Role of Eutopic Endometrium in Pelvic Endometriosis

D-chiro-inositol effectively counteracts endometriosis in a mouse model

BACKGROUND

Endometriosis, a common condition affecting 5-10% of women of reproductive age, is the growth of endometrial-like tissue outside the uterus, leading to pain and infertility. Current treatments, such as surgery and hormonal therapy, offer limited long-term benefits. This study investigated the potential of D-chiro inositol (DCI), a natural compound that influences ovarian steroidogenesis, to treat endometriosis and compared its efficacy with a progestin drug such as Dienogest (DG).

METHODS

We established a non-surgical mouse model of endometriosis in CD1 mice. Uterine horns were removed from donor mice, cut into fragments and inoculated in recipient mice by intraperitoneal injection. Endometriosis progression was assessed at 15, 21 and 28 days after transplantation, with the 28-day window being the most effective. The mice were then randomly assigned to four experimental groups, which received for 28 days: water (EMS); DCI 0.4 mg/die (DCI); DCI 0.2 mg/die and Dienogest 0.33 ng/die (DCI + DG); DG 0.67 ng/die (DG). At the end of the treatments, endometriotic lesions, ovaries and circulating estradiol levels were analyzed.

RESULTS

The results showed that treatment with DCI, both alone and in combination with DG, significantly reduced the number, size and vascularization of endometriotic lesions compared to the EMS control group. Histological analysis confirmed a decrease in endometriotic foci across all treatment groups, with the most pronounced effects in the DCI group. To investigate the underlying molecular mechanisms, we found that DCI led to a significant reduction in the expression of Sirt1 and an increase in E-Cadherin, indicating a reduction in EMT transition relevant for lesion development. In addition, DCI decreased cell proliferation and,blood vessel formation, as evaluated by PCNA and CD34, respectively. Futhermore, in the ovary, DCI treatment downregulated the expression of aromatase (Cyp19a1), the enzyme critical for estrogen biosynthesis, and increased the number of primordial to antral follicles, suggesting a beneficial effect on ovarian folliculogenesis.

CONCLUSIONS

By modulating proliferation, EMT transition and aromatase activity, DCI emerges as a promising compound for endometriosis treatment.

The matrix stiffness is increased in the eutopic endometrium of adenomyosis patients: a study based on atomic force microscopy and histochemistry

Previous ultrasound studies suggest that patients with adenomyosis (AM) exhibit increased uterine cavity stiffness, although direct evidence regarding extracellular matrix (ECM) content and its specific impact on endometrial stiffness remains limited. This study utilized atomic force microscopy to directly measure endometrial stiffness and collagen morphology, enabling a detailed analysis of the endometrium's mechanical properties: through this approach, we established direct evidence of increased endometrial stiffness and fibrosis in patients with AM. Endometrial specimens were also stained with Picrosirius red or Masson's trichrome to quantify fibrosis, and additional analyses assessed α-SMA and Ki-67 expression. Studies indicate that pathological conditions significantly influence the mechanical properties of endometrial tissue. Specifically, adenomyotic endometrial tissue demonstrates increased stiffness, associated with elevated ECM and fibrosis content, whereas normal endometrial samples are softer with lower ECM content. AM appears to alter both the mechanical and histological characteristics of the eutopic endometrium. Higher ECM content may significantly impact endometrial mechanical properties, potentially contributing to AM-associated decidualization defects and fertility challenges.

Transforming growth factor beta-1 (TGF-β1) expression in patients with adenomyosis

Objective

To compare Transforming growth factor beta-1 (TGF-β1) expression in patients with and without adenomyosis.

Methods

A prospective design was performed including 49 patients submitted to hysterectomy. Immunohistochemistry was performed on anatomopathological samples staged in paraffin blocks from patients with and without adenomyosis. The sample contained 28 adenomyosis cases and 21 controls. Student's t-test and multivariate logistic regression tests were used for statistical analysis. Associations were considered significant at p < 0.05.

Results

We found no significant association between adenomyosis and: smoking (p = 0.75), miscarriage (p = 0.29), number of previous pregnancies (p = 0.85), curettage (p = 0.81), pelvic pain (p = 0.72) and myoma (p = 0.15). However, we did find a relationship between adenomyosis and abnormal uterine bleeding (AUB) (p = 0.02) and previous cesarean section (p = 0.02). The mean TGF-β1 intensity (mean ± SD) in the ectopic endometrium of women with adenomyosis showed no significant association (184.17 ± 9.4 vs.184.66 ± 16.08, p = 0.86) from the topic endometrium of women without adenomyosis.

Conclusion

TGF-β1 expression was not increased in the ectopic endometrium of women with adenomyosis.

Kallikrein-Related Peptidase 4 Promotes Proliferation, Migration, Invasion, and Pro-Angiogenesis of Endometrial Stromal Cells via Regulation of Brain-Derived Neurotrophic Factor Production in Endometriosis

Endometriosis is a common benign gynecologic condition. Endometriosis lesions are associated with endometrial cell proliferation, migration, invasion, and neovascularization, while the specific molecular mechanisms are still elusive. Transcriptome sequencing has been used for the identification of diagnostic markers in endometriosis. Here, transcriptome profiling revealed that kallikrein-related peptidase 4 (KLK4) expression was up-regulated in ectopic endometrium (EC) tissues of patients with endometriosis. KLK4 mediates the degradation of extracellular matrix proteins, and its proteolytic activity activates many tumorigenic and metastatic pathways via tumor invasion and migration. Nevertheless, whether KLK4 serves as an important regulatory factor in endometriosis remains unclear. This study confirmed that KLK4 was highly expressed in ectopic endometrial stromal cells (EC-ESCs). KLK4 overexpression promoted proliferation and suppressed apoptosis of EC-ESCs, induced cell migration and invasion, and enhanced angiogenesis in vivo. Mechanistically, KLK4 overexpression mediated the protein cleavage of pro-brain-derived neurotrophic factor in EC-ESCs. Finally, brain-derived neurotrophic factor was a vital downstream substrate of KLK4 maintained the proliferation, metastasis, and pro-angiogenesis abilities and inhibited apoptosis of ESCs through a rescue study. Together, these findings demonstrate the promotive role of KLK4 in endometriosis development. In addition, the study provides a new insight that KLK4 might be a potential therapeutic target and prognostic marker for patients with endometriosis.

Endometrial polyps effect on pregnancy outcomes in infertile women with minimal/mild endometriosis: A retrospective study

OBJECTIVE

To assess the pregnancy outcomes and associated influencing factors of pregnancy after hysteroscopy combined with laparoscopy treatment in infertile patients with minimal/mild endometriosis.

DESIGN

A retrospective study.

SETTING

West China Second University Hospital of Sichuan University.

PATIENTS

We enrolled 898 infertile women who had their minimal/mild endometriosis lesions removed by laparoscopy, including 271 patients additionally diagnosed with endometrial polyps who also underwent hysteroscopic polypectomy.

METHODS

Based on the existence of endometrial polyps, patients with minimal/mild endometriosis were enrolled and divided into polyps group and non-polyps group.

MAIN OUTCOME MEASURES

Pregnancy outcomes.

RESULTS

A total of 271 women with minimal/mild endometriosis were included in polyps group while 491 women with minimal/mild endometriosis were included in non-polyps group. The pregnancy rate of polyps group was not statistically significant compared with non-polyp group (60.15% vs. 58.25%). The pregnancy rate was higher among patients with polyps ≥1 cm (76.06%, 54/71) than patients with polyps <1 cm (54.50%, 109/200) or patients without polyps (58.25%, 286/491) (p = 0.006). The pregnancy rate was higher for patients with multiple polyps (67.86%, 95/140) than for patients with single polyp (51.91%, 68/131) or without polyps (p = 0.025).

