A guide to understanding polycystic ovary syndrome (PCOS)

Development of an acute ovine model of polycystic ovaries to assess the effect of ovarian denervation

Introduction

Polycystic ovary syndrome (PCOS) seems to be associated with increased ovarian sympathetic nerve activity and in rodent models of PCOS reducing the sympathetic drive to the ovary, through denervation or neuromodulation, improves ovulation rate. We hypothesised that sympathetic nerves work with gonadotropins to promote development and survival of small antral follicles to develop a polycystic ovary phenotype.

Methods

Using a clinically realistic ovine model we showed a rich sympathetic innervation to the normal ovary and reinnervation after ovarian transplantation. Using needlepoint diathermy to the nerve plexus in the ovarian vascular pedicle we were able to denervate the ovary resulting in reduced intraovarian noradrenaline and tyrosine hydroxylase immunostained sympathetic nerves. We developed an acute polycystic ovary (PCO) model using gonadotrophin releasing hormone (GnRH) agonist followed infusion of follicle stimulating hormone (FSH) with increased pulsatile luteinising hormone (LH). This resulted in increased numbers of smaller antral follicles in the ovary when compared to FSH infusion suggesting a polycystic ovary.

Results

Denervation had no effect of the survival or numbers of follicles in the acute PCO model and did not impact on ovulation, follicular and luteal hormone profiles in a normal cycle.

Discussion

Although the ovary is richly inervated we did not find evidence for a role of sympathetic nerves in ovarian function or small follicle growth and survival.

Subfertility as Overlapping of Nutritional, Endocrine, Immune, and Cardiometabolic Dysregulations-A Study Focused on Biochemical Endophenotypes of Subfertile Couples

Subfertility is a global health issue, and as many as 30% of cases are attributed to unexplained reasons. A hypercaloric, high-fat diet stimulates the expansion of pro-inflammatory gut microbiota with a consequent rise in circulating lipopolysaccharides. Adverse gut microbiota remodeling can exacerbate insulin resistance, while sex and thyroid hormones may influence the variability in gut microbiota. This cross-sectional study included 150 participants and was designed to determine a biochemical, nutritional-related pattern that may distinguish subfertile from fertile individuals and couples. A panel of 28 biomarkers was assessed. Four biochemical phenotypes of unexplained subfertility were found, including two metabolic and two immune, when assessed using binary logistic regression models. Two phenotypes were distinguished in women: cardio-metabolic with atherogenic dyslipidemia (LowHDL-cholesterol: OR = 10.9; p < 0.05) and autoimmune thyroid disorder (Highanti-thyroid-peroxidase: OR = 5.5; p < 0.05) and two in men: hepato-metabolic with elevated liver injury enzymes (HighHOMA-IR: OR = 6.1; p < 0.05) and immune type-2 response (HighIgE: OR = 6.4; p < 0.05). The chances of a couple's subfertility rose with the number of laboratory components of metabolic syndrome in the couple (OR = 1.7; p < 0.05) and if at least one partner had an elevated total IgE level (>100 kU/L) (OR = 6.5; p < 0.05). This study found that unexplained subfertility may be accompanied by mutually overlapping immune and metabolic dysregulations in individuals and couples. We propose one-time laboratory diagnostics taking into account the lipid profile, insulin resistance, anti-thyroid-peroxidase, and total IgE in both males and females with unexplained subfertility. This may allow for a one-time assessment of targeted medical and nutritional interventions and help optimize patients' health. The gut-organ axes related to subfertility are discussed in the context of the obtained results.

Beyond apoptosis: evidence of other regulated cell death pathways in the ovary throughout development and life

BACKGROUND

Regulated cell death is a fundamental component of numerous physiological processes; spanning from organogenesis in utero, to normal cell turnover during adulthood, as well as the elimination of infected or damaged cells throughout life. Quality control through regulation of cell death pathways is particularly important in the germline, which is responsible for the generation of offspring. Women are born with their entire supply of germ cells, housed in functional units known as follicles. Follicles contain an oocyte, as well as specialized somatic granulosa cells essential for oocyte survival. Follicle loss-via regulated cell death-occurs throughout follicle development and life, and can be accelerated following exposure to various environmental and lifestyle factors. It is thought that the elimination of damaged follicles is necessary to ensure that only the best quality oocytes are available for reproduction.

