ZEB1 expression is a potential indicator of invasive endometriosis

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

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

How Can Selected Dietary Ingredients Influence the Development and Progression of Endometriosis?

Endometriosis is a chronic, hormone-dependent disease characterized by the presence of endometrial tissue in ectopic locations. Since the treatment options for this disease are still limited, and the cure rate is unsatisfactory, the search for ways to treat symptoms and modify the course of the disease is of key importance in improving the quality of life of patients with endometriosis. So far, the literature has shown that nutrition can influence endometriosis through hormonal modification and altering the inflammatory or oxidative response. Since the importance of nutrition in this disease is still a subject of scientific research, we aimed to summarize the current knowledge on the role of dietary modifications in endometriosis. Our review showed that nutrients with anti-inflammatory and antioxidant properties, including most vitamins and several trace elements, may influence the pathogenesis of endometriosis and can be considered as the nutrients preventing the development of endometriosis. However, despite the many discoveries described in this review, further interdisciplinary research on this topic seems to be extremely important, as in the future, it may result in the development of personalized therapies supporting the treatment of endometriosis.

Digestive system deep infiltrating endometriosis: What do we know

Digestive system infiltrating endometriosis (DSIE) is an uncommon form of endometriosis in the digestive system. DSIE often occurs in the intestines (especially the sigmoid rectum), liver, gallbladder and pancreas. Clinically, DSIE presents with the same symptoms as endometriosis, including cyclic pain, bleeding and infertility, in addition to specific biliary/intestinal obstruction and gastrointestinal bleeding. Compared to general endometriosis, DSIE has unique biological behaviour and pathophysiological mechanisms. Most DSIEs are deep invasive endometrioses, characterized by metastasis to the lymph nodes and lymphatic vessels, angiogenesis, peripheral nerve recruitment, fibrosis and invasion of surrounding tissues. DSIE-related peripheral angiogenesis is divided into three patterns: angiogenesis, vasculogenesis and inosculation. These patterns are regulated by interactions between multiple hypoxia-hormone cytokines. The nerve growth factors regulate the extensive neurofibril recruitment in DSIE lesions, which accounts for severe symptoms of deep pain. They are also associated with fibrosis and the aggressiveness of DSIE. Cyclic changes in DSIE lesions, recurrent inflammation and oxidative stress promote repeated tissue injury and repair (ReTIAR) mechanisms in the lesions, accelerating fibril formation and cancer-related mutations. Similar to malignant tumours, DSIE can also exhibit aggressiveness derived from collective cell migration mediated by E-cadherin and N-cadherin. This often makes DSIE misdiagnosed as a malignant tumour of the digestive system in clinical practice. In addition to surgery, novel treatments are urgently required to effectively eradicate this lesion.

Detection of zeb1 Gene in Granulosa Cells in Women Undergoing IVF Treatment

BACKGROUND

ZEB1 plays a role in epithelial-to-mesenchymal transition and acts as a repressor of E-cadherin, TGF-β, and Wnt/β-catenin. Since ZEB1 protein is expressed in estrogen-responsive tissues, and expression of the gene in the normal ovary and endometrium is positively correlated with high estrogen levels, we performed a direct analysis of granulosa cell samples to determine whether there are any significant changes in zeb1 expression during folliculogenesis.

METHODS

ZEB1 expression levels were measured in the granulosa cells of 56 infertile women undergoing IVF treatment. RNA extraction from granulosa cells was performed along with reverse transcription quantitative polymerase chain reaction (RT-qPCR) with SYBR Green I to determine zeb1 gene expression levels. Statistical analysis was performed by using t-test, while possible correlations of the expression of ZEB1 protein with body mass index (BMI), age, number of oocytes, and oocyte maturation were investigated.

RESULTS

Zeb1 gene expression levels correlate significantly with body mass index (BMI) and age, but not with oocyte number and oocyte maturation stage. Obese women demonstrate a higher expression level of zeb1 gene compared to normal and overweight women. Moreover, zeb1 gene is overexpressed in women aged 35-40 years old and is under-expressed in women >40 years old.

CONCLUSIONS

ZEB1 expression should be further investigated as it may unveil new potential findings of the zeb1 gene's role in female fertility and its use as a biomarker in fertility workups.

Expression of ZEB1 in different forms of endometriosis: A pilot study

OBJECTIVES

Epithelial-Mesenchymal Transition (EMT), a cellular process in which epithelial cells lose epithelial characteristics while acquire mesenchymal features, is believed to contribute to migration and invasion abilities of the endometriotic cells. Studies on gene expression of the transcription factor ZEB1, a crucial transcription factor of EMT, show that there is probably a modified expression in the endometriotic lesions. The aim of the study was to compare the expression levels of ZEB1 in types of endometriotic lesions with different biological behavior such as endometriomas and deep infiltrating endometriotic nodules.

