Inflammation In Endometriosis Research Articles

Nociceptor-to-macrophage communication through CGRP/RAMP1 signaling drives endometriosis-associated pain and lesion growth in mice

Endometriosis is a debilitating and painful gynecological inflammatory disease affecting up to 15% of women and transgender men. Current treatments are ineffective for a substantial proportion of patients, underscoring the need for additional therapies with long-term benefits. Nociceptors release neuropeptides, such as calcitonin gene–related peptide (CGRP), which are known to shape immunity through neuroimmune communication. Given the comorbidity between endometriosis and migraine and the integral role of immune cells and inflammation in endometriosis, we investigated the role of CGRP-mediated neuroimmune communication in endometriosis. Using samples from eight patients with endometriosis and a nonsurgical mouse model of the disease, we found that mouse and human endometriosis lesions contain both CGRP and its coreceptor, receptor activity modifying protein 1 (RAMP1). In mice, nociceptor ablation reduced pain, monocyte recruitment, and lesion size, suggesting that nociceptor activation and neuropeptide release contribute to endometriosis lesion growth and pain. Mechanistically, CGRP changed the phenotype of macrophages to a pro-endometriosis phenotype. CGRP-stimulated macrophages demonstrated impaired efferocytosis and supported increased endometrial cell growth in a RAMP1-dependent manner. Treatment of lesion-bearing mice with US Food and Drug Administration–approved drugs that block CGRP-RAMP1 signaling reduced mechanical hyperalgesia, spontaneous pain, and lesion size. Together, our data demonstrated the effectiveness and underlying cellular mechanisms of nonhormonal and nonopioid CGRP/RAMP1 blockade in a mouse model of endometriosis, suggesting that targeting this axis may lead to clinical benefit for patients with endometriosis.

Luoshi Neiyi Prescription inhibits estradiol synthesis and inflammation in endometriosis through the HIF1A/EZH2/SF-1 pathway

Ethnopharmacological relevanceEndometriosis (EMS) is a common gynecological disease that causes dysmenorrhea, chronic pelvic pain and infertility. Luoshi Neiyi Prescription (LSNYP), a traditional Chinese medicine (TCM) formula, is used to relieve EMS in the clinic. AimsThis study aimed to examine the active components of LSNYP and the possible mechanism involved in its treatment of EMS. Materials and methodsUltrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was used to identify the chemical components of LSNYP. Human primary ectopic endometrial stromal cells (ecESCs) and eutopic endometrial stromal cells (euESCs) were isolated, and the expression levels of hypoxia inducible factor 1A (HIF1A), enhancer of zeste homolog 2 (EZH2) and steroidogenic factor 1 (SF-1) were detected by immunofluorescence and qPCR. Cobalt chloride (CoCl2) was utilized to construct an in vitro hypoxic environment, and lentiviruses were engineered to downregulate HIF1A and EZH2 and upregulate EZH2. Subsequently, the expression levels of HIF1A, EZH2, and SF-1 were measured using qPCR or western blotting. The binding of EZH2 to the SF-1 locus in ESCs was examined via ChIP. Furthermore, the effects of LSNYP on the HIF1A/EZH2/SF-1 pathway were evaluated both in vitro and in vivo. ResultsA total of 185 components were identified in LSNYP. The protein and gene expression levels of HIF1A and SF-1 were increased, whereas those of EZH2 were decreased in ecESCs. After treating euESCs with 50 μmol L−1 CoCl2 for 24 h, cell viability and estradiol (E2) production were enhanced. Hypoxia decreased EZH2 protein expression, while si-HIF1A increased it. SF-1 was increased when EZH2 was downregulated in normal and hypoxic environments, whereas the overexpression of EZH2 led to a decrease in SF-1 expression. ChIP revealed that hypoxia reduced EZH2 binding to the SF-1 locus in euESCs. In vitro, LSNYP-containing serum decreased E2 and prostaglandin E2 (PGE2) production, inhibited cell proliferation and invasion, and reduced the expression of HIF1A, SF-1, steroidogenic acute regulatory protein (StAR), and aromatase cytochrome P450 (P450arom). In vivo, LSNYP suppressed inflammation and adhesion and inhibited the HIF1A/EZH2/SF-1 pathway in endometriotic tissues. ConclusionsLSNYP may exert pharmacological effects on EMS by inhibiting E2 synthesis and inflammation through regulation of the HIF1A/EZH2/SF-1 pathway. These results suggest that LSNYP may be a promising candidate for the treatment of EMS.

The Dysregulated IL-23/TH17 Axis in Endometriosis Pathophysiology.

