The Immunopathophysiology of Endometriosis

The bidirectional relationship between endometriosis and microbiome

Endometriosis has been described by many different theories of pathogenesis over the years. It is now also appreciated to be a state of chronic inflammation, and the role of immune dysfunction in its development has been proven. There is increasing evidence to support the role of the microbiome in the formation and progression of endometriosis via inflammatory pathways. The dysbiosis seen in endometriosis is thought to be both causative and a consequence of the pathogenesis. Gut, peritoneal fluid and female reproductive tract microbiota has been studied to understand if there are any microbiome signatures specific to endometriosis. New research on how to manipulate the microbiome for better detection and treatment of endometriosis is emerging.

Focus on the role of NLRP3 inflammasome in the pathology of endometriosis: a review on molecular mechanisms and possible medical applications

Endometriosis (EMS) is a gynecological disease that leads to pathological conditions, which are connected to the initiation of pro-inflammatory cytokine production. Inflammation plays a vital role in the pathogenesis of EMS. The activation and formation of cytoplasmic inflammasome complexes is considered an important step of inflammation and a key regulator of pyroptosis, a form of cell death. NLR family pyrin domain containing 3 (NLRP3) inflammasome complex modulates innate immune activity and inflammation. The NLRP3 inflammasome activates cysteine protease caspase-1, which produces active pro-inflammatory interleukins (ILs), including IL-1β and IL-18. The aim of this review article was to discuss the involvement of NLRP3 inflammasome assembly and its activation in the pathophysiology of EMS and target related pathways in designing appropriate therapeutic approaches. Dysregulation of sex hormone signaling pathways was associated with over-activation of the NLPR3 inflammasome. In this study, we demonstrated the involvement of NLRP3 inflammasome signaling pathways in the pathophysiology of EMS. The manuscript also discusses the beneficial effects of targeted therapy through synthetic inhibitors of NLRP3 signaling pathways to control EMS lesions.

Exosomes from the Uterine Cavity Mediate Immune Dysregulation via Inhibiting the JNK Signal Pathway in Endometriosis

Endometriosis is a chronic inflammatory disease with an uncertain pathogenesis. Peritoneal immune dysregulation plays an important role in the pathogenesis of endometriosis. Exosomes are messengers of intercellular communication. This study mainly investigated the role of exosomes from the uterine cavity in endometriosis. Exosomes of the uterine aspirate fluid were isolated and cocultured with macrophages for 48 h. Flow cytometry was used to detect macrophage polarization. A Human MAPK Phosphorylation Antibody Array and Western blot were used to detect the phosphorylation of the MAPK pathway. A microRNA sequencing analysis was used to detect differentially expressed miRNAs. Our research found that exosomes of the uterine aspirate fluid from endometriosis could reduce the proportion of CD80⁺ macrophages. Additionally, it could inhibit the expression of P-JNK in macrophages. However, the JNK activator anisomycin could increase the proportion of CD80⁺ macrophages. In addition, exosomes of the uterine aspirate fluid from endometriosis could promote the migration and invasion of endometrial stromal cells by acting on macrophages. The expression of miR-210-3p was increased in both exosomes and the eutopic endometrium in patients with endometriosis through miRNA sequencing, which could also reduce the proportion of CD80⁺ macrophages. In summary, we propose that exosomes from the uterine cavity in patients with endometriosis may affect the phenotype of macrophages by inhibiting the JNK signaling pathway, thus mediating the formation of an immunological microenvironment conducive to the development of endometriosis.

Strategies for modelling endometrial diseases

Each month during a woman's reproductive years, the endometrium undergoes vast changes to prepare for a potential pregnancy. Diseases of the endometrium arise for numerous reasons, many of which remain unknown. These endometrial diseases, including endometriosis, adenomyosis, endometrial cancer and Asherman syndrome, affect many women, with an overall lack of efficient or permanent treatment solutions. The challenge lies in understanding the complexity of the endometrium and the extensive changes, orchestrated by ovarian hormones, that occur in multiple cell types over the period of the menstrual cycle. Appropriate model systems that closely mimic the architecture and function of the endometrium and its diseases are needed. The emergence of organoid technology using human cells is enabling a revolution in modelling the endometrium in vitro. The goal of this Review is to provide a focused reference for new models to study the diseases of the endometrium. We provide perspectives on the power of new and emerging models, from organoids to microfluidics, which have opened up a new frontier for studying endometrial diseases.

Bioinformatics identification and validation of biomarkers and infiltrating immune cells in endometriosis

Background

Endometriosis (EM) is a common gynecological disorder that often leads to irregular menstruation and infertility. The pathogenesis of EM remains unclear and delays in diagnosis are common. Thus, it is urgent to explore potential biomarkers and underlying molecular mechanisms for EM diagnosis and therapies.

Methods

Three EM-related datasets (GSE11691, GSE25628, and GSE86534) were downloaded from the Gene Expression Omnibus (GEO) which were integrated into a combined dataset after removing batch effect. Differentially expressed immune cell-related genes were obtained by CIBERSORT, WGCNA, and the identification of differentially expressed genes. Random forest model (RF), support vector machine model (SVM), and generalized linear model (GLM) were then constructed and the biomarkers for EM were determined. A nomogram evaluating the risk of disease was constructed and the validity was assessed by the calibration curve, DCA curve, and clinical impact curve. Single-gene Gene Set Enrichment Analysis (GSEA)was performed to explore the molecular mechanisms of biomarkers. The ceRNA regulatory network of biomarkers was created by Cytoscape and potential target drugs were obtained in the DGIdb database (Drug-Gene Interaction database).The expression levels of biomarkers from clinical samples was quantified by RT-qPCR.

Results

The ratio of eight immune cells was significantly different between the eutopic and ectopic endometrium samples. A total of eight differentially expressed immune cell-related genes were investigated. The SVM model was a relatively suitable model for the prediction of EM and five genes (CXCL12, PDGFRL, AGTR1, PTGER3, and S1PR1) were selected from the model as biomarkers. The calibration curve, DCA curve, and clinical impact curve indicated that the nomogram based on the five biomarkers had a robust ability to predict disease. Single gene GSEA result suggested that all five biomarkers were involved in labyrinthine layer morphogenesis and transmembrane transport-related biological processes in EM. A ceRNA regulatory network containing 184 nodes and 251 edges was constructed. Seven drugs targeting CXCL12, 49 drugs targeting AGTR1, 16 drugs targeting PTGER3, and 21 drugs targeting S1PR1 were extracted as potential drugs for EM therapy. Finally, the expression of PDGFRL and S1PR1 in clinical samples was validated by RT-qPCR, which was consistent with the result of public database.

Conclusions

In summary, we identified five biomarkers (CXCL12, PDGFRL, AGTR1, PTGER3, and S1PR1) and constructed diagnostic model, furthermore predicted the potential therapeutic drugs for EM. Collectively, these findings provide new insights into EM diagnosis and treatment.

The gut microbiota and endometriosis: From pathogenesis to diagnosis and treatment

Endometriosis is a common gynecological disease, that often leads to pain and infertility. At present, the specific pathogenesis of endometriosis has not been clarified, but it may be closely related to an imbalance of sex hormones in the body, ectopic hyperplasia stimulated by immune inflammation, and invasion and escape based on tumor characteristics. Gut microbiota is associated with many inflammatory diseases. With the further study of the gut microbiota, people are paying increasing attention to its relationship with endometriosis. Studies have shown that there is an association between the gut microbiota and endometriosis. The specific ways and mechanisms by which the gut microbiota participates in endometriosis may involve estrogen, immune inflammation, and tumor characteristics, among others. Therefore, in the future, regulating gut microbiota disorders in various ways can help in the treatment of endometriosis patients. This study reviewed the research on the gut microbiota and endometriosis in order to provide ideas for clinical diagnosis and treatment.

