Enhanced epithelial to mesenchymal transition (EMT) and upregulated MYC in ectopic lesions contribute independently to endometriosis

Unraveling pathogenesis, biomarkers and potential therapeutic agents for endometriosis associated with disulfidptosis based on bioinformatics analysis, machine learning and experiment validation

BACKGROUND

Endometriosis (EMs) is an enigmatic disease of yet-unknown pathogenesis. Disulfidptosis, a novel identified form of programmed cell death resulting from disulfide stress, stands a chance of treating diverse ailments. However, the potential roles of disulfidptosis-related genes (DRGs) in EMs remain elusive. This study aims to thoroughly explore the key disulfidptosis genes involved in EMs, and probe novel diagnostic markers and candidate therapeutic compounds from the aspect of disulfidptosis based on bioinformatics analysis, machine learning, and animal experiments.

RESULTS

Enrichment analysis on key module genes and differentially expressed genes (DEGs) of eutopic and ectopic endometrial tissues in EMs suggested that EMs was closely related to disulfidptosis. And then, we obtained 20 and 16 disulfidptosis-related DEGs in eutopic and ectopic endometrial tissue, respectively. The protein-protein interaction (PPI) network revealed complex interactions between genes, and screened nine and ten hub genes in eutopic and ectopic endometrial tissue, respectively. Furthermore, immune infiltration analysis uncovered distinct differences in the immunocyte, human leukocyte antigen (HLA) gene set, and immune checkpoints in the eutopic and ectopic endometrial tissues when compared with health control. Besides, the hub genes mentioned above showed a close correlation with the immune microenvironment of EMs. Furthermore, four machine learning algorithms were applied to screen signature genes in eutopic and ectopic endometrial tissue, including the binary logistic regression (BLR), the least absolute shrinkage and selection operator (LASSO), the support vector machine-recursive feature elimination (SVM-RFE), and the extreme gradient boosting (XGBoost). Model training and hyperparameter tuning were implemented on 80% of the data using a ten-fold cross-validation method, and tested in the testing sets which determined the excellent diagnostic performance of these models by six indicators (Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, Accuracy, and Area Under Curve). And seven eutopic signature genes (ACTB, GYS1, IQGAP1, MYH10, NUBPL, SLC7A11, TLN1) and five ectopic signature genes (CAPZB, CD2AP, MYH10, OXSM, PDLIM1) were finally identified based on machine learning. The independent validation dataset also showed high accuracy of the signature genes (IQGAP1, SLC7A11, CD2AP, MYH10, PDLIM1) in predicting EMs. Moreover, we screened 12 specific compounds for EMs based on ectopic signature genes and the pharmacological impact of tretinoin on signature genes was further verified in the ectopic lesion in the EMs murine model.

CONCLUSION

This study verified a close association between disulfidptosis and EMs based on bioinformatics analysis, machine learning, and animal experiments. Further investigation on the biological mechanism of disulfidptosis in EMs is anticipated to yield novel advancements for searching for potential diagnostic biomarkers and revolutionary therapeutic approaches in EMs.

Excess endocrine growth hormone in acromegaly promotes the aggressiveness and metastasis of triple-negative breast cancer

Pituitary adenoma-induced excess endocrine growth hormone (GH) secretion can lead to breast cancer development and metastasis. Herein, we used an acromegaly mouse model to investigate the role of excess endocrine GH on triple-negative breast cancer (TNBC) growth and metastasis. Additionally, we aimed to elucidate the molecular mechanism of transcription factor 20 (TCF20)/nuclear factor erythroid 2-related factor 2 (NRF2) signaling-mediated aggressiveness and metastasis of TNBC. Excess endocrine GH induced TCF20 activates the transcription of NRF2 and NRF2-target genes to facilitate TNBC metastasis. Inhibition of GH receptor (GHR) and TCF20 activity using the GHR antagonist or small-interfering RNA-induced gene knockdown resulted in reduced tumor volume and metastasis, suggesting that excess endocrine GH stimulates TCF20/NRF2 pathways in TNBC and promotes metastasis to the lung. GHR inhibitors present an effective therapeutic strategy to prevent TNBC cell growth and metastasis. Our findings revealed functional and mechanistic roles of the GH-TCF20-NRF2 signaling axis in TBNC progression.

Prefoldin-5 Expression Is Elevated in Eutopic and Ectopic Endometriotic Epithelium and Modulates Endometriotic Epithelial Cell Proliferation and Migration In Vitro

Endometriosis is a common disease among women of reproductive age in which endometrial tissue grows in ectopic localizations, primarily within the pelvic cavity. These ectopic "lesions" grow as well as migrate and invade underlying tissues. Despite the prevalence of the disease, an understanding of factors that contribute to these cellular attributes remains poorly understood. Prefoldin-5 (PFDN5) has been associated with both aberrant cell proliferation and migration, but a potential role in endometriosis is unknown. As such, the purpose of this study was to examine PFDN5 expression in endometriotic tissue. PFDN5 mRNA and protein were examined in ectopic (lesion) and eutopic endometrial tissue from women with endometriosis and in eutopic endometrium from those without endometriosis using qRT-PCR and immunohistochemistry, respectively, while function of PFDN5 in vitro was evaluated using cell count and migration assays. PFDN5 mRNA and protein were expressed in eutopic and ectopic endometrial tissue, predominantly in the glandular epithelium, but not in endometrium from control subjects. Expression of both mRNA and protein was variable among endometriotic eutopic and ectopic endometrial tissue but showed an overall net increase. Knockdown of PFDN5 by siRNA transfection of endometriotic epithelial 12Z cells was associated with reduced cell proliferation/survival and migration. PFDN5 is expressed in eutopic and ectopic glandular epithelium and may play a role in proliferation and migration of these cells contributing to disease pathophysiology.

Implication of biosignatures in the progression of endometriosis

Endometriosis is an estrogen-dependent chronic inflammatory disorder involving the placement and growth of endometrial tissue outside the uterine cavity. It is the most common multifactorial disease that affects the life quality of women in reproductive age. Due to its multicomponent nature, early diagnosis of the disease is challenging. Since many genetic, epigenetic alterations and non-genetic factors contribute to the pathology of endometriosis, devising a drug therapy that directly acts on the ectopic tissue is extremely difficult. Endometriosis is a hormone-driven disease with estrogen considered as a primary driver for the development of endometriotic lesions. This study aims to identify biosignatures involved in endometriosis with and without gonadotropin releasing hormone agonists (GnRHa). GnRHa is a short peptide analog of GnRH that causes inhibition of estrogen and androgen synthesis. Microarray based-gene expression profiling was performed on total RNA extracted from endometriotic tissue samples with and without GnRHa-treated patients already published in our previous paper. The untreated group were considered as the control. Genes were then selected for validation by quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR analysis confirmed significant downregulation in(p < 0.05) expression of DARC (p = 0.0042), CDH1 (p = 0.0027), CDH5 (p = 0.0283), ATP2A3 (p < 0.001), RGS5 (p = 0.0032), and CD36 (p = 0.0162) in endometriosis patients treated with GnRHa analogs. Although, CTNNAL1 (p = 0.0136) also showed significant results but there was upregulation in their expression levels after GnRHa treatment. Thus, an altered expression of these genes makes them a possible candidate determinant of endometriosis treated with GnRHa.

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.

MLLT11 Regulates Endometrial Stroma Cell Adhesion, Proliferation and Survival in Ectopic Lesions of Women with Advanced Endometriosis

MLLT11 is a gene implicated in cell differentiation and the development and progression of human cancers, but whose role in the pathogenesis of endometriosis is still unknown. Using quantitative RT-PCR and immunohistochemistry, we analyzed 37 women with and 33 women without endometriosis for differences in MLLT11 expression. We found that MLLT11 is reduced in the ectopic stroma cells of women with advanced stage endometriosis compared to women without endometriosis. MLLT11 knockdown in control stroma cells resulted in the downregulation of their proliferation accompanied by G1 cell arrest and an increase in the expression of p21 and p27. Furthermore, the knockdown of MLLT11 was associated with increased apoptosis resistance to camptothecin associated with changes in BCL2/BAX signaling. Finally, MLLT11 siRNA knockdown in the control primary stroma cells led to an increase in cell adhesion associated with the transcriptional activation of ACTA2 and TGFB2. We found that the cellular phenotype of MLLT11 knockdown cells resembled the phenotype of the primary endometriosis stroma cells of the lesion, where the levels of MLLT11 are significantly reduced compared to the eutopic stroma cells of women without the disease. Overall, our results indicate that MLLT11 may be a new clinically relevant player in the pathogenesis of endometriosis.

Development of an SPRi Test for the Quantitative Detection of Cadherin 12 in Human Plasma and Peritoneal Fluid

A new method for the determination of cadherin 12 (CDH12)-an adhesive protein that has a significant impact on the development, growth, and movement of cancer cells-was developed and validated. The method is based on a biosensor using surface plasmon resonance imaging (SPRi) detection. A quartz crystal microbalance was used to analyze the characteristics of the formation of successive layers of the biosensor, from the linker monolayer to the final capture of CDH12 from solution. The association equilibrium constant (KA = 1.66 × 1011 dm3 mol-1) and the dissociation equilibrium constant (KD = 7.52 × 10-12 mol dm-3) of the anti-CDH12 antibody-CDH12 protein complex were determined. The determined analytical parameters, namely the values determining the accuracy, precision, and repeatability of the method, do not exceed the permissible 20% deviations specified by the aforementioned institutions. The proposed method is also selective with respect to possible potential interferents, occurring in up to 100-fold excess concentration relative to the CDH12 concentration. The determined Limit of Quantification (LOQ = 4.92 pg mL-1) indicates the possibility of performing quantitative analysis in human plasma or peritoneal fluid without the need to concentrate the samples; however, particular attention should be paid to their storage conditions, as the analyte does not exhibit high stability. The Passing-Bablok regression model revealed good agreement between the reference method and the SPRi biosensor, with ρSpearman values of 0.961 and 0.925.

