Molecular network analysis of endometriosis reveals a role for c-Jun-regulated macrophage activation

Analysis of inflammatory biomarkers IL-6, vascular endothelial growth factor and matrix metalloproteinases-9 expression in endometriosis

Objective

Special attention has been paid to genetic mechanisms that might have a significant impact on the context of the risk of developing endometriosis, in recent years. The study aimed to analyze the expression levels of three inflammatory biomarkers Interleukin-6 (IL-6), vascular endothelial growth factor, and matrix metalloproteinases-9, in the increased incidence of endometriosis.

Methods

The material for genetic testing was tissue slices embedded in paraffin blocks from these patients with endometriosis (I-II) (n = 24), endometriosis (III-IV) (n = 24), and the control group (n = 30) in Lianyungang maternal and child health hospital from January 2020 to December 2023. The expression levels of IL-6, vascular endothelial growth factor, and matrix metalloproteinases-9 genes were determined by the real-time polymerase chain reaction technique.

Results

The expression levels of IL-6 and vascular endothelial growth factor gene in the peripheral blood and peritoneal fluid of these endometriosis patients were not statistically significant lower than in the control group. Besides, the significant differences were found in IL-6, vascular endothelial growth factor and matrix metalloproteinases-9 between eutopic endometrial tissues of the endometriosis group, compared to the control group; and these increased significantly with the severity of the disease. In addition, there was significant difference in the expression level of matrix metalloproteinases-9 in peripheral blood and peritoneal fluid, and the difference was statistically significant in these patients with stages III-IV, compared with these patients with stages I-II. Among them, the Revised American Society for Reproductive Medicine classification of endometriosis was used in the group of patients with endometriosis.

Conclusion

These patients with endometriosis showed the significant differences in matrix metalloproteinases-9 expression in peripheral blood, peritoneal fluid, and eutopic and ectopic endometrial tissues as the condition worsens. The research suggested that the determination of matrix metalloproteinases-9 in peripheral blood has certain value in evaluating the condition of endometriosis, which might play an important role in the pathogenesis of endometriosis and be explored for postoperative recurrence monitoring.

Evaluation of serum and peritoneal fluid mannose-binding lectin associated serine protease-3, adipsin, properdin, and complement factor-H levels in endometriosis patients

OBJECTIVE

Endometriosis is a chronic disease which has been reported to be associated with distorted immune mechanisms. The alternative pathway is a complement system which plays a role in immune defense. The present study aimed to evaluate whether the level of alternative complement molecules differ in women with endometriosis compared to heathy individuals.

METHODS

A total of 58 women participated in this prospective research. Women with a diagnosis of endometriosis confirmed by laparoscopy (n = 32) were compared to healthy women (n = 26) in terms of serum adipsin, properdin, mannose-binding lectin-associated serine protease-3 and complement factor-H (CFH) levels. The peritoneal fluid samples which were taken during the endometriosis surgery were also analyzed in terms of the complement levels. The clinical and demographic data including the serum CA-125 level and pelvic pain were also analyzed. SPSS version 23.0 was used in statistical analysis.

RESULTS

The serum levels of adipsin and CFH were found to be significantly increased in women with endometriosis (P = 0.027 and P = 0.040, respectively). Serum adipsin level was found to significantly correlate with serum CA-125 level (r = 0.320, P = 0.015), serum CFH level (r = 0.705, P < 0.001), and degree of the pelvic pain complaint (r = 0.326, P = 0.013). A strong, positive correlation was also observed between peritoneal fluid levels of adipsin, and CFH (r = 0.593; P < 0.001).

CONCLUSION

To the best of our knowledge, the present study is the first to evaluate the alternative complement system in women with endometriosis. The current findings may be noteworthy to elucidate the possible role of the key molecules of the alternative pathway in endometriosis pathogenesis.

The correlation between immune cells and endometriosis: a bidirectional two-sample mendelian randomization study

OBJECTIVES

Endometriosis (EM), a prevalent estrogen-dependent inflammatory disorder affecting women of reproductive age, is characterized by the presence of endometrial-like tissue outside the uterus, resulting in pelvic scarring, pain, and infertility. Although the pathogenesis of EM remains poorly understood, there is growing evidence suggesting the involvement of the immune system in its etiology, pathophysiology, and associated morbidities such as pain, infertility, and adverse pregnancy outcomes. While previous studies have indicated a close relationship between the immune system and EM, the specific underlying mechanism remains incompletely elucidated.

METHODS

Through the utilization of publicly available genetic data, a two-sample Mendelian randomization (MR) analysis was conducted to establish an association between 731 immune cell phenotypes and EM. Comprehensive sensitivity analyses were performed to validate the robustness, heterogeneity, and potential horizontal pleiotropy of the findings.

RESULTS

The MR analysis revealed potential associations between 22 immune cell phenotypes and EM. Conversely, reverse MR analysis identified 11 immune phenotypes demonstrating potential associations between genetic liability in the immune phenotypes and EM.

CONCLUSION

This study provides evidence of a potential correlation between immune cell phenotypes and EM, including the existence of reverse causation. These findings open up new avenues for investigating the underlying mechanisms of EM.

The role and potential treatment of macrophages in patients with infertility and endometriosis

Endometriosis is characterized as a macrophage-related ailment due to its strong link with immune dysfunction. Understanding the status of macrophage polarization in the context of endometriosis-related infertility is crucial for advancing diagnostic and therapeutic strategies. Our comprehensive review delves into the foundational understanding of macrophages and their profound influence on both endometriosis and infertility. Additionally, we illuminate the complex role of macrophages in infertility and endometriosis specifically. Finally, we focused on four critical dimensions: follicular fluid, the intraperitoneal environment, endometrial receptivity, and strategies for managing endometriosis. It is clear that throughout the progression of endometriosis, the diverse polarization states of macrophages play a pivotal role in the internal reproductive environment of infertile individuals grappling with this condition. Modulating macrophage polarization in the reproductive environment of endometriosis patients could address infertility challenges more effectively, offering a promising pathway for treating infertility associated with endometriosis.

Eutopic and Ectopic Endometrial Interleukin-17 and Interleukin-17 Receptor Expression at the Endometrial-Myometrial Interface in Women with Adenomyosis: Possible Pathophysiology Implications

Adenomyosis involves the infiltration of endometrial glands and stroma deep into the uterine tissue, causing disruption to the endometrial-myometrial interface (EMI). The role of interleukin-17 (IL-17) has been extensively studied in endometriosis, but its involvement in adenomyosis remains unclear. This study aimed to investigate the expression of IL-17 in eutopic and ectopic endometrium (adenomyosis) of individuals with adenomyosis at the level of EMI. Paired tissues of eutopic endometrium and adenomyoma were collected from 16 premenopausal women undergoing hysterectomy due to adenomyosis. The IL-17 system was demonstrated in paired tissue samples at the level of EMI by the immunochemistry study. Gene expression levels of IL-17A and IL-17 receptor (IL-17R) were assessed through quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Comparative gene transcript amounts were calculated using the delta-delta Ct method. By immunohistochemical staining, CD4, IL-17A, and IL-17R proteins were detected in both eutopic endometrium and adenomyosis at the level of EMI. IL-17A and IL-17R were expressed mainly in the glandular cells, and the expression of both IL-17A and IL-17R was found to be stronger in adenomyosis than in endometrium. 3-Diaminobenzidine (DAB) staining revealed greater IL-17A expression in adenomyosis compared to eutopic endometrium. Quantitative RT-PCR showed 7.28-fold change of IL-17A and 1.99-fold change of IL-17R, and the fold change level of both IL-17A and IL-17R is significantly higher in adenomyosis (IL-17A: p = 0.047, IL-17R: p = 0.027) versus eutopic endometrium. We found significantly higher IL-17 levels in adenomyosis compared to eutopic endometrium at the level of EMI. The results showed that the IL-17 system may play a role in adenomyosis.

