Differential gene expression in granulosa cells from polycystic ovary syndrome patients with and without insulin resistance: identification of susceptibility gene sets through network analysis

Bioinformatics analysis of the role of RNA modification regulators in polycystic ovary syndrome

Purpose

Polycystic ovary syndrome (PCOS) is the most common metabolic and endocrine disorder affecting women of reproductive age. The pathogenesis of PCOS is influenced by factors such as race, genetics, environment, hyperandrogenemia, hyperinsulinemia, and obesity. However, the molecular mechanisms linking RNA modification and PCOS remain underexplored. This study aims to investigate the potential genetic and molecular pathways connecting RNA modification with PCOS through bioinformatics analyses.

Methods

The GSE34526, GSE5850, and GSE98421 datasets were obtained from the National Center for Biotechnology Information Gene Expression Omnibus database. We identified intersecting differentially expressed genes (DEGs) and RNA modification-related genes within the GSE34526 dataset and visualized the overlaps using a Venn diagram. Subsequent analyses included Gene Ontology (GO), pathway enrichment (Kyoto Encyclopedia of Genes and Genomes), gene set enrichment analysis (GSEA), gene set variation analysis (GSVA), and immune infiltration analysis. Additionally, we constructed a protein-protein interaction network as well as mRNA-miRNA, mRNA-RNA binding protein, and mRNA-transcription factor (TF) regulatory networks. The expression and receiver operating characteristic curves of hub genes were also identified.

Results

The expression of several RNA modification-related DEGs (RMRDEGs) (ALYREF, NUDT1, AGO2, TET2, YTHDF2, and TRMT61B) showed significant differences in PCOS patients. GSEA and GSVA indicated that RMRDEGs were enriched in the hedgehog, MAPK, JAK STAT, and Notch pathways. Key transcription factors, including SP7, KLF8, HCFC1, IRF1, and MLLT1, were identified in the TF regulatory networks.

Conclusions

These findings suggest that there are gene and miRNA profile alterations exist in PCOS patients and highlight immune-related differences. This knowledge could pave the way for new research directions in the diagnosis and treatment of PCOS.

Analysis of macrophage polarization and regulation characteristics in ovarian tissues of polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) can lead to infertility and increase the risk of endometrial cancer. Analyzing the macrophage polarization characteristics in ovarian tissues of PCOS is crucial for clinical treatment.

Methods

We obtained 13 PCOS and nine control ovarian samples from the CEO database and analyzed differentially expressed genes (DEGs). Macrophage polarization-related genes (MPRGs) were sourced from the GeneCards and MSigDB databases. Intersection of DEGs with MPRGs identified DEGs associated with macrophage polarization (MPRDEGs). Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-protein interaction (PPI) Network analysis were conducted on MPRDEGs. Moreover, the top 10 genes from three algorithms were identified as the hub genes of MPRGs. In addition, miRNAs, transcription factors (TFs), and drugs were retrieved from relevant databases for regulatory network analysis of mRNA-miRNA, mRNA-TF, and mRNA-Drug interactions. Immune cell composition analysis between the PCOS and control groups was performed using the CIBERSORT algorithm to calculate correlations across 22 immune cell types.

Results

A total of 13 PCOS samples and nine control ovarian samples were obtained in this study. We identified 714 DEGs between the two groups, with 394 up-regulated and 320 down-regulated. Additionally, we identified 774 MPRGs, from which we derived 30 MPRDEGs by intersecting with DEGs, among which 21 exhibited interaction relationships. GO and KEGG analyses revealed the enrichment of MPRDEGs in five biological processes, five cell components, five molecular functions, and three biological pathways. Immune infiltration analysis indicated a strong positive correlation between activated nature killer (NK) cells and memory B cells, while neutrophils and monocytes showed the strongest negative correlation. Further investigation of MPRDEGs identified nine hub genes associated with 41 TFs, 82 miRNAs, and 44 drugs or molecular compounds. Additionally, qRT-PCR results demonstrated overexpression of the CD163, TREM1, and TREM2 genes in ovarian tissues from the PCOS group.

Conclusion

This study elucidated the polarization status and regulatory characteristics of macrophages in ovarian tissues of the PCOS subjects, confirming significant overexpression of CD163, TREM1, and TREM2. These findings contribute to a deeper understanding of the pathogenesis of PCOS.

From proteome to pathogenesis: investigating polycystic ovary syndrome with Mendelian randomization analysis

Background

Polycystic ovary syndrome (PCOS) is defined by oligo/anovulation, hyperandrogenism, and polycystic ovaries with uncertain pathogenesis. The proteome represents a substantial source of therapeutic targets, and their coding genes may elucidate the mechanisms underlying PCOS. However, reports on the profiles of the human plasma protein-coding genes and PCOS are limited. Here, we aimed to investigate novel biomarkers or drug targets for PCOS by integrating genetics and the human plasma proteome.

Methods

Our study acquired the protein quantitative trait loci from DECODE Genetics, offering 4,907 proteins in 35,559 individuals while obtaining PCOS summary statistics by accessing the FinnGen biobank (1,639 cases and 218,970 controls) and the genome-wide association study catalog (797 cases and 140,558 controls). Herein, we sequentially used two-sample Mendelian randomization (MR) analyses and colocalization to verify the causal link between candidate proteins, their coding genes, and PCOS. Further PCOS data download was conducted by accessing the Gene Expression Omnibus and Zenodo platforms. Gene expression level analysis, pathway enrichment analysis, immune cell infiltration, and transcription factor prediction were performed, aiming at detecting specific cell types with enriched expression and exploring potential optimized treatments for PCOS.

Results

MR analysis revealed 243 protein-coding genes with a causal relationship to PCOS risk, of which 12 were prioritized with the most significant evidence. Through colocalization analysis, three key genes, CUB domain-containing protein 1 (CDCP1), glutaredoxin 2 (GLRX2), and kirre-like nephrin family adhesion molecule 2 (KIRREL2), were identified. Subsequently, the three genes were strongly related to immune function and metabolism in terms of biological significance. In single-cell analysis, the expression levels of genes in ovarian theca cells were explored.

Conclusion

Overall, three protein-coding genes (CDCP1, GLRX2, and KIRREL2) may be related to a higher PCOS risk, suggesting that they may be entry points for exploration of PCOS pathogenesis and treatment, warranting further clinical investigations.

Integrated data driven analysis identifies potential candidate genes associated with PCOS

Polycystic ovary syndrome (PCOS) is one of the most common anovulatory disorder observed in women presenting with infertility. Several high and low throughput studies on PCOS have led to accumulation of vast amount of information on PCOS. Despite the availability of several resources which index the advances in PCOS, information on its etiology still remains inadequate. Analysis of the existing information using an integrated evidence based approach may aid identification of novel potential candidate genes with a role in PCOS pathophysiology. This work focuses on integrating existing information on PCOS from literature and gene expression studies and evaluating the application of gene prioritization and network analysis to predict missing novel candidates. Further, it assesses the utility of evidence-based scoring to rank genes for their association with PCOS. The results of this study led to identification of ∼2000 plausible candidate genes associated with PCOS. Insilico validation of these identified candidates confirmed the role of 938 genes in PCOS. Further, experimental validation was carried out for four of the potential candidate genes, a high-scoring (PROS1), two mid-scoring (C1QA and KNG1), and a low-scoring gene (VTN) involved in the complement and coagulation pathway by comparing protein levels in follicular fluid in women with PCOS and healthy controls. While the expression of PROS1, C1QA, and KNG1 was found to be significantly downregulated in women with PCOS, the expression of VTN was found to be unchanged in PCOS. The findings of this study reiterate the utility of employing insilico approaches to identify and prioritize the most promising candidate genes in diseases with a complex pathophysiology like PCOS. Further, the study also helps in gaining clearer insights into the molecular mechanisms associated with the manifestation of the PCOS phenotype by contributing to the existing repertoire of genes associated with PCOS.

DENND1A desensitizes granulosa cells to FSH by arresting intracellular FSHR transportation

Polycystic ovary syndrome (PCOS) is a complex disorder. Genome-wide association studies (GWAS) have identified several genes associated with this condition, including DENND1A. DENND1A encodes a clathrin-binding protein that functions as a guanine nucleotide exchange factor involved in vesicular transport. However, the specific role of DENND1A in reproductive hormone abnormalities and follicle development disorders in PCOS remain poorly understood. In this study, we investigated DENND1A expression in ovarian granulosa cells (GCs) from PCOS patients and its correlation with hormones. Our results revealed an upregulation of DENND1A expression in GCs from PCOS cases, which was positively correlated with testosterone levels. To further explore the functional implications of DENND1A, we generated a transgenic mouse model overexpressing Dennd1a (TG mice). These TG mice exhibited subfertility, irregular estrous cycles, and increased testosterone production following PMSG stimulation. Additionally, the TG mice displayed diminished responsiveness to FSH, characterized by smaller ovary size, less well-developed follicles, and abnormal expressions of FSH-priming genes. Mechanistically, we found that Dennd1a overexpression disrupted the intracellular trafficking of follicle stimulating hormone receptor (FSHR), promoting its internalization and inhibiting recycling. These findings shed light on the reproductive role of DENND1A and uncover the underlying mechanisms, thereby contributing valuable insights into the pathogenesis of PCOS and providing potential avenues for drug design in PCOS treatment.

Translocase of Outer Mitochondrial Membrane 40, as a Promising Biomarker for the Diagnosis of Polycystic Ovary Syndrome and Pan-Cancer

Polycystic ovary syndrome (PCOS) is a metabolic disease that affects the reproductive system, and its pathogenesis remains unresolved. Through the application of bioinformatics and molecular biology techniques, this study has identified a significant association between translocase of outer mitochondrial membrane 40 (TOMM40) and both PCOS and pan-cancers. The selection of PCOS biomarkers included TOMM40, which we found to be significantly decreased in the PCOS group both in vitro and in vivo, using molecular biology methods such as Western Blot as well as immunohistochemistry. Over-expression TOMM40 can rescue the effect on apoptosis rate and proliferation suppression induced by DHEA in KGN cells. TOMM40 as a biomarker for the diagnosis of PCOS. The pan-cancer analysis revealed an association between elevated TOMM40 expression in Uterine Corpus Endometrial Carcinoma and an unfavorable prognosis, while increased TOMM40 expression in six tumor types was linked to a favorable prognosis. Therefore, TOMM40 can be regarded as a promising biomarker for diagnosing both PCOS and pan-cancer.

