Circulating microRNAs in patients with polycystic ovary syndrome

Extracellular fluid miRNAs in PCOS

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition that impacts both reproductive and metabolic functioning. Despite thorough research, the exact causes of PCOS remain unclear. Recent studies indicate that microRNAs (miRNAs), which are small non-coding RNAs that regulate gene expression, could be crucial for comprehending PCOS. This review article investigates the variations in extracellular fluids miRNAs expression in individuals diagnosed with PCOS and assesses their viability as diagnostic biomarkers, and determines their involvement in the mechanisms underlying the disease. The related reports show that miRNA expression profiles demonstrate notable differences between PCOS patients and healthy subjects. Several miRNAs exhibit dysregulation in essential biological processes such as follicular development, steroidogenesis, insulin signaling, and metabolic pathways. These results imply that miRNAs could lead to hormonal imbalances and metabolic problems linked to PCOS. The variations in miRNA expression noted in patients with PCOS underscore their possible role as biomarkers for the early detection and characterization of the condition. Continued investigation into miRNA-based diagnostic and therapeutic strategies may enhance our comprehension of PCOS. and facilitate the advancement of more precise therapeutic alternatives.

Circulating microRNAs in Body Fluid: "Fingerprint" RNA Snippets Deeply Impact Reproductive Biology

Circulating miRNAs (C-miRNAs) occuring in a cell-free form within body fluids and other extracellular environments have garnered attention in recent times. They offer deeper insight into various physiological and pathological processes which include reproductive health. This review delves into their diagnostic potential across a spectrum of reproductive disorders, including conditions affecting ovarian function, male infertility and post pregnancy issues. Through analysis of C-miRNA profiles in bodily fluids, researchers uncover crucial markers indicative of reproductive challenges. Dysregulated C-miRNAs emerge as important players in the progression of several reproductive disorders which is the main focus of this review. Advancements in technology, facilitate precise detection and quantification of C-miRNAs, paving the way for innovative diagnostic approaches. Challenges in studying C-miRNAs, such as their low abundance and variability in expression levels, underscore the need for standardized protocols and rigorous validation methods. Despite these challenges, ongoing research endeavors aim to unravel the complex regulatory roles of C-miRNAs in reproductive biology, with potential implications for clinical practice and therapeutic interventions.

Decreased miR-128-3p in serum exosomes from polycystic ovary syndrome induces ferroptosis in granulosa cells via the p38/JNK/SLC7A11 axis through targeting CSF1

Increasing evidence suggests that non-coding small RNAs (miRNAs) carried by exosomes (EXOs) play important roles in the development and treatment of polycystic ovary syndrome (PCOS). In this study, we demonstrate that PCOS mouse serum-derived EXOs promote granulosa cells (GCs) ferroptosis, and induce the occurrence of a PCOS-like phenotype in vivo. Notably, EXO miRNA sequencing combined with in vitro gain- and loss-of-function assays revealed that miR-128-3p, which is absent in the serum-derived EXOs of mice with PCOS, regulates lipid peroxidation and GC sensitivity to ferroptosis inducers. Mechanistically, overexpression of CSF1, a direct target of miR-128-3p, reversed the anti-ferroptotic effect of miR-128-3p. Conversely, ferroptosis induction was mitigated in CSF1-downregulated GCs. Furthermore, we demonstrated that miR-128-3p inhibition activates the p38/JNK pathway via CSF1, leading to NRF2-mediated down-regulation of SLC7A11 transcription, which triggers GC iron overload. Moreover, intrathecal miR-128-3p AgomiR injection into mouse ovaries ameliorated PCOS-like characteristics and restored fertility in letrozole-induced mice. The study reveals the pathological mechanisms of PCOS based on circulating EXOs and provides the first evidence of the roles of miR-128-3p and CSF1 in ovarian GCs. This discovery is expected to provide promising therapeutic targets for the treatment of PCOS.

miR-761-hepcidin/Gpx4 pathway contribute to unexplained liver dysfunction in polycystic ovary syndrome by regulating liver iron overload and ferroptosis

Aims: To investigate the underling mechanisms of liver dysfunction in patients with polycystic ovary syndrome (PCOS).Materials and methods: PCOS patients were enrolled according to the Amsterdam criteria while PCOS animal model was established by dihydrotestosterone (DHEA) sustained release tablet implantation on its neck. Further liver damage and iron overload were detected by HE and Prussian blue staining. The liver related enzymes, mRNA and protein levels of hepcidin and GPX4 were tested by ELISA, qRT-PCR and Western blot. RNA interference and miR-761 transfection were routinely performed while the regulation of miR-761 on hepcidin and GPX4 was confirmed by luciferase reporter gene analysis.Results: We found that a part of PCOS patients and animal model had unexplained liver damage, which is independent of nonalcoholic fatty liver disease (NAFLD) and accompanied by increased ferrum (Fe) deposition. Besides, the expression of hepcidin and GPX4 that is important effector proteins for ferroptosis was down regulated in liver, showing the importance of iron metabolism in this unexplained liver damage. Based on the miR-761-hepcidin/GPX4 axis, we systematically studied the effects of miR-761 on ferroptosis and Fe deposition, which further influence the phenotype and liver function of PCOS model. From both in vivo and in vitro levels, changes in PCOS disease phenotype and ferroptosis were observed through hierarchical antagonism or overexpression of miR-761, hepcidin and GPX4.Conclusions: our results provide a novel explanation for unexplained liver damage in PCOS and a potential therapeutic target.

MicroRNA-16 represses granulosa cell proliferation in polycystic ovarian syndrome through inhibition of the PI3K/Akt pathway by downregulation of Apelin13

This study aimed to uncover the specific role of micro RNA-16 (miR-16) in granulosa cell function in polycystic ovarian syndrome (PCOS). After sample collection, the expression levels of miR-16 and Apelin13 in the granulosa cells of PCOS patients and controls were determined. Subsequently, miR-16 mimic, miR-16 inhibitor, pcDNA3.1-Apelin13, sh-Apelin13, and their corresponding negative controls were transfected into granulosa cell lines (KGN and SVOG) to monitor alterations in miR-16 expression, Apelin13, and PI3K/Akt signalling pathway-related proteins (p-Akt and Akt). MTT assay was used to detect cell viability, clone formation assay to detect cell proliferation, and flow cytometry to detect cell apoptosis rate. In addition, a luciferase assay was performed to test the targeting relationship between miR-16 and Apelin13. After miR-16 overexpression or Apelin13 knockdown was achieved in granulosa cells, granulosa cell proliferation was suppressed and cell apoptosis was enhanced. Additionally, Apelin13 is a potential target of miR-16. Functionally, overexpression of Apelin13 could partly reverse the effect of miR-16 overexpression on granulosa cell proliferation and apoptosis. Moreover, inhibits granulosa cell proliferation and enhances blocking the PI3K/Akt pathway by suppressing Apelin13. Our study revealed miR-16 regulates Apelin13 to mediate the PI3K/Akt signalling pathway and, thereby mediates PCOS progression.

HDAC1 participates in polycystic ovary syndrome through histone modification to regulate H19/miR-29a-3p/NLRP3-mediated granulosa cell pyroptosis

Histone deacetylase 1 (HDAC1) is known to participate in the molecular etiology of polycystic ovary syndrome (PCOS). However, its role in granulosa cell (GC) pyroptosis remains unclear. This study sought to investigate the mechanism of HDAC1 in PCOS-induced GC pyroptosis through histone modification. Clinical serum samples and the general data of study subjects were collected. PCOS mouse models were established using dehydroepiandrosterone and cell models were established in HGL5 cells using dihydrotestosterone. Expressions of HDAC1, H19, miR-29a-3p, and NLR family pyrin domain containing 3 (NLRP3) and pyroptosis-related proteins and levels of hormones and inflammatory cytokines were determined. Ovarian damage was observed by hematoxylin-eosin staining. Functional rescue experiments were conducted to verify the role of H19/miR-29a-3p/NLRP3 in GC pyroptosis in PCOS. HDAC1 and miR-29a-3p were downregulated whereas H19 and NLRP3 were upregulated in PCOS. HDAC1 upregulation attenuated ovarian damage and hormone disorders in PCOS mice and suppressed pyroptosis in ovarian tissues and HGL5 cells. HDAC1 inhibited H3K9ac on the H19 promoter and H19 competitively bound to miR-29a-3p to improve NLRP3 expression. Overexpressed H19 or NLRP3 or inhibited miR-29a-3p reversed the inhibition of GC pyroptosis by HDAC1 upregulation. Overall, HDAC1 suppressed GC pyroptosis in PCOS through deacetylation to regulate the H19/miR-29a-3p/NLRP3 axis.