Pathophysiology, diagnosis, and management of endometriosis

Endometriosis affects approximately 190 million women and people assigned female at birth worldwide. It is a chronic, inflammatory, gynecologic disease marked by the presence of endometrial-like tissue outside the uterus, which in many patients is associated with debilitating painful symptoms. Patients with endometriosis are also at greater risk of infertility, emergence of fatigue, multisite pain, and other comorbidities. Thus, endometriosis is best understood as a condition with variable presentation and effects at multiple life stages. A long diagnostic delay after symptom onset is common, and persistence and recurrence of symptoms despite treatment is common. This review discusses the potential genetic, hormonal, and immunologic factors that lead to endometriosis, with a focus on current diagnostic and management strategies for gynecologists, general practitioners, and clinicians specializing in conditions for which patients with endometriosis are at higher risk. It examines evidence supporting the different surgical, pharmacologic, and non-pharmacologic approaches to treating patients with endometriosis and presents an easy to adopt step-by-step management strategy. As endometriosis is a multisystem disease, patients with the condition should ideally be offered a personalized, multimodal, interdisciplinary treatment approach. A priority for future discovery is determining clinically informative sub-classifications of endometriosis that predict prognosis and enhance treatment prioritization.

Changes in MCP-1, HGF, and IGF-1 expression in endometrial stromal cells, PBMCs, and PFMCs of endometriotic women following 1,25(OH)2D3 treatment

1,25(OH)2D3 has anti‐inflammatory and growth inhibitory effects. Our study explored the effect of 1,25(OH)2D3 treatment on the expression of monocyte chemotactic protein‐1 (MCP‐1), hepatocyte growth factor (HGF), and insulin‐like growth factor‐1 (IGF‐1) by peripheral blood mononuclear cells (PBMCs), peritoneal fluid mononuclear cells (PFMCs), endometrial stromal cells (ESCs), and its effect on the proliferation of PBMCs and PFMCs of patients with endometriosis compared with controls. PBMCs, PFMCs, and ESCs were obtained from 10 endometriosis patients and 10 non‐endometriotic individuals. After treating cells with 0.1 μM of 1,25(OH)2D3 for 6, 24, and 48 h, the gene and protein expression of mentioned factors were evaluated by real‐time PCR and ELISA methods, respectively. 1,25(OH)2D3 treatment significantly reduced the protein expression of MCP‐1, HGF, and IGF‐1 in PBMCs and PFMCs of endometriotic patients at 48 h (p < 0.05–<0.01). Also, this treatment significantly reduced MCP‐1, HGF, and IGF‐1 gene and/or protein expression in EESCs and EuESCs at 24 and 48 h (p < 0.05–<0.01). 1,25(OH)2D3 treatment also reduced the proliferation of PBMCs and PFMCs of endometriotic patients compared with controls (p < 0.01). 1,25(OH)2D3 can be considered as a potentially effective agent in the prevention and treatment of endometriosis along with other therapies.

Colocalization of senescent biomarkers in deep, superficial, and ovarian endometriotic lesions: a pilot study

Endometriosis is a prevalent gynecological condition with deleterious effects on women's quality of life in terms of physical, emotional, and social compromise. It is an inflammatory disease characterized by the presence of endometrial-like tissue outside the uterus, and its presentation varies from superficial peritoneal lesions to deep infiltrative endometriosis and ovarian endometrioma. In our previous study, endometriotic lesions were implicated in cellular senescence as their inflammatory pattern could potentially compromise surrounding tissue integrity, thereby inducing a senescent state in cells. P16^Ink4a and lamin b1 are biomarkers used to assess cellular senescence. Indirect immunofluorescence staining is a broad technique used to assess cellular structure and behavior driven by protein-protein interactions that provide valuable information about cell functioning. The etiopathogeny of endometriosis is not completely understood and diagnostic approaches still rely on invasive methods; therefore, it is important to use validated methods to increase our understanding of the disease and the development of novel diagnostic tools. However, indirect immunofluorescence protocols are often tissue specific and, if neglected, can lead to misinterpretation of results. Moreover, no valid endometriotic tissue-specific colocalization immunofluorescence protocols have been established. Thus, we have validated a well-funded and suitable protocol to allow precise evaluation of the three presentations of endometriosis lesions using indirect immunofluorescence aiming to support further investigations in endometriosis lesions.

Role of the endocannabinoid system in the pathophysiology of endometriosis and therapeutic implications

Endometriosis patients experience debilitating chronic pain, and the first-line treatment is ineffective at managing symptoms. Although surgical removal of the lesions provides temporary relief, more than 50% of the patients experience disease recurrence. Despite being a leading cause of hysterectomy, endometriosis lacks satisfactory treatments and a cure. Another challenge is the poor understanding of disease pathophysiology which adds to the delays in diagnosis and overall compromised quality of life. Endometriosis patients are in dire need of an effective therapeutic strategy that is both economical and effective in managing symptoms, while fertility is unaffected. Endocannabinoids and phytocannabinoids possess anti-inflammatory, anti-nociceptive, and anti-proliferative properties that may prove beneficial for endometriosis management, given that inflammation, vascularization, and pain are hallmark features of endometriosis. Endocannabinoids are a complex network of molecules that play a central role in physiological processes including homeostasis and tissue repair, but endocannabinoids have also been associated in the pathophysiology of several chronic inflammatory diseases including endometriosis and cancers. The lack of satisfactory treatment options combined with the recent legalization of recreational cannabinoids in some parts of the world has led to a rise in self-management strategies including the use of cannabinoids for endometriosis-related pain and other symptoms. In this review, we provide a comprehensive overview of endocannabinoids with a focus on their potential roles in the pathophysiology of endometriosis. We further provide evidence-driven perspectives on the current state of knowledge on endometriosis-associated pain, inflammation, and therapeutic avenues exploiting the endocannabinoid system for its management.

A Systematic Review and Meta-Analysis of the Efficacy of Uterine Artery Embolization in the Treatment of Endometriosis

Objective

To compare the efficacy of uterine artery embolization (UAE) with traditional methods for treating endometriosis.

Methods

The randomized controlled trials of uterine artery embolization and other medical treatments for endometriosis in PubMed, Embase, Web of Science, Cochrane Library, China Journal Full-Text Database, Wanfang Database, VIP Database, and China Biomedical Literature Database were retrieved by computer. The search time was up to June 2022. The quality of articles was evaluated by Cochrane ROB 2.0, and meta-analysis was performed by Stata15.1 software.

Results

7 studies were finally included. Meta-analysis showed that the serum CA125 level after uterine artery embolization was significantly lower than that in the control group (SMD = -0.85, 95%CI (-1.12, -0.59)], and the postoperative visual analogue scale (VAS) of dysmenorrhea was significantly lower than that in the control group (SMD = -1.86, 95%CI (-2.21, -1.50)) There was no significant difference in the effective rate, FSH level, E2 level, and LH level between the two groups.

Conclusion

UAE can effectively reduce the VAS score of dysmenorrhea and serum CA125 level for treating endometriosis. However, due to the limitation of the quality of included articles, more large sample size and high quality RCTs are needed to provide stronger evidence-based medicine evidence for clinical practice.

