Endometriosis: abnormal endometrium and dysfunctional immune response

A Preliminary Investigation of the Roles of Endometrial Cells in Endometriosis Development via In Vitro and In Vivo Analyses

Endometriosis is a complex gynecological disease that affects more than 10% of women in their reproductive years. While surgery can provide temporary relief from women's pain, symptoms often return in as many as 75% of cases within two years. Previous literature has contributed to theories about the development of endometriosis; however, the exact pathogenesis and etiology remain elusive. We conducted a preliminary investigation into the influence of primary endometrial cells (ECs) on the development and progression of endometriosis. In vitro studies, they were involved in inducing Lipopolysaccharide (LPS) in rat-isolated primary endometrial cells, which resulted in increased nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) mRNA gene expression (quantitative polymerase chain reaction analysis, qPCR) and protein expression (western blot analysis). Additionally, in vivo studies utilized autogenic and allogeneic transplantations (rat to rat) to investigate endometriosis-like lesion cyst size, body weight, protein levels (immunohistochemistry), and mRNA gene expression. These studies demonstrated that estrogen upregulates the gene and protein regulation of cytoskeletal (CK)-18, transforming growth factor-β (TGF-β), VEGF, and tumor necrosis factor (TNF)-α, particularly in the peritoneum. These findings may influence cell proliferation, angiogenesis, fibrosis, and inflammation markers. Consequently, this could exacerbate the occurrence and progression of endometriosis.

Histotyping and grading of endometriosis and its association with clinico-pathological parameters

Current clinical staging/grading schemes of endometriosis show poor correlation with clinical symptoms and histopathological confirmation is only in half of the clinically suspected endometriosis. In this study, done over an 8-year period, several histological features were analysed including an attempt to grade the severity of endometriosis histologically based on the number of foci per low power field. The components in each focus, the phasing of the glands and stroma, the type of glands (endometrial type or undifferentiated type), and stromal features were all analysed. This study attempts to histologically grade endometriosis while relating it to the clinical manifestations and anatomical location. Eighty cases of endometriosis were included. Most common clinical presentation was cyclical pain (n = 62) and the most common anatomical location was adnexa (n = 50). Histologically, severe endometriosis (>3 foci) was seen in 37 cases. The components were mixed in 68 cases. Well-differentiated glandular pattern was typical (n = 54), while 6 cases had undifferentiated. Proliferative phase was seen in 38 cases. Fibrosis and inflammation were present in 29 and 42 cases, respectively. Significant vascular proliferation and plasma cell infiltrate was noted (n = 35). The severe grade was significantly associated with fibrosis (p = 0.03) and inflammation (p = 0.014). Endometriotic foci, unlike eutopic endometrium, shows significant plasma cell infiltrate and vascular proliferation.IMPACT STATEMENTWhat is already known on this subject? Endometriosis, a chronic inflammatory condition in reproductive age group women. The currently used clinical staging and grading systems show poor correlation with patient symptoms and treatment outcomes. Endometriosis with classical histopathological features pose no diagnostic difficulty, however, there is poor concordance with histopathology. Atypical endometriosis is proposed as potential precursor for endometriosis related neoplasms, however, it remains as a controversial entity.What do the results of this study add? The study identifies the uncommon histological patterns which may be encountered in biopsy samples from clinically identified endometriotic lesions. The recognition of these patterns will reduce clinico-pathological discrepancies. In keeping with the other grading systems, attempts at histological grading did not show any correlation with location or patient symptoms. Atypical features were seen only in two cases and was likely to be reactive in nature.What are the implications of these findings for clinical practice and/or further research? Undifferentiated glandular pattern is often a under-recognized histological pattern. Histological grading of severity was a novel attempt to correlate with clinical parameters. Significant plasma cell infiltrate and vascular proliferation in endometriotic foci, underscores the quest for novel therapeutic targets. This study suggests that the use of non-invasive diagnostic methods like fibroscan/inflammatory markers to clinically identify severe disease should be investigated further.

Re-evaluation of mouse models of endometriosis for pathological and immunological research

Endometriosis is an estrogen-dependent gynecological disease with chronic pelvic inflammation. In order to study the pathophysiology of endometriosis and examine the therapeutic effects of new pharmaceuticals for endometriosis treatment, different animal models had been developed in the last two decades, especially mouse models. However, no study evaluated the effects of various modeling approaches on pathology and immunology in endometriosis. This study aimed to compare endometriotic lesion development and immune profiles under different methods of establishing endometriosis models in mice, including estrus synchronization (ovariectomy with estrogen supplement versus male urine-soaked transfer bedding), endometrium preparations (whole uterus including endometrium and myometrium fragments versus solely endometrium fragments), and surgical transplantation (subcutaneous transplantation versus intraperitoneal injection). Our results showed that lesion growth under estrus synchronization by ovariectomy with estrogen supplement had a higher success rate and more proliferative endometrium, apart from higher body weight gain. Immune responses in peripheral blood were similar in the whole uterus and solely endometrium fragments and in intraperitoneal injection and subcutaneous transplantation, but a more innate immune response in the peritoneal microenvironment was found in solely endometrium fragments and intraperitoneal injection than counterparts. In conclusion, different endometriosis modeling methods result in different pathological and immunological features. Ovariectomy with estrogen supplement, solely endometrium fragments, and intraperitoneal injection are more suitable for both pathological and immunological studies of endometriosis in mice, which are important for mechanistic studies and immunotherapy development.

Brief Review of Endometriosis and the Role of Trace Elements

Endometriosis is a chronic, estrogen-dependent, inflammatory condition that is defined as the presence of endometrial glands and stroma outside the uterine cavity. Despite the progress in research into the mechanisms leading to the development of endometriosis, its cause has not yet been established. It seems to be possible that the formation of oxidative stress may be one of the main causes of the development of endometriosis. There is much research that studies the potential role of trace elements in the appearance of endometrial-like lesions. Most studies focus on assessing the content of selected trace elements in the blood, urine, or peritoneal fluid in women with endometriosis. Meanwhile, little is known about the content of these elements in endometrial-like implants, which may be helpful in developing the theory of endometriosis. Investigations that are more comprehensive are needed to confirm a hypothesis that some trace elements play a role in the pathomechanism of endometriosis.