Transgenerational transmission of reproductive and metabolic dysfunction in the male progeny of polycystic ovary syndrome

The transgenerational maternal effects of polycystic ovary syndrome (PCOS) in female progeny are being revealed. As there is evidence that a male equivalent of PCOS may exists, we ask whether sons born to mothers with PCOS (PCOS-sons) transmit reproductive and metabolic phenotypes to their male progeny. Here, in a register-based cohort and a clinical case-control study, we find that PCOS-sons are more often obese and dyslipidemic. Our prenatal androgenized PCOS-like mouse model with or without diet-induced obesity confirmed that reproductive and metabolic dysfunctions in first-generation (F₁) male offspring are passed down to F₃. Sequencing of F₁-F₃ sperm reveals distinct differentially expressed (DE) small non-coding RNAs (sncRNAs) across generations in each lineage. Notably, common targets between transgenerational DEsncRNAs in mouse sperm and in PCOS-sons serum indicate similar effects of maternal hyperandrogenism, strengthening the translational relevance and highlighting a previously underappreciated risk of transmission of reproductive and metabolic dysfunction via the male germline.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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.

Identifying pleiotropic variants and candidate genes for fertility and reproduction traits in Holstein cattle via association studies based on imputed whole-genome sequence genotypes

Background

Genetic progress for fertility and reproduction traits in dairy cattle has been limited due to the low heritability of most indicator traits. Moreover, most of the quantitative trait loci (QTL) and candidate genes associated with these traits remain unknown. In this study, we used 5.6 million imputed DNA sequence variants (single nucleotide polymorphisms, SNPs) for genome-wide association studies (GWAS) of 18 fertility and reproduction traits in Holstein cattle. Aiming to identify pleiotropic variants and increase detection power, multiple-trait analyses were performed using a method to efficiently combine the estimated SNP effects of single-trait GWAS based on a chi-square statistic.

Results

There were 87, 72, and 84 significant SNPs identified for heifer, cow, and sire traits, respectively, which showed a wide and distinct distribution across the genome, suggesting that they have relatively distinct polygenic nature. The biological functions of immune response and fatty acid metabolism were significantly enriched for the 184 and 124 positional candidate genes identified for heifer and cow traits, respectively. No known biological function was significantly enriched for the 147 positional candidate genes found for sire traits. The most important chromosomes that had three or more significant QTL identified are BTA22 and BTA23 for heifer traits, BTA8 and BTA17 for cow traits, and BTA4, BTA7, BTA17, BTA22, BTA25, and BTA28 for sire traits. Several novel and biologically important positional candidate genes were strongly suggested for heifer (SOD2, WTAP, DLEC1, PFKFB4, TRIM27, HECW1, DNAH17, and ADAM3A), cow (ANXA1, PCSK5, SPESP1, and JMJD1C), and sire (ELMO1, CFAP70, SOX30, DGCR8, SEPTIN14, PAPOLB, JMJD1C, and NELL2) traits.

Conclusions

These findings contribute to better understand the underlying biological mechanisms of fertility and reproduction traits measured in heifers, cows, and sires, which may contribute to improve genomic evaluation for these traits in dairy cattle.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08555-z.

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.

miR-124-3p Combined with ANGPTL2 Has High Diagnostic Values for Obese and Nonobese Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a hormonal disorder that affects 5-20% of women of reproductive age. Interestingly, serum miR-124-3p and ANGPTL2 are differentially expressed in PCOS patients. Accordingly, this study set out to explore the clinical roles of serum miR-124-3p/ANGPTL2 in PCOS. Firstly, miR-124-3p/ANGPTL2 expression patterns were detected in the serum of 102 PCOS patients and 100 healthy subjects. miR-124-3p or/and ANGPTL2 diagnostic efficacy on PCOS was further analyzed, in addition to the measurement of lipid metabolism, glucose metabolism, sex hormone indexes, and inflammation levels. Correlations between serum miR-124-3p/ANGPTL2 expressions and age, BMI, Ferriman-Gallwey score, lipid metabolism, glucose metabolism, sex hormone indexes, TNF-α, and IL-6 in PCOS patients were determined. The expression correlation and binding relationship of ANGPTL2 and miR-124-3p were identified. In addition, miR-124-3p was downregulated and ANGPTL2 was upregulated in the serum of obese and nonobese PCOS patients. miR-124-3p expression was found to be negatively correlated with Ferriman-Gallwey score and serum total testosterone (T), and negatively related to prolactin (PRL). ANGPTL2 expression was positively correlated with FNS and inversely linked with PRL. TNF-α and IL-6 were negatively correlated with miR-124-3p, but positively correlated with ANGPTL2. Furthermore, there was a negative correlation and a targeting relationship between ANGPTL2 and miR-124-3p expression in the serum of obese and nonobese PCOS patients. Collectively, our findings indicated that miR-124-3p might target ANGPTL2 expression in obese and nonobese PCOS patients, and further underscored the diagnostic value of their combination.

Chinese herbal medicine for subfertile women with polycystic ovarian syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is characterised by both metabolic and reproductive disorders, and affects 5% to 15% of women of reproductive age. Different western medicines have been proposed for PCOS-related subfertility, such as oral contraceptives, insulin sensitisers and laparoscopic ovarian drilling (LOD). Chinese herbal medicines (CHM) have also been used for subfertility caused by PCOS for decades, and are expected to become an alternative treatment for subfertile women with PCOS.

OBJECTIVES

To assess the efficacy and safety of Chinese herbal medicine (CHM) for subfertile women with polycystic ovarian syndrome (PCOS).

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase and six other databases, from inception to 2 June 2020. In addition, we searched three trials registries, the reference lists of included trials and contacted experts in the field to locate trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing CHM versus placebo, no treatment or conventional (western) therapies for the treatment of subfertile women with PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials for inclusion, assessed the risk of bias in included studies and extracted data. We contacted primary study authors for additional information. We conducted meta-analyses. We used the odds ratios (ORs) to report dichotomous data, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods.