Berberine alleviates inflammation in polycystic ovary syndrome by inhibiting hyaluronan synthase 2 expression

BACKGROUND

Polycystic ovary syndrome (PCOS) is a heterogeneous metabolic and endocrine disorder that causes anovulatory infertility and abnormal folliculogenesis in women of reproductive age. Several studies have revealed inflammation in PCOS follicles, and recent evidence suggests that Berberine (BBR) effectively reduces inflammatory responses in PCOS, however, the underlying mechanisms remain unclear.

PURPOSE

To determine the underlying mechanisms by which BBR alleviates inflammation in PCOS.

STUDY DESIGN

Primary human GCs from healthy women and women with PCOS, and KGN cells were used for in vitro studies. ICR mice were used for in vivo studies.

METHODS

Gene expression was measured using RT-qPCR. HAS2, inflammatory cytokines, and serum hormones were assayed by ELISA. Protein expression profiles were assayed by Western blot. Chronic low-grade inflammatory mouse models were developed by intraperitoneal injection with LPS, and PCOS mouse models were established by subcutaneous intraperitoneal injection of DHEA. BBR and 4-MU were administered by gavage. Ovarian morphologic changes were evaluated using H&E staining. HAS2 expression in the ovary was assayed using Western blot and immunohistochemistry.

RESULTS

Our results confirmed that HAS2 expression and hyaluronan (HA) accumulation are closely associated with inflammatory responses in PCOS. Data obtained from in vitro studies showed that HAS2 and inflammatory genes (e.g., MCP-1, IL-1β, and IL-6) are significantly upregulated in PCOS samples and LPS-induced KGN cells compared to their control groups. In addition, these effects were reversed by blocking HAS2 expression or HA synthesis using BBR or 4-MU, respectively. Furthermore, HAS2 overexpression induces the expression of inflammatory genes in PCOS. These results were further confirmed in LPS- and DHEA-induced mouse models, where inflammatory genes were reduced by BBR or 4-MU, and ovarian morphology was restored.

CONCLUSIONS

Our results define previously unknown links between HAS2 and chronic low-grade inflammation in the follicles of women with PCOS. BBR exerts its anti-inflammatory effects by down-regulating HAS2. This study provides a novel therapeutic target for alleviating ovarian inflammation in women with PCOS.

Comprehensive analysis of ovarian granulosa cell proteomics and phosphoproteomics in PCOS patients without insulin resistance

PCOS is a complex and heterogeneous metabolic disorder that affects 6-20% of women of reproductive age. However, research on phosphorylation modification proteomics in PCOS remains lacking. PCOS can be divided into two groups based on the presence or absence of insulin resistance: PCOS with insulin resistance (PCOS-IR) and PCOS non-insulin resistant (PCOS-NIR). This study focused on the group without insulin resistance. Twenty-one PCOS-NIR and 39 control-NIR (Ctrl-NIR) patients were included in this study. All participants underwent ICSI or IVF-embryo transfer (IVF-ET) treatment in a reproductive center from July 2020 to November 2020. During oocyte retrieval, fresh follicular fluid was aspirated, collected, and sent to the laboratory for analysis of the granulosa cells. A 4D-label-free proteome quantification method was performed in this study; this was used to analyze protein enzymatic peptide fragments by liquid chromatography-mass spectrometry (LC-MS). Bioinformatic analysis was performed on differentially expressed proteins (DEPs) and differentially phosphorylated proteins (DPPs). A total of 713 DEPs were identified between the two groups, including 293 upregulated and 420 downregulated DEPs in the PCOS-NIR group. There were 522 and 159 proteins with increased and decreased phosphorylation, respectively, in the PCOS-NIR group. After analyzing the different phosphorylation modification sites, 933 sites with upregulated and 211 sites with downregulated phosphorylation were found in the PCOS-NIR group. In this study, we describe the quantitative protein expression profiles and phosphorylation-modified protein expression profiles of ovarian granulosa cells from patients with PCOS-NIR, providing a new research perspective for these patients. Further studies are required to elucidate the role of protein phosphorylation in PCOS.

Inhibition of NLRP3 inflammasome-A potential mechanistic therapeutic for treatment of polycystic ovary syndrome?

This review article explores the relationship between the NOD-like receptor protein 3 (NLRP3) inflammasome and the risk of developing polycystic ovary syndrome (PCOS). The NLRP3 inflammasome, a fundamental element of the innate immune system, plays a crucial role in the production of proinflammatory mediators and pyroptosis, a type inflammatory cell death. We conducted a thorough search on scientific databases to gather relevant information on this topic, utilizing relevant keywords. The reviewed studies indicated a correlation between PCOS and a higher incidence of granulosa cell (GC) death and the presence of ovarian tissue fibrosis. NLRP3 inflammasome stimulation and subsequent pyroptosis in GCs play a significant role in the pathophysiology of PCOS. Active NLRP3 inflammasome is involved in the production of inflammatory mediators like interleukin-1β (IL-1β) and IL-18, contributing to the development of PCOS, particularly in overweight patients. Therefore, inhibiting NLRP3 activation and pyroptosis could potentially offer novel therapeutic strategies for PCOS. Some limited studies have explored the use of agents with antioxidant and anti-inflammatory properties, as well as gene therapy approaches, to target the NLRP3 and pyroptosis signaling pathways. This study overview the understanding of the relationship between NLRP3 inflammasome activation, pyroptosis, and PCOS. It highlights the potential of targeting the NLRP3 inflammasome as an approach for treating PCOS. Nonetheless, further research and clinical trials are imperative to validate these results and explore the effectiveness of NLRP3 inflammasome inhibition in the management of PCOS.

Induced Pluripotent Stem Cells as a Possible Approach for Exploring the Pathophysiology of Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine condition among women with pleiotropic sequelae possessing reproductive, metabolic, and psychological characteristics. Although the exact origin of PCOS is elusive, it is known to be a complex multigenic disorder with a genetic, epigenetic, and environmental background. However, the pathogenesis of PCOS, and the role of genetic variants in increasing the risk of the condition, are still unknown due to the lack of an appropriate study model. Since the debut of induced pluripotent stem cell (iPSC) technology, the ability of reprogrammed somatic cells to self-renew and their potential for multidirectional differentiation have made them excellent tools to study different disease mechanisms. Recently, researchers have succeeded in establishing human in vitro PCOS disease models utilizing iPSC lines from heterogeneous PCOS patient groups (iPSCPCOS). The current review sets out to summarize, for the first time, our current knowledge of the implications and challenges of iPSC technology in comprehending PCOS pathogenesis and tissue-specific disease mechanisms. Additionally, we suggest that the analysis of polygenic risk prediction based on genome-wide association studies (GWAS) could, theoretically, be utilized when creating iPSC lines as an additional research tool to identify women who are genetically susceptible to PCOS. Taken together, iPSCPCOS may provide a new paradigm for the exploration of PCOS tissue-specific disease mechanisms.

The PCOS-NAFLD Multidisease Phenotype Occurred in Medaka Fish Four Generations after the Removal of Bisphenol A Exposure

As a heterogeneous reproductive disorder, polycystic ovary syndrome (PCOS) can be caused by genetic, diet, and environmental factors. Bisphenol A (BPA) can induce PCOS and nonalcoholic fatty liver disease (NAFLD) due to direct exposure; however, whether these phenotypes persist in future unexposed generations is not currently understood. In a previous study, we observed that transgenerational NAFLD persisted in female medaka for five generations (F4) after exposure to an environmentally relevant concentration (10 μg/L) of BPA. Here, we demonstrate PCOS in the same F4 generation female medaka that developed NAFLD. The ovaries contained immature follicles, restricted follicular progression, and degenerated follicles, which are characteristics of PCOS. Untargeted metabolomic analysis revealed 17 biomarkers in the ovary of BPA lineage fish, whereas transcriptomic analysis revealed 292 genes abnormally expressed, which were similar to human patients with PCOS. Metabolomic-transcriptomic joint pathway analysis revealed activation of the cancerous pathway, arginine-proline metabolism, insulin signaling, AMPK, and HOTAIR regulatory pathways, as well as upstream regulators esr1 and tgf signaling in the ovary. The present results suggest that ancestral BPA exposure can lead to PCOS phenotypes in the subsequent unexposed generations and warrant further investigations into potential health risks in future generations caused by initial exposure to EDCs.

Evaluation of the p53 pathway in polycystic ovarian syndrome pathogenesis and apoptosis enhancement in human granulosa cells through transcriptome data analysis

The polycystic ovarian syndrome (PCOS) is closely associated with enhanced apoptosis of granulosa cells, which have a vital role in maturation of oocytes. p53 plays a critical role in the regulation of apoptosis and cell cycle arrest, metabolism and insulin resistance. The aim of this study was to investigate the impact of p53 pathway in enhancing apoptosis and abnormal function of granulosa cells. In this study, microarray analysis and RNA sequencing were downloaded from the GEO and used as datasets. Principal Component Analysis (PCA) and online SSizer tool were applied to evaluate the experiment quality control and sample sufficiency, respectively. Bioinformatics' analyses were performed on the selected datasets, and validated by qRT-PCR and western blot analyses. Three datasets out of five ones were chosen for re-analyzing based on the PCA outcomes. 21 deregulated genes were identified via filters including p < 0.05 and |log2FC|≥ 1. Functional enrichment analysis confirmed the relevance of cell cycle regulation and apoptosis as common biological hallmarks in PCOS. Results have shown differentially expressed p53 target genes involved in apoptosis (BAX, FAS, PMAIP1, and CASP8), cell cycle (Cyclins, Cyclin dependent kinases), glucose metabolism and insulin resistance (THBS1), and p53 regulation (MDM2). Subsequently, the relative mRNA expression of FAS, PMAIP1 and MDM2 genes, and protein levels of p53 and MDM2 were confirmed using granulosa cells collected from 20 PCOS women and 18 control individuals by qRT-PCR and western blot, respectively. Results of this study represent the possible role of p53 pathway in pathogenesis of PCOS particularly, through the enhancement of apoptosis in granulosa cells.

Identification of the hub genes in polycystic ovary syndrome based on disease-associated molecule network

Revealing the key genes involved in polycystic ovary syndrome (PCOS) and elucidating its pathogenic mechanism is of extreme importance for the development of targeted clinical therapy for PCOS. Investigating disease by integrating several associated and interacting molecules in biological systems will make it possible to discover new pathogenic genes. In this study, an integrative disease-associated molecule network, combining protein-protein interactions and protein-metabolites interactions (PPMI) network was constructed based on the PCOS-associated genes and metabolites systematically collected. This new PPMI strategy identified several potential PCOS-associated genes, which have unreported in previous publications. Moreover, the systematic analysis of five benchmarks data sets indicated the DERL1 was identified as downregulated in PCOS granulosa cell and has good classification performance between PCOS patients and healthy controls. CCR2 and DVL3 were upregulated in PCOS adipose tissues and have good classification performance. The expression of novel gene FXR2 identified in this study is significantly increased in ovarian granulosa cells of PCOS patients compared with controls via quantitative analysis. Our study uncovers substantial differences in the PCOS-specific tissue and provides a plethora of information on dysregulated genes and metabolites that are linked to PCOS. This knowledgebase could have the potential to benefit the scientific and clinical community. In sum, the identification of novel gene associated with PCOS provides valuable insights into the underlying molecular mechanisms of PCOS and could potentially lead to the development of new diagnostic and therapeutic strategies.