OBJECTIVE AND RATIONALE

Understanding the precise factors involved in triggering and executing follicle death is crucial to uncovering how follicle endowment is initially determined, as well as how follicle number is maintained throughout puberty, reproductive life, and ovarian ageing in women. Apoptosis is established as essential for ovarian homeostasis at all stages of development and life. However, involvement of other cell death pathways in the ovary is less established. This review aims to summarize the most recent literature on cell death regulators in the ovary, with a particular focus on non-apoptotic pathways and their functions throughout the discrete stages of ovarian development and reproductive life.

SEARCH METHODS

Comprehensive literature searches were carried out using PubMed and Google Scholar for human, animal, and cellular studies published until August 2022 using the following search terms: oogenesis, follicle formation, follicle atresia, oocyte loss, oocyte apoptosis, regulated cell death in the ovary, non-apoptotic cell death in the ovary, premature ovarian insufficiency, primordial follicles, oocyte quality control, granulosa cell death, autophagy in the ovary, autophagy in oocytes, necroptosis in the ovary, necroptosis in oocytes, pyroptosis in the ovary, pyroptosis in oocytes, parthanatos in the ovary, and parthanatos in oocytes.

OUTCOMES

Numerous regulated cell death pathways operate in mammalian cells, including apoptosis, autophagic cell death, necroptosis, and pyroptosis. However, our understanding of the distinct cell death mediators in each ovarian cell type and follicle class across the different stages of life remains the source of ongoing investigation. Here, we highlight recent evidence for the contribution of non-apoptotic pathways to ovarian development and function. In particular, we discuss the involvement of autophagy during follicle formation and the role of autophagic cell death, necroptosis, pyroptosis, and parthanatos during follicle atresia, particularly in response to physiological stressors (e.g. oxidative stress).

WIDER IMPLICATIONS

Improved knowledge of the roles of each regulated cell death pathway in the ovary is vital for understanding ovarian development, as well as maintenance of ovarian function throughout the lifespan. This information is pertinent not only to our understanding of endocrine health, reproductive health, and fertility in women but also to enable identification of novel fertility preservation targets.

Therapeutic Effects and Molecular Mechanism of Chlorogenic Acid on Polycystic Ovarian Syndrome: Role of HIF-1alpha

Chlorogenic acid (CGA) is a powerful antioxidant polyphenol molecule found in many diets and liquid beverages, playing a preventive and therapeutic role in various diseases caused by oxidative stress and inflammation. Recent research has found that CGA can not only improve clinical symptoms in PCOS patients but also improve follicular development, hormone status, and oxidative stress in PCOS rats, indicating the therapeutic effect of CGA on PCOS. Notably, our previous series of studies has demonstrated the expression changes and regulatory mechanisms of HIF-1alpha signaling in PCOS ovaries. Considering the regulatory effect of CGA on the HIF-1alpha pathway, the present article systematically elucidates the therapeutic role and molecular mechanisms of HIF-1alpha signaling during the treatment of PCOS by CGA, including follicular development, steroid synthesis, inflammatory response, oxidative stress, and insulin resistance, in order to further understand the mechanisms of CGA effects in different types of diseases and to provide a theoretical basis for further promoting CGA-rich diets and beverages simultaneously.

Molecular characterization of extracellular vesicles derived from follicular fluid of women with and without PCOS: integrating analysis of differential miRNAs and proteins reveals vital molecules involving in PCOS

PURPOSE

To elucidate the characterization of extracellular vesicles (EVs) in the follicular fluid-derived extracellular vesicles (FF-EVs) and discover critical molecules and signaling pathways associating with the etiology and pathobiology of PCOS, the differentially expressed miRNAs (DEmiRNAs) and differentially expressed proteins profiles (DEPs) were initially explored and combinedly analyzed.