CXADR promote epithelial-mesenchymal transition in endometriosis by modulating AKT/GSK-3β signaling

Endometriosis is a benign high prevalent disease exhibiting malignant features. However, the underlying pathogenesis and key molecules of endometriosis remain unclear. By integrating and analysis of existing expression profile datasets, we identified coxsackie and adenovirus receptor (CXADR), as a novel key gene in endometriosis. Based on the results of immunohistochemistry (IHC), we confirmed significant down-regulation of CXADR in ectopic endometrial tissues obtained from women with endometriosis compared with healthy controls. Further in vitro investigation indicated that CXADR regulated the stability and function of the phosphatases and AKT inhibitors PHLPP2 (pleckstrin homology domain and leucine-rich repeat protein phosphatase 2) and PTEN (phosphatase and tensin homolog). Loss of CXADR led to phosphorylation of AKT and glycogen synthase kinase-3β (GSK-3β), which resulted in stabilization of an epithelial-mesenchymal transition (EMT) factor, SNAIL1 (snail family transcriptional repressor 1). Therefore, EMT processs was induced, and the proliferation, migration and invasion of Ishikawa cells were enhanced. Over-expression of CXADR showed opposite effects. These findings suggest a previously undefined role of AKT/GSK-3β signaling axis in regulating EMT and reveal the involvement of a CXADR-induced EMT, in pathogenic progression of endometriosis.

Assessment of BMP7, SMAD4, and CDH1 Expression Profile and Regulatory miRNA-542-3p in Eutopic and Ectopic Endometrium of Women with Endometriosis

Alterations in the expression of numerous genes and the miRNAs that are recognized as their regulators in the endometrial cells of women with endometriosis may disrupt the intracellular signaling pathways associated with epithelial–mesenchymal transition (EMT). So far, the functional role of BMP7 in endometrial physiology has been confirmed, especially in the context of fertility, but the role of the activation of a specific mechanism operating through the BMP–SMAD–CDH1 axis in the formation of endometrial lesions remains unexplored. The aim of this study was to evaluate the expression profile of miR-542-3p and the EMT markers (BMP7, SMAD4, CDH1) in matched eutopic endometrium (EUE) and ectopic endometrium (ECE) samples from women with endometriosis in relation to healthy women. The levels of expression of the studied genes and miRNA in peripheral blood mononuclear cells (PBMCs) obtained from women diagnosed with endometriosis and those without the disease were also evaluated. Fifty-four patients (n = 54: with endometriosis—n = 29 and without endometriosis—n = 25) were included in the study. A comparative analysis of the relative mean expression values (RQ) of the studied mRNA and miRNA assessed by RT-qPCR demonstrated downregulation of BMP7, SMAD4, and CDH1 expression in ectopic lesions and upregulation in the eutopic endometrium compared with the control group. In the eutopic tissue of women with endometriosis, miR-542-3p expression was similar to that of the control but significantly lower than in endometrial lesions. We also confirmed a trend towards a negative correlation between miR-542-3p and BMP7 in ectopic tissue, and in PBMC, a significant negative correlation of miR-542-3p with further BMP signaling genes, i.e., SMAD4 and CDH1, was observed. These results indicate that the miRNA selected by us may be a potential negative regulator of BMP7-SMAD4-CDH1 signaling associated with EMT. The different patterns of BMP7, SMAD4, and CDH1 gene expression in ECE, EUE, and the control endometrium observed by us suggests the loss of the endometrial epithelium phenotype in women with endometriosis and demonstrates their involvement in the pathogenesis and pathomechanism of this disease.

New concepts on the etiology of endometriosis

Endometriosis is a serious, chronic disorder where endometrial tissue grows outside the uterus, causing severe pelvic pain and infertility. It affects 11% of women. Endometriosis is a multifactorial disorder of unclear etiology, although retrograde menstruation plays a major role. It has a genetic component with over 40 genetic risk factors mapped, although their mechanism of action is still emerging. New evidence suggests a role for retrograde menstruation of endometrial stem/progenitor cells, now that identifying markers of these cells are available. Recent lineage tracing and tissue clearing microscopy and 3D reconstruction has provided new understanding of endometrial glandular structure, particularly the horizontal orientation and interconnection of basalis glands. New sequencing technologies, particularly whole genome DNA sequencing are revealing somatic mutations, including in cancer driver genes, in normal and eutopic endometrium of patients with endometriosis, as well as ectopic endometriotic lesions. Methylome sequencing is offering insight into the regulation of genes and the role of the environmental factors. Single cell RNA sequencing reveals the transcriptome of individual endometrial cells, shedding new light on the diversity and range of cellular subpopulations of the major cell types present in the endometrium and in endometriotic lesions. New endometrial epithelial organoid cultures replicating glandular epithelium are providing tractable models for studying endometriosis. Organoids derived from menstrual fluid offer a non-invasive source of endometrial tissue and a new avenue for testing drugs and developing personalized medicine for treating endometriosis. These new approaches are rapidly advancing our understanding of endometriosis etiology.

Identification of key modules and candidate genes associated with endometriosis based on transcriptome data via bioinformatics analysis

BACKGROUNDS

Endometriosis is a common disease in women, but the signaling pathways and genes involved remain unclear. This study screened genes that were differentially expressed in ectopic endometrium (EC) and eutopic endometrium (EU) in endometriosis and provided clues for subsequent experimental verification.

METHODS

Endometriosis samples were harvested from inpatients that underwent surgery from 2017 to 2019 with pathological evidence of endometriosis. We assessed the mRNA expression profiles in endometriosis and further conducted gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, Gene Set Enrichment Analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) to identify potential biomarkers in endometriosis. Finally, we further validated hub genes using public databases and immunohistochemistry assays.

RESULTS

The upregulated DEGs of ectopic endometrium from endometriosis patients were mainly involved in cell adhesion, MAPK signaling, PI3K-Akt signaling pathways, cytokine receptor interactions, and epithelial-mesenchymal transformation (EMT)-associated signaling pathways. The downregulated DEGs between ectopic endometrium and eutopic endometrium were related to decidualization-associated genes in endometriosis. The correlated gene modules in eutopic endometrial cells were mainly enriched in cell adhesion, embryo implantation and inflammation. The eutopic and ectopic endometrial lesions in endometriosis were involved in the EMT process. Furthermore, we identified 18 co-expression modules during WGCNA analysis. Hub genes in the pale turquoise module were FOSB, JUNB, ATF3, CXCL2, FOS, etc. Significantly enriched KEGG pathways included the TNF, MAPK, foxO, oxytocin, and p53 signaling pathways. Enrichment pathways were directly related to immune surveillance, stem cell self-renewal, and epithelial-mesenchymal transformation. Several pathways and modules of endometriosis are related to cancer-associated pathways, which substantiates the correlation between endometriosis and various gynecological tumors.

CONCLUSIONS

Endometriosis was tightly correlated with EMT and fibrosis mediated by inflammatory immunity, cytokines, estrogen, kinases and protooncogene through transcriptomics. Overall, our findings lay the groundwork for understanding the pathogenesis of endometriosis and its relationship with malignant transformation.

Upregulation of SPI1 in Ectopic Endometrium Contributes to an Invasive Phenotype

BACKGROUD AND AIM

Endometriosis is one of the most common gynecological diseases associated with chronic pelvic pain, infertility, and cancer. However, its molecular pathogenesis remains unclear. This study aimed to identify key genes involved in the pathogenesis of endometriosis.

METHODS

Bioinformatic analyses were perfomed to identify key differentially expressed genes (DEGs), transcription factors (TFs), and functionally enriched pathways. Effect of SPI1 on migration, invasion, expression of ADH1B, MYH11, and PLN were analyzed in human endometriotic cells.

RESULTS

By screening three transcriptome datasets from the GEO for overlapping DEGs between eutopic and ectopic endometria in patients with endometriosis, we found that the expression of ADH1B, MYH11, and PLN was markedly upregulated in the ectopic endometrium. Knockdown of ADH1B, MYH11, and PLN significantly inhibited the migration and invasion of human endometriotic 12Z cells. Additionally, gene set enrichment analysis revealed that epithelial-mesenchymal transition gene signature was positively correlated with ADH1B, MYH11, and PLN expression. Notably, the TF SPI1 was found to regulate the expression of these three genes in the endometriotic tissues and 12TZ cells. Moreover, SPI1 expression was associated with the invasion of endometriotic cells and was increased in the ectopic endometrium of patients with endometriosis.

CONCLUSION

These data suggest that SPI1 plays a key role in the progression of endometriosis by regulating ADH1B, MYH11, and PLN expression and may therefore serve as a potential prognostic and therapeutic factor for endometriosis.

Oestrogen-induced epithelial-mesenchymal transition (EMT) in endometriosis: Aetiology of vaginal agenesis in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome

Endometriosis occurs when endometrial-like tissue forms and grows outside the uterus due to oestrogen-induced epithelial-mesenchymal transition in the female reproductive tract. Factors that suppress this event could become potential therapeutic agents against disease occurrence and progression. However, an overview of these studies is still lacking. This review assessed the impact of a number factors on oestrogen-mediated epithelial-mesenchymal transition in the emergence of several diseases in the female reproductive tract, primarily endometriosis. The association between epithelial-mesenchymal transition and Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome was also investigated. Oestrogen, Wnt4 and epithelial-mesenchymal transition were chosen as keywords in Scopus, PubMed, and Web of Science searches performed on 28th June 2021. Study selection was refined to cancer-irrelevant, English, original articles published between years 2011-2021. The full-text assessment was carried out for topic-related articles after title and abstract screening. Included studies were summarised and assessed for their risk of bias using the Office of Health Assessment and Translation tool. In this review, 10 articles investigating oestrogen and epithelial-mesenchymal transition in the female reproductive tract were summarised and classified into two groups: seven studies under 'factor'-modulated epithelial-mesenchymal transition and three studies under 'factor'-manipulated oestrogen-induced epithelial-mesenchymal transition. The current evidence proposes that epithelial-mesenchymal transition is one of the prime causes of reproductive-related disease. This event could be mediated by distinct stimuli, specifically oestrogen and Wnt4 aberration. The results of this review suggest that oestrogen and Wnt4 participate in epithelial-mesenchymal transition in vaginal epithelial cells in MRKH syndrome, adopting from the theories of endometriosis development, which could therefore serve as a foundation for novel target treatment, specifically related to vaginal epithelialisation, to ensure better surgical outcomes.