STUDY DESIGN

We have studied 19 patients with endometriosis and 8 patients with benign gynecological lesions without endometriosis. The endometriosis patient group included 9 women with only endometriotic cysts without deep infiltrating endometriotic lesion (DIE) and 10 women with DIE who had developed concurrent endometriotic cysts. The technique applied to investigate ZEB1 expression levels is Real-Time PCR. The results of the reaction were normalized by simultaneously investigating the expression of the house-keeping gene G6PD.

RESULTS

Analysis of the samples showed underexpression of ZEB1 in the eutopic endometrium of women with only endometriotic cysts when compared to normal endometrium. A tendency of higher ZEB1 expression, without reaching significant difference, was found between the endometriotic cysts and their paired eutopic endometrium. In women with DIE, no significant difference was found between their eutopic and normal endometrium. No significant difference was found between the endometriomas and DIE lesions. ZEB1 shows different expression profile in the endometriotic cysts of women with and without DIE when the cyst is compared to their paired eutopic endometrium.

CONCLUSIONS

It therefore appears that ZEB1 expression differs between different types of endometriosis. The expression levels of ZEB1 in the eutopic endometrium could affect the development of infiltrating lesions or not. However, the most important observation is the different ZEB1 expression profile of endometriomas between women with and without DIE. Although, they both share the same histologic characteristics, they show different ZEB1 expression indicating different pathogenetic mechanisms of endometriomas in cases with and without DIE. Therefore, future research on endometriosis should consider DIE and ovarian endometriosis as different diseases.

circPLOD2 knockdown suppresses endometriosis progression via the miR-216a-5p/ZEB1 axis

The present study aimed to identify the role of circPLOD2 in endometriosis and its underlying mechanisms. We determined circPLOD2 and miR-216a-5p expression in ectopic endometrial (EC) and eutopic endometrial (EU) samples as well as in endometrial samples from uterine fibroids of ectopic patients (EN) and embryonic stem cells (ESCs) using qRT-PCR. The association between circPLOD2 and miR-216a-5p or miR-216a-5p and zinc finger E-box binding homeobox 1 (ZEB1) expression was analyzed using Starbase, TargetScan, and dual-luciferase reporter gene assays. Cell viability, apoptosis, and migration and invasion were assessed using MTT, flow cytometry, and transwell assays, respectively. In addition, qRT-PCR and western blotting was used to measure circPLOD2, miR-216a-5p, E-cadherin, N-cadherin, and ZEB1 expression. circPLOD2 was upregulated and miR-216a-5p was downregulated in EC samples compared with that in EU samples. Similar trends were observed in ESCs. circPLOD2 interacted and negatively regulated miR-216a-5p expression in EC-ESCs. circPLOD2-siRNA significantly inhibited EC-ESC growth; promoted cellular apoptosis; and inhibited EC-ESC migration, invasion, and epithelial-mesenchymal transition; these effects could be reversed following miR-216a-5p inhibitor transfection. miR-216a-5p directly targeted and negatively regulated ZEB1 expression in EC-ESCs. In conclusion, circPLOD2 promotes the proliferation, migration, and invasion of EC-ESCs and inhibits their apoptosis by targeting miR-216a-5p. These findings indicate potential therapeutic targets for endometriosis.

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.

Inflammatory Cytokine-Induced HIF-1 Activation Promotes Epithelial-Mesenchymal Transition in Endometrial Epithelial Cells

The endometrium undergoes repeated proliferation and shedding during the menstrual cycle. Significant changes to this environment include fluctuations in the partial pressure of oxygen, exposure to a high-cytokine environment associated with intrauterine infection, and inflammation. Chronic endometritis is a condition wherein mild inflammation persists in the endometrium and is one of the causes of implantation failure and miscarriage in early pregnancy. It is thought that the invasion of embryos into the endometrium requires epithelial-mesenchymal transition (EMT)-associated changes in the endometrial epithelium. However, the effects of inflammation on the endometrium remain poorly understood. In this study, we investigated the effects of the intrauterine oxygen environment, hypoxia-inducible factor (HIF), and inflammation on the differentiation and function of endometrial epithelial cells. We elucidated the ways in which inflammatory cytokines affect HIF activity and EMT in an immortalized cell line (EM-E6/E7/TERT) derived from endometrial epithelium. Pro-inflammatory cytokines caused significant accumulation of HIF-1α protein, increased HIF-1α mRNA levels, and enhanced hypoxia-induced accumulation of HIF-1α protein. The combined effect of inflammatory cytokines and hypoxia increased the expression of EMT-inducing factors and upregulated cell migration. Our findings indicate that pro-inflammatory factors, including cytokines and LPS, work synergistically with hypoxia to activate HIF-1 and promote EMT in endometrial epithelial cells.