The involvement of peritoneal GATA6+ macrophages in the pathogenesis of endometriosis

Endometriosis is a chronic inflammatory disease that causes debilitating pelvic pain in women. Macrophages are considered to be key players in promoting disease progression, as abundant macrophages are present in ectopic lesions and elevated in the peritoneum. In the present study, we examined the role of GATA6+ peritoneal macrophages on endometriosis-associated hyperalgesia using mice with a specific myeloid deficiency of GATA6. Lesion induction induced the disappearance of TIM4hi MHCIIlo residential macrophages and the influx of increased Ly6C+ monocytes and TIM4lo MHCIIhi macrophages. The recruitment of MHCIIhi inflammatory macrophages was extensive in Mac Gata6 KO mice due to the severe disappearance of TIM4hi MHCIIlo residential macrophages. Ki67 expression confirmed GATA6-dependent proliferative ability, showing different proliferative phenotypes of TIM4+ residential macrophages in Gata6f/f and Mac Gata6 KO mice. Peritoneal proinflammatory cytokines were elevated after lesion induction. When cytokine levels were compared between Gata6f/f and Mac Gata6 KO mice, TNFα at day 21 in Gata6f/f mice was higher than in Mac Gata6 KO mice. Lesion induction increased both abdominal and hind paw sensitivities. Gata6f/f mice tended to show higher sensitivity in the abdomen after day 21. Elevated expression of TRPV1 and CGRP was observed in the dorsal root ganglia after ELL induction in Gata6f/f mice until days 21 and 42, respectively. These results support that peritoneal GATA6+ macrophages are involved in the recruitment and reprogramming of monocyte-derived macrophages. The extensive recruitment of monocyte-derived macrophages in Mac Gata6 KO mice might protect against inflammatory stimuli during the resolution phase, whereas GATA6 deficiency did not affect lesion initiation and establishment at the acute phase of inflammation. GATA6+ residential macrophages act to sustain local inflammation in the peritoneum and sensitivities in the neurons, reflecting endometriosis-associated hyperalgesia.

Altered Monocyte and Lymphocyte Phenotypes Associated with Pathogenesis and Clinical Efficacy of Progestogen Therapy for Peritoneal Endometriosis in Adolescents

Background: Immunological imbalances characteristic of endometriosis may develop as early as the primary manifestations of the disease in adolescence. Objective: To evaluate subpopulation dynamics of monocytes and lymphocytes in peripheral blood and peritoneal fluid of adolescents with peritoneal endometriosis at diagnosis and after 1-year progestogen therapy. Methods: This study included 70 girls, 13-17 years old, diagnosed laparoscopically with peritoneal endometriosis (n = 50, main group) or paramesonephric cysts (n = 20, comparison group). Phenotypes of monocytes and lymphocytes of the blood and macrophages of the peritoneal fluid were analyzed by flow cytometry at diagnosis and during progestogen therapy. Results: Differential blood counts of CD16+ (p < 0.001) and CD86+ (p = 0.017) monocytes were identified as independent risk factors for peritoneal endometriosis in adolescents. During the treatment, cytotoxic lymphocytes CD56dimCD16bright (p = 0.049) and CD206+ monocytes (p < 0.001) significantly increased while CD163+ monocytes decreased in number (p = 0.017). The CD56dimCD16bright blood counts before (p < 0.001) and during progestogen therapy (p = 0.006), as well as CD206+ blood counts during the treatment (p = 0.038), were associated with the efficacy of pain relief after 1-year progestogen therapy. Conclusions: Adolescents with peritoneal endometriosis have altered counts of pro- and anti-inflammatory monocytes and lymphocytes both before and after 1-year progestogen therapy, correlating with treatment efficacy and justifying long-term hormonal therapy.

Cytokine and chemokine profiles in women with endometriosis, polycystic ovary syndrome, and unexplained infertility

Numerous factors (including immunological, congenital, hormonal, and morphological disorders) can lead to infertility. In this regard, 3 specific diseases associated with infertility are discussed in this review study (i.e., polycystic ovary syndrome [PCOS], endometriosis [EMS], and unexplained infertility [UI]). PCOS is a common endocrine disorder characterized by chronic low-grade inflammation, and EMS is a benign disease characterized by the presence of ectopic endometrial tissue. UI refers to couples who are unable to conceive for no known reason. Conception and pregnancy are significantly affected by the immune system; in this regard, chemokines and cytokines play important roles in the regulation of immune responses. Patients with PCOS, EMS, and UI have altered cytokine and chemokine profiles, suggesting that dysregulation of these molecules may contribute to infertility in these conditions. Accordingly, the issue of infertility is addressed in this review study, a condition that affects approximately 16% of couples worldwide.

Inhibition of CSF1R and KIT With Pexidartinib Reduces Inflammatory Signaling and Cell Viability in Endometriosis

Endometriosis is a common and debilitating disease, affecting ∼170 million women worldwide. Affected patients have limited therapeutic options such as hormonal suppression or surgical excision of the lesions, though therapies are often not completely curative. Targeting receptor tyrosine kinases (RTKs) could provide a nonhormonal treatment option for endometriosis. We determined that 2 RTKs, macrophage-colony stimulating factor 1 receptor (CSF1R) and mast/stem cell growth factor receptor KIT (KIT), are overexpressed in endometriotic lesions and could be novel nonhormonal therapeutic targets for endometriosis. The kinase activity of CSF1R and KIT is suppressed by pexidartinib, a small molecule inhibitor that was recently approved by the US Food and Drug Administration. Using immunohistochemistry, we detected CSF1R and KIT in endometriotic tissues obtained from peritoneal lesions, colorectal lesions, and endometriomas. Specifically, we show that KIT is localized to the epithelium of the lesions, while CSF1R is expressed in the stroma and macrophages of the endometriotic lesions. Given the high epithelial expression of CSF1R and KIT, 12Z endometriotic epithelial cells were used to evaluate the efficacy of dual CSF1R and KIT inhibition with pexidartinib. We found that pexidartinib suppressed activation in 12Z cells of JNK, STAT3, and AKT signaling pathways, which control key proinflammatory and survival networks within the cell. Using quantitative real-time polymerase chain reaction, we determined that pexidartinib suppressed interleukin 8 (IL8) and cyclin D1 (CCND1) expression. Lastly, we demonstrated that pexidartinib decreased cell growth and viability. Overall, these results indicate that pexidartinib-mediated CSF1R and KIT inhibition reduces proinflammatory signaling and cell viability in endometriosis.

An integrated multi-tissue approach for endometriosis candidate biomarkers: a systematic review

Biomarker identification could help in deciphering endometriosis pathophysiology in addition to their use in the development of non invasive diagnostic and prognostic approaches, that are essential to greatly improve patient care. Despite extensive efforts, no single potential biomarker or combination has been clinically validated for endometriosis.Many studies have investigated endometriosis-associated biological markers in specific tissues, but an integrative approach across tissues is lacking. The aim of this review is to propose a comprehensive overview of identified biomarkers based on tissue or biological compartment, while taking into account endometriosis phenotypes (superficial, ovarian or deep, or rASRM stages), menstrual cycle phases, treatments and symptoms.We searched PubMed and Embase databases for articles matching the following criteria: 'endometriosis' present in the title and the associated term 'biomarkers' found as Medical Subject Headings (MeSH) terms or in all fields. We restricted to publications in English and on human populations. Relevant articles published between 01 January 2005 (when endometriosis phenotypes start to be described in papers) and 01 September 2022 were critically analysed and discussed.Four hundred forty seven articles on endometriosis biomarkers that included a control group without endometriosis and provided specific information on endometriosis phenotypes are included in this review. Presence of information or adjustment controlling for menstrual cycle phase, symptoms and treatments is highlighted, and the results are further summarized by biological compartment. The 9 biological compartments studied for endometriosis biomarker research are in order of frequency: peripheral blood, eutopic endometrium, peritoneal fluid, ovaries, urine, menstrual blood, saliva, feces and cervical mucus. Adjustments of results on disease phenotypes, cycle phases, treatments and symptoms are present in 70%, 29%, 3% and 6% of selected articles, respectively. A total of 1107 biomarkers were identified in these biological compartments. Of these, 74 were found in several biological compartments by at least two independent research teams and only 4 (TNF-a, MMP-9, TIMP-1 and miR-451) are detected in at least 3 tissues with cohorts of 30 women or more.Integrative analysis is a crucial step to highlight potential pitfalls behind the lack of success in the search for clinically relevant endometriosis biomarkers, and to illuminate the physiopathology of this disease.