Upregulation of fibroblast growth factor 2 contributes to endometriosis through SPRYs/DUSP6/ERK signaling pathway

Previous studies report that fibroblast growth factor 2 (FGF2) modulates Sproutys (SPRYs)/dual specificity phosphatase 6 (DUSP6)/extracellular signal-regulated kinase (ERK) signaling pathway in endometrial glandular epithelial cells. However, its role in endometriosis remains unclear. The expression patterns and localization of related proteins in endometrium patients' samples were determined using quantitative reverse transcription PCR, Western blotting, and immunohistochemistry, respectively. Human endometrial stromal cells (HESCs) were isolated and transfected with small interfering RNA (siRNA) targeting FGF2 (FGF2-siRNA). Cell viability was determined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. It was found that FGF2 mRNA and protein levels were increased in the ectopic endometrium, whilst the mRNA and protein levels of SPRYs/DUSP6/ERK signaling pathway related-genes were dysregulated. Spearman's rank correlation analysis revealed a negative correlation between FGF2 and SPRYs/DUSP6 signaling pathway-related proteins. In vitro study demonstrated that FGF2 silencing suppressed cell proliferation. Our results suggest that FGF2 upregulation might contribute to endometriosis via the regulation of the SPRYs/DUSP6/ERK signaling pathway.

The Role of Myeloid-Derived Suppressor Cells (MDSCs) in the Development and/or Progression of Endometriosis-State of the Art

Endometriosis (EMS) is a common gynecological disease characterized by the presence of endometrial tissue outside the uterus. Approximately 10% of women around the world suffer from this disease. Recent studies suggest that endometriosis has potential to transform into endometriosis-associated ovarian cancer (EAOC). Endometriosis is connected with chronic inflammation and changes in the phenotype, activity, and function of immune cells. The underlying mechanisms include quantitative and functional disturbances of neutrophils, monocytes/macrophages (MO/MA), natural killer cells (NK), and T cells. A few reports have shown that immunosuppressive cells such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) may promote the progression of endometriosis. MDSCs are a heterogeneous population of immature myeloid cells (dendritic cells, granulocytes, and MO/MA precursors), which play an important role in the development of immunological diseases such as chronic inflammation and cancer. The presence of MDSCs in pathological conditions correlates with immunosuppression, angiogenesis, or release of growth factors and cytokines, which promote progression of these diseases. In this paper, we review the impact of MDSCs on different populations of immune cells, focusing on their immunosuppressive role in the immune system, which may be related with the pathogenesis and/or progression of endometriosis and its transformation into ovarian cancer.

Tumor necrosis factor receptor type 1-associated death domain (TRADD) regulates epithelial-mesenchymal transition (EMT), M1/M2 macrophage polarization and ectopic endometrial cysts formation in endometriosis

Background

Endometriosis is a gynecological non-malignant disease that is manifested by the presence of extrauterine ectopic endometrial cells and stroma. The aim of current study was to explore the role of tumor necrosis factor receptor type 1-associated death domain (TRADD) protein in endometriosis.

Methods

Cell migration, invasion, and the expression of epithelial-mesenchymal transition (EMT) inducers in TRADD silencing or overexpression in eutopic endometrial stromal cells (EuSCs) and ectopic endometrial stromal cells (EcSCs) were analyzed by wound healing assay, transwell assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting and rat endometriosis model. A cell line derived from THP-1 macrophages was used to measure M1/M2 polarization in endometriosis by flow cytometry and enzyme-linked immunosorbent assay (ELISA).

Results

The mRNA level and protein expression of TRADD, keratin, E-cadherin, N-cadherin, vascular endothelial growth factor, matrix metalloproteinase-9, CD40, and CD206 were abnormally expressed in ectopic endometrial tissues and EcSCs. TRADD silencing promoted migration, invasion, and EMT in EuSCs, while TRADD overexpression restrained migration, invasion, and EMT in EcSCs. TRADD knockdown prohibited M1/M2 polarization in normal endometrial homogenization-treated THP-1-derived macrophages, whereas TRADD upregulation facilitated M1/M2 polarization in patients with endometrial homogenization-treated THP-1-derived macrophages. In addition, TRADD overexpression suppressed ectopic endometrial cysts formation in a rat endometriosis model. TRADD overexpression activated NF-κB and MAPK signaling in EcSCs and rat models.

Conclusions

Our results indicated that the overexpression of TRADD prohibited migration, invasion, EMT, M1/M2 polarization and ectopic endometrial cysts formation in endometriosis, and this might due to regulating NF-κB and MAPK signaling.

The role of survivin in the pathogenesis of endometriosis

INTRODUCTION

Endometriosis is a common, estrogen-dependent condition, defined as the presence of endometrial-like tissue outside of the uterus, associated with often chronic and inflammatory reaction. The association of endometriosis with cancer is unclear, although endometriosis and cancer present some molecular similarities. Survinin, encoded by the BIRC5 gene, is a protein that controls cell division, inhibits apoptosis and promotes angiogenesis. Here we aimed to summarize and to discuss the main findings of studies that addressed the involvement of survivin in the pathogenesis of endometriosis.

EVIDENCE ACQUISITION

We conducted a comprehensive retrieval from electronic databases, included the MEDLINE, EMBASE, with no restrictions to time span. We used the search terms endometriosis and survivin or BIRC5 and collected all relevant studies to explore the association between endometriosis and surviving expression.

EVIDENCE SYNTHESIS

A total of 21 studies included in the systematic review, comprising sample collected from 1263 women with endometriosis. Results showed the involvement of more than 60 genes and proteins evaluated in eutopic, ectopic, endometrial and ovarian endometriosis, as well as in several gynecological conditions compared to healthy controls.

CONCLUSIONS

The studies provided the basis for the involvement of survivin in the pathogenesis of the disease by several and independent pathways.