Systems Drug Design for Muscle Invasive Bladder Cancer and Advanced Bladder Cancer by Genome-Wide Microarray Data and Deep Learning Method with Drug Design Specifications

Bladder cancer is the 10th most common cancer worldwide. Due to the lack of understanding of the oncogenic mechanisms between muscle-invasive bladder cancer (MIBC) and advanced bladder cancer (ABC) and the limitations of current treatments, novel therapeutic approaches are urgently needed. In this study, we utilized the systems biology method via genome-wide microarray data to explore the oncogenic mechanisms of MIBC and ABC to identify their respective drug targets for systems drug discovery. First, we constructed the candidate genome-wide genetic and epigenetic networks (GWGEN) through big data mining. Second, we applied the system identification and system order detection method to delete false positives in candidate GWGENs to obtain the real GWGENs of MIBC and ABC from their genome-wide microarray data. Third, we extracted the core GWGENs from the real GWGENs by selecting the significant proteins, genes and epigenetics via the principal network projection (PNP) method. Finally, we obtained the core signaling pathways from the corresponding core GWGEN through the annotations of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway to investigate the carcinogenic mechanisms of MIBC and ABC. Based on the carcinogenic mechanisms, we selected the significant drug targets NFKB1, LEF1 and MYC for MIBC, and LEF1, MYC, NOTCH1 and FOXO1 for ABC. To design molecular drug combinations for MIBC and ABC, we employed a deep neural network (DNN)-based drug-target interaction (DTI) model with drug specifications. The DNN-based DTI model was trained by drug-target interaction databases to predict the candidate drugs for MIBC and ABC, respectively. Subsequently, the drug design specifications based on regulation ability, sensitivity and toxicity were employed as filter criteria for screening the potential drug combinations of Embelin and Obatoclax for MIBC, and Obatoclax, Entinostat and Imiquimod for ABC from their candidate drugs. In conclusion, we not only investigated the oncogenic mechanisms of MIBC and ABC, but also provided promising therapeutic options for MIBC and ABC, respectively.

Plasma and Peritoneal Fluid ZEB Levels in Patients with Endometriosis and Infertility

Zinc finger E-box-binding homeobox 1 (ZEB1) and zinc finger E-box-binding homeobox 2 (ZEB2) are transcription factors that regulate epithelial−mesenchymal transformation (EMT). The aim of this study was to compare levels of ZEB1 and ZEB2 in the peritoneal fluid and plasma between patients with and without endometriosis in order to assess their utility in the diagnostic process. Plasma and peritoneal fluid samples were collected from 50 patients with and 48 without endometriosis during planned surgical procedures in eight clinical centers. Quantitative ZEB1 and ZEB2 levels analyses were performed using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). No significant differences were observed in ZEB1 levels in any of the subanalyses nor any differences regarding ZEB2 levels between patients with and without endometriosis. Plasma ZEB2 levels were significantly higher among patients with infertility compared to fertile women (16.07 ± 12.70 ng/L vs. 12.07 ± 11.92 ng/L; p < 0.04). Both ZEB1 and ZEB2 do not seem to have a significant value in the initial diagnosis of endometriosis as a single marker. The differences in ZEB2 plasma levels between patients with and without infertility indicate the possibility of EMT dysregulation in the pathogenesis of adverse fertility outcomes.

Identification of functional TF-miRNA-hub gene regulatory network associated with ovarian endometriosis

Endometriosis (EMs), one of the most common gynecological diseases, seriously affects the health and wellness of women; however, the underlying pathogenesis remains unclear. This study focused on dysregulated genes and their predicted transcription factors (TFs) and miRNAs, which may provide ideas for further mechanistic research. The microarray expression dataset GSE58178, which included six ovarian endometriosis (OE) samples and six control samples, was downloaded from the Gene Expression Omnibus (GEO) to identify differentially expressed genes (DEGs). Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to study the cellular and organism-level functions of DEGs. The protein-protein interaction (PPI) network was built and visualized using Cytoscape, and modules and hub genes were explored using various algorithms. Furthermore, we predicted miRNAs and TFs of hub genes using online databases, and constructed the TF-miRNA-hub gene network. There were 124 upregulated genes and 66 downregulated genes in EMs tissues. GO enrichment analysis showed that DEGs were concentrated in reproductive structure development and collagen-containing extracellular matrix, while KEGG pathway analysis showed that glycolysis/gluconeogenesis and central carbon metabolism in cancer require further exploration. Subsequently, HIF1A, LDHA, PGK1, TFRC, and CD9 were identified as hub genes, 22 miRNAs and 34 TFs were predicted to be upstream regulators of hub genes, and these molecules were pooled together. In addition, we found three key feedback loops in the network, MYC-miR-34a-5p-LDHA, YY1-miR-155-5p-HIF1A, and RELA-miR-93-5p-HIF1A, which may be closely related to OE development. Taken together, our study structured a TF-miRNA-hub gene network to decipher the molecular mechanism of OE, which may provide novel insights for clinical diagnosis and treatment.

The Role of Cadherin 12 (CDH12) in the Peritoneal Fluid among Patients with Endometriosis and Endometriosis-Related Infertility

Cadherin 12 (CDH 12) can play a role in the pathogenesis of endometriosis. The aim of this study was to compare the levels of cadherin 12 in the peritoneal fluid between women with and without endometriosis. This was a multicenter cross-sectional study. Eighty-two patients undergoing laparoscopic procedures were enrolled in the study. Cadherin 12 concentrations were determined using the enzyme-linked immunosorbent assay. The level of statistical significance was set at p < 0.05. No differences in cadherin 12 concentrations between patients with and without endometriosis were observed (p = 0.4). Subgroup analyses showed that CDH 12 concentrations were significantly higher in patients with infertility or primary infertility and endometriosis in comparison with patients without endometriosis and without infertility or primary infertility (p = 0.02) and also higher in patients with stage I or II endometriosis and infertility or primary infertility than in patients without endometriosis and infertility or primary infertility (p = 0.03, p = 0.048, respectively). In total, CDH 12 levels were significantly higher in patients diagnosed with infertility or primary infertility (p = 0.0092, p = 0.009, respectively) than in fertile women. Cadherin 12 can possibly play a role in the pathogenesis of infertility, both in women with and without endometriosis.

SIRT1 upregulation promotes epithelial-mesenchymal transition by inducing senescence escape in endometriosis

Endometrial epithelial cells carry distinct cancer-associated alterations that may be more susceptible to endometriosis. Mouse models have shown that overexpression of SIRT1 associated with oncogene activation contributes to the pathogenesis of endometriosis, but the underlying reason remains elusive. Here, we used integrated systems biology analysis and found that enrichment of endometrial stromal fibroblasts in endometriosis and their cellular abundance correlated negatively with epithelial cells in clinical specimens. Furthermore, endometrial epithelial cells were characterized by significant overexpression of SIRT1, which is involved in triggering the EMT switch by escaping damage or oncogene-induced induced senescence in clinical specimens and in vitro human cell line models. This observation supports that genetic and epigenetic incident favors endometrial epithelia cells escape from senescence and fuel EMT process in endometriosis, what could be overcome by downregulation of SIRT1.

Di-(2-ethylhexyl) Phthalate Triggers Proliferation, Migration, Stemness, and Epithelial-Mesenchymal Transition in Human Endometrial and Endometriotic Epithelial Cells via the Transforming Growth Factor-β/Smad Signaling Pathway

Di-(2-ethylhexyl) phthalate (DEHP) is a frequently used plasticizer that may be linked to the development of endometriosis, a common gynecological disorder with a profound impact on quality of life. Despite its prevalence, vital access to treatment has often been hampered by a lack of understanding of its pathogenesis as well as reliable disease models. Recently, epithelial–mesenchymal transition (EMT) has been suggested to have a significant role in endometriosis pathophysiology. In this study, we found that DEHP treatment enhanced proliferation, migration, and inflammatory responses, along with EMT and stemness induction in human endometrial and endometriotic cells. The selective transforming growth factor-β (TGF-β) receptor type 1/2 inhibitor LY2109761 reversed the DEHP-induced cell proliferation and migration enhancement as well as the increased expression of crucial molecules involved in inflammation, EMT, and stemness, indicating that DEHP-triggered phenomena occur via the TGF-β/Smad signaling pathway. Our study clearly defines the role of DEHP in the etiology and pathophysiological mechanisms of endometriosis and establishes an efficient disease model for endometriosis using a biomimetic 3D cell culture technique. Altogether, our data provide novel etiological and mechanistic insights into the role of DEHP in endometriosis pathogenesis, opening avenues for developing novel preventive and therapeutic strategies for endometriosis.

