New insights into the pathophysiology of endometriosis: from chronic inflammation to danger signal

Diagnostic Value of Menstrual Blood Lipidomics in Endometriosis: A Pilot Study

Endometriosis is a prevalent chronic inflammatory disease characterized by a considerable delay between initial symptoms and diagnosis through surgery. The pressing need for a timely, non-invasive diagnostic solution underscores the focus of current research efforts. This study examines the diagnostic potential of the menstrual blood lipidome. The lipid profile of 39 samples (23 women with endometriosis and 16 patients in a control group) was acquired using reverse-phase high-performance liquid chromatography-mass spectrometry with LipidMatch processing and identification. Profiles were normalized based on total ion counts. Significant differences in lipids were determined using the Mann-Whitney test. Lipids for the diagnostic model, based on logistic regression, were selected using a combination of variance importance projection filters and Akaike information criteria. Levels of ceramides, sphingomyelins, cardiolipins, triacylglycerols, acyl- and alkenyl-phosphatidylethanolamines, and alkenyl-phosphatidylcholines increased, while acyl- and alkyl-phosphatidylcholines decreased in cases of endometriosis. Plasmenylphosphatidylethanolamine PE P-16:0/18:1 and cardiolipin CL 16:0_18:0_22:5_22:6 serve as marker lipids in the diagnostic model, exhibiting a sensitivity of 81% and specificity of 85%. The diagnostic approach based on dried spots of menstrual blood holds promise as an alternative to traditional non-invasive methods for endometriosis screening.

Endometriosis, Pain, and Related Psychological Disorders: Unveiling the Interplay among the Microbiome, Inflammation, and Oxidative Stress as a Common Thread

Endometriosis (EM), a chronic condition in endometrial tissue outside the uterus, affects around 10% of reproductive-age women, significantly affecting fertility. Its prevalence remains elusive due to the surgical confirmation needed for diagnosis. Manifesting with a range of symptoms, including dysmenorrhea, dyschezia, dysuria, dyspareunia, fatigue, and gastrointestinal discomfort, EM significantly impairs quality of life due to severe chronic pelvic pain (CPP). Psychological manifestations, notably depression and anxiety, frequently accompany the physical symptoms, with CPP serving as a key mediator. Pain stems from endometrial lesions, involving oxidative stress, neuroinflammation, angiogenesis, and sensitization processes. Microbial dysbiosis appears to be crucial in the inflammatory mechanisms underlying EM and associated CPP, as well as psychological symptoms. In this scenario, dietary interventions and nutritional supplements could help manage EM symptoms by targeting inflammation, oxidative stress, and the microbiome. Our manuscript starts by delving into the complex relationship between EM pain and psychological comorbidities. It subsequently addresses the emerging roles of the microbiome, inflammation, and oxidative stress as common links among these abovementioned conditions. Furthermore, the review explores how dietary and nutritional interventions may influence the composition and function of the microbiome, reduce inflammation and oxidative stress, alleviate pain, and potentially affect EM-associated psychological disorders.

Heme metabolism and HO-1 in the pathogenesis and potential intervention of endometriosis

Endometriosis (EM) is one of the diseases related to retrograded menstruation and hemoglobin. Heme, released from hemoglobin, is degraded by heme oxygenase-1 (HO-1). In EM lesions, heme metabolites regulate processes such as inflammation, redox balance, autophagy, dysmenorrhea, malignancy, and invasion, where macrophages (Mø) play a fundamental role in their interactions. Regulation occurs at molecular, cellular, and pathological levels. Numerous studies suggest that heme is an indispensable component in EM and may contribute to its pathogenesis. The regulatory role of heme in EM encompasses cytokines, signaling pathways, and kinases that mediate cellular responses to external stimuli. HO-1, a catalytic enzyme in the catabolic phase of heme, mitigates heme's cytotoxicity in EM due to its antioxidant, anti-inflammatory, and anti-proliferative properties. Certain compounds may intervene in EM by targeting heme metabolism, guiding the development of appropriate treatments for all stages of endometriosis.

Luteolin attenuates Staphylococcus aureus-induced endometritis through inhibiting ferroptosis and inflammation via activating the Nrf2/GPX4 signaling pathway

Endometritis, a local inflammatory disease, has been known as the most common cause of infertility in mares. In this study, we investigated the protective effects of luteolin on endometritis induced by Staphylococcus aureus (S. aureus) and further clarified the possible molecular mechanisms. An S. aureus-induced endometritis model was established by the infusion of S. aureus into the uterus. Luteolin was intraperitoneally administered to mice 1 h before S. aureus treatment. The results showed that the mice of the S. aureus group showed severe histological changes of uterine tissues, increased myeloperoxidase (MPO) activity, and elevated TNF-α, IL-1β, and IL-6 levels. These changes induced by S. aureus were dose-dependently inhibited by luteolin. Furthermore, luteolin inhibited MDA and Fe2+ production and increased the production of GSH decreased by S. aureus. Luteolin prevented S. aureus-induced endometrial barrier disruption through up-regulating ZO-1 and occludin expression. Luteolin dramatically inhibited S. aureus-induced NF-κB activation. The expression of Nrf2 and HO-1 was increased by luteolin. In addition, the inhibitory effects of luteolin on S. aureus-induced endometritis were reversed in Nrf2 knockdown mice. In conclusion, these data indicated that luteolin protected mice against S. aureus-induced endometritis through inhibiting inflammation and ferroptosis via regulating the Nrf2 signaling pathway.IMPORTANCEEndometritis is an inflammatory disease of the endometrium, which is a common gynecological disease. Up to now, there is no evidence for the protective effects of luteolin on endometritis. The purpose of this study was to investigate whether luteolin has protective effects against S. aureus-induced endometritis and attempts to clarify the mechanism.