MAIN RESULTS

We included eight RCTs with 609 participants. The comparisons in the included trials were as follows: CHM versus clomiphene, CHM plus clomiphene versus clomiphene (with or without ethinyloestradiol cyproterone acetate (EE/CPA)), CHM plus follicle aspiration plus ovulation induction versus follicle aspiration plus ovulation induction alone, and CHM plus laparoscopic ovarian drilling (LOD) versus LOD alone. The overall certainty of the evidence for most comparisons was very low. None of the included studies reported the primary outcome, live birth rate. Most studies reported the secondary outcomes, and only one study reported data on adverse events. In trials that compared CHM to clomiphene (with or without LOD in both study arms), we are uncertain of the effect of CHM on pregnancy rates (odds ratio (OR) 1.41, 95% confidence interval (CI) 0.63 to 3.19; I2 = 28%; 3 studies, 140 participants; very low certainty evidence). Results suggest that if the chance of pregnancy following clomiphene is assumed to be 21.5%, the chance following CHM would vary between 14.7% and 46.7%. No study reported data on adverse events. When CHM plus clomiphene was compared to clomiphene (with or without EE/CPA), there was low certainty evidence of a higher pregnancy rate in the CHM plus clomiphene group (OR 3.06, 95% CI 2.05 to 4.55; I2 = 10%; 6 studies, 470 participants; low certainty evidence). Results suggest that if the chance of pregnancy following clomiphene is assumed to be 31.5%, the chance following CHM plus clomiphene would vary between 48.5% and 67.7%. No data were reported on adverse events. In trials that compared CHM plus follicle aspiration and ovulation induction to follicle aspiration and ovulation induction alone, we are uncertain of the effect of CHM on pregnancy rates (OR 1.62, 95% CI 0.46 to 5.68; 1 study, 44 women; very low certainty evidence). Results suggest that if the chance of pregnancy following follicle aspiration and ovulation induction is assumed to be 29.2%, the chance following CHM with follicle aspiration and ovulation induction would vary between 15.9% and 70%. Reported adverse events included severe luteinised unruptured follicle syndrome (LUFS) (Peto OR 0.60, 95% CI 0.06 to 6.14; 1 study, 44 women; very low certainty evidence), ovarian hyperstimulation syndrome (OHSS) (Peto OR 0.16, 95% CI 0.00 to 8.19; 1 study, 44 women; very low certainty evidence) or multiple pregnancy (Peto OR 0.60, 95% CI 0.06 to 6.14; 1 study, 44 women; very low certainty evidence). These results suggest that if the chances of LUFS, OHSS, and multiple pregnancy following follicle aspiration and ovulation induction are assumed to be 8.3%, 4.2%, and 8.3% respectively, the chances following CHM with follicle aspiration and ovulation induction would be 0.5% to 35.8%, 0% to 26.3% and 0.5% to 35.8% respectively.  In trials that compared CHM plus LOD to LOD alone, we are uncertain if CHM improves pregnancy rates (OR 3.50, 95% CI 0.72 to 17.09; 1 study, 30 women; very low certainty evidence). Results suggest that if the chance of pregnancy following LOD is assumed to be 40%, the chance following CHM with LOD would vary between 32.4% and 91.9%. No data were reported on adverse events. We are uncertain of the results in the comparison groups for all outcomes. The certainty of the evidence for all other comparisons and outcomes was very low. The main limitations in the evidence were failure to report live birth or adverse events, failure to describe study methods in adequate detail and imprecision due to very low event rates and wide CIs.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support the use of CHM for subfertile women with PCOS. No data are available on live birth. We are uncertain of the effect of CHM on pregnancy rates for there is no consistent evidence to indicate that CHM influences fertility outcomes. However, we find that the addition of CHM to clomiphene may improve pregnancy rates, but there is very limited, low certainty evidence for this outcome. Furthermore, there is insufficient evidence on adverse effects to indicate whether CHM is safe. In the future, well-designed, carefully conducted RCTs are needed, with a particular focus on the live birth rate and other safety indexes.

The role of miRNAs in polycystic ovary syndrome with insulin resistance

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Epigenetic Marks in Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS) is a common endocrine and metabolic disorder that affects women in their reproductive age. Recent studies have shown that genes have an important role in the etiology of PCOS. However, the precise way in which these genes are transcriptionally and post-transcriptionally regulated is poorly understood. The aim of the present review is to provide updated information on miRNAs and DNA methylation as epigenetic marks of PCOS. The data presented here allow concluding that both microRNAs and DNA methylation can be considered as possible useful biomarkers when choosing the treatment for a specific PCOS phenotype and thus represent two important tools for the diagnosis and treatment of PCOS patients.

MicroRNA-Mediated Gene Regulatory Mechanisms in Mammalian Female Reproductive Health

Mammalian reproductive health affects the entire reproductive cycle starting with the ovarian function through implantation and fetal growth. Various environmental and physiological factors contribute to disturbed reproductive health status leading to infertility problems in mammalian species. In the last couple of decades a significant number of studies have been conducted to investigate the transcriptome of reproductive tissues and organs in relation to the various reproductive health issues including endometritis, polycystic ovarian syndrome (PCOS), intrauterine growth restriction (IUGR), preeclampsia, and various age-associated reproductive disorders. Among others, the post-transcriptional regulation of genes by small noncoding miRNAs contributes to the observed transcriptome dysregulation associated with reproductive pathophysiological conditions. MicroRNAs as a class of non-coding RNAs are also known to be involved in various pathophysiological conditions either in cellular cytoplasm or they can be released to the extracellular fluid via membrane-bounded extracellular vesicles and proteins. The present review summarizes the cellular and extracellular miRNAs and their association with the etiology of major reproductive pathologies including PCOS, endometritis, IUGR and age-associated disorders in various mammalian species.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

miR-4463 regulates aromatase expression and activity for 17β-estradiol synthesis in response to follicle-stimulating hormone

Objective

The aim of this study was to investigate microRNAs (miRNAs) related to follicle-stimulating hormone (FSH) responsiveness using miRNA microarrays and to identify their target genes to determine the molecular regulatory pathways involved in FSH signaling in KGN cells.

Methods

To change the cellular responsiveness to FSH, KGN cells were treated with FSH receptor (FSHR)-specific small interfering RNA (siRNA) followed by FSH. miRNA expression profiles were determined through miRNA microarray analysis. Potential target genes of selected miRNAs were predicted using bioinformatics tools, and their regulatory function was confirmed in KGN cells.

Results

We found that six miRNAs (miR-1261, miR-130a-3p, miR-329-3p, miR-185-5p, miR-144-5p and miR-4463) were differentially expressed after FSHR siRNA treatment in KGN cells. Through a bioinformatics analysis, we showed that these miRNAs were predicted to regulate a large number of genes, which we narrowed down to cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and estrogen receptor alpha (ESR1) as the main targets for miR-4463. Functional analysis revealed that miR-4463 is a regulatory factor for aromatase expression and function in KGN cells.

Conclusion

In this study, we identified differentially expressed miRNAs related to FSH responsiveness. In particular, upregulation of miR-4463 expression by FSHR deficiency in human granulosa cells impaired 17β-estradiol synthesis by targeting CYP19A1 and ESR1. Therefore, our data might provide novel candidates for molecular biomarkers for use in research into poor responders.

Circulating and Adipose Tissue miRNAs in Women With Polycystic Ovary Syndrome and Responses to High-Intensity Interval Training

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally. In women with polycystic ovary syndrome (PCOS), several miRNAs are differentially expressed compared to women without PCOS, suggesting a role for miRNAs in PCOS pathophysiology. Exercise training modulates miRNA abundance and is primary lifestyle intervention for women with PCOS. Accordingly, we measured the expression of eight circulating miRNAs selected a priori along with miRNA expression from gluteal and abdominal adipose tissue (AT) in 12 women with PCOS and 12 women matched for age and body mass index without PCOS. We also determined the miRNA expression “signatures” before and after high-intensity interval training (HIT) in 42 women with PCOS randomized to either: (1) low-volume HIT (LV-HIT, 10 × 1 min work bouts at maximal, sustainable intensity, n = 13); (2) high-volume HIT (HV-HIT, 4 × 4 min work bouts reaching 90–95% of maximal heart rate, n = 14); or (3) non-exercise control (Non-Ex, n = 15). Both HIT groups trained three times/week for 16 weeks. miRNAs were extracted from plasma, gluteal and abdominal AT, and quantified via a customized plate array containing eight miRNAs associated with PCOS and/or exercise training responses. Basal expression of circulating miRNA-27b (c-miR-27b), implicated in fatty acid metabolism, adipocyte differentiation and inflammation, was 1.8-fold higher in women with compared to without PCOS (P = 0.006) despite no difference in gluteal or abdominal AT miR-27b expression. Only the HV-HIT protocol increased peak oxygen uptake (VO₂peak L/min; 9%, P = 0.008). There were no changes in body composition. In LV-HIT, but not HV-HIT, the expression of c-miR-27b decreased (0.5-fold, P = 0.007). None of the remaining seven circulating miRNAs changed in LV-HIT, nor was the expression of gluteal or abdominal AT miRNAs altered. Despite increased cardiorespiratory fitness, HV-HIT did not alter the expression of any circulating, gluteal or abdominal AT miRNAs. We conclude that women with PCOS have a higher basal expression of c-miR-27b compared to women without PCOS and that 16 weeks of LV-HIT reduces the expression of this miRNA in women with PCOS. Intense exercise training had little effect on the abundance of the selected miRNAs within subcutaneous AT depots in women with PCOS.

