Identification of differentially expressed microRNAs in the ovary of polycystic ovary syndrome with hyperandrogenism and insulin resistance

miRNA expression in PCOS: unveiling a paradigm shift toward biomarker discovery

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that affects a substantial percentage of women, estimated at around 9-21%. This condition can lead to anovulatory infertility in women of childbearing age and is often accompanied by various metabolic disturbances, including hyperandrogenism, insulin resistance, obesity, type-2 diabetes, and elevated cholesterol levels. The development of PCOS is influenced by a combination of epigenetic alterations, genetic mutations, and changes in the expression of non-coding RNAs, particularly microRNAs (miRNAs). MicroRNAs, commonly referred to as non-coding RNAs, are approximately 22 nucleotides in length and primarily function in post-transcriptional gene regulation, facilitating mRNA degradation and repressing translation. Their dynamic expression in different cells and tissues contributes to the regulation of various biological and cellular pathways. As a result, they have become pivotal biomarkers for various diseases, including PCOS, demonstrating intricate associations with diverse health conditions. The aberrant expression of miRNAs has been detected in the serum of women with PCOS, with overexpression and dysregulation of these miRNAs playing a central role in the atypical expression of endocrine hormones linked to PCOS. This review takes a comprehensive approach to explore the upregulation and downregulation of various miRNAs present in ovarian follicular cells, granulosa cells, and theca cells of women diagnosed with PCOS. Furthermore, it discusses the potential for a theragnostic approach using miRNAs to better understand and manage PCOS.

Immune dysfunction mediated by the competitive endogenous RNA network in fetal side placental tissue of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a common endocrine and metabolic disorder affecting women in their reproductive years. Emerging evidence suggests that the maternal-fetal immune system is crucial for proper pregnancy. However, whether immune function is altered at the end of pregnancy in PCOS women and the underlying molecular mechanisms is currently unexplored. Herein, the basic maternal immune system was investigated (n = 136 in the control group; n = 103 in the PCOS group), and whole-transcriptome sequencing was carried out to quantify the mRNAs, miRNAs, and lncRNAs expression levels in fetal side placental tissue of women with PCOS. GO, KEGG, and GSEA analysis were employed for functional enrichment analysis. The process of identifying hub genes was conducted utilizing the protein-protein interaction network. CIBERSORT and Connectivity Map were deployed to determine immune cell infiltration and predict potential drugs, respectively. A network of mRNA-miRNA-lncRNA was constructed and then validated by qRT-PCR. First, red blood cell count, neutrophil count, lymphocyte count, hypersensitive C-reactive protein, and procalcitonin were significantly elevated, while placental growth factor was hindered in PCOS women. We identified 308 DEmRNAs, 77 DEmiRNAs, and 332 DElncRNAs in PCOS samples. Functional enrichment analysis revealed that there were significant changes observed in terms of the immune system, especially the chemokine pathway. Eight genes, including FOS, JUN, EGR1, CXCL10, CXCR1, CXCR2, CXCL11, and CXCL8, were considered as hub genes. Furthermore, the degree of infiltration of neutrophils was dramatically decreased in PCOS tissues. In total, 57 ceRNA events were finally obtained, and immune-related ceRNA networks were validated. Some potential drug candidates, such as enalapril and RS-100329, could have a function in PCOS therapy. This study represents the inaugural attempt to evaluate the immune system at the end of pregnancy and placental ceRNA networks in PCOS, indicating alterations in the chemokine pathway, which may impact fetal and placental growth, and provides new therapy targets.

LncRNA SNHG5 adversely governs follicular growth in PCOS via miR-92a-3p/CDKN1C axis

Small nucleolar RNA host genes (SNHGs) have been implicated in various biological processes, yet their involvement in polycystic ovary syndrome (PCOS) remains elusive. Specifically, SNHG5, a long non-coding RNA implicated in several human cancers, shows elevated expression in granulosa cells (GCs) of PCOS women and induces PCOS-like features when overexpressed in mice. In vitro, SNHG5 inhibits GC proliferation and induces apoptosis and cell-cycle arrest at G0/G1 phase, with RNA-seq indicating its impact on DNA replication and repair pathways. Mechanistically, SNHG5 acts as a competing endogenous RNA by binding to miR-92a-3p, leading to increased expression of target gene CDKN1C, which further suppresses GC proliferation and promotes apoptosis. These findings elucidate the crucial role of SNHG5 in the pathogenesis of PCOS and suggest a potential therapeutic target for this condition. Additional investigations such as large-scale clinical studies and functional assays are warranted to validate and expand upon these findings.

The Role of MicroRNA, Long Non-Coding RNA and Circular RNA in the Pathogenesis of Polycystic Ovary Syndrome: A Literature Review

Polycystic ovary syndrome (PCOS) is the most common endocrine-metabolic disease in females of reproductive age, affecting 4-20% of pre-menopausal women worldwide. MicroRNAs (miRNAs) are endogenous, single-stranded, non-coding, regulatory ribonucleic acid molecules found in eukaryotic cells. Abnormal miRNA expression has been associated with several diseases and could possibly explain their underlying pathophysiology. MiRNAs have been extensively studied for their potential diagnostic, prognostic, and therapeutic uses in many diseases, such as type 2 diabetes, obesity, cardiovascular disease, PCOS, and endometriosis. In women with PCOS, miRNAs were found to be abnormally expressed in theca cells, follicular fluid, granulosa cells, peripheral blood leukocytes, serum, and adipose tissue when compared to those without PCOS, making miRNAs a useful potential biomarker for the disease. Key pathways involved in PCOS, such as folliculogenesis, steroidogenesis, and cellular adhesion, are regulated by miRNA. This also highlights their importance as potential prognostic markers. In addition, recent evidence suggests a role for miRNAs in regulating the circadian rhythm (CR). CR is crucial for regulating reproduction through the various functions of the hypothalamic-pituitary-gonadal (HPG) axis and the ovaries. A disordered CR affects reproductive outcomes by inducing insulin resistance, oxidative stress, and systemic inflammation. Moreover, miRNAs were demonstrated to interact with lncRNA and circRNAs, which are thought to play a role in the pathogenesis of PCOS. This review discusses what is currently understood about miRNAs in PCOS, the cellular pathways involved, and their potential role as biomarkers and therapeutic targets.