Emerging bacterial factors for understanding pathogenesis of endometriosis

The pathogenesis of endometriosis is a complex process, and recent research has introduced novel hypotheses in this field. This review summarizes recent studies on the pathogenesis of endometriosis. We focused on several classical hypotheses, as well as their interactions with the microenvironment of hormonal dependence and immunosuppression. Furthermore, we highlighted the emergence of bacterial factors associated with endometriosis. Recent advances in next-generation sequencing (NGS) have revealed the presence and detailed distribution of these bacteria as well as the involvement of specific bacteria in pathogenesis. These factors alter the microenvironment in the early stages of endometriosis development, leading to lesion formation. Understanding the mechanisms underlying the early development of endometriosis from a new perspective would be helpful for the development of novel therapeutic agents for endometriosis.

Downregulation of pattern recognition receptors on macrophages involved in aggravation of endometriosis

PROBLEM

In women of reproductive age, endometriosis may contribute to dysmenorrhea, chronic pelvic pain, dyspareunia, infertility, adenomyosis, and endometrial ovarian cyst (EOC). Recent studies have shown that chronic inflammation occurs in the pelvis of endometriosis patients and that this inflammation is exacerbated by immunosuppression, leading to survival endometrial debris. However, the detailed immunological mechanisms underlying the aggravation of inflammation and immunosuppression in endometriosis patients remain unclear.

METHOD OF STUDY

We investigate the alarmins (high-mobility group box-1, IL-33, IL-1α, and S100B protein), proinflammatory cytokines (IL-6 and IL-1β), and immune cells (CD8+ T cells, CD4+ T cells, natural killer cells, natural killer T cells, dendritic cells, and macrophages) in peritoneal fluid of patients with EOC using enzyme-linked immunosorbent assay, electrochemiluminescence, and flow cytometry. Then, we analyzed the correlation between these factors and the aggravating indicators of endometriosis, tumor size and revised American Society for Reproductive Medicine (r-ASRM) score.

RESULTS

Unexpectedly, there was no correlation between each alarmin level and aggravating indicators. However, the expression of pattern recognition receptors, toll-like receptor 4, and receptor of advanced glycation end-products on macrophages was inversely correlated with aggravating indicators.

CONCLUSIONS

The aggravation of endometriosis is associated with a decrease in alarmin receptors but not alarmin levels. Investigation of innate immune systems, such as alarmins and their receptors, may help elucidate new mechanisms of endometriosis.

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.

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.

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

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

Endometriosis and gynaecological cancers: molecular insights behind a complex machinery

Endometriosis is described as the presence of both endometrial glandular and stromal cells outside the uterine cavity. A major characterization of this disease is ectopic implantation of endometrial cells with increased migration. It is one of the leading causes of morbidity among premenopausal women, with a prevalence of 10-16% of women of reproductive age. Despite over century of intensive research, none of the current treatment options represents a real cure. Based on the current knowledge, endometriosis, particularly its atypical version, is considered to be a transitional form from benign disease to tumour. However, the exact mechanisms of this conversion are still not fully established.

Circulating miRNAs Related to Epithelial-Mesenchymal Transitions (EMT) as the New Molecular Markers in Endometriosis

Endometriosis is a chronic gynecological disease defined by the presence of endometrial-like tissue found outside the uterus, most commonly in the peritoneal cavity. Endometriosis lesions are heterogenous but usually contain endometrial stromal cells and epithelial glands, immune cell infiltrates and are vascularized and innervated by nerves. The complex etiopathogenesis and heterogenity of the clinical symptoms, as well as the lack of a specific non-invasive diagnostic biomarkers, underline the need for more advanced diagnostic tools. Unfortunately, the contribution of environmental, hormonal and immunological factors in the disease etiology is insufficient, and the contribution of genetic/epigenetic factors is still fragmentary. Therefore, there is a need for more focused study on the molecular mechanisms of endometriosis and non-invasive diagnostic monitoring systems. MicroRNAs (miRNAs) demonstrate high stability and tissue specificity and play a significant role in modulating a range of molecular pathways, and hence may be suitable diagnostic biomarkers for the origin and development of endometriosis. Of these, the most frequently studied are those related to endometriosis, including those involved in epithelial–mesenchymal transition (EMT), whose expression is altered in plasma or endometriotic lesion biopsies; however, the results are ambiguous. Specific miRNAs expressed in endometriosis may serve as diagnostics markers with prognostic value, and they have been proposed as molecular targets for treatment. The aim of this review is to present selected miRNAs associated with EMT known to have experimentally confirmed significance, and discuss their utility as biomarkers in 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 Is Associated with Functional Polymorphism in the Promoter of Heme Oxygenase 1 (HMOX1) Gene

Endometriosis is a common gynecological disorder characterized by the ectopic growth of endometrial-like tissue outside the uterine cavity. Etiopathogenesis of endometriosis is poorly understood; it is plausible, however, that the disease may be associated with oxidative stress related to local heme and iron metabolism. Therefore, the aim of the study was to reveal a possible association of endometriosis with a stress-inducible heme oxygenase 1 (HMOX1). For this purpose, 228 patients with clinically confirmed endometriosis and 415 control parous women from general Polish population were examined for functional -413A>T (rs2071746) single-nucleotide polymorphism (SNP) and (GT)_n dinucleotide repeat length polymorphism in the promoter of HMOX1 gene. In addition, -413A>T SNP was assessed by the specific TaqMan^® SNP Genotyping Assay, and (GT)_n polymorphism was determined by PCR product size analysis. We found that endometriosis is associated with an increased frequency of -413A(GT)_31,32 haplotype (OR (95%CI) = 1.27 (1.01-1.60), p = 0.0381) and -413A(GT)_31,32 homozygous genotype [OR (95%CI) = 1.51 (1.06-2.17), p = 0.0238]. These data suggest that endometriosis is associated with functional polymorphism of HMOX1 gene, and this gene may play a part in the pathogenesis of this disorder.