Endometriosis and the Role of Pro-Inflammatory and Anti-Inflammatory Cytokines in Pathophysiology: A Narrative Review of the Literature

Endometriosis is a chronic inflammatory disease, which explains the pain that such patients report. Currently, we are faced with ineffective, non-invasive diagnostic methods and treatments that come with multiple side effects and high recurrence rates for both the disease and pain. These are the reasons why we are exploring the possibility of the involvement of pro-inflammatory and anti-inflammatory molecules in the process of the appearance of endometriosis. Cytokines play an important role in the progression of endometriosis, influencing cell proliferation and differentiation. Pro-inflammatory molecules are found in intrafollicular fluid. They have an impact on the number of mature and optimal-quality oocytes. Endometriosis affects fertility, and the involvement of endometriosis in embryo transfer during in vitro fertilization (IVF) is being investigated in several studies. Furthermore, the reciprocal influence between anti-inflammatory and pro-inflammatory cytokines and their role in the pathogenesis of endometriosis has been assessed. Today, we can affirm that pro-inflammatory and anti-inflammatory cytokines play roles in survival, growth, differentiation, invasion, angiogenesis, and immune escape, which provides a perspective for approaching future clinical implications and can be used as biomarkers or therapy.

MRI Features of Pelvic Nerve Involvement in Endometriosis

Endometriosis is a common condition that mostly affects people assigned as female at birth. The most common clinical symptom of endometriosis is pain. Although the mechanism for this pain is poorly understood, in some cases, the nerves are directly involved in endometriosis. Endometriosis is a multifocal disease, and the pelvis is the most common location involved. Nerves in the pelvis can become entrapped and involved in endometriosis. Pelvic nerves are visible at pelvic MRI, especially when imaging planes and sequences are tailored for neural evaluation. In particular, high-spatial-resolution anatomic imaging including three-dimensional isotropic imaging and contrast-enhanced three-dimensional short inversion time inversion-recovery (STIR) fast spin-echo sequences are useful for nerve imaging. The most commonly involved nerves are the sciatic, obturator, femoral, pudendal, and inferior hypogastric nerves and the inferior hypogastric and lumbosacral plexuses. Although it is thought to be rare, the true incidence of nerve involvement in endometriosis is not known. Symptoms of neural involvement include pain, weakness, numbness, incontinence, and paraplegia and may be constant or cyclic (catamenial). Early diagnosis of neural involvement in endometriosis is important to prevent irreversible nerve damage and chronic sensorimotor neuropathy. Evidence of irreversible damage can also be seen at MRI, and radiologists should evaluate pelvic nerves that are commonly involved in endometriosis in their search pattern and report template to ensure that this information is incorporated into treatment planning.

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.

Report of the Assay Guidance Workshop on 3-Dimensional Tissue Models for Antiviral Drug Development

The National Center for Advancing Translational Sciences (NCATS) Assay Guidance Manual (AGM) Workshop on 3D Tissue Models for Antiviral Drug Development, held virtually on 7-8 June 2022, provided comprehensive coverage of critical concepts intended to help scientists establish robust, reproducible, and scalable 3D tissue models to study viruses with pandemic potential. This workshop was organized by NCATS, the National Institute of Allergy and Infectious Diseases, and the Bill and Melinda Gates Foundation. During the workshop, scientific experts from academia, industry, and government provided an overview of 3D tissue models' utility and limitations, use of existing 3D tissue models for antiviral drug development, practical advice, best practices, and case studies about the application of available 3D tissue models to infectious disease modeling. This report includes a summary of each workshop session as well as a discussion of perspectives and challenges related to the use of 3D tissues in antiviral drug discovery.

Influence of interleukin-8 polymorphism on endometriosis-related pelvic pain

Endometriosis presents a pro-inflammatory microenvironment influenced by cytokines, such as interleukin (IL)-8, which expression may be influenced by genetic polymorphisms. Therefore, we aimed to investigate the role of interleukin (IL)-8 rs4073 polymorphism in endometriosis' development and its related symptoms. A case-control study was conducted with 207 women with endometriosis and 193 healthy controls. Polymorphism was genotyped using a TaqMan validated assay. Associations were evaluated by binary logistic regression, using odds ratios (OR) and 95 % confidence intervals (CI), and P ≤ 0.05 was considered significant. Cases were younger (36 ± 6.8 versus 39 ± 8.4) and had lower body mass index (26.5 ± 5.3 versus 35.7 ± 6.3 Kg/m2) than controls (P < 0.001). Higher prevalence of symptoms and infertility was observed in cases, compared to controls (P < 0.001). Minor allele frequencies of IL-8 rs4073 (T) were 42.3 % and 39.9 % for cases and controls, respectively, and no associations were found between IL and 8 rs4073 polymorphism and endometriosis' prevalence or staging. However, the polymorphism was associated with chronic pelvic pain among cases (OR = 0.54; 95 %CI = 0.29-0.98). The IL-8 rs4073A > T polymorphism may contribute to lower IL-8 expression and, consequently, decrease endometriosis-related pelvic pain. These findings can support the early diagnosis of endometriosis' painful symptoms, preventing its complications, and allowing an individualized treatment.

Endometriosis in the era of precision medicine and impact on sexual and reproductive health across the lifespan and in diverse populations

Endometriosis is a common estrogen-dependent disorder wherein uterine lining tissue (endometrium) is found mainly in the pelvis where it causes inflammation, chronic pelvic pain, pain with intercourse and menses, and infertility. Recent evidence also supports a systemic inflammatory component that underlies associated co-morbidities, e.g., migraines and cardiovascular and autoimmune diseases. Genetics and environment contribute significantly to disease risk, and with the explosion of omics technologies, underlying mechanisms of symptoms are increasingly being elucidated, although novel and effective therapeutics for pain and infertility have lagged behind these advances. Moreover, there are stark disparities in diagnosis, access to care, and treatment among persons of color and transgender/nonbinary identity, socioeconomically disadvantaged populations, and adolescents, and a disturbing low awareness among health care providers, policymakers, and the lay public about endometriosis, which, if left undiagnosed and under-treated can lead to significant fibrosis, infertility, depression, and markedly diminished quality of life. This review summarizes endometriosis epidemiology, compelling evidence for its pathogenesis, mechanisms underlying its pathophysiology in the age of precision medicine, recent biomarker discovery, novel therapeutic approaches, and issues around reproductive justice for marginalized populations with this disorder spanning the past 100 years. As we enter the next revolution in health care and biomedical research, with rich molecular and clinical datasets, single-cell omics, and population-level data, endometriosis is well positioned to benefit from data-driven research leveraging computational and artificial intelligence approaches integrating data and predicting disease risk, diagnosis, response to medical and surgical therapies, and prognosis for recurrence.

A long-acting anti-IL-8 antibody improves inflammation and fibrosis in endometriosis

Current pharmacological treatments for endometriosis are limited to hormonal agents that can relieve pain but cannot cure the disease. Therefore, the development of a disease-modifying drug for endometriosis is an unmet medical need. By studying human endometriotic samples, we found that the progression of endometriosis was associated with the development of inflammation and fibrosis. In addition, IL-8 expression was highly up-regulated in endometriotic tissues and closely correlated with disease progression. We created a long-acting recycling antibody against IL-8 (AMY109) and evaluated its clinical potency. Because rodents do not produce IL-8 and do not experience menstruation, we analyzed the lesions in cynomolgus monkeys that spontaneously developed endometriosis and in a surgically induced endometriosis monkey model. Both spontaneously developed and surgically induced endometriotic lesions demonstrated pathophysiology that was highly similar to that of human endometriosis. Once-a-month subcutaneous injection of AMY109 to monkeys with surgically induced endometriosis reduced the volume of nodular lesions, lowered the Revised American Society for Reproductive Medicine score as modified for monkeys, and ameliorated fibrosis and adhesions. In addition, experiments using cells derived from human endometriosis revealed that AMY109 inhibited the recruitment of neutrophils to endometriotic lesions and the production of monocyte chemoattractant protein-1 from neutrophils. Thus, AMY109 may represent a disease-modifying therapy for patients with endometriosis.