The expression of small RNAs in exosomes of follicular fluid altered in human polycystic ovarian syndrome

Polycystic ovary syndrome (PCOS) can cause reproductive disorders that may affect oocyte quality from punctured follicles in human follicular fluid (HFF). The non-coding RNA family includes micro RNA (miRNA), piwi-interacting RNA (piRNA) and transfer RNA (tRNA); these non-coding RNA transcripts play diverse functions and are implicated in a variety of diseases and health conditions, including infertility. In this study, to explore the role of HFF exosomes in PCOS, we extracted and sequenced RNA from HFF exosomes of PCOS patients and compared the analysis results with those of non-PCOS control group. The HFF exosomes were successfully isolated and characterized in a variety of ways. The sequencing results of the HFF exosomal RNA showed that about 6.6% of valid reads in the PCOS group and 8.6% in the non-PCOS group were successfully mapped to the human RNA database. Using a hierarchical clustering method, we found there were ten small RNA sequences whose expression was significantly different between the PCOS and non-PCOS groups. We chose six of them to predict target genes of interest for further GO analysis, and pathway analysis showed that the target genes are mainly involved in biosynthesis of amino acids, glycine, serine and glycosaminoglycan, as well as threonine metabolism. Therefore, the small RNA sequences contained in HFF EXs may play a key role in the mechanism that drives PCOS pathogenesis, and thereby can act as molecular biomarkers for PCOS diagnosis in the future.

MiR-4485-3p expression reduced in spermatozoa of men with idiopathic asthenozoospermia

Asthenozoospermia (AZS), which characterised by reduced forward sperm motility, is a common cause of male infertility. Recently, mitochondrial dysfunction reported in AZS men came to attention for finding the molecular aetiology of AZS. Mitochondria-related microRNAs (miRNAs) are the most important regulators of mitochondrial function through post-transcriptionally modulation of gene expression. Therefore, this study aims to evaluate the expression of four recently reported mitochondrial-related miRNAs (miR-4485-3p/4484/4461 and 4463) in the sperm sample of asthenozoospermic men. RNA was extracted from spermatozoa of 74 volunteers (39 patients with idiopathic AZS and 35 controls with normal fertility), and relative gene expression analysis was performed by quantitative PCR. We used SNORD48 as a normaliser gene, and quantification was calculated by 2^-ΔΔCt method. The expression of miR-4484 and miR-4461 was not detected in the spermatozoa of cases and controls. However, miR-4485-3p (p = .006) was significantly downregulated in the AZS men compared with the controls, but the miR-4463 expression was not significantly different between the two groups (p = .5). Bioinformatic analysis identified three target genes for miR-4485-3p (DNAH1, KIT and PARK7) that are related to male infertility. In conclusion, the downregulation of miR-4485-3p was associated with idiopathic AZS, which could be a molecular link between mitochondrial dysfunction and AZS.

Implicating androgen excess in propagating metabolic disease in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) has been traditionally perceived as a reproductive disorder due to its most common presentation with menstrual dysfunction and infertility. However, it is now clear that women with PCOS are at increased risk of metabolic dysfunction, from impaired glucose tolerance and type 2 diabetes mellitus to nonalcoholic fatty liver disease and cardiovascular disease. PCOS is characterised by androgen excess, with cross-sectional data showing that hyperandrogenism is directly complicit in the development of metabolic complications. Recent studies have also shown that C11-oxy _C19 androgens are emerging to be clinically and biochemically significant in PCOS, thus emphasising the importance of understanding the impact of both classic and C11-oxy _C19 androgens on women's health. Here we discuss androgen metabolism in the context of PCOS, and dissect the role played by androgens in the development of metabolic disease through their effects on metabolic target tissues in women.

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.

Grape Seed Procyanidin B2 Protects Porcine Ovarian Granulosa Cells against Oxidative Stress-Induced Apoptosis by Upregulating let-7a Expression

Oxidative stress is a causal factor and key promoter of all kinds of reproductive disorders related to granulosa cell (GC) apoptosis that acts by dysregulating the expression of related genes. Various studies have suggested that grape seed procyanidin B2 (GSPB2) may protect GCs from oxidative injury, though the underlying mechanisms are not fully understood. Therefore, whether the beneficial effects of GSPB2 are associated with microRNAs, which have been suggested to play a critical role in GC apoptosis by regulating the expression of protein-coding genes, was investigated in this study. The results showed that GSPB2 treatment protected GCs from a H₂O₂-induced apoptosis, as detected by an MTT assay and TUNEL staining, and increased let-7a expression in GCs. Furthermore, let-7a overexpression markedly increased cell viability and inhibited H₂O₂-induced GC apoptosis. Furthermore, the overexpression of let-7a reduced the upregulation of Fas expression in H₂O₂-treated GCs at the mRNA and protein levels. Dual-luciferase reporter assay results indicated that let-7a directly targets the Fas 3′-UTR. Furthermore, the overexpression of let-7a enhanced the protective effects of GSPB2 against GC apoptosis induced by H₂O₂. These results indicate that GSPB2 inhibits H₂O₂-induced apoptosis of GCs, possibly through the upregulation of let-7a.

Hyperandrogenism and Metabolic Syndrome Are Associated With Changes in Serum-Derived microRNAs in Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) remains one of the most common endocrine disorder in premenopausal women with an unfavorable metabolic risk profile. Here, we investigate whether biochemical hyperandrogenism, represented by elevated serum free testosterone, resulted in an aberrant circulating microRNA (miRNAs) expression profile and whether miRNAs can identify those PCOS women with metabolic syndrome (MetS). Accordingly, we measured serum levels of miRNAs as well as biochemical markers related to MetS in a case-control study of 42 PCOS patients and 20 Controls. Patients were diagnosed based on the Rotterdam consensus criteria and stratified based on serum free testosterone levels (≥0.034 nmol/l) into either a normoandrogenic (n = 23) or hyperandrogenic (n = 19) PCOS group. Overall, hyperandrogenic PCOS women were more insulin resistant compared to normoandrogenic PCOS women and had a higher prevalence of MetS. A total of 750 different miRNAs were analyzed using TaqMan Low-Density Arrays. Altered levels of seven miRNAs (miR-485-3p, -1290, -21-3p, -139-3p, -361-5p, -572, and -143-3p) were observed in PCOS patients when compared with healthy Controls. Stratification of PCOS women revealed that 20 miRNAs were differentially expressed between the three groups. Elevated serum free testosterone levels, adjusted for age and BMI, were significantly associated with five miRNAs (miR-1290, -20a-5p, -139-3p, -433-3p, and -361-5p). Using binary logistic regression and receiver operating characteristic curves (ROC), a combination panel of three miRNAs (miR-361-5p, -1225-3p, and -34-3p) could correctly identify all of the MetS cases within the PCOS group. This study is the first to report comprehensive miRNA profiling in different subgroups of PCOS women with respect to MetS and suggests that circulating miRNAs might be useful as diagnostic biomarkers of MetS for a different subset of PCOS.

