospectively (2010-2018) selected 1900 men with idiopathic/unexplained infertility. In the discovery study (n = 760), a genome-wide association study (GWAS) was performed (Infinium PsychArrays) in association with FSH values (Illumina GenomeStudio, v2.0). Minor allele frequencies (MAFs) were analyzed for the discovery and an independent normozoospermic cohort. In the validation study (n = 1140), TaqMan SNV polymerase chain reaction was conducted for rs11031005 and rs10835638 in association with andrological parameters.

RESULTS

Imputation revealed 9 SNVs in high linkage disequilibrium, with genome-wide significance (P < 4.28e-07) at the FSHB locus 11p.14.1 being associated with FSH. The 9 SNVs accounted for up to a 4.65% variance in FSH level. In the oligozoospermic subgroup, this was increased up to 6.95% and the MAF was enhanced compared to an independent cohort of normozoospermic men. By validation, a significant association for rs11031005/rs10835638 with FSH (P = 4.71e-06/5.55e-07) and FSH/luteinizing hormone ratio (P = 2.08e-12/6.4e-12) was evident.

CONCLUSIONS

This GWAS delineates the polymorphic FSHB genomic region as the main determinant of FSH levels in men with unexplained or idiopathic infertility. Given the essential role of FSH, molecular detection of one of the identified SNVs that causes lowered FSH and therewith decreases spermatogenesis could resolve the idiopathic/unexplained origin by this etiologic factor.

Role of Single Nucleotide Variants in the YAP1 Gene in Adolescents with Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in women. It can manifest in adolescence, affecting up to 8% of adolescents. Long-term health consequences characteristic of PCOS are impaired fertility, increased risk of type 2 diabetes, metabolic disorders and cardiovascular disease. All of these sequelae are exacerbated by increased body weight, a major feature of PCOS. The protein encoded by the YAP1 gene plays a key role in one of the pivotal mechanisms that govern cellular/organismal metabolism and contributes to the pathogenesis of metabolic diseases. Aim: To compare the prevalence of single nucleotide variants (SNVs) in the YAP1 gene among adolescents with PCOS, adolescents at risk of PCOS development and healthy adolescents, and assess their association with the clinical characteristics of PCOS. Results: The frequencies of the five investigated YAP1 gene SNVs (rs11225161, rs11225166, rs3858420, rs11225138 and rs79981660) were not significantly different among adolescents with PCOS, risk group patients and healthy controls. Furthermore, none of the SNVs contributed to the clinical characteristics of adolescents with PCOS and adolescents at risk of PCOS development. Conclusions: No significant associations were found between PCOS in adolescents and the five investigated SNVs in the YAP1 gene.

Glial cells as integrators of peripheral and central signals in the regulation of energy homeostasis

Communication between the periphery and the brain is key for maintaining energy homeostasis. To do so, peripheral signals from the circulation reach the brain via the circumventricular organs (CVOs), which are characterized by fenestrated vessels lacking the protective blood-brain barrier (BBB). Glial cells, by virtue of their plasticity and their ideal location at the interface of blood vessels and neurons, participate in the integration and transmission of peripheral information to neuronal networks in the brain for the neuroendocrine control of whole-body metabolism. Metabolic diseases, such as obesity and type 2 diabetes, can disrupt the brain-to-periphery communication mediated by glial cells, highlighting the relevance of these cell types in the pathophysiology of such complications. An improved understanding of how glial cells integrate and respond to metabolic and humoral signals has become a priority for the discovery of promising therapeutic strategies to treat metabolic disorders. This Review highlights the role of glial cells in the exchange of metabolic signals between the periphery and the brain that are relevant for the regulation of whole-body energy homeostasis.

Causality of anthropometric markers associated with polycystic ovarian syndrome: Findings of a Mendelian randomization study

Introduction

Using body mass index (BMI) as a proxy, previous Mendelian randomization (MR) studies found total causal effects of general obesity on polycystic ovarian syndrome (PCOS). Hitherto, total and direct causal effects of general- and central obesity on PCOS have not been comprehensively analyzed.

Objectives

To investigate the causality of central- and general obesity on PCOS using surrogate anthropometric markers.

Methods

Summary GWAS data of female-only, large-sample cohorts of European ancestry were retrieved for anthropometric markers of central obesity (waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR)) and general obesity (BMI and its constituent variables–weight and height), from the IEU Open GWAS Project. As the outcome, we acquired summary data from a large-sample GWAS (118870 samples; 642 cases and 118228 controls) within the FinnGen cohort. Total causal effects were assessed via univariable two-sample Mendelian randomization (2SMR). Genetic architectures underlying causal associations were explored. Direct causal effects were analyzed by multivariable MR modelling.

Results

Instrumental variables demonstrated no weak instrument bias (F > 10). Four anthropometric exposures, namely, weight (2.69–77.05), BMI (OR: 2.90–4.06), WC (OR: 6.22–20.27), and HC (OR: 6.22–20.27) demonstrated total causal effects as per univariable 2SMR models. We uncovered shared and non-shared genetic architectures underlying causal associations. Direct causal effects of WC and HC on PCOS were revealed by two multivariable MR models containing exclusively the anthropometric markers of central obesity. Other multivariable MR models containing anthropometric markers of both central- and general obesity showed no direct causal effects on PCOS.

Conclusions

Both and general- and central obesity yield total causal effects on PCOS. Findings also indicated potential direct causal effects of normal weight-central obesity and more complex causal mechanisms when both central- and general obesity are present. Results underscore the importance of addressing both central- and general obesity for optimizing PCOS care.

Assessment of THADA gene polymorphisms in a sample of Colombian women with polycystic ovary syndrome: A pilot study

Polycystic ovary syndrome (PCOS) is a multifactorial and polygenic endocrine-metabolic disorder in women of reproductive age. SNPs in the THADA gene have been identified as PCOS risk loci. In this study, we evaluated the frequency of five polymorphisms in a sample of Colombian women with PCOS, and their association with clinical and endocrine-metabolic parameters. Forty-nine women with PCOS and forty-nine healthy women were included. Allelic discrimination was performed in the THADA gene by iPLEX and the MassARRAY system (Agena Bioscience). Haploview software was conducted to analyze the linkage disequilibrium (LD) and haplotypes of polymorphisms. There was an association between the genotypes TT of rs12468394, CC + AA of rs12468394, and GG of rs6544661 and an increase in the levels of free testosterone. The CC + AA of rs12468394 genotype also was associated with an increase of androstenedione levels. THADA gene SNPs were not associated with PCOS risk. There was very strong LD among the SNPs. No significant differences in the frequency of haplotypes between groups were observed. The statistical power of this analysis is low because of the small number of samples analyzed. Additional studies involving large populations of Colombian women with PCOS are needed to verify the role of the THADA gene in this disorder.

The role of gonadotropin-releasing hormone neurons in polycystic ovary syndrome

Given the critical central role of gonadotropin-releasing hormone (GnRH) neurons in fertility, it is not surprising that the GnRH neural network is implicated in the pathology of polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility. Although many symptoms of PCOS relate most proximately to ovarian dysfunction, the central reproductive neuroendocrine system ultimately drives ovarian function through its regulation of anterior pituitary gonadotropin release. The typical cyclical changes in frequency of GnRH release are often absent in women with PCOS, resulting in a persistent high-frequency drive promoting gonadotropin changes (i.e., relatively high luteinizing hormone and relatively low follicle-stimulating hormone concentrations) that contribute to ovarian hyperandrogenemia and ovulatory dysfunction. However, the specific mechanisms underpinning GnRH neuron dysfunction in PCOS remain unclear. Here, we summarize several preclinical and clinical studies that explore the causes of aberrant GnRH secretion in PCOS and the role of disordered GnRH secretion in PCOS pathophysiology.