Correlations between Gut Microbial Composition, Pathophysiological and Surgical Aspects in Endometriosis: A Review of the Literature

Background and Objectives: Endometriosis is an estrogen-dependent, inflammatory, gynecological disorder represented by the migration of endometrial tissue outside the uterus. It can manifest through gynecological and gastrointestinal (GI) signs. Given the hormonal imbalances in endometriosis and the effect of microbiota on immune dysfunction, it has been thought that the human microbiome may play a role in its pathogenesis, acting differently before and after laparotomy. The aim of this review is to establish whether there is an interaction between endometriosis and gut microbial composition. Materials and Methods: We aimed to review available literature by systematically searching five databases: PubMed, EMBASE, Scopus, Cochrane Library, and ScienceDirect. We included records describing gut microbiota in the context of endometriosis-observing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines-to recognize the presence of disease by the expression of bacterial taxa-based on 16S ribosomal RNA gene sequencing analysis. Results: Among 10 studies selected, there were four review articles and six clinical trials. The latter identified significant differences at a genus level in increased Prevotella, Blautia, and Bifidobacterium and decreased Paraprevotella, Ruminococcus, and Lachnospira (p < 0.05). In patients undergoing abdominal hysterectomy, Proteobacteria phylum increased from 34.36% before surgery to 54.04% after surgery (p < 0.05). Conclusions: Although scientific literature reports different characterizations of intestinal microbiota in endometriotic patients, further evidence is needed to develop new diagnostic-therapeutic strategies, for example, administration with probiotics before surgery.

The Role of Platelets in the Pathogenesis and Pathophysiology of Adenomyosis

Widely viewed as an enigmatic disease, adenomyosis is a common gynecological disease with bewildering pathogenesis and pathophysiology. One defining hallmark of adenomyotic lesions is cyclic bleeding as in eutopic endometrium, yet bleeding is a quintessential trademark of tissue injury, which is invariably followed by tissue repair. Consequently, adenomyotic lesions resemble wounds. Following each bleeding episode, adenomyotic lesions undergo tissue repair, and, as such, platelets are the first responder that heralds the subsequent tissue repair. This repeated tissue injury and repair (ReTIAR) would elicit several key molecular events crucial for lesional progression, eventually leading to lesional fibrosis. Platelets interact with adenomyotic cells and actively participate in these events, promoting the lesional progression and fibrogenesis. Lesional fibrosis may also be propagated into their neighboring endometrial-myometrial interface and then to eutopic endometrium, impairing endometrial repair and causing heavy menstrual bleeding. Moreover, lesional progression may result in hyperinnervation and an enlarged uterus. In this review, the role of platelets in the pathogenesis, progression, and pathophysiology is reviewed, along with the therapeutic implication. In addition, I shall demonstrate how the notion of ReTIAR provides a much needed framework to tether to and piece together many seemingly unrelated findings and how it helps to make useful predictions.

Telocytes and endometriosis

Endometriosis involving the presence and growth of glands and stroma outside the uterine cavity is a common, inflammatory, benign gynecologic disease. Nevertheless, no single theory can exactly account for the pathogenesis of endometriosis. Telocytes, a kind of novel mesenchymal cells, have been suggested to be crucial in promoting angiogenesis and increasing the activity of endometrial interstitial cells and inflammatory cells. Given above roles, telocytes may be considered as the possible pathogenesis of endometriosis. We reviewed the current literature on telocytes. The following aspects were considered: (A) the telocytes' typical characteristics, function, and morphological changes in endometriosis; (B) the potential role of telocytes in endometriosis by impacting the inflammation, invasion, and angiogenesis; (C) telocytes as the potential treatment options for endometriosis.

Gene expression analysis in endometriosis: Immunopathology insights, transcription factors and therapeutic targets

Background

Endometriosis is recognized as an estrogen-dependent inflammation disorder, estimated to affect 8%-15% of women of childbearing age. Currently, the etiology and pathogenesis of endometriosis are not completely clear. Underlying mechanism for endometriosis is still under debate and needs further exploration. The involvement of transcription factors and immune mediations may be involved in the pathophysiological process of endometriosis, but the specific mechanism remains to be explored. This study aims to investigate the underlying molecular mechanisms in endometriosis.

Methods

The gene expression profile of endometriosis was obtained from the gene expression omnibus (GEO) database. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were applied to the endometriosis GSE7305 datasets. Cibersort and MCP-counter were used to explore the immune response gene sets, immune response pathway, and immune environment. Differentially expressed genes (DEGs) were identified and screened. Common biological pathways were being investigated using the kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Transcription factors were from The Human Transcription Factors. The least absolute shrinkage and selection operator (Lasso) model identified four differential expressions of transcription factors (AEBP1, HOXB6, KLF2, and RORB). Their diagnostic value was calculated by receiver operating characteristic (ROC) curve analysis and validated in the validation cohort (GSE11691, GSE23339). By constructing the interaction network of crucial transcription factors, weighted gene coexpression network analysis (WGCNA) was used to search for key module genes. Metascape was used for enrichment analysis of essential module genes and obtained HOXB6, KLF2. The HOXB6 and KLF2 were further verified as the only two intersection genes according to Support Vector Machine Recursive Feature Elimination (SVM-RFE) and random forest models. We constructed ceRNA (lncRNA-miRNA-mRNA) networks with four potential transcription factors. Finally, we performed molecular docking for goserelin and dienogest with four transcription factors (AEBP1, HOXB6, KLF2, and RORB) to screen potential drug targets.

Results

Immune and metabolic pathways were enriched in GSVA and GSEA. In single sample gene set enrichment analysis (ssGSEA), most immune infiltrating cells, immune response gene sets, and immune response pathways are differentially expressed between endometriosis and non-endometriosis. Twenty-seven transcription factors were screened from differentially expressed genes. Most of the twenty-seven transcription factors were correlated with immune infiltrating cells, immune response gene sets and immune response pathways. Furthermore, Adipocyte enhancer binding protein 1 (AEBP1), Homeobox B6 (HOXB6), Kruppel Like Factor 2 (KLF2) and RAR Related Orphan Receptor B (RORB) were selected out from twenty-seven transcription factors. ROC analysis showed that the four genes had a high diagnostic value for endometriosis. In addition, KLF2 and HOXB6 were found to play particularly important roles in multiple modules (String, WGCNA, SVM-RFE, random forest) on the gene interaction network. Using the ceRNA network, we found that NEAT1 may regulate the expressions of AEBP1, HOXB6 and RORB, while X Inactive Specific Transcript (XIST) may control the expressions of HOXB6, RORB and KLF2. Finally, we found that goserelin and dienogest may be potential drugs to regulate AEBP1, HOXB6, KLF2 and RORB through molecular docking.

Conclusions

AEBP1, HOXB6, KLF2, and RORB may be potential biomarkers for endometriosis. Two of them, KLF2 and HOXB6, are critical molecules in the gene interaction network of endometriosis. Discovered by molecular docking, AEBP1, HOXB6, KLF2, and RORB are targets for goserelin and dienogest.

AP-1 Subunit JUNB Promotes Invasive Phenotypes in Endometriosis

Endometriosis is a disease defined by the presence of abnormal endometrium at ectopic sites, causing pain and infertility in 10% of women. Mutations in the chromatin remodeling protein ARID1A (AT-rich interactive domain-containing protein 1A) have been identified in endometriosis, particularly in the more severe deep infiltrating endometriosis and ovarian endometrioma subtypes. ARID1A has been shown to regulate chromatin at binding sites of the Activator Protein 1 (AP-1) transcription factor, and AP-1 expression has been shown in multiple endometriosis models. Here, we describe a role for AP-1 subunit JUNB in promoting invasive phenotypes in endometriosis. Through a series of knockdown experiments in the 12Z endometriosis cell line, we show that JUNB expression in endometriosis promotes the expression of epithelial-to-mesenchymal transition genes co-regulated by ARID1A including transcription factors SNAI1 and SNAI2, cell adhesion molecules ICAM1 and VCAM1, and extracellular matrix remodelers LOX and LOXL2. In highly invasive ARID1A-deficient endometriotic cells, co-knockdown of JUNB is sufficient to suppress invasion. These results suggest that AP-1 plays an important role in the progression of invasive endometriosis, and that therapeutic inhibition of AP-1 could prevent the occurrence of deep infiltrating 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.