Role of microRNA in the Pathogenesis of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most typical metabolic syndrome in women of reproductive age, with a high prevalence and an increased risk of long-term complications. PCOS mainly manifests as hyperandrogenism (HA), ovulatory dysfunction, and polycystic ovaries, in addition to being relevant to infertility, insulin resistance (IR), obesity, lipid abnormalities, and chronic low-grade inflammation. The etiology of this syndrome remains largely unknown. microRNAs (miRNAs), small, noncoding RNAs (nearly 22 nucleotides long), regulate gene expression at the posttranscriptional level. Abnormal miRNA levels are closely associated with the occurrence of diseases, such as diabetes, cancers, and atherosclerosis, and miRNAs can be used as predictors and diagnostic biomarkers for cancer. Interestingly, the roles of miRNAs in PCOS pathology have attracted considerable attention in recent years. Research has established that alterations in miRNA expression in women with PCOS compared with healthy women may act as noninvasive biomarkers and new therapeutic targets in PCOS. This article aims to summarize the latest research on the relationship between miRNAs and the clinical manifestations of PCOS while also providing a few mechanisms based on previous studies. Understanding the relationship between miRNAs and PCOS will provide guidance for researchers to further explore the complexity and heterogeneity of PCOS.

HNRNPA2/B1 is upregulated in endocrine-resistant LCC9 breast cancer cells and alters the miRNA transcriptome when overexpressed in MCF-7 cells

MicroRNAs are dysregulated in breast cancer. Heterogeneous Nuclear Ribonucleoprotein A2/B1 (HNRNPA2/B1) is a reader of the N(6)-methyladenosine (m6A) mark in primary-miRNAs (pri-miRNAs) and promotes DROSHA processing to precursor-miRNAs (pre-miRNAs). We examined the expression of writers, readers, and erasers of m6A and report that HNRNPA2/B1 expression is higher in tamoxifen-resistant LCC9 breast cancer cells as compared to parental, tamoxifen-sensitive MCF-7 cells. To examine how increased expression of HNRNPA2/B1 affects miRNA expression, HNRNPA2/B1 was transiently overexpressed (~5.4-fold) in MCF-7 cells for whole genome miRNA profiling (miRNA-seq). 148 and 88 miRNAs were up- and down-regulated, respectively, 48 h after transfection and 177 and 172 up- and down-regulated, respectively, 72 h after transfection. MetaCore Enrichment analysis identified progesterone receptor action and transforming growth factor β (TGFβ) signaling via miRNA in breast cancer as pathways downstream of the upregulated miRNAs and TGFβ signaling via SMADs and Notch signaling as pathways of the downregulated miRNAs. GO biological processes for mRNA targets of HNRNPA2/B1-regulated miRNAs included response to estradiol and cell-substrate adhesion. qPCR confirmed HNRNPA2B1 downregulation of miR-29a-3p, miR-29b-3p, and miR-222 and upregulation of miR-1266-5p, miR-1268a, miR-671-3p. Transient overexpression of HNRNPA2/B1 reduced MCF-7 sensitivity to 4-hydroxytamoxifen and fulvestrant, suggesting a role for HNRNPA2/B1 in endocrine-resistance.

The role of MiRNA in polycystic ovary syndrome (PCOS)

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

MiRNA-99a can regulate proliferation and apoptosis of human granulosa cells via targeting IGF-1R in polycystic ovary syndrome

PURPOSE

We aimed to evaluate the regulation of miR-99a to the biological functions of granulosa cells in polycystic ovary syndrome (PCOS) via targeting IGF-1R.

METHODS

We collected aspirated follicular fluid in both patients with and without PCOS. Granulosa cells (GCs) were isolated through Percoll differential centrifugation to detect both miR-99a and IGF-1R expressions. We further transfected COV434 cells with miR-99a mimics to establish a miRNA-99a (miR-99a) overexpression model. We explored the regulation of miR-99a to the proliferation and apoptosis of human GCs via IGF-1R in COV434. The effect of different insulin concentrations on miR-99a expression was also evaluated.

RESULTS

MiR-99a was significantly downregulated while IGF-1R was upregulated in patients with PCOS. MiR-99a can regulate IGF-1R on a post-transcriptional level. After transfection of miR-99a mimics, the proliferation rate was decreased and apoptosis rate was increased significantly in COV434. Exogenous insulin-like growth factor 1 (IGF-1) treatment could reverse the effect of miR-99a. MiR-99a was negatively and dose-dependently regulated by insulin in vitro.

CONCLUSIONS

MiR-99a expression was downregulated in patients with PCOS, the degree of which may be closely related to insulin resistance and hyperinsulinemia. MiR-99a could attenuate proliferation and promote apoptosis of human GCs through targeting IGF-1R, which could partly explain the abnormal folliculogenesis in PCOS.

Non-targeted profiling of circulating microRNAs in women with polycystic ovary syndrome (PCOS): effects of obesity and sex hormones

PURPOSE

Circulating micro-ribonucleic acids (miRNAs) are small noncoding RNA molecules that influence gene transcription. We conducted the present profiling study to characterize the expression of circulating miRNAs in lean and obese patients with polycystic ovary syndrome (PCOS), the most common endocrine and metabolic disorder in premenopausal women.

BASIC PROCEDURES

We selected 11 control women, 12 patients with PCOS and 12 men so that they were similar in terms of body mass index. Five control women, 6 men and 6 patients with PCOS had normal weight whereas 6 subjects per group were obese. We used miRCURY LNA™ Universal RT microRNA PCR for miRNA profiling.

MAIN FINDINGS

The expression of 38 miRNAs and was different between subjects with PCOS and male and female controls. The differences in 15 miRNAs followed a pattern suggestive of androgenization characterized by expression levels that were similar in patients with PCOS and men but were different compared with those of control women. The expression of 13 miRNAs in women with PCOS was similar to that of control women and different compared with the expression observed in men, suggesting sexual dimorphism and, lastly, we observed 5 miRNAs that were expressed differently in women with PCOS compared with both men and control women, suggesting a specific abnormality in expression associated with the syndrome. Obesity interacted with the differences in several of these miRNAs, and the expression levels of many of them correlated with the hirsutism score, sex hormones and/or indexes of obesity, adiposity and metabolic dysfunction.

PRINCIPAL CONCLUSIONS

The present results suggest that several serum miRNAs are influenced by PCOS, sex hormones and obesity. Our findings may guide the targeted search of miRNAs as clinically relevant markers for PCOS and its association with obesity and metabolic dysfunction in future studies.

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

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

Serum miRNAs in women affected by hyperandrogenic polycystic ovary syndrome: the potential role of miR-155 as a biomarker for monitoring the estroprogestinic treatment

MicroRNAs can be used as very efficient circulating biomarkers. The role of microRNAs in polycystic ovary syndrome (PCOS) and the effects of antiandrogen therapy on microRNA expression is still not fully understood. A panel of serum microRNAs were retrotranscribed via looped reverse primer transcription specific for each miRNA and quantified via probe specific RT-PCR in 16 Caucasian hyperandrogenic PCOS women selected according to the Rotterdam criteria and in a subset of seven patients after four months of sequential reverse antiandrogenic therapy. All women recruited underwent an oral glucose tolerance test (OGTT) and a baseline total cholesterol, high density lipoproteins cholesterol, triglycerides, AST and ALT dosage. In the follicular phase women were evaluated for total testosterone, Δ4-androstenedione, DHEAS, 17OHpg, FSH, LH, and 17-β-E2. The AUC_2hglucose, ISI Matsuda, oral disposition index (DIo) and visceral adipose index (VAI) were also calculated. We suggest that miR-155 might have a role as biomarker in hyperandrogenic PCOS patients to monitor the effect of antiandrogen therapy.

