Role of Non-coding RNAs in the Pathogenesis of Endometriosis

Selection of reference miRNAs for RT-qPCR assays in endometriosis menstrual blood-derived mesenchymal stem cells

Choosing appropriate reference genes or internal controls to normalize RT-qPCR data is mandatory for the interexperimental reproducibility of gene expression data obtained by RT-qPCR in most studies, including those on endometriosis. Particularly for miRNAs, the choice for reference genes is challenging because of their physicochemical and biological characteristics. Moreover, the retrograde menstruation theory, mesenchymal stem cells in menstrual blood (MenSCs), and changes in post-transcriptional regulatory processes through miRNAs have gained prominence in the scientific community as important players in endometriosis. Therefore, we originally explored the stability of 10 miRNAs expressions as internal control candidates in conditions involving the two-dimensional culture of MenSCs from healthy women and patients with endometriosis. Here, we applied multiple algorithms (geNorm, NormFinder, Bestkeeper, and delta Ct) to screen reference genes and assessed the comprehensive stability classification of miRNAs using RefFinder. Pairwise variation calculated using geNorm identified three miRNAs as a sufficient number of reference genes for accurate normalization. MiR-191-5p, miR-24-3p, and miR-103a-3p were the best combination for suitable gene expression normalization. This study will benefit similar research, but is also attractive for regenerative medicine and clinics that use MenSCs, miRNA expression, and RT-qPCR.

Genetic variants in miR-146a and miR-196a2 in endometriosis: a Brazilian study

OBJECTIVE

The aim of this study was to determine the allelic and genotypic frequencies of the polymorphisms, rs2910164 miR-146a and rs11614913 miR-196a2, by investigating their association with endometriosis.

METHODS

This is a case-control study performed with approximately 120 women. The polymorphisms were determined by real-time polymerase chain reaction. For the statistical analysis, the chi-square and logistic regression tests were used.

RESULTS

There were no significant differences in the genotype and allele frequencies of rs2910164 and rs11614913 between cases and controls. The frequencies in both polymorphisms are in accordance with Hardy-Weinberg equilibrium regarding miR-146a (patients: χ2=1.64, p=0.20; controls: χ2=0.25, p=0.62) and miR-196a2 (patients: χ2=0.58, p=0.44; controls: χ2=2.78, p=0.10). No relationship was observed between rs2910164 and rs11614913 and endometriosis in the inheritance models analyzed.

CONCLUSION

In this study, our results show that the studied polymorphisms are not implicated in the development of endometriosis.

The roles of chromatin regulatory factors in endometriosis

PURPOSE

Endometriosis is an estrogen-dependent inflammatory disease and one of the most common gynecological diseases in women of reproductive age. The aim of the review was to explore the relationship between the chromatin regulatory factors and endometriosis.

METHODS

By searching for literature on chromatin regulators and endometriosis in PuMed. Finally, 98 documents were selected.

RESULTS

Chromatin regulators (CRs) are essential epigenetic regulatory factors that can regulate chromatin structure changes and are usually divided into three categories: DNA methylation compounds, histone modification compounds, and chromatin remodeling complexes. Noncoding RNAs are also chromatin regulators and can form heterochromatin by binding to protein complexes. Chromatin regulators cause abnormal gene expression by regulating chromatin structure, thereby affecting the occurrence and development of endometriosis.

CONCLUSION

This review summarizes the participation of chromatin regulators in the mechanisms of endometriosis, and these changes in related chromatin regulators provide a comprehensive reference for diagnosis and treatment of endometriosis.

Ferroptosis and oxidative stress in endometriosis: A systematic review of the literature

BACKGROUND

Endometriosis (EMT) a common gynecological condition in women, an inflammatory disease characterized by the presence of endometrial tissue on organs and tissues in the pelvis, and is mainly associated with chronic pelvic pain and infertility. As the etiology has not been fully elucidated, current treatment is limited to surgery, hormones and painkillers, with more side effects and difficulty in achieving long-term relief. Oxidative stress manifests itself as an overproduction of reactive oxygen species, which has an integral impact in the pathology of female reproductive disorders. In this review, we evaluate the mechanisms of iron overload-induced oxidative stress and ferroptosis in EMT and their pathophysiological implications.

METHODS

Because the etiology has not been fully elucidated, current treatments are limited to surgery, hormones, and painkillers, which have many side effects and are difficult to achieve long-term relief.

RESULTS

We interpreted that antioxidants as well as ferroptosis inducers show promising results in the treatment of EMT, but their application in this population needs to be further investigated.

CONCLUSION

In combination with the interpretation of previous studies, it was shown that iron overload is present in the peritoneal fluid, endometriotic lesions, peritoneum and macrophages in the abdominal cavity. However, the programmed cellular ferroptosis associated with iron overload is resisted by endometriotic foci, which is critical to the pathophysiology of EMT with local iron overload and inflammation.