Single-Cell Transcriptome Analysis of Radiation Pneumonitis Mice

Radiation-induced lung injury (RILI), especially radiation pneumonitis (RP), is a common clinical complication associated with thoracic radiotherapy for malignant tumors. However, the specific contributions of each cell subtype to this process are unknown. Here, we provide the single-cell pathology landscape of the RP in a mouse model by unbiased single-cell RNA-seq (scRNA-seq). We found a decline of type 2 alveolar cells in the RP lung tissue, with an expansion of macrophages, especially the Fabp4low and Spp1high subgroup, while Fabp4high macrophages were almost depleted. We observed an elevated expression of multiple mitochondrial genes in the RP group, indicating a type 2 alveolar cell (AT2) response to oxidative stress. We also calculated the enrichment of a cGAS-STING signaling pathway, which may be involved in regulating inflammatory responses and cancer progression in AT2 cells of PR mice. We delineate markers and transcriptional states, identify a type 2 alveolar cell, and uncover fundamental determinants of lung fibrosis and inflammatory response in RP lung tissue of mice.

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.

Macrophage Associated Immune Checkpoint CD47 Blocking Ameliorates Endometriosis

Peritoneal macrophages play a significant role in the progression of endometriosis (EM), but their functional differentiation is still unclear, and their phagocytic ability is weak. CD47-SIRPα and PD-L1-PD-1 are considered immune checkpoints associated with macrophage phagocytosis. A specific blockade of these two pathways had been shown to increase the phagocytic clearance of cancer cells by macrophages in most cancers. We hypothesized that targeting CD47/PD-L1 in EM could improve the phagocytosis of macrophages, thereby delaying the progression of EM. From localization to quantification, from mRNA to protein, we comprehensively evaluated the expression of CD47 and PD-L1 in EM. We demonstrated that the CD47 expression in ectopic endometrium from patients with EM was significantly increased, but PD-L1was not. We performed direct co-culture experiments of endometrial stromal cells with macrophages in vitro and in vivo to assess whether ectopic endometrial stromal cells escape macrophage phagocytosis through the CD47-SIRPα signaling pathway. The results showed that targeting CD47 increased the phagocytic capacity of macrophages. Interestingly, we also found that the reduction of CD47 expression promoted apoptosis of ESCs. In conclusion, these data suggested that targeting CD47 can effectively target ectopic endometrial stromal cells through a dual mechanism of increased phagocytosis of macrophages and induced apoptosis of ectopic endometrial stromal cells. Thus, immunotherapy based on the CD47-SIRPa signaling pathway has some potential in treating EM, but further mechanistic studies are needed to explore more effective and specific antibodies.

Molecular Mechanisms Underlying the Association between Endometriosis and Ectopic Pregnancy

Endometriosis is a common inflammatory disease characterized by the presence of endometrial cells outside the uterine cavity. It is estimated that it affects 10% of women of reproductive age. Its pathogenesis covers a wide range of abnormalities, including adhesion, proliferation, and cell signaling disturbances. It is associated with a significant deterioration in quality of life as a result of chronic pelvic pain and may also lead to infertility. One of the most serious complications of endometriosis is an ectopic pregnancy (EP). Currently, the exact mechanism explaining this phenomenon is unknown; therefore, there are no effective methods of prevention. It is assumed that the pathogenesis of EP is influenced by abnormalities in the contraction of the fallopian tube muscles, the mobility of the cilia, and in the fallopian microenvironment. Endometriosis can disrupt function on all three levels and thus contribute to the implantation of the embryo beyond the physiological site. This review takes into account aspects of the molecular mechanisms involved in the pathophysiology of endometriosis and EP, with particular emphasis on the similarities between them.

Post-acute sequelae of COVID-19: A metabolic perspective

The SARS-CoV-2 pandemic continues to rage around the world. At the same time, despite strong public health measures and high vaccination rates in some countries, a post-COVID-19 syndrome has emerged which lacks a clear definition, prevalence, or etiology. However, fatigue, dyspnea, brain fog, and lack of smell and/or taste are often characteristic of patients with this syndrome. These are evident more than a month after infection, and are labeled as Post-Acute Sequelae of CoV-2 (PASC) or commonly referred to as long-COVID. Metabolic dysfunction (i.e., obesity, insulin resistance, and diabetes mellitus) is a predisposing risk factor for severe acute COVID-19, and there is emerging evidence that this factor plus a chronic inflammatory state may predispose to PASC. In this article, we explore the potential pathogenic metabolic mechanisms that could underly both severe acute COVID-19 and PASC, and then consider how these might be targeted for future therapeutic approaches.

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.

Computational Models for Diagnosing and Treating Endometriosis

Endometriosis is a common but poorly understood disease. Symptoms can begin early in adolescence, with menarche, and can be debilitating. Despite this, people often suffer several years before being correctly diagnosed and adequately treated. Endometriosis involves the inappropriate growth of endometrial-like tissue (including epithelial cells, stromal fibroblasts, vascular cells, and immune cells) outside of the uterus. Computational models can aid in understanding the mechanisms by which immune, hormone, and vascular disruptions manifest in endometriosis and complicate treatment. In this review, we illustrate how three computational modeling approaches (regression, pharmacokinetics/pharmacodynamics, and quantitative systems pharmacology) have been used to improve the diagnosis and treatment of endometriosis. As we explore these approaches and their differing detail of biological mechanisms, we consider how each approach can answer different questions about endometriosis. We summarize the mathematics involved, and we use published examples of each approach to compare how researchers: (1) shape the scope of each model, (2) incorporate experimental and clinical data, and (3) generate clinically useful predictions and insight. Lastly, we discuss the benefits and limitations of each modeling approach and how we can combine these approaches to further understand, diagnose, and treat endometriosis.

IL-33 activates group 2 innate lymphoid cell expansion and modulates endometriosis

Chronic inflammation and localized alterations in immune cell function are suspected to contribute to the progression of endometriosis and its associated symptoms. In particular, the alarmin IL-33 is elevated in the plasma, peritoneal fluid, and endometriotic lesions from patients with endometriosis; however, the exact role of IL-33 in the pathophysiology of endometriosis is not well understood. In this study, we demonstrate, in both humans and a murine model, that IL-33 contributes to the expansion of group 2 innate lymphoid cells (ILC2s), and this IL-33-induced ILC2 expansion modulates the endometriosis lesion microenvironment. Importantly, we show that IL-33 drives hallmarks of severe endometriosis, including elevated inflammation, lesion proliferation, and fibrosis, and that this IL-33-induced aggravation is mediated by ILC2s. Finally, we demonstrate the functionality of IL-33 neutralization as a promising and potentially novel therapeutic avenue for treating the debilitating symptoms of endometriosis.

The role of peripheral nerve signaling in endometriosis

A hallmark of endometriosis - a chronic debilitating condition whose causes are poorly understood - is neuronal innervation of lesions. Recent evidence demonstrates that the peripheral nervous system plays an important role in the pathophysiology of this disease. Sensory nerves, which surround and innervate endometriotic lesions, not only drive the chronic and debilitating pain associated with endometriosis but also contribute to a pro-growth phenotype by secreting neurotrophic factors and interacting with surrounding immune cells. The diverse array of contributions that neurons play in endometriosis indicate that it should be considered as a nerve-centric disease. This review is focused on the emerging field of exoneural biology and how it applies to the field of endometriosis, in particular the role that peripheral nerves play in driving and maintaining endometriotic lesions. A better understanding of the mechanisms of neuronal contribution to endometriosis, as well as their interactions with accompanying stromal and immune cells, will unearth novel disease-relevant pathways and targets, providing additional, more selective therapeutic horizons.

Metabolite profiles in the peritoneal cavity of endometriosis patients and mouse models

RESEARCH QUESTION

Which metabolites are altered in the peritoneal cavity of women with endometriosis? Could the mouse endometriosis model simulate these alterations?

DESIGN

Thirteen women with endometriosis and seven women with other benign gynaecological diseases, who underwent laparoscopic surgery, were included in this study. None had received hormonal therapy for 3 months before surgery. For the animal experiments, six and five mice were included in the endometriosis and control groups, respectively. Peritoneal fluid from the patients and peritoneal lavage fluid from the mice was collected and analysed. Non-targeted metabolomics via liquid chromatography with tandem mass spectrometry was used to identify the altered metabolites in the peritoneal fluid of endometriosis patients and mouse models. MetaboAnalyst 4.0 was used to visualize the data.