CTLA4-Linked Autoimmunity in the Pathogenesis of Endometriosis and Related Infertility: A Systematic Review

Several studies, although with conflicting results, have sought to determine the concentration of soluble CTLA4 antigens in peripheral blood plasma and peritoneal fluid in patients with endometriosis-related infertility. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) through a search of the following databases: MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database and Web of Science, and Clinical Trials research register. We included observational or prospective human and animal studies with any features related to endometriosis and/or infertility studies involving CTLA4-related pathogenesis published in English. The results of studies in which the size and characteristics of the observed groups were not stated were excluded. From the initial pool of 73 publications identified and screened, we finally included 5 articles to summarize the most recent knowledge about CTLA4-linked autoimmunity in the pathogenesis of endometriosis and related infertility. Evidence from clinical studies shows that CTLA4-based autoimmunity is involved in the maintenance of chronic inflammation in the peritoneal environment, with pre-clinical evidence of anti-CTLA antibodies as a potential novel target therapy for endometriosis. However, CTLA4 gene analyses do not support findings of CTLA4-linked autoimmunity as a primary determinant of the pathogenesis of endometriosis. These findings underlie the role of complex interactions within the family of immune checkpoint molecules involved. Further studies are needed to investigate the clinical relevance of anti-CTLA target therapy, taking into account the potential adverse events and repercussions of novel immunologic therapy modalities. However, with the general scarcity of studies investigating this topic, the clinical importance of CTLA4 autoimmunity still remains unclear.

Potential impact of COVID-19 pandemic on endometriosis

The impact of coronavirus disease 2019 (COVID-19) on endometriosis (EM) is currently unclear. Here, we aimed to describe the potential influence of COVID-19 on the pathogenesis, clinical symptoms, and treatment of EM. The cytokine storm caused by COVID-19 may induce the occurrence and progression of EM, and immunosuppression of COVID-19 may help the ectopic endometrium escape from immune clearance. Consequently, the forced social isolation and the cancelation of non-emergency medical treatment during the COVID-19 pandemic aggravate anxiety and psychological pressure, which can aggravate the symptoms related to EM and delay routine medical services.

Evaluation of the potential role of diethylstilbestrol on the induction of endometriosis in a rat model - An alternative approach

Endometriosis is known to be a gynaecological condition characterised by persistent inflammation and abnormal development of endometrial stroma and glands. Researchers require a rodent model to analyse the disease environment. Animal models are the best option for investigating the etiology and effective treatment of debilitating illnesses in women since rodents, like humans, menstruate. In order to develop the model system, diethylstilbestrol (DES) was examined for its ability to induce endometriosis in rats by investigating its effect on the estrus cycle, hormones, and key markers. The results demonstrated that animals given DES had an erratic estrus cycle and aberrant hormone levels. Histomorphology revealed the development of an endometriosis environment with degenerative epithelium and enlarged glandular cells after DES induction. The higher levels of estrogen, progesterone, and MCP-1 were shown in the endometriosis induced animals. Endometriosis-induced groups had decreased levels of HOXA10 and HOXA11 and increased levels of VEGF and COX-2. Finally, the DES demonstrated endometriosis induction efficacy, implying that it might be a viable replacement for endometriosis induction.

Influence of the gut microbiota on endometriosis: Potential role of chenodeoxycholic acid and its derivatives

The gut microbiota (GM) has received extensive attention in recent years, and its key role in the establishment and maintenance of health and in the development of diseases has been confirmed. A strong correlation between the GM and the progression of endometriosis (EMS) has been observed in emerging research. Alterations in the composition and function of the GM have been described in many studies on EMS. In contrast, the GM in the environment of EMS, especially the GM metabolites, such as bile acids and short-chain fatty acids that are related to the pathogenesis of EMS, can promote disease progression. Chenodeoxycholic acid (CDCA), as one of the primary bile acids produced in the liver, is metabolized by various enzymes derived from the GM and is critically important in maintaining intestinal homeostasis and regulating lipid and carbohydrate metabolism and innate immunity. Given that the complexity of CDCA as a signalling molecule and the interaction between the GM and EMS have not been clarified, the role of the CDCA and GM in EMS should be understood from a novel perspective. However, few articles on the relationship between CDCA and EMS have been reviewed. Therefore, we review the available and possible potential links between CDCA, the GM and EMS and put forward the hypothesis that CDCA and its derivative obeticholic acid can improve the symptoms of EMS through the GM.

Integrated bioinformatics analysis uncovers characteristic genes and molecular subtyping system for endometriosis

Objective: Endometriosis is a chronic inflammatory estrogen-dependent disease with the growth of endometrial tissues outside the uterine cavity. Nevertheless, the etiology of endometriosis is still unclear. Integrated bioinformatics analysis was implemented to reveal the molecular mechanisms underlying this disease.

Methods: A total of four gene expression datasets (GSE7305, GSE11691, GSE23339, and GSE25628) were retrieved from the GEO, which were merged into a meta-dataset, followed by the removal of batch effects via the sva package. Weighted gene co-expression network analysis (WGCNA) was implemented, and endometriosis-related genes were screened under normal and endometriosis conditions. Thereafter, characteristic genes were determined via Lasso analysis. The diagnostic performance was estimated via receiver operating characteristic curves, and epigenetic and post-transcriptional modifications were analyzed. Small molecular compounds were predicted. Unsupervised clustering analysis was conducted via non-negative matrix factorization algorithm. The enriched pathways were analyzed via gene set enrichment analysis or GSVA. Immune features were evaluated according to immune-checkpoints, HLA, receptors, chemokines, and immune cells.

Results: In total, four characteristic genes (BGN, AQP1, ELMO1, and DDR2) were determined for endometriosis, all of which exhibited the favorable efficacy in diagnosing endometriosis. Their aberrant levels were modulated by epigenetic and post-transcriptional modifications. In total, 51 potential drugs were predicted against endometriosis. The characteristic genes exhibited remarkable associations with immunological function. Three subtypes were classified across endometriosis, with different mechanisms and immune features.

Conclusion: Our study reveals the characteristic genes and novel molecular subtyping of endometriosis, contributing to the early diagnosis and intervention in endometriosis.

T helper 17 axis and endometrial macrophage disruption in menstrual effluent provides potential insights into the pathogenesis of endometriosis

OBJECTIVE

To identify immune cells, cytokines, and immune cell transcriptome in the menstrual effluent (ME) of women with endometriosis compared with that of healthy donors.

DESIGN

Live immune cells were isolated from human ME samples and were analyzed by flow cytometry to identify various immune cell populations. Selected cytokines from the same patients were evaluated using multiplex cytokine analyses. The transcriptome of the immune cell population was subsequently profiled using NanoString nCounter's PanCancer Immune panel.

SETTING

Academic institution.

PATIENT(S)

Surgically confirmed endometriosis patients (n = 14) and healthy fertile donors (n = 19).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

In-depth immune cell profiling of ME obtained from women with endometriosis compared with that of healthy donors.

RESULT(S)

ME analysis revealed that the number of T helper 17 (T_H17) cells was significantly lower in patients with endometriosis compared with that of healthy donors; the number of macrophages was also lower (P=.06) in the former. Multiplex cytokine analysis revealed significantly lower transforming growth factor α in the ME "serum" of patients with endometriosis. Transcriptomic analysis of CD45⁺ cells revealed 47 differentially expressed genes, mainly associated with the T_H17 axis (IL10, IL23A, and IL6), as well as genes associated with macrophage signaling/activation (CD74, CD83, CXCL16, and CCL3).

CONCLUSION(S)

We demonstrate for the first time that the levels of T_H17 axis, macrophages, and transforming growth factor α were altered in the ME of women with endometriosis compared with that of healthy donors. These findings shed light on the potential immune pathways that could partly explain the pathogenesis and progression of endometriosis. Future large-scale studies on ME samples are warranted to exploit the use of these markers to study the pathogenesis of endometriosis.