Interactions between miRNAs and the Wnt/β-catenin signaling pathway in endometriosis

Endometriosis is a disease characterized by the ectopic growth of endometrial tissue (glands and stroma) outside the confines of the uterus and often involves vital organs such as the intestines and urinary system. Endometriosis is considered a refractory disease owing to its enigmatic etiology, propensity for recurrence following conservative or surgical interventions, and the absence of radical treatment and long-term management. In recent years, the incidence of endometriosis has gradually increased, rendering it a pressing concern among women of childbearing age. A more profound understanding of its pathogenesis can significantly improve prognosis. Recent research endeavors have spotlighted the molecular mechanisms by which microRNAs (miRNAs) regulate the occurrence and progression of endometriosis. Many miRNAs have been reported to be aberrantly expressed in the affected tissues of both patients and animal models. These miRNAs actively participate in the regulation of inflammatory reactions, cellular proliferation, angiogenesis, and tissue remodeling. Their capacity to modulate crucial signaling pathways, such as the Wnt/β-catenin signaling pathway, reinforces their potential utility as diagnostic markers or therapeutic agents for endometriosis. In this review, we provide the latest insights into the role of miRNAs that interact with the Wnt/β-catenin pathway to regulate the biological behaviors of endometriosis cells and disease-related symptoms, such as pain and infertility. We hope that this review will provide novel insights and promising targets for innovative therapies addressing endometriosis.

Association of endometriosis with Sjögren's syndrome: Genetic insights (Review)

Patients with a history of endometriosis have an increased risk of developing various autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and celiac disease. There is a potential association between endometriosis and an increased susceptibility for Sjögren's syndrome (SS). SS is a common chronic, inflammatory, systemic, autoimmune, multifactorial disease of complex pathology, with genetic, epigenetic and environmental factors contributing to the development of this condition. It occurs in 0.5‑1% of the population, is characterized by the presence of ocular dryness, lymphocytic infiltrations and contributes to neurological, gastrointestinal, vascular and dermatological manifestations. Endometriosis is an inflammatory, estrogen‑dependent, multifactorial, heterogeneous gynecological disease, affecting ≤10% of reproductive‑age women. It is characterized by the occurrence of endometrial tissue outside the uterine cavity, mainly in the pelvic cavity, and is associated with pelvic pain, dysmenorrhea, deep dyspareunia and either subfertility or infertility. It is still unclear whether SS appears as a secondary response to endometriosis, or it is developed due to any potential shared mechanisms of these conditions. The aim of the present review was to explore further the biological basis only of the co‑occurrence of these disorders but not their association at clinical basis, focusing on the analysis of the partially shared genetic background between endometriosis and SS, and the clarification of the possible similarities in the underlying pathogenetic mechanisms and the relevant molecular pathways.

The landscape of non-coding RNAs in the immunopathogenesis of Endometriosis

Endometriosis is a complex disorder that is characterized by the abnormal growth of endometrial-like tissue outside the uterus. It is associated with chronic inflammation, severe pelvic pain, infertility, and significantly reduced quality of life. Although the exact mechanism of endometriosis remains unknown, inflammation and altered immunity are considered key factors in the immunopathogenesis of the disorder. Disturbances of immune responses result in reduced clearance of regurgitated endometrial cells, which elicits oxidative stress and progression of inflammation. Proinflammatory mediators could affect immune cells' recruitment, fate, and function. Reciprocally, the activation of immune cells can promote inflammation. Aberrant expression of non-coding RNA (ncRNA) in patient and animal lesions could be suggestive of their role in endometriosis establishment. The engagement of these RNAs in regulating diverse biological processes, including inflammatory responses and activation of inflammasomes, altered immunity, cell proliferation, migration, invasion, and angiogenesis are widespread and far-reaching. Therefore, ncRNAs can be identified as a determining candidate regulating the inflammatory responses and immune system. This review aims in addition to predict the role of ncRNAs in the immunopathogenesis of endometriosis through regulating inflammation and altered immunity based on previous studies, it presents a comprehensive view of inflammation role in the pathogenesis of endometriosis.

A comprehensive overview of exosome lncRNAs: emerging biomarkers and potential therapeutics in endometriosis

Endometriosis is a gynecological condition that significantly impacting women's daily lives. In recent years, the incidence of endometriosis has been rising yearly and is now an essential contributor to female infertility. Exosomes are extracellular vesicles (EVs) that carry long noncoding RNA (lncRNA) and shield lncRNA from the outside environment thanks to their vesicle-like structure. The role of exosome-derived lncRNAs in endometriosis is also receiving more study as high-throughput sequencing technology develops. Several lncRNAs with variable expression may be crucial to the emergence and growth of endometriosis. The early diagnosis of endometriosis will be considerably improved by further high specificity and sensitivity Exosome lncRNA screening. Exosomes assist lncRNAs in carrying out their roles, offering a new target for creating endometriosis-specific medications. In order to serve as a reference for clinical research on the pathogenesis, diagnosis, and treatment options of endometriosis, this paper covers the role of exosome lncRNAs in endometriosis and related molecular mechanisms.