RESULTS

Several metabolites in the peritoneal cavity were significantly altered in both humans and mice with endometriosis. Concentrations of lysophosphatidylcholine (LysopC) (P=0.017 in patients and P=0.041 in the mouse model) and derivatives of phosphoethanolamine (1-arachidonoyl-sn-glycero-3-phosphoethanolamine in patients, P=0.027; 1-oleoyl-sn-glycero-3-phosphoethanolamine in patients, P=0.0086; and phosphorylethanolamine in the mouse model, P=0.0027) were significantly up-regulated in both, whereas concentrations of acylcarnitines (l-palmitoylcarnitine, P=0.047; and stearoylcarnitine, P=0.029) and kynurenine (P=0.045) were significantly increased only in humans. The human and mouse samples shared three altered enriched metabolite sets.

CONCLUSIONS

Women with endometriosis show an altered metabolic state in the abdominal cavity. The endometriosis mouse model shared half of the significantly altered metabolite sets found in the abdominal cavity of humans.

A History of Endometriosis Is Associated With Decreased Peripheral NK Cytotoxicity and Increased Infiltration of Uterine CD68+ Macrophages

Women with endometriosis may have a defective immune system. However, evidence of the immune responses of endometriosis patients with a history of endometriosis surgery is lacking, and the association between the location of endometriosis lesions and immune responses is unclear. This retrospective study included 117 females with reproductive failure and a history of endometriosis and 200 females with reproductive failure but without endometriosis to analyze their endometrial and peripheral immune responses. The results show that endometriosis was associated with decreased peripheral natural killer (NK) cytotoxicity and increased uterine macrophages. Peripheral NK cytotoxicity at effector-to-target ratios of 25:1 and 50:1 was significantly reduced in women with a history of endometriosis from that of the control group (26.6% versus 33.3% and 36.1% versus 43.3%, respectively, both P < 0.001). Furthermore, after further division of patients into three subgroups according to the location of endometriosis lesions, we observed that NK cytotoxicity in the endometriosis subgroups, especially the mixed endometriosis group, was strongly decreased from that of the controls (P = 0.001). The endometrial CD68⁺ macrophage proportion in the mixed endometriosis subgroup was higher than that in the control group (2.8% versus 2.1%, P = 0.043). In addition, the baseline estradiol (E2) level was weakly correlated with the percentage of endometrial macrophages (r = 0.251, P = 0.009), indicating a potential association among the endocrine system, endometrial immune environment, and endometriosis. This study indicated that peripheral NK cytotoxicity and endometrial immune cell profiles could be useful for diagnosing and treating endometriosis and endometriosis-related reproductive diseases.

Identification and Exploration of Novel Macrophage M2-Related Biomarkers and Potential Therapeutic Agents in Endometriosis

Endometriosis (EM) is a chronic neuroinflammatory disorder that is associated with pain and infertility that affects ∼10% of reproductive-age women. The pathophysiology and etiology of EM remain poorly understood, and diagnostic delays are common. Exploration of the underlying molecular mechanism, as well as novel diagnostic biomarkers and therapeutic targets, is urgently needed. Inflammation is known to play a key role in the development of lesions, which are a defining feature of the disorder. In our research, the CIBERSORT and WGCNA algorithms were used to establish a weighted gene co-expression network and to identify macrophage-related hub genes using data downloaded from the GEO database (GSE11691, 7305). The analysis identified 1,157 differentially expressed genes (DEGs) in EM lesions, of which five were identified as being related to M2 macrophages and were validated as differentially expressed by qRT-PCR and immunohistochemistry (IHC). Of these putative novel biomarker genes, bridging integrator 2 (BIN2), chemokine receptor 5 (CCR5), and macrophage mannose receptor 1 (MRC1) were upregulated, while spleen tyrosine kinase (SYK) and metalloproteinase 12 (ADAM12) were downregulated in ectopic endometria vs. normal endometria. Meanwhile, 23 potentially therapeutic small molecules for EM were obtained from the cMAP database, among which topiramate, isoflupredone, adiphenine, dexverapamil, MS-275, and celastrol were the top six molecules with the highest absolute enrichment values. This is our first attempt to use the CIBERSORT and WGCNA algorithms for the identification of novel Mϕ2 macrophage-related biomarkers of EM. Our findings provide novel insights into the impact of immune cells on the etiology of EM; nevertheless, further investigation of these key genes and therapeutic drugs is needed to validate their effects on EM.

Intricate Connections between the Microbiota and Endometriosis

Imbalances in gut and reproductive tract microbiota composition, known as dysbiosis, disrupt normal immune function, leading to the elevation of proinflammatory cytokines, compromised immunosurveillance and altered immune cell profiles, all of which may contribute to the pathogenesis of endometriosis. Over time, this immune dysregulation can progress into a chronic state of inflammation, creating an environment conducive to increased adhesion and angiogenesis, which may drive the vicious cycle of endometriosis onset and progression. Recent studies have demonstrated both the ability of endometriosis to induce microbiota changes, and the ability of antibiotics to treat endometriosis. Endometriotic microbiotas have been consistently associated with diminished Lactobacillus dominance, as well as the elevated abundance of bacterial vaginosis-related bacteria and other opportunistic pathogens. Possible explanations for the implications of dysbiosis in endometriosis include the Bacterial Contamination Theory and immune activation, cytokine-impaired gut function, altered estrogen metabolism and signaling, and aberrant progenitor and stem-cell homeostasis. Although preliminary, antibiotic and probiotic treatments have demonstrated efficacy in treating endometriosis, and female reproductive tract (FRT) microbiota sampling has successfully predicted disease risk and stage. Future research should aim to characterize the "core" upper FRT microbiota and elucidate mechanisms behind the relationship between the microbiota and endometriosis.

Endometriosis and Cancer: Exploring the Role of Macrophages

Endometriosis and cancer have much in common, notably their burgeoning of cells in hypoxic milieus, their invasiveness, and their capacity to trigger remodeling, vascularization, and innervation of other tissues. An important role in these processes is played by permissive microenvironments inhabited by a variety of stromal and immune cells, including macrophages. Remarkable phenotypical plasticity of macrophages makes them a promising therapeutic target; some key issues are the range of macrophage phenotypes characteristic of a particular pathology and the possible manners of its modulation. In both endometriosis and cancer, macrophages guard the lesions from immune surveillance while promoting pathological cell growth, invasion, and metastasis. This review article focuses on a comparative analysis of macrophage behaviors in endometriosis and cancer. We also highlight recent reports on the experimental modulation of macrophage phenotypes in preclinical models of endometriosis and cancer.

Functional changes of immune cells: signal of immune tolerance of the ectopic lesions in endometriosis?

RESEARCH QUESTION

What is the potential role of immune cells and their inflammatory cytokines in the pathogenesis, development and establishment of endometriosis?

DESIGN

Peritoneal fluid from 59 women (43 with endometriosis and 16 controls) who had undergone laparoscopic surgery was analysed. Changes in the population of innate and adaptive immune cells, cytokines, chemokines and growth factor expression were measured by flow cytometry, Luminex Technology and enzyme-linked immunosorbent assay.

RESULTS

No differences were found in the frequencies of the innate and adaptive immune cells between women with and without endometriosis. In the peritoneal fluid of women with endometriosis, IL-1β, IL-1RN, IL-2, IL-4, IL-8, IL-10, IL-12 (p70), IL-17α, FGF2, G-CSF, MCP-1, MIP-1α and TNF-α were significantly increased compared with controls. A correlation between IL-2, MCP-1, MIP-1α, TNF-α and the severity of endometriosis was observed. The concentration of neopterin, a possible biomarker for this disease, was increased in women with endometriosis compared with controls.

CONCLUSIONS

The functional activity of immune cells seemed to be reduced despite their numbers remaining unchanged. The data indicate that a shift of T_H cytokine profile occurs, which increases the T_H1-T_H2 ratio. This is driven by the increased levels of the cytokines (TNF-α and IL-2) in women with severe endometriosis.