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.

T-Cadherin, E-Cadherin, PR-A, and ER-α Levels in Deep Infiltrating Endometriosis

The goal of this study was to compare the T-cadherin, E-cadherin, progesterone receptor (PR), and estrogen receptor (ER) staining levels of deep infiltrating endometriosis (DIE) tissue, ovarian endometriomas and normal endometrial tissues in the same individuals. The tissue sections of both DIE nodule(s) and endometrioma(s) of 15 cases were examined. As a control group, normal endometrial tissue sections of 23 cases were examined. T-cadherin, E-cadherin, ER-α, and PR-A staining levels of DIE, endometrioma tissues, and endometrial tissues were compared immunohistochemically. H -score was calculated to compare the expression of T-cadherin, E-cadherin, ER-α, and PR-A in immunohistochemical staining based on the percentage of cells stained at each intensity level. T-cadherin, E-cadherin, ER, and PR H -score were lowest in DIE tissue and highest in endometrial tissue ( P <0.0001, <0.0001, <0.0001, and <0.0001, respectively). In correlation analysis, a positive correlation was found between T-cadherin, E-cadherin, PR, and ER H -score ( P <0.0001 for each). T-cadherin, E-cadherin, ER, and PR H -score were lowest in DIE tissue and highest in endometrium tissue. We think that examination of DIE tissue and endometrioma tissue from the same individual excludes the possibility of an effect due to different genetic and environmental factors from different individuals. With the help of this exclusion we showed that DIE and endometrioma have different biological properties.

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.

The Role of Mesothelin Expression in Serous Ovarian Carcinoma: Impacts on Diagnosis, Prognosis, and Therapeutic Targets

Mesothelin (MSLN) is a protein expressed in the mesothelial cell lining of the pleura, peritoneum, and pericardium; its biological functions in normal cells are still unknown. Experimental studies using knockout mice have suggested that this molecule does not play an important role in development and reproduction. In contrast, it has been observed that this molecule is produced in abnormal amounts in several malignant neoplasms, such as mesotheliomas and pancreatic adenocarcinomas. Many molecular studies have also demonstrated that mesothelin is overexpressed in HSOCs. Here, we discuss the current knowledge of mesothelin and focus on its role in clinical and pathological diagnoses, as well as its impact on the prognosis of HSOC. Moreover, regarding the binding of MSLN to the ovarian cancer antigen CA125, which has been demonstrated in many studies, we also report on signal transduction pathways that may play an important role in the spread and neoplastic progression of this lethal neoplasm. Given that mesothelin is overexpressed in many solid tumours and has antigenic properties, this molecule could be considered an antigenic target for the treatment of many malignancies. Consequently, we also review the literature to report on mesothelin-targeting therapies for HSOC that have been recently investigated in many clinical studies.

Role of the Immunohistochemical ZEB1 Expression in Uterine Mesenchymal Neoplasms

The distinction of mesenchymal tumors of the uterus is a frequent diagnostic challenge in gynecologic pathology. Especially, distinguishing low-grade endometrial stromal sarcoma (ESS) from leiomyoma or distinguishing low-grade ESS from high-grade ESS can be difficult. Epithelial-mesenchymal transition (EMT) is a physiological and pathological process in which epithelial cells lose their morphological features, become elongated and acquire mesenchymal traits. The signaling pathway of Zinc finger E-box binding homeobox 1 (ZEB1) is one of the most significant pathways involved in the EMT process and it has a crucial role in cancer progression, metastasis, and therapy resistance. We studied a series of 69 uterine mesenchymal neoplasms including 18 endometrial stromal sarcomas (10 cases of low grade and 8 cases of high grade endometrial stromal sarcomas), 26 leiomyosarcomas (8 cases of grade 1 and 19 cases of grade 2-3 leiomyosarcomas), 15 leiomyomas, and 10 rhabdomyosarcomas, using an antibody ZEB1. We graded the leiomyosarcomas depending on the FNCLCC grading system. It was observed that leiomyosarcoma was more intensely stained with ZEB1 than leiomyoma (P < 0.001) and high-grade ESS was significantly more intensely stained with ZEB1 protein than low-grade ESS (P < 0.004). It also was observed that high-grade leiomyosarcoma was significantly more intensely stained with ZEB1 protein than low-grade leiomyosarcoma (P < 0.000). Our data suggest that Zeb1 can be used to differentiate high-grade sarcomas from their low-grade counterparts as well as benign and malignant smooth muscle tumors of the uterus.