The role of fascin in carcinogenesis and embryo implantation

The cytoskeleton, with its actin bundling proteins, plays crucial roles in a host of cellular function, such as cancer metastasis, antigen presentation and trophoblast migration and invasion, as a result of cytoskeletal remodeling. A key player in cytoskeletal remodeling is fascin. Upregulation of fascin induces the transition of epithelial phenotypes to mesenchymal phenotypes through complex interaction with transcription factors. Fascin expression also regulates mitochondrial F-actin to promote oxidative phosphorylation (OXPHOS) in some cancer cells. Trophoblast cells, on the other hand, exhibit similar physiological functions, involving the upregulation of genes crucial for its migration and invasion. Owing to the similar tumor-like characteristics among cancer and trophoblats, we review recent studies on fascin in relation to cancer and trophoblast cell biology; and based on existing evidence, link fascin to the establishment of the maternal-fetal interface.

Pathogenesis of Endometriosis: New Insights into Prospective Therapies

Endometriosis is a female reproductive disorder characterized by growth of uterine cells and tissue in distant sites. Around 2-10% of women experience this condition during reproductive age, 35-50% of whom encounter fertility issues or pain. To date, there are no established methods for its early diagnosis and treatment, other than surgical procedures and scans. It is difficult to identify the disease at its onset, unless symptoms such as infertility and/or pain are present. Determining the mechanisms involved in its pathogenesis is vital, not only to pave the way for early identification, but also for disease management and development of less invasive but successful treatment strategies. Endometriosis is characterized by cell proliferation, propagation, evasion of immunosurveillance, and invasive metastasis. This review reports the underlying mechanisms that are individually or collectively responsible for disease establishment and evolution. Treatment of endometriosis mainly involves hormone therapies, which may be undesirable or have their own repercussions. It is therefore important to devise alternative strategies that are both effective and cause fewer side effects. Use of phytochemicals may be one of them. This review focuses on pharmacological inhibitors that can be therapeutically investigated in terms of their effects on signaling pathways and/or mechanisms involved in the pathogenesis of endometriosis.

Identifying Common Pathogenic Features in Deep Endometriotic Nodules and Uterine Adenomyosis

Increasing imaging data point to a link between deep endometriotic nodules (DENs) and uterine adenomyosis (AD). The study aimed to investigate this link at the histological level and detect potential features shared by the two diseases. We collected formalin-fixed paraffin-embedded tissue (endometrium and lesions) from women with DENs of the rectovaginal septum (n = 13), AD (n = 14), and control subjects (n = 14). Immunohistochemical analyses of CD41 and CD68 were conducted to explore the roles of platelets and macrophages, respectively. Picrosirius red staining was carried out to gather evidence of fibrosis. Vascular endothelial growth factor (VEGF) was assessed, and total numbers of CD31-positive vessels were calculated to investigate the mechanism governing angiogenesis. Double immunohistochemistry for CD31 and alpha smooth muscle actin (αSMA) was performed to discern stable vessels. Platelet aggregation was significantly decreased in both types of lesions compared to their corresponding eutopic endometrium and healthy controls. Macrophage numbers were higher in both lesions than in their corresponding endometrium and healthy subjects. Significantly higher rates of collagen accumulation were detected in DENs and AD lesions compared to their corresponding eutopic and healthy endometrium. VEGF expression was downregulated in the stromal compartment of AD lesions compared to the healthy endometrium. The total number of vessels per area was significantly higher in DENs and AD lesions than in the healthy endometrium. Rates of αSMA-surrounded vessels were decreased in DENs and AD lesions compared to their corresponding eutopic and healthy endometrium. We report common pathogenic mechanisms between DENs and AD, namely excessive macrophage accumulation, fibrosis, and irregular angiogenesis. Our results further support the notion of DENs and AD being linked at the histological level.

Epithelial-to-mesenchymal transition contributes to the downregulation of progesterone receptor expression in endometriosis lesions

Endometriosis is a common, estrogen-dependent disease, in which endometrial tissue grows in the peritoneal cavity. These lesions often express low levels of progesterone receptors (PR), which potentially play an important role in the insufficient response to progestin treatment. Here, we uncover an interconnection between the downregulated PR expression and the epithelial-to-mesenchymal transition (EMT) in endometriotic lesions. The majority of ectopic epithelial glands (93.1 %, n = 67/72) display heterogeneous states of EMT by immunohistochemistry staining. Interestingly, low PR expression associated with high N-cadherin expression, a hallmark of EMT. In order to gain mechanistic insights, we performed in vitro functional assays with the endometriotic epithelial cell lines EM'osis and 12Z. TGF-β-induced EMT, marked by elevations of CDH2 and SNAI1/2, led to a significant downregulation of PR gene expression in both cell lines. In contrast, silencing of SNAI1 in EM'osis and of SNAI1 plus SNAI2 in 12Z elevated PR gene expression significantly. We found that not only in vitro, but also in the epithelial component of endometriotic lesions strong expression of SNAI1/2 concurred with weak expression of PR. In summary, these results suggested the negative correlation association of the heterogeneous states of EMT and suppressed PR expression in endometriotic lesions. Our functional assays indicate that EMT contributes to the downregulation of PR expression via the upregulation of EMT-TFs, like SNAI1 and SNAI2, which may ultimately lead to progesterone resistance.

Molecular dysregulations underlying the pathogenesis of endometriosis

Endometriosis is a crippling disease characterized by the presence of endometrium-like tissue or scar outside the uterine cavity, commonly confined to the peritoneal and serosal surfaces of the pelvic organs. 10-15% of women in reproductive age are estimated to be affected by endometriosis. Most of these patients present with infertility and suffer from pelvic pain. The benign disease rarely progresses to malignancy. Regardless of its high prevalence, the pathogenesis of the disease is not fully understood. Treatment options for endometriosis are limited and are often based on a symptomatic approach. The unavailability of proper diagnostic approaches, fewer therapeutic options, and sparse understanding of molecular alterations are responsible for the continued disease burden. Exploring the molecular elements causing the pathogenesis of endometriosis may lead to a number of breakthroughs in the treatment of the illness, such as the discovery of new biomarkers for diagnosis and therapeutic targets that can be a guide to better prognosis and reduced recurrence. The goal of this review is to provide the reader a critical understanding of the disease by summarizing the genetic, immunological, hormonal, and epigenetic deregulations that support the molecular basis for development of endometriotic cyst, with a special focus on the study models needed to analyze these changes in the endometriotic microenvironment.

Organization of the Cytoskeleton in Ectopic Foci of the Endometrium with Rare Localization

(1) Background: Endometriosis is a common pathology of the female reproductive system, often accompanied by pain and decreased fertility. However, its pathogenesis has not been sufficiently studied regarding the role of the cytoskeleton. In this study, we describe two clinical cases involving rare localization of extragenital endometriosis (umbilicus) and compare them with genital endometriosis of different localization (ovaries and uterus), as well as eutopic endometrium obtained with separate diagnostic curettage without confirmed pathology. (2) Methods: The relative content of actin and tubulin cytoskeleton proteins was determined by Western blotting, and the expression of genes encoding these proteins was determined by RT-PCR in the obtained intraoperative biopsies. The content of 5hmC was estimated by dot blot experiments, and the methylase/demethylase and acetylase/deacetylase contents were determined. (3) Results: The obtained results indicate that the content of the actin-binding protein alpha-actinin1 significantly increased (p < 0.05) in the groups with endometriosis, and this increase was most pronounced in patients with umbilical endometriosis. In addition, both the mRNA content of the ACTN1 gene and 5hmC content increased. It can be assumed that the increase in 5hmC is associated with a decrease in the TET3 demethylase content. Moreover, in the groups with extragenital endometriosis, alpha- and beta-tubulin content was decreased (p < 0.05) compared to the control levels. (4) Conclusions: In analyzing the results, further distance of ectopic endometrial foci from the eutopic localization may be associated with an increase in the content of alpha-actinin1, probably due to an increase in the expression of its gene and an increase in migration potential. In this case, a favorable prognosis can be explained by a decrease in tubulin content and, consequently, a decrease in the rate of cell division.

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.

LINC01133 Inhibits Invasion and Promotes Proliferation in an Endometriosis Epithelial Cell Line

Endometriosis is a common gynecological disorder characterized by ectopic growth of endometrium outside the uterus and is associated with chronic pain and infertility. We investigated the role of the long intergenic noncoding RNA 01133 (LINC01133) in endometriosis, an lncRNA that has been implicated in several types of cancer. We found that LINC01133 is upregulated in ectopic endometriotic lesions. As expression appeared higher in the epithelial endometrial layer, we performed a siRNA knockdown of LINC01133 in an endometriosis epithelial cell line. Phenotypic assays indicated that LINC01133 may promote proliferation and suppress cellular migration, and affect the cytoskeleton and morphology of the cells. Gene ontology analysis of differentially expressed genes indicated that cell proliferation and migration pathways were affected in line with the observed phenotype. We validated upregulation of p21 and downregulation of Cyclin A at the protein level, which together with the quantification of the DNA content using fluorescence-activated cell sorting (FACS) analysis indicated that the observed effects on cellular proliferation may be due to changes in cell cycle. Further, we found testis-specific protein kinase 1 (TESK1) kinase upregulation corresponding with phosphorylation and inactivation of actin severing protein Cofilin, which could explain changes in the cytoskeleton and cellular migration. These results indicate that endometriosis is associated with LINC01133 upregulation, which may affect pathogenesis via the cellular proliferation and migration pathways.

Single-cell transcriptomic analysis of endometriosis provides insights into fibroblast fates and immune cell heterogeneity

Background

Endometriosis is an oestrogen-dependent disease with an unclear aetiology and pathogenesis affecting 6–10% of the global female population, predominantly those of reproductive age. Herein, we profile the transcriptomes of approximately 55,000 single cells from three groups including ectopic endometrium, eutopic endometrium from women with endometriosis, and eutopic endometrium from healthy women to create a single-cell transcriptome atlas of endometriosis.