CONCLUSIONS

Among women with minimal/mild endometriosis, hysteroscopic polypectomy did significantly increase fertility in infertile patients with multiple polyps or size of polyp ≥1 cm compared with those without endometrial polyps, single polyp, and size of polyp <1 cm. The size and number of polyps were independently associated with the reproductive ability of women with minimal/mild endometriosis.

The Extracellular Vesicle-Macrophage Regulatory Axis: A Novel Pathogenesis for Endometriosis

Endometriosis (EMs) is a common disease among women whose pathogenesis is still unclear, although there are various hypotheses. Recent studies have considered macrophages the key part of the immune system in developing EMs, inducing inflammation, the growth and invasion of the ectopic endometrium, and angiogenesis. Extracellular vesicles (EVs) as novel intercellular vesicle traffic, can be secreted by many kinds of cells, including macrophages. By carrying long non-coding RNA (lncRNA), microRNA (miRNA), or other molecules, EVs can regulate the biological functions of macrophages in an autocrine and paracrine manner, including ectopic lesion growth, immune dysfunction, angiogenesis, and can further accelerate the progression of EMs. In this review, the interactions between macrophages and EVs for the pathogenesis of EMs are summarized. Notably, the regulatory pathways and molecular mechanisms of EVs secreted by macrophages during EMs are reviewed.

The Silent Threat to Women's Fertility: Uncovering the Devastating Effects of Oxidative Stress

Oxidative stress (OS), which arises through an imbalance between the formation of reactive oxygen species (ROS) and antioxidant defenses, plays a key role in the pathophysiology of female infertility, with the latter constituting just one of a number of diseases linked to OS as a potential cause. The aim of the present article is to review the literature regarding the association between OS and female infertility. Among the reproductive diseases considered are endometriosis and polycystic ovary syndrome (PCOS), while environmental pollutants, lifestyle variables, and underlying medical conditions possibly resulting in OS are additionally examined. Current evidence points to OS likely contributing to the pathophysiology of the above reproductive disorders, with the amount of damage done by OS being influenced by such variables as duration and severity of exposure and the individual's age and genetic predisposition. Also discussed are the processes via which OS may affect female fertility, these including DNA damage and mitochondrial dysfunction. Finally, the last section of the manuscript contains an evaluation of treatment options, including antioxidants and lifestyle modification, capable of minimizing OS in infertile women. The prime message underlined by this review is the importance of considering OS in the diagnosis and treatment of female infertility. Further studies are, nevertheless required to identify the best treatment regimen and its ideal duration.

Research advances in drug therapy of endometriosis

Endometriosis is one of the most common benign gynecological disorders in reproductive-aged women. The major symptoms are chronic pelvic pain and infertility. Despite its profound impact on women's health and quality of life, its pathogenesis has not been fully elucidated, it cannot be cured and the long-term use of drugs yields severe side effects and hinders fertility. This review aims to present the advances in pathogenesis and the newly reported lead compounds and drugs managing endometriosis. This paper investigated Genetic changes, estrogen-dependent inflammation induction, progesterone resistance, imbalance in proliferation and apoptosis, angiogenesis, lymphangiogenesis and neurogenesis, and tissue remodeling in its pathogenesis; and explored the pharmacological mechanisms, constitutive relationships, and application prospects of each compound in the text. To date, Resveratrol, Bay1316957, and bardoxifene were effective against lesions and pain in controlled animal studies. In clinical trials, Quinagolide showed no statistical difference with the placebo group; the results of phase II clinical trial of the IL-33 antibody have not been announced yet; clinical trial stage III of vilaprisan was suspended due to drug toxicity. Elagolix was approved for the treatment of endometriosis-related pain, but clinical studies of Elagolix for the pretreatment of patients with endometriosis to before In vitro fertilization treatment have not been fulfilled. The results of a clinical study of Linzagolix in patients with moderate to severe endometriosis-related pain have not been disclosed yet. Letrozole improved the fertility of patients with mild endometriosis. For endometriosis patients with infertility, oral GnRH antagonists and aromatase inhibitors are promising drugs, especially Elagolix and Letrozole.

The extracellular vesicular pseudogene LGMNP1 induces M2-like macrophage polarization by upregulating LGMN and serves as a novel promising predictive biomarker for ovarian endometriosis recurrence

STUDY QUESTION

How does ectopic endometrial stromal cell (Ecto-ESC)-derived extracellular vesicular Legumain pseudogene 1 (EV-LGMNP1), a newly identified pseudogene of Legumain (LGMN), contribute to M2-phenotype macrophage polarization, and does it predict recurrence in patients with ovarian endometriosis (EMs)?

SUMMARY ANSWER

EV-LGMNP1, which is abundant in Ecto-ESCs and serum from ovarian EMs, can direct macrophages towards an M2 phenotype by upregulating LGMN expression and is a promising biomarker for predicting ovarian EMs recurrence.

WHAT IS KNOWN ALREADY

Extracellular vesicles (EVs) can mediate cell-to-cell crosstalk to promote disease progression via cargo molecule transport. Recently, LGMNP1, a newly identified pseudogene of LGMN, has been reported to promote cancer progression by upregulating LGMN. LGMN is a well-studied protein that can induce M2-like polarization.

STUDY DESIGN, SIZE, DURATION

An in vitro study was conducted with Ecto-ESCs isolated from ectopic endometrial samples, collected from two patients with ovarian EMs (diagnosed by laparoscopy and histological analysis). A clinical retrospective cohort study of 52 ovarian EMs patients and 21 controls with available preoperative serum samples was carried out (2013-2017). The follow-up period ended either at the time of recurrence or on 31 December 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ecto-ESC-derived EVs (EV/Ecto-ESCs) were characterized by nanoparticle tracking analysis, transmission electron microscopy and western blotting. EV internalization by THP-1 cells, which are the most widely used primary human macrophages model, was detected by fluorescence labelling. After EV treatment, THP-1 cell polarization was detected by quantitative real-time PCR (qRT-PCR) and western blot analyses of CD86 (M1-related marker) and CD206 (M2-related marker). LGMNP1 mRNA expression level in EVs from both primary ectopic endometrioc stromal cells and serum was examined using qRT-PCR. Additionally, the expression of LGMN, the downstream target gene of LGMNP1, in THP-1 cells was evaluated using qRT-PCR and western blotting. Kaplan-Meier and multivariate Cox regression analyses were applied to evaluate the independent predictive factors of EMs recurrence-free survival. A novel nomogram model based on serum EV-LGMNP1 was then formulated to predict EMs recurrence.