Inflammation related to high-mobility group box-1 in endometrial ovarian cyst

Endometriosis is a chronic inflammatory disease often associated with dysmenorrhea, infertility, adenomyosis, and endometrial ovarian cyst (EOC). In particular, EOC can sometimes become malignant in a longitudinal follow-up. This study aimed to investigate the involvement of high-mobility group box-1 (HMGB1) in an inflammatory milieu and the characteristics of immune cells in EOC. The samples were obtained from patients who underwent ovarian cystectomy for benign ovarian cyst. The participants were divided into two groups: patients with EOC (EOC group) and those without EOC (nEOC group). We divided a part of the removed ovary into small sections and isolated the tissue cells. Thereafter, the cytoplasmic HMGB1 levels in DCs, macrophages, and non-immune cells were analyzed by flow cytometry. We also evaluated the proportions of immune, T, NK, iNKT, NK, and regulatory T (Treg) cells. Results showed that the DCs, macrophages, and non-immune cells of EOC had significantly higher cytoplasmic HMGB1 levels than those of nEOC. The expression of CD69 and CD107a on CD8⁺ T and CD4⁺ T cells of EOC was also more enhanced than that of nEOC. Furthermore, the M2 macrophages and Tregs highly accumulated in EOC. These results indicate that HMGB1 may aggravate chronic inflammation related to T-cell activation and simultaneously facilitate development of the immunosuppressive milieu in EOCs.

HMGB1 Mediated Inflammation and Autophagy Contribute to Endometriosis

AIM

High 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.

METHODS

Endometrial 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.

RESULTS

Positive 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.

CONCLUSION

Knockdown 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.

Pain in Endometriosis

Endometriosis is a chronic and debilitating condition affecting ∼10% of women. Endometriosis is characterized by infertility and chronic pelvic pain, yet treatment options remain limited. In many respects this is related to an underlying lack of knowledge of the etiology and mechanisms contributing to endometriosis-induced pain. Whilst many studies focus on retrograde menstruation, and the formation and development of lesions in the pathogenesis of endometriosis, the mechanisms underlying the associated pain remain poorly described. Here we review the recent clinical and experimental evidence of the mechanisms contributing to chronic pain in endometriosis. This includes the roles of inflammation, neurogenic inflammation, neuroangiogenesis, peripheral sensitization and central sensitization. As endometriosis patients are also known to have co-morbidities such as irritable bowel syndrome and overactive bladder syndrome, we highlight how common nerve pathways innervating the colon, bladder and female reproductive tract can contribute to co-morbidity via cross-organ sensitization.

Endometriosis and irritable bowel syndrome: a systematic review and meta-analysis

PURPOSE

Irritable bowel disease and endometriosis are two common diseases characterized by chronic inflammation state and recurrent abdominal pain. As a consequence of sharing of symptoms and chronic inflammation, endometriosis and IBS may coexist and be misdiagnosed and this leads to delays in diagnosis, mismanagement, and unnecessary testing. In recent years, some studies have found higher risk of IBS in women with endometriosis, compared to women without endometriosis. To provide a general overview, we performed a systematic review and a meta-analysis on published data on this issue.

METHODS

By a systematic literature search selection process, 11 studies were identified for the current study: 2 prospective and 2 retrospective cohort studies, 4 case-control studies, 1 cross-sectional study and 2 clinical series.

RESULTS

When we meta-analysed data about the prevalence of IBS in women with endometriosis, the overall OR (95%CI), compared to women without endometriosis was 3.26 (1.97-5.39) with no statistically significant heterogeneity. All three studies considering the incidence of IBS in women with a previous diagnosis of endometriosis showed about twofold greater risk among women with endometriosis than women without. Likewise, in the random effects model of the meta-analysis, the overall OR of history of IBS in women with endometriosis was 3.10 (95% CI 2.06-4.67), with no heterogeneity between three studies considered.

CONCLUSION

This meta-analysis provides epidemiological evidence of a link between endometriosis and IBS, highlighting two or more times higher risk of IBS in women with endometriosis compared to women without the condition.

Harmful and beneficial effects of inflammatory response on reproduction: sterile and pathogen-associated inflammation

In reproduction, inflammatory processes play important roles in the development of many pregnancy complications such as preterm labor/birth, recurrent pregnancy loss, recurrent implantation failure, and preeclampsia. Inflammation can be initiated by both microbial and non-microbial causes. Bacterial infection in the feto-maternal interface and uterus can provoke preterm labor/birth, miscarriage, and chronic endometritis. By contrast, inflammation without infection, or 'sterile inflammation,' can also lead to many kinds of complications, such as preterm labor/birth, miscarriage, or preeclampsia. Aberrant inflammation is facilitated by immune cells such as macrophages, dendritic cells, natural killer cells, and invariant natural killer T cells. In addition, cytokines, chemokines, and several kinds of inflammatory mediators are involved. On the other hand, appropriate inflammation is required for a successful offspring during the progression of the entire pregnancy. Herein, we discuss the relation between pregnancy and inflammation with immunological alterations. Understanding the role of inflammation in complications during pregnancy may establish new perspectives of the progress of normal pregnancy as well as treatments during pregnancy complications.