METTL3-dependent m6A methylation facilitates uterine receptivity and female fertility via balancing estrogen and progesterone signaling

Infertility is a worldwide reproductive health problem and there are still many unknown etiologies of infertility. In recent years, increasing evidence emerged and confirmed that epigenetic regulation played a leading role in reproduction. However, the function of m⁶A modification in infertility remains unknown. Here we report that METTL3-dependent m⁶A methylation plays an essential role in female fertility via balancing the estrogen and progesterone signaling. Analysis of GEO datasets reveal a significant downregulation of METTL3 expression in the uterus of infertile women with endometriosis or recurrent implantation failure. Conditional deletion of Mettl3 in female reproductive tract by using a Pgr-Cre driver results in infertility due to compromised uterine endometrium receptivity and decidualization. m⁶A-seq analysis of the uterus identifies the 3'UTR of several estrogen-responsive genes with METTL3-dependent m⁶A modification, like Elf3 and Celsr2, whose mRNAs become more stable upon Mettl3 depletion. However, the decreased expression levels of PR and its target genes, including Myc, in the endometrium of Mettl3 cKO mice indicate a deficiency in progesterone responsiveness. In vitro, Myc overexpression could partially compensate for uterine decidualization failure caused by Mettl3 deficiency. Collectively, this study reveals the role of METTL3-dependent m⁶A modification in female fertility and provides insight into the pathology of infertility and pregnancy management.

Downregulation of DROSHA: Could It Affect miRNA Biogenesis in Endometriotic Menstrual Blood Mesenchymal Stem Cells?

Menstrual blood mesenchymal stem cells (MenSCs) have gained prominence in the endometriosis scientific community, given their multifunctional roles in regenerative medicine as a noninvasive source for future clinical applications. In addition, changes in post-transcriptional regulation via miRNAs have been explored in endometriotic MenSCs with a role in modulating proliferation, angiogenesis, differentiation, stemness, self-renewal, and the mesenchymal-epithelial transition process. In this sense, homeostasis of the miRNA biosynthesis pathway is essential for several cellular processes and is related to the self-renewal and differentiation of progenitor cells. However, no studies have investigated the miRNA biogenesis pathway in endometriotic MenSCs. In this study, we profiled the expression of eight central genes for the miRNA biosynthesis pathway under experimental conditions involving a two-dimensional culture of MenSCs obtained from healthy women (n = 10) and women with endometriosis (n = 10) using RT-qPCR and reported a two-fold decrease in DROSHA expression in the disease. In addition, miR-128-3p, miR-27a-3p, miR-27b-3p, miR-181a-5p, miR-181b-5p, miR-452-3p, miR-216a-5p, miR-216b-5p, and miR-93-5p, which have been associated with endometriosis, were identified through in silico analyses as negative regulators of DROSHA. Because DROSHA is essential for miRNA maturation, our findings may justify the identification of different profiles of miRNAs with DROSHA-dependent biogenesis in endometriosis.

Association of endometriosis with cardiovascular disease: Genetic aspects (Review)

Cardiovascular disease (CVD) comprises a broad spectrum of pathological conditions that affect the heart or blood vessels, including sequelae that arise from damaged vasculature in other organs of the body, such as the brain, kidneys or eyes. Atherosclerosis is a chronic inflammatory disease of the arterial intima and is the primary cause of coronary artery disease, peripheral vascular disease, heart attack, stroke and renal pathology. It represents a leading cause of mortality worldwide and the loss of human productivity that is marked by an altered immune response. Endometriosis is a heritable, heterogeneous, common gynecological condition influenced by multiple genetic, epigenetic and environmental factors, affecting up to 10% of the female population of childbearing age, causing pain and infertility; it is characterized by the ectopic growth of endometrial tissue outside the uterine cavity. Of note, epidemiological data obtained thus far have suggested a link between endometriosis and the risk of developing CVD. The similarities observed in specific molecular and cellular pathways of endometriosis and CVD may be partially explained by a shared genetic background. The present review presents and discusses the shared genetic factors which have been reported to be associated with the development of both disorders.

Endometriosis-associated infertility diagnosis based on saliva microRNA signatures

RESEARCH QUESTION

Can a saliva-based miRNA signature for endometriosis-associated infertility be designed and validated by analysing the human miRNome?

DESIGN

The prospective ENDOmiARN study (NCT04728152) included 200 saliva samples obtained between January 2021 and June 2021 from women with pelvic pain suggestive of endometriosis. All patients underwent either laparoscopy, magnetic resonance imaging, or both. Patients diagnosed with endometriosis were allocated to one of two groups according to their fertility status. Data analysis consisted of identifying a set of miRNA biomarkers using next-generation sequencing, and development of a saliva-based miRNA signature of infertility among patients with endometriosis based on a random forest model.