Endometriosis is a chronic inflammatory disease in which endometrial-like tissue grows ectopically, resulting in pelvic pain and infertility. IL-23 is a key contributor in the development and differentiation of TH17 cells, driving TH17 cells toward a pathogenic profile. In a variety of inflammatory and autoimmune disorders, TH17 cells secrete proinflammatory cytokines, including IL-17, contributing to disease pathophysiology. Our studies and others have implicated IL-17 and TH17 cell dysregulation in endometriosis, which is associated with disease severity. In this article, we address whether IL-23-driven TH17 cells contribute to cardinal features of lesion proliferation, vascularization, and inflammation in endometriosis using patient samples, representative cell lines, and our established mouse model of endometriosis. The results indicated dysregulated expression of key genes in the IL-23/TH17 axis in patient ectopic and eutopic endometrial samples and increased IL-23 protein in patient plasma compared with controls. In vitro studies using primary human TH cells determined that rIL-23 mixture treatment increased pathogenic TH17 cell frequency. Similarly, rIL-23 treatment of cell lines (12Z cells, EECCs, HUVECs, and hESCs) representative of the endometriotic lesion microenvironment increased cytokines and growth factors, which play a role in lesion establishment and maintenance. In a syngeneic mouse model of endometriosis, rIL-23 treatment altered numbers of myeloid and T cell subsets in peritoneal fluid and increased giant cells within the lesion. Lesions from rIL-23-treated mice did not reveal significant alterations in proliferation/vascularization, although trends of increased proliferation and vascularization were observed. Collectively, these findings provide insights into the impact of the IL-23/TH17 axis on local immune dysfunction and broadly on endometriosis pathophysiology.

Bioinformatic Analysis of m6A Regulator-Mediated RNA Methylation Modification Patterns and Immune Microenvironment Characterization in Endometriosis.

Epigenetic regulation plays an essential role in immunity and inflammation in endometriosis. In this study, we aimed to explore differences in m6A regulators between endometriosis patients and normal women and analyze the effect of m6A modification on immune and inflammatory microenvironment. The samples for analysis were downloaded from the Gene Expression Omnibus database, including ectopic endometrium (EC), eutopic endometrium (EU), and normal eutopic endometrium (NM) samples from non-endometriosis women. The validation process involved utilizing our previous RNA-sequencing data. Subsequently, a correlation analysis was performed to ascertain the relationship between m6A and the inflammatory microenvironment profile, encompassing infiltrating immunocytes, immune-inflammation reaction gene sets, and human leukocyte antigen genes. LASSO analyses were used to develop risk signature. The findings of this study indicate that the m6A regulators FTO were observed to be significantly up-regulated, while YTHDF2, CBLL1, and METTL3 were down-regulated in endometriosis tissues. The CIBERSORT analysis revealed that the local inflammatory microenvironment of ectopic lesions plays a crucial role in the development of endometriosis. Notably, M2 macrophages exhibited a significant difference between the EC and NM groups. Moreover, M2 macrophages demonstrated a positive correlation with FTO (0.39) and a negative correlation with CBLL1 (-0.35). Furthermore, consistent clustering of EC and EU samples resulted in the identification of three distinct cell subtypes. Among different cell subtypes, significant differences were in immunoinfiltrating cells, plasma cells, naive CD4 T cells, memory activated CD4 T cells, gamma delta T cells, resting NK cells and activated NK cells but not in macrophages. Furthermore, the identification of various compounds capable of targeting these m6A genes was achieved. In conclusions, our integrated bioinformatics analysis results demonstrated that m6A-related genes METTL3, CBLL1 and YTHDF2 may be useful biomarkers for endometriosis in ectopic endometrium. The potential therapeutic approach of targeting m6A regulators holds promise for the treatment of endometriosis.

O-028 Genital tract infection and pelvic surgery contribute to the development of endometriosis