Polycystic ovary syndrome: a "risk-enhancing" factor for cardiovascular disease

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age and is hallmarked by hyperandrogenism, oligo-ovulation, and polycystic ovarian morphology. Polycystic ovary syndrome, particularly the hyperandrogenism phenotype, is associated with several cardiometabolic abnormalities, including obesity, dyslipidemia, elevated blood pressure, and prediabetes or type 2 diabetes. Many, but not all, studies have suggested that PCOS is associated with increased risk of cardiovascular disease (CVD), including coronary heart disease and stroke, independent of body mass index and traditional risk factors. Interpretation of the data from these observational studies is limited by the varying definitions and ascertainment of PCOS and CVD across studies. Recent Mendelian randomization studies have challenged the causality of PCOS with coronary heart disease and stroke. Future longitudinal studies with clearly defined PCOS criteria and newer genetic methodologies may help to determine association and causality. Nevertheless, CVD risk screening remains critical in this patient population, as improvements in metabolic profile and reduction in CVD risk are achievable with a combination of lifestyle management and pharmacotherapy. Statin therapy should be implemented in women with PCOS who have elevated atherosclerotic CVD risk. If CVD risk is uncertain, measurement of subclinical atherosclerosis (carotid plaque or coronary artery calcium) may be a useful tool to guide shared decision-making about initiation of statin therapy. Other medications, such as metformin and glucagon-like peptide-1 receptor agonists, also may be useful in reducing CVD risk in insulin-resistant populations. Additional research is needed to determine the best pathways to mitigate PCOS-associated CVD risk.

The polygamous GnRH neuron: Astrocytic and tanycytic communication with a neuroendocrine neuronal population

To ensure the survival of the species, hypothalamic neuroendocrine circuits controlling fertility, which converge onto neurons producing gonadotropin-releasing hormone (GnRH), must respond to fluctuating physiological conditions by undergoing rapid and reversible structural and functional changes. However, GnRH neurons do not act alone, but through reciprocal interactions with multiple hypothalamic cell populations, including several glial and endothelial cell types. For instance, it has long been known that in the hypothalamic median eminence, where GnRH axons terminate and release their neurohormone into the pituitary portal blood circulation, morphological plasticity displayed by distal processes of tanycytes modifies their relationship with adjacent neurons as well as the spatial properties of the neurohemal junction. These alterations not only regulate the capacity of GnRH neurons to release their neurohormone, but also the activation of discrete non-neuronal pathways that mediate feedback by peripheral hormones onto the hypothalamus. Additionally, a recent breakthrough has demonstrated that GnRH neurons themselves orchestrate the establishment of their neuroendocrine circuitry during postnatal development by recruiting an entourage of newborn astrocytes that escort them into adulthood and, via signalling through gliotransmitters such as prostaglandin E2, modulate their activity and GnRH release. Intriguingly, several environmental and behavioural toxins perturb these neuron-glia interactions and consequently, reproductive maturation and fertility. Deciphering the communication between GnRH neurons and other neural cell types constituting hypothalamic neuroendocrine circuits is thus critical both to understanding physiological processes such as puberty, oestrous cyclicity and aging, and to developing novel therapeutic strategies for dysfunctions of these processes, including the effects of endocrine disruptors.

Maternal hyperandrogenism is associated with a higher risk of type 2 diabetes mellitus and overweight in adolescent and adult female offspring: a long-term population-based follow-up study

PURPOSE

Adverse intrauterine environment may predispose offspring to cardio-metabolic dysfunction in later life. In this study, we aimed to investigate the effects of maternal hyperandrogenism (MH) on cardio-metabolic risk factors in female offspring in later life.

METHODS

This prospective population-based study included 211 female offspring with MH and 757 female offspring without MH (controls). Both groups were followed from baseline to the date of incidence of events, censoring, or end of the study period, whichever came first. Age scaled unadjusted and adjusted cox regression models were applied to assess the hazard ratios (HR) and 95% confidence intervals (CIs) for the association of MH with pre-diabetes (pre-DM), type 2 diabetes mellitus (T2DM), overweight and obesity in offspring of both groups. Statistical analysis was performed using the software package STATA; significance level was set at P < 0.05.

RESULTS

This study revealed a higher risk of T2DM (unadjusted HR 2.67, 95% CI 1.33-5.36) and overweight (unadjusted HR 1.41, 95% CI 1.06-1.88) in female offspring with MH, compared to controls. Results remained unchanged after adjustment for potential confounders including body mass index, education, physical activity, mother's age at delivery, birth weight, and childhood obesity. However, no significant difference was observed in the risk of pre-DM and obesity in females with MH, compared to controls in both unadjusted and adjusted models.

CONCLUSION

This pioneer study with a long-term follow-up demonstrated that MH increases the risk of developing T2DM and being overweight in female offspring in later life. Further long-term population-based studies are needed to confirm these findings.

Changes in individual polycystic ovary syndrome phenotypical characteristics over time: a long-term follow-up study

OBJECTIVE

To assess the effects of aging on the features of polycystic ovary syndrome (PCOS).

DESIGN

Cohort study.

SETTING

Tertiary care center.

PATIENT(S)

Women with PCOS, diagnosed according to the 2003 Rotterdam criteria, who visited our outpatient clinic repeatedly.

INTERVENTION(S)

Comparisons were made between the first visit and consecutive visits.

MAIN OUTCOME MEASURE(S)

Change in PCOS phenotype groups in terms of clinical and endocrine characteristics.

RESULT(S)

A total of 596 women visited the outpatient clinic repeatedly. An estimated change per 5-year age showed a decrease in the prevalence of phenotype A and an increase in the prevalence of not having PCOS. The serum levels of testosterone, androstenedione, and dehydroepiandrosterone sulfate as well as the free androgen index decreased significantly. Clinical characteristics showed an increase in terms of body mass index and waist circumference, whereas plasma glucose levels, insulin levels, and insulin resistance did not change significantly.

CONCLUSION(S)

The prevalence of PCOS phenotype groups changes over time. There is an important age effect that indicates a more regular menstrual cycle, decrease in the serum androgen levels, and improvement in polycystic ovarian morphology when aging occurs in women with PCOS.

Polycystic Ovary Syndrome and the Neuroendocrine Consequences of Androgen Excess

Polycystic ovary syndrome (PCOS) is a major endocrine disorder strongly associated with androgen excess and frequently leading to female infertility. Although classically considered an ovarian disease, altered neuroendocrine control of gonadotropin-releasing hormone (GnRH) neurons in the brain and abnormal gonadotropin secretion may underpin PCOS presentation. Defective regulation of GnRH pulse generation in PCOS promotes high luteinizing hormone (LH) pulsatile secretion, which in turn overstimulates ovarian androgen production. Early and emerging evidence from preclinical models suggests that maternal androgen excess programs abnormalities in developing neuroendocrine circuits that are associated with PCOS pathology, and that these abnormalities are sustained by postpubertal elevation of endogenous androgen levels. This article will discuss experimental evidence, from the clinic and in preclinical animal models, that has significantly contributed to our understanding of how androgen excess influences the assembly and maintenance of neuroendocrine impairments in the female brain. Abnormal central gamma-aminobutyric acid (GABA) signaling has been identified in both patients and preclinical models as a possible link between androgen excess and elevated GnRH/LH secretion. Enhanced GABAergic innervation and drive to GnRH neurons is suspected to contribute to the pathogenesis and early manifestation of neuroendocrine derangement in PCOS. Accordingly, this article also provides an overview of GABA regulation of GnRH neuron function from prenatal development to adulthood to discuss possible avenues for future discovery research and therapeutic interventions. © 2022 American Physiological Society. Compr Physiol 12:3347-3369, 2022.