METHODS

First, the miRNA and protein expression profiles of FF-EVs in PCOS patients and control patients were compared by RNA-sequencing and tandem mass tagging (TMT) proteomic methods. Subsequently, Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes were used to analyze the biological function of target genes of DEmiRNAs and DEPs. Finally, to discover the functional miRNA-target gene-protein interaction pairs involved in PCOS, DEmiRs target gene datasets and DEPs datasets were used integratedly.

RESULTS

A total of 6 DEmiRNAs and 32 DEPs were identified in FF-EVs in patients with PCOS. Bioinformatics analysis revealed that DEmiRNAs target genes are mainly involved in thiamine metabolism, insulin secretion, GnRH, and Apelin signaling pathway, which are closely related to the occurrence of PCOS. DEPs also closely related to hormone metabolism processes such as steroid hormone biosynthesis. In the analysis integrating DEmiRNAs target genes and DEPs, two molecules, GRAMD1B and STPLC2, attracted our attention that are closely associated with cholesterol transport and ceramide biosynthesis, respectively.

CONCLUSION

Dysregulated miRNAs and proteins in FF-EVs, mainly involving in hormone metabolism, insulin secretion, neurotransmitters regulation, adipokine expression, and secretion, may be closely related to PCOS. The effects of GRAMD1B and STPLC2 on PCOS deserve further study.

Plasma Complement C1q/tumor necrosis factor-related protein 15 concentration is associated with polycystic ovary syndrome

Polycystic ovarian syndrome (PCOS) is a common poignant endocrine disorder affecting women, posing a close association with metabolic syndrome and obesity. Existing literature characterizes PCOS with deranged levels of several adipokines and myokines. CTRP15 is a paralogue of adiponectin, mainly expressed by skeletal muscles, and plays a key role in insulin, glucose, and lipid metabolism. In the current study, we aim to determine the circulating levels of CTRP15 and evaluate its association with cardiometabolic and inflammatory parameters in PCOS women. This case-control study included 120 PCOS patients (60 Recurrent pregnancy loss (RPL) and 60 infertile (inf) PCOS) and 60 healthy non-PCOS controls. Serum levels of hs-CRP were measured by commercial kits, while serum levels of adiponectin and CTRP15 were determined using the ELISA technique. Serum levels of CTRP15 were significantly elevated in PCOS-RPL and PCOS-inf subgroups when compared to controls (94.80 ± 27.08 and 87.77 ± 25.48 vs. 54.78 ± 15.45, both P < 0.001). Moreover, serum adiponectin was considerably lower in the PCOS group and subgroups (P < 0.001), while serum hs-CRP, fasting insulin, HOMA-IR, and free testosterone were significantly higher when compared to the non-PCOS group (P < 0.05). Furthermore, CTRP15 closely associated with FSH, HOMA-IR, hs-CRP, and BMI. These results highlight a possible involvement of CTRP15 in the pathogenesis of PCOS. The elevated levels of CTRP15 might be a compensatory mechanism for the metabolic dysregulations (excess adiposity, insulin resistance, metaflammation) associated with the syndrome. Nevertheless, future studies are necessary to unravel the underlying mechanism.

Review of human genetic and clinical studies directly relevant to GnRH signalling

GnRH is the pivotal hormone in controlling the hypothalamic-pituitary gonadal (HPG) axis in humans and other mammalian species. GnRH function is influenced by a multitude of known and still unknown environmental and genetic factors. Molecular genetic studies on human families with hypogonadotropic hypogonadism over the past two decades have been instrumental in delineating the kisspeptin and neurokinin B signalling, which integrally modulates GnRH release from the hypothalamus. The identification of kisspeptin and neurokinin B ligand-receptor gene pair mutations in patients with absent puberty have paved the way to a greater understanding of the central regulation of the HPG cascade. In this article, we aim to review the literature on the genetic and clinical aspects of GnRH and its receptor, as well as the two ligand-receptor sets directly pertinent to the function of GnRH hormone signalling, kisspeptin/ kisspeptin receptor and NKB/NK3R.