MAIN RESULTS AND THE ROLE OF CHANCE

In vitro assays demonstrated that EV/Ecto-ESCs drove macrophages towards an M2-like phenotype. Moreover, LGMNP1 contributed to EV/Ecto-ESC-induced M2 macrophage polarization by upregulating LGMN mRNA expression levels. Clinically, serum EV-LGMNP1 was more highly expressed in recurrent EMs patients than in controls and EMs patients without recurrence. Survival analysis and our novel nomogram reconfirmed that serum EV-LGMNP1 was a novel promising and meaningful non-invasive biomarker for predicting EMs recurrence.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In vitro experiments were only performed on samples from two patients with ovarian endometriosis, and a larger sample size is needed. ESCs isolated from the eutopic endometrium of EMs and non-EMs patients should be studied in the future. Additionally, in vitro experiments should be performed using endometrial epithelium cells and further in vivo experiments, such as using mice endometriotic models to investigate whether EV/Ecto could induce M2 macrophage polarization, should be conducted. Moreover, multicentre, large-sample data are needed to validate our predictive nomogram model.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides novel insights into the mechanism of M2 polarization involved in ovarian EMs progression mediated by an 'EV-shuttled pseudogene LGMNP1' mode. In addition, serum EV-LGMNP1 may serve as a novel non-invasive biomarker for predicting recurrence, providing a new therapeutic target for ovarian EMs.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by funding from the National Natural Science Foundation of China (81971361), the Natural Science Foundation of Shanghai Science and Technology (19ZR1406900), the Shanghai 'Rising Stars of Medical Talent' Youth Development Program (AB83030002019004), the Clinical Research Plan of SHDC (SHDC2020CR4087), the Shanghai Municipal Health Commission (202040498), the Research and Innovation Project of the Shanghai Municipal Education Commission (2019-01-07-00-07-E00050) and the Clinical Research Plan of SHDC (SHDC2020CR1045B). There are no competing interests to declare.

Evidence for an Association Between Endometriosis and Allergic and Non-allergic Food Hypersensitivity Is Lacking

Endometriosis effects up to 1 in 9 women, and can be a severe and debilitating disease. It is suggested that there is a link between endometriosis and allergic hypersensitivities, including allergic and non-allergic food hypersensitivity. Best practice for managing endometriosis symptoms is holistic and includes broad multi-disciplinary care. Therefore, improving our understanding of common endometriosis comorbidities, including allergic and non-allergic food hypersensitivity, will assist in improving patient quality of life. This mini-review with systematic approach aims to explore the literature for evidence surrounding an association between endometriosis and allergic and/or non-allergic food hypersensitivity from the last 20 years. Of the 849 publications identified, five fulfilled the inclusion criteria. Only one publication reported a statistically significant increased risk for non-allergic food hypersensitivity in patients with endometriosis (P = 0.009), however, the endometriosis group was not uniform in diagnostic criteria and included individuals without laparoscopically visualized disease. No studies elucidated a statistically significant link between allergic food hypersensitivity alone and endometriosis. Therefore, based on a small number of studies with limited research quality, evidence does not support the existence of a link between endometriosis and allergic or non-allergic food hypersensitivity. Sufficiently powered evidence-based research is required, including information which better characterizes the patient's endometriosis symptoms, importantly the gastrointestinal sequalae, as well as specific allergic and non-allergic food hypersensitivities and method of diagnoses. Unequivocally confirming a link between endometriosis and food hypersensitivities is an essential step forward in dispelling the many myths surrounding endometriosis and improving management of disease.

Medical management of endometriosis

INTRODUCTION

Endometriosis is a benign gynecologic disorder that is defined as functional endometrial tissue outside of the uterine cavity. It is an estrogen-dependent, inflammatory disease that leads to symptoms of pelvic pain, dysmenorrhea, dyspareunia, and infertility, occurring in 6-10% of reproductive aged women. The severity of the disease ranges from asymptomatic to debilitating symptoms that have a major impact on women's lives. It is a chronic, recurrent disease, frequently requiring long term management until menopause and beyond. It is considered a chronic disorder that is managed with surgery, medical treatment, and oftentimes, both. Current medical therapy for endometriosis is considered suppressive of the disease, rather than curative. Fortunately, many patients do experience improvement and control of their symptoms with medical therapy. However, long-term efficacy of the medical treatments is often limited by side effects and the cost of therapy, and symptoms do tend to recur after discontinuation of these medications.

AREAS COVERED

This review summarizes our understanding of the pathogenesis of endometriosis and provides more in-depth discussion of specific medical management options used to treat endometriosis, including mechanism of action and side effects. It also provides recommendations on strategy with a forward look to novel endometriosis treatments in the future.

EXPERT OPINION

The authors emphasize that endometriosis is a chronic disorder requiring long term medical therapy. Early diagnosis of endometriosis is key in preventing severe, debilitating symptoms and progression of disease. By utilizing our current knowledge of the pathophysiology of endometriosis and by correctly implementing currently available medical and surgical therapies we can significantly reduce the physical, psychosocial and financial burden of this chronic, recurrent and indolent disease. Current available medications are suppressive therapies, but the authors are looking forward to future therapies that can effectively cure or at least control endometriosis with minimal side effects. Future research should continue to look for the genetic trigger for endometriosis which can lead us to its underlying pathogenesis and eventually a cure or prevention.

The pathogenesis of endometriosis: clues from the immunological evidence

INTRODUCTION

Endometriosis pathogenesis is still a matter of debate. It is now agreed that a complex cooperation of genetic, hormonal, immune and environmental factors is implicated. However, no consensus has been reached yet on what firstly is responsible for the initiation, promotion and survival of endometrial-like tissue outside the uterine cavity. Since consistent evidence have found immunological alterations in women with the disease, the impairment of immune system has been considered for decades one of the possible causes of endometriosis. The aim of this literature review is to summarize the available findings on a particular aspect of this topic represented by the inhibition of natural killer (NK) cell activity in women affected as a paradigmatic example of the complexity in studying the pathogenesis of endometriosis.

EVIDENCE ACQUISITION

Advanced search of PubMed for English articles published between 1990 and September 2020 using the keywords "endometriosis" or "endometrioma" or "endometriotic" or "ectopic endometrium" in combination with "natural killer cells" (NK).

EVIDENCE SYNTHESIS

Consistent studies have found an impairment in NK cell activity in women with endometriosis especially in advanced stages of disease (stage III/IV). Reports to explain these findings support the phenomenon as a consequence of the disease establishment. Evidence from genetic studies have questioned the role of these dysfunctions in the pathogenesis of the disease.

CONCLUSIONS

Immunological dysfunctions and the decreased NK cell cytotoxicity may only represent consequence of endometriosis, although the underlining mechanisms still need to be elucidated.

Eutopic endometrium from women with endometriosis and chlamydial endometritis share immunological cell types and DNA repair imbalance: A transcriptome meta-analytical perspective

The aim of this study was to identify the key similarities between the eutopic endometrium of women with endometriosis and chlamydia-induced endometritis taking into account tissue microenvironment heterogeneity, transcript gene profile, and enriched pathways. A meta-analysis of whole transcriptome microarrays was performed using publicly available data, including samples containing both glandular and stromal endometrial components. Control samples were obtained from women without any reported pathological condition. Only samples obtained during the proliferative menstrual phase were included. Cellular tissue heterogeneity was predicted using a method that integrates gene set enrichment and deconvolution approaches. The batch effect was estimated by principal variant component analysis and removed using an empirical Bayes method. Differentially expressed genes were identified using an adjusted p-value < 0.05 and fold change = 1.5. The protein-protein interaction network was built using the STRING database and interaction score over 400. The Molecular Signatures Database was used to analyse the functional enrichment analysis. Both conditions showed similarities in cell types in the microenvironment, particularly CD4⁺ and CD8⁺ Tem cells, NKT cells, Th2 cells, basophils, and eosinophils. With regards to the regulation of cellular senescence and DNA integrity/damage checkpoint, which are commonly enriched pathways, 21 genes were down-regulated and directly related to DNA repair. Compared to the endometriosis samples, some chlamydial endometritis samples presented a lack of enriched immune pathways. Our results suggest that both conditions show similar distributions of microenvironment cell types, the downregulation of genes involved in DNA repair and cell cycle control, and pathways involved in immune response evasion.

