Toll-Like Receptor 2 Expression as a New Hallmark of Advanced Endometriosis

Comprehensive Management of Bowel Endometriosis: Surgical Techniques, Outcomes, and Best Practices

Bowel endometriosis is a complex condition predominantly impacting women in their reproductive years, which may lead to chronic pain, gastrointestinal symptoms, and infertility. This review highlights current approaches to the diagnosis and management of bowel endometriosis, emphasizing a multidisciplinary strategy. Diagnostic methods include detailed patient history, physical examination, and imaging techniques like transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI), which aid in preoperative planning. Management options range from hormonal therapies for symptom relief to minimally invasive surgical techniques. Surgical interventions, categorized as shaving excision, disc excision, or segmental resection, depend on factors such as lesion size, location, and depth. Shaving excision is preferred for its minimal invasiveness and lower complication rates, while segmental resection is reserved for severe cases. This review also explores nerve-sparing strategies to reduce surgical morbidity, particularly for deep infiltrative cases close to the rectal bulb, anal verge, and rectosigmoid colon. A structured, evidence-based approach is recommended, prioritizing conservative surgery to avoid complications and preserve fertility as much as possible. Comprehensive management of bowel endometriosis requires expertise from both gynecologic and gastrointestinal specialists, aiming to improve patient outcomes while minimizing long-term morbidity.

Peritoneal fluid microbiota profile of patients with deep endometriosis

Endometriosis is a chronic gynecological disease that affects 10 % of reproductive-aged women and characterized by the presence of endometrial tissue outside the uterus. The disease is linked to a pro-inflammatory environment in the peritoneal fluid of patients, with high levels of cytokines, growth factors, and reactive oxygen species. Changes in the peritoneal fluid, such as altered immune cells and cytokines, can be linked to the immune balance in endometriosis. Immunological changes may be related to the presence of microorganisms in the peritoneal fluid that can activate Toll-like receptor (TLR) signaling and trigger an inflammatory response. A high diversity of TLRs has been found in women with endometriosis, and the presence of specific microorganisms in the fluid is suggested to be responsible for the activation of inflammasomes and inflammatory cytokines involved in the development of endometriosis. The present study was conducted at a hospital in southeastern Brazil to test this hypothesis, using a case-control design. Peritoneal fluid from 50 patients was used in this study. The case group consisted of 27 patients with endometriosis and the control group consisted of 23 patients without endometriosis. The samples were stored in a microbiome transport solution, and DNA was extracted and sent for genetic sequencing to identify the microorganisms present. The obtained sequencing reads were processed using a bioinformatics pipeline involving demultiplexing with the Illumina proprietary software, primer detection and removal, error evaluation, quality filtering, error removal using the Deblur software, amplicon sequence variants grouping, and chimera detection using the VSEARCH software. The sheer abundance of the microbiome made it challenging to discern any notable differences between the two groups. Nevertheless, we highlighted the prevalence of three primary bacteria in the peritoneal fluid from patients with endometriosis: Flavobacterium, Pseudomonas, and Bacillus. The results were established after a rigorous experimental design to eliminate potential contamination from extraction kits and handling. Our findings provide valuable insight into the pathogenesis of this disease and can be useful to understand how microbiota and immune system works in endometriosis.

Exploring the Shared Pathogenesis Mechanisms of Endometriosis and Cancer: Stemness and Targeted Treatments of Its Molecular Pathways-A Narrative Review

Endometriosis is a benign disease but with malignant behavior, sharing numerous features with cancers. Endometriosis is the development of endometrial tissue outside the uterus, with the presence of both glands and stroma. Approximately 10% of women of reproductive age suffer from endometriosis; it involves high social costs and affects the patient's quality of life. In this review, we attempt to capture the pathogenesis mechanisms that are common to endometriosis and cancer based on molecular biology, focusing more on the principle of immunological changes and stemness. Clinical applicability will consist of targeted treatments that represent future directions in these diseases, which impose a burden on the healthcare system. Unlike endometriosis, cancer is a disease with fatal evolution, with conventional treatment based on chemo/radiotherapy. Here, we focus on the niche of personalized treatments that target molecular pathways. Our findings show that, in both pathologies, the resistance to treatments is due to the stemness of the stem cells, which might play a role in the appearance and evolution of both diseases. More research is needed before we can draw firm conclusions.