Immune micro-environment and drug analysis of peritoneal endometriosis based on epithelial-mesenchymal transition classification

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a complex event that drives polar epithelial cells transform from adherent cells to motile mesenchymal cells, in which are involved immune cells and stroma cells. EMT plays crucial roles in migration and invasion of endometriosis. The interaction of endometrial implants with the surrounding peritoneal micro-environment probably affects the development of peritoneal endometriosis. To date, very few studies have been carried out on peritoneal endometriosis sub-type classification and micro-environment analysis based on EMT. The purpose of this study is to investigate the potential application of EMT-based classification in precise diagnosis and treatment of peritoneal endometriosis.

METHOD

Based on EMT hallmark genes, 76 peritoneal endometriosis samples were classified into two clusters by consistent cluster classification. EMT scores, which calculated by Z score of 8 epithelial cell marker genes and 8 mesenchymal cell marker genes, were compared in two clusters. Then, immune scores and the abundances of corresponding immune cells, stroma scores and the abundances of corresponding stroma cells were analyzed by the "xCell" package. Futhermore, a diagnostic model was constructed based on 9 diagnostic markers which related to immune score and stroma score by Lasso-Logistic regression analysis. Finally, based on EMT classification, a total of 8 targeted drugs against two clusters were screened out by drug susceptibility analysis via "pRRophetic" package.

RESULTS

Hallmark epithelial-mesenchymal transition was the mainly enriched pathway of differentially expressed genes between peritoneal endometriosis tissues and endometrium tissues. Compared with cluster 2, EMT score and the abundances of most infiltrating stroma cell were significantly higher, while the abundances of most infiltrating immune cells were dramatically less. The diagnostic model could accurately distinguish cluster 1 from cluster 2. Pathway analysis showed drug candidates targeting cluster 1 mainly act on the IGF-1 signaling pathway, and drug candidates targeting cluster 2 mainly block the EGFR signaling pathway.

CONCLUSION

In peritoneal endometriosis, EMT was probably promoted by stroma cell infiltration and inhibited by immune cell infiltration. Besides, our study highlighted the potential uses of the EMT classification in the precise diagnosis and treatment of peritoneal endometriosis.

SKP2 regulates ZEB1 expression and stimulates eutopic endometrial stromal cell invasion and proliferation of adenomyosis

Though endometriosis is benign, however, it shares certain characteristics with cancers, such as the ability to invade and metastasize. Previous studies have demonstrated that S-phase kinase associated protein2 (SKP2) promotes invasion, tumorigenesis, and metastasis. However, its correlation with adenomyosis is unclear. Herein, we aimed to look into SKP2 expression patterns and regulatory effects on endometrial stromal cell (ESC) proliferation and invasion, and its internal mechanism in adenomyosis. Western blot, qRT-PCR, and immunochemistry were carried out for detecting SKP2 and ZEB1 expression in ESC of adenomyosis and adenomyosis endometrial tissue. The primary ESCs were identified using immunofluorescence. SKP2 knockdown was accomplished in vitro by transfecting a particular lentivirus vector. The colony formation and CCK-8 assays were carried out for assessing cell proliferation, while cell invasion potential was assessed using the transwell assay. Both SKP2 and ZEB1 were found to be significantly upregulated in adenomyosis endometrial tissue. Knockdown of SKP2 inhibited adenomyotic ESC invasion and proliferation. Further experiments showed that knocking out SKP2 reduced ZEB1 expression in adenomyotic ESCs. Our results showed that SKP2 could regulate ZEB1 expression, and increased SKP2 may play a role in the pathogenesis of adenomyosis and stimulating ESC proliferation and invasion.

The deep infiltrating endometriosis tissue has lower T-cadherin, E-cadherin, progesterone receptor and oestrogen receptor than endometrioma tissue

OBJECTIVE

To compare the T-cadherin, E-cadherin, PR and ER staining levels of deep infiltrating endometriosis (DIE) tissue, ovarian endometriomas and normal endometrial tissues.

MATERIALS AND METHODS

DIE tissue of 24 cases, endometrioma of 30 cases and normal endometrial tissues of 30 cases were examined. T-cadherin, E-cadherin, ER-α and PR-α staining levels of DIE, endometrioma tissues and endometrial tissues were compared immunohistochemically. H-score was calculated to compare the expression of T-cadherin, E-cadherin, ER-α, PR-α in IHC staining based on the percentage of cells stained at each intensity level.