Genome-Wide Association Study and Polygenic Risk Scores of Serum DHEAS Levels in a Chilean Children Cohort

CONTEXT

Adrenarche reflects the developmental growth of the adrenal zona reticularis, which produces increasing adrenal androgen secretion (eg, dehydroepiandrosterone [DHEA]/dehydroepiandrosterone sulfate [DHEAS]) from approximately age 5 to 15 years.

OBJECTIVE

We hypothesized that the study of the genetic determinants associated with variations in serum DHEAS during adrenarche might detect genetic variants influencing the rate or timing of this process.

METHODS

Genome-wide genotyping was performed in participants of the Chilean pediatric Growth and Obesity Chilean Cohort Study (GOCS) cohort (n = 788). We evaluated the genetic determinants of DHEAS levels at the genome-wide level and in targeted genes associated with steroidogenesis. To corroborate our findings, we evaluated a polygenic risk score (PRS) for age at pubarche, based on the discovered variants, in children from the same cohort.

RESULTS

We identified one significant variant at the genome-wide level in the full cohort, close to the GALR1 gene (P = 3.81 × 10-8). In addition, variants suggestive of association (P < 1 × 10-5) were observed in PRLR, PITX1, PTPRD, NR1H4, and BCL11B. Stratifying by sex, we found variants suggestive of association in SERBP1 and CAMTA1/VAMP3 for boys and near ZNF98, TRPC6, and SULT2A1 for girls. We also found significant reductions in age at pubarche in those children with higher PRS for greater DHEAS based on these newly identified variants.

CONCLUSION

Our results disclose one variant associated with DHEAS concentrations at the level of genome-wide association study significance, and several variants with a suggestive association that may be involved in the genetic regulation of adrenarche.

Novel Hub genes co-expression network mediates dysfunction in a model of polycystic ovary syndrome

BACKGROUND

This study aimed to integrate DNA methylation, miRNA, and mRNA microarray data to construct a gene co-expression network for polycystic ovarian syndrome (PCOS).

METHODS

The weighted gene co-expression network analysis (WGCNA) was conducted to construct a PCOS-related co-expression network by using the GEO public datasets. We performed Gene Ontology and KEGG pathway enrichment analyses for a further exploration of gene function in networks. Finally, the dysfunction module consisting of a co-expression network was mapped to the PCOS patients and tried to provide guidance to the PCOS phenotyping.

RESULTS

Three modules (Midnightbule, Pink, and Red) were identified to be PCOS-related by WGCNA analysis. These module-related genes were enriched in cell response to stimulus, PI3K-Akt signaling pathway, insulin biological process, signaling pathway, and cytokine-cytokine receptor interaction biological processes. The multiple-factor network, including miRNA-lncRNA and DNA methylation-mRNA interaction, was closely associated with PCOS dysfunction.

CONCLUSION

Our study render a novel insight into the mechanisms and might provide candidate biomarkers and therapeutic targets for the classification of PCOS dysfunction.

Polycystic Ovarian Syndrome: A Complex Disease with a Genetics Approach

Polycystic ovarian syndrome (PCOS) is a complex endocrine disorder affecting females in their reproductive age. The early diagnosis of PCOS is complicated and complex due to overlapping symptoms of this disease. The most accepted diagnostic approach today is the Rotterdam Consensus (2003), which supports the positive diagnosis of PCOS when patients present two out of the following three symptoms: biochemical and clinical signs of hyperandrogenism, oligo, and anovulation, also polycystic ovarian morphology on sonography. Genetic variance, epigenetic changes, and disturbed lifestyle lead to the development of pathophysiological disturbances, which include hyperandrogenism, insulin resistance, and chronic inflammation in PCOS females. At the molecular level, different proteins and molecular and signaling pathways are involved in disease progression, which leads to the failure of a single genetic diagnostic approach. The genetic approach to elucidate the mechanism of pathogenesis of PCOS was recently developed, whereby four phenotypic variances of PCOS categorize PCOS patients into classic, ovulatory, and non-hyperandrogenic types. Genetic studies help to identify the root cause for the development of this PCOS. PCOS genetic inheritance is autosomal dominant but the latest investigations revealed it as a multigene origin disease. Different genetic loci and specific genes have been identified so far as being associated with this disease. Genome-wide association studies (GWAS) and related genetic studies have changed the scenario for the diagnosis and treatment of this reproductive and metabolic condition known as PCOS. This review article briefly discusses different genes associated directly or indirectly with disease development and progression.

Causes and Consequences of Polycystic Ovary Syndrome: Insights From Mendelian Randomization

CONTEXT

Although polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age, risk factors that may cause the syndrome are poorly understood. Based on epidemiologic studies, PCOS is thought to cause several adverse outcomes such as cardiovascular disease; however, the common presence of comorbidities such as obesity may be responsible for such associations, rather than PCOS in and of itself. To overcome the limitations of observational studies, investigators have employed Mendelian randomization (MR), which uses genetic variants to interrogate causality between exposures and outcomes.

EVIDENCE ACQUISITION

To clarify causes and consequences of PCOS, this review will describe MR studies involving PCOS, both as an exposure and as an outcome. The literature was searched using the terms "Mendelian randomization," "polycystic ovary syndrome," "polycystic ovarian syndrome," and "PCOS" (to May 2021).

EVIDENCE SYNTHESIS

MR studies have suggested that obesity, testosterone levels, fasting insulin, serum sex hormone-binding globulin concentrations, menopause timing, male-pattern balding, and depression may play a causal role in PCOS. In turn, PCOS may increase the risk of estrogen receptor-positive breast cancer, decrease the risk of endometrioid ovarian cancer, and have no direct causal effect on type 2 diabetes, coronary heart disease, or stroke.

CONCLUSIONS

The accumulation of genome-wide association studies in PCOS has enabled multiple MR analyses identifying factors that may cause PCOS or be caused by PCOS. This knowledge will be critical to future development of measures to prevent PCOS in girls at risk as well as prevent complications in those who have PCOS.

Genomic correlation, shared loci, and causal relationship between obesity and polycystic ovary syndrome: a large-scale genome-wide cross-trait analysis

BACKGROUND

The comorbidity between polycystic ovary syndrome (PCOS) and obesity has long been observed in clinical settings, but their shared genetic basis remains unclear.

METHODS

Leveraging summary statistics of large-scale GWAS(s) conducted in European-ancestry populations on body mass index (adult BMI, Nfemale=434,794; childhood BMI, N=39,620), waist-to-hip ratio (WHR, Nfemale=381,152), WHR adjusted for BMI (WHRadjBMI, Nfemale=379,501), and PCOS (Ncase=10,074, Ncontrol=103,164), we performed a large-scale genome-wide cross-trait analysis to quantify overall and local genetic correlation, to identify shared loci, and to infer causal relationship.

RESULTS

We found positive genetic correlations between PCOS and adult BMI (rg=0.47, P=2.19×10-16), childhood BMI (rg=0.31, P=6.72×10-5), and WHR (rg=0.32, P=1.34×10-10), all withstanding Bonferroni correction. A suggestive significant genetic correlation was found between PCOS and WHRadjBMI (rg=0.09, P=0.04). Partitioning the whole genome into 1703 nearly independent regions, we observed a significant local genetic correlation for adult BMI and PCOS at chromosome 18: 57630483-59020751. We identified 16 shared loci underlying PCOS and obesity-related traits via cross-trait meta-analysis including 9 loci shared between BMI and PCOS (adult BMI and PCOS: 5 loci; childhood BMI and PCOS: 4 loci), 6 loci shared between WHR and PCOS, and 5 loci shared between WHRadjBMI and PCOS. Mendelian randomization (MR) supported the causal roles of both adult BMI (OR=2.92, 95% CI=2.33-3.67) and childhood BMI (OR=2.76, 95% CI=2.09-3.66) in PCOS, but not WHR (OR=1.19, 95% CI=0.93-1.52) or WHRadjBMI (OR=1.03, 95% CI=0.87-1.22). Genetic predisposition to PCOS did not seem to influence the risk of obesity-related traits.