Histomorphological and Functional Features of the Eutopic Endometrium in Patients with Ovarian Endometriosis After Surgery-a Clinical Study

Endometriosis causes infertility and the alterations in endometrial receptivity. Pinopodia in eutopic endometrial epithelium may have significant implications in the endometriosis-associated infertility. The aim of this study is to ascertain whether the surgical interventions to remove endometrioid ovarian cysts (EOCs) can improve endometrial receptivity. The study included 172 patients of reproductive age with EOC, who underwent laparoscopic cystectomy. Aspiration endometrial biopsy was performed at 6 and 12 months after the surgery during the proliferation and secretion phases. Histopathology analysis included H&E staining and IHC. Morphometric studies were performed on endometrial biopsies collected during the proliferation phase of 28 patients, and the secretion phase of 12 patients. The expression of IHC markers for estrogen receptors (ER) and progesterone receptors (PR) and the percentage of cells containing pinopodia were determined. A significant increase in the ER and PR expression was observed in the epithelium during the "middle stage, proliferation phase" and in the stroma and glands during "middle stage, secretion phase". A delay in endometrial secretory transformation and statistically significant decrease in the number of pinopodia was observed on the apical surface of the cells. These structural and functional alterations were observed both at 6 and 12 months after cystectomy. The endometriosis-associated infertility after surgical intervention of EOC could be due to the extensive expression of ER and PR during the proliferation and secretion phases, as well as the delayed secretory transformation and impaired formation of pinopodia in the eutopic endometrium in the patients at 6 and 12 months after surgery.

FACTORS OF ENDOMETRIAL RECEPTIVITY DOWN-REGULATION IN GENITAL ENDOMETRIOSIS

Endometriosis, or endometrioid disease, is a chronic estrogen-dependent gynecological disease caused by ectopic localization of endometrial tissue, mainly in the pelvis and ovaries. However, at the present stage of development of reproductive medicine, the classical topographic definition of endometriosis should be expanded with new significant characteristics established using the achievements of cell and molecular biology, which allowed a more detailed study of the pathogenesis of this disease. In addition, the introduction of personalized approaches to the treatment of patients with endometriosis and infertility, more attention should be paid to the search for disease predictors and the formation of risk groups with the observation of patients from puberty to menopause. In this review, we have analyzed the literature data and our own studies with an emphasis on factors and markers of decreased receptivity of eutopic endometrium in women with endometriosis, as well as pain, the manifestations of which can contribute to the exact diagnosis of external genital endometriosis.

Macrophages alternatively activated by endometriosis-exosomes contribute to the development of lesions in mice

STUDY QUESTION

Do exosomes play a role in the pathogenesis of endometriosis in a murine model?

SUMMARY ANSWER

Exosomes from endometriosis (EMS) can alternatively activate macrophages and thus contribute to the development of lesions in mice.

WHAT IS KNOWN ALREADY

The pathogenesis of endometriosis, an inflammatory disease, possibly involves peritoneal macrophages. Exosomes are recognized as a new communicator among cells and a key modulator in several inflammatory diseases.

STUDY DESIGN, SIZE, DURATION

We performed in vitr and in vivo experiments to demonstrate the role of exosomes in modulating macrophages. RAW264.7 cells (macrophages) were used to examine the effects of exosomes on macrophages in vitro. An experiment was also conducted in vivo, as follows. Fifty C57BL/6 female mice were randomly allocated to five control and five experimental groups (n = 5/group). The experimental group was injected i.p. with EMS-exosomes derived from eutopic stromal cells, starting on Day-7 then every day for 1 week. The control group received CON-exosomes from mice without endometriosis. Peritoneal macrophages were assessed over the next 6 days. On Day 0, all mice were injected i.p. with endometrium to establish the endometriosis model. On Day 14, all mice were sacrificed, ectopic lesions were counted and measured.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Exosomes were isolated from endometrial stromal cells (ESCs) by ultracentrifugation and characterized through transmission electron microscopy, nanoparticle tracking analysis and western blot. After treatment with exosomes, the polarization and phagocytic ability of the macrophages were detected by flow cytometry analysis, immunofluorescent staining and RT-PCR. C57BL/6 mice were utilized to establish an endometriosis model by i.p. injection of endometrial segments.

MAIN RESULTS AND THE ROLE OF CHANCE

After treatment with EMS-exosomes, the macrophages were polarized into an M2-like phenotype and their phagocytic ability decreased (P < 0.05 versus treatment with CON-exosomes). The total weight and volume of the lesions in mice treated with EMS-exosomes significantly increased compared with those in mice treated with CON-exosomes (P < 0.05). The infiltration of M2-like macrophages was enhanced in the EMS-exosome group (P < 0.001 versus treatment with CON-exosomes).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Detection of endometriosis following exosome treatment was only performed in a murine endometriosis model. Clinical data and additional mechanism studies must be conducted to understand the role of exosomes in the pathogenesis of endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

This study emphasizes the importance of EMS-exosomes in the pathogenesis of endometriosis. Further investigations on the exosome signaling pathways may contribute to the development of effective treatments for endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by grants (Nos. 81571417 and 81771552) from the National Science Foundation of China. The authors report no conflict of interest.

Knockdown of vascular cell adhesion molecule 1 impedes transforming growth factor beta 1-mediated proliferation, migration, and invasion of endometriotic cyst stromal cells

PURPOSE

Endometriosis is one of the most common, difficult, and complicated gynecological disorders. Vascular cell adhesion molecule 1 (VCAM-1) has been reported to be aberrantly expressed in patients with endometriosis. However, the exact role and mechanism of VCAM-1 in endometriosis remains unclear.

METHODS

The expression of transforming growth factor beta 1 (TGF-β1) and VCAM-1 was determined by quantitative real-time polymerase chain reaction and western blotting. Human endometriotic cells were cultured and their responsiveness to TGF-β1 was evaluated by Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, and transwell migration and invasion assays.

RESULTS

The levels of TGF-β1 and VCAM-1 mRNA were upregulated in the endometriotic tissues. Knockdown of TGF-β1 in endometriotic cyst stromal cells caused a marked inhibition of cell proliferation, migration, and invasion. Treatment of endometriotic cyst stromal cells with TGF-β1 resulted in an obvious promotion of cell proliferation, migration, and invasion, and strikingly increased the protein expression of VCAM-1. Silencing of Smad3 abated TGF-β1-stimulated VCAM-1 expression. Furthermore, the promoting effects of TGF-β1 on the proliferation, migration, and invasion of endometriotic cyst stromal cells were blocked by silencing of VCAM-1.

CONCLUSION

Knockdown of VCAM-1 impedes TGF-β1-mediated proliferation, migration, and invasion of endometrial cells, thereby indicating that VCAM-1 may serve as a therapeutic target for endometriosis.

Expression of the TFDP1 gene in the endometrium of women with deep infiltrating endometriosis

The field of endometriosis etiopathogenesis aims to identify the origin of disease in endometrial disorders. Changes in gene and protein expression related to cell adhesion, collagenases, and, mainly, cell cycle regulators have been identified. We set out to analyze the expression of the transcription factor DP-1 (TFDP1) gene, which encodes a protein that controls the G1/S phase passage of the cell cycle, in the endometrium of women with deep infiltrating endometriosis (DIE). Samples of endometrium from both endometriosis-affected women and healthy women were collected, cultured and maintained at the Cell Bank of the Pelvic Pain and Endometriosis Unit of the Federal University of Sao Paulo. This study analyzed five samples from the endometrium cell culture of healthy patients (i.e. no pelvic disease, as determined by means of laparoscopic tubal ligation) and six samples from women diagnosed with DIE. Samples were evaluated for TFDP1 gene expression by real-time PCR. We observed a downregulation of TFDP1 in the endometrium cells of women with DIE when compared to the control (a fold-change of -2.05, p value=.011). The TFDP1 gene is part of the cell cycle pathway, but its function is not yet clear. Additional studies are necessary to clarify the function of TFDP1 in endometriosis etiopathogenesis.