RESULTS

T-cadherin, E-cadherin, ER and PR H-score were found lowest in DIE tissue and the highest in endometrial tissue (p < 0.0001, <0.0001, <0.0001 and < 0.0001, respectively). In correlation analysis, a positive correlation was found between T-cadherin, E-cadherin, PR and ER H-score (p < 0.0001 for each). No correlation was found between age, body mass index (BMI), visual analog scale (VAS) score, CA125, endometrioma size and the severity of dysmenorrhea, dyspareunia and dystonia (p > 0.05).

CONCLUSION

T-cadherin, E-cadherin, ER and PR H-score were found lowest in DIE tissue, the highest in endometrium tissue. The finding of lower expression of PR-α in endometriotic nodule in our study may be related to decrease in progesterone effect which could not inhibit the decrease in the expression of T-cadherin and E-cadherin, thus the invasiveness of DIE tissue. These findings suggest that DIE tissue and ovarian endometrioma tissues have a different biology.

Exploring Epithelial-Mesenchymal Transition Signals in Endometriosis Diagnosis and In Vitro Fertilization Outcomes

Endometriosis (EMS) pathogenesis has been related to the release of inflammatory mediators in peritoneal fluid, creating an altered microenvironment that leads to low-grade oocyte/embryos and to the reduction of implantation rates. The Epithelial–Mesenchymal Transition (EMT), an inflammation-related process, can be a further contributing factor to EMS. This study aimed to investigate, among various cytokines and EMT markers (Cadherins, TGF-β, HIF-1α), diagnostic markers of EMS and prognostic factors of in vitro fertilization (IVF) outcomes. Herein, EMS patients manifested higher serum levels of the inflammatory molecules IL-6, IL-8, and IL-12 and a decrease in the concentrations of the anti-inflammatory IL-10. Moreover, biochemical markers associated with the EMT process were more elevated in serum and follicular fluid (FF) of EMS patients than in controls. At the end, the number of good-quality embryos was inversely related to serum IL-6 and EMT markers. Interestingly, serum IL-6 and FF IL-10 concentrations differentiated EMS patients from controls. Finally, serum IL-8 and E-Cadherin levels, as well as FF IL-10, predicted positive IVF outcome with great accuracy. Our data confirm the pivotal role of inflammatory mediators (i.e., IL-6 and IL-10) in EMS pathogenesis and suggest that EMT-related markers are elevated in EMS patients and can be predictive of IVF outcome.

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.

Circular RNA circZFPM2 promotes epithelial-mesenchymal transition in endometriosis by regulating miR-205-5p/ZEB1 signalling pathway

Endometriosis is a debilitating gynecological disease affecting millions of women worldwide, but its exact pathogenesis remains unclear. Circular RNAs (circRNAs) have been demonstrated to be important regulators in multiple diseases. Nonetheless, the potential regulatory mechanism of aberrant circRNA expression in endometriosis has been elusive. The up-regulated circZFPM2 in ectopic endometrial tissues was previously screened by circRNA high-throughput sequencing and was furtherly validated by quantitative real time reverse transcriptase polymerase chain reaction (RT-qPCR). Overexpression of circZFPM2 promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in Ishikawa and End1/E6E7 cells, whereas silencing circZFPM2 produced the opposite effect. Luciferase reporter assays validated that circZFPM2 could directly target miR-205-5p and miR-205-5p target ZEB1. RT-qPCR results showed that miR-205-5p was underexpressed while ZEB1 was overexpressed in ectopic endometrial tissues compared with their expression in eutopic endometria and non-endometriosis control endometria. The expression level of miR-205-5p was inversely proportional and that of ZEB1 was directly proportional with the proliferative, migrative, and invasive ability of endometrial cells. Further in vitro investigation indicated that miR-205-5p could inhibit EMT by targeting ZEB1. Subsequent rescue experiments confirmed that circZFPM2 could induce EMT and promote cell proliferation, migration, and invasion cascades through the miR-205-5p /ZEB1 signaling pathway. Conclusively, circZFPM2 may present a promising biomarker in the diagnosis and treatment of endometriosis.

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.

