Abnormal GnRH Pulsatility in Polycystic Ovary Syndrome: Recent Insights.
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ABSTRACT:
SUBMITTER: McCartney CR
PROVIDER: S-EPMC7365617 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Objective:Is polycystic ovary syndrome (PCOS) associated with activating autoantibodies (AAb) to the second extracellular loop (ECL2) of gonadotropin-releasing hormone receptor (GnRHR)? Design and Methods:We retrospectively screened sera from 40 patients with PCOS and 14 normal controls (NCs) with regular menses using enzyme-linked immunosorbent assay (ELISA) for the presence of GnRHR-ECL2-AAb. We obtained similar data from 40 non-PCOS ovulatory but infertile patients as a control group (OIC) of interest. We analyzed GnRHR-ECL2-AAb activity in purified immunoglobulin (Ig)G using a cell-based GnRHR bioassay. Results:The mean ELISA value in the PCOS group was markedly higher than the NC (P?=?.000036) and the OIC (P?=?.0028) groups. IgG from a sample of 5 PCOS subjects, in contrast to a sample of 5 OIC subjects, demonstrated a dose-dependent increase in GnRHR-stimulating activity qualitatively similar to the acute action of the natural ligand GnRH and the synthetic agonist leuprolide. The GnRHR antagonist cetrorelix significantly suppressed (P?<?.01) the elevated GnRHR activity induced by IgG from 7 PCOS patients while the IgG activity level from 7 OIC subjects was unchanged. Five other OIC subjects had relatively high ELISA values at or above the 95% confidence limits. On further study, 3 had normal or low activity while 2 had elevated IgG-induced GnRHR activity. One suppressed with cetrorelix while the other did not. The copresence of PCOS IgG increased the responsiveness to GnRH and shifted the dosage response curve to the left (P?<?.01). Conclusions:GnRHR-ECL2-AAb are significantly elevated in patients with PCOS compared with NCs. Their presence raises important etiological, diagnostic, and therapeutic implications.
| S-EPMC7417878 | biostudies-literature
Project description:Infertility associated with obesity is characterized by abnormal hormone release from reproductive tissues in the hypothalamus, pituitary, and ovary. These tissues maintain insulin sensitivity upon peripheral insulin resistance. Insulin receptor signaling may play a role in the dysregulation of gonadotropin-releasing hormone (GnRH) secretion in obesity, but the interdependence of hormone secretion in the reproductive axis and the multi-hormone and tissue dysfunction in obesity hinders investigations of putative contributing factors to the disrupted GnRH secretion. To determine the role of GnRH insulin receptor signaling in the dysregulation of GnRH secretion in obesity, we created murine models of diet-induced obesity (DIO) with and without intact insulin signaling in the GnRH neuron. Obese control female mice were infertile with higher luteinizing hormone levels and higher GnRH pulse amplitude and total pulsatile secretion compared to lean control mice. In contrast, DIO mice with a GnRH specific knockout of insulin receptor had improved fertility, luteinizing hormone levels approaching lean mice, and GnRH pulse amplitude and total secretion similar to lean mice. Pituitary responsiveness was similar between genotypes. These results suggest that in the obese state, insulin receptor signaling in GnRH neurons increases GnRH pulsatile secretion and consequent LH secretion, contributing to reproductive dysfunction.
| S-EPMC4363364 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Epidemiological findings revealed that women with PCOS are prone to develop certain cancer types due to their shared metabolic and endocrine abnormalities. However, the mechanism that relates PCOS and oncogenesis has not been addressed. Herein, in this review article the genomic status, transcriptional and protein profiles of 264 strongly PCOS related genes (PRG) were evaluated in endometrial cancer (EC), ovarian cancer (OV) and breast cancer (BC) exploring oncogenic databases. The genomic alterations of PRG were significantly higher when compared with a set of non-diseases genes in all cancer types. PTEN had the highest number of mutations in EC, TP53, in OC, and FSHR, in BC. Based on clinical data, women older than 50 years and Black or African American females carried the highest ratio of genomic alterations among all cancer types. The most altered signaling pathways were p53 in EC and OC, while Fc epsilon RI in BC. After evaluating PRG in normal and cancer tissue, downregulation of the differentially expressed genes was a common feature. Less than 30 proteins were up and downregulated in all cancer contexts. We identified 36 highly altered genes, among them 10 were shared between the three cancer types analyzed, which are involved in the cell proliferation regulation, response to hormone and to endogenous stimulus. Despite limited PCOS pharmacogenomics studies, 10 SNPs are reported to be associated with drug response. All were missense mutations, except for rs8111699, an intronic variant characterized as a regulatory element and presumably binding site for transcription factors. In conclusion, in silico analysis revealed key genes that might participate in PCOS and oncogenesis, which could aid in early cancer diagnosis. Pharmacogenomics efforts have implicated SNPs in drug response, yet still remain to be found.