Zearalenone affects the growth of endometriosis via estrogen signaling and inflammatory pathways

Endometriosis is a chronic, inflammatory, estrogen-dependent gynecological disease characterized by the growth of endometrial stromal cells and glands outside the uterine cavity in response to hormones, which commonly occurs in reproductive-age women. Zearalenone (ZEA) is a toxic metabolite produced by Fusarium, which acts as estrogen activity because of the similarity of its structure to estrogen. In this study, we used an endometriosis mouse model: 15 days after ovariectomy, endometrial fragments were sutured on the pelvic wall, and exogenous estrogen was supplied using an estrogen-releasing silicone tube embedded subcutaneously. Mice were treated with different doses of ZEA by gavage for 21 days. The results show that ZEA significantly inhibited the growth of ectopic endometrium in a dose-dependent manner. The proliferation of cells decreased while apoptosis increased in the ectopic tissues of ZEA-treated mice compared to the vehicle group. The expression of estrogen receptor-α and its downstream targets MUC1 and p-AKT decreased, indicating an impaired estrogen signaling activity by ZEA treatment. In addition, the decreased expression of pro-inflammatory cytokine Tnf-α, Il-1β, and Il-6, the lower number of macrophages and neutrophils cells, and the inhibited NF-κB signaling pathway suggest the inflammatory response in the ectopic endometrium was also suppressed by ZEA treatment. However, when the exogenous estrogen supply is removed, ZEA, in turn, plays an estrogen-like role that promotes cell proliferation in the ectopic endometrium. In summary, our data suggest ZEA acts as an antagonist in endometriotic tissue when estrogen is sufficient but turns to estrogenic activity in the absence of estrogen in the development of endometriosis. ZEA also inhibits ectopic tissue growth by inhibiting inflammatory response in the endometriosis model.

Single-cell analysis of endometriosis reveals a coordinated transcriptional programme driving immunotolerance and angiogenesis across eutopic and ectopic tissues

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus. It affects many women during their reproductive age, causing years of pelvic pain and potential infertility. Its pathophysiology remains largely unknown, which limits early diagnosis and treatment. We characterized peritoneal and ovarian lesions at single-cell transcriptome resolution and compared them to matched eutopic endometrium, unaffected endometrium and organoids derived from these tissues, generating data on over 122,000 cells across 14 individuals. We spatially localized many of the cell types using imaging mass cytometry. We identify a perivascular mural cell specific to the peritoneal lesions, with dual roles in angiogenesis promotion and immune cell trafficking. We define an immunotolerant peritoneal niche, fundamental differences in eutopic endometrium and between lesion microenvironments and an unreported progenitor-like epithelial cell subpopulation. Altogether, this study provides a holistic view of the endometriosis microenvironment that represents a comprehensive cell atlas of the disease in individuals undergoing hormonal treatment, providing essential information for future therapeutics and diagnostics.

An Update on the Multifaceted Role of NF-kappaB in Endometriosis

Endometriosis remains a common but challenging gynecological disease among reproductive-aged women with an unclear pathogenesis and limited therapeutic options. Numerous pieces of evidence suggest that NF-κB signaling, a major regulator of inflammatory responses, is overactive in endometriotic lesions and contributes to the onset, progression, and recurrence of endometriosis. Several factors, such as estrogen, progesterone, oxidative stress, and noncoding RNAs, can regulate NF-κB signaling in endometriosis. In the present review, we discuss the mechanisms by which these factors regulate NF-κB during endometriosis progression and provide an update on the role of NF-κB in affecting endometriotic cells, peritoneal macrophages (PMs) as well as endometriosis-related symptoms, such as pain and infertility. Furthermore, the preclinical drugs for blocking NF-κB signaling in endometriosis are summarized, including plant-derived medicines, NF-κB inhibitors, other known drugs, and the potential anti-NF-κB drugs predicted through the Drug-Gene Interaction Database. The present review discusses most of the studies concerning the multifaceted role of NF-κB signaling in endometriosis and provides a summary of NF-κB-targeted treatment in detail.

The Gut Microbiota: A Double Edge Sword in Endometriosis

Endometriosis that afflicts 1 in 10 women of reproductive age is characterized by growth of endometrial tissue in the extra-uterine sites and encompasses metabolic-, immunologic- and endocrine-disruption. Importantly, several comorbidities are associated with endometriosis, especially autoimmune disorders such as inflammatory bowel disease. Primarily thought of as a condition arising from retrograde menstruation, emerging evidence uncovered a functional link between the gut microbiota and endometriosis. Specifically, recent findings revealed altered gut microbiota profiles in endometriosis and in turn this altered microbiota appears to be causal in the disease progression, implying a bi-directional crosstalk. In this review, we discuss the complex etiology and pathogenesis of endometriosis emphasizing on this recently recognized role of gut microbiome. We review the gut microbiome structure and functions and its complex network of interactions with the host for maintenance of homeostasis that is crucial for disease prevention. We highlight the underlying mechanisms on how some bacteria promotes disease progression and others protects against endometriosis. Further, we highlight the areas that require future emphases in the gut microbiome-endometriosis nexus and the potential microbiome-based therapies for amelioration of endometriosis.

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

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

O-Glycosylation Changes in Serum Immunoglobulin G Are Associated with Inflammation Development in Advanced Endometriosis

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly related to inflammatory processes with an immune basis. Our study aimed to analyze the O-glycosylation of native serum IgG and IgG isolated from sera of women with advanced endometriosis, without endometriosis but with benign gynecological diseases, and from a control group of healthy women, in the context of its utility for differentiation of advanced endometriosis from the other two groups of women studied. For the analysis of serum IgG O-glycosylation and the expression of multi-antennary N-glycans, lectin-ELISA with lectins specific to O-glycans (MPL, VVL, and Jacalin) and highly branched N-glycans (PHA-L) was used. The relative reactivities of isolated serum IgG O-linked glycans with specific lectins as well as the MPL/VVL O-glycosylation ratio were significantly higher in patients with advanced endometriosis and those with other gynecological diseases when compared to the control group of healthy women. We also showed significantly higher expression of PHA-L-reactive multi-antennary N-glycans in isolated IgG in the advanced endometriosis and the non-endometriosis groups in comparison to the control group. Additionally, significantly higher expression of Jacalin-reactive O-glycans in isolated IgG was observed in the non-endometriosis than in the advanced endometriosis group. The results of the ROC curve and cluster analysis additionally confirmed that the lectin-based analysis of isolated serum IgG O-glycosylation and the expression of highly branched N-glycans may help distinguish women with advanced endometriosis from healthy women. Moreover, the analysis of the expression of Jacalin-reactive i-IgG O-glycans may be helpful in differentiation between women with advanced endometriosis and patients with other gynecological diseases with an inflammatory background. In the case of non-endometriosis patients, the observed differences were most probably caused by increased expression of core 3 type O-glycans.

COVID-19 susceptibility in endometriosis patients: a case control study

PROBLEM

Starting from November 2019, the world has had to face a devastating pandemic caused by SARS-CoV-2. Various studies have identified potential risk factors facilitating the infection, however it hasn't been demonstrated whether endometriosis might represent one of them. The purpose of this study was to evaluate if patients with endometriosis had a higher risk of contracting COVID-19 infection and, in such case, whether they developed a more severe infection than the general population. Furthermore, this study evaluated the possible correlation with the stage of endometriosis, based on the r-ASRM score, and the potential worsening of the disease during the SARS-CoV-2 infection.

METHOD OF STUDY

A case-control study was conducted from March 2020 to April 2021 at Macedonio Melloni Hospital, in Milan. A total of 401 women were recruited. The cases were 201 women with clinical or surgical diagnosis of endometriosis. The control group consisted of 200 women, without the disease. All women completed a self-administered questionnaire which evaluated their demographic and clinical characteristics, as well as a potential diagnosis of Covid-19.

RESULTS

Comparison between the two groups showed that women with endometriosis had a higher frequency of COVID-19 than the control subjects (23% vs 13.5%, P = 0.014), with a greater prevalence of fever (14.4% vs 6%, P = 0.008) and myalgias or arthralgias (11.4% vs 4.5%, P = 0.01). In multivariable logistic regression analyses, women with endometriosis had a higher risk of contracting SARS-CoV-2 infection (OR = 2.11, 95% IC: 1.20-3.80), regardless the stage of the disease.