Obesity and PCOS radically alters the snRNA composition of follicular fluid extracellular vesicles

Introduction

The ovarian follicle consists of the oocyte, somatic cells, and follicular fluid (FF). Proper signalling between these compartments is required for optimal folliculogenesis. The association between polycystic ovarian syndrome (PCOS) and extracellular vesicular small non-coding RNAs (snRNAs) signatures in follicular fluid (FF) and how this relates to adiposity is unknown. The purpose of this study was to determine whether FF extracellular vesicle (FFEV)-derived snRNAs are differentially expressed (DE) between PCOS and non-PCOS subjects; and if these differences are vesicle-specific and/or adiposity-dependent.

Methods

FF and granulosa cells (GC) were collected from 35 patients matched by demographic and stimulation parameters. FFEVs were isolated and snRNA libraries were constructed, sequenced, and analyzed.

Results

miRNAs were the most abundant biotype present, with specific enrichment in exosomes (EX), whereas in GCs long non-coding RNAs were the most abundant biotype. In obese PCOS vs. lean PCOS, pathway analysis revealed target genes involved in cell survival and apoptosis, leukocyte differentiation and migration, JAK/STAT, and MAPK signalling. In obese PCOS FFEVs were selectively enriched (FFEVs vs. GCs) for miRNAs targeting p53 signalling, cell survival and apoptosis, FOXO, Hippo, TNF, and MAPK signalling.

Discussion

We provide comprehensive profiling of snRNAs in FFEVs and GCs of PCOS and non-PCOS patients, highlighting the effect of adiposity on these findings. We hypothesize that the selective packaging and release of miRNAs specifically targeting anti-apoptotic genes into the FF may be an attempt by the follicle to reduce the apoptotic pressure of the GCs and stave off premature apoptosis of the follicle observed in PCOS.

Multi-omics insights and therapeutic implications in polycystic ovary syndrome: a review

Polycystic ovary syndrome (PCOS) is a common gynecological disease that causes adverse effects in women in their reproductive phase. Nonetheless, the molecular mechanisms remain unclear. Over the last decade, sequencing and omics approaches have advanced at an increased pace. Omics initiatives have come to the forefront of biomedical research by presenting the significance of biological functions and processes. Thus, multi-omics profiling has yielded important insights into understanding the biology of PCOS by identifying potential biomarkers and therapeutic targets. Multi-omics platforms provide high-throughput data to leverage the molecular mechanisms and pathways involving genetic alteration, epigenetic regulation, transcriptional regulation, protein interaction, and metabolic alterations in PCOS. The purpose of this review is to outline the prospects of multi-omics technologies in PCOS research by revealing novel biomarkers and therapeutic targets. Finally, we address the knowledge gaps and emerging treatment strategies for the management of PCOS. Future PCOS research in multi-omics at the single-cell level may enhance diagnostic and treatment options.

Characterization of altered microRNAs related to different phenotypes of polycystic ovarian syndrome (PCOS) in serum, follicular fluid, and cumulus cells

OBJECTIVE

Polycystic ovarian syndrome (PCOS) is a metabolic syndrome in which steroidogenesis, folliculogenesis, and cellular adhesion play crucial roles in its prognosis. These pathways are controlled and regulated by some small non-coding RNAs called microRNAs (miRs). Several miRs have differential expression in PCOS compared to healthy women, and their dysregulation suggests important roles of miRs in PCOS pathophysiology. However, the role of miRs is still unclear, especially in various phenotypes of PCOS.

MATERIALS AND METHODS

This study was conducted to evaluate the diagnostic potential of miR-212-3p, miR-490-5p, miR-647, and miR-4643 in different subtypes of PCOS. Accordingly, nineteen PCOS patients with different subtypes based on Rotterdam criteria (A: 8, B: not detected in this study, C: 5, and D: 6 patients) and six control age and BMI matched women under ICSI treatment were selected. The relative expression of miRs was then measured in blood serum before hormonal treatment (S1) and before ovum pickup (S2), follicular fluid (FF), and cumulus cells (CC) in all subjects. Also, the expression of miRs predicted target genes (AMH, AR, CYP11A1, CYP17A1, CYP19A1, GDF9, and HSD17B12) were done in the CC of understudy groups.

RESULTS

In general, the results indicated that PCOS significantly increased the expression of miR-212-3p, miR-490-5p, and miR-4643 in FF and CCs compared to control. Although these miRs tend to increase in serum 1 of the PCOS patients, the differences were insignificant. However, there was a significant reduction in the expression of miR-647 in FF and CCs between PCOS vs. control. In addition, the miRs had significantly different expressions in various phenotypes of PCOS. For example, high levels of miR-647 in S2 and low levels of miR-490 in FF and miR-212 in CC can differentiate phenotype A from the other. Also, upregulation of miR-212 in FF and miR-4643 in S1 and low levels of this miR in FF can specifically differentiate subtype A from D. On the other hand, high levels of miR-4643 in FF and miR-490 in CC and lower titter of miR-647 can distinguish subtype C from the other. On the other hand, high levels of AMH, AR, CYP11, CYP17, and HSD17 in the hyperandrogenic PCOS and upregulation of CYP19A1 in the hypoandrogenic group can validate the role of selected miRs in the prognosis of PCOS.

CONCLUSION

Characterization of altered microRNAs in serum, FF, and CCs and their targets in CC showed that the miRs might play critical roles in steroidogenesis and folliculogenesis. These miRs may be used for molecular classification of PCOS subtypes and as biomarkers for PCOS diagnosis.

Identification of miR-34-3p as a candidate follicular phase serum marker for endometriosis: a pilot study

OBJECTIVE

To identify early follicular phase microribonucleic acids (miRNAs) that are altered in serum of women with endometriosis.

DESIGN

Case-control study.

SETTING

Large university-affiliated in vitro fertilization center.

PATIENT(S)

Women with (n = 21) and without (n = 24) endometriosis.

INTERVENTION(S)

Serum samples were obtained from laparoscopy-confirmed patients with endometriosis.