Symptoms of Adenomyosis and Overlapping Diseases

To summarize and update our current knowledge regarding adenomyosis diagnosis, prevalence, and symptoms. Systematic review of PubMed between January 1972 and April 2020. Search strategy included: "adenomyosis [MeSH Terms] AND (endometriosis[MeSH Term OR prevalence study [MeSH Terms] OR dysmenorrhea[Text Word] OR prevalence[Text Word] OR young adults [Text Word] OR adolesce* [Text Word] OR symptoms[Text Word] OR imaging diagnosis [Text Word] OR pathology[Text Word]. Articles published in English that addressed adenomyosis and discussed prevalence, diagnosis, and symptoms were included. Included articles described: pathology diagnosis, imaging, biopsy diagnosis, prevalence and age of onset, symptoms, and concomitant endometriosis. Sixteen articles were included in the qualitative analysis. The studies are heterogeneous when diagnosing adenomyosis with differing criteria, protocols, and patient populations. Prevalence estimates range from 20% to 88.8% in symptomatic women (average 30-35%) with most diagnosed between 32-38 years old. The correlation between imaging and pathology continues to evolve. As imaging advances, newer studies report younger symptomatic women are being diagnosed with adenomyosis based on both magnetic resonance imaging (MRI) and/or transvaginal ultrasound (TVUS). High rates of concomitant endometriosis create challenges when discerning the etiology of pelvic pain. Symptoms that are historically attributed to endometriosis may actually be caused by adenomyosis. Adenomyosis remains a challenge to identify, assess and research because of the lack of standardized diagnostic criteria, especially in women who wish to retain their uterus. As noninvasive diagnostics such as imaging and myometrial biopsies continue to improve, younger women with variable symptoms will likely create criteria for diagnosis with adenomyosis. The priority should be to create standardized histopathological and imaging diagnoses to gain deeper understandings of adenomyosis.

Influence of Stress on the Vitamin D-Vitamin D Receptor System, Macrophages, and the Local Inflammatory Milieu in Endometriosis

We previously demonstrated the negative impact of stress in an animal model of endometriosis. Although its role is unclear, altered levels of vitamin D (VitD) have been found in patients with this condition. VitD signaling through the VitD receptor (VDR) has anti-proliferative properties and induces an anti-inflammatory phenotype in macrophages. We hypothesized that stress impacts the vitamin D-VDR system, influencing macrophage behavior and the local inflammatory milieu in endometriosis. Endometriosis was surgically induced in female Sprague-Dawley rats, which were then exposed to uncontrollable, controllable, or no stress for 10 days. Sham controls received sutures only. VitD levels were measured by ELISA; cytokine levels by multiplex assay and PCR; and VDR expression and macrophage numbers assessed by immunohistochemistry and immunofluorescence. VDR expression in patient samples was assessed by immunohistochemical staining of a tissue microarray. Serum VitD levels were higher in endometriosis animals compared with sham (p < 0.01) with no significant effect of stress. Uncontrollable stress increased macrophage infiltration (p < 0.01) and VDR expression in vesicles, which were attenuated by controllable stress. Macrophage infiltration correlated with vesicle area (p < 0.05), and peritoneal vitamin D levels correlated with vesicle VDR expression (r = 0.81, p < 0.01). Decreased expression of chemokine ligand 2 (p < 0.05) and TGFβ was observed in endometriosis with uncontrollable stress, whereas IL12 increased with controllable stress. Differential expression of VDR was observed in patient tissues. Stress exacerbates development of cysts in endometriosis through mechanisms that include macrophage recruitment, cytokine changes, and a potentially perturbed VitD:VDR axis, suggesting an impact on the local inflammatory environment.

Characterizing the endometrial fluid cytokine profile in women with endometriosis

PURPOSE

To compare growth factor and cytokine profiles in the endometrial secretions of patients with and without endometriosis to determine whether a particular protein profile is predictive of the disease.

METHODS

Patients undergoing laparoscopic gynecologic surgery for benign indications were recruited for this prospective cohort study. Prior to surgery, endometrial fluid was aspirated and multiplex immunoassay was used to quantify 7 cytokines and growth factors. During surgery, each patient was staged according to the ASRM staging system for endometriosis. Cytokines and growth factors were evaluated using the Mann-Whitney and Kruskal-Wallis tests. Combinations of cytokines were evaluated using logistic regression analysis, and ROC curves were generated to evaluate the predictive capacity of the assay.

RESULTS

Endometrial secretions were analyzed from 60 patients. Nineteen had stage 3-4 endometriosis, 19 had stage 1-2 disease, and 22 had no endometriosis. There were no significant differences between controls and stage 1-2 endometriosis; however, levels of IL-1α and IL-6 were significantly increased in women with moderate-to-severe disease. A combination of IL-1α, IL-1β, and IL-6 in endometrial secretions predicts stage 3-4 endometriosis with an AUC of 0.78. A threshold value of 118 pg/mL yields a sensitivity of 75% and specificity of 70%.

CONCLUSION

Aspiration of endometrial fluid is a safe and effective approach for evaluating the endometrial profile of women with endometriosis. Women with moderate-to-severe endometriosis demonstrate a distinct cytokine profile compared to controls. A combination of IL-1α, IL-1β, and IL-6 in the endometrial secretions is predictive of stage 3-4 endometriosis, but is not predictive of minimal-to-mild disease.

Cancer-associated mutations in endometriosis: shedding light on the pathogenesis and pathophysiology

BACKGROUND

Endometriosis is a benign gynaecological disease. Thus, it came as a complete surprise when it was reported recently that the majority of deep endometriosis lesions harbour somatic mutations and a sizeable portion of them contain known cancer-associated mutations (CAMs). Four more studies have since been published, all demonstrating the existence of CAMs in different subtypes of endometriosis. While the field is still evolving, the confirmation of CAMs has raised many questions that were previously overlooked.

OBJECTIVE AND RATIONALE

A comprehensive overview of CAMs in endometriosis has been produced. In addition, with the recently emerged understanding of the natural history of endometriotic lesions as well as CAMs in normal and apparently healthy tissues, this review attempts to address the following questions: Why has there been such a wild discrepancy in reported mutation frequencies? Why does ectopic endometrium have a higher mutation rate than that of eutopic endometrium? Would the presence of CAMs in endometriotic lesions increase the risk of cancer to the bearers? Why do endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart? What clinical implications, if any, do the CAMs have for the bearers? Do these CAMs tell us anything about the pathogenesis and/or pathophysiology of endometriosis?

SEARCH METHODS

The PubMed database was searched, from its inception to September 2019, for all papers in English using the term 'endometriosis and CAM', 'endometriosis and cancer-driver mutation', 'somatic mutations', 'fibrosis', 'fibrosis and epigenetic', 'CAMs and tumorigenesis', 'somatic mutation and normal tissues', 'oestrogen receptor and fibrosis', 'oxidative stress and fibrosis', 'ARID1A mutation', and 'Kirsten rat sarcoma mutation and therapeutics'. All retrieved papers were read and, when relevant, incorporated into the review results.

OUTCOMES

Seven papers that identified CAMs in endometriosis using various sequencing methods were retrieved, and their results were somewhat different. Yet, it is apparent that those using microdissection techniques and more accurate sequencing methods found more CAMs, echoing recent discoveries that apparently healthy tissues also harbour CAMs as a result of the replicative aging process. Hence endometriotic lesions, irrespective of subtype, if left intact, would generate CAMs as part of replicative aging, oxidative stress and perhaps other factors yet to be identified and, in some rare cases, develop cancer. The published data still are unable to paint a clear picture on pathogenesis of endometriosis. However, since endometriotic epithelial cells have a higher turnover than their stromal counterpart due to cyclic bleeding, and since the endometriotic stromal component can be formed by refresh influx of mesenchymal cells through epithelial-mesenchymal transition, endothelial-mesenchymal transition, mesothelial-mesenchymal transition and other processes as well as recruitment of bone-marrow-derived stem cells and outflow due to smooth muscle metaplasia, endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart. The epithelial and stromal cellular components develop in a dependent and co-evolving manner. Genes involved in CAMs are likely to be active players in lesional fibrogenesis, and hyperestrogenism and oxidative stress are likely drivers of both CAMs and fibrogenesis. Finally, endometriotic lesions harbouring CAMs would conceivably be more refractory to medical treatment, due, in no small part, to their high fibrotic content and reduced vascularity and cellularity.