CONCLUSIONS

Our cross-trait analysis suggests a shared genetic basis underlying obesity and PCOS and provides novel insights into the biological mechanisms underlying these complex traits. Our work informs public health intervention by confirming the important role of weight management in PCOS prevention.

Further delineation of familial polycystic ovary syndrome (PCOS) via whole-exome sequencing: PCOS-related rare FBN3 and FN1 gene variants are identified

AIM

To identify pathogenic rare coding Mendelian/high-effect size variant(s) by whole-exome sequencing in familial polycystic ovary syndrome (PCOS) patients to elucidate PCOS-related pathways.

METHODS

Twenty women and their affected available relatives diagnosed with PCOS according to Rotterdam criteria were recruited. Whole-exome sequencing on germ-line DNA from 31 PCOS probands and their affected relatives was performed. Whole-exome sequencing data were further evaluated by pathway and chemogenomics analyses. In-slico analysis of candidate variants were done by VarCards for functional predictions and VarSite for impact on three-dimensional (3D) structures in the candidate proteins.

RESULTS

Two heterozygous rare FBN3 missense variants in three patients, and one FN1 missense variant in one patient from three different PCOS families were identified.

CONCLUSION

We identified three novel FBN3 and FN1 variants for the first time in the literature and linked with PCOS. Further functional studies may identify causality of these newly discovered PCOS-related variants, and their role yet remains to be investigated. Our findings may improve our understanding of the biological pathways affected and identify new drug targets.

Leveraging Northern European population history: novel low-frequency variants for polycystic ovary syndrome

STUDY QUESTION

Can we identify novel variants associated with polycystic ovary syndrome (PCOS) by leveraging the unique population history of Northern Europe?

SUMMARY ANSWER

We identified three novel genome-wide significant associations with PCOS, with two putative independent causal variants in the checkpoint kinase 2 (CHEK2) gene and a third in myosin X (MYO10).

WHAT IS KNOWN ALREADY

PCOS is a common, complex disorder with unknown aetiology. While previous genome-wide association studies (GWAS) have mapped several loci associated with PCOS, the analysis of populations with unique population history and genetic makeup has the potential to uncover new low-frequency variants with larger effects.

STUDY DESIGN, SIZE, DURATION

A population-based case-control GWAS was carried out.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We identified PCOS cases from national registers by ICD codes (ICD-10 E28.2, ICD-9 256.4, or ICD-8 256.90), and all remaining women were considered controls. We then conducted a three-stage case-control GWAS: in the discovery phase, we had a total of 797 cases and 140 558 controls from the FinnGen study. For validation, we used an independent dataset from the Estonian Biobank, including 2812 cases and 89 230 controls. Finally, we performed a joint meta-analysis of 3609 cases and 229 788 controls from both cohorts. Additionally, we reran the association analyses including BMI as a covariate, with 2169 cases and 160 321 controls from both cohorts.

MAIN RESULTS AND THE ROLE OF CHANCE

Two out of the three novel genome-wide significant variants associating with PCOS, rs145598156 (P = 3.6×10-8, odds ratio (OR) = 3.01 [2.02-4.50] minor allele frequency (MAF) = 0.005) and rs182075939 (P = 1.9×10-16, OR = 1.69 [1.49-1.91], MAF = 0.04), were found to be enriched in the Finnish and Estonian populations and are tightly linked to a deletion c.1100delC (r2 = 0.95) and a missense I157T (r2 = 0.83) in CHEK2. The third novel association is a common variant near MYO10 (rs9312937, P = 1.7 × 10-8, OR = 1.16 [1.10-1.23], MAF = 0.44). We also replicated four previous reported associations near the genes Erb-B2 Receptor Tyrosine Kinase 4 (ERBB4), DENN Domain Containing 1A (DENND1A), FSH Subunit Beta (FSHB) and Zinc Finger And BTB Domain Containing 16 (ZBTB16). When adding BMI as a covariate only one of the novel variants remained genome-wide significant in the meta-analysis (the EstBB lead signal in CHEK2 rs182075939, P = 1.9×10-16, OR = 1.74 [1.5-2.01]) possibly owing to reduced sample size.

LARGE SCALE DATA

The age- and BMI-adjusted GWAS meta-analysis summary statistics are available for download from the GWAS Catalog with accession numbers GCST90044902 and GCST90044903.

LIMITATIONS, REASONS FOR CAUTION

The main limitation was the low prevalence of PCOS in registers; however, the ones with the diagnosis most likely represent the most severe cases. Also, BMI data were not available for all (63% for FinnGen, 76% for EstBB), and the biobank setting limited the accessibility of PCOS phenotypes and laboratory values.

WIDER IMPLICATIONS OF THE FINDINGS

This study encourages the use of isolated populations to perform genetic association studies for the identification of rare variants contributing to the genetic landscape of complex diseases such as PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This work has received funding from the European Union's Horizon 2020 research and innovation programme under the MATER Marie Skłodowska-Curie grant agreement No. 813707 (N.P.-G., T.L., T.P.), the Estonian Research Council grant (PRG687, T.L.), the Academy of Finland grants 315921 (T.P.), 321763 (T.P.), 297338 (J.K.), 307247 (J.K.), 344695 (H.L.), Novo Nordisk Foundation grant NNF17OC0026062 (J.K.), the Sigrid Juselius Foundation project grants (T.L., J.K., T.P.), Finska Läkaresällskapet (H.L.) and Jane and Aatos Erkko Foundation (H.L.). The funders had no role in study design, data collection and analysis, publishing or preparation of the manuscript. The authors declare no conflicts of interest.

The PNA mouse may be the best animal model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) exerts negative effects on females of childbearing age. It is important to identify more suitable models for fundamental research on PCOS. We evaluated animal models from a novel perspective with the aim of helping researchers select the best model for PCOS. RNA sequencing was performed to investigate the mRNA expression profiles in the ovarian tissues of mice with dehydroepiandrosterone (DHEA) plus high-fat diet (HFD)-induced PCOS. Meanwhile, 14 datasets were obtained from the Gene Expression Omnibus (GEO), including eight studies on humans, three on rats and three on mice, and genes associated with PCOS were obtained from the PCOSKB website. We compared the consistency of each animal model and human PCOS in terms of DEGs and pathway enrichment analysis results. There were 239 DEGs shared between prenatally androgenized (PNA) mice and PCOS patients. Moreover, 1113 genes associated with PCOS from the PCOSKB website were identified among the DEGs of PNA mice. A total of 134 GO and KEGG pathways were shared between PNA mice and PCOS patients. These findings suggest that the PNA mouse model is the best animal model to simulate PCOS.

Identification of 371 genetic variants for age at first sex and birth linked to externalising behaviour

Age at first sexual intercourse and age at first birth have implications for health and evolutionary fitness. In this genome-wide association study (age at first sexual intercourse, N = 387,338; age at first birth, N = 542,901), we identify 371 single-nucleotide polymorphisms, 11 sex-specific, with a 5-6% polygenic score prediction. Heritability of age at first birth shifted from 9% [CI = 4-14%] for women born in 1940 to 22% [CI = 19-25%] for those born in 1965. Signals are driven by the genetics of reproductive biology and externalising behaviour, with key genes related to follicle stimulating hormone (FSHB), implantation (ESR1), infertility and spermatid differentiation. Our findings suggest that polycystic ovarian syndrome may lead to later age at first birth, linking with infertility. Late age at first birth is associated with parental longevity and reduced incidence of type 2 diabetes and cardiovascular disease. Higher childhood socioeconomic circumstances and those in the highest polygenic score decile (90%+) experience markedly later reproductive onset. Results are relevant for improving teenage and late-life health, understanding longevity and guiding experimentation into mechanisms of infertility.