Pathogenesis of endometriosis: the genetic/epigenetic theory

OBJECTIVE

To study the pathophysiology of endometriosis.

DESIGN

Overview of observations on endometriosis.

SETTING

Not applicable.

PATIENT(S)

None.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The hypothesis is compatible with all observations.

RESULT(S)

Endometriosis, endometrium-like tissue outside the uterus, has a variable macroscopic appearance and a poorly understood natural history. It is a hereditary and heterogeneous disease with many biochemical changes in the lesions, which are clonal in origin. It is associated with pain, infertility, adenomyosis, and changes in the junctional zone, placentation, immunology, plasma, peritoneal fluid, and chronic inflammation of the peritoneal cavity. The Sampson hypothesis of implanted endometrial cells following retrograde menstruation, angiogenic spread, lymphogenic spread, or the metaplasia theory cannot explain all observations if metaplasia is defined as cells with reversible changes and an abnormal behavior/morphology due to the abnormal environment. We propose a polygenetic/polyepigenetic mechanism. The set of genetic and epigenetic incidents transmitted at birth could explain the hereditary aspects, the predisposition, and the endometriosis-associated changes in the endometrium, immunology, and placentation. To develop typical, cystic ovarian or deep endometriosis lesions, a variable series of additional transmissible genetic and epigenetic incidents are required to occur in a cell which may vary from endometrial to stem cells. Subtle lesions are viewed as endometrium in a different environment until additional incidents occur. Typical cystic ovarian or deep endometriosis lesions are heterogeneous and represent three different diseases.

CONCLUSION(S)

The genetic epigenetic theory is compatible with all observations on endometriosis. Implications for treatment and prevention are discussed.

Curcumin attenuates proangiogenic and proinflammatory factors in human eutopic endometrial stromal cells through the NF-κB signaling pathway

Endometriosis is a chronic gynecological inflammatory disorder in which immune system dysregulation is thought to play a role in its initiation and progression. Due to altered sex steroid receptor concentrations and other signaling defects, eutopic endometriotic tissues have an attenuated response to progesterone. This progesterone-resistance contributes to lesion survival, proliferation, pain, and infertility. The current agency-approved hormonal therapies, including synthetic progestins, GnRH agonists, and danazol are often of limited efficacy and counterproductive to fertility and cause systemic side effects due to suppression of endogenous steroid hormone levels. In the current study, we examined the effects of curcumin (CUR, diferuloylmethane), which has long been used as an anti-inflammatory folk medicine in Asian countries for this condition. The basal levels of proinflammatory and proangiogenic chemokines and cytokines expression were higher in primary cultures of stromal cells derived from eutopic endometrium of endometriosis (EESC) subjects compared with normal endometrial stromal cells (NESC). The treatment of EESC and NESC with CUR significantly and dose-dependently reduced chemokine and cytokine secretion over the time course. Notably, CUR treatment significantly decreased phosphorylation of the IKKα/β, NF-κB, STAT3, and JNK signaling pathways under these experimental conditions. Taken together, our findings suggest that CUR has therapeutic potential to abrogate aberrant activation of chemokines and cytokines, and IKKα/β, NF-κB, STAT3, and JNK signaling pathways to reduce inflammation associated with endometriosis.

Estrogen restricts the apoptosis of endometrial stromal cells by promoting TSLP secretion

Endometriosis (EMS) is a female hormone‑ dependent disease with controversial reports of its etiology and pathogenesis. Apoptosis is particularly important in the human endometrium due to the dynamic cycles of proliferation and shedding. Estrogen possessed antiapoptotic effects on endometrial stromal cells (ESCs), which appears to be exacerbated in women with EMS; however, the underlying mechanism of the antiapoptotic effects of estrogen on ESC remains unknown. The present study aimed to determine whether estrogen regulates the apoptosis of ESCs via thymic stromal lymphopoietin (TSLP) and the associated mechanism. An ELISA was conducted to detect TSLP content in the ESC culture medium treated with estrogen. Subsequently, the early apoptotic rate and expression of B‑cell lymphoma (Bcl‑2) of ESCs were analyzed by flow cytometry in the presence of recombinant human TSLP, anti‑human TSLP neutralizing antibody or estrogen. In the present study, it was reported that ESCs exhibited basal TSLP secretion in the absence of estrogen as reported in previous studies, and that estrogen promoted TSLP secretion of ESCs in a dose‑dependent manner. The results demonstrated that estrogen suppressed the apoptosis of ESCs associated with the promotion of Bcl‑2 expression, which may be partly reversed by inhibiting TSLP. Therefore, the findings of the present study revealed a novel mechanism of estrogen‑dependent apoptotic suppression of ESCs associated with TSLP secretion and Bcl‑2 regulation. Endogenous and estrogen‑induced endometrial TSLP may promote the initiation and development of EMS via the inhibition of apoptosis.

Metabolomics reveals perturbations in endometrium and serum of minimal and mild endometriosis

Endometriosis is a common benign gynecological disease, characterized by growth and proliferation of endometrial glands and stroma outside the uterus. With studies showing metabolic changes in various biofluids of endometriosis women, we have set upon to investigate whether endometrial tissue show differences in their metabolic profiles. ¹H NMR analysis was performed on eutopic endometrial tissue of women with endometriosis and controls. Analysis was performed on spectral data and on relative concentrations of metabolites obtained from spectra using multivariate and univariate data analysis. Analysis shows that various energy, ketogenic and glucogenic metabolites have significant altered concentrations in various stages of endometriosis. In addition, altered tissue metabolites in minimal and mild stages of endometriosis were explored in serum of these patients to assess their role in disease diagnosis. For Stage I diagnosis alanine was found to have 90% sensitivity (true positives) and 58% specificity (true negatives). For Stage II diagnosis alanine, leucine, lysine, proline and phenylalanine showed significant altered levels in serum. While sensitivity of these serum metabolites varied between 69.2–100% the specificity values ranged between 58.3–91.7%. Further, a regression model generated with this panel of serum markers showed an improved sensitivity and specificity of 100% and 83%, respectively for Stage II diagnosis.

Management of Chronic Pelvic Pain

The management of chronic pelvic pain poses a significant challenge to both physicians and patients. Patients should be evaluated for both gynecologic and nongynecologic conditions, and >1 source may be identified. Treatment involves medical as well as surgical options, and it is important to set realistic goals with patients. Treatment may not be curative, but should improve the patient's quality of life.