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

Recent evidence suggests that immunological aspects play a pivotal role in this disorder. Toll-like receptor 2 (TLR2) is crucial in recognizing microbial infections and mediating innate immune response. The objective of our study was to rate with flow cytometry the levels of several subsets of dendritic cells, monocytes, and basic peripheral blood lymphocytes expressing TLR2, aiming at the determination of a possible correlation between the expression of TLR2 and the clinical outcomes of endometriosis in 40 patients and 40 age-matched healthy women. Our study showed the importance of TLR2 expression, mainly on myeloid dendritic cells (mDCs) and B cells in patients with endometriosis. Both mDCs BDCA1+CD19-TLR2+ and B lymphocytes CD19+TLR-2+ proved useful in the differentiation of affected individuals with stages 3–4 of the disease (area under the receiver operating characteristic curve /AUC/ = 0.96, p < 0.0001 for mDCs; AUC = 0.78, p = 0.0001 for B lymphocytes), and those presenting adhesion (AUC = 0.92, p < 0.0001 for mDCs; AUC = 0.82, p < 0.0001 for B lymphocytes) or infertility (AUC = 0.83, p < 0.0001 for mDCs; AUC = 0.73, p = 0.006 for B lymphocytes). Our findings suggest that the levels of TLR2-expressing cells, particularly mDCs and B lymphocytes, may be an effective biomarker of endometriosis, because the disease currently lacks clinically useful noninvasive biomarkers enabling early and cost-effective diagnosis.

Endometriosis - a decade later - still an enigmatic disease. What is the new in the diagnosis and treatment?

Endometriosis is a common disease in women of reproduction age. It causes pain and difficulty in getting pregnant. However the exact causes of infertility associated with endometriosis still remain controversial. The treatment of endometriosis consists of medical treatment of pain as well as medical and surgical treatment of infertility caused by endometriosis and assisted reproduction techniques. Since the treatment of endometriosis is often connected with diminishing ovarian reserve, the techniques for ovarian tissue preservation and oocyte and embryo freezing are used to maintain the ability for childbearing.

The feasibility of the platelet count and mean platelet volume as markers of endometriosis and adenomyosis: A case control study

INTRODUCTION

The aim of the study is to investigate the role of platelet count (PC) and mean platelet volume (MPV) in determining adenomyosis and endometriosis.

MATERIAL AND METHODS

This was a retrospective case control study that included adenomyosis, endometriosis and control groups. The adenomyosis group included 84 women diagnosed between January 2013 and January 2015 based on hysterectomy specimen. The endometriosis group included 102 patients underwent diagnostic laparoscopy and confirmed by histopathologic examination. Lastly, the control group included 88 women had no medical problem and underwent tubal ligation.

RESULTS

MPV (fl) was significantly lower in adenomyosis group (8.5) compared to endometriosis (9, p<0.05) and control groups (9, p<0.01). Modified platelet activity (MPV/PC) was significantly lower in adenomyosis group compared to control group (p<0.01). Bivariate logistic regression model was used to assess the odds ratio of risk factors and serum markers related to endometriosis and adenomyosis. Variables showing significant differences based on post-hoc Bonferroni test were included in the logistic regression model for comparison of each disease with the control group. MPV was not found to be a risk factor both for presence of endometriosis and adenomyosis after adjusting for demographic and clinical characteristics.

DISCUSSION

Our study suggested that PC and MPV were not useful diagnostic markers for endometriosis or adenomyosis. Further research on how platelet indices and other inflammatory markers are related to inflammation might help better understand their potential as markers for these diseases.

Elevated urine histone 4 levels in women with ovarian endometriosis revealed by discovery and parallel reaction monitoring proteomics

Endometriosis is a common gynecologic disorder and due to a lack of non-invasive detection methods, it can take up to 12 years before an affected woman obtains a diagnosis and receives appropriate treatment. Therefore, the identification of a specific biomarker that can be detected quickly and non-invasively is urgently needed. In this study, the urine proteome, a potentially rich source of biomarkers, is examined in patients with or without endometriosis in an attempt to identify novel protein biomarkers that can be used to diagnose endometriosis. This study is the first to combine tandem mass tags and parallel reaction monitoring approaches to aid in identifying and validating urine biomarkers for endometriosis. The findings presented herein support previous conclusions that endometriosis is a chronic inflammatory disease. Additionally, Histone 4 was identified as a potential biomarker and/or therapeutic target for endometriosis. At a cutoff of 14.2, the area under the curve for H4 was 0.848, with a sensitivity of 70% and specificity of 80%. Moreover, to our knowledge, this is the first study to observe an elevated histone level in body fluids obtained from endometriosis patients. While this study provides a good foundation, further studies are required to further validate the results presented. SIGNIFICANCE: Endometriosis is a common gynecologic disorder and due to a lack of non-invasive detection methods, it can take up to 12 years before an affected woman obtains a diagnosis and receives appropriate treatment. Therefore, the identification of a specific biomarker that can be detected quickly and non-invasively is urgently needed. We believe our results have an important impact on detection and treatment of endometriosis. Firstly, this study is the first to combine tandem mass tags and parallel reaction monitoring approaches to aid in identifying and validating urine biomarkers for endometriosis, which has established the methodology required for subsequent studies. Secondly, this is also the first study to observe an elevated histone level in body fluids obtained from endometriosis patients. Compared with other urine biomarkers reported in literature, histone 4 has a potential to serve as a biomarker of endometriosis and a therapeutic target. Thirdly, our study supports previous conclusions that endometriosis is a chronic inflammatory disease. These findings can warrant further investigation of the pathophysiology of endometriosis.

Sphingosine 1 Phosphate (S1P) Increased IL-6 Expression and Cell Growth in Endometriotic Cells

OBJECTS

There is growing evidence that sphingosine 1-phosphate (S1P) is involved in inflammatory diseases. As endometriosis is known as an inflammatory disease, we investigated the role of S1P system in the development of endometriosis.

METHODS

The expression of sphingosine kinase (SphK) 1 in endometriosis lesions was examined by immunohistochemistry. The cystic fluid of ovarian cysts/tumors were obtained to measure S1P concentrations. Endometriotic stromal cells (ESC) derived from endometrioma were used for in vitro experiments.