Abstract Study question Was the incidence of endometriosis in women with a recent history of genital infection, pelvic surgery, or both increased? Summary answer The pelvic inflammation resulting from genital infection and pelvic surgical injury may play a role in developing endometriosis. What is known already Endometriosis is a multifactorial disease, and inflammation is considered a core pathology. Inflammation occurs due to pathogenic infection and tissue injury, and genital tract infection and surgical injury can be inducers for pelvic inflammation in endometriosis. Study design, size, duration A retrospective cohort study using the Korean National Health Insurance Service -National Sample Cohort I (KNHIS-SC I) from 2002-2013 (N = 1,025,340) was performed. Participants/materials, setting, methods 20- to 49-year-old women diagnosed with genital tract infections (GTI) or who underwent pelvic surgeries between 2002 and 2008 were collected and followed up for five years. A total of 30,336 women were diagnosed with GTI, 2,894 women underwent pelvic surgery, and 788 women with GTI and pelvic surgery were enrolled in each study. The comparison groups matched sociodemographic factors for each group were collected. The incidence of endometriosis in each group was analyzed. Main results and the role of chance The incidence of endometriosis per 1,000 person-year was 5.37, 5.17, and 20.81 in each case group and was significantly higher than in each comparison group. A recent history of GTI increased an adjusted hazard ratio (aHR) of 2.29 (1.99-2.63, 95% confidence interval) for the development of endometriosis. The aHRs of pelvic surgery history and the history of both GTI and pelvic surgery were 2.10 and 7.82, respectively. Limitations, reasons for caution The diagnosis and treatment codes registered on the NHIS data are used to claim HIRA NHI benefits, which may differ from the diagnosis or treatment performed in practice and it does not contain the used diagnostic method, disease severity, and the disease led to pelvic surgery were not specified. Wider implications of the findings Active treatment of genital infections and careful surgical procedures to minimize tissue injury may reduce the incidence of pelvic endometriosis. Trial registration number Not Applicable

Ligustrazine inhibits inflammatory response of human endometrial stromal cells through the STAT3/IGF2BP1/RELA axis

Context Endometriosis (EMs) is a gynecological disorder. Ligustrazine has been reported to exert an anti-inflammatory effect on EMs. However, the underlying mechanisms are not completely understood. Objective To investigate the effects of ligustrazine on the progression of EMs and the underlying regulatory mechanisms. Materials and methods Human endometrial stromal cells (HESCs) were isolated from patients with EMs or control subjects. HESCs were treated with 25, 50, 100, or 200 μM ligustrazine for 1, 3, 6, or 12 h. Western blot and enzyme-linked immunosorbent assays were performed to determine the levels of proteins and inflammatory cytokines, respectively. The binding between STAT3 and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was assessed by chromatin immunoprecipitation and dual-luciferase reporter assays. The relationship between IGF2BP1 and RELA was assessed by RNA immunoprecipitation and RNA pull-down assay. Results Phosphorylated STAT3, IGF2BP1, RELA, TNF-α, IL-6, and IL-1β were upregulated in EMs tissues compared with control tissues (by 1.79-, 2.55-, 1.58-, 3.01-, 2.55-, and 3.34-fold, respectively). Ligustrazine inhibited the expression of p-STAT3, IGF2BP1, RELA, IL-6, TNF-α, and IL-1β. Overexpression of STAT3 promoted RELA-mediated inflammatory responses, while ligustrazine (100 µM) notably reversed this phenomenon. Ligustrazine also alleviated RELA-induced inflammation via downregulating IGF2BP1. STAT3 bound to the promoter of IGF2BP1, and IGF2BP1 bound to the RELA mRNA. Discussion and conclusion Ligustrazine inhibited inflammation in EMs via regulating the STAT3/IGF2BP1/RELA axis. These findings propose a new agent against EMs and support the development of ligustrazine-based treatment strategies for EMs.

Decreased Innate Migration of Pro-Inflammatory M1 Macrophages through the Mesothelial Membrane Is Affected by Ceramide Kinase and Ceramide 1-P.

The retrograde flow of endometrial tissues deposited into the peritoneal cavity occurs in women during menstruation. Classically (M1) or alternatively (M2) activated macrophages partake in the removal of regurgitated menstrual tissue. The failure of macrophage egress from the peritoneal cavity through the mesothelium leads to chronic inflammation in endometriosis. To study the migration differences of macrophage phenotypes across mesothelial cells, an in vitro model of macrophage egress across a peritoneal mesothelial cell monolayer membrane was developed. M1 macrophages were more sessile, emigrating 2.9-fold less than M2 macrophages. The M1 macrophages displayed a pro-inflammatory cytokine signature, including IL-1α, IL-1β, TNF-α, TNF-β, and IL-12p70. Mass spectrometry sphingolipidomics revealed decreased levels of ceramide-1-phosphate (C1P), an inducer of migration in M1 macrophages, which correlated with its poor migration behavior. C1P is generated by ceramide kinase (CERK) from ceramide, and blocking C1P synthesis via the action of NVP231, a specific CERK chemical inhibitor, prohibited the emigration of M1 and M2 macrophages up to 6.7-fold. Incubation with exogenously added C1P rescued this effect. These results suggest that M1 macrophages are less mobile and have higher retention in the peritoneum due to lower C1P levels, which contributes to an altered peritoneal environment in endometriosis by generating a predominant pro-inflammatory cytokine environment.