CONCLUSION

Endometriosis increases the susceptibility to COVID-19, and women who suffer from it should be considered as fragile patients, worthy of prior access to SARS-CoV-2 vaccination campaign. This article is protected by copyright. All rights reserved.

Vaginal microecological characteristics of women in different physiological and pathological period

The vaginal microbiota, the host endocrine system, the vaginal anatomy, and the local mucosal immunity comprise the vaginal microbiota, which interacts with each other to maintain the balance of the vaginal microbiota, which maintains female reproductive health. Puberty, menstruation, pregnancy, and menopause are four phases women go through during their reproductive and post-reproductive years. Vaginal microbiota composition and abundance are heavily influenced by estrogen and progesterone, which start at puberty and continue during the reproductive years in a dynamic balance with some fluctuations. Estrogen promotes proliferation of vaginal epithelial cells and increases glycogen storage, while progesterone lyses vaginal epithelial cells, facilitating the release of glycogen to maintain normal pH. This review summarizes the latest national and international evidence on the composition and distribution of vaginal microecology in women during different physiological and pathological periods and proposes a hormone-driven microbial diversity hypothesis to explain the temporal patterns of vaginal microbial diversity during the female reproductive cycle and menopause. A relatively balanced vaginal microecological system has a positive effect on the maintenance of female health. An imbalance in the ratio of flora can lead to susceptibility to infections or reproductive complications. The study of human microecology and its role in the development and progression of human disease is essential for the prevention, diagnosis, and treatment of related obstetric and gynecologic conditions.

Analysis of characteristic genes and ceRNA regulation mechanism of endometriosis based on full transcriptional sequencing

Background: Endometriosis is a common gynecological disorder that usually causes infertility, pelvic pain, and ovarian masses. This study aimed to mine the characteristic genes of endometriosis, and explore the regulatory mechanism and potential therapeutic drugs based on whole transcriptome sequencing data and resources from public databases, providing a theoretical basis for the diagnosis and treatment of endometriosis.

Methods: The transcriptome data of the five eutopic (EU) and ectopic (EC) endometrium samples were obtained from Beijing Obstetrics and Gynecology Hospital, Beijing, China, and dinified as the own data set. The expression and clinical data of EC and EU samples in GSE25628 and GSE7305 datasets were obtained from the GEO database (https://www.ncbi.nlm.nih.gov/gds). Differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) were used to identify the endometriosis-related differentially expressed genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted by the “clusterProfiler” R package. Then, characteristic genes for endometriosis were identified by the least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) algorithm. The expression of characteristic genes was verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western-blot. The receiver operating characteristic (ROC) curve was used to evaluate the discriminatory ability of characteristic genes. We assessed the abundance of infiltrating immune cells in each sample using MCP-counter and ImmuCellAI algorithms. The competitive endogenous RNA (ceRNA) regulatory network of characteristic genes was created by Cytoscape and potential targeting drugs were obtained in the CTD database.

Results: 44 endometriosis-related differentially expressed genes were obtained from GSE25628 and the own dataset. Subsequently, LASSO and SVM-RFE algorithms identified four characteristic genes, namely ACLY, PTGFR, ADH1B, and MYOM1. The results of RT-PCR and western-blot were consistent with those of sequencing. The result of ROC curves indicated that the characteristic genes had powerful abilities in distinguishing EC samples from EU samples. Infiltrating immune cells analysis suggested that there was a certain difference in immune microenvironment between EC and EU samples. The characteristic genes were significantly correlated with specific differential immune cells between EC and EU samples. Then, a ceRNA regulatory network of characteristic genes was constructed and showed a total of 7, 11, 11, and 1 miRNA associated with ACLY, ADH1B, PTGFR, and MYOM1, respectively. Finally, we constructed a gene-compound network and mined 30 drugs targeting ACLY, 33 drugs targeting ADH1B, 13 drugs targeting MYOM1, and 12 drugs targeting PTGFR.

Conclusion: Comprehensive bioinformatic analysis was used to identify characteristic genes, and explore ceRNA regulatory network and potential therapeutic agents for endometriosis. Altogether, these findings provide new insights into the diagnosis and treatment of endometriosis.

CCL20/CCR6 axis mediates macrophages to promote proliferation and migration of ESCs by blocking autophagic flux in endometriosis

Background

Endometriosis (EMs) is a common benign gynecological disease that affects approximately 10% of females of reproductive age. Endometriosis ectopic lesions could recruit macrophages, which in turn facilitates endometriosis progression. Several studies have indicated that CCL20 derived from macrophages activates the expression of CCR6 in several cells and induces cell proliferation and migration. However, the function of the CCL20/CCR6 axis in the interactions between macrophages and endometriotic stromal cells (ESCs) in EMs has yet to be elucidated.

Methods

Ectopic and normal endometrial tissues were collected from 35 ovarian endometriosis patients and 21 control participants for immunohistochemical staining. It was confirmed that macrophages secreted CCL20 to promote CCR6 activation of ESCs during co-culture by ELISA, qRT-PCR and western blot analysis. CCK8 and Edu assays were used to detect cell proliferation, and wound healing and Transwell assay were used to detect cell migration. Autophagic flux was detected by measuring the protein expression levels of LC3 and P62by western blot and analyzing the red/yellow puncta after ESCs were transfected with mRFP-GFP-LC3 double fluorescence adenovirus (Ad‐LC3). Lysosomal function was tested by quantifying the fluorescent intensities of Lyso-tracker and Gal3 and activity of acid phosphatase. In addition, co-IP experiments verified the binding relationship between CCR6 and TFEB. Finally, the suppressive effect of CCL20-NAb on endometriosis lesions in vivo was demonstrated in mice models.

Results

We demonstrated that macrophages secreted CCL20 to promote CCR6 activation of ESCs during co-culture, which further induced the proliferation and migration of ESCs. We observed that the CCL20/CCR6 axis impaired lysosomal function and then blocked the autolysosome degradation process of autophagic flux in ESCs. The combination of CCR6 and TFEB to inhibit TFEB nuclear translocation mediates the role of the CCL20/CCR6 axis in the above process. We also found that co-culture with ESCs upregulated the production and secretion of CCL20 by macrophages. The suppression effect of CCL20-NAb on endometriosis lesions in vivo was demonstrated in mice models.

Conclusions

Our data indicate that macrophages block TFEB-mediated autolysosome degradation process of autophagic flux in ESCs via the CCL20/CCR6 axis, thereby promoting ESC proliferation and migration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02981-2.

The role of the Immune System in the Development of Endometriosis

Endometriosis is a chronic disease that affects about 10% of women of reproductive age. It can contribute to pelvic pain, infertility or other conditions such as asthma, cardiovascular disease, breast or ovarian cancer. Research has shown that one of the conditions for the development of endometrial lesions is the dysfunction of the immune system. It appears that immune cells, such as neutrophils, macrophages, NK cells and dendritic cells, may play a specific role in the angiogenesis, growth and invasion of endometriosis cells. Immune cells secrete cytokines and defensins that also affect the endometriosis environment. This review discusses the various components of the immune system that are involved in the formation of endometrial lesions in women.

Endometriosis: A Disease with Few Direct Treatment Options

Endometriosis is a gynecological condition characterized by the growth of endometrium-like tissues inside and outside the pelvic cavity. The evolution of the disease can lead to infertility in addition to high treatment costs. Currently, available medications are only effective in treating endometriosis-related pain; however, it is not a targeted treatment. The objective of this work is to review the characteristics of the disease, the diagnostic means and treatments available, as well as to discuss new therapeutic options.