RESULTS

Sphingosine kinase 1 was detected in epithelium and stromal cells of endometriotic lesions. The mean S1P concentration in the cystic fluid of endometriomas was higher than that in nonendometriomas significantly (98.2 nM vs less than 1.5 nM, P < .01). Interleukin-1β (IL-1β) or transforming growth factor-β exhibited 2.7-fold and 11.5-fold increase in SphK1 messenger RNA (mRNA) expression in ESC, respectively (P < .01). Higher dose of S1P (125nM) increased the cell number of ESC by 20%, and low dose of S1P (1.25 nM and 12.5 nM) induced IL-6 mRNA production and IL-6 secretion by ESC dose-dependently. JTE013, an antagonist for S1PR2, partially suppressed IL-6 induction by S1P (P < .05). JTE013 and VPC23019, an antagonist for S1PR1 and S1PR3, suppressed the ESC proliferation induced by S1P.

CONCLUSION

The present study for the first time proved that the SphK-S1P-S1PR axis play a role of accelerating inflammation and growth of endometriotic cells.

A novel and compact review on the role of oxidative stress in female reproduction

In recent years, the study of oxidative stress (OS) has become increasingly popular. In particular, the role of OS on female fertility is very important and has been focused on closely. The occurrence of OS is due to the excessive production of reactive oxygen species (ROS). ROS are a double-edged sword; they not only play an important role as secondary messengers in many intracellular signaling cascades, but they also exert indispensable effects on pathological processes involving the female genital tract. ROS and antioxidants join in the regulation of reproductive processes in both animals and humans. Imbalances between pro-oxidants and antioxidants could lead to a number of female reproductive diseases. This review focuses on the mechanism of OS and a series of female reproductive processes, explaining the role of OS in female reproduction and female reproductive diseases caused by OS, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia and so on. Many signaling pathways involved in female reproduction, including the Keap1-Nrf2, NF-κB, FOXO and MAPK pathways, which are affected by OS, are described, providing new ideas for the mechanism of reproductive diseases.

Novel Hybrid Conjugates with Dual Suppression of Estrogenic and Inflammatory Activities Display Significantly Improved Potency against Breast Cancer

In this work, we developed a small library of novel OBHS-RES hybrid compounds with dual inhibition activities targeting both the estrogen receptor α (ERα) and NF-κB by incorporating resveratrol (RES), a known inhibitor of NF-κB, into a privileged indirect antagonism structural motif (OBHS, oxabicycloheptene sulfonate) of estrogen receptor (ER). The OBHS-RES conjugates could bind well to ER and showed remarkable ERα antagonistic activity, and they also exhibited excellent NO inhibition in macrophage RAW 264.7 cells. Compared with 4-hydroxytamoxifen, some of them showed better antiproliferative efficacy in MCF-7 cell lines with IC₅₀ up to 3.7 μM. In vivo experiments in a MCF-7 breast cancer model in Balb/c nude mice indicated that compound 26a was more potent than tamoxifen. Exploration of the compliancy of the structure against ER specificity utilizing these types of isomeric three-dimensional ligands indicated that one enantiomer had much better biological activity than the other.

Local and systemic levels of cytokines and danger signals in endometriosis-affected women

Endometriosis is a prevalent gynaecological disorder with a still unclear pathogenesis. So far inflammatory mechanisms are associated with disease progression and critical reviews have discussed the so-called 'danger theory' related to endometriosis. Hence, we performed immunoassays to evaluate whether local inflammation is linked to the severity of the disease. In addition, we investigated the role of recently described cytokines IL-33, IL-32α and the 'alarmin' high mobility group box 1 (HMGB1). We confirmed a dysfunctional immune response in the local environment of women suffering from endometriosis. However, we found no direct evidence for a significant up-regulation of danger signals in endometriosis, irrespective of the severity of the disease.

Bacterial contamination hypothesis: a new concept in endometriosis

Background

Endometriosis is a multifactorial disease that mainly affects women of reproductive age. The exact pathogenesis of this disease is still debatable. The role of bacterial endotoxin (lipopolysaccharide, LPS) and Toll-like receptor 4 (TLR4) in endometriosis were investigated and the possible source of endotoxin in the pelvic environment was examined.

Methods

The limulus amoebocyte lysate test was used to measure the endotoxin levels in the menstrual fluid and peritoneal fluid and their potential role in the growth of endometriosis was investigated. Menstrual blood and endometrial samples were cultured for the presence of microbes. The effect of gonadotrophin-releasing hormone agonist (GnRHa) treatment on intrauterine microbial colonization (IUMC) and the occurrence of endometritis was investigated.

Main findings Results

Lipopolysaccharide regulates the pro-inflammatory response in the pelvis and growth of endometriosis via the LPS/TLR4 cascade. The menstrual blood was highly contaminated with Escherichea coli and the endometrial samples were colonized with other microbes. A cross-talk between inflammation and ovarian steroids or the stress reaction also was observed in the pelvis. Treatment with GnRHa further worsens intrauterine microbial colonization, with the consequent occurrence of endometritis in women with endometriosis.

Conclusion

For the first time, a new concept called the "bacterial contamination hypothesis" is proposed in endometriosis. This study's findings of IUMC in women with endometriosis could hold new therapeutic potential in addition to the conventional estrogen-suppressing agent.

Early Endometriosis in Females Is Directed by Immune-Mediated Estrogen Receptor α and IL-6 Cross-Talk

Endometriosis is a gynecological disease that negatively affects the health of 1 in 10 women. Although more information is known about late stage disease, the early initiation of endometriosis and lesion development is poorly understood. Herein, we use a uterine tissue transfer mouse model of endometriosis to examine early disease development and its dependence on estradiol (E2) and estrogen receptor (ER) α within 72 hours of disease initiation. Using wild-type and ERα knockout mice as hosts or donors, we find substantial infiltration of neutrophils and macrophages into the peritoneal cavity. Examining cell infiltration, lesion gene expression, and peritoneal fluid, we find that E2/ERα plays a minor role in early lesion development. Immune-mediated signaling predominates E2-mediated signaling, but 48 hours after the initiation of disease, a blunted interleukin (IL)-6-mediated response is found in developing lesions lacking ERα. Our data provide evidence that the early initiation of endometriosis is predominantly dependent on the immune system, whereas E2/ERα/IL-6-mediated cross-talk plays a partial role. These findings suggest there are two phases of endometriosis-an immune-dependent phase and a hormone-dependent phase, and that targeting the innate immune system could prevent lesion attachment in this susceptible population of women.