Results

We have identified 9 cell types and performed single-cell analysis of fibroblasts, and determined a potential developmental trajectory associated with endometriosis. We also identified fibroblast subpopulations related to endometriosis development and found that StAR played an important role in this process. Moreover, T cells in endometriosis were less activated or inflammatory with decreased effector CD8 + T cells, while the composition ratio of natural killer cells decreased and the percentage of monocytes/macrophages increased in endometriosis cysts. In addition, the effectiveness of immune cells in endometriosis lesions, eutopic endometrium from women with endometriosis, and eutopic endometrium from healthy women was distinct. Cell–cell interaction analyses highlighted the imbalanced immune environment in endometriosis lesions and immune cells in endometriosis could promote the development of the disease.

Conclusion

Our study provided a systematic characterisation of endometriosis and insights into the aetiology and pathology of endometriosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00637-x.

Adenomyosis is associated with specific proton nuclear magnetic resonance (1H-NMR) serum metabolic profiles

OBJECTIVE

To determine whether the adenomyosis phenotype affects the proton nuclear magnetic resonance (¹H-NMR)-based serum metabolic profile of patients.

DESIGN

Cohort study.

SETTING

University hospital-based research center.

PATIENTS

Seventy-seven patients who underwent laparoscopy for a benign gynecologic condition.

INTERVENTIONS

Pelvic magnetic resonance imaging and collection of a venous peripheral blood sample were performed during the preoperative workup. The women were allocated to the adenomyosis group (n = 32), or the control group (n = 45). The adenomyosis group was further subdivided into two groups: diffuse adenomyosis of the inner myometrium (n = 14) and focal adenomyosis of the outer myometrium (n = 18). Other adenomyosis phenotypes were excluded.

MAIN OUTCOME MEASURES

Metabolomic profiling based on ¹H-NMR spectroscopy in combination with statistical approaches.

RESULTS

The serum metabolic profiles of the patients with adenomyosis indicated lower concentrations of 3-hydroxybutyrate, glutamate, and serine compared with controls. Conversely, the concentrations of proline, choline, citrate, 2-hydroxybutyrate, and creatinine were higher in the adenomyosis group. The focal adenomyosis of the outer myometrium and the diffuse adenomyosis phenotypes also each exhibited a specific metabolic profile.

CONCLUSION

Serum metabolic changes were detected in women with features of adenomyosis compared with their disease-free counterparts, and a number of specific metabolic pathways appear to be engaged according to the adenomyosis phenotype. The metabolites with altered levels are particularly involved in immune activation as well as cell proliferation and cell migration. Nevertheless, this study did find evidence of a correlation between metabolite levels and symptoms thought to be related to adenomyosis. Further studies are required to determine the clinical significance of these differences in metabolic profiles.

Induction of the epithelial-mesenchymal transition in the endometrium by chronic endometritis in infertile patients

Background

The purpose of the present study was to evaluate the relationship between chronic endometritis and the epithelial-mesenchymal transition in the endometrium of infertile patients in the implantation phase.

Methods

Endometrial biopsy specimens from 66 infertility patients were analyzed. The presence of chronic endometritis was investigated by immunostaining for CD138. Immunohistochemical staining for E-cadherin, N-cadherin, Slug, and Snail was performed, and the expression profiles were statistically analyzed according to the presence of chronic endometritis. When the loss of E-cadherin expression and/or the positive expression of N-cadherin was detected, the specimen was considered epithelial-mesenchymal transition-positive. Epithelial-mesenchymal transition-positive cases were also statistically analyzed according to the presence of chronic endometritis. The characteristics of the patients in the epithelial-mesenchymal transition-positive and epithelial-mesenchymal transition-negative groups were compared. The association between variables, including age, body mass index, gravidity, parity, and each causative factor of infertility and epithelial-mesenchymal transition positivity was analyzed.

Results

The rates of the loss of E-cadherin expression, the gain of N-cadherin and epithelial-mesenchymal transition positivity were significantly higher in chronic endometritis patients. The expression of Slug, cytoplasmic Snail, and nuclear Snail was also detected at significantly higher rates in chronic endometritis patients. Chronic endometritis were related to the epithelial-mesenchymal transition.

Conclusion

The epithelial-mesenchymal transition was frequently detected in the endometrium in infertile patients with chronic endometritis. Since the epithelial-mesenchymal transition is associated with chronic endometritis, the epithelial-mesenchymal transition appears to be involved in the alteration of mechanisms of implantation.

Disturbed progesterone signalling in an advanced preclinical model of endometriosis

RESEARCH QUESTION

Do human endometriosis organoids recapitulate aberrant progesterone signalling in the disease to serve as advanced experimental models for uncovering epigenetic mechanisms involved in attenuated progesterone response in endometriosis?

DESIGN

Initially, the organoids were established from acquired biopsies (women with and without endometriosis) and characterized by morphological, histological and immunostaining analyses.

RESULTS

A panel of endometriosis-related genes showed a pattern of expressions in cytochrome c oxidase subunit II (COX2), matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitor of metalloproteinase-3 (TIMP3), transforming growth factor beta 1 (TGF-β1), and zinc finger E-box binding homeobox 1 (ZEB1), and a contradictory expression pattern for cadherin (CDH1), POU class 5 homeobox 1 (POU5F1; also known as OCT4), and Nanog homeobox (NANOG) in the endometriosis organoids that is concordant with published research. These endometriosis organoids failed to upregulate 17β-Hydroxysteroid dehydrogenase 2 (17HSDβ2), progestogen associated endometrial protein (PAEP), secreted phosphoprotein 1 (SPP1), and leukaemia inhibitory factor (LIF) in response to progesterone at the level observed in control endometrium organoids. Progesterone receptor B (PRB) gene expression significantly decreased in both eutopic and ectopic organoids compared with control endometrium organoids. DNA hypermethylation, as an epigenetic mechanism for suppression of transcription, was detected at the PRB promoter in the eutopic, but not ectopic, organoids. Therefore, other epigenetic mechanisms, such as histone modifications and microRNAs, may be responsible for PRB downregulation in ectopic organoids.

CONCLUSIONS

Endometriosis organoids are powerful preclinical models that can be used to investigate the molecular mechanisms involved in endometriosis-associated progesterone resistance.

60S acidic ribosomal protein P1 (RPLP1) is elevated in human endometriotic tissue and in a murine model of endometriosis and is essential for endometriotic epithelial cell survival in vitro

Endometriosis is a female disease which is defined as the presence of ectopic endometrial tissue and is dependent on estrogen for its survival in these ectopic locations. Expression of the ribosomal protein large P1 (RPLP1) is associated with cell proliferation and invasion in several pathologies, but a role in the pathophysiology of endometriosis has not been explored. In this study, we aimed to evaluate the expression and function of RPLP1 with respect to endometriosis pathophysiology. RPLP1 protein was localised by immunohistochemistry (IHC) in eutopic and ectopic tissue from 28 subjects with confirmed endometriosis and from 20 women without signs or symptoms of the disease, while transcript levels were evaluated by qRT-PCR in 77 endometriotic lesions and 55 matched eutopic endometrial biopsies, and protein expression was evaluated using western blotting in 20 of these matched samples. To evaluate the mechanism for enhanced lesion expression of RPLP1, an experimental murine model of endometriosis was used and RPLP1 expression was localized using IHC. In vitro studies using an endometriosis cell line coupled with shRNA knockdown was used to demonstrate its role in cell survival. Expression of RPLP1 mRNA and protein were significantly higher in ectopic lesion tissue compared to paired eutopic endometrium and immunohistochemical localisation revealed predominant localisation to epithelial cells. This pattern of lesion RPLP1 was recapitulated in mice with experimentally induced endometriosis. Stable knockdown of RPLP1 protein resulted in a significant decrease in cell survival in vitro. These studies reveal that RPLP1 is associated with cell proliferation and/or survival and may play a role in the pathophysiology of endometriosis.

Effect of luteinizing hormone concentration on transcriptome and subcellular organelle phenotype of ovarian granulosa cells

RESEARCH QUESTION

Granulosa cells (GCs) surrounding oocytes are crucial for follicular growth, oocyte development, ovulation, and luteinization under the dynamic co-stimulation of follicle stimulating hormone (FSH) and luteinizing hormone (LH). This study aimed to investigate the effect of LH levels on GCs in preovulatory follicles under gonadotropin releasing hormone antagonist-based ovarian stimulation. In vitro experiments were also conducted to study the direct effect of LH on GCs.

METHODS

Twelve infertile women were divided into low (L), medium (M), and high (H) LH groups according to their serum LH levels during ovarian stimulation. RNA-sequencing (RNA-seq) was conducted to examine the transcriptome profiles of GCs obtained from the above patients during the oocyte retrieval. The activity of mitochondrial dehydrogenase was measured under the stimulation of recombinant LH (rLH) concentration gradient combined with recombinant FSH. The ultrastructures of subcellular organelles were observed.

RESULTS

Bioinformatic analyses showed that compared with the M group, molecule and pathway changes in the L group and in the H group were similar. In cultured GCs, both insufficient and excessive rLH impaired the activity of mitochondrial dehydrogenase. With the medium rLH concentration, numerous cell connections and abundant mitochondria and liposomes were observed. Compared with the medium concentration, GCs showed smaller and rounder mitochondria, more autophagosomes, and massive organelles damages with excessive rLH, and swollen, circular, or forked mitochondria were observed with inadequate rLH.

CONCLUSIONS

RNA-seq provided a novel spectrum of transcriptome characteristics of GCs potentially affected by serum LH levels during ovarian stimulation. In vitro, rLH could directly affect GCs at the subcellular level.