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.

TGF-β1 upregulates secreted protein acidic and rich in cysteine expression in human granulosa-lutein cells: a potential mechanism for the pathogenesis of ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a serious complication during in vitro fertilization (IVF) treatment. The upregulation of ovarian transforming growth factor-beta 1 (TGF-β1) is involved in the development of OHSS. The secreted protein acidic and rich in cysteine (SPARC) is a secreted multifunctional matricellular glycoprotein. Although the regulatory effects of TGF-β1 on SPARC expression have been reported, whether TGF-β1 regulates SPARC expression in the human ovary remains unknown. In addition, the role of SPARC in the pathogenesis of OHSS is unclear.

METHODS

A steroidogenic human ovarian granulosa-like tumor cell line, KGN, and primary culture of human granulosa-lutein (hGL) cells obtained from patients undergoing IVF treatment were used as experimental models. OHSS was induced in rats, and ovaries were collected. Follicular fluid samples were collected from 39 OHSS and 35 non-OHSS patients during oocyte retrieval. The underlying molecular mechanisms mediating the effect of TGF-β1 on SPARC expression were explored by a series of in vitro experiments.

RESULTS

TGF-β1 upregulated SPARC expression in both KGN and hGL cells. The stimulatory effect of TGF-β1 on SPARC expression was mediated by SMAD3 but not SMAD2. The transcription factors, Snail and Slug, were induced in response to the TGF-β1 treatment. However, only Slug was required for the TGF-β1-induced SPARC expression. Conversely, we found that the knockdown of SPARC decreased Slug expression. Our results also revealed that SPARC was upregulated in the OHSS rat ovaries and in the follicular fluid of OHSS patients. Knockdown of SPARC attenuated the TGF-β1-stimulated expression of vascular endothelial growth factor (VEGF) and aromatase, two markers of OHSS. Moreover, the knockdown of SPARC reduced TGF-β1 signaling by downregulating SMAD4 expression.

CONCLUSIONS

By illustrating the potential physiological and pathological roles of TGF-β1 in the regulation of SPARC in hGL cells, our results may serve to improve current strategies used to treat clinical infertility and OHSS. Video Abstract.

Gonadotropins as pharmacological agents in assisted reproductive technology and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy associated with subfertility/infertility and pregnancy complications. Most PCOS women opt for assisted reproductive technologies (ART) for successful conception; however, optimization of the relative doses of the gonadotropins [follicle-stimulating hormone (FSH), luteinizing hormone (LH)/human chorionic gonadotropin (hCG)] for appropriate steroidogenesis, without causing ovarian hyperstimulatory syndrome (OHSS), is challenging. Embryonic factors probably do not contribute to pregnancy loss in PCOS women, albeit hormonal imbalance impairs the metabolic microenvironment critical for oocyte maturation and endometrial receptivity. Certain clinical studies have confirmed the role of metabolic corrections in increasing the rate of pregnancy in PCOS women. This review focuses on the impact of untimely high LHCGR and/or LH levels on oocyte/embryo quality, pregnancy outcomes in ART, and exploring LHCGR as a potential drug target in PCOS women.

Upregulation of TXNIP contributes to granulosa cell dysfunction in polycystic ovary syndrome via activation of the NLRP3 inflammasome

Polycystic ovary syndrome (PCOS) is a complex endocrine disease. Thioredoxin-interacting protein (TXNIP) promotes oxidative stress and triggers inflammation. Herein, we investigated the role and potential mechanism of TXNIP in PCOS. In a mouse model of dehydroepiandrosterone (DHEA)-induced PCOS, we found that TXNIP was upregulated in the ovaries, especially in granulosa cells (GCs). TXNIP was also upregulated in testosterone (T)-treated GCs in vitro. Knockdown of TXNIP by lentivirus-constructed shRNA attenuated T-induced GC injury and oxidative stress, as well as inflammation and the NLRP3 inflammasome. The mechanism by which TXNIP promotes inflammation may involve TXNIP dissociation from the TXNIP-TRX complex and binding to NLRP3 to form the inflammasome. Additionally, we verified that knockdown of TXNIP ameliorated ovarian injury and inflammation in mice with DHEA-induced PCOS in vivo. Collectively, we demonstrated that TXNIP is involved in GC inflammation by promoting NLRP3 inflammasome activation in PCOS.

Cumulus Cell Transcriptome after Cumulus-Oocyte Complex Exposure to Nanomolar Cadmium in an In Vitro Animal Model of Prepubertal and Adult Age

Cadmium (Cd), a highly toxic pollutant, impairs oocyte fertilization, through oxidative damage on cumulus cells (CCs). This study analysed the transcriptomic profile of CCs of cumulus-oocyte complexes (COCs) from adult and prepubertal sheep, exposed to Cd nanomolar concentration during in vitro maturation. In both age-groups, CCs of matured oocytes underwent RNA-seq, data analysis and validation. Differentially expressed genes (DEGs) were identified in adult (n = 99 DEGs) and prepubertal (n = 18 DEGs) CCs upon Cd exposure. Transcriptomes of adult CCs clustered separately between Cd-exposed and control samples, whereas prepubertal ones did not as observed by Principal Component Analysis. The transcriptomic signature of Cd-induced CC toxicity was identified by gene annotation and literature search. Genes associated with previous studies on ovarian functions and/or Cd effects were confirmed and new genes were identified, thus implementing the knowledge on their involvement in such processes. Enrichment and validation analysis showed that, in adult CCs, Cd acted as endocrine disruptor on DEGs involved in hormone biosynthesis, cumulus expansion, regulation of cell signalling, growth and differentiation and oocyte maturation, whereas in prepubertal CCs, Cd affected DEGs involved in CC development and viability and CC-oocyte communications. In conclusion, these DEGs could be used as valuable non-invasive biomarkers for oocyte competence.

Granulosa cells from immature follicles exhibit restricted glycolysis and reduced energy production: a dominant problem in polycystic ovary syndrome

PURPOSE

We hypothesized that immature oocytes are associated with impaired energy production in surrounding granulosa cells (GCs) in polycystic ovary syndrome (PCOS). Thus, this study investigated mitochondrial function, determined expression of glycolytic regulatory enzymes, and measured ATP levels in GCs of PCOS patients.

METHODS

GCs were isolated from forty-five PCOS patients and 45 control women. Intracellular concentration of reactive oxygen species (ROS), mitochondrial membrane potential (Δψm), the rate of glycolysis, total antioxidant capacity (TAC), activities of catalase (CAT) and superoxide dismutase (SOD), and ATP level were measured in GCs. The gene expression and protein levels of glycolytic enzymes (hexokinase, muscular phosphofructokinase, platelet derived phosphofructokinase, and muscular pyruvate kinase) were determined. Association of GC energy level with oocyte maturation was further validated by measuring glycolysis rate and ATP level in GCs isolated from mature and immature follicles from new set of fifteen PCOS patients and 15 controls.

RESULTS

PCOS patients showed higher ROS level, decreased TAC, reduced CAT and SOD activities, and lower Δψm together with reduced expression of key glycolytic enzymes. ATP concentration and biochemical pregnancy were lower in PCOS compared with control group. ATP levels were found to be significantly correlated with ROS and Δψm (r = - 0.624 and r = 0.487, respectively). GCs isolated from immature follicles had significantly lower ATP levels and rate of glycolysis compared with the GCs separated from mature follicles in both PCOS patients and control.

CONCLUSION

Declined energy due to the mitochondrial dysfunction and restrained glycolysis in GCs is associated with the immature oocytes and lower biochemical pregnancy in PCOS.

Systems biology and in silico-based analysis of PCOS revealed the risk of metabolic disorders

Background

Polycystic ovarian syndrome (PCOS) is a common condition of hyperandrogenism, chronic ovulation, and polycystic ovaries in females during the reproduction and maturation of the ovum. Although PCOS has been associated with metabolic disorders, including type 2 diabetes (T2D), obesity (OBE), and cardiovascular disease (CVD), Causal connection and molecular features are still unknown.

Purpose

Therefore, we investigated the shared common differentially expressed genes (DEGs), pathways, and networks of associated proteins in PCOS and metabolic diseases with therapeutic intervention.

Methods

We have used a bioinformatics pipeline to analyze transcriptome data for the polycystic ovarian syndrome (PCOS), type 2 diabetes (T2D), obesity (OBE), and cardiovascular diseases (CVD) in female patients. Then we employed gene-disease association network, gene ontology (GO) and signaling pathway analysis, selection of hub genes from protein-protein interaction (PPI) network, molecular docking, and gold benchmarking approach to screen potential hub proteins.

Result

We discovered 2225 DEGs in PCOS patients relative to healthy controls and 34, 91, and 205 significant DEGs with T2D, Obesity, and CVD, respectively. Gene Ontology analysis revealed several significant shared and metabolic pathways from signaling pathway analysis. Furthermore, we identified ten potential hub proteins from PPI analysis that may serve as a therapeutic intervention in the future. Finally, we targeted one significant hub protein, IGF2R (PDB ID: 2V5O), out of ten hub proteins based on the Maximal clique centrality (MCC) algorithm and literature review for molecular docking study. Enzastaurin (-12.5), Kaempferol (-9.1), Quercetin (-9.0), and Coumestrol (-8.9) kcal/mol showed higher binding affinity in the molecular docking approach than 19 drug compounds. We have also found that the selected four compounds displayed favorable ADMET properties compared to the native ligand.

Conclusion

Our in-silico research findings identified a shared molecular etiology between PCOS and metabolic diseases that may suggest new therapeutic targets and warrants future experimental validation of the key targets.