| S-EPMC7729301 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, oligo- or anovulation, and/or polycystic ovary. It frequently presents with dyslipidemia and insulin resistance. Recent studies have shown that the white adipose tissue-derived asprosin is elevated in humans with insulin resistance. Because many PCOS patients have a propensity to develop dyslipidemia and/or insulin resistance, asprosin metabolism could be dysregulated in PCOS patients. Accordingly, we investigated serum levels of asprosin, irisin, GIP, androgens, LH, glucose, insulin, and lipids as well as HOMA-IR, QUICKI and ISI Matsuda in a cohort of 444 PCOS patients and 156 controls. Patients were stratified based on metabolic syndrome risk factors (ATPIII [+] and [-] groups), or BMI (overweight and lean groups). The irisin level was significantly correlated with body weight, SBP, DBP, Ferriman-Gallwey score, and levels of TSH, triglycerides, glucose and insulin in the overall population, and was elevated in ATPIII(+) and overweight PCOS patients compared to corresponding controls. By contrast, asprosin levels in PCOS, ATPIII(+), or overweight patients were similar to those of corresponding controls. This finding indicated that the regulation of irisin, but not asprosin, metabolism is abnormal in PCOS patients, and this metabolic characteristic is distinctly different from that of diabetes patients.
| S-EPMC6558936 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in women of fertile age. Obesity is encountered in 30-70% of PCOS-affected women, and its presence significantly modifies both clinical and laboratory expression of the syndrome. Obesity increases the risk of co-morbidities associated with PCOS, such as impaired glucose tolerance and type 2 diabetes mellitus, hyperlipidemia and arterial hypertension. The etiopathogenesis of obesity in PCOS has not yet been exactly clarified. There clearly is a vicious circle of abdominal obesity, insulin resistance, and hyperadrogenemia. Differences in ghrelin and neuropeptide Y levels between PCOS patients and those with simple obesity were also described. Weight loss is the first choice recommendation for the treatment of clinical manifestations of PCOS, such as menstrual cycle irregularities, infertility or hirsutism. However, the best treatment approach in obese PCOS patients remains to be defined. Studies concerning different weight loss regimens, antiobesity drugs, bariatric surgery, insulin sensitizers, and hormonal therapy are reviewed.
| S-EPMC6444522 | biostudies-literature
Project description:The etiology of polycystic ovary syndrome (PCOS) has been difficult to determine because its features are heterogeneous, and its origin may also be heterogeneous. Twin studies suggest that its etiology is strongly heritable and genetic approaches are rapidly uncovering new regions of the genome that appear to confer risk for PCOS. Recent genome-wide association studies in Han Chinese women with PCOS demonstrate 11 genetic loci that are associated with PCOS. The variants identified are in regions that contain genes important for gonadotropin action, genes that are associated with risk for type 2 diabetes, and other genes in which the relationship to PCOS is not yet clear. Replication studies have demonstrated that variants at several of these loci also confer risk for PCOS in women of European ethnicity. The strongest loci in Europeans contain genes for DENND1A and THADA, with additional associations in loci containing the LHCGR and FSHR, YAP1 and RAB5/SUOX. The next steps in uncovering the pathophysiology borne out by these loci and variants will include mapping to determine the causal variant and gene, phenotype studies to determine whether these regions are associated with particular features of PCOS and functional studies of the causal variant to determine the direct cause of PCOS based on the underlying genetics. The next years will be very exciting times as groups from around the world come together to further elucidate the genetic origins of PCOS.