Endometriosis-associated ovarian neoplasia

This article reviews the most relevant pathological and molecular features of ovarian tumours that are associated with endometriosis. Endometriosis is a common condition, affecting 5-15% of all women, and it has been estimated that 0.5-1% of cases are complicated by neoplasia. The most common malignant tumours in this setting are endometrioid adenocarcinoma and clear cell adenocarcinoma, each accounting for approximately 10% of ovarian carcinomas in Western countries. A minority of cases are associated with Lynch syndrome. These carcinomas are often confined to the ovaries at presentation in which case they have relatively favourable outcomes. However, high-stage tumours, particularly clear cell carcinomas, generally have a poor prognosis and this partly reflects relative resistance to current treatment. Histological diagnosis is straightforward in the majority of cases but some variants, for example endometrioid carcinomas with sex cord-like appearances or oxyphil cells, may create diagnostic difficulty. Similarly, clear cell carcinomas can show a range of architectural and cytological patterns that overlap with other tumours, both primary and metastatic, involving the ovaries. Endometriosis-associated borderline tumours are less common, and they often show mixed patterns of differentiation (seromucinous tumours). Atypical endometriosis may represent an intermediate step in neoplastic progression and some of these lesions demonstrate immunohistological and molecular alterations similar to those observed in endometriosis-related tumours. ARID1A mutations are relatively common in all of these tumours, but each has additional characteristic molecular alterations which are likely to be of increasing clinical relevance as targeted therapies are developed. Less is known of the pathogenesis of rarer endometriosis-associated ovarian tumours including endometrioid stromal sarcoma, mesodermal (Müllerian) adenosarcoma, and carcinosarcoma. This article also briefly reviews the issue of synchronous endometrioid carcinomas of the endometrium and the ovary, including the most recent developments on pathogenesis.

Endometriosis, especially mild disease: a risk factor for miscarriages

OBJECTIVE

To investigate the prevalence of miscarriage in women with endometriosis (WwE) compared with disease-free control women (CW).

DESIGN

Cross-sectional analysis nested in a retrospective observational study (n = 940).

SETTING

Hospitals and associated private practices.

PATIENT(S)

Previously pregnant women (n = 268) within reproductive age in matched pairs.

INTERVENTION(S)

Retrospective analysis of surgical reports and self-administered questionnaires.

MAIN OUTCOME MEASURE(S)

Rate of miscarriage, subanalysis for fertility status (≤12 vs. >12 months' time to conception), endometriosis stages (revised American Society of Reproductive Medicine classification [rASRM] I/II vs. III/IV) and phenotypic localizations (superficial peritoneal, ovarian, and deep infiltrating endometriosis).

RESULT(S)

The miscarriage rate was higher in WwE (35.8% [95% confidence interval 29.6%-42.0%]) compared with CW (22.0% [16.7%-27.0%]); adjusted incidence risk ratio of 1.97 (95% CI 1.41-2.75). This remained significant in subfertile WwE (50.0% [40.7%-59.4%]) vs. CW (25.8% [8.5%-41.2%]) but not in fertile WwE (24.5% [16.3%-31.6%]) vs. CW (21.5% [15.9%-26.8%]). The miscarriage rate was higher in women with milder forms (rASRM I/II 42.1% [32.6%-51.4%] vs. rASRM III/IV 30.8% [22.6%-38.7%], compared with 22.0% [16.7%-27.0%] in CW), and in women with superficial peritoneal endometriosis (42.0% [32.0%-53.9%]) compared with ovarian endometriosis (28.6% [17.7%-38.7%]) and deep infiltrating endometriosis (33.9% [21.2%-46.0%]) compared with CW (22.0% [16.7%-27.0%]).

CONCLUSION(S)

Mild endometriosis, as in superficial lesions, is related to a great extent of inflammatory disorder, possibly leading to defective folliculogenesis, fertilization, and/or implantation, presenting as increased risk of miscarriage.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02511626.

Autophagy in endometriosis: Friend or foe?

Endometriosis is a chronic, estrogen-dependent disease and characterized by the implantation of endometrial glands and stroma deep and haphazardly into the outside the uterine cavity. It affects an estimated 10% of the female population of reproductive age and results in obvious reduction in health-related quality of life. Unfortunately, there is no a consistent theory for the etiology of endometriosis. Furthermore, the endometriosis is hard to diagnose in early stage and the treatment methods are limited. Importantly, emerging evidence has investigated that there is a close relationship between endometriosis and autophagy. However, autophagy is a friend or foe in endometriosis is puzzling, the precise mechanism underlying autophagy in endometriosis has not been fully elucidated yet. Here, we provide an integrated view on the acquired findings of the connections between endometriosis and autophagy. We also discuss which may contribute to the abnormal level of autophagy in endometriosis.

Prostaglandin levels, vaginal innervation, and cyst innervation as peripheral contributors to endometriosis-associated vaginal hyperalgesia in rodents

Endometriosis is a painful condition characterized by growth of endometrial cysts outside the uterus. Here, we tested the hypothesis that peripheral innervation and prostaglandin levels contribute to endometriosis-associated pain. Female Sprague-Dawley rats (n = 16) were surgically instrumented by transplanting uterine tissue onto mesenteric arteries within the peritoneal cavity to create a model of endometriosis which forms extra-uterine endometrial cysts and vaginal hyperalgesia. Our results describe a significant positive correlation between endometriosis-induced vaginal hyperalgesia and cyst innervation density (sensory, r = 0.70, p = 0.003; sympathetic, r = 0.55, p = 0.03), vaginal canal sympathetic innervation density (r = 0.80, p = 0.003), and peritoneal fluid levels of the prostaglandins PGE2 (r = 0.65, p = 0.01) and PGF2α (r = 0.63, p = 0.02). These results support the involvement of cyst innervation and prostaglandins in endometriosis-associated pain. We also describe how sympathetic innervation density of the vaginal canal is an important predictor of vaginal hyperalgesia.

Role of Versican in the Pathogenesis of Peritoneal Endometriosis

CONTEXT

Sampson's theory cannot explain why only some cycling women develop peritoneal endometriosis. Few studies have focused on the pelvic peritoneum, which receives regurgitated endometrial tissues. We hypothesized that molecular alterations in the peritoneum are involved in the development of peritoneal endometriosis and conducted a microarray analysis to compare macroscopically normal peritoneum sampled from women with peritoneal endometriosis (endometriotic peritoneum) and those without (non-endometriotic peritoneum). Versican, a major proteoglycan component of the extracellular matrix, is one of the molecules up-regulated in endometriotic peritoneum.

OBJECTIVE

To investigate the role of versican in peritoneal endometriosis. Design, Patients, and Main Outcome Measure: Endometriotic peritoneum and non-endometriotic peritoneum were subjected to RT-PCR, immunostaining, and Western blotting. The versican V1 isoform was stably transfected into Chinese hamster ovary cells (CHO-V1), and the effects of CHO-V1-derived conditioned medium (V1-CM) on primary human endometrial stromal cells were investigated with attachment, invasion, and proliferation assays. The effects of peritoneal fluid collected from endometriotic women (endometriotic PF) or cytokines/growth factors, which were shown to be elevated in endometriotic PF, on versican expression in a human peritoneal cell line (HMrSV5) were also examined.

RESULTS

Versican V1 expression levels were significantly higher in endometriotic peritoneum. In vitro, V1-CM promoted attachment to the HMrSV5 cell monolayer as well as the Matrigel invasion of endometrial stromal cells. Although versican V1 expression was up-regulated by TGF-β1 in HMrSV5 cells, it remained unchanged in endometriotic PF.

CONCLUSIONS

Our results suggest the involvement of peritoneal versican in the development of peritoneal endometriosis.

Syndecan-4 expression is upregulated in endometriosis and contributes to an invasive phenotype

OBJECTIVE

To study the expression and function of syndecan-4 in endometriosis.

DESIGN

Histopathological investigation of eutopic endometrium and experimental laboratory study on a cell line derived from epithelial endometriotic cells (12Z).