MAIN OUTCOME MEASURE(S)

The differential expression of serum miRNAs relative to controls was measured using the NanoString nCounter technology and validated by quantitative real-time polymerase chain reaction in an independent cohort of 27 patients with endometriosis and controls (n = 24). Microribonucleic acid target signaling pathways and genes were analyzed bioinformatically. A chemically modified stable miR-34-3p oligonucleotide was used to examine the effect on proliferation of VK2E6/E7 endometrial cells in vitro.

RESULT(S)

Eighteen miRNAs were significantly up-regulated, and 1 miRNA (hsa-miR-34c-3p) was significantly down-regulated in the follicular phase of patients with endometriosis. The analysis of target signaling pathways using TargetScan predicted regulation of the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B, Hippo, adenosine monophosphate-activated protein kinase, transforming growth factor beta, and endometrial cancer pathways, which have been implicated in the pathogenesis of endometriosis, by these miRNAs. The analysis of sequence complementarity identified prostaglandin E2 receptor 4, interleukin 6 signal transducer, and polo-like kinase 4 genes as possible direct targets of hsa-miR-34-3p. DSDI-1, a chemically modified stable miR-34-3p oligonucleotide, reduced cell proliferation in VK2E6/E7 endometrial cells in vitro.

CONCLUSION(S)

The follicular phase miRNA levels are altered in serum of women with endometriosis and may be useful as reproducible detection biomarkers for early diagnosis of endometriosis. hsa-miR-34-3p is significantly down-regulated in endometriosis, targets endometriosis genes, and reduces endometrial cell proliferation in vitro. These results support hsa-miR-34-3p as a potential therapeutic target in endometriosis.

The Translational Role of miRNA in Polycystic Ovary Syndrome: From Bench to Bedside—A Systematic Literature Review

MicroRNAs (miRNAs) are small, non-coding RNAs that are essential for the regulation of post-transcriptional gene expression during tissue development and differentiation. They are involved in the regulation of manifold metabolic and hormonal processes and, within the female reproductive tract, in oocyte maturation and folliculogenesis. Altered miRNA levels have been observed in oncological and inflammatory diseases, diabetes or polycystic ovary syndrome (PCOS). Therefore, miRNAs are proving to be promising potential biomarkers. In women with PCOS, circulating miRNAs can be obtained from whole blood, serum, plasma, urine, and follicular fluid. Our systematic review summarizes data from 2010–2021 on miRNA expression in granulosa and theca cells; the relationship between miRNAs, hormonal changes, glucose and lipid metabolism in women with PCOS; and the potential role of altered miRNAs in fertility (oocyte quality) in PCOS. Furthermore, we discuss miRNAs as a potential therapeutic target in PCOS and as a diagnostic marker for PCOS.

Metabolic and Molecular Mechanisms of Diet and Physical Exercise in the Management of Polycystic Ovarian Syndrome

Polycystic ovary syndrome (PCOS) is an endocrine systemic disorder mainly characterized by a hormonal and metabolic disbalance that leads to oligo/anovulation, hyperandrogenism and the formation of ovarian cysts. Despite the progress that has been reached in its diagnosis and management, little is known about the molecular mechanisms and signaling pathways underlying the pathogenic mechanisms. In this sense, recent research has suggested that the influence of multiple factors, including age, environment, lifestyle and the disease state environment can change the clinical presentation of PCOS via epigenetic modifications. Variants in the genes encoding for proteins involved in steroidogenesis and glucose homeostasis play a crucial role in the development of the disease. Other genes involved in inflammation and cell proliferation seem to undergo an epigenetic control. Moreover, lifestyle factors influence the PCOS course and prognosis, including diet and physical activity, which are fundamental in reducing oxidative stress, inflammation and in improving metabolic and hormonal parameters. In the present review, literature evidence on molecular and epigenetic mechanisms related to PCOS etiology will be discussed, with a particular attention on the positive influence of diet and physical activity as nonpharmacological ways of intervention in the management of the disease.

A Brief Review on the Regulatory Roles of MicroRNAs in Cystic Diseases and Their Use as Potential Biomarkers

miRNAs are small endogenous conserved non-coding RNA molecules that regulate post-transcriptional gene expression through mRNA degradation or translational inhibition, modulating nearly 60% of human genes. Cystic diseases are characterized by the presence of abnormal fluid-filled sacs in the body, and though most cysts are benign, they can grow inside tumors and turn malignant. Recent evidence has revealed that the aberrant expression of a number of miRNAs present in extracellular fluids, including plasma or serum, urine, saliva, follicular fluid, and semen, contribute to different cystic pathologies. This review aims to describe the role of different miRNAs in three worldwide relevant cystic diseases: polycystic ovarian syndrome (PCOS), polycystic kidney disease (PKD), and pancreatic cyst tumors (PCTs), as well as their potential use as novel biomarkers.

A Brief Review on the Regulatory Roles of MicroRNAs in Cystic Diseases and Their Use as Potential Biomarkers

miRNAs are small endogenous conserved non-coding RNA molecules that regulate post-transcriptional gene expression through mRNA degradation or translational inhibition, modulating nearly 60% of human genes. Cystic diseases are characterized by the presence of abnormal fluid-filled sacs in the body, and though most cysts are benign, they can grow inside tumors and turn malignant. Recent evidence has revealed that the aberrant expression of a number of miRNAs present in extracellular fluids, including plasma or serum, urine, saliva, follicular fluid, and semen, contribute to different cystic pathologies. This review aims to describe the role of different miRNAs in three worldwide relevant cystic diseases: polycystic ovarian syndrome (PCOS), polycystic kidney disease (PKD), and pancreatic cyst tumors (PCTs), as well as their potential use as novel biomarkers.

A Brief Review on the Regulatory Roles of MicroRNAs in Cystic Diseases and Their Use as Potential Biomarkers

miRNAs are small endogenous conserved non-coding RNA molecules that regulate post-transcriptional gene expression through mRNA degradation or translational inhibition, modulating nearly 60% of human genes. Cystic diseases are characterized by the presence of abnormal fluid-filled sacs in the body, and though most cysts are benign, they can grow inside tumors and turn malignant. Recent evidence has revealed that the aberrant expression of a number of miRNAs present in extracellular fluids, including plasma or serum, urine, saliva, follicular fluid, and semen, contribute to different cystic pathologies. This review aims to describe the role of different miRNAs in three worldwide relevant cystic diseases: polycystic ovarian syndrome (PCOS), polycystic kidney disease (PKD), and pancreatic cyst tumors (PCTs), as well as their potential use as novel biomarkers.