RF34 | PMON229 TNFa-Induced Altered miRNA Expression Links to Inflammation in Endometriosis

Abstract Endometriosis is a common gynecological inflammatory disorder, which is characterized by immune system dysregulation with initiation and progression. It affects 5% to 15% of reproductive-age women and is present in as many as 30% to 50% of patients with infertility and/or pain. In previous studies, including ours, have demonstrated that several cytokines have been associated with the evolution of endometriosis, including tumor necrosis factor-a (TNFa). TNFa is a non-glycosylated protein which has potent inflammatory, cytotoxic, and angiogenic potential. Therefore, in the current studies, we examined the effects of TNFa over a time course in the regulation of proinflammatory and proangiogenic microRNAs (miRNAs) in primary cultures of normal endometrial stromal cells (NESC) and compared with the untreated cells derived from eutopic endometrium of endometriosis subjects (EESC). miRNAs are short, 18- to 22-nucleotide– size, non-coding RNAs that act as post-transcriptional modulators of gene expression and are involved in the pathogenesis of endometriosis. Using NanoString nCounter-based assays and quantitative RT-PCR, we have identified levels of several proinflammatory and proangiogenic miRNAs higher in EESC than NESC. NESC treatment with TNFa significantly altered the expression of proinflammatory and proangiogenic miRNAs in a time-dependent manner. Notably, TNFa significantly decreased phosphorylation of the PI3K, AKT, and ERK signaling pathways. Moreover, treatment of EESC and NESC with curcumin (diferuloylmethane, CUR), an anti-inflammatory folk medicine in Asian countries, significantly increased the expression of anti-inflammatory and anti-angiogenic miRNAs in a dose- and time-dependent manner. These findings demonstrate higher inflammatory, and proangiogenic miRNA production in EESC may be due to a higher concentration of TNFa than NESC under basal conditions. Therefore, suppressing TNFa may reduce the inflammatory and angiogenic miRNA associated with endometriosis. Sources of Research Support: This study was supported in part by National Institutes of Health Grants 1SC3 GM113751, U01, 1SC1 GM130544, HD66439, 1R01HD057235, U54 CA118948, HD41749, S21MD000101 and G12-MD007602. This investigation was conducted in a facility constructed with support from Research Facilities Improvement Grant #C06 RR018386 from NIH/NCRR. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 1:06 p.m. - 1:11 p.m.

Persistent activation of signal transducer and activator of transcription 3 via interleukin-6 trans-signaling is involved in fibrosis of endometriosis.

Is activation of signal transducer and activator of transcription 3 (STAT3) via interleukin-6 (IL-6) trans-signaling involved in fibrosis of endometriosis? Persistent activation of STAT3 via IL-6 trans-signaling is involved in fibrosis of endometriosis. Our previous study showed that sustained low-grade inflammation promotes a fibrotic phenotype in endometriotic stromal cells. However, the underlying mechanisms of the establishment of non-resolving, low-grade inflammation in endometriosis remain to be clarified. Endometrial and/or endometriotic samples of 60 patients who had histological evidence of deep endometriosis and endometrial samples from 32 healthy fertile women were analyzed. The effects of priming with ligands of Toll-like receptors (TLRs) 2, 3 and 4 on secretion of inflammatory mediators (tumor necrosis factor-α, C-X-C motif chemokine ligand-10 [CXCL-10], IL6 and IL-10) after a second challenge with TLR ligands in endometrial and endometriotic stromal cells were investigated. Then, the effects of IL-6/soluble (s) IL-6 receptor (R)/STAT3 signaling, as well as inhibition of STAT3 activation by knockdown of STAT3 or pharmacological inhibition (S3I-201), on the pro-fibrotic phenotype in endometrial and endometriotic stromal cells in vitro were investigated. Priming with TLR ligands for 4 h had no significant effects, whereas 24 h of priming significantly decreased secretion of IL-6, after a second challenge in endometrial stromal cells of healthy women. In endometriotic stromal cells, whereas 24 h of priming had no significant effects, priming with TLR ligands for 4 h significantly increased secretion of IL-6 after a second challenge. IL-6/soluble IL-6 receptor (sIL-6R) induced a pro-fibrotic phenotype (cell proliferation, collagen type I synthesis, α-smooth muscle actin positive stress fibers, cell migration and collagen gel contraction) as well as nuclear factor-kappa B (NF-κB) activation of endometriotic stromal cells. In contrast, IL-6/sIL-6R had no significant effects on either a pro-fibrotic phenotype or NF-κB activation of endometrial stromal cells of healthy women. Stimulation with transforming growth factor (TGF)-β1 and/or IL-6/sIL-6R for 1 h and 48 h activated STAT3, but induced very low or no suppressor of cytokine signaling (SOCS) 1 and 3 protein expression in endometriotic stromal cells. In endometrial stromal cells of healthy women, IL-6/sIL-6R-induced STAT3 and SOCS1/3 expression at 1 h, whereas no STAT3 activation was detected at 48 h. Knockdown of STAT3 gene or S3I-201 (a STAT3 inhibitor) decreased the IL-6/sIL-6R-induced pro-fibrotic phenotype as well as NF-κB activation and TGF-β1-induced cell proliferation of endometriotic stromal cells. N/A. In vivo studies are required to confirm the present in vitro results. However, it remains challenging to mimic non-resolving chronic inflammation in animal models, as active inflammation can resolve spontaneously. Dysfunction of negative regulators of IL-6/sIL-6R/STAT3 signaling may cause persistent activation of STAT3 in endometriosis. Since STAT3 activation in the endometrium is essential for successful embryo implantation, treatment with STAT3 inhibitors would not be appropriate for women wishing to conceive. However, targeting impaired negative regulation of IL-6/sIL-6R/STAT3 signaling may still represent a promising avenue for the treatment of endometriosis. This study was supported in part by the KARL STORZ SE & Co. KG (Tuttlingen, Germany). There are no conflicts of interest.