Ovarian extracellular MicroRNAs as the potential non-invasive biomarkers: An update

Through the reproductive system, it has been realized that the microRNAs (miRNAs) have emerged as one of the principal post-transcriptional gene regulators of the diverse developmental processes. The ovary, as a dynamic organ, co-ordinates follicle recruitment, selection, and ovulation, in which miRNAs play the central role almost in its all functions. Deregulation of these developmental procedures in ovary could lead to the ovarian dysfunction, infertility, decrease in the assisted reproductive treatment (ART) outcome, and death in some patients with ovarian cancer. In recent years, detection of ovarian extracellular miRNAs in body fluids such as follicular fluid and serum/plasma has opened a new era in the biomarker discovery field. Here through the present review, different aspects of the potential and proposed involvement of the extracellular miRNAs in both physiologic and pathologic contexts of the ovary have been discussed. Moreover, the researchers have addressed the relevant findings, challenges, and issues which associated with the extracellular miRNAs in the ovarian microenvironments to provide the better insight into understanding the molecular mechanisms which were involved in the pathophysiologic conditions. Finally, a comprehensive survey of the gaps has been discussed to hopefully shed new light and perspective on the development of the novel diagnostic and therapeutic platforms in the clinic.

Pathway and network-based analysis of genome-wide association studies and RT-PCR validation in polycystic ovary syndrome

The purpose of this study was to identify promising candidate genes and pathways in polycystic ovary syndrome (PCOS). Microarray dataset GSE345269 obtained from the Gene Expression Omnibus database includes 7 granulosa cell samples from PCOS patients, and 3 normal granulosa cell samples. Differentially expressed genes (DEGs) were screened between PCOS and normal samples. Pathway enrichment analysis was conducted for DEGs using ClueGO and CluePedia plugin of Cytoscape. A Reactome functional interaction (FI) network of the DEGs was built using ReactomeFIViz, and then network modules were extracted, followed by pathway enrichment analysis for the modules. Expression of DEGs in granulosa cell samples was measured using quantitative RT-PCR. A total of 674 DEGs were retained, which were significantly enriched with inflammation and immune-related pathways. Eight modules were extracted from the Reactome FI network. Pathway enrichment analysis revealed significant pathways of each module: module 0, Regulation of RhoA activity and Signaling by Rho GTPases pathways shared ARHGAP4 and ARHGAP9; module 2, GlycoProtein VI-mediated activation cascade pathway was enriched with RHOG; module 3, Thromboxane A2 receptor signaling, Chemokine signaling pathway, CXCR4-mediated signaling events pathways were enriched with LYN, the hub gene of module 3. Results of RT-PCR confirmed the finding of the bioinformatic analysis that ARHGAP4, ARHGAP9, RHOG and LYN were significantly upregulated in PCOS. RhoA-related pathways, GlycoProtein VI-mediated activation cascade pathway, ARHGAP4, ARHGAP9, RHOG and LYN may be involved in the pathogenesis of PCOS.

Roles of miR‑4463 in H2O2‑induced oxidative stress in human umbilical vein endothelial cells

Oxidative stress is implicated in the pathophysiology of vascular diseases, including atherosclerosis, aneurysm and arteriovenous fistula. A previous study from our lab suggested that microRNA (miR)-4463 may be involved in the pathogenesis of vascular disease; however, the roles of oxidative stress in the molecular mechanisms underlying the actions of miR-4463 in vascular disease have yet to be elucidated. The aim of the present study was to investigate the role of miR-4463 in hydrogen peroxide (H₂O₂)-induced oxidative stress in human umbilical vein endothelial cells (HUVECs). Reverse transcription-quantitative polymerase chain reaction was used to assess the expression levels of miR-4463 in HUVECs treated with various concentrations of H₂O₂. Flow cytometry was used to evaluate the percentage of apoptotic cells, and the protein expression levels of the apoptotic markers cleaved (C)-caspase3, poly (adenosine diphosphate-ribose) polymerase 1 (PARP1), B cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and X-linked inhibitor of apoptosis protein (XIAP) were determined using western blot analysis. The results demonstrated that the apoptotic rate of HUVECs was increased following treatment with H₂O₂ in a concentration-dependent manner, and the expression of miR-4463 was also upregulated in a dose-dependent manner. Following transfection with miR-4463 mimics, the levels of malondialdehyde and reactive oxygen species were increased in HUVECs, with a corresponding increase in the apoptotic rate. Furthermore, western blot analysis revealed that the protein expression levels of C-caspase3, PARP1 and Bax were upregulated, whereas the levels of Bcl-2 and XIAP were downregulated. In conclusion, the present findings suggested that the upregulation of miR-4463 may enhance H₂O₂-induced oxidative stress and promote apoptosis in HUVECs in vitro.

Abnormality of Klotho Signaling Is Involved in Polycystic Ovary Syndrome

This study investigated the involvement of the klotho-associated signaling in the apoptosis of granulosa cells (GCs) from the ovaries of patients with polycystic ovary syndrome (PCOS) and PCOS animals. Primary GCs were obtained from 26 healthy women and 43 women with PCOS. The PCOS animal model was established by the injection of dehydroepiandrosterone (DHEA). Klotho protein and associated microRNA expression in human primary GCs and rats' ovarian tissues were measured by Western blot and real-time polymerase chain reaction, respectively. Results showed that significantly lower miR-126-5p and miR-29a-5p microRNA expressions, higher klotho protein expression, lower insulin growth factor 1 (IGF-1R) and Wnt family member 1 (Wnt1) protein expressions, and lower Akt phosphorylation at Ser⁴⁷³ and Thr³⁰⁸ residues were observed in the GCs from patients with PCOS and the ovarian tissues of PCOS rats compared to that in GCs from healthy women and ovarian tissues of normal control rats, respectively. Knockdown of klotho gene expression normalized IGF-1R and Wnt1 protein expressions and Akt phosphorylation in GCs from patients with PCOS and the ovarian tissues from PCOS rats; it also blocked the effects of insulin on apoptosis and proliferation in GCs from patients with PCOS and inhibited caspase-3 activity in ovarian tissues of PCOS rats. Knockdown of klotho gene expression increased the pregnancy rate in DHEA-treated female rats and increased the body weight of their newborns through normalizing the ovarian function and decreasing the formation of cystic follicles. In conclusion, the miR-126-5p, miR-29a-5p/klotho/insulin-IGF-1, Wnt, and Akt signal pathway may be involved in the apoptosis of GCs and subsequent development of PCOS.

Which origin for polycystic ovaries syndrome: Genetic, environmental or both?

Polycystic ovaries syndrome (PCOS), the most common female endocrine disorder, affects 7-10% of women of childbearing age. It includes ovarian hyperandrogenism, impaired follicular maturation, anovulation and subfertility. Insulin resistance, although present in most cases, is not necessary for diagnosis. It increases hyperandrogenism and long-term metabolic, cardiovascular and oncological risks. The origin of hyperandrogenism and hyperinsulinemia has a genetic component, as demonstrated by familial aggregation studies and recent identification of associated genomic variants, conferring a particular susceptibility to the syndrome. However, experimental and epidemiological evidences also support a developmental origin via a deleterious foetal environment, concerning the endocrine status (foetal hyperandrogenism), the nutritional level (intrauterine growth retardation), or the toxicological exposure (endocrine disruptors). Epigenetic changes recently reported in the literature as associated with PCOS, enhance this hypothesis of foetal reprogramming of the future adult ovarian function by environmental factors. Better characterisation of these genetic, epigenetic, or environmental factors, could lead to earlier prevention and more efficient treatments.

The potential value of microRNA-4463 in the prognosis evaluation in hepatocellular carcinoma

The purpose of this study is to measure the expression of microRNA-4463 and microRNA-6087 between normal persons and patients with hepatocellular carcinoma (HCC), and to clarify the meaning of them in the prognosis evaluation in HCC. Forty-five samples from healthy people and patients, who had been diagnosed with hepatocellular carcinoma before any treatment, were collected to study respectively. Real-time PCR was used to detect the expression of miRNA-4463 and miRNA-6087 in the serum of control group and hepatocellular carcinoma patients. The expression of miR-4463 in the serum of HCC patients was significantly higher than that in control group (P < 0.05), and the expression level was independent of gender, tumor size, cell types, stages, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) and HBsAg status (P > 0.05). But there was a significant difference of different level of AFP in HCC (P < 0.05), and the difference between the group of AFP lower than 400 ug/l and the control group is statistically significant (P < 0.05). Besides, the survival time had showed a significant difference at the high and low expression levels (P < 0.05). But the expression level of miRNA-6087 was no difference in HCC and control group. The disorder of miRNA-4463 occurred in HCC, even the AFP level doesn't rises. What's more, patients who get the high level of miRNA-4463 seem to have a shorter survival time. And it contributes great to the prognostic evaluation. This is the first study to illustrate the potential significance of miRNA-4463 in the prognosis in HCC.