Molecular Features of Polycystic Ovary Syndrome Revealed by Transcriptome Analysis of Oocytes and Cumulus Cells

Polycystic ovary syndrome (PCOS) is typically characterized by a polycystic ovarian morphology, hyperandrogenism, ovulatory dysfunction, and infertility. Furthermore, PCOS patients undergoing ovarian stimulation have more oocytes; however, the poor quality of oocytes leads to lower fertilization and implantation rates, decreased pregnancy rates, and increased miscarriage rates. The complex molecular mechanisms underlying PCOS and the poor quality of oocytes remain to be elucidated. We obtained matched oocytes and cumulus cells (CCs) from PCOS patients, compared them with age-matched controls, and performed RNA sequencing analysis to explore the transcriptional characteristics of their oocytes and CCs. Moreover, we validated our newly confirmed candidate genes for PCOS by immunofluorescence. Unsupervised clustering analysis showed that the overall global gene expression patterns and transposable element (TE) expression profiles of PCOS patients tightly clustered together, clearly distinct from those of controls. Abnormalities in functionally important pathways are found in PCOS oocytes. Notably, genes involved in microtubule processes, TUBB8 and TUBA1C, are overexpressed in PCOS oocytes. The metabolic and oxidative phosphorylation pathways are also dysregulated in both oocytes and CCs from PCOS patients. Moreover, in oocytes, differentially expressed TEs are not uniformly dispersed in human chromosomes. Endogenous retrovirus 1 (ERV1) elements located on chromosomes 2, 3, 4, and 5 are rather highly upregulated. Interestingly, these correlate with the most highly expressed protein-coding genes, including tubulin-associated genes TUBA1C, TUBB8P8, and TUBB8, linking the ERV1 elements to the occurrence of PCOS. Our comprehensive analysis of gene expression in oocytes and CCs, including TE expression, revealed the specific molecular features of PCOS. The aberrantly elevated expression of TUBB8 and TUBA1C and ERV1 provides additional markers for PCOS and may contribute to the compromised oocyte developmental competence in PCOS patients. Our findings may also have implications for treatment strategies to improve oocyte maturation and the pregnancy outcomes for women with PCOS.

miR-130b regulates gap junctional intercellular communication through connexin 43 in granulosa cells from patients with polycystic ovary syndrome

MicroRNAs (miRNAs) are small, noncoding RNAs that negatively regulate gene expression post-transcriptionally. We explored whether connexin 43 (Cx43) was differently expressed in luteinized granulosa cells from women with polycystic ovary syndrome (PCOS) compared with luteinized granulosa cells from women with a normal menstrual cycle, and whether certain miRNAs regulate the Cx43 level and gap junctional intercellular communication (GJIC). The miRNA profile was investigated in ovarian cortex tissues from five women with PCOS and five women without PCOS using a miRNA microarray. The levels of miR-130b and Cx43 mRNA were measured using real-time PCR in human luteinized granulosa cells from 20 women with PCOS and 25 women without PCOS. Protein and mRNA expression analysis and luciferase assays were conducted to confirm the substrate of miR-130b. PCOS ovarian cortex showed differential expression of miRNAs compared with non-PCOS ovarian cortex. Furthermore, miR-130b levels were increased in PCOS ovarian cortex and in luteinized granulosa cells compared with those in women with normal menstrual cycles, whereas the level of Cx43 mRNA, the identified target of miR-130b, was decreased in granulosa cells from patients with PCOS. Overexpression of miR-130b in a granulosa cell line resulted in reduced Cx43 protein levels and inhibited GJIC using scrape loading and dye transfer assay. Meanwhile, inhibition of miR-130b increased the Cx43 level. In conclusion, miR-130b was increased in PCOS granulosa cells, where it targets Cx43 to affect GJIC. The results of the present study suggested that miR-130b, via post-transcriptional regulation of Cx43, is involved in the pathophysiology of PCOS, which provides new insight into the pathological mechanism of PCOS.

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.

Role of Lipid Metabolism and Signaling in Mammalian Oocyte Maturation, Quality, and Acquisition of Competence

It has been found that the quality of oocytes from obese women has been compromised and subsequent embryos displayed arrested development. The compromised quality may be either due to the poor or rich metabolic conditions such as imbalance or excession of lipids during oocyte development. Generally, lipids are mainly stored in the form of lipid droplets and are an important source of energy metabolism. Similarly, lipids are also essential signaling molecules involved in various biological cascades of oocyte maturation, growth and oocyte competence acquisition. To understand the role of lipids in controlling the oocyte development, we have comprehensively and concisely reviewed the literature and described the role of lipid metabolism in oocyte quality and maturation. Moreover, we have also presented a simplified model of fatty acid metabolism along with its implication on determining the oocyte quality and cryopreservation for fertilization.

Genetic Susceptibility to Joint Occurrence of Polycystic Ovary Syndrome and Hashimoto's Thyroiditis: How Far Is Our Understanding?

Polycystic ovary syndrome (PCOS) and Hashimoto’s thyroiditis (HT) are endocrine disorders that commonly occur among young women. A higher prevalence of HT in women with PCOS, relative to healthy individuals, is observed consistently. Combined occurrence of both diseases is associated with a higher risk of severe metabolic and reproductive complications. Genetic factors strongly impact the pathogenesis of both PCOS and HT and several susceptibility loci associated with a higher risk of both disorders have been identified. Furthermore, some candidate gene polymorphisms are thought to be functionally relevant; however, few genetic variants are proposed to be causally associated with the incidence of both disorders together.

Non-coding RNAs in polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Genetic, environmental and epigenetical factors may play important roles in the pathogenesis of polycystic ovary syndrome (PCOS), however the etiology of PCOS remains unclear. Studies indicated that non-coding RNAs (ncRNAs) were involved in the occurrence and development of PCOS. Thus, we aim to perform a systematic review and meta-analysis to investigate the presence and dysregulated expression of ncRNAs in human PCOS.