Genetics and Inflammation in Endometriosis: Improving Knowledge for Development of New Pharmacological Strategies.

According to a rich body of literature, immune cell dysfunctions, both locally and systemically, and an inflammatory environment characterize all forms of endometriosis. Alterations in transcripts and proteins involved in the recruitment of immune cells, in the interaction between cytokines and their receptors, cellular adhesion and apoptosis have been demonstrated in endometriotic lesions. The objective of this narrative review is to provide an overview of the components and mechanisms at the intersection between inflammation and genetics that may constitute vanguard therapeutic approaches in endometriosis. The GWAS technology and pathway-based analysis highlighted the role of the MAPK and the WNT/β-catenin cascades in the pathogenesis of endometriosis. These signaling pathways have been suggested to interfere with the disease establishment via several mechanisms, including apoptosis, migration and angiogenesis. Extracellular vesicle-associated molecules may be not only interesting to explain some aspects of endometriosis progression, but they may also serve as therapeutic regimens per se. Immune/inflammatory dysfunctions have always represented attractive therapeutic targets in endometriosis. These would be even more interesting if genetic evidence supported the involvement of functional pathways at the basis of these alterations. Targeting these dysfunctions through next-generation inhibitors can constitute a therapeutic alternative for endometriosis.

Efficacy of niclosamide on the intra-abdominal inflammatory environment in endometriosis.

Endometriosis, a common gynecological disease, causes chronic pelvic pain and infertility in women of reproductive age. Due to the limited efficacy of current therapies, a critical need exists to develop new treatments for endometriosis. Inflammatory dysfunction, instigated by abnormal macrophage (MΦ) function, contributes to disease development and progression. However, the fundamental role of the heterogeneous population of peritoneal MΦ and their potential druggable functions is uncertain. Here we report that GATA6-expressing large peritoneal MΦ (LPM) were increased in the peritoneal cavity following lesion induction. This was associated with increased cytokine and chemokine secretion in the peritoneal fluid (PF), as well as MΦ infiltration, vascularization and innervation in endometriosis-like lesions (ELL). Niclosamide, an FDA-approved anti-helminthic drug, was effective in reducing LPM number, but not small peritoneal MΦ (SPM), in the PF. Niclosamide also inhibits aberrant inflammation in the PF, ELL, pelvic organs (uterus and vagina) and dorsal root ganglion (DRG), as well as MΦ infiltration, vascularization and innervation in the ELL. PF from ELL mice stimulated DRG outgrowth in vitro, whereas the PF from niclosamide-treated ELL mice lacked the strong stimulatory nerve growth response. These results suggest LPM induce aberrant inflammation in endometriosis promoting lesion progression and establishment of the inflammatory environment that sensitizes peripheral nociceptors in the lesions and other pelvic organs, leading to increased hyperalgesia. Our findings provide the rationale for targeting LPM and their functions with niclosamide and its efficacy in endometriosis as a new non-hormonal therapy to reduce aberrant inflammation which may ultimately diminish associated pain.

HMGB1 Mediated Inflammation and Autophagy Contribute to Endometriosis.