MiR-370-3p inhibits the development of human endometriosis by downregulating EDN1 expression in endometrial stromal cells

MiR-370-3p has been demonstrated to be downregulated in patients with endometriosis (EM). However, its role and molecular mechanisms in the progression of EM remain unclear. Real-time polymerase chain reaction was used to measure the expression of miR-370-3p and endothelin-1 (EDN1) in patients with or without EM. After miR-370-3p overexpression or knockdown in ectopic endometrial hEM15A cells, the changes in the proliferation, apoptosis, and migration and invasion capacities were detected by using cell counting kit-8, flow cytometry, and transwell methods. The interplay between miR-370-3p and EDN1 was confirmed by a luciferase reporter assay. Patients with EM showed adverse expression of EDN1 and miR-370-3p, especially in eutopic endometrium and ectopic endometrium. MiR-370-3p inhibited the proliferation, metastasis, and invasion capacities of hEM15A cells and promoted apoptosis. Investigation of its molecular mechanism revealed that miR-370-3p targeted EDN1 to influence the biological functions of hEM15A cells. MiR-370-3p represented as a therapeutic target for EM treatment.

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.

Neuroprotective potential of fisetin in an experimental model of spinal cord injury: via modulation of NF-κB/IκBα pathway

AIM

To evaluate neuroprotective efficacy of fisetin against the experimental model of spinal cord injury (SCI).

MATERIALS AND METHODS

SCI was induced in male Sprague-Dawley rats by placing an aneurysm clip extradurally. Rats were treated either with vehicle or fisetin for 28 days after SCI.

RESULTS

Treatment with fisetin significantly attenuated SCI-induced alternations in mechano-tactile and thermal allodynia, hyperalgesia and nerve conduction velocities. SCI-induced upregulated tumor necrosis factor-alpha, interleukins, inducible nitric oxide synthase, cyclooxygenase-II, Bcl-2-associated X protein and caspase-3 mRNA expressions in the spinal cord and these were markedly reduced by fisetin. Spinal nuclear factor kappa B and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha protein levels were also significantly downregulated by fisetin. Hematoxylin and eosin staining of spinal cord suggested that fisetin significantly ameliorated histological aberrations such as neuronal degeneration, necrosis and inflammatory infiltration induced in it.

CONCLUSION

Fisetin exerts neuroprotection via modulation of nuclear factor kappa B/nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha pathway by inhibiting release of inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-II), proinflammatory cytokines (tumor necrosis factor-alpha and interleukins), apoptotic mediators (Bcl-2-associated X protein and caspase-3).

ZEB1: New advances in fibrosis and cancer

Zinc finger E-box binding homeobox 1 (ZEB1) is an important transcription factor in epithelial mesenchymal transition (EMT) which participates in the numerous life processes, such as embryonic development, fibrosis and tumor progression. ZEB1 has multiple functions in human body and plays a crucial part in some life processes. ZEB1 is vital for the formation and development of the organs in the embryonic period. The abnormal expression of ZEB1 is a predictor for the poor prognosis or the poor survival in several cancers. ZEB1 contributes to the occurrence of fibrosis, cancer and even chemoresistance. Some research is indicated that fibrosis is finally developed into the cancers. Therefore, ZEB1 is probably taken as a biomarker in fibrosis or cancer. In this review, it is predicted of the structure of ZEB1 and the protein binding sites of ZEB1 with some protein, and it is discussed about the roles of ZEB1 in fibrosis and cancer progression to elaborate the potential applications of ZEB1 in clinic.

CircATRNL1 promotes epithelial-mesenchymal transition in endometriosis by upregulating Yes-associated protein 1 in vitro

Endometriosis is a common and benign gynecological disorder but exhibits malignant features. However, the underlying pathogenesis and pathophysiology of endometriosis remain unclear. Circular RNAs have been demonstrated to participate in the occurrence and progression of multiple diseases. This study was aimed to explore the roles of circATRNL1 in endometriosis in vitro. Based on the results of reverse transcription-quantitative polymerase chain reaction analysis, we found significant upregulation of circATRNL1 and Yes-associated protein 1 (YAP1), while downregulation of miR-141-3p and miR-200a-3p in ectopic tissues compared to eutopic tissues. The immunohistochemistry and western blot analysis showed differentially expressed epithelial-mesenchymal transition (EMT) markers between EuEM and EcEM tissues. The in vitro assays indicated that overexpression of circATRNL1 could promote the proliferation, migration, and invasion of Ishikawa cells, and induce EMT process, while circATRNL1 silencing showed the opposite effect. The mechanical investigation indicated that circATRNL1 upregulated YAP1 by sponging miR-141-3p and miR-200a-3p. Gain-of-function assays validated the inhibitory function of miR-141-3p and miR-200a-3p in endometriosis. The results of rescue assays confirmed the function of circATRNL1-miR-141-3p/miR-200a-3p-YAP1 axis on Ishikawa cells. Our findings demonstrate that abnormal upregulation of circATRNL1 regulates cell proliferation and motility and promotes EMT process via the miR-141-3p/miR-200a-3p-YAP1 axis in vitro, which could contribute to the progression of endometriosis.