Recepteur d'origine nantais contributes to the development of endometriosis via promoting epithelial-mesenchymal transition of a endometrial epithelial cells

Endometriosis is a benign, chronic inflammatory disease that commonly occurs in reproductive‐aged women. Epithelial‐mesenchymal transition (EMT) of endometrial epithelial cells plays an important role in the development of endometriosis. Recepteur d'origine nantais (RON), a receptor tyrosine kinase, has been reported to promote EMT and progression in tumours. However, whether and how RON mediates the EMT and endometriosis development is not known. Here, we found that RON activation could improve the migratory and invasive capabilities, change cellular morphologies, and decrease expression of E‐cadherin and increase expression of N‐cadherin in endometrial epithelial cells. Inhibition or knockdown of RON expression suppressed the migration and invasion of endometrial epithelial cells. Our studies also indicated that RON played its part in endometrial epithelial cells through protein kinase B (Akt) and mitogen‐activated protein kinase (MAPK) pathways. Treatment with a RON inhibitor could decrease the number of ectopic lesions in a mouse model of endometriosis and mediate expression of EMT markers in endometriotic lesions. These data suggest that RON contributed to endometriosis development by promoting EMT of endometrial epithelial cells. Therefore, RON may be a new therapeutic target for endometriosis.

Tumor necrosis factor receptor type 1-associated death domain (TRADD) regulates epithelial-mesenchymal transition (EMT), M1/M2 macrophage polarization and ectopic endometrial cysts formation in endometriosis

Background

Endometriosis is a gynecological non-malignant disease that is manifested by the presence of extrauterine ectopic endometrial cells and stroma. The aim of current study was to explore the role of tumor necrosis factor receptor type 1-associated death domain (TRADD) protein in endometriosis.

Methods

Cell migration, invasion, and the expression of epithelial-mesenchymal transition (EMT) inducers in TRADD silencing or overexpression in eutopic endometrial stromal cells (EuSCs) and ectopic endometrial stromal cells (EcSCs) were analyzed by wound healing assay, transwell assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting and rat endometriosis model. A cell line derived from THP-1 macrophages was used to measure M1/M2 polarization in endometriosis by flow cytometry and enzyme-linked immunosorbent assay (ELISA).

Results

The mRNA level and protein expression of TRADD, keratin, E-cadherin, N-cadherin, vascular endothelial growth factor, matrix metalloproteinase-9, CD40, and CD206 were abnormally expressed in ectopic endometrial tissues and EcSCs. TRADD silencing promoted migration, invasion, and EMT in EuSCs, while TRADD overexpression restrained migration, invasion, and EMT in EcSCs. TRADD knockdown prohibited M1/M2 polarization in normal endometrial homogenization-treated THP-1-derived macrophages, whereas TRADD upregulation facilitated M1/M2 polarization in patients with endometrial homogenization-treated THP-1-derived macrophages. In addition, TRADD overexpression suppressed ectopic endometrial cysts formation in a rat endometriosis model. TRADD overexpression activated NF-κB and MAPK signaling in EcSCs and rat models.

Conclusions

Our results indicated that the overexpression of TRADD prohibited migration, invasion, EMT, M1/M2 polarization and ectopic endometrial cysts formation in endometriosis, and this might due to regulating NF-κB and MAPK signaling.

MTA1, a Target of Resveratrol, Promotes Epithelial-Mesenchymal Transition of Endometriosis via ZEB2

Endometriosis is a benign disease that shares some malignant features. Epithelial-mesenchymal transition (EMT) is involved in the pathogenesis of endometriosis. Metastasis-associated protein 1 (MTA1) plays an important role in various cancers by promoting EMT, yet there are no studies on its function in endometriosis. In the present study, we found that MTA1 was highly expressed in the ectopic endometrium of endometriosis patients and that the expression of MTA1 was related to the revised American Fertility Society stage. MTA1 facilitated endometrial stroma cell proliferation, migration, and invasion by inducing EMT, and the promotion function and MTA1 expression were suppressed by resveratrol, a natural polyphenol. Moreover, we revealed that MTA1 induced EMT through interaction with ZEB2. The findings in a mouse endometriosis model further showed that MTA1 and ZEB2 were upregulated in ectopic tissues and that resveratrol inhibited the growth of ectopic lesions and expression of MTA1 and ZEB2. Taken together, we demonstrate that MTA1 is a protein that promotes EMT via interacting with ZEB2 in the pathogenesis of endometriosis, and may be a target of resveratrol.

MicroRNA‑202 inhibits endometrial stromal cell migration and invasion by suppressing the K‑Ras/Raf1/MEK/ERK signaling pathway

The enhanced migratory ability of endometrial stromal cells (ESCs) is a key factor in the formation of functional endometrium‑like tissues outside the uterine cavity during endometriosis (EMS). Although accumulating evidence has suggested the importance of microRNAs (miRNAs) in the pathogenesis of EMS, the role of particular miRNAs in the invasiveness of ESCs remain poorly understood. In the present study, the function of miRNAs in the invasiveness of ESCs, along with the associated underlying mechanism involved, were investigated. Initially, the expression patterns of miRNAs in the ectopic and eutopic endometrium isolated from patients with EMS were analyzed using microarray. MicroRNA‑202‑5p (miR‑202) was selected for further study due to its previously reported suppressive effects on the invasion in various types of cancers. The expression of miR‑202 and K‑Ras in eutopic and ectopic endometrioma tissues were detected using reverse transcription‑quantitative PCR, immunohistochemistry and western blotting. The migration and invasion ability of ESCs was determined using wound healing and Transwell invasion assays, respectively. Compared with that from healthy individuals, miR‑202 expression was demonstrated to be lower in the eutopic endometrium from patients with EMS, which was even lower in ectopic endometrium. Functional experiments in primary ESCs revealed that enhanced miR‑202 expression suppressed the cell invasion and migration abilities, which was also accompanied with increased E‑cadherin and reduced N‑cadherin expression in ESCs, suggesting its potentially suppressive role in epithelial‑mesenchymal transition. K‑Ras is a well‑known regulator of the ERK signaling pathway that was shown to be directly targeted and negatively regulated by miR‑202. In addition, K‑Ras expression was found to be upregulated in the ectopic endometrium, where it correlated negatively with that of miR‑202. Knocking down K‑Ras expression mimicked the anti‑invasive effects of miR‑202 overexpression on ESCs, whilst K‑Ras overexpression attenuated the inhibitory role of miR‑202 overexpression in ESC invasion. The K‑Ras/Raf1/MEK/ERK signaling pathway was also blocked by miR‑202 overexpression. These findings suggested that miR‑202 inhibited ESC migration and invasion by inhibiting the K‑Ras/Raf1/MEK/ERK signaling pathway, rendering miR‑202 a candidate for being a therapeutic target for EMS.

Mesothelial Cells Participate in Endometriosis Fibrogenesis Through Platelet-Induced Mesothelial-Mesenchymal Transition

CONTEXT

While fibrosis in endometriosis has recently loomed prominently, the sources of myofibroblasts, the principal effector cell in fibrotic diseases, remain largely obscure. Mesothelial cells (MCs) can be converted into myofibroblasts through mesothelial-mesenchymal transition (MMT) in many fibrotic diseases and adhesion.

OBJECTIVE

To evaluate whether MCs contribute to the progression and fibrogenesis in endometriosis through MMT.

SETTING, DESIGN, PATIENTS, INTERVENTION, AND MAIN OUTCOME MEASURES

Dual immunofluorescence staining and immunohistochemistry using antibodies against calretinin, Wilms' tumor-1 (WT-1), and α-smooth muscle actin (α-SMA) were performed on lesion samples from 30 patients each with ovarian endometrioma (OE) and deep endometriosis (DE), and 30 normal endometrial (NE) tissue samples. Human pleural and peritoneal MCs were co-cultured with activated platelets or control medium with and without neutralization of transforming growth factor β1 (TGF-β1) and/or platelet-derived growth factor receptor (PDGFR) and their morphology, proliferation, and expression levels of genes and proteins known to be involved in MMT were evaluated, along with their migratory and invasive propensity, contractility, and collagen production.

RESULTS

The number of calretinin/WT-1 and α-SMA dual-positive fibroblasts in OE/DE lesions was significantly higher than NE samples. The extent of lesional fibrosis correlated positively with the lesional α-SMA staining levels. Human MCs co-cultured with activated platelets acquire a morphology suggestive of MMT, concomitant with increased proliferation, loss of calretinin expression, and marked increase in expression of mesenchymal markers. These changes coincided with functional differentiation as reflected by increased migratory and invasive capacity, contractility, and collagen production. Neutralization of TGF-β1 and PDGFR signaling abolished platelet-induced MMT in MCs.

CONCLUSIONS

MCs contribute to lesional progression and fibrosis through platelet-induced MMT.

Exosomal CLIC1 released by CLL promotes HUVECs angiogenesis by regulating ITGβ1-MAPK/ERK axis

Accumulating evidences have suggested that exosomes are closely associated with tumor progression by affecting cell-cell communication. Here, we aimed to investigate the roles and regulatory mechanism of exosomes released from chronic lymphocytic leukemia (CLL). The expression levels of genes and proteins in cells and exosomes were examined by quantitative real-time PCR and Western blotting, respectively. MEC-1 cell-derived exosomes were obtained and co-cultured with human umbilical vein endothelial cells (HUVECs), then the capabilities of cell proliferation, metastasis and angiogenesis of HUVECs were measured by CCK-8, wound healing, transwell and tube formation assay, respectively. Chloride intracellular channel 1 (CLIC1) was significantly increased in CLL patients and markedly enriched in exosomes secreted by CLL cells. Exosomal CLIC1 secreted from MEC-1 cells were successfully transferred into HUVECs and significantly promoted the phenotypes of proliferation, metastasis and angiogenesis of HUVECs. Mechanically, exosomal CLIC1 secreted from MEC-1 cells obviously activated MAPK/ERK signaling through upregulating integrin β1 (ITGβ1) expression in HUVECs. Furthermore, rescue experiments revealed that either silencing ITGβ1 or PD98059 treatment obviously reversed the regulatory effects of exosomal CLIC1 secreted from MEC-1 cells in HUVECs. In conclusion, CLL cell-derived exosomes accelerated HUVECs metastasis and angiogenesis through transferring CLIC1 to regulate ITGβ1-MAPK/ERK signaling, indicating that CLIC1 may be a therapeutic target of CLL exosomes in the tumor microenvironment.