WIDER IMPLICATIONS

The accumulating data on CAMs in endometriosis have shed new light on the pathogenesis and pathophysiology of endometriosis. They also suggest new challenges in management. The distinct yet co-evolving developmental trajectories of endometriotic stroma and epithelium underscore the importance of the lesional microenvironment and ever-changing cellular identity. Mutational profiling of normal endometrium from women of different ages and reproductive history is needed in order to gain a deeper understanding of the pathogenesis. Moreover, one area that has conspicuously received scant attention is the epigenetic landscape of ectopic, eutopic and normal endometrium.

Physiomimetic Models of Adenomyosis

Adenomyosis remains an enigmatic disease in the clinical and research communities. The high prevalence, diversity of morphological and symptomatic presentations, array of potential etiological explanations, and variable response to existing interventions suggest that different subgroups of patients with distinguishable mechanistic drivers of disease may exist. These factors, combined with the weak links to genetic predisposition, make the entire spectrum of the human condition challenging to model in animals. Here, after an overview of current approaches, a vision for applying physiomimetic modeling to adenomyosis is presented. Physiomimetics combines a system's biology analysis of patient populations to generate hypotheses about mechanistic bases for stratification with in vitro patient avatars to test these hypotheses. A substantial foundation for three-dimensional (3D) tissue engineering of adenomyosis lesions exists in several disparate areas: epithelial organoid technology; synthetic biomaterials matrices for epithelial–stromal coculture; smooth muscle 3D tissue engineering; and microvascular tissue engineering. These approaches can potentially be combined with microfluidic platform technologies to model the lesion microenvironment and can potentially be coupled to other microorgan systems to examine systemic effects. In vitro patient-derived models are constructed to answer specific questions leading to target identification and validation in a manner that informs preclinical research and ultimately clinical trial design.

Menstruation: science and society

Women's health concerns are generally underrepresented in basic and translational research, but reproductive health in particular has been hampered by a lack of understanding of basic uterine and menstrual physiology. Menstrual health is an integral part of overall health because between menarche and menopause, most women menstruate. Yet for tens of millions of women around the world, menstruation regularly and often catastrophically disrupts their physical, mental, and social well-being. Enhancing our understanding of the underlying phenomena involved in menstruation, abnormal uterine bleeding, and other menstruation-related disorders will move us closer to the goal of personalized care. Furthermore, a deeper mechanistic understanding of menstruation-a fast, scarless healing process in healthy individuals-will likely yield insights into a myriad of other diseases involving regulation of vascular function locally and systemically. We also recognize that many women now delay pregnancy and that there is an increasing desire for fertility and uterine preservation. In September 2018, the Gynecologic Health and Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development convened a 2-day meeting, "Menstruation: Science and Society" with an aim to "identify gaps and opportunities in menstruation science and to raise awareness of the need for more research in this field." Experts in fields ranging from the evolutionary role of menstruation to basic endometrial biology (including omic analysis of the endometrium, stem cells and tissue engineering of the endometrium, endometrial microbiome, and abnormal uterine bleeding and fibroids) and translational medicine (imaging and sampling modalities, patient-focused analysis of menstrual disorders including abnormal uterine bleeding, smart technologies or applications and mobile health platforms) to societal challenges in health literacy and dissemination frameworks across different economic and cultural landscapes shared current state-of-the-art and future vision, incorporating the patient voice at the launch of the meeting. Here, we provide an enhanced meeting report with extensive up-to-date (as of submission) context, capturing the spectrum from how the basic processes of menstruation commence in response to progesterone withdrawal, through the role of tissue-resident and circulating stem and progenitor cells in monthly regeneration-and current gaps in knowledge on how dysregulation leads to abnormal uterine bleeding and other menstruation-related disorders such as adenomyosis, endometriosis, and fibroids-to the clinical challenges in diagnostics, treatment, and patient and societal education. We conclude with an overview of how the global agenda concerning menstruation, and specifically menstrual health and hygiene, are gaining momentum, ranging from increasing investment in addressing menstruation-related barriers facing girls in schools in low- to middle-income countries to the more recent "menstrual equity" and "period poverty" movements spreading across high-income countries.

The effects of hedgehog ligand neutralising antibody 5E1 in a mouse model of endometriosis

Objective

Endometriosis is a common and painful condition characterised by the formation of endometrial lesions within the peritoneal cavity. Previous studies have suggested a role for hedgehog signalling in the pathogenesis of endometriosis. We investigated the role of hedgehog signalling in the establishment of endometriosis lesions using 5E1, a hedgehog ligand neutralising antibody, and a mouse model of endometriosis. To mimic the initiation of endometriosis by retrograde menstruation, which is believed to occur in humans, donor mice underwent an artificial menstruation protocol. Fragments of menstrual endometrium were injected into the peritoneal cavity of estrogen primed recipients. Recipients received twice weekly injections of 5E1 or an isotype matched control antibody for three weeks. Lesions were collected and analysed for markers of epithelium, proliferation and apoptosis by immunofluorescence microscopy.

Results

Treatment with 5E1 reduced the number of lesions found on the mesentery. No significant changes were found in the size of lesions, abundance of endometrial epithelial cells, proliferation or apoptosis.

Comparison of cytokines in the peritoneal fluid and conditioned medium of adolescents and adults with and without endometriosis

PROBLEM

To compare inflammatory- and immune-associated peritoneal cytokines of adolescents and adults with and without endometriosis.

METHODS OF STUDY

In a nested case-control study in multiple university-affiliated scientific centers, ten adolescents and thirteen adults with visually and histologically confirmed endometriosis (cases), thirteen adolescents with visually suspected endometriosis but indeterminate (seven patients) or negative (six patients) histology, and fifteen adults undergoing surgery for non-malignant gynecologic disease without endometriosis (controls) underwent laparoscopic aspiration of peritoneal fluid (PF), from which PF and conditioned medium (CM) cytokine levels were assayed.

RESULTS

Compared to adults with endometriosis, MCP-3, IL-12p40, MIP-1β, and IL-15 were significantly higher among adolescents with endometriosis, while TNF-β and CTACK were lower among adolescents. These differences were similar comparing adolescents with endometriosis to adult controls except for MIP-1β, which was not statistically different. MIP-1β was, however, the only cytokine observed to differ between adult cases and controls. There were no significant differences in CM cytokines among the three groups. Results were similar when analyses were restricted to samples collected (a) during menstrual cycle days 1-10, (b) from patients unexposed to exogenous hormones, or (c) from all adolescents despite presence or absence of histologic endometriosis.

CONCLUSION

Biologically relevant and statistically significant differences in six PF cytokines were observed and suggest a more pro-invasion cytokine profile among adolescents with endometriosis. Adolescents with endometriosis have unique peritoneal cytokine profiles and molecular behavior when compared to adults with and without endometriosis.

Cytokine and growth factor profile in endometriosis: a multiplex analysis of peritoneal fluid to assess diagnostic utility

We aimed to assay cytokines and growth factors in peritoneal fluid samples from women with and without endometriosis to understand the inflammatory milieu, and assess their potential diagnostic utility. This cross-sectional study conducted at a tertiary care hospital included 54 women, aged 20-45 years, with regular menstrual history and undergoing diagnostic/therapeutic laparoscopy for infertility and/or pain. Peritoneal fluid samples were collected after insertion of trocar & laparoscope but prior to other surgical intervention. A multiplex immunoassay of 27 cytokines and growth factors was performed. The concentration of FGF2 and CSF3 were significantly lower in women with endometriosis than without endometriosis (p = .043 and .003, respectively). The levels of CCL2 and IL1RN were significantly higher in moderate-severe than in minimal-mild endometriosis (p = .038 and .043, respectively). Phase-specific comparison revealed that in proliferative phase, the levels of CSF2 and CSF3 were lower in women with endometriosis than without the disease (p = .047 and .013, respectively). The ROC curve analysis provided a cutoff value 0.78 and 0.76 for FGF2 and CSF3, respectively. Cytokines and growth factors such as FGF2, CSF3, CSF2, CCL2 and IL1RN seem to contribute to the pathogenesis of endometriosis and may have a potential utility for the diagnosis of endometriosis.

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

Objective

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

Methods

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

Results

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

Conclusion

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