METHODS

We searched in PubMed, Medline, Web of Science and Embase until July 2019 and summarized all eligible publications focusing on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and small interfering RNAs (siRNAs) in PCOS.

RESULTS

Sixty-seven articles were included in our systematic review and 9 articles were included in meta-analysis. There is little overlap between studies when comparing miRNA profiles. Sensitivity analysis showed that the expression of miR-93 was upregulated in PCOS patients (WMD 0.75, P < 0.00001), without heterogeneity among remaining studies (I2 = 0%).

CONCLUSION

A large number of ncRNAs with altered levels were observed in plasma, serum, follicular fluid, granulosa cells or other issues from PCOS patients. Aberrant ncRNAs expression in PCOS may lead to aberrant steroidogenesis, adipocyte dysfunction, altered ovarian cell proliferation and/or apoptosis and have the potential to be used as diagnostic biomarkers.

The role of miRNAs in polycystic ovary syndrome with insulin resistance

PURPOSE

This review aims to summarize the key findings of several miRNAs and their roles in polycystic ovary syndrome with insulin resistance, characterize the disease pathogenesis, and establish a new theoretical basis for diagnosing, treating, and preventing polycystic ovary syndrome.

METHODS

Relevant scientific literature was covered from 1992 to 2020 by searching the PubMed database with search terms: insulin/insulin resistance, polycystic ovary syndrome, microRNAs, and metabolic diseases. References of relevant studies were cross-checked.

RESULTS

The related miRNAs (including differentially expressed miRNAs) and their roles in pathogenesis, and possible therapeutic targets and pathways, are discussed, highlighting controversies and offering thoughts for future directions.

CONCLUSION

We found abundant evidence on the role of differentially expressed miRNAs with its related phenotypes in PCOS. Considering the essential role of insulin resistance in the pathogenesis of PCOS, the alterations of associated miRNAs need more research attention. We speculate that race/ethnicity or PCOS phenotype and differences in methodological differences might lead to inconsistencies in research findings; thus, several miRNA profiles need to be investigated further to qualify for the potential therapeutic targets for PCOS-IR.

Transcriptome Analysis of the Chicken Follicular Theca Cells with miR-135a-5p Suppressed

As a class of transcription regulators, numerous miRNAs have been verified to participate in regulating ovary follicular development in chickens (Gallus gallus). Previously we showed that gga-miR-135a-5p has significant differential expression between high and low-yield chicken ovaries, and the abundance of gga-miR-135a-5p is significantly higher in follicular theca cells than in granulosa cells. However, the exact role of gga-miR-135a-5p in chicken follicular theca cells is unclear. In this study, primary chicken follicular theca cells were isolated and then transfected with gga-miR-135a-5p inhibitor. Transcriptome sequencing was performed in chicken follicular theca cells with or without transfection. Differentially expressed genes (DEGs) were analyzed using bioinformatics. A dual-luciferase reporter assay was used to verify the target relationship between gga-miR-135a-5p and predicted targets within the DEGs. Compared with the normal chicken follicle theca cells, 953 up-regulated and 1060 down-regulated genes were detected in cells with gga-miR-135a-5p inhibited. The up-regulated genes were significantly enriched in Gene Ontology terms and pathways involved in cell proliferation and differentiation. In chicken follicular theca cells, Krüppel-like factor 4 (KLF4), ATPase phospholipid transporting 8A1 (ATP8A1), and Complexin-1 (CPLX1) were significantly up-regulated when the expression of gga-miR-135a-5p was inhibited. In addition, KLF4, ATP8A1, and CPLX1 confirmed as targets of gga-miR-135a-5p by using a dual-luciferase assay in vitro. The results suggest that gga-mir-135a-5p may involve in proliferation and differentiation in chicken ovarian follicular theca cells by targeting KLF4, ATP8A1, and CPLX1.

miRNAs as a novel clinical biomarker and therapeutic targets in polycystic ovary syndrome (PCOS): A review

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine disorder in females of the reproductive age. PCOS is commonly manifested as ovulatory dysfunction, clinical and biochemical excess androgen level, and polycystic ovaries. Metabolic sequelae associated with PCOS, including insulin resistance (IR), type 2 diabetes (T2DM), obesity and increased cardiometabolic risk. The underlying pathology of PCOS is not fully understood with various genetic and environmental factors have been proposed. MicroRNAs (miRNAs), are endogenously produced, small non-coding, single-stranded RNAs that capable of regulating gene expression at the post-transcriptional level. Altered miRNAs expression has been associated with various disorders, including T2DM, IR, lipid disorder, infertility, atherosclerosis, endometriosis, and cancer. Given that PCOS also present with similar features, there is an increasing interest to investigate the role of miRNAs in the diagnosis and management of PCOS. In recent years, studies have demonstrated that miRNAs are present in various body fluids, including follicular fluid of women with PCOS. Therefore, it may act as a potential biomarker and could serve as a novel therapeutic target for the diagnosis and treatment of PCOS. This review aims to summarise the up to date research on the relation between miRNAs and PCOS and explore its potential role in the diagnosis and the management of PCOS.

microRNA Expression in Women With and Without Polycystic Ovarian Syndrome Matched for Body Mass Index

Background: Despite several authors who have hypothesized that alterations of small noncoding RNAs (miR) are implicated in the etiopathogenesis of polycystic ovarian syndrome (PCOS), contrasting findings have been reported so far. Discrepancies in body mass index (BMI) levels may account for these differences; therefore, the aim of the present study was to determine whether miR differed in serum samples collected from age- and BMI-matched control and PCOS women. Methods: In a cross-sectional study, miR were measured using quantitative polymerase chain reaction in 29 women with anovulatory PCOS women and 29 control women who were in the follicular phase of their menstrual cycle, from the local biobank. Results: One hundred seventy-six miR were detected, of which 15 miR passed the false discovery rate (FDR; p < 0.05) that differed between PCOS and control women. There was no association of the top 9 miR (p < 0.02) (miR-486-5p, miR-24-3p, miR-19b-3p, miR-22-3p, miR-19a-3p, miR-339-5p, miR-185-5p, miR-101-3p, miR-let-7i-5p) with BMI, androgen levels, insulin resistance, or antimullerian hormone (AMH) in either PCOS or normal women. Ingenuity pathway assessment showed the pathways were interrelated for abnormalities of the reproductive system. Conclusion: When the confounding influence of weight was accounted for, miR levels differed between anovulatory PCOS women and control women in the follicular phase of the menstrual cycle. Interestingly, the differing miR were associated with the pathways of reproductive abnormalities but did not associate with AMH or metabolic parameters.