Bradykinin system is involved in endometriosis-related pain through endothelin-1 production

BACKGROUND

Endometriosis is a gynaecological disease exhibiting severe pelvic pain, but the mechanism of pain production remains unknown. Bradykinin (BK) is known as an inflammatory mediator, and shows elevated levels in inflammatory diseases such as rheumatoid arthritis. In the present study, we evaluated whether BK is involved in endometriosis-related pain.

METHODS

Endometriotic lesions were used for immunohistochemistry. Primary cultures of endometriotic stromal cells (ESC) were stimulated with IL-1β and/or BK. Quantitative RT-PCR was used to evaluate the mRNA expressions of BK receptors (BKR) and endothelin-1 in ESC. The concentration of endothelin-1 in cystic fluid of endometrioma or non-endometrioma was measured with ELISA. The conditioned medium of ESC stimulated with IL-1β and/or BK was injected intraplantarly in mice, and evaluated whether pain-related licking behaviour was elicited.

RESULTS

The expressions of BK and BKR in endometriotic lesions were observed by immunohistochemistry. In vitro experiments showed that IL-1β induced BKR-B1 and B2 on ESC. Activation of these receptors by BK significantly induced endothelin-1 expression in ESC, which was negated completely by HOE-140, a BKR-B2 antagonist. The cystic fluid of endometrioma contained higher amount of endothelin-1 compared to non-endometrioma. Intraplantar injection of the conditioned medium of ESC treated with IL-1β and BK significantly induced licking behaviour, which was suppressed with BQ-123, an endothelin type-A receptor antagonist.

CONCLUSIONS

The present study demonstrated the presence and the function of the BK axis in endometriosis, and established a potential new therapy target for endometriosis-related pain.

SIGNIFICANCE

The present study demonstrated (1) the presence and the function of the BK system in endometriosis, (2) activation of BKR induced endothelin-1 in endometriotic lesion and (3) blocking endothelin-1 was effective to decrease pain.

Oxidative Stress and Endometriosis: A Systematic Review of the Literature

Endometriosis is one of the most common gynaecologic diseases in women of reproductive age. It is characterized by the presence of endometrial tissue outside the uterine cavity. The women affected suffer from pelvic pain and infertility. The complex etiology is still unclear and it is based on three main theories: retrograde menstruation, coelomic metaplasia, and induction theory. Genetics and epigenetics also play a role in the development of endometriosis. Recent studies have put the attention on the role of oxidative stress, defined as an imbalance between reactive oxygen species (ROS) and antioxidants, which may be implicated in the pathophysiology of endometriosis causing a general inflammatory response in the peritoneal cavity. Reactive oxygen species are intermediaries produced by normal oxygen metabolism and are inflammatory mediators known to modulate cell proliferation and to have deleterious effects. A systematic review was performed in order to clarify the different roles of oxidative stress and its role in the development of endometriosis. Several issues have been investigated: iron metabolism, oxidative stress markers (in the serum, peritoneal fluid, follicular fluid, peritoneal environment, ovarian cortex, and eutopic and ectopic endometrial tissue), genes involved in oxidative stress, endometriosis-associated infertility, and cancer development.

Effect of interleukin-1β and lipoxin A4 in human endometriotic stromal cells: Proteomic analysis

AIM

Lipoxin A₄ (LXA₄ ) can function as an endogenous 'breaking signal' in inflammation and plays an important role in the progression of endometriosis. The proteome responses to interleukin-1β (IL-1β) or LXA₄ in human endometriotic stromal cells (ESC) are not well understood.

METHODS

In this study, primary ESC were cultured from ovarian endometriosis tissue. Three groups were established: the control group; the IL-1β stimulation group; and the IL-1β and LXA₄ incubation group. Proteins were assessed on 2-D polyacrylamide gel electrophoresis (2D-PAGE), and differentially expressed protein spots were further identified on matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MALDI-TOF-MS). Wound healing and transwell assays were performed to assess the migration and invasion of ESC after treatment.

RESULTS

In total, 40 differentially expressed protein spots were identified successfully on MALDI-TOF-MS. The proteins identified were related to cell structure, metabolism, signal transduction, protein synthesis and membrane structure, processes that may be involved in the development of endometriosis. Vinculin and IL-4 were further analyzed on western blot and quantitative real-time polymerase chain reaction. Moreover, LXA₄ could suppress the migration and invasion of ESC induced by IL-1β.

CONCLUSION

LXA₄ may inhibit the progression of endometriosis partly by lowering or raising the effect of IL-1β, mediated via some inflammation-related proteins (e.g. vinculin) and immune response-related protein (e.g. IL-4) in vitro.

Phosphoproteomics Analysis of Endometrium in Women with or without Endometriosis

Background:

The molecular mechanisms underlying the endometriosis are still not completely understood. In order to test the hypothesis that the approaches in phosphoproteomics might contribute to the identification of key biomarkers to assess disease pathogenesis and drug targets, we carried out a phosphoproteomics analysis of human endometrium.

Methods:

A large-scale differential phosphoproteome analysis, using peptide enrichment of titanium dioxide purify and sequential elution from immobilized metal affinity chromatography with linear trap quadrupole-tandem mass spectrometry, was performed in endometrium tissues from 8 women with or without endometriosis.