| S-EPMC4066994 | biostudies-literature
Project description:PurposeWe have recently demonstrated that gonadotrophin-releasing hormone receptor-activating autoantibodies (GnRHR-AAb) are associated with polycystic ovary syndrome (PCOS). The aim of this study was to map the antigenic epitopes of GnRHR-AAb from PCOS patients, and develop retro-inverso peptide inhibitors that specifically target GnRHR-AAb.MethodsSerum samples from ten GnRHR-AAb-positive PCOS patients and ten GnRHR-AAb-negative healthy controls were tested. Epitope mapping for GnRHR-AAb was performed using a set of 11 overlapping octapeptides spanning the second extracellular loop of GnRHR. Antibody-blocking effect of the designed retro-inverso peptide inhibitors was evaluated in a cell-based bioassay.ResultsTwo peptide sequences, FSQCVTHC and HCSFSQWW, were found to react with all PCOS sera, but not with control sera. Two retro-inverso peptides that mimic the identified epitopes, d-CHTVCQSF and d-WWQSFSCH, significantly inhibited PCOS serum IgG-induced GnRHR activation. One of these two peptide inhibitors, d-CHTVCQSF, largely suppressed autoantibody-induced GnRHR activation, suggesting that the epitope sequence FSQCVTHC may be a major functional target of GnRHR-AAb.ConclusionWe have identified a dominant functional epitope for GnRHR-AAb associated with PCOS, and demonstrated effective blocking of GnRHR-AAb activity with epitope-mimicking retro-inverso peptide inhibitors. These proteolytically stable decoy peptides may have important therapeutic implications in subjects who harbor these autoantibodies.
| S-EPMC8891032 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a highly complex endocrine disorder, characterized by hyperandrogenemia, menstrual irregularities and polycystic ovaries. A strong genetic component to the etiology of PCOS is evident. However, due to the genetic and phenotypic heterogeneity of PCOS and the lack of insufficiently large cohorts, studies to identify specific contributing genes to date have yielded only few conclusive results. In this review we discuss the current status of the genetic analysis of PCOS including the results of numerous association studies with candidate genes involved in TGF-β and insulin signaling, type 2 diabetes mellitus and obesity susceptibility. Furthermore, we address current challenges in genetic studies of PCOS, and the promise of new approaches, including genome-wide association studies and next-generation sequencing.
| S-EPMC3609918 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects up to 6.8% of reproductive age women. Experimental research and clinical observations suggest that PCOS may originate in the very early stages of development, possibly even during intrauterine life. This suggests that PCOS is either genetically-transmitted or is due to epigenetic alterations that develop in the intrauterine microenvironment. Although familial cases support the role of genetic factors, no specific genetic pattern has been defined in PCOS. Several candidate genes have been implicated in its pathogenesis, but none can specifically be implicated in PCOS development. Hypotheses based on the impact of the intrauterine environment on PCOS development can be grouped into two categories. The first is the "thrifty" phenotype hypothesis, which states that intrauterine nutritional restriction in fetuses causes decreased insulin secretion and, as a compensatory mechanism, insulin resistance. Additionally, an impaired nutritional environment can affect the methylation of some specific genes, which can also trigger PCOS. The second hypothesis postulates that fetal exposure to excess androgen can induce changes in differentiating tissues, causing the PCOS phenotype to develop in adult life. This review aimed to examine the role of fetal programming in development of PCOS.
| S-EPMC4499527 | biostudies-literature
Project description:Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder of premenopausal women worldwide and is characterized by reproductive, endocrine, and metabolic abnormalities. The clinical manifestations of PCOS include oligomenorrhea or amenorrhea, hyperandrogenism, ovarian polycystic changes, and infertility. Women with PCOS are at an increased risk of suffering from type 2 diabetes; me\tabolic syndrome; cardiovascular events, such as hypertension, dyslipidemia; gynecological diseases, including infertility, endometrial dysplasia, endometrial cancer, and ovarian malignant tumors; pregnancy complications, such as premature birth, low birthweight, and eclampsia; and emotional and mental disorders in the future. Although numerous studies have focused on PCOS, the underlying pathophysiological mechanisms of this disease remain unclear. Mitochondria play a key role in energy production, and mitochondrial dysfunction at the cellular level can affect systemic metabolic balance. The recent wide acceptance of functional mitochondrial disorders as a correlated factor of numerous diseases has led to the presupposition that abnormal mitochondrial metabolic markers are associated with PCOS. Studies conducted in the past few years have confirmed that increased oxidative stress is associated with the progression and related complications of PCOS and have proven the relationship between other mitochondrial dysfunctions and PCOS. Thus, this review aims to summarize and discuss previous and recent findings concerning the relationship between mitochondrial dysfunction and PCOS.
| S-EPMC6698037 | biostudies-literature