Endometriotic lesions

Endometriosis is a complex gynaecological condition affecting women of reproductive age. It is characterised by the presence of lesions containing endometrial glands and stroma outside the uterus. The disease is typically associated with pelvic pain (including dysmenorrhoea and dyspareunia), infertility and bowel-related symptoms. Endometriotic lesions have a highly variable presentation and most commonly occur in the abdominal cavity. These lesions are broadly classified into peritoneal, ovarian and deep infiltrating endometriosis. There have been observations of increased density of nerve fibres and neurological molecules in the endometriotic lesions compared to the uninvolved peritoneum of women without endometriosis and the presence of unmyelinated nerve fibres were higher near the glands. The lesion sites are characterised by a range of immunological alterations, and specific immune cell populations have also been known to synthesise and secrete neurogenic factors. Endometriotic lesions are capable of producing prostaglandins which are direct generators of pain and are capable of inducing inflammation. Diagnosing the disease involves direct visualisation of the lesions through a laparoscopic or laparotomy, which is followed by histopathological examination of biopsied or excised lesions. The staging of endometriosis due to its complexity is highly variable as presentation and gaps in knowledge pose a great challenge in the classification of the disease. The medical management of endometriosis aims at providing adequate analgesia and suppression of the activity of the lesion. A better understanding of endometriotic lesion relationships between innervations and specific clinical characteristics may elucidate aspects of pain mechanisms and infertility in endometriosis and facilitate the development of novel therapeutic approaches.

Recent Advances in Molecular Genetics of Endometriosis

Endometriosis (MIM 131200) is a prevalent and complex gynecological disease polygenically inherited with multifactorial pathogenesis. It is increasingly recognized as a major women's health issue. Endometriosis is characterized by the presence of endometrial-like tissue in sites outside the uterus, mainly the pelvic peritoneum, ovaries and rectovaginal septum causing severe dysmenorrhoea, dyspareunia, chronic pelvic pain and subfertility. Recent advances in molecular technologies have provided many evidences about the underlying biological events that are likely to be involved in the development of endometriosis. Different chromosomal regions, genes and other molecules, such as microRNAs, have been identified as potentially involved in endometriosis pathogenesis. Moreover, genome-wide analyses of endometriosis have showed novel molecular signatures or individual genes that had not been previously associated with the disease. The goal of these studies is to provide information that might, in turn, lead to new therapies. In this review, some previous studies were updated supporting the polygenic/multifactorial inheritance and the association with malignant neoplasias. We have also emphasized the importance of identifying the causative genes and determining novel diagnostic and predictive biomarkers.

Endometriosis: Aetiopathogenetic Basis

Endometriosis, defined by the presence of endometrial tissue outside the uterine cavity, is a common condition affecting 10% of women in the reproductive age. Menstrual factors reported to increase risk include dysmenorrhea, early menarche, and shorter cycle lengths. The theory of retrograde menstruation with implantation of endometrial fragments, in conjunction with peritoneal factors to stimulate cell growth is the most widely accepted.

There is a growing body of evidence that immunological factors and angiogenesis play a key role in the pathogenesis of endometriosis. In women with endometriosis, there appears to be an alteration in the function of peritoneal macrophages, natural killer cells and lymphocytes, with production of growth factors and inflammatory mediators in the peritoneal fluid. Survival, adhesion, proliferation, invasion and vascularization of endometrial tissue in abdominal cavity may be the consequence of retrograde menstruation and referred to as implantation theory.

Protein-protein interaction analysis to identify biomarker networks for endometriosis

The identification of biomarkers and their interaction network involved in the processes of endometriosis is a critical step in understanding the underlying mechanisms of the disease. The aim of the present study was to construct biomarker networks of endometriosis that integrated human protein-protein interactions and known disease-causing genes. Endometriosis-associated genes were extracted from Genotator and DisGeNet and biomarker network and pathway analyses were constructed using atBioNet. Of 100 input genes, 96 were strongly mapped to six major modules. The majority of the pathways in the first module were associated with the proliferation of cancer cells, the enriched pathways in module B were associated with the immune system and infectious diseases, module C included pathways related to immune and metastasis, the enriched pathways in module D were associated with inflammatory processes, and the majority of the pathways in module E were related to replication and repair. The present approach identified known and potential biomarkers in endometriosis. The identified biomarker networks are highly enriched in biological pathways associated with endometriosis, which may provide further insight into the molecular mechanisms underlying endometriosis.

Cervical mucus proteome in endometriosis

Background

Endometriosis is a chronic gynecological inflammatory disease characterized by the presence of functional endometrial glands and stroma outside of the uterine cavity. It affects 7–10% of women of reproductive age and up to 50% of women with infertility. The current gold standard for the diagnosis combines laparoscopic evaluation and biopsy of the visualized lesions. However, laparoscopy requires general anesthesia and developed surgical skills and it has a high procedural cost. In addition, it is associated with the risk, although rare, of potential intraoperative or postoperative complications. To date, several noninvasive biomarkers have been proposed; however, no definite diagnostic biomarker is yet available. The aim of this study was to characterize the CM proteome in patients with endometriosis using high resolution mass spectrometry—based proteomics, implemented by bioinformatic tools for quantitative analysis, in order to investigate the pathophysiological mechanisms of endometriosis.

Methods

Cervical mucus samples were collected from patients affected by endometriosis and fertile controls. An aliquot of the soluble acidic fraction of each cervical mucus sample, corresponding to 0.5 mg of total protein, was left to digest with sequencing grade modified porcine trypsin. The peptides were analyzed by LC–MS/MS on a high resolution Orbitrap Elite mass spectrometer and data were evaluated using bioinformatic tools.

Results

We aimed at the first total profiling of the cervical mucus proteome in endometriosis. From the list of identified proteins, we detected a number of differentially expressed proteins, including some functionally significant proteins. Six proteins were quantitatively increased in endometriosis, almost all being involved in the inflammatory pattern. Nine proteins were quantitatively reduced in endometriosis, including some proteins related with local innate immunity (CRISP-3 and Pglyrp1) and protection against oxidative stress (HSPB1). Fifteen proteins were not detected in endometriosis samples including certain proteins involved in antimicrobial activity (SLURP1 and KLK13) and related to seminal plasma liquefaction and male fertility (KLK13).

Conclusions

This is the first application of high resolution mass spectrometry—based proteomics aimed in detecting an array of proteins in CM to be proposed for the noninvasive diagnosis of endometriosis. This chronic disease presents in CM an inflammatory protein pattern.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-017-9142-4) contains supplementary material, which is available to authorized users.

Polymorphisms of ICAM-1 and IL-6 genes related to endometriosis in a sample of Brazilian women

PURPOSE

This study investigated the possibility of K469E (rs5498) and G241R (rs1799969) polymorphisms, in ICAM-1 gene, and G634C (rs1800796), in IL-6 gene, being associated with the occurrence of endometriosis in a sample of Brazilian women.