Bioinformatics searching of diagnostic markers and immune infiltration in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases in reproductive-aged women, and it affects numerous women worldwide. This study aimed to identify potential diagnostic markers and explore the infiltration of immune cells in PCOS, contributing to the development of potential therapeutic drugs for this disease. We identified five key genes: CBLN1 (AUC = 0.924), DNAH5 (AUC = 0.867), HMOX1 (AUC = 0.971), SLC26A8 (AUC = 0,933), and LOC100507250 (AUC = 0.848) as diagnostic markers of PCOS. Compared with paired normal group, naïve B cells, gamma delta T cells, resting CD4 memory T cells, and activated CD4 memory T cells were significantly decreased in PCOS while M2 macrophages were significantly increased. Significant correlations were presented between the five key genes and the components of immune infiltrate. The results of CMap suggest that four drugs, ISOX, apicidin, scriptaid, and NSC-94258, have the potential to reverse PCOS. The present study helps provide novel insights for the prevention and treatment of PCOS, and immune cell infiltration plays a role that cannot be ignored in the occurrence and progression of the disease.

Tyrosine phosphatase SHP2 in ovarian granulosa cells balances follicular development by inhibiting PI3K/AKT signaling

In mammals, the growth and maturation of oocytes within growing follicles largely depends on ovarian granulosa cells (GCs) in response to gonadotropin stimulation. Many signals have been shown to regulate GC proliferation and apoptosis. However, whether the tyrosine phosphatase SHP2 is involved remains unclear. In this study, we identified the crucial roles of SHP2 in modulating GC proliferation and apoptosis. The production of both mature oocytes and pups was increased in mice with Shp2 specifically deleted in ovarian GCs via Fshr-Cre. Shp2 deletion simultaneously promoted GC proliferation and inhibited GC apoptosis. Furthermore, Shp2 deficiency promoted, while Shp2 overexpression inhibited, the proliferation of cultured primary mouse ovarian GCs and the human ovarian granulosa-like tumor cell line KGN in vitro. Shp2 deficiency promoted follicule-stimulating hormone (FSH)-activated phosphorylation of AKT in vivo. SHP2 deficiency reversed the inhibitory effect of hydrogen peroxide (H2O2) on AKT activation in KGN cells. H2O2 treatment promoted the interaction between SHP2 and the p85 subunit of PI3K in KGN cells. Therefore, SHP2 in GCs may act as a negative modulator to balance follicular development by suppressing PI3K/AKT signaling. The novel function of SHP2 in modulating proliferation and apoptosis of GCs provides a potential therapeutic target for the clinical treatment of follicle developmental dysfunction.

Candidate genes for infertility: an in-silico study based on cytogenetic analysis

Background

The cause of infertility remains unclear in a significant proportion of reproductive-age couples who fail to conceive naturally. Chromosomal aberrations have been identified as one of the main genetic causes of male and female infertility. Structural chromosomal aberrations may disrupt the functioning of various genes, some of which may be important for fertility. The present study aims to identify candidate genes and putative functional interaction networks involved in male and female infertility using cytogenetic data from cultured peripheral blood lymphocytes of infertile patients.

Methods

Karyotypic analyses was done in 201 infertile patients (100 males and 101 females) and 201 age and gender matched healthy controls (100 males and 101 females) after 72 h peripheral lymphocyte culturing and GTG banding, followed by bioinformatic analysis using Cytoscape v3.8.2 and Metascape.

Results

Several chromosomal regions with a significantly higher frequency of structural aberrations were identified in the infertile males (5q2, 10q2, and 17q2) and females (6q2, 16q2, and Xq2). Segregation of the patients based on type of infertility (primary v/s secondary infertility) led to the identification of chromosomal regions with a significantly higher frequency of structural aberrations exclusively within the infertile males (5q2, 17q2) and females (16q2) with primary infertility. Cytoscape identified two networks specific to these regions: a male specific network with 99 genes and a female specific network with 109 genes. The top enriched GO terms within the male and female infertility networks were “skeletal system morphogenesis” and “mRNA transport” respectively. PSME3, PSMD3, and CDC27 were the top 3 hub genes identified within the male infertility network. Similarly, UPF3B, IRF8, and PSMB1 were the top 3 hub genes identified with the female infertility network. Among the hub genes identified in the male- and female-specific networks, PSMB1, PSMD3, and PSME3 are functional components of the proteasome complex. These hub genes have a limited number of reports related to their respective roles in maintenance of fertility in mice model and humans and require validation in further studies.

Conclusion

The candidate genes predicted in the present study can serve as targets for future research on infertility.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01320-x.

Notch Signaling Induced by Endoplasmic Reticulum Stress Regulates Cumulus-Oocyte Complex Expansion in Polycystic Ovary Syndrome

Endoplasmic reticulum (ER) stress activated in granulosa cells contributes to the pathophysiology of polycystic ovary syndrome (PCOS). In addition, recent studies have demonstrated that Notch signaling plays multiple roles in the ovary via cell-to-cell interactions. We hypothesized that ER stress activated in granulosa cells of antral follicles in PCOS induces Notch signaling in these cells, and that activated Notch signaling induces aberrant cumulus-oocyte complex (COC) expansion. Expression of Notch2 and Notch-target transcription factors was increased in granulosa cells of PCOS patients and model mice. ER stress increased expression of Notch2 and Notch-target transcription factors in cultured human granulosa-lutein cells (GLCs). Inhibition of Notch signaling abrogated ER stress-induced expression of genes associated with COC expansion in cultured human GLCs, as well as ER stress-enhanced expansion of cumulus cells in cultured murine COCs. Furthermore, inhibition of Notch signaling reduced the areas of COCs in PCOS model mice with activated ER stress in the ovary, indicating that Notch signaling regulates COC expansion in vivo. Our findings suggest that Notch2 signaling is activated in granulosa cells in PCOS and regulates COC expansion. It remains to be elucidated whether aberrant COC expansion induced by the ER stress-Notch pathway is associated with ovulatory dysfunction in PCOS patients.

Family history of menstrual irregularity or diabetes mellitus enhances the susceptibility to polycystic ovary syndrome among subjects harboring rs7903146 genetic variant of TCF7L2

Purpose

TCF7L2 mediated Wnt signaling cascade regulates glucose homeostasis by orchestrating expression, processing, and hepatic clearance of insulin. Type 2 diabetes mellitus (T2DM) and polycystic ovary syndrome (PCOS) significantly overlap in pathophysiological features with insulin resistance as a central driver. While TCF7L2 is the most potent T2DM locus, studies on the association of TCF7L2 with PCOS are limited and inconclusive. Therefore, in addition to expression profiling, the association of TCF7L2 polymorphic variant rs7903146 with PCOS was evaluated.

Methods

Using Rotterdam-2003 criteria for the diagnosis, 120 PCOS cases, and 120 age-matched controls were recruited. Subjects underwent clinical, biochemical, and hormonal assessment, followed by genotyping for rs7903146, carried out by PCR-RFLP and TCFL2 expression profiling by qRT-PCR. Genotype-phenotype correlation analysis was performed to evaluate any such associations. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were computed by conditional logistic regression.

Results

Higher odds of developing PCOS were observed in the women having a family history (FH) of either T2DM (OR = 3.86, 95% CI:1.90 - 7.83), hirsutism (OR = 4.74. 95%CI: 1.91 - 17.21) or menstrual irregularities (MI) (OR = 3.07, 95%CI: 1.61 - 8.54). The genotypes of rs7903146 did not confer any risk for developing PCOS (OR = 0.46;95%CI: 0.15 - 2.03). However, the elevated risk was seen in the subjects who harbored the variant allele and had FH of either T2DM (OR = 6.71; 95%CI: 1.89 - 23.78) or MI (OR = 9.71; 95% CI:1.89 - 23.78).

Conclusion

TCF7L2 polymorphic variant rs7903146 is not independently linked to PCOS risk, but modulates the risk in the subjects having a family history of either T2DM or MI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01050-y.

The interactions of CAP and LYN with the insulin signaling transducer CBL play an important role in polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a hormonal disorder characterized by hyperandrogenism, ovulatory dysfunction, and insulin resistance. Evidence suggests that aberrations in insulin signaling-associated pathways may underlie PCOS pathogenesis. Our aim was to investigate the molecular mechanisms underlying PCOS and associated insulin resistance using in silico analyses, in vitro cell models, and in vivo murine models.

METHODS

R-based bioinformatics analysis was performed on granulosa cell microarray data from three human cohorts: healthy control, PCOS patients without insulin resistance, and PCOS patients with insulin resistance. Transgenic human granulosa cell models were utilized for in vitro studies. Transgenic murine models of dehydroepiandrosterone (DHEA)-induced PCOS were utilized for in vivo studies.

RESULTS

Sorbin and SH3 Domain Containing 1 (SORBS1), the parent gene of the insulin receptor-associated Casitas B-lineage lymphoma protein (CBL)-associated protein (CAP), is a key downregulated gene in PCOS patients with insulin resistance. CAP binding to CBL reduced CBL^Y731 phosphorylation, CBL-phosphoinositide 3-kinase (PI3K) p85α interactivity, protein kinase B (Akt)^S473 phosphorylation, and NFκB-induced inflammatory marker expression but enhanced CRKII-mediated membrane GLUT4 translocation in granulosa cells. In contrast, the tyrosine kinase Lck/Yes-Related Novel Protein (LYN) is upregulated in PCOS patients with insulin resistance. LYN binding to CBL enhanced CBL^Y731 phosphorylation, CBL-PI3K p85α interactivity, Akt^S473 phosphorylation, and NFκB-induced inflammatory marker expression but did not impact membrane GLUT4 translocation. In PCOS mice, Cap overexpression, Cap transactivation by metformin, or enhancing Cbl-CrkII binding improved insulin sensitivity and ovarian dysfunction (i.e., estrous cycle disruption, cyst-like follicle formation, and sex hormone dysregulation). In contrast, Lyn knockdown, Lyn inhibition by PP2, or CBL-PI3K p85α blockade improved only ovarian dysfunction. Cbl^3YF phosphomutant overexpression (which enhances Cbl-CrkII binding but blocks Cbl-PI3K p85α binding) ameliorated both ovarian dysfunction and insulin resistance.

CONCLUSIONS

The interactions of CAP and LYN with CBL, and the resulting effects on CBL phosphorylation and activity, may play an important role in PCOS pathogenesis. Targeting these players may be a viable therapeutic strategy for PCOS.

