Pathogenesis of endometriosis

The Known, the Unknown and the Future of the Pathophysiology of Endometriosis

Endometriosis is one of the most common causes of chronic pelvic pain and infertility, affecting 10% of women of reproductive age. A delay of up to 9 years is estimated between the onset of symptoms and the diagnosis of endometriosis. Endometriosis is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in research on endometriosis have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". There are several theories on the etiology of the disease, but the origin of endometriosis remains unclear. This review addresses the role of microRNAs (miRNAs), which are naturally occurring post-transcriptional regulatory molecules, in endometriotic lesion development, the inflammatory environment within the peritoneal cavity, including the role that cytokines play during the development of the disease, and how animal models have helped in our understanding of the pathology of this enigmatic disease.

Expression Profiles of Genes Related to Development and Progression of Endometriosis and Their Association with Paraben and Benzophenone Exposure

Increasing evidence has been published over recent years on the implication of endocrine-disrupting chemicals (EDCs), including parabens and benzophenones in the pathogenesis and pathophysiology of endometriosis. However, to the best of our knowledge, no study has been published on the ways in which exposure to EDCs might affect cell-signaling pathways related to endometriosis. We aimed to describe the endometriotic tissue expression profile of a panel of 23 genes related to crucial cell-signaling pathways for the development and progression of endometriosis (cell adhesion, invasion/migration, inflammation, angiogenesis, and cell proliferation/hormone stimulation) and explore its relationship with the exposure of patients to parabens (PBs) and benzophenones (BPs). This cross-sectional study included a subsample of 33 women with endometriosis from the EndEA study, measuring their endometriotic tissue expressions of 23 genes, while urinary concentrations of methyl-, ethyl-, propyl-, butyl-paraben, benzophenone-1, benzophenone-3, and 4-hydroxybenzophenone were determined in 22 women. Spearman's correlations test and linear and logistic regression analyses were performed. The expression of 52.2% of studied genes was observed in >75% of endometriotic tissue samples and the expression of 17.4% (n = 4) of them in 50-75%. Exposure to certain PB and BP congeners was positively associated with the expression of key genes for the development and proliferation of endometriosis. Genes related to the development and progression of endometriosis were expressed in most endometriotic tissue samples studied, suggesting that exposure of women to PBs and BPs may be associated with the altered expression profile of genes related to cellular pathways involved in the development of endometriosis.

Modulation of the Proliferative Pathway, Neuroinflammation and Pain in Endometriosis

Endometriosis is a chronic disease characterized by pelvic inflammation. This study aimed at investigating the molecular mechanisms underlying the pathology and how they can be modulated by the administration of a natural compound, Actaea racemosa (AR). We employed an in vivo model of endometriosis in which rats were intraperitoneally injected with uterine fragments from donor animals. During the experiment, rats were monitored by abdominal high-frequency ultrasound analysis. AR was able to reduce the lesion's size and histological morphology. From a molecular point of view, AR reduced hyperproliferation, as shown by Ki-67 and PCNA expression and MAPK phosphorylation. The impaired apoptosis pathway was also restored, as shown by the TUNEL assay and RT-PCR for Bax, Bcl-2, and Caspase levels. AR also has important antioxidant (reduced Nox expression, restored SOD activity and GSH levels, and reduced MPO activity and MDA levels) and anti-inflammatory (reduced cytokine levels) properties. Moreover, AR demonstrated its ability to reduce the pain-like behaviors associated with the pathology, the neuro-sensitizing mediators (c-FOS and NGF) expression, and the related central astrogliosis (GFAP expression in the spinal cord, brain cortex, and hippocampus). Overall, our data showed that AR was able to manage several pathways involved in endometriosis suppression.

The effects of Rituximab on experimental endometriosis model in rats

AIM

Endometriosis is a common, chronic benign gynecologic disease and distresses women in their reproductive age. Yet the pathogenesis of endometriosis is not clear, multifactorial mechanisms have been characterized for the initiation, progression, and regression of this disease. It has been suggested that immune cells in the lymphoid lineage play essential roles in accepting or rejecting the survival, implantation, and proliferation of endometrial and endometriotic cells and, dysfunction of B-lymphocytes (B-cells) are one of the major causes for the progression of endometriosis. In this study, we aimed to evaluate the potential therapeutic efficacy of Rituximab, an inhibitor for B-cells, for endometriosis in an experimental animal model.