AimHigh mobility group box (HMGB)-1 has been implicated in endometriosis due to the important regulatory roles of inflammation in endometriosis. The aim of the present study was to explore the roles of HMGB-1 in endometriosis and to elucidate the underlying mechanism.MethodsEndometrial specimens were collected from women with endometriosis and healthy volunteers. Immunohistochemistry staining was used to determine the expression patterns and localization of HMGB-1 in the normal, eutopic and ectopic endometrial tissues. Western blotting and qRT-PCR were used to determine the mRNA and protein levels of inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor (TNF)-α and IL-1β], autophagy-related markers [beclin-1, autophagy-related (atg)13, microtubule-associated protein light chain (LC)3-I, LC-II and p62] and HMGB-1, respectively. Spearman’s rank correlation analysis was employed to investigate the correlation between HMGB-1 with inflammatory cytokines and beclin-1. Besides, human endometrial stromal cells (HESCs) were isolated from ectopic endometrium and subsequently transfected with shRNA against HMGB-1. After the transfected cells were subjected to hypoxia, ELISA was used to determine the levels of HMGB-1 and inflammatory cytokines in the cell supernatant. Western blotting was used to determine the expression levels of autophagy-related markers in the cells.ResultsPositive correlations were observed between HMGB-1 and the inflammatory cytokines. In addition, a positive correlation was also identified between HMGB-1 and beclin-1 in the ectopic endometrium. Further results demonstrated that autophagy-related markers beclin-1, atg13 and p62 were significantly upregulated in the ectopic endometrium. In addition, HMGB-1 knockdown suppressed the levels of inflammatory cytokines IL-6, TNF-α and IL-1β and autophagy-related markers beclin-1 and atg13, while upregulated p62 in HESCs under hypoxic condition.ConclusionKnockdown of HMGB-1 under hypoxic condition regulated inflammatory cytokines and autophagy-related markers. HMGB-1 might contribute to the development of endometriosis in part through regulating inflammatory response and autophagy.

CLTA-4 Expression is Associated with the Maintenance of Chronic Inflammation in Endometriosis and Infertility.

Altered immune mechanisms are implicated in the pathogenesis of endometriosis. CTLA-4 is a membrane receptor that favors the anergic state of lymphocytes, which may disrupt the immune system response in the endometriotic environment. In this study, we examined the expression of CTLA-4 on T and B cells by flow cytometry and its levels in blood serum and peritoneal fluid by ELISA. Levels of CTLA-4+ T cells were significantly higher in patients with more advanced endometriosis than in those with less advanced disease. Additionally, the negative correlation of CTLA-4+ T lymphocytes and the percentage of NK and NKT-like cells in women with endometriosis and infertility may indicate a different etiopathogenesis of endometriosis accompanying infertility. Our findings shed light on the potential of CTLA-4 in developing new diagnostic and therapeutic approaches in endometriosis management.

Inflammatory Mediators and Pain in Endometriosis: A Systematic Review.

Background: pain is one of the main symptoms of endometriosis and it has a deleterious effect on a patients’ personal and social life. To date, the clinical management of pain includes prolonged medication use and, in some cases, surgery, both of which are disruptive events for patients. Hence, there is an urgency for the development of a sufficient non-invasive medical treatment. Inflammation is one of the causative factors of pain in endometriosis. It is well established that inflammatory mediators promote angiogenesis and interact with the sensory neurons inducing the pain signal; the threshold of pain varies and it depends on the state and location of the disease. The inhibition of inflammatory mediators’ synthesis might offer a novel and effective treatment of the pain that is caused by inflammation in endometriosis. Objectives: patients with endometriosis experience chronic pelvic pain, which is moderate to severe in terms of intensity. The objective of this systematic review is to highlight the inflammatory mediators that contribute to the induction of pain in endometriosis and present their biological mechanism of action. In addition, the authors aim to identify new targets for the development of novel treatments for chronic pelvic pain in patients with endometriosis. Data Sources: three databases (PubMed, Scopus, and Europe PMC) were searched in order to retrieve articles with the keywords ‘inflammation, pain, and endometriosis’ between the review period of 1 January 2016 to 31 December 2020. This review has been registered with PROSPERO (registry number: CRD42020171018). Eligibility Criteria: only original articles that presented the regulation of inflammatory mediators and related biological molecules in endometriosis and their contribution in the stimulation of pain signal were included. Data Extraction: two authors independently extracted data from articles, using predefined criteria. Results: the database search yielded 1871 articles, which were narrowed down to 56 relevant articles of interest according to the eligibility criteria. Conclusions: inflammatory factors that promote angiogenesis and neuroangiogenesis are promising targets for the treatment of inflammatory pain in endometriosis. Specifically, CXC chemokine family, chemokine fractalkine, and PGE2 have an active role in the induction of pain. Additionally, IL-1β appears to be the primary interleukin (IL), which stimulates the majority of the inflammatory factors that contribute to neuroangiogenesis along with IL-6. Finally, the role of Ninj1 and BDNF proteins needs further investigation.