Key Genes Associated With Non-Alcoholic Fatty Liver Disease and Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the most common metabolic and endocrinopathies disorder in women of reproductive age and non-alcoholic fatty liver (NAFLD) is one of the most common liver diseases worldwide. Previous research has indicated potential associations between PCOS and NAFLD, but the underlying pathophysiology is still not clear. The present study aims to identify the differentially expressed genes (DEGs) between PCOS and NAFLD through the bioinformatics method, and explore the associated molecular mechanisms. Methods: The microarray datasets GSE34526 and GSE63067 were downloaded from Gene Expression Omnibus (GEO) database and analyzed to obtain the DEGs between PCOS and NAFLD with the GEO2R online tool. Next, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for the DEGs were performed. Then, the protein-protein interaction (PPI) network was constructed and the hub genes were identified using the STRING database and Cytoscape software. Finally, NetworkAnalyst was used to construct the network between the targeted microRNAs (miRNAs) and the hub genes. Results: A total of 52 genes were identified as DEGs in the above two datasets. GO and KEGG enrichment analysis indicated that DEGs are mostly enriched in immunity and inflammation related pathways. In addition, nine hub genes, including TREM1, S100A9, FPR1, NCF2, FCER1G, CCR1, S100A12, MMP9, and IL1RN were selected from the PPI network by using the cytoHubba and MCODE plug-in. Then, four miRNAs, including miR-20a-5p, miR-129-2-3p, miR-124-3p, and miR-101-3p, were predicted as possibly the key miRNAs through the miRNA-gene network construction. Conclusion: In summary, we firstly constructed a miRNA-gene regulatory network depicting interactions between the predicted miRNA and the hub genes in NAFLD and PCOS, which provides novel insights into the identification of potential biomarkers and valuable therapeutic leads for PCOS and NAFLD.

Ovarian granulosa cells from women with PCOS express low levels of SARS-CoV-2 receptors and co-factors

Purpose

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is global pandemic with more than 5 million deaths so far. Female reproductive tract organs express coronavirus-associated receptors and factors (SCARFs), suggesting they may be susceptible to SARS-CoV-2 infection; however, the susceptibility of ovary/follicle/oocyte to the same is still elusive. Co-morbidities like obesity, type-2 diabetes mellitus, cardiovascular disease, etc. increase the risk of SARS-CoV-2 infection. These features are common in women with polycystic ovary syndrome (PCOS), warranting further scope to study SCARFs expression in ovary of these women.

Materials and methods

SCARFs expression in ovary and ovarian tissues of women with PCOS and healthy women was explored by analyzing publically available microarray datasets. Transcript expressions of SCARFs were investigated in mural and cumulus granulosa cells (MGCs and CGCs) from control and PCOS women undergoing in vitro fertilization (IVF).

Results

Microarray data revealed that ovary expresses all genes necessary for SARS-CoV-2 infection. PCOS women mostly showed down-regulated/unchanged levels of SCARFs. MGCs and CGCs from PCOS women showed lower expression of receptors ACE2, BSG and DPP4 and protease CTSB than in controls. MGCs showed lower expression of protease CTSL in PCOS than in controls. Expression of TMPRSS2 was not detected in both cell types.

Conclusion

Human ovarian follicle may be susceptible to SARS-CoV-2 infection. Lower expression of SCARFs in PCOS indicates that the risk of SARS-CoV-2 infection to the ovary may be lesser in these women than controls. This knowledge may help in safe practices at IVF settings in the current pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-022-06567-4.

LINC00173 regulates polycystic ovarian syndrome progression by promoting apoptosis and repressing proliferation in ovarian granulosa cells via the microRNA-124-3p (miR-124-3p)/jagged canonical Notch ligand 1 (JAG1) pathway

As an endocrine and metabolic disorder, polycystic ovarian syndrome (PCOS) is common in females at childbearing age. Our work was intended to uncover the underlying role of LINC00173 and its potential regulatory mechanism in PCOS based on two cell lines (PCOS granulosa cells and KGN cells) and an in vivo model established from Sprague Dawley rats. It was revealed that LINC00173 and JAG1 expressions were upregulated, while miR-124-3p was poorly expressed in PCOS patients and PCOS rats. Functional assays showed that LINC00173 overexpression repressed proliferation and stimulated apoptosis in granulosa cells and KGN cells, while LINC00173 downregulation exhibited the opposite effects. Besides, it was verified that LINC00173 upregulated JAG1 expression in KGN cells via competitively binding to miR-124-3p. Similarly, miR-124-3p abundance was inversely related to LINC00173 and JAG1 level in PCOS. Subsequently, rescue assays elucidated that miR-124-3p upregulation or downregulation eliminated the effects on KGN cell proliferation and apoptosis mediated by LINC00173 overexpression or knockdown. In addition, it was found that the JAG1 level in KGN cells was adversely modulated by miR-124-3p and positively modulated by LINC00173. Moreover, it was further demonstrated that the reduced cell vitality and increased apoptosis of KGN cells induced by overexpressing LINC00173 could be relieved by JAG1 deletion. These findings suggested that LINC00173 could be a latent regulating factor for PCOS progression via modulating the miR-124-3p/JAG1 cascade.

Identification of key genes associated with polycystic ovary syndrome (PCOS) and ovarian cancer using an integrated bioinformatics analysis

BACKGROUND

Accumulating evidence suggests a strong association between polycystic ovary syndrome (PCOS) and ovarian cancer (OC), but the potential molecular mechanism remains unclear. In this study, we identified previously unrecognized genes that are significantly correlated with PCOS and OC via bioinformatics.

MATERIALS AND METHODS

Multiple bioinformatic analyses, such as differential expression analysis, univariate Cox analysis, functional and pathway enrichment analysis, protein-protein interaction (PPI) network construction, survival analysis, and immune infiltration analysis, were utilized. We further evaluated the effect of OGN on FSHR expression via immunofluorescence.

RESULTS

TCGA-OC, GSE140082 (for OC) and GSE34526 (for PCOS) datasets were downloaded. Twelve genes, including RNF144B, LPAR3, CRISPLD2, JCHAIN, OR7E14P, IL27RA, PTPRD, STAT1, NR4A1, OGN, GALNT6 and CXCL11, were identified as signature genes. Drug sensitivity analysis showed that OGN might represent a hub gene in the progression of PCOS and OC. Experimental analysis found that OGN could increase FSHR expression, indicating that OGN could regulate the hormonal response in PCOS and OC. Furthermore, correlation analysis indicated that OGN function might be closely related to m6A and ferroptosis.

CONCLUSIONS

Our study identified a 12-gene signature that might be involved in the prognostic significance of OC. Furthermore, the hub gene OGN represent a significant gene involved in OC and PCOS progression by regulating the hormonal response.

Exploration of molecular features of PCOS with different androgen levels and immune-related prognostic biomarkers associated with implantation failure

BACKGROUND

Polycystic ovary syndrome (PCOS), the most common heterogeneous reproductive disease afflicting women of childbearing age, has been recognized as a chronic inflammatory disease recently. Most PCOS patients have hyperandrogenism, indicating a poor prognosis and poor pregnancy outcomes. The molecular mechanism underlying PCOS development is still unknown. In the present study, we investigated the gene expression profiling characteristics of PCOS with hyperandrogenism (HA) or without hyperandrogenism (NHA) and identified immune-related factors that correlated with embryo implantation failure.

METHODS

PCOS and recurrent implantation failure (RIF) microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. ClueGO software was used to perform enrichment analysis of differentially expressed genes (DEGs) in PCOS with varying androgen levels. The Weighted Co-Expression Network Analysis (WGCNA) was used to identify co-expressed modules and shared gene signatures between HA PCOS and RIF. Moreover, the upregulated DEGs of HA PCOS and RIF were intersected with shared gene signatures screening by WGCNA to excavate further key prognostic biomarkers related to implantation failure of HA PCOS. The selected biomarker was verified by qRT-PCR.

RESULTS

A total of 271 DEGs were found in HA PCOS granulosa cell samples, and 720 DEGs were found in NHA PCOS. According to CuleGO enrichment analysis, DEGs in HA PCOS are enriched in immune activation and inflammatory response. In contrast, DEGs in NHA PCOS are enriched in mesenchymal cell development and extracellular space. Using WGCNA analysis, we discovered 26 shared gene signatures between HA PCOS and RIF, which were involved in corticosteroid metabolism, bone maturation and immune regulation. DAPK2 was furtherly screened out and verified to be closely related with the development of HA PCOS, acting as an independent predictor biomarker of the embryo implantation failure. DAPK2 expression was negatively correlated to the embryo implantation rate (r=-0.474, P=0.003). The immune infiltration results suggested that upregulated DAPK2 expression was closely related with NK cell infiltration and macrophage M2, playing an essential role in the pathogenesis of implantation failure in HA PCOS.

CONCLUSION

Our research revealed the expression profiling of PCOS with different androgen levels and identified DAPK2 as a critical prognostic biomarker for implantation failure in PCOS.

WGCNA Analysis Identifies Polycystic Ovary Syndrome-Associated Circular RNAs That Interact with RNA-Binding Proteins and Sponge miRNAs

Objective

Dysfunction of cumulus granulosa cells has been suggested as a contributor to abnormal folliculogenesis and the development of polycystic ovary syndrome (PCOS), but the underlying molecular mechanisms remain unclear. Recent studies indicate that circular RNAs (circRNAs) exert important roles for diseases. We aimed to screen crucial circRNAs of PCOS patients and predict their functions.

Methods

The high-throughput datasets of circRNAs (GSE145296), microRNAs (miRNAs; GSE72274) and messenger RNAs (mRNAs; GSE155489) in cumulus cells of PCOS patients and controls were collected from the Gene Expression Omnibus database. Differentially expressed circRNAs (DECs), miRNAs (DEMs) and protein-coding genes (DEGs) were identified by the limma method. The weighted correlation network analysis (WGCNA) was conducted using the DECs to mine PCOS-associated modules. Hub DECs in modules were defined as both of |gene significance| and |module membership| >0.8. The downstream effectors of hub DECs were predicted by constructing DEC-DEM-DEG ceRNA and DEC-RNA binding protein (RBP) networks. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to explore the functions of circRNAs.

Results

A total of 3614 DECs, 3544 DEGs and 1469 DEMs were identified between PCOS and controls. WGCNA analysis yielded five PCOS-related modules, of which 190 DECs were hub circRNAs. Seventeen hub DECs, nine DEMs, and 315 DEGs were identified to construct the ceRNA network, while 56 hub DECs and two DEGs (MBNL2, RBPMS) constituted the circRNA-RBP network. Five hub DECs (hsa_circ_0063309, hsa_circ_0054275, hsa_circ_0056196, hsa_circ_0018108 and hsa_circ_0070987) were overlapped between ceRNA and DEC-MBNL2 regulatory networks and thus they may be pivotal for PCOS. Furthermore, hsa_circ_0099109 could interact with the RBP gene RBPMS. Function analyses showed these circRNAs were inflammation-, apoptosis- or steroidogenesis-related.