Managing reproductive problems in women with epilepsy of childbearing age

Girls and women constitute nearly 50% of all epilepsy cases. Apart from the disease symptoms, epilepsy and antiseizure medications (ASMs) may also affect the reproductive function, pregnancy and even the health of their offspring. Therefore, it is very important to identify and summarize the problems and risks for women with epilepsy (WWE) of childbearing age, and offer internationally recognized methods through multidisciplinary collaboration. In this review, we summarize the reproduction-related problems with WWE and propose multidisciplinary management by epileptologists, gynecologists and obstetricians, as well as other experts, from preconception to delivery. Large, multicenter registries are needed to advance our knowledge on new ASMs and their effects on WWE and their offspring.

Mendelian Randomization Analysis Identified Potential Genes Pleiotropically Associated with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder with unclear etiology. Some genes may be pleiotropically or potentially causally associated with PCOS. In the present study, the summary data-based Mendelian randomization (SMR) method integrating genome-wide association study (GWAS) for PCOS and expression quantitative trait loci (eQTL) data was applied to identify genes that were pleiotropically associated with PCOS. Separate SMR analysis was performed using eQTL data in the ovary and whole blood. Although no genes showed significant pleiotropic association with PCOS after correction for multiple testing, some of the genes exhibited suggestive significance. RPS26 showed the strongest suggestive pleiotropic association with PCOS in both SMR analyses (β[SE]=0.10[0.03], P_SMR=1.72×10^-4 for ovary; β[SE]=0.11[0.03], P_SMR=1.40×10^-4 for whole blood). PM20D1 showed the second strongest suggestive pleiotropic association with PCOS in the SMR analysis using eQTL data for the whole blood and was also among the top ten hit genes in the SMR analysis using eQTL data for the ovary. Two other genes, including CTC-457L16.2 and NEIL2, were among the top ten hit genes in both SMR analyses. In conclusion, this study revealed multiple genes that were potentially involved in the pathogenesis of PCOS.

Suicide Related Phenotypes in a Bipolar Sample: Genetic Underpinnings

Suicide in Bipolar Disorder (BD) is a relevant clinical concern. Genetics may shape the individual risk for suicide behavior in BD, together with known clinical factors. The lack of consistent replication in BD may be associated with its multigenetic component. In the present contribution we analyzed a sample of BD individuals (from STEP-BD database) to identify the genetic variants potentially associated with three different suicide-related phenotypes: (1) a feeling that the life was not worth living; (2) fantasies about committing a violent suicide; (3) previous attempted suicide. The sample under analysis included 1115 BD individuals. None of the SNPs reached genome-wide significance. However, a trend of association was evidenced for rs2767403, an intron variant of AOPEP gene, in association with phenotype #1 (p = 5.977 × 10⁻⁶). The molecular pathway analysis showed a significant enrichment in all the investigated phenotypes on pathways related to post synaptic signaling, neurotransmission and neurodevelopment. Further, NOTCH signaling or the γ-aminobutyric acid (GABA)-ergic signaling were found to be associated with specific suicide-related phenotypes. The present investigation contributes to the hypothesis that the genetic architecture of suicide behaviors in BD is related to alteration of entire pathways rather than single genes. In particular, our molecular pathway analysis points on some specific molecular events that could be the focus of further research in this field.

Natural History of Polycystic Ovary Syndrome and New Advances in the Epidemiology

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women, affecting up to 15% of the female population. The natural history of the syndrome is complex, including both androgen exposure in early life and adiposity-driven dysfunction involving also dysregulated, also involving altered hypothalamus-ovarian crosstalk. The manifestations can arise as early as childhood or puberty onward, suggesting that genetic susceptibility is an important etiological factor. In adulthood, women with PCOS present with reproductive, metabolic, and psychological health issues at a population-based level. Epidemiological studies on large datasets offer an excellent opportunity to evaluate health effects and costs related to the syndrome. Hospital or insurance-based datasets are also available; however, the results are not representative of the female population in the community. More longitudinal studies spanning from early childhood to late adulthood are needed to assess the long-term health impact and early manifestations of PCOS. Moreover, the identification of women with PCOS from large datasets can be expensive. Self-reported symptoms or PCOS diagnosis may offer a feasible approach.

Erbb4 regulates the oocyte microenvironment during folliculogenesis

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders leading to infertility in women affecting reproductive, endocrine and metabolic systems. Recent genomewide association studies on PCOS cohorts revealed a single nucleotide polymorphism (SNP) in the ERBB4 receptor tyrosine kinase 4 gene, but its role in ovary development or during folliculogenesis remains poorly understood. Since no genetic animal models mimicking all PCOS reproductive features are available, we conditionally deleted Erbb4 in murine granulosa cells (GCs) under the control of Amh promoter. While we have demonstrated that Erbb4 deletion displayed aberrant ovarian function by affecting the reproductive function (asynchronous oestrous cycle leading to few ovulations and subfertility) and metabolic function (obesity), their ovaries also present severe structural and functional abnormalities (impaired oocyte development). Hormone analysis revealed an up-regulation of serum luteinizing hormone, hyperandrogenism, increased production of ovarian and circulating anti-Müllerian hormone. Our data implicate that Erbb4 deletion in GCs leads to defective intercellular junctions between the GCs and oocytes, causing changes in the expression of genes regulating the local microenvironment of the follicles. In vitro culture assays reducing the level of Erbb4 via shRNAs confirm that Erbb4 is essential for regulating Amh level. In conclusion, our results indicate a functional role for Erbb4 in the ovary, especially during folliculogenesis and its reduced expression plays an important role in reproductive pathophysiology, such as PCOS development.

Pathogenetic analysis of polycystic ovary syndrome from the perspective of omics

Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disease, involving multiple genes, multiple pathways, and complex hormone secretion processes. Hence, the pathogenesis of PCOS cannot be explained by a single factor. Omics analysis includes genomics, transcriptomics, and proteomics, which are fast and effective methods for studying the pathogenesis of diseases. PCOS is primarily characterized by androgen excess, and reproductive and metabolic dysfunctions. The application of omics analysis in the body fluids, blood, cells or tissues of women with PCOS offers the potential for unexpected molecular advantages in explaining new mechanisms of PCOS etiology and pathophysiology, and provides new perspectives for identifying potential biomarkers and developing new therapeutic targets. At present, several omics analyses have been applied to produce complex datasets. In this manuscript, the recent advances in omics research on PCOS are summarized, aiming at an important and parallel review of the newly published research.

Replication study and meta-analysis of selected genetic variants and polycystic ovary syndrome susceptibility in Asian population

PURPOSE

Polycystic ovary syndrome (PCOS) is a highly complex disorder influenced by genetic and environmental factors. Previous association studies have identified multiple PCOS-susceptible loci, but there is no consistent conclusion, which calls for further investigations.

METHODS

In the present case-control study, FSHR gene variants (rs2268361, rs6165, and rs6166), LHCGR gene variant (rs13405728), THADA gene variant (rs13429458), DENND1A gene variants (rs10818854 and rs2479106), and INSR gene variants (rs2059807 and rs1799817) were genotyped with Sanger sequencing in a total of 400 PCOS women and 480 healthy women.