Results:

The phosphorylation profiling of endometrium from endometriosis patients had been obtained, and found that identified 516 proteins were modified at phosphorylation level during endometriosis. Gene ontology annotation analysis showed that these proteins were enriched in cellular processes of binding and catalytic activity. Further pathway analysis showed that ribosome pathway and focal adhesion pathway were the top two pathways, which might be deregulated during the development of endometriosis.

Conclusions:

That large-scale phosphoproteome quantification has been successfully identified in endometrium tissues of women with or without endometriosis will provide new insights to understand the molecular mechanisms of the development of endometriosis.

Increased Risk of Endometriosis in Patients With Lower Genital Tract Infection: A Nationwide Cohort Study

Endometriosis results from the ectopic invasion of endometrial glands and stroma in the peritoneal cavity. The exact etiology of endometriosis is still unknown. It has, however, been shown that there are higher numbers of Escherichia coli in menstrual blood, and higher endotoxin levels in menstrual fluid, as well as, in the peritoneal fluid of patients with endometriosis. In this study, we aimed to determine whether lower genital tract infections could increase the risk of endometriosis.We used the Taiwan National Health Insurance database to conduct a population-based cohort study. We included patients diagnosed with inflammatory diseases of the cervix, vagina, and vulva, and a control group comprising patients matched by age, sex, and comorbidities but without inflammatory diseases of the cervix, vagina, or vulva.A total of 79,512 patients were included in the inflammatory disease group and an equal number of control individuals were selected. The incidence of endometriosis (hazard ratio, 2.01; 95% confidence interval, 1.91-2.12; P < 0.001) was higher among patients than controls. Cox proportional hazards models showed that irrespective of comorbidities, lower genital tract infection was an independent risk factor for endometriosis.Patients with lower genital tract infections exhibit a substantially higher risk for developing endometriosis.

LPS/TLR4-mediated stromal cells acquire an invasive phenotype and are implicated in the pathogenesis of adenomyosis

The present study tested whether the LPS/TLR4 signal pathway in endometrial stromal cells is essential for the pathogenesis of adenomyosis. We tested the expression of TLR4, MD2 in the endometrium without adenomyosis (CE), the eutopic endometrium with adenomyosis (EuE) and the ectopic endometrium with adenomyosis (EE). We isolated the stromal cells from CE, EuE and EE (CESC, EuESC, EESC), treated with lipopolysaccharide (LPS) and TLR4 antagonist and detected the cell viability. And we also measured the key protein of the TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells. We found that the viability of experimental cells treated with LPS was significantly greater than that of the non-treated cells, blocked by the TLR4 antagonist VIPER. TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells stimulated by LPS, and it was inhibited by VIPER. This study suggested that stromal cells were activated by the TLR4 signalling pathway, which processed the cellular inflammatory proliferation and invasive growth involved in the pathogenesis of adenomyosis.

The risk of irritable bowel syndrome in patients with endometriosis during a 5-year follow-up: a nationwide population-based cohort study

PURPOSE

Studies have suggested that endometriosis may coexist with irritable bowel syndrome (IBS). Using a population-based cohort study, we followed subjects for a 5-year period to identify the risk of IBS after a diagnosis of endometriosis.

METHODS

This cohort study used the Taiwan National Health Insurance Database as a source of subjects. A total of 6076 patients with endometriosis from 2000 to 2005 were identified. Their data were compared with those of 30,380 age-matched controls without endometriosis who were randomly selected from the same database. All subjects were tracked for 5 years from the date of cohort entry to identify the risk of IBS. The Cox model was used to evaluate the 5-year event occurrence of IBS.

RESULTS

Nine hundred twenty-six patients were diagnosed with IBS, including 256 in the case cohort (4.2%) and 670 in the control cohort (2.2%). The Kaplan-Meier survival curves demonstrated significantly lower event-free rates in the case cohort than in the control cohort (P = 0.001). After adjusting for urbanization level, monthly income, residential region and comorbidities, the hazard ratio (HR) within 5 years revealed a 1.79-fold (95% confidence interval [CI] 1.55-2.07) greater risk among the cases than the controls. The HR was higher within the first year of follow-up (HR 1.90, 95% CI 1.42-2.55) and in those women aged 25-34 years (HR 2.17, 95% CI 1.61-2.92).

CONCLUSIONS

The risk of IBS among endometriosis patients persisted over 5 years of follow-up. The association detected in this study might have proceeded through shared risk and pathogenic factors.

The Impact of Endometriosis across the Lifespan of Women: Foreseeable Research and Therapeutic Prospects

In addition to estrogen dependence, endometriosis is characterized by chronic pelvic inflammation. The impact of the chronic pelvic inflammatory state on other organ systems and women's health is unclear. Endometriosis associated chronic inflammation and potential adverse health effects across the lifespan render it imperative for renewed research vigor into the identification of novel biomarkers of disease and therapeutic options. Herein we propose a number of opportunities for research and development of new therapeutics to address the unmet needs in the treatment of endometriosis per se and its ancillary risks for other diseases in women across the lifespan.