The single-nucleotide polymorphism rs743572 of CYP17A1 shows significant association with polycystic ovary syndrome: a meta-analysis

Polycystic ovary syndrome (PCOS) is a multifactorial reproductive and endocrine disease, believed to be caused by aberrant steroid biosynthesis pathways involving cytochrome P450, 17α-hydroxylase (CYP17A1). This meta-analysis aimed to evaluate the association between CYP17A1 polymorphism rs743572 and PCOS risk. Studies on the CYP17A1 gene were retrieved by searching PubMed, Embase and Web of Science and statistical analyses were performed by STATA software. Fifteen eligible studies were included, dated from January 1994 to 19 November 2020, involving 2277 patients with PCOS and 1913 control individuals. Overall, the results showed that the rs743572 T>C mutation was most likely to be associated with PCOS risk under the recessive model, which was further confirmed by heterogeneity analysis and publication bias detection (CC versus CT + TT, odds ratio [OR] 1.24, 95% confidence interval [CI] 1.02-1.50, P = 0.028, I² = 35.9%). Moreover, subgroup analysis by ethnicity demonstrated that Caucasian but not Asian women carrying the CC genotype of rs743572 had an elevated risk of PCOS (CC versus CT + TT, OR 1.45, 95% CI 1.03-2.06, P = 0.035, I² = 15.10%, six studies). In conclusion, rs743572 is highly likely to be a risk factor for PCOS, and the mutant genotype CC may increase susceptibility to PCOS in Caucasians rather than Asians.

Randomized Controlled Trial of Neurokinin 3 Receptor Antagonist Fezolinetant for Treatment of Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS), a highly prevalent endocrine disorder characterized by hyperandrogenism, is the leading cause of anovulatory infertility.

OBJECTIVE

This proof-of-concept study evaluated clinical efficacy and safety of the neurokinin 3 (NK3) receptor antagonist fezolinetant in PCOS.

METHODS

This was a phase 2a, randomized, double-blind, placebo-controlled, multicenter study (EudraCT 2014-004409-34). The study was conducted at 5 European clinical centers. Women with PCOS participated in the study. Interventions included fezolinetant 60 or 180 mg/day or placebo for 12 weeks. The primary efficacy end point was change in total testosterone. Gonadotropins, ovarian hormones, safety and tolerability were also assessed.

RESULTS

Seventy-three women were randomly assigned, and 64 participants completed the study. Adjusted mean (SE) changes in total testosterone from baseline to week 12 for fezolinetant 180 and 60 mg/day were -0.80 (0.13) and -0.39 (0.12) nmol/L vs -0.05 (0.10) nmol/L with placebo (P < .001 and P < .05, respectively). Adjusted mean (SE) changes from baseline in luteinizing hormone (LH) for fezolinetant 180 and 60 mg/d were -10.17 (1.28) and -8.21 (1.18) vs -3.16 (1.04) IU/L with placebo (P < .001 and P = .002); corresponding changes in follicle-stimulating hormone (FSH) were -1.46 (0.32) and -0.92 (0.30) vs -0.57 (0.26) IU/L (P = .03 and P = .38), underpinning a dose-dependent decrease in the LH-to-FSH ratio vs placebo (P < .001). Circulating levels of progesterone and estradiol did not change significantly vs placebo (P > .10). Fezolinetant was well tolerated.

CONCLUSION

Fezolinetant had a sustained effect to suppress hyperandrogenism and reduce the LH-to-FSH ratio in women with PCOS.

Correlation between leptin and IFN-γ involved in granulosa cell apoptosis in PCOS

OBJECTIVES

Our study aimed to explore the relationship between leptin and IFN-γ in PCOS patients, and confirmed the effect of leptin-induced IFN-γ on granulosa cells furtherly.