Integrated Bioinformatics Analysis Reveals Function and Regulatory Network of miR-200b-3p in Endometriosis

Objective

MicroRNAs play vital roles in the development of endometriosis. It is reported that miR-200b-3p is downregulated in endometriosis, although its mechanisms in this disease remain still unclear. Therefore, the purpose of this study was to explore the function and potential regulatory network of miR-200b-3p in endometriosis through database analysis.

Methods

The endometriosis gene expression profiles were downloaded from the GEO database to screen differentially expressed genes (DEGs). The predicted and validated target genes of miR-200b-3p were obtained from miRWalk and miRTarBase database. Then, a comparison was performed between miR-200b-3p target genes and DEGs. GO enrichment and KEGG pathway analysis of the target genes was performed using clusterProfiler package. STRING was used to predict the protein-protein interaction among the proteins encoded by the target genes. Then, TransmiR, LncBase, StarBase, PROMO, and AnimalTFDB were employed to identify interactive transcription factors and lncRNAs of miR-200b-3p.

Results

miR-200b-3p was associated with the transcription factors DNMT1, EZH2, HNF1B, JUN, MYB, ZEB1, and ZEB2 during the pathogenesis of endometriosis. The downstream 110 target genes were involved in the biological processes of positive regulation of MAPK cascade, muscle cell proliferation, organ growth, vasculogenesis, and axon development. KEGG analysis revealed that the main pathways related to miR-200b-3p were microRNAs in cancer, PI3K-Akt signaling pathway, colorectal cancer, and tight junction. In addition, four lncRNAs such as MALAT1, NEAT1, SNHG22, and XIST interacted with miR-200b-3p and were associated with transcription factors FOXP3 and YY1.

Conclusion

The predicted target genes and molecular regulatory network of miR-200b-3p in endometriosis not only revealed its biological function but also provided a valuable guideline for further research.

Epithelial-Mesenchymal Transition in Endometriosis-When Does It Happen?

Epithelial-mesenchymal transition (EMT) is an important process of cell remodeling characterized by the gradual loss of the epithelial phenotype and progressive gain of a mesenchymal phenotype. EMT is not an all-or-nothing process, but instead a transition of epithelial to mesenchymal cells with intermediate cell states. Recently, EMT was described in endometriosis, and many EMT-specific pathways like Twist, Snail, Slug, Zinc finger E-box-binding homeobox 1/2 (ZEB1/2), E/N-cadherin, keratins, and claudins are involved. However, as pointed out in this review, a comparison of the eutopic endometrium of women with and without endometriosis yielded only subtle changes of these EMT markers. Furthermore, only very few alterations in cell-cell contacts could be found but without changes in the epithelial phenotype. This suggests only a partial EMT which is not a prerequisite for the detachment of endometrial cells and, thus, not critical for the first step(s) in the pathogenesis of endometriosis. In contrast, the majority of changes in the EMT-related marker expression were found in the ectopic endometrium, especially in the three endometriotic entities, ovarian, peritoneal, and deep infiltrating endometriosis (DIE), compared with the eutopic endometrium. In this review, we examine the most important EMT pathways described in endometriosis and propose that partial EMT might result from the interaction of endometrial implants with their surrounding microenvironment.

Transcriptome meta-analysis reveals differences of immune profile between eutopic endometrium from stage I-II and III-IV endometriosis independently of hormonal milieu

Eutopic endometrium appears to be crucial for endometriosis development. Despite of the evident importance, data regarding the cellular microenvironment remain unclear. Our objective was to explore the tissue microenvironment heterogeneity, transcripts, and pathways that are enriched in all phases of the menstrual cycle by analysing publicly deposited data derived from whole transcriptome microarrays of eutopic endometria of women with and without endometriosis. A meta-analysis of the transcriptome microarrays was performed using raw data available from a public database. Eligibility criteria included eutopic endometrium samples from women with endometriosis and healthy controls without any pathological condition reported the presence of an adequately reported normal menstrual phase, and samples containing both glandular and stromal components. Raw data were processed using a robust multiarray average method to provide background correction, normalisation, and summarisation. The batch effect was estimated by principal variant component analysis and removed using an empirical Bayes method. Cellular tissue heterogeneity was inferred using the xCell package. Differentially expressed genes were identified based on a 5% adjusted p value and a 2.0-fold change. Pathways were identified by functional enrichment based on the Molecular Signatures Database, a p value of < 5%, and an FDR q value of ≤ 25%. Genes that were more frequently found in pathways were identified using leading edge analysis. In a manner independent of cycle phase, the subpopulations of activated dendritic cells, CD4 T effector memory phenotype cells, eosinophils, macrophages M1, and natural killer T cells (NKT) were all higher in stage I-II endometriosis compared to those in healthy controls. The subpopulations of M2 macrophages and natural killer T cells were elevated in eutopic endometriums from women with stage III-IV endometriosis, and smooth muscle cells were always more prevalent in healthy eutopic endometriums. Among the differently expressed genes, FOS, FOSB, JUNB, and EGR1 were the most frequently mapped within the interaction networks, and this was independent of stage and cycle phase. The enriched pathways were directly related to immune surveillance, stem cell self-renewal, and epithelial mesenchymal transition. PI3K AKT mTOR, TGF signalling, and interferon alpha/gamma responses were enriched exclusively in stage III-IV endometriosis. The cellular microenvironments and immune cell profiles were different between eutopic endometriums from women with stage I-II and stage III-IV endometriosis, and these differences were independent of the hormonal milieu. Specifically, a pro-inflammatory profile was predominant in stage I-II endometriosis, and M1-M2 polarization into eutopic endometrium may be crucial for the progression of the disease. The higher prevalence of NKT cells in eutopic endometriums from women with endometriosis that was independent of cycle phase or staging suggested a sustained stress and/or damage to these eutopic endometriums. Based on this, the results of this meta-analysis are important for identifying challenges and opportunities for future research.

MicroRNA-126-5p downregulates BCAR3 expression to promote cell migration and invasion in endometriosis

PURPOSE

Endometriosis (EMs) is an estrogen-dependent multifactorial disease. Inhibition of estrogen in endometrial cells contributes to their failure to form lesions in ectopic sites. However, whether reducing or suppressing the inhibitory effect of estrogen results in the establishment of ectopic lesions remains unclear. The BCAR3 gene induces estrogen resistance in estrogen-dependent breast cancer cells and promotes cell migration, invasion, and epithelial-mesenchymal transition (EMT). However, the expression of BCAR3 in endometriosis and its effect on endometrial cell function and the anti-estrogen effect of endometriosis have not been reported. These issues are addressed in the present study.

METHODS

The study included 32 cases of ectopic endometrium and eutopic endometrium in patients with endometriosis and 31 cases of normal endometrium as controls. The expression of BCAR3 and microRNA (miR)-126-5p was detected by real-time PCR, immunohistochemistry, and western blotting. The effects of BCAR3 and miR-126-5p on the morphology and biological behavior of eutopic endometrial cells were verified using lentivirus overexpression and a vector knockdown model, the CCK-8 assay, Transwell experiments, and estrogen intervention experiments using primary cultures of epithelial and stromal cells.

RESULTS

The BCAR3 gene was highly expressed in ectopic endometrium and the eutopic endometrium of patients with endometriosis, and the expression level was higher in stage III-IV patients than in stage I-II patients. In vitro cell experiments showed that miR-126-5p negatively regulated the expression of BCAR3 and its effect on the migration and invasion of stromal cells. Low expression of miR-126-5p and high expression of BCAR3 promoted endometriosis stromal cell migration and invasion. Assessment of EMT in endometriosis compared with eutopic endometrium showed that the expression of vimentin was significantly increased and the expression of E-cadherin was significantly decreased in ectopic endometrium. Estrogen promoted EMT in eutopic endometrial epithelial cells and this effect was reversed by estrogen inhibitors. BCAR3 had no direct effect on EMT and did not act synergistically with estrogen on promoting EMT.

CONCLUSION

miR-126-5p negatively regulated BCAR3 expression in eutopic endometriosis, enhanced the migration and invasion of endometrial cells, and promoted the occurrence of endometriosis. BCAR3 did not induce EMT and had no synergistic effect with estrogen, but its inhibition of anti-estrogen function may provide new insight into the mechanism of local estrogen action in endometriosis.

Roles of cell migration and invasion mediated by Twist in endometriosis

AIM

To investigate the roles of cell migration and invasion mediated by Twist in endometriosis.

METHODS

The protein levels and locations of Twist, N-cadherin and E-cadherin were measured by Western blot and immunohistochemistry in ectopic endometrium and eutopic endometrium of ovarian endometriosis as well as normal endometrium of nonendometriosis patients. The messenger RNA (mRNA) expressions of Twist, N-cadherin and E-cadherin in these tissues were measured by quantitative reverse transcription polymerase chain reaction. Stable overexpression of Twist in eutopic endometrial stromal cells was transfected with a plasmid-mediated delivery system. The protein and mRNA expressions of N-cadherin and E-cadherin were detected by western blot and reverse transcription polymerase chain reaction. The changes of migration and invasion of endometrial stromal cells were explored by transwell.