Conclusion

Aberrant expression of six circRNAs that function as RBP regulators or miRNA sponges may be possible mechanisms underlying the pathogenesis of PCOS by affecting apoptosis and steroidogenesis in cumulus cells.

LRH-1 high expression in the ovarian granulosa cells of PCOS patients

PURPOSE

Polycystic ovary syndrome (PCOS) is considered one of the most common endocrine disorders with heterogeneity. There are also reports that liver receptor homolog 1 [LRH-1 or nuclear receptor subfamily 5 group A member 2] plays an important role in the reproductive system. But up to now, there are no reports related to the link with PCOS and LRH-1. In this study, we aimed to detect the LRH-1 expression in the ovarian granulosa cell (GC) of PCOS patients and explore the potential relationship between LRH-1 and PCOS.

METHODS

In all, 146 follicular fluid samples were collected in this study, including 72 from PCOS patients and 74 from control patients who underwent intracytoplasmic sperm injection or in vitro fertilization-embryo transfer. The ovarian GCs were extracted from the patient's follicular fluid by magnetic-activated cell sorting method, and real-time quantitative PCR was used to measure the expression of LRH-1 in ovarian GCs. Then we analyzed the correlation between the expression level of LRH-1 and the clinical characteristics of the patient by using Pearson Correlation analysis.

RESULTS

The expression of LRH-1 was significantly higher in PCOS patients ovarian GCs than that in the control patients [(1.38 ± 0.47) vs (1.03 ± 0.32), t = 5.327, p < 0.0001], and it was positively correlated with antral follicles counting (r = 0.3607, p < 0.0001) and the serum anti-Mullerian hormone (r = 0.2662, p = 0.0012), luteotropic hormone (r = 0.2518, p = 0.0022), testosterone (r = 0.2794, p = 0.0006) in all patients. No statistical significance between LRH-1 and body mass index, follicle-stimulating hormone, homeostasis model assessment of insulin resistance, dehydroepiandrosterone sulfate, progesterone.

CONCLUSIONS

Compared with the control group, we found that LRH-1 was highly expressed in the ovarian GCs of PCOS patients. Our study has revealed the relationship between the LRH-1 expression and PCOS, which suggested that LRH-1 may play an important role in ovulation disorders. While this finding provided new ideas for the study of pathogenesis, it also provided a theoretical basis for the clinical diagnosis and treatment for PCOS.

MiR-1224-5p attenuates polycystic ovary syndrome through inhibiting NOD-like receptor protein 3 inflammasome activation via targeting Forkhead box O 1

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that poses a great threat to women's health. MiR-1224-5p is downregulated in the follicular fluid of patients with PCOS, but its role remains largely unknown. In this study, mice were treated with dehydroepiandrosterone (DHEA) to establish an in vivo model of PCOS. We found that enhanced activation of NLRP3 inflammasome was accompanied by downregulation of miR-1224-5p in ovarian tissue of PCOS mice. The effect of miR-1224-5p was further explored in TNF-α-treated human granulosa-like tumor (KGN) cells. Upregulation of miR-1224-5p suppressed TNF-α-induced secretion of DHEA and testosterone. MiR-1224-5p attenuated TNF-α-induced inflammation by inhibiting NLRP3 inflammasome activation, IL-1β synthesis, and nuclear factor kappa B (NF-κB) p65 nuclear translocation. Notably, miR-1224-5p decreased the expression of Forkhead box O 1 (FOXO1) and its downstream gene thioredoxin interaction protein (TXNIP). Luciferase reporter assay confirmed FOXO1 as a target of miR-1224-5p. Upregulation of FOXO1 abolished miR-1224-5p-induced activation of NLRP3 inflammasome, demonstrating that miR-1224-5p might inhibit NLRP3 inflammasome activation through regulating FOXO1. This study provided novel insights into the pathogenesis of PCOS and suggested that miR-1224-5p might be a promising target for treating PCOS.

The effect of mitochondria-targeted antioxidant MitoQ10 on redox signaling pathway components in PCOS mouse model

PURPOSE

Considerable evidence suggests that mitochondrial dysfunction and oxidative stress contribute to the pathogenesis of Polycystic ovary syndrome (PCOS). We aimed to evaluate the effectiveness of mitochondria-targeted antioxidant, MitoQ10, on the redox signaling pathway's component in PCOS.

METHOD

We assessed TXNIP, TRX, and ASK1 expression in granulosa cells (GCs) of the DHEA-induced PCOS mouse model. Female BALB/c mice in five groups of Control, DHEA, and DHEA + MitoQ10 in three doses of 250, 500, and 750 μmol/L MitoQ10 were treated for 21 days.

RESULTS

Histological investigation showed a probable improvement in folliculogenesis; besides, ASK1 and TXNIP expression were significantly increased in GCs of the PCOS mouse F4Fmodel as compared to the control groups and decreased steadily in groups treated by MitoQ10. However, TRX expression showed a drop that was restored by MitoQ10 meaningfully (P ≤ 0.05).

CONCLUSION

The work presented herein suggests mitochondria-targeted antioxidant, MitoQ10, have modulating effects on folliculogenesis in the ovary and also on the redox signaling pathway in GCs of PCOS mouse model which may have potential to attenuate oxidative stress and its relative damages.

Direct impact of gonadotropins on glucose uptake and storage in preovulatory granulosa cells: Implications in the pathogenesis of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is often associated with higher levels of LH, and arrested ovarian follicular growth. The direct impact of high LH on FSH mediated metabolic responses in PCOS patients is not clearly understood.

METHOD

In order to investigate the impact of FSH and LH on glucose metabolism in preovulatory granulosa cells (GCs), we used [U¹⁴C]-2 deoxyglucose, D-[U¹⁴C]-glucose or 2-NBD glucose to analyse glucose uptake and its incorporation into glycogen. To reproduce the high androgenic potential in PCOS patients, we administered hCG both in vitro and in vivo. The role of IRS-2/PI3K/Akt2 pathway was studied after knockdown with specific siRNA. Immunoprecipitation and specific assays were used for the assessment of IRS-2, glycogen synthase and protein phosphatase 1. Furthermore, we examined the in vivo effects of hCG on FSH mediated glycogen increase in normal and PCOS rat model. HEK293 cells co-expressing FSHR and LHR were used to demonstrate glucose uptake and BRET change by FSH and hCG.

RESULTS

In normal human and rat granulosa cells, FSH is more potent than hCG in stimulating glucose uptake, however glycogen synthesis was significantly upregulated only by FSH through increase in activity of glycogen synthase via IRS-2/PI3K/Akt2 pathway. On the contrary, an impaired FSH-stimulated glucose uptake and glycogen synthesis in granulosa cells of PCOS-patients indicated a selective defect in FSHR activation. Further, in normal human granulosa cells, and in immature rat model, the impact of hCG on FSH responses was such that it inhibited the FSH-mediated glucose uptake as well as glycogen synthesis through inhibition of FSH-stimulated IRS-2 expression. These findings were further validated in HEK293 cells overexpressing Flag-LHR and HA-FSHR, where high hCG inhibited the FSH-stimulated glucose uptake. Notably, an increased BRET change was observed in HEK293 cells expressing FSHR-Rluc8 and LHR-Venus possibly suggesting increased heteromerization of LHR and FSHR in the presence of both hCG and FSH in comparison to FSH or hCG alone.

CONCLUSION

Our findings confirm a selective attenuation of metabolic responses to FSH such as glucose uptake and glycogen synthesis by high activation level of LHR leading to the inhibition of IRS-2 pathway, resulting in depleted glycogen stores and follicular growth arrest in PCOS patients.

The AMPK-mTOR axis requires increased MALAT1 expression for promoting granulosa cell proliferation in endometriosis

Endometriosis is a common reproductive disorder in women, with a global prevalence of 10-15%. Long noncoding RNAs (lncRNAs) are critical to gene transcription, cell cycle modulation and immune response. The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) reportedly mediates autophagy of endometrial stromal cells in endometriosis. The present study aimed to evaluate the role and mechanism of MALAT1 in granulosa cells (GCs) in endometriosis. Consequently, MALAT1 expression was upregulated in GCs obtained from patients with endometriosis and in the steroidogenic human granulosa-like tumor cell line KGN. However, MALAT1 knockdown consequently decreased the proliferation and viability of these cells, as determined by MTT and 5-ethynyl-2'-deoxyuridine staining assays. Both Annexin V-fluorescein isothiocyanate/propidium iodide flow cytometry and western blotting performed to detect proapoptotic factors indicated that MALAT1 depletion might promote KGN cell apoptosis. Furthermore, MALAT1 knockdown increased GC autophagy, as evidenced by microtubule-associated protein 1A/1B-light chain 3 (LC3) cleavage upregulation and p62 degradation. In addition, although 5'-AMP-activated protein kinase (AMPK) mRNA expression and protein levels decreased in GCs obtained from patients with endometriosis and KGN cells, MALAT1 knockdown restored AMPK levels. However, addition of BML-275 (MALAT1 inhibitor) to MALAT1-knockdown KGN cells recovered their viability and proliferative capacity and simultaneously reduced their apoptotic and autophagic capacity. Therefore, MALAT1 may regulate GC proliferation via AMPK-mTOR-mediated cell apoptosis and autophagy.