RESULTS

After Bonferroni correction, our results showed that rs13405728, rs13429458, rs2479106, rs10818854, and rs2059807 were significantly associated with PCOS risk in Chinese women. To improve the statistical strength, a further meta-analysis in Asian population was conducted. Although rs6166 and rs1799817 were not associated with PCOS risk in the present study, they were identified to be strongly associated with PCOS risk in the pooled Koreans and Chinese respectively. No significant association with PCOS risk was consistently found for rs2268361 or rs6165. Moreover, the pooled results further confirmed the significant association with PCOS risk for rs13405728, rs13429458, rs2479106, rs10818854, and rs2059807.

CONCLUSIONS

Collectively, the rs6166, rs13405728, rs13429458, rs2479106, rs10818854, rs2059807, and rs1799817 may indeed be the genetic risk factors for PCOS in Asian population, which requires further investigation using larger independent sets of samples in different ethnic populations.

Conceptualization of functional single nucleotide polymorphisms of polycystic ovarian syndrome genes: an in silico approach

PURPOSE

Polycystic ovarian syndrome (PCOS) is a multi-faceted endocrinopathy frequently observed in reproductive-aged females, causing infertility. Cumulative evidence revealed that genetic and epigenetic variations, along with environmental factors, were linked with PCOS. Deciphering the molecular pathways of PCOS is quite complicated due to the availability of limited molecular information. Hence, to explore the influence of genetic variations in PCOS, we mapped the GWAS genes and performed a computational analysis to identify the SNPs and their impact on the coding and non-coding sequences.

METHODS

The causative genes of PCOS were searched using the GWAS catalog, and pathway analysis was performed using ClueGO. SNPs were extracted using an Ensembl genome browser, and missense variants were shortlisted. Further, the native and mutant forms of the deleterious SNPs were modeled using I-TASSER, Swiss-PdbViewer, and PyMOL. MirSNP, PolymiRTS, miRNASNP3, and SNP2TFBS, SNPInspector databases were used to find SNPs in the miRNA binding site and transcription factor binding site (TFBS), respectively. EnhancerDB and HaploReg were used to characterize enhancer SNPs. Linkage Disequilibrium (LD) analysis was performed using LDlink.

RESULTS

25 PCOS genes showed interaction with 18 pathways. 7 SNPs were predicted to be deleterious using different pathogenicity predictions. 4 SNPs were found in the miRNA target site, TFBS, and enhancer sites and were in LD with reported PCOS GWAS SNPs.

CONCLUSION

Computational analysis of SNPs residing in PCOS genes may provide insight into complex molecular interactions among genes involved in PCOS pathophysiology. It may also aid in determining the causal variants and consequently contributing to predicting disease strategies.

Predictors of hypertensive disorders in pregnancy in women with and without polycystic ovary syndrome: The Australian Longitudinal Study of Women's Health

OBJECTIVES

A higher risk of hypertensive disorders in pregnancy (HDP) is frequently reported in women with polycystic ovary syndrome (PCOS). These women, however, have a higher risk profile for HDP compared with women without PCOS. The aim of this study was to elucidate the impact of PCOS per se on the incidence of HDP through post hoc subgroup analyses of the Australian Longitudinal Study on Women's Health by level of risk.

DESIGN

Longitudinal study.

PATIENTS

Of a total of 14,247 participants, 5838 women met the inclusion criteria. Eligible women were required to report PCOS and HDP status in at least one pregnancy within the study.

MEASUREMENTS

Included risk factors were age, body mass index, country of birth, parity, multiple pregnancy, subfertility, infertility treatment (hormonal vs. in vitro fertilization), gestational diabetes (GDM), family history of GDM and socioeconomic status. Longitudinal association between PCOS and HDP was assessed the using Cox proportional hazard regression with Efron's method.

RESULTS

While PCOS was associated with a higher incidence of HDP in a univariate model [hazard ratio (HR): 1.34, 95% confidence interval (CI): 1.05, 1.72], the significance was not retained after adjustment for risk factors [HR: 1.19, 95% CI: 0.79, 1.79]. However in multivariate analysis of subgroups, PCOS remained significantly associated with higher risk of HDP in non-obese women only [HR: 1.77, 95% CI: 1.11, 2.82].

CONCLUSIONS

Higher risk of HDP in PCOS is likely related to risk factors other than PCOS.

Replication study of THADA rs13429458 variant with PCOS susceptibility and its related traits in Indian women

AIM

The aetiopathogenesis of the multigenic multifactorial endocrinopathy, polycystic ovary syndrome (PCOS) has been explored using linkage, candidate gene and genome-wide association studies. Contradictory reports of replication studies attributed to phenotypic, ethnic and geographic variations are available. In this study, we investigated the association of Han Chinese GWAS polymorphism (rs13429458) in thyroid adenoma-associated gene (THADA) with PCOS susceptibility and its related traits in Indian women.

METHODS

We genotyped rs13429458 of THADA by direct sequencing and investigated its association with PCOS and its related traits in controls (N = 150) and PCOS women (N = 348). All women were extensively phenotyped in terms of anthropometric, hormonal and metabolic parameters. Association of polymorphism with PCOS risk and its related traits was carried out by regression analysis.

RESULTS

Genotypic and allele frequencies for rs13429458 were not different between controls and PCOS. Women with PCOS carrying variant allele showed significantly reduced fasting glucose levels, and decreased free and bioavailable testosterone and free androgen index.

CONCLUSION

To our knowledge, this is the first study to demonstrate that although this polymorphism does not alter PCOS susceptibility, it favorably impacts glucose metabolism and hyperandrogenism in Indian women with PCOS only. This study highlights that genetic predisposition markers for PCOS may differ with ethnicity and phenotypic variations.

Sex hormone-binding globulin: biomarker and hepatokine?

Over the past decade, there have been important breakthroughs in our understanding of the regulation and function of sex hormone-binding globulin (SHBG). A recent genome-wide association and Mendelian randomization study has provided new insights at the population level. Thorough study of genetic variants affecting serum SHBG has identified de novo lipogenesis as one of the mechanistic links between the metabolic syndrome and reduced serum SHBG levels in humans. Furthermore, careful deduction of the Mendelian randomization results suggests a direct, causal role for SHBG in the pathogenesis of type 2 diabetes, as a hepatokine, in women. These findings prompt the development of SHBG-raising therapies as a means to prevent or treat disorders such as type 2 diabetes and polycystic ovary syndrome.

Association Analysis of CYP11A1 Variants with Polycystic Ovary Syndrome: a Case-Control Study from North India

The most common multifactorial endocrine disorder in females of reproductive age is polycystic ovary syndrome (PCOS), affecting about 5-10% of females worldwide and 9.3% of females in India. Androgen excess in PCOS is caused as a result of defects in steroidogenesis genes. CYP11A1 is an imperative marker in the steroid synthesis pathway, and the altered expression of CYP11A1 has been reported to disrupt the synthesis of steroids and hence conferring risk for the development of PCOS. The present study aimed to analyze genetic variants (rs11632698, rs4077582, rs4887139) of CYP11A1 with PCOS from North India. The study included 270 PCOS females diagnosed according to Rotterdam 2003 criteria and 270 age-matched healthy non-PCOS females. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the genotypic analysis of the selected genetic variants. Association analysis of biochemical parameters (cholesterol, triglyceride, high-density lipoprotein) and anthropometric measurements with PCOS cases was done. The genetic variants of CYP11A1 (rs11632698, rs4077582, and rs4887139) demonstrated significant association with PCOS cases (p=1.0E-12, p=3.0E-3, p=1.0E-2, respectively). Binary logistic regression revealed that the dominant model of rs11632698 conferred 2.0 risk, and dominant as well as the co-dominant model of rs4887139 conferred risk of 2.2 and 2.4 fold, respectively, towards the progression of PCOS. The overall mean triglyceride levels were elevated, and mean HDL levels were lower in PCOS cases as compared to threshold values. The significant association of studied genetic variants suggested the important role of CYP11A1 in susceptibility to PCOS. The study was the first of its kind from our region and provided baseline data of genetics of PCOS.