RESULTS

Levels of protein and mRNA of Twist and N-cadherin showed the highest expression in ectopic endometrium of ovarian endometriosis, while lowest in normal endometrium of nonendometriosis patients. On the contrary, the expression of E-cadherin showed highest in normal endometrium of nonendometriosis patients. The overexpression of Twist after transfection significantly upregulated the protein and mRNA expression of N-cadherin, while downregulated the protein and mRNA expression of E-cadherin. There is significant difference between groups. For transwell, the overexpression of Twist in eutopic endometrial stromal cell significantly promoted cell migration and invasion.

CONCLUSION

Twist might be related with the increase of migration and invasion in endometrial stromal cells, mediated by epithelial-to-mesenchymal transition.

Enhanced expression of TACE contributes to elevated levels of sVCAM-1 in endometriosis

STUDY QUESTION

Are increased sVCAM-1 and sICAM-1 levels associated with tumor necrosis factor-alpha-converting enzyme (TACE) activity in endometriosis?

SUMMARY ANSWER

Here we provide the first functional evidence that induced TACE activity in human endometriotic epithelial cells is at least in part responsible for the enhanced release of sVCAM-1 from these cells.

WHAT IS KNOWN ALREADY

We and others have shown that serum-soluble (s)VCAM-1 levels are significantly higher in women with endometriosis, compared to disease-free controls. Experimental evidence exists suggesting a role of sICAM-1 and sVCAM-1 in the pathogenesis of endometriosis. TACE was identified as the protease responsible for phorbol 12-myristate 13-acetate (PMA)-induced VCAM-1 release in murine endothelial cells. Additionally, it has recently been shown that TACE is upregulated in the endometrial luminal epithelium of the mid-secretory phase in infertile women.

STUDY DESIGN, SIZE, DURATION

This study was conducted at the Tertiary Endometriosis Referral Center of the Medical University of Vienna. Samples from a total number of 97 women were collected between July 2013 and September 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

After complete surgical exploration of the abdominopelvic cavity, 49 women with histologically proven endometriosis and 48 endometriosis-free control women were enrolled. Each participating woman contributed only one sample of eutopic endometrium and normal peritoneum, and some of the women with endometriosis contributed samples of diverse types of endometriotic lesions (in total 52 ectopic samples). Among the 49 women with endometriosis, 36 matched samples of endometriotic lesions and corresponding eutopic endometrium were collected. In order to detect sVCAM-1 and TACE protein by ELISA, peritoneal fluid (PF) samples were collected from 44 cases and 32 controls during surgery. Expression of TACE mRNA was analyzed by qRT-PCR in 111 endometrium tissue samples (28 eutopic control samples, 33 eutopic samples from women with endometriosis, 50 ectopic samples from lesions) and 37 healthy peritoneum samples. Immunohistochemistry was performed in 123 tissue samples (39 eutopic control samples, 42 eutopic samples from women with endometriosis, 42 ectopic samples from lesions) and the relation between tissue TACE protein levels and sVCAM-1 secretion was examined. PMA-induced sVCAM-1 release, and TACE- and VCAM-1-transcripts or proteins were measured in an immortalized endometriotic epithelial cell line (11Z) pre-incubated either with TACE inhibitors or following TACE siRNA knockdown.

MAIN RESULTS AND THE ROLE OF CHANCE

Here, we demonstrate that TACE protein is overexpressed in epithelium of tissue samples of both eutopic endometrium and ectopic lesions of women with endometriosis compared to disease-free controls (P < 0.001 both) and that the overexpression of the protein in the lesions is due to activation of TACE gene transcription (P < 0.001). Moreover, epithelial TACE protein was significantly higher in ectopic samples than in corresponding eutopic tissue of women with the disease (P < 0.001). High endometrial tissue TACE protein expression correlated with higher serum sVCAM-1 levels (P < 0.05) but not with sICAM-1 levels. Inhibition of TACE either by TACE inhibitors or by TACE siRNA knockdown resulted in decreased PMA-induced shedding of sVCAM-1 in vitro (P < 0.005 or P < 0.01, respectively), but the TACE inhibitors did not affect transcription of TACE or VCAM-1. Additionally, we observed an upregulation of TACE in proliferative endometrial epithelium of infertile (P < 0.005), compared to fertile women. TACE was increased in infertile women with endometriosis (P = 0.051) but not in infertile women without endometriosis.

LIMITATIONS, REASONS FOR CAUTION

Albeit well characterized, our control population included women with other gynecologic diseases, which may have impacted the levels of sVCAM-1 and tissue TACE expression levels, e.g. benign ovarian cysts or uterine fibroids. Thus, the results of our analysis have to be interpreted carefully and in the context of the current experimental settings.

WIDER IMPLICATIONS OF THE FINDINGS

The dysregulation of TACE substrate shedding represents a promising yet relatively unexplored area of endometriosis progression and could serve as a basis for the development of new treatments of the disease.

STUDY FUNDING AND COMPETING INTEREST(S)

This work was supported by the Ingrid Flick Foundation. The authors have no competing interests to declare.

Estradiol promotes EMT in endometriosis via MALAT1/miR200s sponge function

Endometriosis is an estrogen-dependent benign gynecological disease that shares some common features of malignancy. Epithelial-mesenchymal transition (EMT) has been recognized as a core mechanism of endometriosis. MALAT1 is widely known as EMT promoter, while miR200 family members (miR200s) are considered as EMT inhibitors. Previous studies have reported that MALAT1 upregulation and miR200s downregulation are observed in endometriosis. MiR200c has been regarded as the strongest member of miR200s to interact with MALAT1. However, whether MALAT1/miR200c regulates EMT remains largely unclear. In this study, the roles of miR200s and MALAT1 in ectopic endometrium were investigated. Additionally, the effects of E2 on EMT and MALAT1/miR200s were examined in both EECs and Ishikawa cells. Notably, E2 could upregulate MALAT1 and downregulate miR200s expression levels and induce EMT in EECs and Ishikawa cells. PHTPP, an ERβ antagonist, could reverse the effect of E2. Overexpression of miR200c and knockdown of MALAT1 significantly inhibited E2-mediated EMT, suggesting that both miR200c and MALAT1 are involved in the E2-induced EMT process in endometriosis. In addition, a reciprocal inhibition was found between miR200s and MALAT1. Therefore, the role of MALAT1/miR200c in EMT is influenced by the presence of estrogen during endometriosis development.

ILK enhances migration and invasion abilities of human endometrial stromal cells by facilitating the epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) plays a significant part in the pathogenesis of endometriosis by facilitating the migration and invasion abilities of cells. Integrin-linked kinase (ILK) increases the cell migration and invasion abilities by inducing the EMT. Eutopic and control endometrial stromal cells (EuSCs and CSCs) were isolated and cultured. Cell migration and invasion abilities were detected by transwell assays. Levels of proteins were detected by Western blot. EuSCs showed higher levels of ILK, N-cadherin, vimentin and stronger migration and invasion abilities. After transfection of siRNA-ILK, E-cadherin and keratin levels were increased while N-cadherin and vimentin levels were decreased in EuSCs. Besides that, the migration and invasion abilities of EuSCs were significantly decreased after transfection of siRNA-ILK. On the contrary, levels of ILK, N-cadherin and vimentin were increased while levels of E-cadherin and keratin were decreased simultaneously after transfecting CSCs with pEGFP-C1-ILK. Simultaneously, the migration and invasion abilities of CSCs were increased after transfection of pEGFP-C1-ILK. Our study verified that high expression of ILK enhanced the migration and invasion abilities of ESCs by facilitating the EMT. Given that ILK played crucial roles in the pathogenesis of endometriosis, it may be considered as a promising targeted therapy for endometriosis.

Cancer driver mutations in endometriosis: Variations on the major theme of fibrogenesis

BACKGROUND

One recent study reports cancer driver mutations in deep endometriosis, but its biological/clinical significance remains unclear. Since the natural history of endometriosis is essentially gradual progression toward fibrosis, it is thus hypothesized that the six driver genes reported to be mutated in endometriosis (the RP set) may play important roles in fibrogenesis but not necessarily malignant transformation.

METHODS

Extensive PubMed search to see whether RP and another set of driver genes not yet reported (NR) to be mutated in endometriosis have any roles in fibrogenesis. All studies reporting on the role of fibrogenesis of the genes in both RP and NR sets were retrieved and evaluated in this review.

RESULTS

All six RP genes were involved in various aspects of fibrogenesis as compared with only three NR genes. These nine genes can be anchored in networks linking with their upstream and downstream genes that are known to be aberrantly expressed in endometriosis, piecing together seemingly unrelated findings.

CONCLUSIONS

Given that somatic driver mutations can and do occur frequently in physiologically normal tissues, it is argued that these mutations in endometriosis are not necessarily synonymous with malignancy or premalignancy, but the result of enormous pressure for fibrogenesis.

Direct Cell⁻Cell Interactions in the Endometrium and in Endometrial Pathophysiology

Cell contacts exhibit a considerable influence on tissue physiology and homeostasis by controlling paracellular and intercellular transport processes, as well as by affecting signaling pathways. Since they maintain cell polarity, they play an important role in cell plasticity. The knowledge about the junctional protein families and their interactions has increased considerably during recent years. In contrast to most other tissues, the endometrium undergoes extensive physiological changes and reveals an extraordinary plasticity due to its crucial role in the establishment and maintenance of pregnancy. These complex changes are accompanied by changes in direct cell–cell contacts to meet the various requirements in the respective developmental stage. Impairment of this sophisticated differentiation process may lead to failure of implantation and embryo development and may be involved in the pathogenesis of endometrial diseases. In this article, we focus on the knowledge about the distribution and regulation of the different junctional proteins in the endometrium during cycling and pregnancy, as well as in pathologic conditions such as endometriosis and cancer. Decoding these sophisticated interactions should improve our understanding of endometrial physiology as well as of the mechanisms involved in pathological conditions.