Long non-coding RNA TUG1 and its molecular mechanisms in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) causes anovulatory infertility in women of reproductive age, but etiopathogenesis of PCOS remains undetermined. Taurine up-regulated 1 (TUG1), an evolutionarily conserved long non-coding RNA, performs various biological functions; however, the role of TUG1 in PCOS remains unclear. Herein, TUG1 expression was assayed in granulosa cells (GCs) of 100 patients with PCOS and 100 control participants. Receiver operating characteristic (ROC) curve analysis was conducted to determine the diagnostic value of TUG1 in PCOS. TUG1 expression was also silenced in KGN cells to explore the role of TUG1 in cellular proliferation, apoptosis, cell-cycle progression, autophagy, and steroidogenesis. We found that TUG1 levels were dramatically increased in the PCOS group compared with those of the control group; this increased expression was related to a rising antral follicle count (R = 0.209, P < 0.001 versus control). The ROC curve indicated a significant separation between PCOS group and the control group (AUC: 0.702; 95% CI: 0.630-0.773; P < 0.001). TUG1 showed a predominantly nuclear localization in human GCs. TUG1 knockdown reduced cellular proliferation, and promoted MAPKs pathway-dependent apoptosis and P21-dependent autophagy, but may not affect cell-cycle progression. TUG1 knockdown increased aromatase expression and oestradiol biosynthesis. Our results indicate that increased TUG1 expression in PCOS GCs may contribute to excessive follicular activation and growth, and may disrupt the selection of dominant follicle. Our study shows that TUG1 can be used as a diagnostic biomarker for PCOS.

miR‑132 is upregulated in polycystic ovarian syndrome and inhibits granulosa cells viability by targeting Foxa1

Polycystic ovary syndrome (PCOS) is one of the most common endocrine metabolic disorders characterized by hyperandrogenism, polycystic ovaries and ovulatory dysfunction. Several studies have suggested that the aberrant expression of microRNAs (miRNAs/miRs) plays an important role in the pathogenesis of PCOS; however, the role and underlying mechanisms of miR-132 in the development of PCOS remain unclear. In the present study, the expression of miR-132 in granulosa cells (GCs) derived from 26 patients with PCOS and 30 healthy controls was detected by reverse transcription-quantitative PCR (RT-qPCR). The apoptosis of GCs was examined using a TUNEL assay. The human ovarian granulosa-like tumor cell line, KGN, was cultured for Cell Counting Kit-8 assays following the overexpression or knockdown of miR-132. TargetScan was applied to identify the potential targets of miR-132, which was further verified by a luciferase assay, RT-qPCR and western blotting. The expression of miR-132 was decreased in GCs from patients with PCOS. Moreover, the GCs of patients with PCOS exhibited significantly increased apoptotic nuclei. Furthermore, the overexpression of miR-132 inhibited the viability of KGN cells. In addition, the results verified that miR-132 directly targeted forkhead box protein A1 (Foxa1), the knockdown of which suppressed KGN cell viability. On the whole, the findings of the present study demonstrated that miR-132 inhibited cell viability and induced apoptosis by directly interacting with Foxa1. Thus, miR-132 may be a potential target for the treatment of patients with PCOS.

Identification of Crucial lncRNAs, miRNAs, mRNAs, and Potential Therapeutic Compounds for Polycystic Ovary Syndrome by Bioinformatics Analysis

BACKGROUND

This study was aimed at mining crucial long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs) for the development of polycystic ovary syndrome (PCOS) based on the coexpression and the competitive endogenous RNA (ceRNA) theories and investigating the underlying therapeutic drugs that may function by reversing the expression of lncRNAs, miRNAs, and mRNAs.

METHODS

RNA (GSE106724, GSE114419, GSE137684, and GSE138518) or miRNA (GSE84376 and GSE138572) expression profile datasets of PCOS patients were downloaded from the Gene Expression Omnibus database. The weighted gene coexpression network analysis (WGCNA) using four RNA datasets was conducted to construct the lncRNA-mRNA coexpression networks, while the common differentially expressed miRNAs in two miRNA datasets and module RNAs were used to establish the ceRNA network. A protein-protein interaction (PPI) network was created to explore the potential interactions between genes. Gene Ontology and KEGG pathway enrichment analyses were performed to explore the functions of genes in networks. Connectivity Map (CMap) and Comparative Toxicogenomics Database (CTD) analyses were performed to identify potential therapeutic agents for PCOS.

RESULTS

Three modules (black, magenta, and yellow) were identified to be PCOS-related after WGCNA analysis, in which KLF3-AS1-PLCG2, MAPKAPK5-AS1-MAP3K14, and WWC2-AS2-TXNIP were important coexpression relationship pairs. WWC2-AS2-hsa-miR-382-PLCG2 was a crucial ceRNA loop in the ceRNA network. The PPI network showed that MAP3K14 and TXNIP could interact with hub genes PLK1 (degree = 21) and TLR1 (degree = 18), respectively. These genes were enriched into mitosis (PLK1), immune response (PLCG2 and TLR1), and cell cycle (TXNIP and PLK1) biological processes. Ten small molecule drugs (especially quercetin) were considered to be therapeutical for PCOS.

CONCLUSION

Our study may provide a novel insight into the mechanisms and therapy for PCOS.

Persistent effects on bovine granulosa cell transcriptome after resolution of uterine disease

Metritis is associated with reduced fertility in dairy cows, but the mechanisms are unclear because the disease resolves several weeks before insemination. One hypothesis is that metritis causes persistent changes in granulosa cells during follicle development, which might be evident in the transcriptome of granulosa cells from dominant follicles weeks after parturition. To test this hypothesis, we collected the follicular fluid and granulosa cells from dominant follicles 63 days post partum from cows previously diagnosed with metritis, at least 6 weeks after resolution of the disease and from cows not diagnosed with metritis (control cows). Bacterial lipopolysaccharide was detected in follicular fluid, and concentrations were associated with follicular fluid IL-8 and glucose concentrations. Transcriptome analysis using RNAseq revealed 177 differentially expressed genes in granulosa cells collected from cows that had metritis compared with control cows. The most upregulated genes were ITLN1, NCF2, CLRN3, FSIP2 and ANKRD17, and the most downregulated genes were ACSM1, NR4A2, GHITM, CBARP and NR1I3. Pathway analysis indicated that the differentially expressed genes were involved with immune function, cell-cell communication, cell cycle and cellular metabolism. Predicted upstream regulators of the differentially expressed genes included NFκB, IL-21 and lipopolysaccharide, which are associated with infection and immunity. Our data provide evidence for a persistent effect of metritis on the transcriptome of granulosa cells in ovarian follicles after the resolution of disease.

Down-regulation of long non-coding RNA MALAT1 inhibits granulosa cell proliferation in endometriosis by up-regulating P21 via activation of the ERK/MAPK pathway

STUDY QUESTION

Is there a specific mechanism underlying the association between lung adenocarcinoma transcript 1 (MALAT1) and endometriosis-related infertility?

SUMMARY ANSWER

The down-regulation of MALAT1 in endometriosis granulosa cells (GCs) may have an adverse effect on the growth and development of oocytes by inhibiting GC proliferation, due to cell cycle-dependent mechanisms that enhance P21 expression through activation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway.

WHAT IS KNOWN ALREADY

The association between endometriosis and infertility is well supported throughout the literature, and endometriosis per se and its surgical treatment have an adverse effect on the ovarian reserve and on oocyte development. MALAT1, one of the most extensively expressed and evolutionarily conserved transcripts, has been implicated to play a role in human development and many diseases. However, little is known about the role of MALAT1 long non-coding RNA (lncRNA) in endometriosis and its associated infertility.

STUDY DESIGN, SIZE, DURATION

We measured MALAT1 lncRNA expression levels in GCs from 52 endometriosis patients and 52 controls. Also, MALAT1 was knocked down in a human GC tumor-derived cell line, KGN, to investigate the role of MALAT1 and its molecular mechanism in cell proliferation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

GCs were collected from women with or without endometriosis undergoing IVF or ICSI treatment. All endometriosis patients were diagnosed by laparoscopy or laparotomy, and control patients were limited to male factor or tubal disease and had a normal ovarian reserve. Quantitative real-time PCR (qRT-PCR) was used to measure the differential expression levels of MALAT1 lncRNA between endometriosis patients and controls. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic values of MALAT1 in endometriosis. In the KGN cell line, MALAT1 was knocked down with locked nucleic acid GapmeRs. Cell counting kit-8 assays, ethynyl-2-deoxyuridine assays and flow cytometry were used to study the role of MALAT1 in cell proliferation and cell-cycle progression, and western blotting was performed to detect the potential underlying mechanism.

MAIN RESULTS AND THE ROLE OF CHANCE

We first found that MALAT1 lncRNA was significantly down-regulated in endometriosis GCs and was associated with the antral follicle count (R = 0.376, P < 0.001 versus control). In addition, MALAT1 lncRNA levels were significantly lower in the GCs of infertile women with advanced stages of endometriosis (P = 0.01 versus control). The ROC curves illustrated strong separation between all the endometriosis patients and the control group (AUC: 0.705; 95% CI: 0.606-0.804; P < 0.001), Stage I-II and control group (AUC: 0.651; 95% CI: 0.536-0.767; P = 0.016), and Stage III-IV and control group (AUC: 0.827; 95% CI: 0.718-0.936; P < 0.001). MALAT1 lncRNA was primarily localized in the nuclei of GCs. We found a negative correlation between MALAT1 lncRNA and P21 mRNA in the GCs from patients (R = -0.628; P < 0.001). MALAT1 knockdown in KGN cells inhibited cell proliferation and cell-cycle progression. In addition, MALAT1 knockdown induced an increase in both the mRNA and protein levels of P21, and of P53, phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated c-Jun N-terminal protein kinase (p-JNK) protein levels, as well as causing a decrease in cyclin dependent kinase 2 (CDK2), cyclin D1 and p-P38 MAPK protein levels. Furthermore, inhibition of the ERK/MAPK pathway with U0126, the up-regulation of p-ERK1/2, P21 and P53, and the down-regulation of CDK2 and cyclin D1 by the knockdown of MALAT1 were all attenuated by MALAT1 knockdown. Therefore, MALAT1 may regulate GC proliferation through P21/P53-dependent control of the cell cycle, and the ERK/MAPK pathway participates in this process.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The hormonal treatment used in IVF and surgical removal of endometriotic lesions may have altered MALAT1 expression in GCs. The ovarian granulosa-like tumor cell line, KGN, was used for further functional and mechanistic studies due to the difficulties in obtaining human GCs in sizable amounts and maintaining primary cultures.

WIDER IMPLICATIONS OF THE FINDINGS

Our finding represents the first example of an lncRNA-based mechanism in endometriosis GCs. Women with endometriosis show altered MALAT1 expression levels in GCs that may impair fertility by regulating the function of GCs. Therefore, analysis of MALAT1 and its molecular mechanisms of action provide new insights into the pathogenesis of endometriosis and its associated infertility.

STUDY FUNDING/COMPETING INTEREST(s)

This work was supported by the National Natural Science Foundation of China (grant number: 81671524) and the National key research and development program of China (grant number: 2017YFC1001100). The authors declare there is no conflict of interest.

Downregulation of Lnc-OC1 attenuates the pathogenesis of polycystic ovary syndrome

Long non-coding RNAs (lncRNAs) play a vital role in the progression of many human diseases. The aim of this study is to explore the relationship between lncRNA-ovarian cancer associated 1 (Lnc-OC1) and PCOS. In this study, we found that Lnc-OC1 was significantly higher in PCOS granulosa cells (GCs) compared to non-PCOS GCs. Lnc-OC1 knockdown inhibited cell viability and promoted cell apoptosis, expression of aromatase mRNA and production of estradiol in KGN cells. In PCOS mice, Lnc-OC1 promoted the serum insulin release, production of angiogenesis-related factors and IκBα phosphorylation, which could be partially restored by Lnc-OC1 shRNA. These results suggest that Lnc-OC1 plays an important part in the pathogenesis of PCOS.