SETTING

University hospital laboratory.

PATIENT(S)

One hundred six women (62 controls/44 endometriosis) from the IVF center of Münster University Hospital aged 23-44 undergoing Pipelle biopsy and diagnostic exploratory laparoscopy.

INTERVENTION(S)

Eutopic endometrial tissue was investigated by immunohistochemistry for the expression of syndecan-4. The human endometriotic cell line 12Z was transiently transfected with syndecan-4 small interfering RNA and investigated for changes in cell behavior.

MAIN OUTCOME MEASURE(S)

Syndecan-4 expression in eutopic endometrium was evaluated immunohistochemically in endometrial glands and stroma. Scoring results were correlated with the stages of the menstrual cycle and presence or absence of endometriosis. Quantitative polymerase chain reaction was used to measure syndecan-4-dependent expression changes of MMP2, MMP3, MMP9, Rac1, and ATF2. Altered cell behavior was monitored by matrigel invasion assays and cell viability assays.

RESULT(S)

Syndecan-4 expression was significantly higher in the glands and stroma of patients with endometriosis compared with controls, whereas no menstrual cycle-dependent expression was observed. In 12Z cells, syndecan-4 depletion did not affect cell viability but resulted in a significantly reduced matrigel invasiveness and reduced expression of the small GTPase Rac1, the transcription factor ATF-2, and MMP3.

CONCLUSION(S)

The upregulation of syndecan-4 in the eutopic endometrium of endometriosis patients may facilitate the pathogenetic process by promoting invasive cell growth via Rac1, MMP3, and ATF-2.

Aromatase inhibitors in the treatment of endometriosis

Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis.

Ultrastructural Features of Eutopic Endometrium in a Rat Model of Endometriosis

Endometriosis is a chronic recurrent disease that is relatively common. Diagnosis is difficult and often delayed. Current treatments are inadequate with unacceptable side effects and multiple surgeries may be needed. Abnormal eutopic endometrium may play important role in endometriosis-associated infertility. This study aimed to examine the ultrastructural changes in eutopic endometrium in a rat model of surgically induced endometriosis. Endometrial tissue was removed from rats in surgical endometriosis induction group (n = 10), sham operated (n = 10) and non-operated control (n = 10) groups in the diestrus phase of the estrus cycle. They were studied with light, transmission and scanning electron microscope as well as morphometric analysis. Eutopic endometrium in surgically induced endometriosis showed pseudostratified epithelium, vacuolated columnar cells alternated with dark cells. The stroma was edematous exhibiting dilated, congested blood vessels. The mean endometrial mucosal depth and surface epithelial height significantly increased. Ultrastructurally, most luminal epithelial cells showed vacuolation. Mucous secretory granules were surrounded by dilated rough endoplasmic reticulum cisternae. Mitochondria, glycogen deposits and vesicles with electron dense cores were observed. The nuclei were highly euchromatic. Well defined microvilli were noticed with evident apical tight junctions. Scanning electron microscope revealed flattened and structurless surface epithelium with apparent decrease in the number of pinopodes. A different response to sex hormones in different parts of eutopic endometrium was observed. Ultrastructural features of estrogen dominance or progesterone resistance in the eutopic endometrium might account for inappropriate cyclic changes occurring in the disease.

Magnetic resonance imaging evidence for perineural spread of endometriosis to the lumbosacral plexus: report of 2 cases

Sciatic nerve endometriosis (EM) is a rare presentation of retroperitoneal EM. The authors present 2 cases of catamenial sciatica diagnosed as sciatic nerve EM. They propose that both cases can be explained by perineural spread of EM from the uterus to the sacral plexus along the pelvic autonomie nerves and then further distally to the sciatic nerve or proximally to the spinal nerves. This explanation is supported by MRI evidence in both cases. As a proof of concept, the authors retrieved and analyzed the original MRI studies of a case reported in the literature and found a similar pattern of spread. They believe that the imaging evidence of their institutional cases together with the outside case is a very compelling indication for perineural spread as a mechanism of EM of the nerve.

Emerging therapy for endometriosis

INTRODUCTION

Endometriosis is a chronic disease manifested by pain and infertility due to ectopic implantation of endometrial glands and stroma causing inflammation. Treatment of endometriosis utilizes a significant amount of health-care resources and requires chronic therapy. Management involves a combination of surgical and medical interventions and requires long-term treatment to avoid repeated surgeries.

AREAS COVERED

Whereas medical therapies exist for management of endometriosis-related pain, each class has its limitations including side effects, cost, and known duration of relief of symptoms. Development of effective, well-tolerated medical therapies that are appropriate for long-term use is crucial to provide adequate treatment for this chronic disease. This review discusses the various medical therapies available, their limitations, and emerging therapies being developed to address many of these concerns.

EXPERT OPINION

The authors recommend chronic suppressive therapy for management of endometriosis symptoms, particularly in the postoperative setting. Empiric treatment is appropriate for those patients without evidence of severe disease. Currently available option may not be effective for nor tolerated by all patients. Newer compounds, including gonadotropin-releasing antagonists and aromatase inhibitors combined with hormonal contraceptives, offer possible alternatives to currently available therapies.

Deep Invasive Endometriosis Lesions of the Rectosigmoid May Be Related to Alterations in Cell Kinetics

OBJECTIVES

The aim of this study was to analyze cell kinetics through expression and apoptosis of topoisomerase 2-α (TOP2A), p53, and c-erb2 in rectosigmoid endometriotic lesions and in healthy endometrial tissue and to establish correlations between such findings and clinical data in patients with rectosigmoid endometriosis.

METHODS

Sixty patients with rectosigmoid endometriosis and 20 control women without endometriosis were included. Immunohistochemical assays were used to measure expression of TOP2A, p53, and c-erB-2. Apoptosis was quantified by directly counting the apoptotic bodies.

FINDINGS

The number of lesions was positively correlated with expression of TOP2A in the lesion. There was also significant correlation between the lesions' size and number and cell turnover index. Apoptosis index (AI) was the same for endometriosis lesions and eutopic endometrium. Expression of TOP2A was significantly lower in the endometriosis group compared to the controls.

CONCLUSIONS

Changes in cell proliferation but not in the AI in rectosigmoid endometriosis are indicative of an imbalance in cell kinetics that may lead to the development of the disease.

Potential role of aromatase inhibitors in the treatment of endometriosis

Endometriosis is an estrogen-dependent chronic inflammatory disease affecting 5%–10% of reproductive-age women, with a prevalence of 5%–50% in infertile women and >33% of women with chronic pelvic pain. Third-generation aromatase inhibitors (AIs) are approved adjuvants for the treatment of estrogen receptor-positive breast cancer. Molecular studies have revealed the presence of aromatase P450, the key enzyme in the biosynthesis of ovarian estradiol, inside the endometriotic tissue, indicating local synthesis of estradiol. Thereby, AIs represent an appealing medical option for the management of different aspects of this enigmatic disease, especially pelvic pain and infertility. Accordingly, this review aims to evaluate the potential role of AIs in the treatment of endometriosis-associated symptoms, mainly pain and infertility. Notably, several studies have demonstrated that the combination of AIs with conventional therapy as oral contraceptive pills, progestins, or gonadotropin-releasing hormone analogs can be used to control endometriosis-associated pain and pain recurrence in premenopausal women, particularly those with pain due to rectovaginal endometriosis refractory to other medical or surgical treatment. Some case reports have shown promising results in the treatment of postmenopausal endometriosis as first-line treatment, when surgery is contraindicated, or as second-line treatment in the case of postoperative recurrence. Third-generation AIs, especially letrozole, have challenged clomiphene citrate as an ovulation-induction agent in patients with polycystic ovary syndrome and in cases of unexplained infertility. However, few studies are available regarding the use of AIs to treat endometriosis-associated infertility. Therefore, larger multicenter randomized trials using AIs for the treatment of endometriosis-associated infertility are needed to clarify its effect. The safety of AIs for ovulation induction or superovulation has generated a lively discussion. Data from recent retrospective and prospective studies have supported its safety.