METHODS

We genotyped 200 women (100 in control group and 100 in endometriosis group) by PCR-RFLP technique for G634C, K469E, and G241R polymorphisms.

RESULTS

No significant difference was observed in genotypic frequency between control and endometriosis groups for G634C and K469E polymorphisms (p = 0.61 and p = 0.22, respectively). In addition, no significant difference between stages I-II and III-IV of the disease was found for both SNPs (p = 0.63 and p = 0.24, respectively). All individuals were wild homozygotes for G241R polymorphism.

CONCLUSION

This study suggests that polymorphisms K469E, G241R, and G634C are not associated with increased susceptibility to endometriosis in Brazilian women.

Increased percentage of Th17 cells in peritoneal fluid is associated with severity of endometriosis

AIM

Th17 cells are a newly discovered T helper lymphocyte subpopulation, producing interleukin IL-17. Th17 cells are present in blood and peritoneal fluid (PF) at different stages of endometriosis. We aim to establish their potential importance in the pathogenesis and clinical features of the disease.

METHODS

The percentage of Th17 cells among T helper lymphocytes was determined in the PF and peripheral blood (PB) of patients with endometriosis and in the control group by flow cytometry using monoclonal antibodies: anti-CD-4-FITC, anti-CD-3-PE/Cy5, and anti-IL-17A-PE.

RESULTS

Th17 percentage is increased in PF in comparison with PB in both endometriotic patients and in the control group. In severe endometriosis, the percentage of Th17 cells in PF was higher than with early (I/II stage) endometriosis. A positive correlation between the percentage of Th17 cells in PF and the white blood cell count in PB was found in patients with endometriosis.

CONCLUSION

Targeting the activity of PF Th17 cells may have an influence on the proliferation of ectopic tissue and clinical manifestations of the disease.

Galectin-1 overexpression in endometriosis and its regulation by neuropeptides (CRH, UCN) indicating its important role in reproduction and inflammation

Endometriosis is an inflammatory disease of women of reproductive age featured by the presence of ectopic endometrium and is strongly related to infertility. Galectins, carbonhydrate-binding proteins, have been found to have pro- or anti-inflammatory roles in the reproductive tract and in pathological conditions concerning infertility. Galectin-1, which is expressed at endometrium and decidua, plays a major role in implantation and trophoblast invasion. Also, the neuropeptides, corticotropin releasing hormone (CRH) and urocortin (UCN) and their receptors are expressed in eutopic and ectopic endometrium showing a differential expression pattern in endometriotic women compared to healthy ones. The aim of this study was to examine the galectin-1 expression in endometriotic lesions and compare its expression in eutopic endometrium of endometriotic and healthy women. Furthermore, we examined the effect of CRH and UCN in galectin-1 expression in Ishikawa cell line and macrophages and investigated the implication of CRHR1 in these responses. Eutopic and ectopic endometrium specimens, Ishikawa cell line and mice macrophages were used. Immunohistochemistry and western blot analysis were performed in order to identify galectin-1 expression in ectopic and eutopic endometrium of women with and without endometriosis and the regulatory effect of CRH and UCN on galectin-1 expression. This study presents for the first time that galectin-1 is overexpressed in endometriotic lesions compared to eutopic endometrium of endometriotic women and is more abundantly expressed in eutopic endometrium of disease women compared to healthy ones. Furthermore, it is shown that CRH and UCN upregulate galectin-1 expression in Ishikawa cell line and macrophages and this effect is mediated through CRHR1. These results suggest that galectin-1 might play an important role in endometriosis pathology and infertility profile of women suffering from endometriosis by being at the same time regulated by CRH and UCN interfering in the immune disequilibrium which characterizes this pathological condition.

T regulatory lymphocytes in patients with endometriosis

The present study aimed to investigate the presence of T regulatory cells (Tregs) in the peripheral blood (PB) and peritoneal fluid (PF) in females with endometriosis. The present study included 42 patients who underwent laparoscopy between 2010 and 2011. Flow cytometry was used to determine the percentage of Tregs in the PF and PB of the patients. No significant difference was observed in the percentage of Tregs in the patients in the endometriosis group compared with those in the control group in the PF (9.1±5.4 vs. 9.1±3.8%) or the PB (6.5±3.2 vs. 6.5±3.7%). However, the percentage of Tregs was found to be higher in the PF compared with the PB in the patients in the endometriosis and control groups, but significance was found only in those in the control group. Furthermore, no significant difference was observed in the Treg concentration in the patients with early stage (I/II) endometriosis compared with those with late stage (III/IV) endometriosis. Moreover, no significant correlation was found between the percentage of Tregs and the white blood cell count, lymphocyte count or CA125 concentration in the patients. These findings suggest that the local host‑defense mechanism is deficient in patients with endometriosis, thus endometriosis should not be treated as an autoimmune condition.

The association between endometriosis and chronic endometritis

Objective

To evaluate the association between endometriosis and chronic endometritis.

Methods

Endometrial specimens were obtained from 71 patients, 34 with endometriosis (endometriosis group) and 37 without endometriosis (non-endometriosis group), who underwent hysterectomy, and the specimens were immunostained for the plasmacyte marker CD138. The rate of chronic endometritis was compared between the endometriosis group and the non-endometriosis group. Furthermore, the 71 patients were also divided into two groups, 28 with chronic endometritis (chronic endometritis group) and 43 without chronic endometritis (non-chronic endometritis group). Logistic regression analysis was performed with variables including age, body mass index (BMI), gravidity and parity, and diagnoses of leiomyoma, adenomyosis, and endometriosis on pathology to examine the independent effect of each variable on chronic endometritis. Patients suffering from cervical invasive carcinoma, endometrial carcinoma, and endometrial polyps or treated with gonadotropin-releasing hormone agonists, progestins, or oral contraceptives before surgery were excluded.

Results

Chronic endometritis was identified in 52.94% of the endometriosis group and 27.02% of the non-endometriosis group (p<0.05). Logistic regression analysis revealed that endometriosis was associated with chronic endometritis.

Conclusions

This result suggests a strong association between endometriosis and chronic endometritis.