In vitro modeling of endometriosis and endometriotic microenvironment - Challenges and recent advances

Endometriosis is a chronic condition with high prevalence in reproductive age women, defined as the growth of endometrial tissue outside the uterine cavity, most commonly on the pelvic peritoneum. The ectopic endometrial lesions exist in a unique microenvironment created by the interaction of epithelial, stromal, endothelial, glandular, and immune cell components, dominated by inflammatory, angiogenic, and endocrine signals. Current research is directed at understanding the complex microenvironment of the lesions and its relationship with different endometriosis stages, phenotypes, and disease symptoms and at the development of novel diagnostic and therapeutic concepts that minimalize the undesirable side effects of current medical management. Recreating pathophysiological cellular and molecular mechanisms and identifying clinically relevant metrics to assess drug efficacy is a great challenge for the experimental disease models. This review summarizes the complete range of available in vitro experimental systems used in endometriotic studies, which reflect the multifactorial nature of the endometriotic lesion. The article discusses the simplistic in vitro models such as primary endometrial cells and endometriotic cell lines to heterogeneous 2D co-cultures, and recently more common, 3D systems based on self-organization and controlled assembly, both in microfluidic or bioprinting methodologies. Basic research models allow studying fundamental pathological mechanisms by which menstrual endometrium adheres, invades, and establishes lesions in ectopic sites. The advanced endometriosis experimental models address the critical challenges and unsolved problems and provide an approach to drug screening and medicine discovery by mimicking the complicated behaviors of the endometriotic lesion.

Evaluation of the relationship between miR-337-3p and RAP1A gene in endometriosis

Background:

Endometriosis, a prevalent multifactorial condition, has a different effect on mental and physical health in women. MicroRNAs have been reported as a main epigenetic factor in endometriosis pathogenesis. However, the role of miR-337-3p and its direct target gene, RAP1A, in endometriosis tissues have not been investigated.

Objective:

The aim of this study was to evaluate the expression level of miR-337-3p and RAP1A gene in endometriosis tissues and normal endometrium tissues.

Materials and methods:

We measured the expression levels of miR-337-3p and RAP1A gene by quantitative polymerase chain reaction (qRT-PCR) in 15 eutopic and ectopic tissue samples of superficial peritoneal lesions from women with endometriosis and 15 normal endometrial tissue samples from women without any symptom of endometriosis.

Results:

The results showed the expression level of RAP1A gene significantly increased in endometriosis tissue samples (both of ectopic and eutopic tissues), while miR-337-3p expression level decreased significantly in these tissues compared to the normal endometrium.

Conclusion:

In this study, we observed an inverse relationship between miR-337-3p and RAP1A gene expression in endometriosis. Dysregulation of these genes can also be interpreted as their role in the pathogenesis and progression of endometriosis.

Diagnostic gene biomarkers for predicting immune infiltration in endometriosis

OBJECTIVE

To determine the potential diagnostic markers and extent of immune cell infiltration in endometriosis (EMS).

METHODS

Two published profiles (GSE7305 and GSE25628 datasets) were downloaded, and the candidate biomarkers were identified by support vector machine recursive feature elimination analysis and a Lasso regression model. The diagnostic value and expression levels of biomarkers in EMS were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting, then further validated in the GSE5108 dataset. CIBERSORT was used to estimate the composition pattern of immune cell components in EMS.

RESULTS

One hundred and fifty-three differential expression genes (DEGs) were identified between EMS and endometrial with 83 upregulated and 51 downregulated genes. Gene sets related to arachidonic acid metabolism, cytokine-cytokine receptor interactions, complement and coagulation cascades, chemokine signaling pathways, and systemic lupus erythematosus were differentially activated in EMS compared with endometrial samples. Aquaporin 1 (AQP1) and ZW10 binding protein (ZWINT) were identified as diagnostic markers of EMS, which were verified using qRT-PCR and western blotting and validated in the GSE5108 dataset. Immune cell infiltrate analysis showed that AQP1 and ZWINT were correlated with M2 macrophages, NK cells, activated dendritic cells, T follicular helper cells, regulatory T cells, memory B cells, activated mast cells, and plasma cells.

CONCLUSION

AQP1 and ZWINT could be regarded as diagnostic markers of EMS and may provide a new direction for the study of EMS pathogenesis in the future.

Environmental Exposure to Non-Persistent Endocrine Disrupting Chemicals and Endometriosis: A Systematic Review

Endometriosis is a disease characterized by the presence of the uterine endometrium outside of its normal location. As the etiology of endometriosis is not well known and hormonal imbalance is central to disease pathogenesis, the potential contribution of exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized in endometriosis. A systematic search of the literature was carried out to identify relevant studies using: PubMed, Scopus, Elsevier, Springer; EBSCO, and Web of Science. A total of 22 studies were considered. Most of the studies reviewed in this paper showed an association between exposure to BPA and phthalates and endometriosis. In the case of phthalate exposure, the reviewed studies found an association between the concentration of at least one phthalate metabolite and endometriosis. Only one study was performed to assess the exposure to parabens and a significant relationship with endometriosis was found. Additionally, only one study assessed the relationship of non-persistent pesticide exposure with endometriosis, observing a significant association between endometriosis and the urinary concentration of diazinon, chlorpyrifos, and chlorpyrifos-methyl. Studies struggled to provide a conclusion on the effect of exposure to benzophenones on endometriosis. Despite the numerous limitations of the results, the reviewed studies suggest that exposure to non-persistent endocrine disruptors, especially bisphenol A and phthalates may affect endometriosis. The results of the studies on exposure to parabens, benzophenones, and non-persistent insecticides are inconclusive.

Inhibition of Neutrophil Extracellular Traps Formation by Cl-Amidine Alleviates Lipopolysaccharide-Induced Endometritis and Uterine Tissue Damage

Endometritis is a common disease that affects the production in dairy cows and leads to severe losses in the dairy industry. Neutrophil extracellular traps (NETs) formation promotes pathogenic invasions of the lumen of the tissue, leading to inflammatory diseases such as mastitis, pancreatitis, and septic infection. However, research that could show the relationship between NETs and endometritis is scarce. Cl-amidine has been shown to ameliorate the disease squealing and clinical manifestation in various disease models. In this study, we investigated the role of NETs in LPS-triggered endometritis in rats and evaluated the therapeutic efficiency of Cl-amidine. An LPS-induced endometritis model in rats was established and found that the formation of NETs can be detected in the rat's uterine tissues in vivo. In addition, Cl-amidine treatment can inhibit NETs construction in LPS-induced endometritis in rats. Myeloperoxidase (MPO) activity assay indicated that Cl-amidine treatment remarkably alleviated the inflammatory cell infiltrations and attenuated the damage to the uterine tissue. The Western blot results indicated that Cl-amidine decreased the expression of citrullinated Histone H3 (Cit-H3) and high-mobility group box 1 protein (HMGB1) protein in LPS-induced rat endometritis. The ELISA test indicated that Cl-amidine treatment significantly inhibited the expression of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. The NETs were determined by Quant-iTTMPicoGreen dsDNA kit®, which indicated that Cl-amidine significantly inhibited the NETs in rat serum. All results showed that Cl-amidine effectively reduced the expression of Cit-H3 and HMGB1 proteins by inhibiting the formation of NETs, thereby attenuating the inflammatory response to LPS-induced endometritis in rats. Hence, Cl-amidine could be a potential candidate for the treatment of endometritis.

Down-regulating HK2 inhibits proliferation of endometrial stromal cells through a noncanonical pathway involving phosphorylation of STAT1 in endometriosis

BACKGROUND

Endometriosis is a benign gynecologic disease that causes chronic pelvic pain, dysmenorrhea and infertility and shares several characteristics with malignant tumors, afflicting women of reproductive age. Hexokinase 2 (HK2) plays an essential role as the first rate-limiting enzyme in the metabolic glycolysis pathway, and its abnormal elevation in tumors is associated with tumor genesis and metastasis. However, the expression and role of HK2 in endometriosis remain unclear.