DeepGP: An Integrated Deep Learning Method for Endocrine Disease Gene Prediction Using Omics Data

Endocrinology is the study focusing on hormones and their actions. Hormones are known as chemical messengers, released into the blood, that exert functions through receptors to make an influence in the target cell. The capacity of the mammalian organism to perform as a whole unit is made possible based on two principal control mechanisms, the nervous system and the endocrine system. The endocrine system is essential in regulating growth and development, tissue function, metabolism, and reproductive processes. Endocrine diseases such as diabetes mellitus, Grave's disease, polycystic ovary syndrome, and insulin-like growth factor I deficiency (IGFI deficiency) are classical endocrine diseases. Endocrine dysfunction is also an increasing factor of morbidity in cancer and other dangerous diseases in humans. Thus, it is essential to understand the diseases from their genetic level in order to recognize more pathogenic genes and make a great effort in understanding the pathologies of endocrine diseases. In this study, we proposed a deep learning method named DeepGP based on graph convolutional network and convolutional neural network for prioritizing susceptible genes of five endocrine diseases. To test the performance of our method, we performed 10-cross-validations on an integrated reported dataset; DeepGP obtained a performance of the area under the curve of ∼83% and area under the precision-recall curve of ∼65%. We found that type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) share most of their associated genes; therefore, we should pay more attention to the rest of the genes related to T1DM and T2DM, respectively, which could help in understanding the pathogenesis and pathologies of these diseases.

Distal Enhancer Potentiates Activin- and GnRH-Induced Transcription of FSHB

FSH is critical for fertility. Transcription of FSHB, the gene encoding the beta subunit, is rate-limiting in FSH production and is regulated by both GnRH and activin. Activin signals through SMAD transcription factors. Although the mechanisms and importance of activin signaling in mouse Fshb transcription are well-established, activin regulation of human FSHB is less well understood. We previously reported a novel enhancer of FSHB that contains a fertility-associated single nucleotide polymorphism (rs10031006) and requires a region resembling a full (8 base-pair) SMAD binding element (SBE). Here, we investigated the role of the putative SBE within the enhancer in activin and GnRH regulation of FSHB. In mouse gonadotrope-derived LβT2 cells, the upstream enhancer potentiated activin induction of both the human and mouse FSHB proximal promoters and conferred activin responsiveness to a minimal promoter. Activin induction of the enhancer required the SBE and was blocked by the inhibitory SMAD7, confirming involvement of the classical SMAD signaling pathway. GnRH induction of FSHB was also potentiated by the enhancer and dependent on the SBE, consistent with known activin/GnRH synergy regulating FSHB transcription. In DNA pull-down, the enhancer SBE bound SMAD4, and chromatin immunoprecipitation demonstrated SMAD4 enrichment at the enhancer in native chromatin. Combined activin/GnRH treatment elevated levels of the active transcriptional histone marker, histone 3 lysine 27 acetylation, at the enhancer. Overall, this study indicates that the enhancer is directly targeted by activin signaling and identifies a novel, evolutionarily conserved mechanism by which activin and GnRH can regulate FSHB transcription.

Polycystic Ovary Syndrome Susceptibility Loci Inform Disease Etiological Heterogeneity

Polycystic ovary syndrome (PCOS) is a complex disorder with heterogenous phenotypes and unclear etiology. A recent phenotypic clustering study identified metabolic and reproductive subtypes of PCOS. We hypothesize that the heterogeneity of PCOS manifestations reflects different mechanistic pathways and can be identified using a genetic approach. We applied k-means clustering to categorize the genome-wide significant PCOS variants into clusters based on their associations with selected quantitative traits that likely reflect PCOS etiological pathways. We evaluated the association of each cluster with PCOS-related traits and disease outcomes. We then applied Mendelian randomization to estimate the causal effects between the traits and PCOS. Three categories of variants were identified: adiposity, insulin resistant, and reproductive. Significant associations were observed for variants in the adiposity cluster with body mass index (BMI), waist circumference and breast cancer, and variants in the insulin-resistant cluster with fasting insulin, glucose values, and homeostatic model assessment of insulin resistance (HOMA-IR). Sex hormone binding globulin (SHBG) has strong association with all three clusters. Mendelian randomization suggested a causal role of BMI and SHBG on PCOS. No causal associations were observed for PCOS on disease outcomes.

3 CpG methylation biomarkers for the diagnosis of polycystic ovary syndrome (PCOS) in blood

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disease in women that seriously interferes with the patient's metabolic and reproductive functions. The current diagnostic criteria for PCOS are expert-based and still disputed. Previous studies have identified changes in DNA methylation in peripheral blood of women with PCOS, but their diagnostic potential for PCOS remains to be studied.

OBJECTIVE

The present study aimed to identify potential methylation biomarkers for the diagnosis of PCOS in blood.

METHODS

Methylation profiles of peripheral blood were downloaded from a public database, Gene Expression Omnibus (GEO), of 30 PCOS patients (diagnosed with the revised 2003 Rotterdam consensus criteria), and 30 age-matched healthy women were recruited from the Centre of Reproductive Medicine, Linyi People's Hospital, Shandong, China. Weighted gene co-expression network analysis (WGCNA) was utilized to identify PCOS-related co-methylation CpG sites (co-MPs). Functional enrichment analysis was performed on the localized genes of PCOS-related co-MPs. The least absolute shrinkage and selection operator (LASSO) regression was used to screen CpG methylation signatures for PCOS diagnosis and receiver operating characteristic (ROC) analysis was conducted to evaluate their diagnostic accuracy, respectively. To assess the accuracy of the combination of the investigated indicators, multivariate ROC analysis was performed on the predicted probability values obtained using binary logistic regression on the methylation levels of selected CpGs together.

RESULTS

Seven co-methylation modules were obtained, most relevant to PCOS of which was the turquoise module, containing 194 co-MPs. The genes that these co-MPs located in were mainly associated with the immune-related pathway. According to LASSO regression, three Co-MPs (cg23464743, cg06834912, cg00103771) were identified as potential diagnostic biomarkers of PCOS. ROC analysis showed an AUC (area under the curve) of 0.7556 (sensitivity 60.0%, specificity 83.3%) for cg23464743, 0.7822 (sensitivity 70.0%, specificity 80.0%) for cg06834912, and 0.7611 (sensitivity 63.3%, specificity 83.3%) for cg00103771. The diagnostic accuracy of the combination of these 3 indicators presented to be higher than any single one of them, with an AUC of 0.8378 (sensitivity 73.3%, specificity 93.3%).

CONCLUSION

The combination of 3 CpG methylation signatures in blood was identified with a good diagnostic accuracy for PCOS, which may bring new insight into the development of PCOS diagnostic markers in the future.