Immunology of normal and abnormal menstruation

Normal menstruation is an inflammatory process, where the endometrial concentrations and functions of several leukocyte types can change greatly through the menstrual cycle, especially during the premenstrual and menstrual phases. These leukocytes probably have a range of functions related to mucosal protection, decidualization, embryo implantation, and the process of menstrual tissue breakdown, repair and remodeling. Some of these leukocyte changes are apparently linked to changes in the pattern of circulating leukocytes. Many immune cells have been identified in the endometrium, and those with most relevance to the processes of menstruation include uterine natural killer cells, macrophages, mast cells, neutrophils, dendritic cells and Tregs. A range of disturbances in endometrial immune cell numbers, distributions and functions, and in a range of different inflammatory and other mediators, have been identified in women with heavy menstrual bleeding or endometriosis. Sufficient evidence exists to implicate these immune changes in some of the functional disturbances and symptoms identified in these women. This field is greatly under-researched, and ripe for the wider application of modern molecular and cellular techniques in human and animal model studies.

Anti-TNF-α treatment for pelvic pain associated with endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that can develop during the reproductive years. It is characterised by the development of endometrial tissue outside the uterine cavity. It is the most common cause of pelvic pain in women. This endometrial tissue development is dependent on oestrogen produced primarily by the ovaries and, therefore, traditional management has focused on suppression of ovarian function. Mounting evidence shows that altered immune function plays a crucial role in the genesis and development of endometriosis. In this review we considered modulation of the inflammation as an alternative approach.

OBJECTIVES

To determine the effectiveness and safety of anti-tumour necrosis factor-α (anti-TNF-α) treatment in the management of endometriosis in premenopausal women.

SEARCH METHODS

For the first publication of this review, we searched for trials in the following databases (from their inception to August 2009): Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, we searched all reference lists of included trials and contacted experts in the field in an attempt to locate trials. We reran this search to 3 September 2012 for this update.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing anti-TNF-α drugs with placebo, no treatment, medical treatment, or surgery for pelvic pain associated with endometriosis were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted data using data extraction forms. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. We used risk ratios (RR) for reporting dichotomous data with 95% confidence intervals (CI), whilst we expressed continuous data as mean differences (MD). We assessed statistical heterogeneity using the I(2) statistic.

MAIN RESULTS

Only one trial involving 21 participants was included. The results showed no evidence of an effect of infliximab, one of the known anti-TNF-α drugs, on pelvic pain reduction using the Biberoglu-Behrman (BB) score (0 to 3 scale) for participants (MD -0.14, 95% CI -0.43 to 0.15), the BB score for clinicians (MD -0.14, 95% CI -0.39 to 0.11), or a visual analogue pain score (VAS, 100 mm scale) (MD -5.60, 95% CI -16.10 to 4.90), or on the use of pain killers (ibuprofen, g/day) (MD -0.10, 95% CI -0.30 to 0.10). There was no evidence of an increase in adverse events in the infliximab group compared with placebo (RR 3.73, 95% CI 0.22 to 63.66). We found no evidence of clinical benefits of infliximab for endometriotic lesions, dysmenorrhoea, dyspareunia, or pelvic tenderness. To date, there is no trial that has reported a cost-effectiveness analysis of anti-TNF-α drugs, or the odds of recurrence.

AUTHORS' CONCLUSIONS

This review was updated in 2012. The results of the original review published in 2010 remain unchanged. There is still not enough evidence to support the use of anti-TNF-α drugs in the management of women with endometriosis for the relief of pelvic pain.

Expression of human β-defensin-2 in the eutopic and ectopic endometrial tissues in patients with endometriosis

OBJECTIVE

To investigate the expression of human β-defensin-2 (hBD-2) in the endometrium of patients with endometriosis (EMS) and explore the potential role of hBD-2 in the pathogenesis of EMS.

DESIGN

Prospective controlled study.

SAMPLE

50 women including EMS patients undergoing laparoscopic ovarian cystectomy and non-EMS patients undergoing hysterectomy for uterine fibroids.

SETTING

Large university teaching hospital.

METHODS

Patients were divided into EMS and non-EMS groups. The gene expressions of hBD-2, interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the endometrial tissues of each group were detected with real-time quantitative polymerase chain reaction (PCR), and hBD-2 protein expression with immunohistochemical method.

RESULTS

The gene expression levels of hBD-2, TNF-α, and IL-1β as well as the positive expression rate of hBD-2 protein in the ectopic endometrium of EMS patients were significantly higher than those in the eutopic endometrium of EMS and non-EMS patients (all P < 0.05). Correlation analysis showed that the gene expression levels of hBD-2 in the ectopic and eutopic endometrium of EMS patients were positively correlated with the gene expression levels of IL-1β and TNF-α (P < 0.01).

CONCLUSION

High levels of hBD-2 gene and protein expressions in the ectopic endometrium of EMS patients may be an important contributor in the pathogenesis of EMS. TNF-α and IL-1β may promote the upregulation of hBD-2 expression.

TYK2 rs34536443 polymorphism is associated with a decreased susceptibility to endometriosis-related infertility

INTRODUCTION

Tyrosine kinase 2 gene (TYK2) is part of the janus kinase (JAK) that binds to the type I interferon-α receptor (IFNAR) on the cell surface of IFN-producing cells, and have crucial importance in the etiology of autoimmune and inflammatory diseases. Many polymorphisms of the TYK2 gene have been identified, and recently, a number of case-control studies were conducted to investigate the association of these polymorphisms with autoimmune and inflammatory diseases, with conflicting results. Based on these observations, we hypothesized that the TYK2 polymorphisms (rs34536443, rs2304256, rs280523, rs12720270 and rs12720356) might be involved in the pathogenesis of endometriosis and/or infertility.

METHODS

Genetic association study comprising 275 infertile women with endometriosis, 92 women with idiopathic infertility and 307 fertile women as controls. TYK2 polymorphisms were identified by TaqMan PCR. Genotype distribution, allele frequency and haplotype analysis of the TYK2 polymorphisms were performed. A p-value <0.05 was considered significant.

RESULTS

Single-marker analysis revealed that TYK2 rs34536443 was significantly associated with protection against endometriosis-related infertility, especially in moderate/severe disease (p = 0.002; OR = 0.24, 95% IC = 0.09-0.62). No difference was found considering the infertile group without endometriosis. No associations were found considering rs2304256, rs280523, rs12720270 and rs12720356 either for endometriosis-related infertility group or idiopathic infertility group. Haplotype analysis of five TYK2 polymorphisms identified a haplotype "CTATG" associated with protection against endometriosis-related infertility, especially in moderate/severe disease (p = 0.027).