Endometriotic mesenchymal stem cells exhibit a distinct immune phenotype

Endometriosis is a significant debilitating gynecological problem affecting women of the reproductive age group and post-menopause. Recent reports suggest a role for endometriotic mesenchymal stem cells (ectopic MSCs) in the pathogenesis of endometriosis. To investigate the plausible mechanisms leading to the pathogenic behavior of ectopic MSCs, we compared the immunomodulatory properties of eutopic (healthy) and ectopic MSCs. We analyzed MSC phenotypes, differentiation potential, differential gene expression for an array of pattern recognition receptors (PRRs) and pro-inflammatory cytokine release along with markers of migration and angiogenesis among eutopic and ectopic MSCs. Further, alterations in immunosuppressive functions of eutopic and ectopic MSCs were examined by co-culturing them with mitogen-activated allogeneic PBMCs. Transcripts of PRRs such as all Toll-like receptors (TLR1–10), except TLR8, collectins (CL-L1, CL-P1 and CL-K1), NOD-1 and NOD-2 receptors and secreted pro-inflammatory cytokines like IL-6, IFN-γ, vascular endothelial growth factor (VEGF), epidermal growth factor and MCP-1 were significantly up-regulated in ectopic MSCs. The anti-inflammatory cytokine transforming growth factor-β showed significant down-regulation, while IL-10 showed a significant increase in ectopic MSCs. Further, ectopic MSCs showed up-regulated expression for markers of migration and angiogenesis such as matrix metalloproteinase-2 (MMP-2), MMP-3 and MMP-9 and VEGF, respectively. We report here that proliferation of PBMCs was less inhibited upon co-culture with ectopic MSCs compared with eutopic MSCs. The findings suggest that ectopic MSCs with increased levels of TLRs, collectins, pro-inflammatory cytokines and markers of migration and angiogenesis exhibit a distinct immune phenotype compared to eutopic MSCs. This distinct phenotype may be responsible for the reduced immunosuppressive property of ectopic MSCs and may be associated with the pathogenesis of endometriosis.

Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis

The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.

Endometriosis, leiomyoma and adenomyosis: the risk of gynecologic malignancy

The aim of this review article was to evaluate the relationship and the possible etiological mechanisms between endometriosis, leiomyoma (LM) and adenomyosis and gynecological cancers, such as ovarian and endometrial cancer and leiomyosarcoma (LMS). MEDLINE was searched for all articles written in the English literature from July 1966 to May 2013. Reports were collected systematically and all the references were also reviewed. Malignant transformation of gynecologic benign diseases such as endometriosis, adenomyosis and LM to ovarian and endometrial cancer remains unclear. Hormonal factors, inflammation, familial predisposition, genetic alterations, growth factors, diet, altered immune system, environmental factors and oxidative stress may be causative factors in carcinogenesis. Early menarche, low parity, late menopause and infertility have also been implicated in the pathogenesis of these cancers. Ovarian cancers and endometriosis have been shown to have common genetic alterations such as loss of heterozygosity (LOH), PTEN, p53, ARID1A mutations. MicroRNAs have also been implicated in malignant transformation. Inflammation releases proinflammatory cytokines, and activates tumor associated macrophages (TAMS) and nuclear factor kappa b (NF-KB) signaling pathways that promote genetic mutations and carcinogenesis. MED12 mutations in LM and smooth muscle tumors of undetermined malignant potential (STUMP) may contribute to malignant transformation to LMS. A hyperestrogenic state may be shared in common with pathogenesis of adenomyosis, LM and endometrial cancer. However, the effect of these benign gynecologic diseases on endometrial cancer should be studied in detail. This review study indicates that endometriosis, LM, adenomyosis may be associated with increased risk of gynecological cancers such as endometrial and ovarian cancers. The patients who have these gynecological benign diseases should be counseled about the future risks of developing cancer. Further studies are needed to investigate the relationship between STUMPs, LMS and LM and characteristics and outcome endometrial carcinoma in adenomyotic patients.

Can platelet indices be new biomarkers for severe endometriosis?

Objective. The aim of this study was to investigate whether platelet indices-mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) would be useful as noninvasive biomarkers for determining the severity of endometriosis. Methods. A retrospective review of the medical charts of 164 patients diagnosed with endometriosis and who were operated on between 2001 and 2013 was performed. The stage of endometriosis was determined according to revised American Society for Reproductive Medicine criteria. Results. In patients with advanced endometriosis (Stages 3-4), PLT, PCT levels were found to be significantly higher and MPV, PDW values to be significantly lower when compared to initial endometriosis (Stages 1-2). In addition, there was a significant positive correlation between PLT (r: 0.800, P: 0.001) and PCT (r: 0.727, P: 0.002) and the inflammatory marker white blood cell count (WBC). Conclusion. Our finding may not sufficient for employing platelet indices solely in this differential diagnosis, but our finding could provide a suggestion for clinical physicians so that attention is paid to the value of platelet indices and that these may be taken into account when making decisions about the initial or advanced stages of endometriosis.

Differential TGFB1-Signalling in Endometrium from Women with Endometriosis: Importance of Appropriate Housekeeping Genes

Purpose

Endometriosis is characterised by inflammation, fibrosis and scarring, all processes known to involve transforming growth factor-β1 (TGFB1). We examined the expression of genes involved in TGFB1 signalling in epithelium and stroma from eutopic versus ectopic endometrium in women with endometriosis.

Methods

Eutopic and ectopic endometrium was collected during laparoscopy from women with endometriosis (n = 4 proliferative, n = 7 secretory). Laser capture microdissection was used to collect glandular epithelium and CD10-positive stroma from ectopic lesions and eutopic endometrium. Quantitative real-time RT-PCR was used to examine TGFB1, SMAD family member-2 (SMAD2), SMAD3 and SMAD4 mRNA. Expression of mRNA was relative to an RNA-spike. B2M and RPL13A mRNA, and 18S rRNA were also examined; however, expression varied between eutopic and ectopic sites making them unsuitable housekeeping genes in this model.

Results

TGFB1, SMAD3 and SMAD4 mRNA expression was significantly higher in eutopic versus ectopic glandular epithelium; SMAD3 expression was significantly higher in secretory versus proliferative phase eutopic epithelium. TGFB1 expression was significantly higher in eutopic versus ectopic stroma.

Conclusions

Variations in TGFB1, SMAD3 and SMAD4 mRNA expression in eutopic relative to ectopic tissues are consistent with a specific function in eutopic endometrium not replicated in lesions. We suggest that TGFB1-mediated activity is altered in ectopic lesions relative to eutopic endometrium in women with endometriosis, which may affect lesion maintenance. Further research examining the functional consequences of TGFB1 signalling variations is required, including extension of these studies to women without the disorder. Further studies must also carefully consider their housekeeping method and its impact on data and conclusions.