Screening and identification of key biomarkers associated with endometriosis using bioinformatics and next-generation sequencing data analysis

Background

Endometriosis is a common cause of endometrial-type mucosa outside the uterine cavity with symptoms such as painful periods, chronic pelvic pain, pain with intercourse and infertility. However, the early diagnosis of endometriosis is still restricted. The purpose of this investigation is to identify and validate the key biomarkers of endometriosis.

Methods

Next-generation sequencing dataset GSE243039 was obtained from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) between endometriosis and normal control samples were identified. After screening of DEGs, gene ontology (GO) and REACTOME pathway enrichment analyses were performed. Furthermore, a protein–protein interaction (PPI) network was constructed and modules were analyzed using the Human Integrated Protein–Protein Interaction rEference database and Cytoscape software, and hub genes were identified. Subsequently, a network between miRNAs and hub genes, and network between TFs and hub genes were constructed using the miRNet and NetworkAnalyst tool, and possible key miRNAs and TFs were predicted. Finally, receiver operating characteristic curve analysis was used to validate the hub genes.

Results

A total of 958 DEGs, including 479 upregulated genes and 479 downregulated genes, were screened between endometriosis and normal control samples. GO and REACTOME pathway enrichment analyses of the 958 DEGs showed that they were mainly involved in multicellular organismal process, developmental process, signaling by GPCR and muscle contraction. Further analysis of the PPI network and modules identified 10 hub genes, including vcam1, snca, prkcb, adrb2, foxq1, mdfi, actbl2, prkd1, dapk1 and actc1. Possible target miRNAs, including hsa-mir-3143 and hsa-mir-2110, and target TFs, including tcf3 (transcription factor 3) and clock (clock circadian regulator), were predicted by constructing a miRNA-hub gene regulatory network and TF-hub gene regulatory network.

Conclusions

This investigation used bioinformatics techniques to explore the potential and novel biomarkers. These biomarkers might provide new ideas and methods for the early diagnosis, treatment and monitoring of endometriosis.

The role of CD8+ T cells in endometriosis: a systematic review

Background

Endometriosis is a chronic disease affecting 6-10% of women of reproductive age. It is an important cause of infertility and chronic pelvic pain with poorly understood aetiology. CD8+ T (CD8 T) cells were shown to be linked to infertility and chronic pain and play a significant role in lesion clearance in other pathologies, yet their function in endometriosis is unknown. We systematically evaluated the literature on the CD8 T in peripheral blood and endometriosis-associated tissues to determine the current understanding of their pathophysiological and clinical relevance in the disease and associated conditions (e.g. infertility and pelvic pain).

Methods

Four databases were searched (MEDLINE, EMBASE, Web of Science, CINAHL), from database inception until September 2022, for papers written in the English language with database-specific relevant terms/free-text terms from two categories: CD8 T cells and endometriosis. We included peer-reviewed papers investigating CD8 T cells in peripheral blood and endometriosis-associated tissues of patients with surgically confirmed endometriosis between menarche and menopause, and animal models with oestrous cycles. Studies enrolling participants with other gynaecological pathologies (except uterine fibroids and tubal factor infertility used as controls), cancer, immune diseases, or taking immune or hormonal therapy were excluded.

Results

28 published case-control studies and gene set analyses investigating CD8 T cells in endometriosis were included. Data consistently indicate that CD8 T cells are enriched in endometriotic lesions in comparison to eutopic endometrium, with no differences in peripheral blood CD8 T populations between patients and healthy controls. Evidence on CD8 T cells in peritoneal fluid and eutopic endometrium is conflicting. CD8 T cell cytotoxicity was increased in the menstrual effluent of patients, and genomic analyses have shown a clear trend of enriched CD8 T effector memory cells in the eutopic endometrium of patients.

Conclusion

Literature on CD8 T cells in endometriosis-associated tissues is inconsistent. Increased CD8 T levels are found in endometriotic lesions, however, their activation potential is understudied in all relevant tissues. Future research should focus on identifying clinically relevant phenotypes to support the development of non-invasive diagnostic and treatment strategies.

Systematic Review Registration

PROSPERO identifier CRD42021233304.