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.

Mucin gene polymorphisms are associated with endometriosis in Korean women

OBJECTIVE

Mucin family members mucin 1 (MUC1) and mucin 4 (MUC4) play an important role in transformation and adhesion, and are known markers for the detection of cancer. However, the pathophysiology of endometriosis associated with the mucin gene is unclear. In this study, we analyzed the relationship between MUC1 and MUC4 single-nucleotide polymorphisms (SNPs) and the risk for endometriosis.

METHODS

We performed a case-controlled study of 29 endometriosis clinical samples and 27 functional cysts as control. Sixteen SNPs (rs145224844, rs139620330, rs144273480, rs1611770, rs146141676, rs201798179, rs201815857, rs199840128, rs200788986, rs141460657, rs183700327, rs199768496, rs191544901, rs200639498, rs148332231, and rs11465209) of MUC1 gene and eight SNPs (rs1104760, rs1106502, rs882605, rs2291651, rs2291652, rs2291653, rs2291654, and rs375068067) of the MUC4 gene were identified. We amplified SNP sites by polymerase chain reaction (PCR) using specific primer sets followed by DNA sequencing.

RESULTS

The single mutation analysis of MUC4 showed that MUC4 mutations had no effect on the risk for endometriosis, but the frequencies of haplotypes [T/T + T/T + C/C] (rs2291653, 2291654 and rs375068067) were associated with endometriosis.

CONCLUSION

The MUC1 genotype may not be correlated with endometriosis susceptibility. However, MUC4 polymorphisms are associated with the risk for endometriosis in Korean women.

Invasion of human deep nodular endometriotic lesions is associated with collective cell migration and nerve development

OBJECTIVE

To study the mechanisms of invasion and innervation of deep endometriosis in women.

DESIGN

Morphologic and immunohistochemical analysis of human endometriotic lesions.

SETTING

Academic research unit.

PATIENT(S)

Seventeen biopsy samples of deep endometriotic lesions were collected from patients undergoing surgery for deep endometriosis.

INTERVENTION(S)

The endometriotic samples were divided into two parts: the front (the most invasive area of lesions, approaching rectal infiltration) and center (the area close to the posterior part of the cervix).

MAIN OUTCOME(S)

To elucidate: gland morphology, proliferation, and expression of adhesion molecules (β-catenin, E-cadherin, and N-cadherin) to determine the possible role of collective cell migration (CCM) in the invasion process; and nerve growth factor (NGF) and nerve fiber density (NFD) values to shed further light on the mechanism of innervation.

RESULTS

Glands from the front showed significantly reduced thickness, but significantly higher proliferation. β-Catenin expression was similar between the lesion center and front. E-cadherin levels were significantly lower and N-cadherin levels significantly higher in glands located at the front of the lesions. Expression of matrix metalloproteinase-9 was significantly higher in glands and stromal cells located at the invasion front. NFD and NGF expression were also significantly higher at the lesion front.

CONCLUSION

Although some data in the literature point to features of epithelial to mesenchymal transition in human deep nodular endometriosis, our study suggests that gland invasion in these lesions is dominated by CCM. Innervation of deep nodular endometriotic lesions may be a consequence of nerve recruitment from surrounding organs.

Upregulation of miR‑33b promotes endometriosis via inhibition of Wnt/β‑catenin signaling and ZEB1 expression

The present study aimed to investigate the role and mechanisms of microRNA (miR)‑33b in endometriosis (Ems). Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), MTT assays, flow cytometry, caspase‑3/9 activity assays and western blotting were performed in the present study. Initially, miR‑33b expression in an Ems rat model was investigated by RT‑qPCR and was demonstrated to be upregulated in Ems tissue samples of rats compared with the control group. In addition, miR‑33b upregulation inhibited cell growth and enhanced apoptosis in an Ems model (primary cell cultures) compared with the control group. In addition, miR‑33b up‑regulation reduced Wnt/β‑catenin signaling pathway and suppressed zinc finger E‑box‑binding homeobox 1 (ZEB1) protein expression in the in vitro Ems model (primary cell cultures) compared with the control group. Furthermore, small interfering‑ZEB1 ameliorated the effects of miR‑33b downregulation on Ems cell growth in the in vitro Ems model. Additionally, a Wnt agonist reduced the effects of miR‑33b upregulation on Ems cell growth in the in vitro Ems model. In conclusion, the present study demonstrated that upregulation of miR‑33b may promote Ems through Wnt/β‑catenin by ZEB1 expression.