Immunologic factors involved in the malignant transformation of endometriosis to endometriosis-associated ovarian carcinoma.

Endometriosis is a risk factor for low-grade serous, clear cell, and endometroid ovarian carcinoma. In both endometriosis and ovarian carcinoma, immunological factors are associated with clinical outcome. Chronic inflammation in endometriosis may be linked to tumorigenesis, but exact processes contributing to endometriosis-associated ovarian carcinoma remain unknown. This review aims to describe potential immunological factors involved in the malignant transformation of endometriosis into ovarian carcinoma. PubMed and Embase were searched from inception up to October 2020 for studies comparing immunological processes in endometriosis and endometriosis-associated ovarian carcinoma. Detailed analysis of immune components in the malignant transformation of endometriosis into endometriosis-associated ovarian carcinoma is lacking. Altered levels of chemokines and cytokines as IL-6, IL-8, IL-10, and TNF-α are reported and the function, number and polarization of NK cells, dendritic cells, and monocytes differ between endometriosis and associated ovarian carcinoma compared to healthy tissue. In addition, altered inflammasome and complement systems, indicate a role for the immune system in the carcinogenesis of endometriosis. Chronic inflammation in endometriosis may potentially drive inflammation-induced carcinogenesis in endometriosis-associated ovarian carcinoma. Exact immunological pathways and cellular processes remain unknown and require more thorough investigation.

NLRC5 Inhibits Inflammation of Secretory Phase Ectopic Endometrial Stromal Cells by Up-Regulating Autophagy in Ovarian Endometriosis.

Nod-like receptor (NLR) family caspase activation and recruitment domain containing 5 (NLRC5) is a newly identified sub-class of the NLR family. It regulates inflammation and has a key function in innate and adaptive immunologic reactions. Autophagy has been reported to be crucially linked to the pathogenesis of endometriosis. Our recent study identify there is a negative correlation between NLRC5 and autophagy in endometriosis, indicating that NLRC5 and autophagy together act as promising predictors in endometriosis patients. However, the mechanism associating NLRC5 and autophagy in endometriosis is still not completely understood. We hypothesize that autophagy could be involved in NLRC5-mediated inflammation in endometriosis. In order to validate the assumption, we evaluate the effects of NLRC5 and autophagy in the inflammation of ectopic endometrial stromal cells (EESCs) of ovarian endometriosis patients, to specifically determine whether autophagy is involved in NLRC5-mediated inflammation in EESCs. Our results show that over-expression of NLRC5 results in the up-regulation of autophagy in EESCs and inhibition of NLRC5 restricts the level of autophagy in EESCs. Furthermore, over-expression of NLRC5 and promotion of autophagy inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expressions, whereas inhibition of NLRC5 and autophagy up-regulate IL-6 and TNF-α expressions in EESCs. Additionally, promotion of autophagy contributes to the NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs; inhibition of autophagy restricts NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs. Our results suggest that over-expression of NLRC5 promotes autophagy, thereby inhibiting inflammation in ovarian endometriosis.

Atherosclerosis-related biomarkers in women with endometriosis: The effects of dienogest and oral contraceptive therapy.

ObjectiveChronic inflammation in endometriosis is associated with increased risk of future cardiovascular disease; however, no studies have investigated the cardiovascular risk of women who have undergone hormonal therapy for endometriosis. We investigated atherosclerosis-related biomarkers in women with and without endometriosis and the effects of dienogest (DNG) and oral contraceptive (OC) therapies.Study designIn this cross-sectional study, 109 women with endometriosis and 42 control women without endometriosis were enrolled. The endometriosis group was divided into the untreated (n = 34), DNG therapy (n = 33), and OC therapy (n = 42) groups. Lipid profile serum levels, inflammatory marker such as high-sensitivity C-reactive protein, oxidative stress markers such as oxidized low-density lipoprotein and diacron-reactive oxygen metabolites, and atherosclerosis indicators (cardio-ankle vascular index [CAVI] and ankle-brachial pressure index [ABI]) were measured.ResultsThe median treatment duration was 28 months in the DNG group and 32.5 months in the OC group. Triglyceride levels were higher in the OC group than in the other three groups (P < 0.05). Regarding markers of inflammation and oxidative stress, log high-sensitivity C-reactive protein and diacron-reactive oxygen metabolites levels were higher in the untreated group than in the control group (P < 0.05), and these markers were further increased in the OC group (log high-sensitivity C-reactive protein: P < 0.05; diacron-reactive oxygen metabolites: P < 0.01), but not in the DNG group. There was no difference in the CAVI and ABI among all groups. Spearman correlation revealed a positive correlation between duration of OC therapy and CAVI (ρ = +0.49; P = 0.002), but no correlation between the duration of DNG therapy and CAVI (ρ = –0.04; P = 0.81).ConclusionsInflammation and oxidative stress markers are increased in women with untreated endometriosis. Treatment with OC, but not with DNG, further increases these levels. There was a positive association between the duration of OC administration and atherosclerosis risk for women with endometriosis. Our results suggest that DNG could be administered to endometriosis without the increased atherosclerosis risk and short-term OC administration for endometriosis is not harmful, however, atherosclerosis risk should be strictly observed.