RESULTS

Among the 153 patients diagnosed with endometriosis, 24% (n = 36) were infertile and 76% (n = 117) were fertile. Small RNA-sequencing of the 153 saliva samples yielded approximately 3712 M raw sequencing reads (from ∼13.7 M to ∼39.3 M reads/sample). Of the 2561 known miRNAs, the feature selection method generated a signature of 34 miRNAs linked to endometriosis-associated infertility. After validation, the most accurate signature model had a sensitivity, specificity and area under the curve of 100%.

CONCLUSION

A saliva-based miRNA signature for endometriosis-associated infertility is reported. Although the results still require external validation before using the signature in routine practice, this non-invasive tool is likely to have a major effect on care provided to women with endometriosis.

Analysis of Long Non-Coding RNA (lncRNA) UCA1, MALAT1, TC0101441, and H19 Expression in Endometriosis

Endometriosis is a disease of complex etiology. Hormonal, immunological, and environmental factors are involved in its formation. In recent years, special attention has been paid to genetic mechanisms that can have a significant impact on the increased incidence of endometriosis. The study aimed to analyze the expression of four long non-coding RNA (lncRNA) genes, UCA1, MALAT1, TC0101441, and H19, in the context of the risk of developing endometriosis. The material for genetic testing for the expression of lncRNA genes were tissue slices embedded in paraffin blocks from patients with endometriosis (n = 100) and the control group (n = 100). Gene expression was determined by the RT-PCR technique. The expression of the H19 gene in endometriosis patients was statistically significantly lower than in the control group. A statistically significant association was found between H19 gene expression in relation to The Revised American Society for Reproductive Medicine classification of endometriosis (rASRM) in the group of patients with endometriosis. Research suggests that H19 expression plays an important role in the pathogenesis of endometriosis.

Epigenetic regulation and T-cell responses in endometriosis – something other than autoimmunity

Endometriosis is defined as the presence of endometrial-like glands and stroma located outside the uterine cavity. This common, estrogen dependent, inflammatory condition affects up to 15% of reproductive-aged women and is a well-recognized cause of chronic pelvic pain and infertility. Despite the still unknown etiology of endometriosis, much evidence suggests the participation of epigenetic mechanisms in the disease etiopathogenesis. The main rationale is based on the fact that heritable phenotype changes that do not involve alterations in the DNA sequence are common triggers for hormonal, immunological, and inflammatory disorders, which play a key role in the formation of endometriotic foci. Epigenetic mechanisms regulating T-cell responses, including DNA methylation and posttranslational histone modifications, deserve attention because tissue-resident T lymphocytes work in concert with organ structural cells to generate appropriate immune responses and are functionally shaped by organ-specific environmental conditions. Thus, a failure to precisely regulate immune cell transcription may result in compromised immunological integrity of the organ with an increased risk of inflammatory disorders. The coexistence of endometriosis and autoimmunity is a well-known occurrence. Recent research results indicate regulatory T-cell (Treg) alterations in endometriosis, and an increased number of highly active Tregs and macrophages have been found in peritoneal fluid from women with endometriosis. Elimination of the regulatory function of T cells and an imbalance between T helper cells of the Th1 and Th2 types have been reported in the endometria of women with endometriosis-associated infertility. This review aims to present the state of the art in recognition epigenetic reprogramming of T cells as the key factor in the pathophysiology of endometriosis in the context of T-cell-related autoimmunity. The new potential therapeutic approaches based on epigenetic modulation and/or adoptive transfer of T cells will also be outlined.

Endometriosis Associated-miRNome Analysis of Blood Samples: A Prospective Study

The aim of our study was to describe the bioinformatics approach to analyze miRNome with Next Generation Sequencing (NGS) of 200 plasma samples from patients with and without endometriosis. Patients were prospectively included in the ENDO-miRNA study that selected patients with pelvic pain suggestive of endometriosis. miRNA sequencing was performed using an Novaseq6000 sequencer (Illumina, San Diego, CA, USA). Small RNA-seq of 200 plasma samples yielded ~4228 M raw sequencing reads. A total of 2633 miRNAs were found differentially expressed. Among them, 8.6% (n = 229) were up- or downregulated. For these 229 miRNAs, the F1-score, sensitivity, specificity, and AUC ranged from 0-88.2%, 0-99.4%, 4.3-100%, and 41.5-68%, respectively. Utilizing the combined bioinformatic and NGS approach, a specific and broad panel of miRNAs was detected as being potentially suitable for building a blood signature of endometriosis.