The activation of BDNF reduced inflammation in a spinal cord injury model by TrkB/p38 MAPK signaling

The aim of the present study was to investigate the pro-inflammation effects of brain-derived neurotrophic factor (BDNF) signaling in promoting inflammation following spinal cord injury (SCI) in rats. Reverse transcription-quantitative polymerase chain reaction was used to detect the expression of BDNF in SCI rats. The Basso, Beattie and Bresnahan (BBB) test was used and the water content of spinal cord were assessed to determine the effects of BDNF on SCI. BDNF expression was increased in SCI rats. In an in vitro model, overexpression of BDNF induced the protein expression of tyrosine kinase receptor B (TrkB) and suppressed that of phosphorylated (p-)p38, and reduced inflammation, as indicated by tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-18, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 levels. Conversely, the TrkB inhibitor ANA-12 suppressed the protein expression of TrkB and induced that of p-p38, and promoted inflammation (as indicated by TNF-α, IL-1β, IL-6, IL-18, iNOS and COX-2 levels) in an in vitro model of SCI by BDNF overexpression. In addition, the p38 inhibitor TA-0, suppressed p38 protein expression and reduced inflammation in an in vitro model of SCI by BDNF overexpression. Together, these data suggest that the pro-inflammation effects of BDNF/TrkB promoted inflammation in SCI through p38 signaling in rats.

Anti-endometriosis Mechanism of Jiawei Foshou San Based on Network Pharmacology

Jiawei Foshou San (JFS) is the new formula originated from classic Foshou San formula, composed with ligustrazine, ferulic acid, and tetrahydropalmatine. Previously JFS inhibited the growth of endometriosis (EMS) with unclear mechanism, especially in metastasis, invasion, and epithelial-mesenchymal transition. In this study, network pharmacology was performed to explore potential mechanism of JFS on EMS. Through compound-compound target and compound target-EMS target networks, key targets were analyzed for pathway enrichment. MMP-TIMP were uncovered as one cluster of the core targets. Furthermore, autologous transplantation of EMS rat's model were used to evaluate in vivo effect of JFS on invasion, metastasis and epithelial-mesenchymal transition. JFS significantly suppressed the growth, and reduced the volume of ectopic endometrium, with modification of pathologic structure. In-depth study, invasion and metastasis were restrained after treating with JFS through decreasing MMP-2 and MMP-9, increasing TIMP-1. Meanwhile, JFS promoted E-cadherin, and attenuated N-cadherin, Vimentin, Snail, Slug, ZEB1, ZEB2, Twist. In brief, anti-EMS effect of JFS might be related to the regulation of epithelial-mesenchymal transformation, thereby inhibition of invasion and metastasis. These findings reveal the potential mechanism of JFS on EMS and the benefit for further evaluation.

Similar Characteristics of Endometrial and Endometriotic Epithelial Cells

Epithelial-mesenchymal transition (EMT) is characterized by the loss of epithelial and acquisition of mesenchymal cell characteristics. Our aim was to assess the epithelial phenotype in the pathogenesis of endometriosis with epithelial and mesenchymal markers. We used 2 structural (keratin-18, -19 [K18, K19]), 1 membrane-associated (mucin-1 [MUC1]), and 2 mesenchymal proteins (vimentin; zinc finger E-box-binding homeobox 1, [ZEB1]) to compare epithelial and mesenchymal characteristics in eutopic endometrium with the 3 endometriotic entities, peritoneal, ovarian, and deep infiltrating endometriosis (DIE). Quantitation showed no differences for K18, K19, and MUC1 between endometrium with and without endometriosis. Also, K18 was not different between endometrium and endometriotic lesions. In contrast, K19 and MUC1 were modestly but significantly decreased in the endometriotic lesions compared to endometrium. However, the maintained expression of epithelial markers in all investigated tissues, regardless of the pathological condition, clearly indicates no loss of the epithelial phenotype. This is further supported by the reduced presence of epithelial vimentin in endometriotic lesions which is in contrast to an increase in stromal vimentin in ectopic endometrium, especially in ovarian endometriosis. The ZEB1 increase in endometriotic lesions, especially in DIE, on the other hand suggests a role of partial EMT in the development of endometriotic lesions, possibly connected with the gain of invasive capabilities or stemness. Taken together, although we found some hints for at least a partial EMT, we did not observe a severe loss of the epithelial cell phenotype. Thus, we propose that EMT is not a main factor in the pathogenesis of endometriosis.