METHODS

29 patients with PCOS and 36 healthy controls were enrolled. Leptin level and the proportion of Th1 cells were detected and association between them were analyzed. Meanwhile, peripheral blood mononuclear cells (PBMCs) isolated from PCOS patients were treated with leptin and then the proportion of Th1 was analyzed. Besides that, the apoptotic level of KGN cells was monitored after IFN-γ treatment.

RESULTS

In the circulation of PCOS patients, leptin level dramatically increased compared with controls. And, this was associated with upregulated Th1 cells proportion and IFN-γ level. In vitro, Th1 cells proportion increased after leptin treated PBMCs from PCOS patients. Furthermore, for KGN cells, the percentage of live cells decreased and later apoptosis cells increased after IFN-γ treatment.

CONCLUSIONS

Our results indicated that leptin takes part in process of PCOS via inducing expression of IFN-γ. Our findings highlight the importance of the connection between leptin and inflammation in PCOS and provide new insights therapeutic strategy for this disease.

The Relationship Between Polycystic Ovarian Syndrome, Periodontal Disease, and Osteoporosis

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder to affect women in their reproductive years. There has been growing concern that women with PCOS may suffer from long-term metabolic consequences due to the high degree of insulin resistance that is often present in PCOS. However, few longitudinal studies exist in this area and there is a paucity of data on whether women with PCOS are at risk of other chronic diseases as they age. Specifically, current evidence suggests that reproductive-age women with PCOS may be at increased risk for both osteoporosis and periodontal disease (PD)-both these chronic diseases can have serious implications for health and quality of life. However, few studies have addressed how risk factors for osteoporosis and PD may be altered by aging in PCOS. The PCOS phenotype of women beyond reproductive years is poorly understood, and it is not known whether the metabolic profile of older women with PCOS results in an increased risk of osteoporosis and PD. The objective of this review is to discuss the relationships between PCOS, osteoporosis, and PD, and how these relationships could be impacted during aging. The long-term goal of this review is to provide direction for future research that is needed to more clearly elucidate these relationships and eventually provide a basis for evidence-based health recommendations.

S100-A9 protein in exosomes derived from follicular fluid promotes inflammation via activation of NF-κB pathway in polycystic ovary syndrome

Exosomes have recently emerged as key mediators of different physiological and pathological processes. However, there has been few report about proteomic analysis of exosomes derived from human follicular fluid and their association with the occurrence of PCOS. Herein, we used TMT‐tagged quantitative proteomic approach to identify proteomic profiles in exosomes derived from follicular fluid of PCOS patients and healthy controls. We identified 662 proteins in exosomes derived from human ovarian follicular fluid. Eighty‐six differently expressed proteins (P < .05) were found between PCOS and healthy women. The alterations in the proteomic profile were related to the inflammation process, reactive oxygen species metabolic process, cell migration and proliferation. Importantly, we observed that follicular fluid exosomes contain S100 calcium‐binding protein A9 (S100‐A9) protein. Exosome‐enriched S100‐A9 significantly enhanced inflammation and disrupted steroidogenesis via activation of nuclear factor kappa B (NF‐κB) signalling pathway. These data demonstrate that exosomal proteins are differentially expressed in follicular fluid during disease process, and some proteins may play important roles in the regulation of granulosa cell function. These results highlight the importance of exosomes as extracellular communicators in ovarian follicular development.

The role of FSH and TGF-β superfamily in follicle atresia

Most of the mammalian follicles undergo a degenerative process called “follicle atresia”. Apoptosis of granulosa cells is the main characteristic of follicle atresia. Follicle stimulating hormone (FSH) and the transforming growth factor β (TGF-β) superfamily have important regulatory functions in this process. FSH activates protein kinase A and cooperating with insulin receptor substrates, it promotes the PI3K/Akt pathway which weakens apoptosis. Both Smad or non-Smad signaling of the transforming growth factor β superfamily seem to be related to follicle atresia, and the effect of several important family members on follicle atresia is concluded in this article. FSH and TGF-β are likely to mutually influence each other and what we have already known about the possible underlying molecular mechanism is also discussed below.