Long non-coding RNA DHRS4 antisense RNA 1 inhibits ectopic endometrial cell proliferation, migration, and invasion in endometriosis by regulating microRNA-139-5p expression

Endometriosis is an estrogen-dependent chronic gynecological syndrome. Recent studies have shown that long non-coding RNAs participate in the pathogenesis and development of endometriosis. This study aimed to explore the mechanisms of DHRS4 antisense RNA 1 (DHRS4-AS1) in endometriosis. Dual-luciferase reporter assays were conducted to determine the relationship between DHRS4-AS1, microRNA (miR)-139-5p, and arrestin domain-containing 3 (ARRDC3). Furthermore, the expression of DHRS4-AS1 and miR-139-5p in ectopic endometrial stromal cells (EC-ESCs) and endometriosis tissues was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry, and Transwell assays were performed to evaluate the proliferation, apoptosis, and migration and invasion of EC-ESCs, respectively. Western blotting and RT-qPCR were further utilized to determine cleaved-Caspase 3, Caspase 3, and matrix metalloproteinase 9 (MMP-9) expression levels. Compared with the EN group, DHRS4-AS1 levels were lower and miR-139-5p levels were higher in EC-ESCs and tissues obtained from patients with endometriosis. Functional assays validated that DHRS4-AS1 targets miR-139-5p, with ARRDC3 being a downstream target of miR-139-5p. Rescue experiments demonstrated that DHRS4-AS1 inhibited EC-ESC proliferation, migration, and invasion, but promoted apoptosis, by targeting miR-139-5p in endometriosis. cleaved-Caspase3 expression level and the cleaved-Caspase 3/Caspase 3 ratio increased, while the expression levels of MMP-9 decreased, after transfection with DHRS4-AS1 overexpression plasmids; however, the effects induced by DHRS4-AS1 overexpression could be partially reversed by co-transfection with the miR-139-5p mimic. The current study demonstrates that the DHRS4-AS1/miR-139-5p/ARRDC3 axis participates in the regulation of EC-ESC function.

MicroRNome analysis generates a blood-based signature for endometriosis

Endometriosis, characterized by endometrial-like tissue outside the uterus, is thought to affect 2-10% of women of reproductive age: representing about 190 million women worldwide. Numerous studies have evaluated the diagnostic value of blood biomarkers but with disappointing results. Thus, the gold standard for diagnosing endometriosis remains laparoscopy. We performed a prospective trial, the ENDO-miRNA study, using both Artificial Intelligence (AI) and Machine Learning (ML), to analyze the current human miRNome to differentiate between patients with and without endometriosis, and to develop a blood-based microRNA (miRNA) diagnostic signature for endometriosis. Here, we present the first blood-based diagnostic signature obtained from a combination of two robust and disruptive technologies merging the intrinsic quality of miRNAs to condense the endometriosis phenotype (and its heterogeneity) with the modeling power of AI. The most accurate signature provides a sensitivity, specificity, and Area Under the Curve (AUC) of 96.8%, 100%, and 98.4%, respectively, and is sufficiently robust and reproducible to replace the gold standard of diagnostic surgery. Such a diagnostic approach for this debilitating disorder could impact recommendations from national and international learned societies.

Differential Expression and Bioinformatics Analysis of tRF/tiRNA in Endometriosis Patients

Background. Endometriosis (EMs) is a benign chronic condition that tends to recur in women of childbearing age, with an incidence of approximately 10%. It is a multifactorial disease for which the pathogenesis is currently unclear. This study is aimed at investigating the expression and clinical significance of tRNA-derived small RNA (tsRNA), a novel noncoding small RNA with potential regulatory functions, in endometriosis. Methods. The tRF/tiRNA expression profiles in endometrial tissues from three pairs of endometriosis patients and controls were detected by tRF&tiRNA PCR microarray technology and then verified by quantitative real-time polymerase chain reaction (qPCR). The target genes and target sites of TRF396, tiRNA-5030-GlnTTG-3, TRF308, and TRF320 were predicted by miRanda, and the network diagram of their interaction with miRNA was drawn. The impact of tRNA-derived fragments on the pathogenesis of endometriosis was analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Results. Two upregulated and 19 downregulated tRNA-derived fragments were identified. The qRT-PCR results of 2 upregulated and 2 downregulated RNA-derived fragments were consistent with the RNA Seq data. The OR2B4 gene related to TRF396, the DGAT1 gene related to tiRNA-5030-GlnTTG-3, the KLF16 gene of TRF308, and the RNF213 gene of TRF320 had significant correlations. Gene Ontology and pathway analysis showed that the target genes of TRF396 and tiRNA-5030-GlnTTG-3 were mainly involved in the intrinsic components of the membrane and the overall composition of the membrane in cell components; molecular functions mainly involve olfactory conduction and G protein-coupled receptor activity. In the biological process, it was mainly involved in the detection of sensory stimuli. The target genes of TRF308 and TRF320 were mainly involved in the intracellular part; molecular functions are mainly related to DNA binding transcription factor activity and protein binding and mainly related to biological regulation of biological processes. Pathway analysis showed that the RAP1 signaling pathway and the AXON GUIDANCE signaling pathway may participate in the progression of endometriosis. Conclusion. The differential expression of tRF/tiRNA in endometriosis may be related to the pathogenesis of endometriosis. Furthermore, tRF/tiRNA may be a biomarker for the diagnosis and treatment of EMs in the future.