Curcumin and Endometriosis.

Endometriosis is one of the main common gynecological disorders, which is characterized by the presence of glands and stroma outside the uterine cavity. Some findings have highlighted the main role of inflammation in endometriosis by acting on proliferation, apoptosis and angiogenesis. Oxidative stress, an imbalance between reactive oxygen species and antioxidants, could have a key role in the initiation and progression of endometriosis by resulting in inflammatory responses in the peritoneal cavity. Nevertheless, the mechanisms underlying this disease are still unclear and therapies are not currently efficient. Curcumin is a major anti-inflammatory agent. Several findings have highlighted the anti-oxidant, anti-inflammatory and anti-angiogenic properties of curcumin. The purpose of this review is to summarize the potential action of curcumin in endometriosis by acting on inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis.

Regulation of Inflammation Pathways and Inflammasome by Sex Steroid Hormones in Endometriosis.

Endometriosis is a gynecological disorder characterized by the growth of endometrial tissue (glands and stroma) outside the uterus, mainly in the peritoneal cavity, ovaries, and intestines. This condition shows estrogen dependency and progesterone resistance, and it has been associated with chronic inflammation, severe pain, and infertility, which negatively affect the quality of life in reproductive women. The molecular mechanisms involved in the pathogenesis of endometriosis are not completely understood; however, inflammation plays a key role in the pathophysiology of the disease, mainly by altering the function of immune cells (macrophages, natural killer, and T cells) and increasing levels of pro-inflammatory mediators in the peritoneal cavity, endometrium, and blood. These immune alterations inhibit apoptotic pathways and promote adhesion and proliferation of endometriotic cells, as well as angiogenesis and neurogenesis in endometriotic lesions. It has been demonstrated that hormonal alterations in endometriosis are related to the inflammatory unbalance in this disease. Particularly, steroid hormones (mainly estradiol) promote the expression and release of pro-inflammatory factors. Excessive inflammation in endometriosis contributes to changes of hormonal regulation by modulating sex steroid receptors expression and increasing aromatase activity. In addition, dysregulation of the inflammasome pathway, mediated by an alteration of cellular responses to steroid hormones, participates in disease progression through preventing cell death, promoting adhesion, invasion, and cell proliferation. Furthermore, inflammation is involved in endometriosis-associated infertility, which alters endometrium receptivity by impairing biochemical responses and decidualization. The purpose of this review is to present current research about the role of inflammasome in the pathogenesis of endometriosis as well as the molecular role of sex hormones in the inflammatory responses in endometriosis.

Niclosamide suppresses macrophage-induced inflammation in endometriosis†.

Endometriosis is a common gynecological disease, which causes chronic pelvic pain and infertility in women of reproductive age. Due to limited efficacy of current treatment options, a critical need exists to develop new and effective treatments for endometriosis. Niclosamide is an efficacious and FDA-approved drug for the treatment of helminthosis in humans that has been used for decades. We have reported that niclosamide reduces growth and progression of endometriosis-like lesions via targeting STAT3 and NFĸB signaling in a mouse model of endometriosis. To examine the effects of niclosamide on macrophage-induced inflammation in endometriosis, a total of 29 stage III-IV endometrioma samples were used to isolate human endometriotic stromal cells (hESCs). M1 or M2 macrophages were isolated and differentiated from fresh human peripheral blood samples. Then, hESCs were cultured in conditioned media (CM) from macrophages with/without niclosamide. Niclosamide dose dependently reduced cell viability and the activity of STAT3 and NFκB signaling in hESCs. While macrophage CM stimulated cell viability in hESCs, niclosamide inhibited this stimulation. Macrophage CM stimulated the secretion of proinflammatory cytokines and chemokines from hESCs. Most of these secreted factors were inhibited by niclosamide. These results indicate that niclosamide is able to reduce macrophage-induced cell viability and cytokine/chemokine secretion in hESCs by inhibiting inflammatory mechanisms via STAT3 and/or NFκB signaling.