The efficacy of Tung's acupuncture for sex hormones in polycystic ovary syndrome: A randomized controlled trial

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common and heterogeneous endocrine disorder in reproductive-age women. Tung's acupuncture, a Traditional Chinese Medicine (TCM) treatment, is widely used for PCOS in East Asia, but evidence on its efficacy is rare. The aim of this RCT study was to examine whether the Tung's acupuncture could be a complementary treatment method for PCOS.

METHODS

A total of 60 PCOS patients were randomly assigned to a Tung's acupuncture group (n = 30) or a cyproterone acetate/ethinylestradiol (CPA/EE) group (n = 30). Each participant received treatments for 12 weeks to assess the short-term treatment efficacy and then followed up for another 12 weeks to assess the long-term treatment efficacy. The primary outcome examined was change in the ratio of luteinizing hormone (LH) to follicle-stimulating hormone (FSH); the secondary outcomes examined were changes in body mass index (BMI), LH, FSH, total testosterone (TT), ovarian volume, polycystic ovary number and menstrual frequency.

RESULTS

Both groups showed significant reductions in the LH/FSH ratio, LH and TT after 12-week treatment (p < 0.001) and 12-week follow-up (p < 0.05). No significant differences existed between the two groups (p > 0.05). Both groups showed significant improvement in BMI, menstrual frequency and polycystic ovary number after 12-week treatment (p < 0.05).

CONCLUSION

Compared with CPA/EE, Tung's acupuncture showed no better improvement on LH/FSH ratio for PCOS although it could reduce the ratio. Tung's acupuncture might have some effect on long-term weight control and menstruation frequency. Further studies addressing this study's limitations are recommended.

Effects of hypoxia‑inducible factor‑1α on endometrial receptivity of women with polycystic ovary syndrome

Embryo implantation is associated with an hypoxic endometrial microenvironment. Hypoxia‑inducible factor‑1α (HIF‑1α) is activated under hypoxic conditions. In the present study, the expression pattern of HIF‑1α in endometrial tissue was investigated and its effects on endometrial receptivity in patients with polycystic ovary syndrome (PCOS) were examined. A total of 81 patients were enrolled for in vitro fertilization and embryo transfer. They were divided into PCOS (n=40) and Control groups (n=41); both groups were further divided based on body weight (overweight and normal weight subgroups). The expressions of HIF‑1α, vascular endothelial growth factor (VEGF) and glucose transporter protein (GLUT)‑1 and GLUT4 were determined by reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry. The results demonstrated that mRNA and protein expression levels of HIF‑1α and VEGF in the PCOS group were significantly lower compared with expression levels in the Control group. However, there were no statistically significant differences in the expression levels of GLUT1 and GLUT4 between groups. In patients with PCOS, GLUT1 and GLUT4 were mainly localized in the nuclei and cytoplasm, but not in the cell membrane. Overweight patients had the lowest expression levels of HIF‑1α, VEGF and GLUT1 expression compared with normal weight patients. In conclusion, HIF‑1α may be involved in the molecular mechanisms of endometrial dysfunction in women with PCOS, particularly in those who are overweight. HIF‑1α might therefore be a novel target for improving the endometrial receptivity and successful embryo implantation in PCOS women.

Evaluation of serum hepcidin and iron levels in patients with PCOS: a case-control study

PURPOSE

Polycystic ovary syndrome (PCOS) is the most common cause of chronic anovulation with a prevalence of 5-10% in women of reproductive age. The etiology of this disease is not well known, and hepcidin is one of the factors affecting the pathogenesis of the disease. The aim of this study was to evaluate plasma levels of hepcidin in patients with PCOS and its correlation with serum iron level.

METHODS

In this case-control study, plasma levels of hepcidin, IL-6, and ferritin using ELISA method and serum iron levels using a spectrophotometric method were tested on 56 women with PCOS (case group) and 41 healthy subjects (control group). The results were analyzed using t test, General Linear Model, Binary logistic regression, and linear regression tests.