Recent advances in mammalian reproductive biology

Reproductive biology is a uniquely important topic since it is about germ cells, which are central for transmitting genetic information from generation to generation. In this review, we discuss recent advances in mammalian germ cell development, including preimplantation development, fetal germ cell development and postnatal development of oocytes and sperm. We also discuss the etiologies of female and male infertility and describe the emerging technologies for studying reproductive biology such as gene editing and single-cell technologies.

Expression of microRNA in follicular fluid in women with and without PCOS

Several studies have shown the expression of small non-coding microRNA (miRNA) changes in PCOS and their expression in follicular fluid has been described, though the number of studies remains small. In this prospective cohort study, miRNA were measured using quantitative polymerase chain reaction (qPCR) in 29 weight and aged matched anovulatory women with PCOS and 30 women without from follicular fluid taken at the time of oocyte retrieval who were undergoing in vitro fertilization (IVF); miRNA levels were determined from a miRNA data set. 176 miRNA were detected, of which 29 differed significantly between normal women and PCOS women. Of these, the top 7 (p < 0.015) were miR-381-3p, miR-199b-5p, miR-93-3p, miR-361-3p, miR-127-3p, miR-382-5p, miR-425-3p. In PCOS, miR-382-5p correlated with age and free androgen index (FAI), miR-199b-5p correlated with anti-mullerian hormone (AMH) and miR-93-3p correlated with C-reactive protein (CRP). In normal controls, miR-127-3p, miR-382-5p and miR-425-3p correlated with the fertilisation rate; miR-127-3p correlated with insulin resistance and miR-381-3p correlated with FAI. Ingenuity pathway assessment revealed that 12 of the significantly altered miRNA related to reproductive pathways, 12 miRNA related to the inflammatory disease pathway and 6 were implicated in benign pelvic disease. MiRNAs differed in the follicular fluid between PCOS and normal control women, correlating with age, FAI, inflammation and AMH in PCOS, and with BMI, fertilization rate (3 miRNA), insulin resistance, FAI and inflammation in control women, according to Ingenuity Pathway Analysis.

miRNA Profiling Reveals miRNA-130b-3p Mediates DENND1A Variant 2 Expression and Androgen Biosynthesis

Polycystic ovary syndrome (PCOS) is a common endocrine disorder of reproductive-age women involving overproduction of ovarian androgens and, in some cases, from the adrenal cortex. Family studies have established that PCOS is a complex heritable disorder with genetic and epigenetic components. Several small, noncoding RNAs (miRNAs) have been shown to be differentially expressed in ovarian cells and follicular fluid and in the circulation of women with PCOS. However, there are no reports of global miRNA expression and target gene analyses in ovarian theca cells isolated from normal cycling women and women with PCOS, which are key to the elucidation of the basis for the hyperandrogenemia characteristic of PCOS. With the use of small RNA deep sequencing (miR-seq), we identified 18 differentially expressed miRNAs in PCOS theca cells; of these, miR-130b-3p was predicted to target one of the PCOS genome-wide association study candidates, differentially expressed in neoplastic vs normal cells domain containing 1A (DENND1A). We previously reported that DENND1A variant 2 (DENND1A.V2), a truncated isoform of DENND1A, is upregulated in PCOS theca cells and mediates augmented androgen biosynthesis in PCOS theca cells. The comparison of miR-130b-3p in normal and PCOS theca cells demonstrated decreased miR-130b-3p expression in PCOS theca cells, which was correlated with increased DENND1A.V2, cytochrome P450 17α-hydroxylase (CYP17A1) mRNA and androgen biosynthesis. miR-130b-3p mimic studies established that increased miR130b-3p is correlated with decreased DENND1A.V2 and CYP17A1 expression. Thus, in addition to genetic factors, post-transcriptional regulatory mechanisms via miR-130b-3p underly androgen excess in PCOS. Ingenuity® Pathway Analysis Core Pathway and Network Analyses suggest a network by which miR-130b-3p, DENND1A, the luteinizing hormone/choriogonadotropin receptor, Ras-related protein 5B, and signaling pathways that they potentially target may mediate hyperandrogenism in PCOS.

The role of microRNAs in the regulation of insulin signaling pathway with respect to metabolic and mitogenic cascades: A review

Insulin resistance (IR) is a shared pathological condition among type 2 diabetes, obesity, cardiovascular disease, and other metabolic disorders. It is growing significantly all over the world and consequently, a substantial effort is needed for developing the potential novel diagnostics and therapeutics. An insulin signaling pathway is tightly modulated by different mechanisms including the epigenetic modifications. Today, a deal of great attention has been shifted towards the regulatory role of noncoding RNAs on target proteins of the insulin signaling pathway. Noncoding RNAs are a major area of the epigenetics which control gene expression at the posttranscriptional levels and include a large class of microRNAs (miRNAs). With this in view, many studies have implicated the mediatory effects of miRNAs on the downstream metabolic and mitogenic proteins of the insulin signaling pathway. Since providing new biomarkers for the early diagnosis of IR and related metabolic traits are very significant, we intended to review the possible role of miRNAs in the regulation of the insulin signaling pathway, with a primary focus on the downstream target proteins of the metabolic and mitogenic cascades.