How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis

Microorganisms inhabiting the human body play an extremely key role in its proper functioning, as well as in the development of the immune system, which, by maintaining the immune balance, allows you to enjoy health. Dysbiosis of the intestinal microbiota, or in the oral cavity or reproductive tract, understood as a change in the number and diversity of all microorganisms inhabiting them, may correlate with the development of many diseases, including endometriosis, as researchers have emphasized. Endometriosis is an inflammatory, estrogen-dependent gynecological condition defined by the growth of endometrial cells outside the uterine cavity. Deregulation of immune homeostasis resulting from microbiological disorders may generate chronic inflammation, thus creating an environment conducive to the increased adhesion and angiogenesis involved in the development of endometriosis. In addition, research in recent years has implicated bacterial contamination and immune activation, reduced gastrointestinal function by cytokines, altered estrogen metabolism and signaling, and abnormal progenitor and stem cell homeostasis, in the pathogenesis of endometriosis. The aim of this review was to present the influence of intestinal, oral and genital microbiota dysbiosis in the metabolic regulation and immunopathogenesis of endometriosis.

Peritoneal immune microenvironment of endometriosis: Role and therapeutic perspectives

Endometriosis, an estrogen-dependent chronic inflammatory disease characterized by the growth of endometrium-like tissues outside the uterine cavity, affects 10% of reproductive-age women. Although the pathogenesis of endometriosis is uncertain, it is widely accepted that retrograde menstruation results in ectopic endometrial tissue implantation. Given that not all women with retrograde menstruation develop endometriosis, immune factors have been hypothesized to affect the pathogenesis of endometriosis. In this review, we demonstrate that the peritoneal immune microenvironment, including innate immunity and adaptive immunity, plays a central role in the pathogenesis of endometriosis. Current evidence supports the fact that immune cells, such as macrophages, natural killer (NK) cells, dendritic cells (DCs), neutrophils, T cells, and B cells, as well as cytokines and inflammatory mediators, contribute to the vascularization and fibrogenesis of endometriotic lesions, accelerating the implantation and development of ectopic endometrial lesions. Endocrine system dysfunction influences the immune microenvironment through overexpressed estrogen and progesterone resistance. In light of the limitations of hormonal therapy, we describe the prospects for potential diagnostic biomarkers and nonhormonal therapy based on the regulation of the immune microenvironment. Further studies are warranted to explore the available diagnostic biomarkers and immunological therapeutic strategies for endometriosis.

Pattern-recognition receptors in endometriosis: A narrative review

Endometriosis is closely associated with ectopic focal inflammation and immunosuppressive microenvironment. Multiple types of pattern recognition receptors (PRRs) are present in the innate immune system, which are able to detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in both intracellular and external environments. However, the exact role of PRRs in endometriosis and the underlying molecular mechanism are unclear. PRRs are necessary for the innate immune system to identify and destroy invasive foreign infectious agents. Mammals mainly have two types of microbial recognition systems. The first one consists of the membrane-bound receptors, such as toll-like receptors (TLRs), which recognize extracellular microorganisms and activate intracellular signals to stimulate immune responses. The second one consists of the intracellular PRRs, including nod-like receptors (NLRs) and antiviral proteins retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5) with helix enzyme domain. In this review, we mainly focus on the key role of PRRs in the pathological processes associated with endometriosis. PRRs recognize PAMPs and can distinguish pathogenic microorganisms from self, triggering receptor ligand reaction followed by the stimulation of host immune response. Activated immune response promotes the transmission of microbial infection signals to the cells. As endometriosis is characterized by dysregulated inflammation and immune response, PRRs may potentially be involved in the activation of endometriosis-associated inflammation and immune disorders. Toll-like receptor 2 (TLR2), toll-like receptor 3 (TLR3), toll-like receptor 4 (TLR4), nod-like receptor family caspase activation and recruitment domain (CARD) domain containing 5 (NLRC5), nod-like receptor family pyrin domain containing 3 (NLRP3), and c-type lectin receptors (CLRs) play essential roles in endometriosis development by regulating immune and inflammatory responses. Absent in melanoma 2 (AIM2)-like receptors (ALRs) and retinoic acid-inducible gene I-like receptors (RLRs) may be involved in the activation of endometriosis-associated immune and inflammation disorders. PRRs, especially TLRs, may serve as potential therapeutic targets for alleviating pain in endometriosis patients. PRRs and their ligands interact with the innate immune system to enhance inflammation in the stromal cells during endometriosis. Thus, targeting PRRs and their new synthetic ligands may provide new therapeutic options for treating endometriosis.