Treatment with bazedoxifene and conjugated estrogens results in regression of endometriosis in a murine model

Bazedoxifene (BZA), a selective estrogen receptor modulator (SERM), inhibits the action of estrogens on endometrial proliferation. Here, we evaluate the effect of a tissue-selective estrogen complex (TSEC) containing BZA and conjugated estrogens (CE) on ectopic endometrial lesions in a mouse model of endometriosis. Experimental endometriosis was created in 60 female CD-1 mice. The mice were randomly divided into 10 groups that received varying doses of either BZA (1, 2, 3, or 5 mg/kg/day), BZA (1, 2, 3, or 5 mg/kg/day) in combination with CE (3 mg/kg/day), CE treatment alone (3 mg/kg/day), or vehicle control for 8 wk. Treatment with BZA alone or the TSEC containing BZA/CE led to a decrease in endometriotic lesion size compared to controls. The mean surface area of the untreated lesions was 19.6 mm(2). Treatment with BZA or BZA/CE resulted in reduced lesion size (to 8.8 and 7.8 mm(2), respectively). No significant difference was found in lesion size between the BZA and BZA/CE treatment groups or between different doses of either treatment. Ovarian cyst formation was not evident in the treated groups. Treatment with the TSEC containing higher BZA dosages (3 and 5 mg/kg/day) led to significantly lower levels of estrogen receptor (Esr1) mRNA expression compared to the control treatment. No differences were observed in expression of progesterone receptor (Pgr). Immunohistochemical analysis also demonstrated a decrease in ESR protein. The combination of CE and BZA may prove to be a novel treatment option for endometriosis.

Adolescent Endometriosis: Review of Clinical Presentation and Long-Term Issues

Endometriosis may affect adolescent girls. The scientific literature on endometriosis in adolescents is limited, and many aspects are still uncertain despite a growing number of related reports. The prevalence of endometriosis in adolescents is unknown, but in selected groups of patients undergoing laparoscopy, it has been found to be higher than 50%. The physiopathology of adolescent endometriosis has not been specifically shown. However, the presence of a family history and associated genital malformations are more frequently identified in adolescents with endometriosis. The clinical presentation of the disease in adolescents has been assessed by numerous prospective and retrospective studies, and the risk factors for the development of endometriosis are well-known. The recommended diagnostic strategy is actually well-characterized, even if an early diagnosis is hardly ever made. The therapeutic management is also more consensual, but not definitive because of a lack of prospective studies evaluating either short- or long-term results and the impact on the natural history of the disease. Finally, the long-term sequelae are still a burden, and many questions are unanswered, despite new insights provided by a few recent reports evaluating the progression of the disease and its effects on subsequent fertility. Further studies are needed to better assess these issues.

Is the detection of endometrial nerve fibers useful in the diagnosis of endometriosis?

Laparoscopy is currently considered to be the gold standard investigation in patients suspected to have endometriosis, but this is an invasive and relatively costly procedure and there may be significant delays in diagnosis. As the eutopic endometrium is recognized to be abnormal in patients with endometriosis, it has been suggested that endometrial sampling could provide an indirect diagnostic approach. In particular, recent reports have suggested that the presence of nerve fibers within the endometrial functional layer could represent a specific and sensitive marker of concurrent peritoneal endometriosis. However, such studies have been performed in select patient groups and using novel sampling and analytic techniques that are not used routinely in clinical pathology laboratories. The present study was performed upon conventional endometrial biopsies from 68 patients who underwent laparoscopy for suspected endometriosis. The biopsies were stained immunohistochemically for the neural marker PGP 9.5 and examined in a blinded manner. Endometrial functional layer nerve fibers were identified in 15 (22%) biopsies overall including 9/47 (19%) cases with histologically confirmed peritoneal endometriosis and 6/21 (29% cases) without endometriosis. There was no correlation between the presence of functional layer nerve fibers and the presenting symptoms, endometrial histology, or current hormonal therapy. In our experience, endometrial functional layer nerve fibers assessment performed using standard immunohistochemical techniques on routine biopsy specimens proved neither sensitive nor specific for the diagnosis of endometriosis. Pathologists and gynecologists considering this diagnostic approach should carefully consider the methodological factors that may influence its reliability.

Oxidative cell injury as a predictor of endometriosis progression

BACKGROUND

There is increasing evidence that oxidative stress is one of the key factors for progression of endometriosis. In this prospective controlled trial, we measured 6 different biomarkers of oxidative stress targeting protein, lipid, and DNA to quantify the severity and progression of endometriosis and establish a diagnostic marker for the disease.

METHODS

A total of 62 consecutive patients were identified and enrolled in this study. After exclusion criteria, 44 patients were allocated to 3 groups: stage I/II (n = 14), stage III/IV (n = 16), and a control group (n = 14). The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-oxoguanine DNA glycosylase (OGG1), protein carbonyl (PC), lipid peroxidation (LPO), reactive oxygen species (ROS), and total antioxidant capacity (TAC) were accessed in peritoneal fluid and tissue.

RESULTS

Significantly higher levels of 8-OHdG and PC were seen in patients with endometriosis, in addition OGG1 expression was found to be significantly lower in patients with endometriosis (P < .001, P = .001, P = .033, respectively); ROS, TAC, and LPO were similar in stages I/II, stages III/IV, and control group. A predictive model was built using multivariable analyses and receiver-operating characteristics curves. The ability to predict and distinguish between patients without endometriosis, stage I/II endometriosis, and stage III/IV was very high. This model was highly discriminatory and had a concordance index of 0.87.

CONCLUSION

In this cohort, higher DNA damage and lower DNA repair activity was related to endometriosis progression. Our results indicate that oxidative stress as a biomarker of cell injury can be used as a reliable quantitative test of endometriosis severity.

Mapping histological levels of 8-hydroxy-2'-deoxyguanosine in female reproductive organs

Oxidative stress is associated with many disease states including gynecologic disease. This process can damage lipids, proteins and DNA. The present study highlights the role of oxidative stress induced DNA damage as measured by 8-hydroxy-2-deoxyguanosine in development of benign gynecological conditions (BGC). Our aim was to map the oxidative DNA damage on female reproductive organs and highlight the high amount found in a variety of benign gynecologic disorders. Seventeen biopsy specimens from female pelvic organs were divided in two groups: healthy organs tissue and BGC tissue. Healthy organs biopsy tissue included the cervix, tubes, uterus, peritoneum, and topic endometrium in secretory phase. Benign gynecological biopsy tissue included hydrosalpinges, leiomyoma, adenomyosis and tubal cysts. Immunohistochemical staining showed significantly higher levels of DNA damage between BGC and healthy organs [19.36 % (6.20; 32.51) vs. 4.61 % (0.63; 8.53); P < 0.0344]. Our results highlight the involvement of oxidative stress DNA damage in female benign pelvic disease. Hydrosalpinges, leiomyoma, and adenomyosis exhibit the highest amounts of oxidative DNA damage in the pelvic cavity.