CONCLUSION

This is the first study to report an association between TYK2 polymorphisms and endometriosis and/or infertility. These findings require replication in other populations but suggest the TYK2 rs34536443 polymorphisms and "CTATG" haplotype can be associated with a decreased susceptibility to endometriosis-related infertility in Brazilian women.

Pentoxifylline for endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that occurs during the reproductive years. It is characterized by endometrial tissue developing outside the uterine cavity. This endometrial tissue development is dependent on oestrogen produced primarily by the ovaries and, therefore, traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach. This is an update of a Cochrane Review previously published in 2009 (Lu 2009).

OBJECTIVES

To assess the effects of pentoxifylline, which has anti-inflammatory effects, in subfertile, premenopausal women for the management of endometriosis.

SEARCH METHODS

For the first publication of this review we searched the following databases (from inception to December 2008) for trials: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials. This search was rerun to 23 November 2011, for this update.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, medical treatment, or surgery in subfertile, premenopausal women were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial risk of bias, and extracted data using data extraction forms. We contacted study authors for additional information and data. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Peto odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I(2) statistic.

MAIN RESULTS

Four trials involving 334 participants were included. One RCT [n=34] showed pentoxifylline had no significant effect on reduction in pain (MD -1.60, 95% CI -3.32 to 0.12). There was no evidence of an increase in clinical pregnancy events in the pentoxifylline group compared with placebo (three RCTs [n=67] OR 1.54, 95% CI 0.89 to 266). One RCT studied recurrence of endometriosis [n=88] (OR 0.88,95% CI 0.27 to 2.84). No trials reported the effects of pentoxifylline on the odds of live birth rate per woman, improvement of endometriosis-related symptoms, or adverse events.

AUTHORS' CONCLUSIONS

This review has been updated in 2011. The results of the original review published in 2009 remain unchanged. There is still not enough evidence to support the use of pentoxifylline in the management of premenopausal women with endometriosis in terms of subfertility and relief of pain outcomes.

Imbalance between sympathetic and sensory innervation in peritoneal endometriosis

To investigate possible mechanisms of pain pathophysiology in patients with peritoneal endometriosis, a clinical study on sensory and sympathetic nerve fibre sprouting in endometriosis was performed. Peritoneal lesions (n=40) and healthy peritoneum (n=12) were immunostained and analysed with anti-protein gene product 9.5 (PGP 9.5), anti-substance P (SP) and anti-tyrosine hydroxylase (TH), specific markers for intact nerve fibres, sensory nerve fibres and sympathetic nerve fibres, respectively, to identify the ratio of sympathetic and sensory nerve fibres. In addition, immune cell infiltrates in peritoneal endometriotic lesions were analysed and the nerve growth factor (NGF) and interleukin (IL)-1β expression was correlate with the nerve fibre density. Peritoneal fluids from patients with endometriosis (n=40) and without endometriosis (n=20) were used for the in vitro neuronal growth assay. Cultured chicken dorsal root ganglia (DRG) and sympathetic ganglia were stained with anti-growth associated protein 43 (anti-GAP 43), anti-SP and anti-TH. We could detect an increased sensory and decreased sympathetic nerve fibres density in peritoneal lesions compared to healthy peritoneum. Peritoneal fluids of patients with endometriosis compared to patients without endometriosis induced an increased sprouting of sensory neurites from DRG and decreased neurite outgrowth from sympathetic ganglia. In conclusion, this study demonstrates an imbalance between sympathetic and sensory nerve fibres in peritoneal endometriosis, as well as an altered modulation of peritoneal fluids from patients with endometriosis on sympathetic and sensory innervation which might directly be involved in the maintenance of inflammation and pain.

Endometriosis for the colorectal surgeon

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity. Although the exact pathophysiology is unclear, endometriosis is a well-known cause of pelvic pain and infertility in reproductive-aged women. Endometriosis can have extrapelvic manifestations relevant for colorectal surgeons to appreciate, such as cyclic constipation, diarrhea, hematochezia, and dyschezia. The treatment of endometriosis involves a combination of medical and surgical interventions where close collaboration between the gynecologist and colorectal surgeon can help achieve prolonged periods of symptom remission.

Deregulation of LOXL1 and HTRA1 gene expression in endometriosis

Endometriosis is a gynecologic disease characterized by the presence of endometrial tissue outside the uterine cavity. Although 15% of the female population in reproductive age is affected by endometriosis, its pathogenesis remains unclear. According to the most accepted pathogenesis hypothesis, endometrial fragments from the menstrual phase are transported through the uterine tubes to the peritoneal cavity, where they undergo implantation and growth, invading adjacent tissues. However, the establishment of the disease requires that endometrial cells present molecular characteristics favoring the onset and progression of ectopic implantation. In this investigation, we analyzed the differential gene expression profiles of peritoneal and ovarian endometriotic lesions compared to the endometrial tissue of nonaffected women using rapid subtraction hybridization (RaSH). In our study, this method was applied to samples of endometriotic lesions from affected women and to biopsies of endometrium of healthy women without endometriosis, where we could identify 126 deregulated genes. To evaluate the expression of genes found by RaSH method, we measured LOXL1, HTRA1, and SPARC genes by real-time polymerase chain reaction. Significant different expression was obtained for HTRA1 and LOXL1, upregulated in the ectopic endometrium, suggesting that these genes are involved in the physiopathology of endometriosis and may favor the viability of endometrial cells at ectopic sites.

Anti-TNF-alpha treatment for pelvic pain associated with endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that can develop during the reproductive years. It is characterized by the development of endometrial tissue outside the uterine cavity. It is the most common cause of pelvic pain in women. This endometrial tissue development is dependent on estrogen produced primarily by the ovaries and, therefore, traditional management has focused on suppression of ovarian function. The mounting evidence shows that altered immune function plays a crucial role in the genesis and development of endometriosis. In this review we considered modulating the inflammation as an alternative approach.

OBJECTIVES

To determine the effectiveness and safety of anti-tumour necrosis factor-alpha (anti-TNF-alpha) drugs in the management of pelvic pain associated with endometriosis.