The colonized microbiota composition in the peritoneal fluid in women with endometriosis

PURPOSE

The imbalance of microbiome in vivo is believed to be involved in the pathogenicity of endometriosis. This study aimed to investigate and analyze the composition of bacterial communities in the peritoneal fluid of women with endometriosis.

METHODS

To collect peritoneal fluid samples from women with (N = 36) and without (N = 25) endometriosis in a generalized hospital in Hunan, China during January to December of 2019. Genomic DNA was extracted from peritoneal fluid samples, and targeted amplified for the V4 region of 16S ribosomal RNA gene followed by amplicon sequencing. Non-parametric Wilcoxon rank-sum test and chi-squared test were used to compare and analysis the difference between groups.

RESULTS

Analysis showed that microbiota diversity was similar in the peritoneal fluid of women with or without endometriosis. Ralstonia mainly dominated in the peritoneal fluid of patients in both groups, with an overall relative abundance of 11.15% (95% CI: 10.51-11.80%) in endometriosis patients, followed by Acinetobacter, Pseudomonas, Asticcacaulis, and Methyloversatilis, with no significant difference between endometriosis patients and the control group. Nevertheless, there were microbes with different abundance in peritoneal fluid of the two groups, and the relative abundance was less than 0.5%. Acidovorax (P = 0.01), Devosia (P = 0.03), Methylobacterium (P = 0.03), Phascolarctobacterium (P = 0.03), and Streptococcus (P = 0.04) were more abundant in the peritoneal fluid of endometriosis patients than the controls, while Brevundimonas (P = 0.01) and Stenotrophomonas (P = 0.04) were less abundant.

CONCLUSION

The composition of minority microbiota including Acidovorax, Devosia, Methylobacterium, Phascolarctobacterium, and Streptococcus in peritoneal fluid were found to change among women with endometriosis. Further research is needed to explore the mechanisms of these microorganisms in the pathophysiology of endometriosis.

A systematic review of toll-like receptors in endometriosis

INTRODUCTION

The pathogen-associated molecular patterns and the danger-associated molecular patterns are possibly responsible for the activation of the inflammatory process in endometriosis through the activation of toll-like receptors (TLRs).

OBJECTIVE

The aim of this systematic review was to critically analyze the findings of published articles on TLRs in endometriosis.

METHODS

The keywords used were "endometriosis" and "toll-like" and the search was performed in Pubmed, Scielo and Lilacs databases. This study followed the PRISMA guidelines and the risk of bias of articles was conducted by Newcastle-Ottawa scale (NOS).

RESULTS

Overall, the studies analyzed in this review point toward an increased expression of TLRs two, four and nine in women with endometriosis. Among all TLRs, TLR4 was the most cited receptor.

CONCLUSION

Despite the evidence demonstrating elevated TLR levels in endometriosis, the relationship with the disease is still unclear and needs to be clarified in further studies about innate immune response.

Endometriosis Associated Infertility: A Critical Review and Analysis on Etiopathogenesis and Therapeutic Approaches

Endometriosis represents a frequently diagnosed gynecological affliction in the reproductive timespan of women, defined by symptoms ranging from pelvic pain to infertility. A complex interplay between the genetic profile, hormonal activity, menstrual cyclicity, inflammation status, and immunological factors define the phenotypic presentation of endometriosis. To date, imaging techniques represent the gold standard in diagnosing endometriosis, of which transvaginal ultrasonography and magnetic resonance imaging bring the most value to the diagnostic step. Current medical treatment options for endometriosis-associated infertility focus on either stimulating the follicular development and ovulation or on inhibiting the growth and development of endometriotic lesions. Techniques of assisted reproduction consisting of superovulation with in vitro fertilization or intrauterine insemination represent effective treatment alternatives that improve fertility in patients suffering from endometriosis. Emerging therapies such as the usage of antioxidant molecules and stem cells still need future research to prove the therapeutic efficacy in this pathology.