The role of MiRNA in polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in reproductive-aged women. Clinical manifestations include hyperandrogenism, chronic anovulation, polycystic ovaries and being frequently accompanied by insulin resistance (IR) and obesity. MicroRNAs (miRNAs) are short non-coding RNAs which are involved in the regulation of gene expression at the post-transcriptional level. Altered miRNAs levels have been showed to be associated with a variety of diseases including diabetes, endometriosis and cancer. In recent years, more and more evidence suggests abnormal expression of miRNAs are detected in granulosa cells, theca cells, adipose tissue, follicular fluid, serum and peripheral blood leukocytes of women with PCOS and display vital role in the occurrence and development of PCOS. This will shed light on new strategies for the diagnosis and treatment of this syndrome. In this paper, we will review the recent research on miRNAs with respect to PCOS.

Evaluation of Serum miRNA-24, miRNA-29a and miRNA-502-3p Expression in PCOS Subjects: Correlation with Biochemical Parameters Related to PCOS and Insulin Resistance

MicroRNAs (miRNAs) are small, endogenous, non-coding, single stranded RNAs which play a role in the regulation of gene expression and function. Therefore, the analysis of differentially expressed miRNAs are of great importance in disease diagnosis. This study is focussed on the differential expression of miRNAs in serum of PCOS subjects compared to control and their correlation with metabolic and endocrine parameters. Anthropometry, hormone concentrations and biochemical characteristics were measured in healthy (n = 20) and PCOS (n = 20) subjects. MiR-24, miR-29a and miR-502-3p were determined in serum by quantitative RT-PCR. The levels of miR-24 was significantly decreased in PCOS subjects (P = 0.00) compared to control. No significant difference was observed in the levels of miR-29a and miR-502-3p in PCOS and control subjects. MiR-24 showed significant inverse correlation with BMI, glucose, insulin, FIRI, HOMA, LH, testosterone, TG, and LH:FSH ratio whereas HDL levels showed significant positive association with miR-24 and miR-29a. LH showed significant negative association with miR-29a. No correlation was observed between the expression of miR-502-3p with any of the studied parameters. The receiver operating characteristic curve for miR-24 alone showed a significant discriminative capacity. The study suggests that serum miR-24 analysis in PCOS patients could be of diagnostic value that can be used as a biomarker for PCOS.

MicroRNA 221 expression in theca and granulosa cells: hormonal regulation and function

Small noncoding RNA molecules (miRNA) regulate protein levels in a post-transcriptional manner by partial base pairing to the 3'-UTR of target genes thus mediating degradation or translational repression. Previous studies indicate that numerous miRNA regulate the biosynthesis of intraovarian hormones, and emerging evidence indicates that one of these, miRNA-221 (MIR221), may be a modulator of ovarian function. However, the hormonal control of ovarian MIR221 is not known. The objectives of this study were to investigate the developmental and hormonal regulation of MIR221 expression in granulosa (GC) and theca cell (TC) and its possible role in regulating follicular function. Bovine ovaries were collected from a local abattoir and GC and TC were obtained from small (<6 mm) and large (≥8 mm) follicles. In Exp. 1, GCs of small follicles had 9.7-fold greater (P < 0.001) levels of MIR221 than those of large follicles, and TCs of large follicles had 3.7-fold greater (P < 0.001) levels of MIR221 than those of small follicles. In large follicles, abundance of MIR221 was 66.6-fold greater (P < 0.001) in TCs than in GCs. In small follicles, MIR221 abundance did not differ (P = 0.14) between GC and TCs. In vitro Exp. 2, 3, and 4 revealed that treatment of bovine TCs with various steroids, phytoestrogens, IGF1, forskolin, and dibutyryl cyclic adenosine monophosphate had no effect (P > 0.35) on MIR221 expression, whereas treatment with fibroblast growth factor 9 (FGF9) and FGF2 increased (P < 0.001) TC MIR221 abundance 1.7- to 2.5-fold. In Exp. 5, FGF9 increased (P < 0.05) GC MIR221 abundance by 1.7- and 2.0-fold in small and large follicles, respectively. The role of MIR221 in GC steroidogenesis was investigated in Exp. 6 and it was found that transfection with a MIR221 mimic reduced (P < 0.01) GC estradiol and progesterone production induced by FSH and IGF1, whereas transfection with MIR221 inhibitor had little or no effect. We conclude that thecal MIR221 expression is increased by FGF9 and increased MIR221 may act to inhibit GC steroidogenesis in cattle.

Identification of microRNAs and genes associated with hyperandrogenism in the follicular fluid of women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease, which is characterized by hyperandrogenism (HA), chronic anovulation, polycystic ovaries, insulin resistance, and obesity. At present, the mechanism by which PCOS/HA occurs has not been fully elucidated, thus, the mechanisms behind and interventions for HA in PCOS are current hot topics in research. MiRNAs have recently been shown to serve as diagnostic or prognostic biomarkers in patients with cancer. Thus, we are currently focused on studying the altered expression of miRNAs in follicular fluid and their correlation with HA in PCOS. Illumina deep sequencing technology was used to explore different miRNAs in the follicular fluid of women with PCOS/HA and in the follicular fluid of women in a control group. Target prediction databases were then used to analyse the target genes of different expressed miRNAs, and GO analysis and the KEGG pathway database were used to identify the functions and the main biochemical and signalling pathways of differentially expressed target genes. The expression levels of 263 miRNAs were significantly different (>2-fold up-regulated or <0.5-fold down-regulated, P < 0.05) between the two groups of women. For example, the expression levels of miRNA (200a-3p, 10b-3p, 200b-3p, 29c-3p, 99a-3p, and 125a-5p) were significantly increased, while there was a decreased expression of miR-105-3p in PCOS patients with respect to the control. Literature has shown that the above seven miRNAs were associated with HA in PCOS. Furthermore, 31 770 genes were predicted to be targets of the 263 differentially expressed microRNAs. GO analysis and the KEGG pathway database showed involvement of these target genes in HA in PCOS. These results suggest the presence of differentially expressed miRNAs in the follicular fluid of women with PCOS/HA versus women in the control group. The potential role of these microRNAs was elucidated using bioinformatics tools and was found to be involved in the regulation of different pathways, biological functions, and cellular components underlying PCOS. The results of this research may reveal new mechanisms of PCOS/HA and suggest potential treatment targets.