Upregulation of microRNA-204 improves insulin resistance of polycystic ovarian syndrome via inhibition of HMGB1 and the inactivation of the TLR4/NF-κB pathway

There is growing evidence of the position of microRNAs (miRs) in polycystic ovarian syndrome (PCOS), thus our objective was to discuss the impact of miR-204 on insulin resistance (IR) in PCOS by targeting highmobility group box protein 1(HMGB1)-mediated toll-like receptor 4(TLR4)/nuclear factor-kappa B (NF-κB) pathway.PCOS-IR patients and PCOS non-insulin resistance (PCOS-NIR) patients were included. The levels of serum sex hormones and related insulin were measured, the expression of miR-204, HMGB1, TLR4 and NF-κB p65 was detected, the diagnostic efficacy of miR-204 in PCOS-IR was analyzed, and the correlation between the expression of miR-204 in PCOS-IR and fasting blood glucose (FPG), fasting insulin (FINS), homeostasis model of assessment for insulin resistance index (HOMA-IR) was analyzed. Both in vitro and in vivo experiments were performed to elucidate the capabilities of miR-204 and HMGB1 in proliferation and apoptosis of PCOS-IR granulosa cells.MiR-204 was lowly expressed as well as HMGB1, TLR4 and NF-κB p65 were highly expressed in PCOS-IR patients. Follicule-stimulating hormone was downregulated, while luteinizing hormone, estrogen, progesterone, FPG, FINS and HOMA-IR were elevated in PCOS-IR. Upregulation of miR-204 and downregulation of HMGB1 could repress TLR4/NF-κB pathway activation, degraded insulin release and testosterone (T) leveland ascended ovarian coefficient, boosted cell proliferation and restrained apoptosis of granulosa cells. Overexpression of HMGB1 reverses the effect of upregulation of miR-204 on IR of PCOS.Our study presents that high expression of miR-204 or inhibition of HMGB1 can improve IR of PCOS via the inactivation of TLR4/NF-κB pathway.

Up-regulated FHL2 inhibits ovulation through interacting with androgen receptor and ERK1/2 in polycystic ovary syndrome

BACKGROUND

The ovulatory dysfunction mechanisms underlying polycystic ovary syndrome (PCOS) are not completely understood. There is no effective therapy for PCOS so far.

METHODS

We measured the expression of four and a half LIM domain 2 (FHL2) and other related-genes in human granulosa cells (hGCs) from patients with and without PCOS. To minimise the heterogeneity of patients with PCOS, we only included PCOS patients meeting all three criteria according to the revised Rotterdam consensus. The in vitro effects of FHL2 on ovulatory genes and the underlying mechanisms were examined in KGN cells. The role of FHL2 in ovulation was investigated in vivo by overexpressing FHL2 in rat ovaries via intrabursal lentivirus injection.

FINDINGS

Increased FHL2 and androgen receptor (AR) expression and decreased CCAAT/enhancer-binding protein β (C/EBPβ) expression were observed in hGCs from patients with PCOS. FHL2 inhibited the expression of ovulation-related genes, including phosphorylated ERK1/2, C/EBPβ, COX2 and HAS2 in KGN cells. It was partially by interacting with AR to act as its co-regulator to inhibit C/EBPβ expression and by binding to ERK1/2 to inhibit its phosphorylation. Moreover, FHL2 abundance in hGCs was positively correlated with the basal serum testosterone concentration of patients with PCOS, and dihydrotestosterone (DHT)-induced FHL2 upregulation was mediated by AR signalling in KGN cells. Additionally, lentiviral-mediated functional FHL2 overexpression in rat ovaries for 1 week contributed to an impaired superovulatory response, displaying decreased numbers of retrieved oocytes and a lower MII oocyte rate. 3-week FHL2 overexpression rat models without superovulation led to acyclicity and polycystic ovary morphology.

INTERPRETATION

Our findings provide novel insights into the mechanisms underlying the pathogenesis of PCOS, suggesting that FHL2 could be a potential treatment target for ovulatory obstacles in PCOS. FUND: National Key Research and Development Program of China, National Natural Science Foundation, National Institutes of Health project and Shanghai Commission of Science and Technology.

Cisplatin treatment of testicular cancer patients introduces long-term changes in the epigenome

BACKGROUND

Cisplatin-based chemotherapy (CBCT) is part of standard treatment of several cancers. In testicular cancer (TC) survivors, an increased risk of developing metabolic syndrome (MetS) is observed. In this epigenome-wide association study, we investigated if CBCT relates to epigenetic changes (DNA methylation) and if epigenetic changes render individuals susceptible for developing MetS later in life. We analyzed methylation profiles, using the MethylationEPIC BeadChip, in samples collected ~ 16 years after treatment from 279 Norwegian TC survivors with known MetS status. Among the CBCT treated (n = 176) and non-treated (n = 103), 61 and 34 developed MetS, respectively. We used two linear regression models to identify if (i) CBCT results in epigenetic changes and (ii) epigenetic changes play a role in development of MetS. Then we investigated if these changes in (i) and (ii) links to genes, functional networks, and pathways related to MetS symptoms.

RESULTS

We identified 35 sites that were differentially methylated when comparing CBCT treated and untreated TC survivors. The PTK6-RAS-MAPk pathway was significantly enriched with these sites and infers a gene network of 13 genes with CACNA1D (involved in insulin release) as a network hub. We found nominal MetS-associations and a functional gene network with ABCG1 and NCF2 as network hubs.

CONCLUSION

Our results suggest that CBCT has long-term effects on the epigenome. We could not directly link the CBCT effects to the risk of developing MetS. Nevertheless, since we identified differential methylation occurring in genes associated with conditions pertaining to MetS, we hypothesize that epigenomic changes may also play a role in the development of MetS in TC survivors. Further studies are needed to validate this hypothesis.

MiR-29a regulates the proliferation, aromatase expression, and estradiol biosynthesis of human granulosa cells in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in reproductive-aged women; however, its etiology remains poorly understood. This study aimed to reveal the role of miR-29a in PCOS. MiR-29a levels were measured in the granulosa cells (GCs) of forty-seven PCOS patients and forty-seven controls. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of miR-29a in non-hyperandrogenism PCOS. MiR-29a was overexpressed in KGN and COV434 cells to examine its roles in proliferation, cell-cycle progression, and steroidogenesis. MiR-29a was significantly down-regulated in PCOS patients, and associated with an increased antral follicle count. The ROC curve showed a major separation between PCOS patients and controls. MiR-29a overexpression in KGN and COV434 cells inhibited cell proliferation, arrested cell-cycle progression, and decreased aromatase expression and estradiol production. These findings suggest that miR-29a is involved in GC proliferation and steroidogenesis, providing insights into PCOS pathogenesis.

Age, body weight and ovarian function affect oocyte size and morphology in non-PCOS patients undergoing intracytoplasmic sperm injection (ICSI)

The size of oocytes was previously reported to be smaller in obese women with polycystic ovary syndrome (PCOS). In the present prospective cohort study, we sought to determine whether oocyte size and morphology are associated with patient characteristics in non-PCOS women. Oocyte and oolemmal diameter were measured, enlarged perivitelline space (PVS) and ooplasmic granulation were assessed in 308 MII oocytes from 77 IVF/ICSI couples. Statistical analysis was undertaken using SAS version 9.4 (SAS institute Inc., USA). Continuous values are presented as mean ± SD and compared using a two-sample t-test or Mann-Whitney U test as appropriate. Categorical parameters are presented as proportions and compared using a Fisher exact test. Logistic and linear regression models were used to control for the effect of age for categorical and continuous variables respectively. P-value < 0.05 was considered statistically significant. Patients presented with a mean age of 40.3±5.0 years, had a BMI of 25.1±6.1 kg/m², median AMH levels of 0.6 ng/ml and produced a median of 4 oocytes. Mean total oocyte diameter was 163.2±7.4 μm (range 145.8–182.1 μm), while oolemmal diameter was 109.4±4.1 μm (range 98.5–122.3 μm). After adjusting for age and ovarian reserve increasing BMI was associated with decreased total oocyte diameter (p<0.05). Total oocyte diameter was also inversely associated with AMH levels (p = 0.03) and oocyte yield (p = 0.04). In contrast to total oocyte diameter, oolemmal diameter was not related to patient characteristics. Younger women and those with large oocyte yields demonstrated fewer oocytes with ooplasmic granulation (p<0.05 and p = 0.01). After adjustments for age, ooplasmic granulation was also less frequently observed in oocytes from women with higher AMH (p = 0.03) and increasing BMI (p<0.01). Fertilization was more likely in oocytes with larger oolemmal diameter (p = 0.008). Embryos from oocytes with larger total and ooplasmic diameters were more likely to be transferred or frozen (p = 0.004 and p = 0.01). In non-PCOS infertile women, BMI and ovarian function relate to total oocyte diameter. These results expand on previously observed associations between oocyte size and BMI in women with PCOS. They indicate the importance of detailed oocyte assessments, which may aid the currently used criteria for embryo selection and help to better understand how oocyte status is associated with later embryo development.

Quercetin protects human granulosa cells against oxidative stress via thioredoxin system

Granulosa Cells (GCs) are sensitive to excessive production of reactive oxygen species (ROS). Quercetin (QUR) is a free radical scavenger which can alleviate oxidative stress through nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/antioxidant response element (ARE) pathway and thioredoxin (Trx) system. We aimed to explore the probable protective role of QUR on cultured human GCs treated with hydrogen peroxide (H₂O₂) as an inducer of oxidative stress. MTT assay was applied for evaluating the cell cytotoxicity of QUR and H₂O₂. The rate of apoptotic cells and intracellular ROS generation were determined by Annexin V-FITC/PI staining and 2'-7'-dichlorodihydrofluorescein diacetate fluorescent probes (DCFH-DA), respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blot analysis were used to evaluate the gene and protein expression of Nrf2 and kelch-like ech-associated protein 1 (Keap1)1. The Nrf2 and Trx activities were measured by Enzyme-linked Immunosorbent Assay (ELISA). The results indicated that QUR pretreatment can decrease ROS production and apoptosis induced by H₂O₂. In addition, QUR increased Nrf2 gene and protein expression, as well as its nuclear translocation. Moreover, in QUR-treated group, a lower level of Keap1 protein was observed, which was not reported as significant. The results also indicated a significant correlation between the expression of Nrf2 and Keap1 in QUR-treated group. Further, QUR protected GCs from oxidative stress by increasing Trx gene expression and activity. This study suggests that QUR as a supplementary factor may protect GCs from oxidative stress in diseases related to this condition.