Profiles of miRNAs in serum in severe acute drug induced liver injury and their prognostic significance

BACKGROUND & AIMS

Drug induced liver injury (DILI) is challenging because of the lack of biomarkers to predict mortality. Our aim was to describe miRNA changes in sera of subjects with acute idiosyncratic DILI and determine if levels of miRNAs were associated with 6 month mortality.

METHODS

Clinical data and sera were collected from subjects enrolled in the Drug Induced Liver Injury Network prospective study. miRNAs were isolated from serum obtained from 78 subjects within 2 weeks of acute DILI and followed up for 6 months or longer. miRNAs were compared to 40 normal controls and 6 month survivors vs non-survivors.

RESULTS

The mean age of the DILI cohort was 48 years, and 55% were female. Eleven (14.1%) subjects died, 10 within 6 months of DILI onset, 5 (45%) liver related. Lower levels of miRNAs-122, -4463 and -4270 were associated with death within 6 months (P<.05). None of the subjects with miRNA-122 greater than the median value died within 6 months for a sensitivity of 100% and specificity of 57%. In subjects with a serum albumin <2.8 g/dL and miR-122<7.89 RFU the sensitivity, specificity, positive and negative predictive values for death within 6 months were 100%, 57%, 38% and 100% respectively.

CONCLUSIONS

Serum miRNA-122 combined with albumin accurately identified subjects who died within 6 months of drug induced liver injury. If confirmed prospectively, miRNA-122 and albumin may be useful in identifying patients at high risk for mortality or liver transplantation.

Circulating MicroRNAs in Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage

Background

Delayed cerebral infarction (DCI) is a major cause of morbidities after aneurysmal subarachnoid hemorrhage (SAH) and typically starts at day 4 to 7 after initial hemorrhage. MicroRNAs (miRNAs) play an important role in posttranscriptional gene expression control, and distinctive patterns of circulating miRNA changes have been identified for some diseases. We aimed to investigate miRNAs that characterize SAH patients with DCI compared with those without DCI.

Methods and Results

Circulating miRNAs were collected on day 7 after SAH in healthy, SAH‐free controls (n=20), SAH patients with DCI (n=20), and SAH patients without DCI (n=20). We used the LASSO (least absolute shrinkage and selection operator) method of regression analysis to characterize miRNAs associated with SAH patients with DCI compared with those without DCI. In the 28 dysregulated miRNAs associated with DCI and SAH, we found that a combination of 4 miRNAs (miR‐4532, miR‐4463, miR‐1290, and miR‐4793) could differentiate SAH patients with DCI from those without DCI with an area under the curve of 100% (95% CI 1.000–1.000, P<0.001). This 4‐miRNA combination could also distinguish SAH patients with or without DCI from healthy controls with areas under the curve of 99.3% (95% CI 0.977–1.000, P<0.001) and 82.0% (95% CI 0.685–0.955, P<0.001), respectively.

Conclusions

We found a 4‐miRNA combination that characterized SAH patients with DCI. The findings could guide future mechanistic study to develop therapeutic targets.

Chinese herbal medicine for subfertile women with polycystic ovarian syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is one of the most common reproductive endocrinology abnormalities, and affects 5% to 10% of women of reproductive age. Western medicines, such as oral contraceptives, insulin sensitizers and laparoscopic ovarian drilling (LOD), have been used to treat PCOS. Recently, many studies have been published that consider Chinese herbal medicine (CHM) as an alternative treatment for women with PCOS.

OBJECTIVES

To assess the efficacy and safety of CHM for subfertile women with PCOS.

SEARCH METHODS

We searched sources, including the following databases, from inception to 9 June 2016: the Cochrane Gynaecology and Fertility Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Allied and Complementary Medicine (AMED), PsycINFO, Chinese National Knowledge Infrastructure (CNKI), VIP, Wanfang and trial registries. In addition, we searched the reference lists of included trials and contacted experts in the field to locate trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that considered the use of CHM for the treatment of subfertile women with PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened appropriate trials for inclusion, assessed the risk of bias in included studies and extracted data. We contacted primary study authors for additional information. We conducted meta-analyses. We used the odds ratios (ORs) to report dichotomous data, with 95% confidence intervals (CI). We assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods.

MAIN RESULTS

We included five RCTs with 414 participants. The comparisons in the included trials were as follows: CHM versus clomiphene, CHM plus clomiphene versus clomiphene (with or without ethinyloestradiol cyproterone acetate (CEA)), CHM plus follicle aspiration plus ovulation induction versus follicle aspiration plus ovulation induction alone, and CHM plus laparoscopic ovarian drilling (LOD) versus LOD alone. The overall quality of the evidence for most comparisons was very low.None of the included studies reported live birth rate, and only one study reported data on adverse events.When CHM was compared with clomiphene (with or without LOD in both arms), there was no evidence of a difference between the groups in pregnancy rates (odds ratio (OR) 1.98, 95% confidence interval (CI) 0.78 to 5.06; two studies, 90 participants, I² statistic = 0%, very low quality evidence). No study reported data on adverse events. When CHM plus clomiphene was compared with clomiphene (with or without CEA), there was low quality evidence of a higher pregnancy rate in the CHM plus clomiphene group (OR 2.62, 95% CI 1.65 to 4.14; three RCTs, 300 women, I² statistic = 0%,low quality evidence). No data were reported on adverse events.When CHM with follicle aspiration and ovulation induction was compared with follicle aspiration and ovulation induction alone, there was no evidence of a difference between the groups in pregnancy rates (OR 1.60, 95% CI 0.46 to 5.52; one study, 44 women, very low quality evidence), severe luteinized unruptured follicle syndrome (LUFS) (OR 0.60, 95% CI 0.06 to 6.14; one study, 44 women, very low quality evidence), ovarian hyperstimulation syndrome (OHSS) (OR 0.16, 95% CI 0.00 to 8.19; one study, 44 women, very low quality evidence) or multiple pregnancy (OR 0.60, 95% CI 0.06 to 6.14; one study, 44 women, very low quality evidence).When CHM with LOD was compared with LOD alone, there was no evidence of a difference between the groups in rates of pregnancy (OR 3.50, 95% CI 0.72 to 17.09; one study, 30 women, very low quality evidence), No data were reported on adverse events.There was no evidence of a difference between any of the comparison groups for any other outcomes. The quality of the evidence for all other comparisons and outcomes was very low. The main limitations in the evidence were failure to report live birth or adverse events, failure to describe study methods in adequate detail and imprecision due to very low event rates and wide CIs.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support the use of CHM for women with PCOS and subfertility. No data are available on live birth, and there is no consistent evidence to indicate that CHM influences fertility outcomes. However there is very limited low quality evidence to suggest that the addition of CHM to clomiphene may improve pregnancy rates. There is insufficient evidence on adverse effects to indicate whether CHM is safe.

The Role of Serum MicroRNA-6767-5p as a Biomarker for the Diagnosis of Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder, and the underlying molecular mechanisms are not clear. To date, few studies have been conducted on the altered expression of serum microRNAs (miRNAs) in women with PCOS. The present study was performed to examine the role of the serum miRNA as a biomarker for the diagnosis of PCOS and its relationship with metabolic and reproductive traits.

Methods

A cross-sectional comparison was made in 21 women with PCOS and age- and body mass index (BMI)- matched 21 healthy women in an academic center laboratory between December 2008 and October 2010. We selected miRNAs that were more than 1.5-fold up-regulated or less than 0.67-fold down-regulated in women with PCOS compared with controls using the SurePrint G3 Human miRNA Microarray. Subsequently, we validated the relative expression of the miRNAs using TaqMan quantitative real-time polymerase chain reaction (RT-qPCR) assays.