METHODS

We sequenced the primary endometrial stromal cells from patients with endometrioma and utilized immunohistochemistry, quantitative real-time PCR and western blot to determine the expression of HK2. Then wound healing assays, cell invasion assays, cell proliferation assays were performed to explore the functions of HK2 in endometrial stromal cells. Furthermore, mice models of endometriosis were used to observe the effects of HK2 inhibitors in vivo. Lastly, glycolysis metabolism detection and transcriptome sequencing were carried out in HK2-knockdown endometrial stromal cells to analyze the mechanism of HK2 affecting cell function.

RESULTS

Endometrial stromal cells of endometrioma displayed active glycolysis metabolism and elevated expression of HK2. Downregulating HK2 reduced the migration, invasion and proliferation capacity of endometrial stromal cells. Knockdown of HK2 induced upregulation of signal transducer and activator of transcription 1 (STAT1) and their phosphorylation to attenuate the proliferation of endometrial stromal cells.

CONCLUSIONS

HK2 is associated with the migration, invasion and proliferation of endometrial stromal cells, which might provide new insights into the pathogenesis and treatment of endometriosis.

Comprehensive Analysis of RNA-Seq in Endometriosis Reveals Competing Endogenous RNA Network Composed of circRNA, lncRNA and mRNA

Although long non coding RNAs (lncRNAs) and circular RNAs (circRNAs) play important roles in the pathogenesis of diseases, endometriosis related lncRNAs and circRNAs are still rarely reported. This study focused on the potential molecular mechanism of endometriosis related competitive endogenous RNA (ceRNA) composed of lncRNAs and circRNAs. We performed high-throughout sequencing of six normal endometria, six eutopic endometria and six ectopic endometria for the first time to describe and analyze the expression profile of lncRNA, circRNA and mRNA. Our results showed that 140 lncRNAs, 107 circRNAs and 1,206 mRNAs were differentially expressed in the ectopic group, compared with the normal and eutopic groups. We established an lncRNA/circRNA-mRNA co-expression network using pearson correlation test. Meanwhile, the results of Gene set enrichment analysis analysis showed that the 569 up-regulated differentially expressed mRNA (DEmRNA) were mainly related to the epithelial-mesenchymal transition, regulation of immune system process and immune effector process. Subsequently, we established a DElncRNA-miRNA and DEcircRNA-miRNA network using the starbase database, identified the common miRNAs and constructed DElncRNA/DEcircRNA-miRNA pairs. miRDB, Targetscan, miRwalk and circRNA/lncRNA-mRNA pairs jointly determined the miRNA-mRNA portion of the circRNA/lncRNA-miRNA-mRNA co-expression network. RT-qPCR results of 15 control samples and 25 ectopic samples confirmed that circGLIS2, circFN1, LINC02381, IGFL2-AS1, CD84, LYPD1 and FAM163A were significantly overexpressed in ectopic tissues. In conclusion, this is the first study to illustrate ceRNA composed of differentially expressed circRNA, lncRNA and mRNA in endometriosis. We also found that lncRNA and circRNA exerted a pivotal function on the pathogenesis of endometriosis, which can provide new insights for further exploring the pathogenesis of endometriosis and identifying new targets.

The roles of interleukin-1 receptor accessory protein in certain inflammatory conditions

Interleukin-1 receptor accessory protein (IL-1RAcP) is a member of the immunoglobulin superfamily proteins consisting of soluble and membranous isoforms. IL-1RAcP plays an essential role in the signaling of the IL-1 family cytokines such as IL-1, IL-33, and IL-36, as well as tyrosine kinases FLT3 and C-Kit. IL-1RAcP generally initiate inflammatory signaling pathway through the recruitment of signaling mediators, including MYD88 and IRAK. Chronic inflammation following prolonged signaling of cytokine receptors is a critical process in the pathogenesis of many inflammatory disorders, including autoimmunity, obesity, psoriasis, type 1 diabetes, endometriosis, preeclampsia and Alzheimer's disease. Recently IL-1RAcP aberrant signaling has been considered to play a central role in the pathogenesis of these chronic inflammatory diseases. Targeting IL-1RAcP signaling pathway that was recently considered in clinical trials related to malignancies, also indicates its potential as therapeutic target for the inflammatory and autoimmune diseases. This review summarizes the molecular structure, components associated with IL-1RAcP signaling pathways, and their involvement in the pathogenesis of different inflammatory diseases. We will also discuss the effect of IL-1RAcP inhibition for treatment proposes.

Altered p16Ink4a, IL-1β, and Lamin b1 Protein Expression Suggest Cellular Senescence in Deep Endometriotic Lesions

Endometriosis causes immunological and cellular alterations. Endometriosis lesions have lower levels of lamin b1 than the endometrium. Moreover, high levels of pro-inflammatory markers are observed in the peritoneal fluid, follicular fluid, and serum in endometriosis lesions. Thus, we hypothesized that the accumulation of senescent cells in endometriosis tissues would facilitate endometriosis maintenance in an inflammatory microenvironment. To study senescent cell markers and the senescence-associated secretory phenotype (SASP) in endometriosis lesions, we conducted a cross-sectional study with 27 patients undergoing video laparoscopy for endometriosis resection and 19 patients without endometriosis. Endometriosis lesions were collected from patients with endometriosis, while eutopic endometrium was collected from patients both with and without endometriosis. Tissues were evaluated for senescence markers (p16Ink4a, lamin b1, and IL-1β) and interleukin concentrations. The expression of p16Ink4a increased in lesions compared to that in eutopic endometrium from endometriosis patients in the secretory phase. In the proliferative phase, lesions exhibited lower lamin b1 expression but higher IL-4 expression than the eutopic endometrium. Further, IL-1β levels were higher in the lesions than in the eutopic endometrium in both the secretory and proliferative phases. We believe that our findings may provide targets for better therapeutic interventions to alleviate the symptoms of endometriosis.

Progesterone Actions and Resistance in Gynecological Disorders

Estrogen and progesterone and their signaling mechanisms are tightly regulated to maintain a normal menstrual cycle and to support a successful pregnancy. The imbalance of estrogen and progesterone disrupts their complex regulatory mechanisms, leading to estrogen dominance and progesterone resistance. Gynecological diseases are heavily associated with dysregulated steroid hormones and can induce chronic pelvic pain, dysmenorrhea, dyspareunia, heavy bleeding, and infertility, which substantially impact the quality of women's lives. Because the menstrual cycle repeatably occurs during reproductive ages with dynamic changes and remodeling of reproductive-related tissues, these alterations can accumulate and induce chronic and recurrent conditions. This review focuses on faulty progesterone signaling mechanisms and cellular responses to progesterone in endometriosis, adenomyosis, leiomyoma (uterine fibroids), polycystic ovary syndrome (PCOS), and endometrial hyperplasia. We also summarize the association with gene mutations and steroid hormone regulation in disease progression as well as current hormonal therapies and the clinical consequences of progesterone resistance.

The Eutopic Endometrium Proteome in Endometriosis Reveals Candidate Markers and Molecular Mechanisms of Physiopathology

Endometriosis is a common chronic gynaecological disease causing various symptoms, such as infertility and chronic pain. The gold standard for its diagnosis is still laparoscopy and the biopsy of endometriotic lesions. Here, we aimed to compare the eutopic endometrium from women with or without endometriosis to identify proteins that may be considered as potential biomarker candidates. Eutopic endometrium was collected from patients with endometriosis (n = 4) and women without endometriosis (n = 5) during a laparoscopy surgery during the mid-secretory phase of their menstrual cycle. Total proteins from tissues were extracted and digested before LC-MS-MS analysis. Among the 5301 proteins identified, 543 were differentially expressed and enriched in two specific KEGG pathways: focal adhesion and PI3K/AKT signaling. Integration of our data with a large-scale proteomics dataset allowed us to highlight 11 proteins that share the same trend of dysregulation in eutopic endometrium, regardless of the phase of the menstrual cycle. Our results constitute the first step towards the identification of potential promising endometrial diagnostic biomarkers. They provide new insights into the mechanisms underlying endometriosis and its etiology. Our results await further confirmation on a larger sample cohort.