MiR-143-3p facilitates motility and invasiveness of endometriotic stromal cells by targeting VASH1/TGF-β signaling

Endometriosis is a benign gynecological disease. Accumulating evidence has revealed the participation of dysregulated miRNAs in the progression of endometriosis. Here, the function and molecular mechanism of miR-143-3p in endometriosis were investigated. The levels of vasohibin 1 (VASH1) and miR-143-3p in endometrial tissues and endometriotic stromal cells (ESCs) were detected by RT-qPCR. Migrative and invasive phenotypes of ESCs were tested by Transwell assays. The protein expression of VASH1, TGF-β signaling markers, and epithelial to mesenchymal transition (EMT) markers was examined by western blotting. The targeted relationship between miR-143-3p and VASH1 was confirmed by bioinformatics analysis and luciferase reporter assay. We found that miR-143-3p expression was significantly upregulated in ectopic endometrial tissues compared to that in eutopic and normal endometrial tissues. MiR-143-3p knockdown restrained EMT process, invasive and migrative behaviors of ESCs. Mechanically, miR-143-3p targeted VASH1 and negatively regulated VASH1. VASH1 downregulation reserved the effects of miR-143-3p knockdown in ESCs. MiR-143-3p activated TGF-β signaling via targeting VASH1. Furthermore, activation of TGF-β signaling counteracted the miR-143-3p knockdown-caused suppression of migration, invasion and EMT process in ESCs. Overall, miR-143-3p activates TGF-β signaling by targeting VASH1 to facilitate migration and invasion of ESCs.

Long noncoding RNA ADAMTS9-AS1 represses ferroptosis of endometrial stromal cells by regulating the miR-6516-5p/GPX4 axis in endometriosis

Endometriosis (EMs) is one of the most frequent diseases of reproductive-age women and is characterized by the growth of endometrial tissues beyond the uterus. The enhanced proliferative and migratory potential of endometrial stromal cells (ESCs) plays an important role in the progression of EMs. Mounting studies have demonstrated that long noncoding RNAs (lncRNAs) exert an important role in regulating the development and progression of EMs. Given the aberrant expression of lncRNA ADAMTS9-AS1 in ectopic endometrium (ecEM), we investigated the biological effect of ADAMTS9-AS1 on ESC proliferation and migration and explored the underlying mechanism. The current data showed that ADAMTS9-AS1 expression was significantly upregulated in ecEM compared with eutopic endometrium (euEM) in patients with EMs and in a murine model of EMs. Functionally, ADAMTS9-AS1 knockdown in ectopic ESCs (EESCs) decreased cell viability and migration, whereas ADAMTS9-AS1 overexpression in normal ESCs (NESCs) enhanced cell viability and migration. More importantly, the effect of ADAMTS9-AS1 inhibition on decreasing ESC viability was significantly blocked by ferrostatin-1 (Fer-1, a ferroptosis inhibitor), and ADAMTS9-AS1 overexpression repressed erastin (a ferroptosis activator)-induced cell death. Furthermore, the regulatory role of ADAMTS9-AS1 in ferroptosis was defined and evidenced by increased reactive oxygen species (ROS) levels and malonyl dialdehyde (MDA) content and decreased expression of glutathione peroxidase 4 (GPX4) after ADAMTS9-AS1 inhibition. Mechanistically, ADAMTS9-AS1 functioned as a competing endogenous RNA (ceRNA) by sponging miR-6516-5p to derepress the expression of GPX4, the critical repressor of ferroptosis. Taken together, these results demonstrate that upregulated ADAMTS9-AS1 accelerates ESC proliferation and migration by regulating miR-6516-5p/GPX4-dependent ferroptosis and may be a potential target for the treatment of EMs.

Salivary MicroRNA Signature for Diagnosis of Endometriosis

BACKGROUND

Endometriosis diagnosis constitutes a considerable economic burden for the healthcare system with diagnostic tools often inconclusive with insufficient accuracy. We sought to analyze the human miRNAome to define a saliva-based diagnostic miRNA signature for endometriosis.

METHODS

We performed a prospective ENDO-miRNA study involving 200 saliva samples obtained from 200 women with chronic pelvic pain suggestive of endometriosis collected between January and June 2021. The study consisted of two parts: (i) identification of a biomarker based on genome-wide miRNA expression profiling by small RNA sequencing using next-generation sequencing (NGS) and (ii) development of a saliva-based miRNA diagnostic signature according to expression and accuracy profiling using a Random Forest algorithm.