Results

Serum miRNA-4522, miRNA-324-3p, and miRNA-6767-5p were down-regulated in women with PCOS compared with controls in the microarray analysis. Among these miRNAs, serum miRNA-6767-5p was validated (fold change in women with PCOS/controls = 0.39, P-value<0.05) by RT-qPCR. The miRNA-6767-5p was negatively associated with fasting glucose (β = -0.370) and positively associated with the number of menses per year (β = 0.383) after adjustment for age and BMI (Ps<0.05). Genes targeted by miRNA-6767-5p were involved in the cell cycle and the immune system.

Conclusions

Serum miRNA-6767-5p may be a novel candidate as a molecular biomarker in the diagnosis of PCOS and may participate in the development of the metabolic and reproductive traits of PCOS.

Identification of several circulating microRNAs from a genome-wide circulating microRNA expression profile as potential biomarkers for impaired glucose metabolism in polycystic ovarian syndrome

This study aimed to detect serum microRNAs (miRNAs) differentially expressed between polycystic ovary syndrome (PCOS) patients with impaired glucose metabolism (IGM), PCOS patients with normal glucose tolerance (NGT), and healthy controls. A TaqMan miRNA array explored serum miRNA profiles as a pilot study, then selected miRNAs were analyzed in a validation cohort consisting of 65 PCOS women with IGM, 65 PCOS women with NGT, and 45 healthy women The relative expression of miR-122, miR-193b, and miR-194 was up-regulated in PCOS patients compared with controls, whereas that of miR-199b-5p was down-regulated. Furthermore, miR-122, miR-193b, and miR-194 were increased in the PCOS-IGM group compared with the PCOS-NGT group. Multiple linear regression analyses revealed that miR-193b and body mass index contributed independently to explain 43.7 % (P < 0.0001) of homeostasis model assessment-insulin resistance after adjustment for age. Investigation of diagnostic values confirmed the optimal combination of BMI and miR-193b to explore the possibility of IGM in PCOS women with area under the curve of 0.752 (95 % CI 0.667-0.837, P < 0.001). Bioinformatics analysis indicated that the predicted target functions of these miRNAs mainly involved glycometabolism and ovarian follicle development pathways, including the insulin signaling pathway, the neurotrophin signaling pathway, the PI3K-AKT signaling pathway, and regulation of actin cytoskeleton. This study expands our knowledge of the serum miRNA expression profiles of PCOS patients with IGM and the predicted target signal pathways involved in disease pathophysiology.

Transforming growth factor-β1 increases lysyl oxidase expression by downregulating MIR29A in human granulosa lutein cells

Lysyl oxidase (LOX), a key enzyme in the formation and stabilization of the extracellular matrix, is expressed in granulosa cells and plays a critical role in the regulation of granulosa cell differentiation, oocyte maturation and ovulation. To date, the regulation of LOX expression in human granulosa cells remains largely unknown. In this study, using primary and immortalized human granulosa lutein cells, we demonstrated that transforming growth factor (TGF)-β1 (TGFB1) upregulated LOX expression and downregulated microRNA-29a (MIR29A) expression via a TGF-β type I receptor-mediated signaling pathway. Additionally, we showed that MIR29A downregulated the expression of LOX in both types of cells. Furthermore, the downregulation of MIR29A contributed to the TGFB1-induced increase in LOX expression because the inhibition of MIR29A with a MIR29A inhibitor not only reversed the MIR29A-induced downregulation of LOX but also enhanced the TGFB1-induced upregulation of LOX. Our findings suggest that TGFB1 and MIR29A may play essential roles in the regulation of extracellular matrix remodeling during the periovulatory phase.

Circulating microRNAs in follicular fluid, powerful tools to explore in vitro fertilization process

Circulating or “extracellular” microRNAs (miRNAs) detected in biological fluids, could be used as potential diagnostic and prognostic biomarkers of several disease, such as cancer, gynecological and pregnancy disorders. However, their contributions in female infertility and in vitro fertilization (IVF) remain unknown. This study investigated the expression profiles of five circulating miRNAs (let-7b, miR-29a, miR-30a, miR-140 and miR-320a) in human follicular fluid from 91 women with normal ovarian reserve and 30 with polycystic ovary syndrome (PCOS) and their ability to predict IVF outcomes. The combination of FF miR-30a, miR-140 and let-7b expression levels discriminated between PCOS and normal ovarian reserve with a specificity of 83.8% and a sensitivity of 70% (area under the ROC curve, AUC = 0.83 [0.73–0.92]; p < 0.0001). FF samples related to low number of mature oocytes (≤2) contained significant less miR-320a levels than those related to a number of mature oocytes >2 (p = 0.04). Moreover, FF let-7b predicted the development of expanded blastocysts with 70% sensitivity and 64.3% specificity (AUC = 0.67 [0.54–0.79]; p = 0.02) and FF miR-29a potential to predict clinical pregnancy outcome reached 0.68 [0.55–0.79] with a sensitivity of 83.3% and a specificity of 53.5% (p = 0.01). Therefore, these miRNAs could provide new helpful biomarkers to facilitate personalized medical care during IVF.

[Circulating nucleic acids and infertility]

Circulating nucleic acids (cell-free DNA and microRNAs) have for particularity to be easily detectable in the biological fluids of the body. Therefore, they constitute biomarkers of interest in female and male infertility care. Indeed, in female, they can be used to detect ovarian reserve disorders (polycystic ovary syndrome and low functional ovarian reserve) as well as to assess follicular microenvironment quality. Moreover, in men, their expression levels can vary in case of spermatogenesis abnormalities. Finally, circulating nucleic acids have also the ability to predict successfully the quality of in vitro embryo development. Their multiple contributions during assisted reproductive technology (ART) make of them biomarkers of interest, for the development of new diagnostic and/or prognostic tests, applied to our specialty. Circulating nucleic acids would so offer the possibility of personalized medical care for infertile couples in ART.

Polycystic Ovary Syndrome-Epigenetic Mechanisms and Aberrant MicroRNA

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age affecting various functions including reproduction and metabolism. This syndrome is associated with increased prevalence of subclinical cardiovascular disease as well as endometrial and ovarian cancer. This syndrome is highly heterogeneous and it is not yet clear which factors are responsible for the development of a particular phenotype. Current research has shown that the interaction of susceptible and protective genomic variants under the influence of environmental factors can modify the clinical presentation via epigenetic modifications. MicroRNA (miRNA) are regulators of gene expression. Altered miRNA expression has been associated with various diseases such as diabetes, insulin resistance, inflammation, and cancer. Several miRNA have been identified in PCOS. This review examines the role of epigenetics and miRNA in the pathophysiology of this complex disease process.

microRNA in Human Reproduction

microRNAs constitute a large family of approximately 21-nucleotide-long, noncoding RNAs. They emerged more than 20 years ago as key posttranscriptional regulators of gene expression. The regulatory role of these small RNA molecules has recently begun to be explored in the human reproductive system. microRNAs have been shown to play an important role in control of reproductive functions, especially in the processes of oocyte maturation, folliculogenesis, corpus luteum function, implantation, and early embryonic development. Knockout of Dicer, the cytoplasmic enzyme that cleaves the pre-miRNA to its mature form, results in postimplantation embryonic lethality in several animal models, attributing to these small RNA vital functions in reproduction and development. Another intriguing characteristic of microRNAs is their presence in body fluids in a remarkably stable form that is protected from endogenous RNase activity. In this chapter we will describe the current knowledge on microRNAs, specifically relating to human gonadal cells. We will focus on their role in the ovarian physiologic process and ovulation dysfunction, regulation of spermatogenesis and male fertility, and putative involvement in human normal and aberrant trophoblast differentiation and invasion through the process of placentation.