SEARCH STRATEGY

We searched for trials in the following databases (from their inception to August 2009): Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing anti-TNF-alpha drugs with placebo, no treatment, medical treatment, or surgery for pelvic pain associated with endometriosis were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted data using data extraction forms. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Risk ratios (RR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I(2) statistic.

MAIN RESULTS

Only one trial involving 21 participants was included. Results showed no evidence of an effect of infliximab, one of the known anti-TNF-alpha drugs, on pain reduction using the Biberoglu-Behrman (BB) score for patients (MD -0.15, 95% CI -0.51 to 0.21), the BB score for clinicians (MD -0.15, 95% CI -0.45 to 0.15), the visual analogue pain score (VAS) (MD 11.30, 95% CI -3.00 to 25.60) and the use of pain killers (MD -0.10, 95% CI -0.60 to 0.40). There was no evidence of an increase in adverse events in the infliximab group compared with placebo (RR 3.73, 95% CI 0.22 to 63.66). No evidence of clinical benefits of infliximab was found for endometriotic lesions, dysmenorrhoea, dyspareunia or pelvic tenderness. No trial reported the effects of anti-TNF-alpha drugs using economic evaluations and the odds of recurrence.

AUTHORS' CONCLUSIONS

There is no enough evidence to support the use of anti-TNF-alpha drugs in the management of women with endometriosis for the relief of pelvic pain.

Pentoxifylline versus medical therapies for subfertile women with endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that occurs during the reproductive years. It is characterized by endometrial tissue developing outside the uterine cavity. This endometrial tissue development is dependent on estrogen produced primarily by the ovaries and, therefore, traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach.

OBJECTIVES

To determine the effectiveness and safety of pentoxifylline, which has anti-inflammatory effects, in the management of endometriosis in subfertile, premenopausal women.

SEARCH STRATEGY

We searched the following databases (from inception to December 2008) for trials: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, medical treatment, or surgery in subfertile, premenopausal women were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted data using data extraction forms. We contacted study authors for additional information and data. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I(2) statistic.

MAIN RESULTS

Four trials involving 334 participants were included. Results showed pentoxifylline had no significant effect on reduction in pain (one RCT, MD -1.60, 95% CI -3.32 to 0.12). There was no evidence of an increase in clinical pregnancy events in the pentoxifylline group compared with placebo (three RCTs, OR 1.54, 95% CI 0.89 to 266). For recurrence of endometriosis, one RCT reported an OR of 0.88 (95% CI 0.27 to 2.84). No trials reported the effects of pentoxifylline on the odds of live birth rate per woman, improvement of endometriosis-related symptoms, or adverse events.

AUTHORS' CONCLUSIONS

There is not enough evidence to support the use of pentoxifylline in the management of premenopausal women with endometriosis in terms of subfertility and relief of pain outcomes.

Adenomyosis: New Knowledge is Generating New Treatment Strategies

In the early days, all mucosal invasions of abdominal organs were considered to be one pathological condition of uncertain origin, termed adenomyoma. It was only in the 1920s that endometriosis and adenomyosis were clearly separated and it took approximately 80 years to put forward a new theory reunifying their pathogenesis. Today, identification of adenomyosis is carried out exclusively through vaginal ultrasonography and MRI. These techniques have made a careful evaluation of a distinct anatomical structure and the inner myometrial layers underlying the endometrium, termed the junctional zone, possible. Adenomyosis is characterized by a homogeneous thickening of this portion of the myometrium. When this hyperplasia is associated to an alteration of spiral arterioles' angiogenesis, then both adenomyosis and endometriosis may develop. Evidence is being accumulated that pre-eclampsia, fetal growth restriction and premature delivery may be linked, together representing a new, major obstetrical syndrome characterized by a modified uterine environment around the time of nidation. A dozen different medical or surgical techniques are utilized for the treatment of adenomyosis and novel approaches are being tested. These include use of inhibitors of angiogenesis that have been shown to cause reduced neo-angiogenesis, a significant modification of gene expression and a decrease in the percentage of active lesions. Encouraging results have also been obtained with the levonorgestrel-releasing intrauterine system.

Reduced fecundity in female rats with surgically induced endometriosis and in their daughters: a potential role for tissue inhibitors of metalloproteinase 1

The cause of reduced fecundity in women with endometriosis is unknown. Expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by both ectopic and eutopic endometrium reportedly has a role in the pathogenesis of endometriosis. We hypothesize that anomalous endometriotic TIMP protein synthesis, secretion, and localization also cause reproductive pathologies resulting in reduced fecundity. An established rat model for endometriosis (Endo) compared with nonendometriotic controls (Shams) was used to investigate reduced fecundity in endometriosis. Comparing Endo and Sham rats, Endo rats had altered ovarian dynamics, including fewer ovarian follicles and corpora lutea with luteinized unruptured follicles. Furthermore, in vivo anomalies in postovulatory oocyte structure and preimplantation embryo development, including misaligned chromosomes, nuclear and cytoplasmic fragmentation, and delayed or arrested cleavage, as well as spontaneous abortions, were found only in Endo rats. A causative role for TIMP1 in these phenomena is supported by our findings that Endo rats have more TIMP1 in their peritoneal fluid as detected by ELISA and more TIMP1 immunolocalization in the theca of antral follicles as measured by computer-assisted morphometric analysis. These data suggest that in endometriosis the accumulation of TIMP1 disrupts the normal MMP/TIMP enzymatic milieu in the peritoneal cavity and negatively affects ovarian dynamics, oocyte quality, and preimplantation embryo development, thereby decreasing fecundity. Most intriguingly, daughters of Endo rats that had no experimental interventions exhibited these same reproductive abnormalities. We predict that developmental exposure to endometriosis leads to permanent epigenetic changes in subsequent generations.