RESULTS

Among the 200 patients, 76.5% (n = 153) were diagnosed with endometriosis and 23.5% (n = 47) without (controls). Small RNA-seq of 200 saliva samples yielded ~4642 M raw sequencing reads (from ~13.7 M to ~39.3 M reads/sample). Quantification of the filtered reads and identification of known miRNAs yielded ~190 M sequences that were mapped to 2561 known miRNAs. Of the 2561 known miRNAs, the feature selection with Random Forest algorithm generated after internally cross validation a saliva signature of endometriosis composed of 109 miRNAs. The respective sensitivity, specificity, and AUC for the diagnostic miRNA signature were 96.7%, 100%, and 98.3%.

CONCLUSIONS

The ENDO-miRNA study is the first prospective study to report a saliva-based diagnostic miRNA signature for endometriosis. This could contribute to improving early diagnosis by means of a non-invasive tool easily available in any healthcare system.

Clues for Improving the Pathophysiology Knowledge for Endometriosis Using Plasma Micro-RNA Expression

The pathophysiology of endometriosis remains poorly understood. The aim of the present study was to investigate functions and pathways associated with the various miRNAs differentially expressed in patients with endometriosis. Plasma samples of the 200 patients from the prospective "ENDO-miRNA" study were analyzed and all known human miRNAs were sequenced. For each miRNA, sensitivity, specificity, and ROC AUC values were calculated for the diagnosis of endometriosis. miRNAs with an AUC ≥ 0.6 were selected for further analysis. A comprehensive review of recent articles from the PubMed, Clinical Trials.gov, Cochrane Library, and Web of Science databases was performed to identify functions and pathways associated with the selected miRNAs. In total, 2633 miRNAs were found in the patients with endometriosis. Among the 57 miRNAs with an AUC ≥ 0.6: 20 had never been reported before; one (miR-124-3p) had previously been observed in endometriosis; and the remaining 36 had been reported in benign and malignant disorders. miR-124-3p is involved in ectopic endometrial cell proliferation and invasion and plays a role in the following pathways: mTOR, STAT3, PI3K/Akt, NF-κB, ERK, PLGF-ROS, FGF2-FGFR, MAPK, GSK3B/β-catenin. Most of the remaining 36 miRNAs are involved in carcinogenesis through cell proliferation, apoptosis, and invasion. The three main pathways involved are Wnt/β-catenin, PI3K/Akt, and NF-KB. Our results provide evidence of the relation between the miRNA profiles of patients with endometriosis and various signaling pathways implicated in its pathophysiology.

Molecular Signatures Correlated With Poor IVF Outcomes: Insights From the mRNA and lncRNA Expression of Endometriotic Granulosa Cells

The outcomes of in vitro fertilization (IVF) for endometriotic women are significantly worse than for patients without ovarian endometriosis (OEM), as shown by fewer retrieved oocytes. However, the exact pathophysiological mechanism is still unknown. Thus, we conducted a prospective study that analyzed mRNA and lncRNA transcriptome between granulosa cells (GCs) from patients with fewer retrieved oocytes due to OEM and GCs from controls with male factor (MF) infertility using an RNA sequencing approach. We found a group of significantly differentially expressed genes (DEGs), including NR5A2, MAP3K5, PGRMC2, PRKAR2A, DEPTOR, ITGAV, KPNB1, GPC6, EIF3A, and SMC5, which were validated to be upregulated and negatively correlated with retrieved oocyte numbers in GCs of patients with OEM, while DUSP1 demonstrated the opposite. The molecular functions of these DEGs were mainly enriched in pathways involving mitogen-activated protein kinase (MAPK) signaling, Wnt signaling, steroid hormone response, apoptosis, and cell junction. Furthermore, we performed lncRNA analysis and identified a group of differentially expressed known/novel lncRNAs that were co-expressed with the validated DEGs and correlated with retrieved oocyte numbers. Co-expression networks were constructed between the DEGs and known/novel lncRNAs. These distinctive molecular signatures uncovered in this study are involved in the pathological regulation of ovarian reserve dysfunction in OEM patients.

CDKN2B-AS1 promotes the proliferation, clone formation, and invasion of nasopharyngeal carcinoma cells by regulating miR-98-5p/E2F2 axis

OBJECTIVE

To explore the effect of CDKN2B antisense RNA 1 (CDKN2B-AS1) on the proliferation, clone formation, and invasion of nasopharyngeal carcinoma (NPC) cells by regulating miR-98-5p/E2F transcription factor 2 (E2F2) axis.

METHODS

The expressions of CDKN2B-AS1, miR-98-5p, and E2F2 in NPC tissues and cell lines (SUNE-1, 5-8F, 6-10B, and HK-1) as well as in peritumoral normal tissues and cell line NP69 were determined by qRT-PCR. Subcellular localization of CDKN2B-AS1 was detected using the fluorescence in situ hybridization assay. The targeting relationships between CDKN2B-AS1 and miR-98-5p as well as between miR-98-5p and E2F2 were analyzed by the dual-luciferase reporter assay and RNA binding protein immunoprecipitation assay. The proliferation, clone formation and invasion of 5-8F cells were measured using the CCK-8 assay, Clone formation assay, and transwell assay, respectively.