Effects of endometriosis on immunity and mucosal microbial community dynamics in female olive baboons

Endometriosis is defined as the growth of endometrial tissue in ectopic locations, and is associated with altered immune and microbial phenotypes. It is unclear if these changes are the result of the disease or may be causative. We induced endometriosis in non-human primates (Papio Anubis) to test our hypothesis that the growth of endometriotic lesions results in alterations in immune and microbial dynamics that may advance disease progression. Baboon samples were collected pre-inoculation (prior to disease induction), at 3, 6, 9, and 15 months after disease induction. Tolerant regulatory T-cells (Tregs) and inflammatory T-helper 17 (Th17) cells were identified in peripheral blood and within the eutopic/ectopic endometrial tissues. Microbiome communities were identified in fecal/urine samples. The induction of endometriosis decreased peripheral Tregs cells while Th17 cells increased at all post-induction collections, thus reducing the Tregs:Th17 cells ratio, indicating systemic inflammation. Microbiome diversity and abundance were altered at each sample site after disease induction. Thus, induction of endometriosis in baboons caused an immune shift toward an inflammatory profile and altered mucosal microbial profiles, which may drive inflammation through production of inflammatory mediators. Immune and microbial profiling may lead to innovative diagnostic tools and novel therapies for endometriosis treatment.

MiodesinTM Positively Modulates the Immune Response in Endometrial and Vaginal Cells

Endometriosis presents high prevalence and its physiopathology involves hyperactivation of endometrial and vaginal cells, especially by bacteria. The disease has no cure and therapies aiming to inhibit its development are highly desirable. Therefore, this study investigated whether Miodesin^TM (10 µg/mL = IC₈₀; 200 µg/mL = IC₅₀), a natural compound constituted by Uncaria tomentosa, Endopleura uchi, and astaxanthin, could exert anti-inflammatory and anti-proliferative effects against Lipopolysaccharides (LPS) stimulation in endometrial and Candida albicans vaginal cell lines. VK2 E6/E7 (vaginal) and KLE (epithelial) cell lines were stimulated with Candida albicans (1 × 10⁷ to 5 × 10⁷/mL) and LPS (1 μg/mL), respectively. Miodesin^TM inhibited mRNA expression for Nuclear factor kappa B (NF-κB), ciclo-oxigenase 1 (COX-1), and phospholipase A2 (PLA2), beyond the C–C motif chemokine ligand 2 (CCL2), CCL3, and CCL5 in VK2 E6/E7 cells (p < 0.05). In addition, the inhibitory effects of both doses of Miodesin^TM (10 µg/mL and 200 µg/mL) resulted in reduced secretion of interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor α (TNF-α) (24 h, 48 h, and 72 h) and CCL2, CCL3, and CLL5 (p < 0.05) by VK2 E6/E7 cells. In the same way, COX-1 Miodesin^TM inhibited LPS-induced hyperactivation of KLE cells, as demonstrated by reduced secretion of IL-1β, IL-6, IL-8, TNF-α (24 h, 48 h, and 72 h) and CCL2, CCL3, and CLL5 (p < 0.05). Furthermore, Miodesin^TM also inhibited mRNA expression and secretion of matrix metalloproteinase-2 (MMP-2), MMP-9, and vascular endothelial growth factor (VEGF), which are key regulators of invasion of endometrial cells. Thus, the study concludes that Miodesin^TM presents beneficial effects in the context of endometriosis, positively affecting the inflammatory and proliferative response.

Endometriosis, Psoriasis, and Psoriatic Arthritis: A Prospective Cohort Study

Endometriosis, psoriasis, and psoriatic arthritis (PsA) are chronic inflammatory disorders whose etiologies remain poorly understood but may be correlated, as endometriosis has been associated with other inflammatory disorders. We investigated the bidirectional associations between laparoscopically confirmed endometriosis and physician-diagnosed psoriasis and PsA in the Nurses' Health Study II cohort (n = 116,429, United States, 1991-2013). We confirmed 4,112 incident cases of laparoscopically confirmed endometriosis (mean age at diagnosis = 40.3 years) and 697 validated physician-diagnosed cases of psoriasis (mean age at diagnosis = 43.6 years), 110 of which presented with concomitant PsA. A history of psoriasis with concomitant PsA was associated with a 2-fold higher risk of endometriosis (hazard ratio (HR) = 2.01, 95% CI: 1.23, 3.30); however, no association was observed between psoriasis without PsA and endometriosis risk (HR = 0.93, 95% CI: 0.68, 1.26). When endometriosis was the exposure, it was not associated with a risk of subsequent psoriasis (HR = 1.28, 95% CI: 0.95, 1.72). The risk of psoriasis with PsA was notably higher; however, the sample size was small and the confidence intervals wide (HR = 1.77, 95% CI: 0.89, 3.52). Our findings suggest that psoriasis with concomitant PsA is associated with greater risk of laparoscopically confirmed endometriosis. In addition, there was a suggestive association between endometriosis diagnosis and subsequent risk of psoriasis with PsA.

Endometriosis and cardiovascular disease

Endometriosis is a chronic gynaecological disease affecting 1 in 10 reproductive-age women. It is defined as the presence of endometrium-like tissue outside the uterus. Beyond this placid anatomical definition, endometriosis is a complex, hormonal, inflammatory, and systemic condition that poses significant familial, psychological, and economic burden. The interaction between the cardiovascular system and endometriosis has become a field of interest as the underlying mutual mechanisms become better understood. On the basis of accumulating fundamental and clinical evidence, it is likely that there exists a close relationship between endometriosis and the cardiovascular system. Therefore, investigating the endometriosis-cardiovascular interaction is highly clinically significant. In this review, we highlight our current understanding of the pathophysiology of endometriosis with systemic hormonal, pro-inflammatory, pro-angiogenic, immunologic, and genetic processes beyond the peritoneal microenvironment. Additionally, we provide current clinical evidence about how endometriosis interacts with cardiovascular risk factors and cardiovascular disease (CVD). To date, only small associations between endometriosis and CVD have been reported in observational studies, inherently limited by the potential influence of unmeasured confounding. Cardiovascular disease in women with endometriosis remains understudied, under-recognized, and underdiagnosed. More detailed study of the cardiovascular-endometriosis interaction is needed to fully understand its clinical relevance, underlying pathophysiology, possible means of early diagnosis and prevention.

Microbiome analysis in women with endometriosis: Does a microbiome exist in peritoneal fluid and ovarian cystic fluid?

Purpose

To investigate the relationship between the microbiome of the female genital tract and endometriosis.

Methods

This prospective cohort study included 36 women who underwent laparoscopic surgery for ovarian tumor from July 2019 to April 2020. Of them, 18 had endometriosis, and 18 did not have endometriosis. Vaginal secretions, endometrial fluid, peritoneal fluid, and ovarian cystic fluid were collected during surgery. Next-generation sequencing of bacterial 16S rRNA was performed to characterize the microbiome.

Results

Specific microbiomes were not detected in either peritoneal fluid or ovarian cystic fluid regardless of the presence or absence of endometriosis and the type of cyst. When the cutoff value of infectious bacterial abundance in the vagina was set as 64.3%, there were many cases more than a cutoff value in the endometriosis group significantly (p = 0.01). When the cutoff value of infectious bacterial abundance in the endometrium was set as 18.6%, there were many cases more than a cutoff level in the endometriosis cases significantly (p = 0.02).

Conclusion

Peritoneal fluid and ovarian cystic fluid are almost sterile, although dysbiosis may occur in the vaginal and endometrial microbiome in women with endometriosis.