Non‑coding RNAs and ovarian diseases (Review)

Non-coding RNAs (ncRNAs) are a diverse family of untranslated transcripts, which serve important roles in numerous biological processes. ncRNAs are emerging as major mediators of gene expression with crucial regulatory functions. Ovarian diseases have a wide variety of clinical pathological types, which have serious impacts on women's health. In this review, current studies on ncRNAs are summarized with respect to ovarian diseases. Understanding of the role of ncRNAs in ovarian diseases is currently limited; further studies on the molecular mechanisms by which abnormal expression of ncRNAs contributes to ovarian diseases will aid in the identification of ncRNAs as novel diagnostic markers and therapeutic targets for ovarian diseases.

A syntenic locus on buffalo chromosome 20: novel genomic hotspot for miRNAs involved in follicular-luteal transition

The developmental reorganization of ovarian follicular granulosa cells (GC) during follicular maturation, ovulation, and luteinization require a well-controlled regulation of dynamic gene expression profiles. Recently, microRNAs (miRNAs) were found to be key players of ovarian follicular dynamics. The current study aimed to understand the miRNA regulatory role in follicular-luteal transition by characterizing the miRNA profile through miRNA-seq at different follicular (small, medium, and large) and luteal (early, mid, and late) stages in Indian water buffaloes, mono-ovulatory animals like humans. A total of 517 miRNAs were identified in follicular granulosa cells (GC) and corpus luteum (CL) together. Among them, 2 unique and 40 novel miRNAs were in GC; 15 unique and 45 novel miRNAs were in CL. Among the remaining 415 annotated common miRNAs between GC and CL, 43 have showed significant (p < 0.05) differential expression between GC and CL. Particularly, 39 and 4 miRNAs showed higher expression in CL and GC, respectively, with respect to each other. Genome mapping analysis revealed that 71.7% of differential miRNAs having higher expression in CL compared to GC, and 93% of the unique miRNAs in CL were mapped to a short chromosomal region of 0.7 Mb (67.4 to 68.1 Mb) on chromosome 21 of cows which is syntenic to the buffalo chromosome 20. Clustering of all these miRNAs at this locus suggests it as a chromosomal hotspot for miRNAs involved in follicular-luteal transition, especially for CL physiological functions.

MicroRNA Expression is Altered in Granulosa Cells of Ovarian Hyperresponders

Controlled ovarian stimulation plays an integral role in assisted reproduction technology, but individual patients have different responses to exogenous gonadotropins. In order to determine whether microRNAs (miRNAs) have a regulatory role in ovarian response, we profiled the expression of microRNAs in isolated ovarian granulosa cells collected from ovarian hyperresponders and normal responders using microarrays and validated the expression of selected miRNAs using quantitative polymerase chain reaction (PCR). There were 81 miRNAs differentially expressed between the 2 groups, with 45 increased and 36 decreased in the high response group. Bioinformatics analysis of these altered miRNAs and their target genes revealed some significantly enriched pathways, including regulation of the cell cycle, transcription, cell proliferation, and gonadotrophin releasing hormone signaling pathway. The expression of hsa-miR-513a-5p, hsa-miR-27b-3p, hsa-miR-19b-3p, hsa-miR-3201, hsa-miR-423-5p, hsa-miR-193b-5p, and hsa-miR-202-3p was validated by real-time PCR. Hsa-miR-423-5p, predicted to target anti-Mullerian hormone, cytochrome P450, family 19, subfamily A, polypeptide 1, methylenetetrahydrofolate reductase, progesterone receptor, and follicle stimulating hormone, β-polypeptide was found to have significantly decreased expression in the hyperresponders (P = .023). Hsa-miR-193b-5p also showed a tendency to be significantly decreased in the hyperresponders (P = .093). In conclusion, our findings provide evidence for altered miRNA expression in granulosa cells of women with ovarian hyperresponse, suggesting a role of miRNAs in regulating ovarian response to gonadotropins.

Differential Expression of microRNAs in the Ovaries from Letrozole-Induced Rat Model of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder. To understand the pathogenesis of PCOS, we established rat models of PCOS induced by letrozole and employed deep sequencing to screen the differential expression of microRNAs (miRNAs) in PCOS rats and control rats. We observed vaginal smear and detected ovarian pathological alteration and hormone level changes in PCOS rats. Deep sequencing showed that a total of 129 miRNAs were differentially expressed in the ovaries from letrozole-induced rat model compared with the control, including 49 miRNAs upregulated and 80 miRNAs downregulated. Furthermore, the differential expression of miR-201-5p, miR-34b-5p, miR-141-3p, and miR-200a-3p were confirmed by real-time polymerase chain reaction. Bioinformatic analysis revealed that these four miRNAs were predicted to target a large set of genes with different functions. Pathway analysis supported that the miRNAs regulate oocyte meiosis, mitogen-activated protein kinase (MAPK) signaling, phosphoinositide 3-kinase/Akt (PI3K-Akt) signaling, Rap1 signaling, and Notch signaling. These data indicate that miRNAs are differentially expressed in rat PCOS model and the differentially expressed miRNA are involved in the etiology and pathophysiology of PCOS. Our findings will help identify miRNAs as novel diagnostic markers and therapeutic targets for PCOS.

miRNA-592 is downregulated and may target LHCGR in polycystic ovary syndrome patients

The polycystic ovary syndrome (PCOS) is an endocrine disorder mainly associated with infertility. Abnormal regulation of relevant genes is required for follicular development in PCOS. In the current study, the expression of serum miRNAs of PCOS patients was explored using miRNA array followed by qRT-PCR assays. The circulating level of miR-592 was significantly down-regulated in PCOS patients in comparison with healthy controls. Furthermore, we found that miR-592 was inversely correlated with the level of luteinizing hormone/chorionic gonadotropin receptor (LHCGR). Computational analysis predicted that miR-592 interacts with the LHCGR mRNA via binding to a site located in the 3'UTR region. Using a luciferase-based reporter assay we found that miR-592 directly targeted the LHCGR. In KGN cell line, miR-592 overexpression inhibited cell viability and the transition of phase G1 to phase S. Knocking down of LHCGR inhibited cell viability and cell cycle progression in KGN cells, and LHCGR co-transfection reversed the inhibitory effect of miR-592. These results shed new light on the diagnosis and treatment of PCOS syndrome.