Endometriosis and Chronic Pelvic Pain: Unraveling the Mystery Behind this Complex Condition

Nurses often encounter patients with chronic pelvic pain associated with endometriosis, which is a puzzling and problematic gynecologic condition that has continued to plague women and baffle doctors and researchers worldwide since it was first identified by Dr. J. Sampson in the 1920s (Sampson, 1940 ). Endometriosis is defined as the growth, adhesion and progression of endometrial glands and stroma outside of the uterine cavity, with cellular activity evident in lesions, nodules, cysts or endometriomas (Audebert et al., 1992 ). Although it typically appears benign on histopathology, endometriosis has been likened to a malignant tumor since the lesions grow, infiltrate and adhere to adjacent tissues and interfere with physiologic processes (Kitawaki et al., 2002 ; Noble, Simpson, Johns, & Bulun, 1996 ). Ectopic endometriotic growths respond to cyclic changes of estrogen and proliferate and shed in a manner similar to eutopic endometrium. This cyclic ectopic activity results in internal bleeding, formation of scar tissue, inflammation and sometimes debilitating chronic pain (Kitawaki et al.).

Dioxin may promote inflammation-related development of endometriosis

Laboratory and population-based studies suggest that exposure to environmental toxicants may be one of several triggers for the development of endometriosis. We discuss evidence that modulation of the endometrial endocrine-immune interface could mechanistically link toxicant exposure to the development of this disease.

Role of shigella infection in endometriosis: A novel hypothesis

Endometriosis is the presence of endometrial cells and stroma at ectopic sites outside the uterine cavity. The natural history of endometriosis is uncertain, its etiology unknown, the clinical presentation inconsistent, diagnosis difficult and the treatment poorly standardized. It causes significant morbidity due to pelvic pain and infertility among 15-25% of women during their reproductive age. The benign disease causes peritoneal inflammation, fibrosis, adhesions and ovarian cysts but displays features of malignancy, like neo-vascularization, local invasion and distant metastasis. Mechanical, hormonal, immunological, environmental and genetic factors have been implicated in its etiology but provide inconclusive explanations. Present study was carried out on ectopic and eutopic endometriotic tissue specimens collected during laproscopy/laprotomy from cases of endometriosis. mRNA was isolated from the tissues and converted to cDNA by RT and subsequently subjected to differential display Polymerase Chain Reaction using seven sets of arbitrary primers. A unique band was identified only in the ectopic endometriotic tissue, which was sequenced. BLAST search results revealed sequence homology to shigella bacterial DNA leading us to hypothesize that infection may be playing a role in the etiology of endometriosis. This is the first report implicating the role of bacterial infection in the etiology of endometriosis. Shigella is known to invade the mucosa of the colon through the feco-oral route causing Shigellosis. The pathogenesis of shigellosis involves inflammation, ulceration, haemorrhage, tissue destruction and fibrosis of the colonic mucosa resulting in abdominal pain and diarrhoea/dysentery, this is similar to the pathogenesis of endometriosis which also involves inflammation, haemorrhage, tissue destruction and fibrotic adhesions of the pelvic peritoneum resulting in abdominal pain and infertility. The non-motile shigella bacteria invade the deeper mucosal layers by travelling from cell to cell of colonic epithelium, reaching the lamina propria of the colonic mucosa. We propose that, by the same mechanism, the bacteria travel across the colon wall to reach the outer peritoneal surface of the colon, which is in close proximity to the posterior uterine surface in the Pouch of Douglas, the site which incidentally happens to be the commonest site of early endometriosis. Our hypothesis therefore proposes that shigella or shigella-like organisms may be the trigger for the initiation of immunological changes in the pelvic peritoneum causing endometriosis. Once the endometrial cells are implanted at ectopic sites they are sustained by hormones and angiogenic factors. Hence "Infection hypothesis" provides a novel explanation for the etiopathogenesis of endometriosis.

Paracrine regulation of endometriotic tissue

Endometriosis is a chronic estrogen-dependent gynecological disease, characterized by pelvic pain and infertility, defined as the presence of endometrial glands and stroma within the pelvic peritoneum and other extrauterine sites. In the peritoneal cavity endometrial cells adhere, proliferate and induce an inflammatory response. Despite a long history of clinical and experimental research, the pathogenesis of endometriosis is still controversial. Abnormal immunological activation, the endocrine milieu and the peritoneal environment all dramatically affect endometriotic tissue function. Recent studies suggest that the peritoneal fluid of women with endometriosis contains an increased number of activated macrophages and other immune cells that secrete various local products, such as growth factors and cytokines, which exert a paracrine action on endometriotic cells. Since the peculiar biological characteristics of eutopic endometrium from women with endometriosis differ from endometrium of normal subjects, an important role in the pathogenesis of this complex disease has been suggested. All of these factors contribute to enhanced proliferative and angiogenic activity and a number of functional and structural changes, resulting in the particular behavior of this tissue.

Targeting mast cells in endometriosis with janus kinase 3 inhibitor, JANEX-1

Endometriosis (EMS) is a chronic inflammatory disease of multifactorial etiology characterized by implantation and growth of endometrial glands and stroma outside the uterine cavity. EMS is a significant public health issue as it affects 15-20% of women in their reproductive age. Clinical symptoms may include pelvic pain, dysmenorrhea, dyspareunia, pelvic/abdominal masses, and infertility. Symptomatic treatments such as surgical resection and/or hormonal suppression of ovarian function and analgesics are not as effective as desired. Consequently, there is an enormous unmet need to develop effective medical therapy capable of preventing the occurrence and recurrence of EMS without undesirable side-effects. EMS-associated intra-abdominal bleeding episodes, local inflammation, adhesions, and i.p. immunologic dysfunction leads to pelvic nociception and pelvic pain. Increasing evidence supports the involvement of allergic-type inflammation in EMS. Invasion of mast cells, degranulation, and proliferation of interstitial component are observed in endometriotic lesions. Presence of activated and degranulating mast cells within the nerve structures can contribute to the development of pain and hyperalgesia by direct effects on primary nociceptive neurons. Therefore, treatments targeting endometrial mast cells may prove effective in preventing or alleviating EMS-associated symptoms. The Janus kinase 3 (JAK3) is abundantly expressed in mast cells and is required for the full expression of high-affinity IgE receptor-mediated mast cell inflammatory sequelae. JANEX-1/WHI-P131 is a rationally designed novel JAK3 inhibitor with potent anti-inflammatory activity in several cellular and in vivo animal models of inflammation, including mouse models of peritonitis, colitis, cellulitis, sunburn, and airway inflammation with favorable toxicity and pharmacokinetic profile. We hypothesize that JAK3 inhibitors, especially JANEX-1, may prove useful to prevent or alleviate the symptoms of EMS.