Single nucleus multi-omics regulatory landscape of the murine pituitary

To provide a multi-omics resource and investigate transcriptional regulatory mechanisms, we profile the transcriptome, chromatin accessibility, and methylation status of over 70,000 single nuclei (sn) from adult mouse pituitaries. Paired snRNAseq and snATACseq datasets from individual animals highlight a continuum between developmental epigenetically-encoded cell types and transcriptionally-determined transient cell states. Co-accessibility analysis-based identification of a putative Fshb cis-regulatory domain that overlaps the fertility-linked rs11031006 human polymorphism, followed by experimental validation illustrate the use of this resource for hypothesis generation. We also identify transcriptional and chromatin accessibility programs distinguishing each major cell type. Regulons, which are co-regulated gene sets sharing binding sites for a common transcription factor driver, recapitulate cell type clustering. We identify both cell type-specific and sex-specific regulons that are highly correlated with promoter accessibility, but not with methylation state, supporting the centrality of chromatin accessibility in shaping cell-defining transcriptional programs. The sn multi-omics atlas is accessible at snpituitaryatlas.princeton.edu.

Polycystic Ovary Syndrome: the Epigenetics Behind the Disease

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, affecting approximately 5-20% of women of reproductive age. PCOS is a multifactorial, complex, and heterogeneous disease, characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries, which may lead to impaired fertility. Besides the reproductive outcomes, multiple comorbidities, such as metabolic disturbances, insulin resistance, obesity, diabetes, and cardiovascular disease, are associated with PCOS. In addition to the clear genetic basis, epigenetic alterations may also play a central role in PCOS outcomes, as environmental and hormonal alterations directly affect clinical manifestations and PCOS development. Here, we highlighted the epigenetic modifications in the multiplicity of clinical manifestations, as well as environmental epigenetic disruptors, as intrauterine hormonal and metabolic alterations affecting embryo development and the adulthood lifestyle, which may contribute to PCOS development. Additionally, we also discussed the new approaches for future studies and potential epigenetic biomarkers for the treatment of associated comorbidities and improvement in quality of life of women with PCOS.

Variation analysis of anti-Müllerian hormone gene in Chinese women with polycystic ovary syndrome

PURPOSE

Anti-Müllerian hormone (AMH) is crucial for folliculogenesis. Prenatal exposure to AMH in mice produces a phenocopy of polycystic ovary syndrome (PCOS) in the adult female offspring. The aim of this study was to determine whether genetic variation in AMH gene contribute to PCOS in women of Chinese ancestry.

METHODS

We conducted a case-control genetic study in 383 PCOS case and 433 control women of Chinese ancestry. The exons and the 5' flanking region of AMH were sanger sequenced. Bioinformatic prediction of variant deleteriousness was performed.

RESULTS

Seven novel heterozygous variants along with 15 rare known variants in AMH were identified in women with PCOS but not in controls. The novel variants included one frameshift variant (c.125_129delACTTG), one synonymous variant (c.1095C>T), one variant (c.-14T>C) in the 5'-untranslated region (UTR), four variants(c.-775C>T, c.-682C>T, c.-333A>G, c.-137A>T) in 5' flanking sequence. Of all the AMH variants identified in women with PCOS, eight were predicted to be deleterious by bioinformatic analysis. The PCOS carriers of predicted-to-be-deleterious PCOS-specific AMH variants had increased total follicle numbers compared to PCOS noncarriers (p = 0.021).

CONCLUSIONS

Our findings suggest the AMH plays a role in the development of PCOS. The exact mechanisms by which the predicted-to-be-deleterious novel and rare AMH variants described in our study affect AMH function requires further study.

Assessment of Bidirectional Relationships Between Polycystic Ovary Syndrome and Periodontitis: Insights From a Mendelian Randomization Analysis

Background

Observational studies have indicated an association between polycystic ovary syndrome (PCOS) and periodontitis, but it is unclear whether the association is cofounded or causal. We conducted a two-sample Mendelian randomization (MR) study to investigate the bidirectional relationship between genetically predicted PCOS and periodontitis.

Methods

From two genome-wide association studies we selected 13 and 7 single nucleotide polymorphisms associated with PCOS and periodontitis, respectively, as instrumental variables. We utilized publicly shared summary-level statistics from European-ancestry cohorts. To explore the causal effect of PCOS on periodontitis, 12,289 cases of periodontitis and 22,326 controls were incorporated, while 4,890 cases of PCOS and 20,405 controls in the reverse MR. Inverse-variance weighted method was employed in the primary MR analysis and multiple sensitivity analyses were implemented.

Results

Genetically determined PCOS was not causally associated with risk of periodontitis (odds ratio 0.97; 95% confidence interval 0.88-1.06; P = 0.50) per one-unit increase in the log-odds ratio of periodontitis. Similarly, no causal effect of periodontitis on PCOS was shown with the odds ratio for PCOS was 1.17 (95% confidence interval 0.91-1.49; P = 0.21) per one-unit increase in the log-odds ratio of periodontitis. Consistent results were yielded via additional MR methods. Sensitivity analyses demonstrated no presence of horizontal pleiotropy or heterogeneity.

Conclusion

The bidirectional MR study couldn't provide convincing evidence for the causal relationship between genetic liability to PCOS and periodontitis in the Europeans. Triangulating evidence across further observational and genetic-epidemiological studies is necessary.

Whole-Genome Sequencing and Characterization of Buffalo Genetic Resources: Recent Advances and Future Challenges

The buffalo was domesticated around 3000-6000 years ago and has substantial economic significance as a meat, dairy, and draught animal. The buffalo has remained underutilized in terms of the development of a well-annotated and assembled reference genome de novo. It is mandatory to explore the genetic architecture of a species to understand the biology that helps to manage its genetic variability, which is ultimately used for selective breeding and genomic selection. Morphological and molecular data have revealed that the swamp buffalo population has strong geographical genomic diversity with low gene flow but strong phenotypic consistency, while the river buffalo population has higher phenotypic diversity with a weak phylogeographic structure. The availability of recent high-quality reference genome and genotyping marker panels has invigorated many genome-based studies on evolutionary history, genetic diversity, functional elements, and performance traits. The increasing molecular knowledge syndicate with selective breeding should pave the way for genetic improvement in the climatic resilience, disease resistance, and production performance of water buffalo populations globally.

Perceptions and experiences of lifestyle interventions in women with polycystic ovary syndrome (PCOS), as a management strategy for symptoms of PCOS

BACKGROUND

The international clinical practice guidelines for PCOS emphasize diet and exercise as first-line management of clinical signs and symptoms. This study aimed to describe the patterns, perceptions and experiences of lifestyle interventions for women in the community with PCOS.

METHOD

An electronic survey of 493 members of two PCOS consumer support groups, collected by cloud-based Survey Monkey, described women's types and patterns of diet and exercise, experiences and perceptions of effectiveness. Women were recruited from the Polycystic Ovary Association of Australia (POSAA) and from the Facebook group, PCOS University Research Group. Associations between participants perceptions of effectiveness, and diet types and exercise patterns were assessed using logistic regression. Response bias for the POSAA group was assessed with a continuum of resistance model.

RESULTS

91% of POSAA members and 311 Facebook group members aged 16-50 years responded to the survey. Nearly all women reported adjusting their dietary and exercise practices with the aim to improve their health and/or PCOS (82% and 73% respectively), however less than 13% reported achievement of health goals (12.2% and 8.1% respectively). Low carbohydrate, high protein diets, and vigorous activity were associated with self-perceived effectiveness (r.0.16, p < 0.01; r.0.15 p < 0.01 and r.0.2 p < 0.01 respectively). Barriers for lifestyle interventions included psychosocial factors. Response bias was not assessed for the Facebook group, however self-reported PCOS aligned with prevalence of clinical phenotypes and suggests results are generalizable to clinical populations of women with PCOS, who are responsible for self-directing and administering lifestyle interventions to manage their PCOS.

CONCLUSIONS

Perceptions of effectiveness for lifestyle interventions by women with PCOS may be complicated by a lack of rigorous evidence. The strength of recommendations in clinical practice guidelines may be enhanced by clinical trials investigating flexible and feasible lifestyle interventions for women in the community with PCOS.