RESULTS

CDKN2B-AS1 was highly expressed in NPC tissues and cells, whereas the expression of miR-98-5p decreased in the NPC tissues and cells. Silencing of CDKN2B-AS1 inhibited the proliferation, clone formation, and invasion of NPC cells (all P<0.05). CDKN2B-AS1 acted asceRNA of miR-98-5p, and miR-98-5p inhibitor could partially reverse the inhibitory effect of silencing CDKN2B-AS1 on NPC cells (all P<0.05). CDKN2B-AS1 upregulated E2F2 by inhibiting miR-98-5p, and the upregulation of E2F2 partially reversed the inhibitory effect of miR-98-5p overexpression on the NPC cells (all P<0.05).

CONCLUSION

CDKN2B-AS1, as a lncRNA, can regulate E2F2 by sponging miR-98-5p to promote the proliferation, clone formation, and invasion of NPC cells.

Circulating miRNAs Related to Epithelial-Mesenchymal Transitions (EMT) as the New Molecular Markers in Endometriosis

Endometriosis is a chronic gynecological disease defined by the presence of endometrial-like tissue found outside the uterus, most commonly in the peritoneal cavity. Endometriosis lesions are heterogenous but usually contain endometrial stromal cells and epithelial glands, immune cell infiltrates and are vascularized and innervated by nerves. The complex etiopathogenesis and heterogenity of the clinical symptoms, as well as the lack of a specific non-invasive diagnostic biomarkers, underline the need for more advanced diagnostic tools. Unfortunately, the contribution of environmental, hormonal and immunological factors in the disease etiology is insufficient, and the contribution of genetic/epigenetic factors is still fragmentary. Therefore, there is a need for more focused study on the molecular mechanisms of endometriosis and non-invasive diagnostic monitoring systems. MicroRNAs (miRNAs) demonstrate high stability and tissue specificity and play a significant role in modulating a range of molecular pathways, and hence may be suitable diagnostic biomarkers for the origin and development of endometriosis. Of these, the most frequently studied are those related to endometriosis, including those involved in epithelial–mesenchymal transition (EMT), whose expression is altered in plasma or endometriotic lesion biopsies; however, the results are ambiguous. Specific miRNAs expressed in endometriosis may serve as diagnostics markers with prognostic value, and they have been proposed as molecular targets for treatment. The aim of this review is to present selected miRNAs associated with EMT known to have experimentally confirmed significance, and discuss their utility as biomarkers in endometriosis.

ADSC Exosomes Mediate lncRNA-MIAT Alleviation of Endometrial Fibrosis by Regulating miR-150-5p

Background

Secondary infertility remains a major complication of endometrial fibrosis in women. The use of exosomes from adipose-derived mesenchymal stem cells (ADSCs) has shown promising results for the treatment of endometrial fibrosis. However, the mechanisms of action of ADSC-exosome (ADSC-Exo) therapy remain unclear.

Materials and Methods

An endometrial fibrosis model was established in mice treated with alcohol and endometrial epithelial cells (ESCs) treated with TGF-β1. ADSCs were isolated from Sprague Dawley (SD) rats, and exosomes were isolated from ADSCs using ExoQuick reagent. Exosomes were identified by transmission electron microscopy (TEM), NanoSight, and Western blot analysis. The expression level of lncRNA-MIAT was detected by qPCR analysis. Western blot analysis was carried out to determine the protein levels of fibrosis markers (TGFβR1, α-SMA, and CK19). A dual-luciferase reporter gene assay was used to verify the relationship between target genes. The endometrial tissues of the endometrial fibrosis model were stained with HE and Masson’s trichrome.

Results

ADSCs and ADSC-Exos were successfully isolated, and the expression level of lncRNA-MIAT was significantly down-regulated in endometrial tissue and the TGF-β1-induced ESC injury model, whereas ADSC-Exos increased the expression of lncRNA-MIAT in the TGF-β1-induced ESC model. Functionally, ADSC-Exo treatment repressed endometrial fibrosis in vivo and in vitro by decreasing the expression of hepatic fibrosis markers (α-SMA and TGFβR1) and increasing the expression of CK19. Moreover, miR-150-5p expression was repressed by lncRNA-MIAT in the TGF-β1-induced ESC injury model. The miR-150-5p mimic promoted TGF-β1-induced ESC fibrosis.

Conclusion

ADSC-Exos mediate lncRNA-MIAT alleviation of endometrial fibrosis by regulating miR-150-5p, which suggests that lncRNA-MIAT from ADSC-Exos may be a viable treatment for endometrial fibrosis.