RESULTS

The mean hepcidin levels were 1.97 ± 0.53 and 2.40 ± 0.25 pg/ml in the case and control groups, respectively. The t-test results showed significant difference between the two groups (p = 0.0001). The mean serum iron levels were 72.89 ± 28.97 and 70.62 ± 31.18 g/dl in the case and control groups, respectively. The t test analysis indicated no significant difference between the two groups. The serum ferritin and iron levels had no significant relation with serum hepcidin level in two groups.

CONCLUSION

Despite the differences in the serum levels of hepcidin between the two groups, no significant relation was observed between serum iron levels and hepcidin level in this group of patients. This implies the need for more comprehensive studies on gene expression in hepcidin and iron pathways using real-time and Western techniques to investigate more precisely serum hepcidin level and its relationship with the factors mentioned.

Serum Macroelement and Microelement Concentrations in Patients with Polycystic Ovary Syndrome: a Cross-Sectional Study

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine diseases. However, its pathogenesis is unclear. We aim to explore the potential relationships between serum macroelements/microelements and PCOS. A total of 1137 women were involved in the current study. PCOS was defined according to ESHRE/ASRM, and complete blood samples were collected. Serum macroelements (calcium and magnesium) and microelements (copper, zinc, and iron) were assayed through atomic absorption spectrophotometry. PCOS patients had significantly higher copper concentrations than patients without PCOS (P < 0.001). By contrast, PCOS patients had lower serum calcium levels than patients without PCOS (P < 0.001). No significant differences were observed in the levels of serum zinc, magnesium, and iron between PCOS and non-PCOS patients. PCOS patients with acne had higher magnesium levels than those without acne (P = 0.020), and PCOS patients with hirsutism had lower magnesium levels than those without hirsutism (P = 0.037). High serum copper and low calcium levels may be correlated with PCOS. Magnesium concentrations are correlated with acne and hirsutism in PCOS patients. These results provide clues to explore the mechanism of PCOS and guidance for element treatments in PCOS patients.

Expression and clinical significance of the HIF-1a/ET-2 signaling pathway during the development and treatment of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a major health problem in reproductive-aged women worldwide, but the precise pathogenesis of PCOS remains unclear. Our previous study revealed that hypoxia-inducible factor (HIF)-1a mediated endothelin (ET)-2 signaling plays an important role in ovulation in rats. Therefore, the present study used a PCOS rat model to test the hypotheses that HIF-1a signaling is expressed and inhibited in ovaries during PCOS formation and that the HIF-1a/ET-2 signaling pathway is a target of dimethyldiguanide (DMBG) in the clinical treatment of PCOS. First, the development of a PCOS model and the effect of DMBG treatment were examined through ovarian histology and serum hormone levels, which were consistent with previous reports. Second, HIF-1a and ET-2 expression were detected by immunohistochemistry and western blot. The results showed decreased HIF-1a/ET-2 expression in the ovaries of PCOS rats, whereas DMBG treatment reversed the protein decreases and improved the PCOS symptoms. Third, to understand the molecular mechanism, HIF-1a/ET-2 mRNA expression was also examined. Interestingly, HIF-1a mRNA increased in the ovaries of PCOS rats, while ET-2 mRNA decreased, indicating that HIF-1a protein degradation may be involved in POCS development and treatment. Finally, HIF prolyl hydroxylase (PHD) activity was examined to further clarify the contribution of HIF-1a signaling to the development and treatment of PCOS. The results suggested that the inhibition of HIF-1a/ET-2 signaling may be caused by increased PHD activity in PCOS. DMBG-treated PCOS may further activate HIF-1a signaling at least partly through inhibiting PHD activity. Taken together, these results indicate that HIF-1a signaling is inhibited in a PCOS rat model through increasing PHD activity. DMBG treatment improved PCOS by rescuing this pathway, suggesting that HIF-1a signaling plays an important role in the development and treatment of PCOS. This HIF-1a-mediated ET-2 signaling pathway may be an important mechanism regulating PCOS formation and treatment in mammalian ovaries in vivo and should be a new clinical target for PCOS prevention and treatment in the future.