METHODS

Experimental endometriosis animal model has been utilized using mature female rats. Rats underwent surgery to initiate endometriosis on the abdominal wall. After confirming for endometriosis, rats were treated with either Rituximab or saline solution. After 14 days of treatment, implants were dissected, and evaluated for volumes and histological features. Anti-CD-20 antibody was used for immunohistochemistry scoring purposes.

RESULTS

There is significant decrease in the volume of endometriotic implants after treatment with Rituximab (188.81 ± 149.42 vs 20.37 ± 13.08, p = 0.001). There are also significant differences for the B-cell count and fibrosis score between the control and treatment groups (3.08 ± 2.6 vs 1.56 ± 1.42., p = 0.043).

CONCLUSION

In an experimental rat endometriosis model, we assessed Rituximab, an antibody for B-lymphocyte, as a candidate medical treatment for endometriosis. Additional studies are required to further evaluate the effects of Rituximab on the prevention of endometriosis.

The Role of Dietary Fats in the Development and Treatment of Endometriosis

Endometriosis is an estrogen-dependent disease in women of childbearing age that affects approximately 5–15% of the female population. The etiology of endometriosis is complex, multifaceted, and not fully understood. In endometriosis, which is an estrogen-related chronic inflammatory condition, estrogen plays a major role in endometrial cellular growth. High estrogen levels could be another risk factor for developing endometriosis. The aim of this review is to update knowledge on the impact of dietary fats on the development of endometriosis and chronic inflammation in women with endometriosis and diet therapy. Dietary fat may be linked with the progression and development of endometriosis, but studies have been contradictory due to various issues including sample size, different study designs, and different methodological aspects. Results have shown that the risk of endometriosis may increase with a higher consumption of products rich in saturated fats, especially palmitic acid and trans-unsaturated fatty acids. Monounsaturated fats and omega-3 polyunsaturated fatty acids may likely be connected with a lower risk of developing endometriosis and with reductions in the severity of disease. Monounsaturated fats, omega-3 polyunsaturated fatty acids, and a suitable eicosapentaenoic acid to arachidonic acid ratio can be used in diet therapy to improve quality of life by reducing pain and inflammation. Further research is needed in order to fully understand the influence of dietary fats on the risk of development of this disease.

Altered Expression of Interleukin-18 System mRNA at the Level of Endometrial Myometrial Interface in Women with Adenomyosis

Adenomyosis is a uterine pathology characterized by a deep invasion of endometrial glands and stroma, disrupting the endometrial−myometrial interface (EMI). Interleukin-18 (IL-18) system is a dominant cytokine involved in the menstrual cycle of human endometrium. IL-18 may play a defensive role against maternal immune response in the uterine cavity. The present study was designed to determine IL-18-mediated immune response at the level of EMI. We uncovered that mRNA of IL-18 system, including IL-18, IL-18 receptor (IL-18R), and its antagonist, IL-18 binding protein (IL-18BP), expressed in eutopic, ectopic endometrium, and corresponding myometrium in patients with adenomyosis. IL-18 system was demonstrated in paired tissue samples by immunochemistry and immunofluorescence study. According to RT-PCR with CT value quantification and 2−∆∆Ct method, a significant down-regulation of IL-18BP in corresponding myometrium in comparison to eutopic endometrium (p < 0.05) indicates that the IL-18 system acts as a local immune modulator at the level of EMI and regulating cytokine networks in the pathogenesis of adenomyosis. Furthermore, an increased IL-18 antagonist to agonist ratio was noted in ectopic endometrium compared with corresponding myometrium. We suggest that altered IL-18 system expression contributes to immunological dysfunction and junctional zone disturbance in women with adenomyosis.

Food groups and nutrients consumption and risk of endometriosis: a systematic review and meta-analysis of observational studies

Dietary factors may play a role in the etiology of endometriosis and dietary intake of some food groups and nutrients could be associated with endometriosis risk. This systematic review and meta-analysis of observational studies was conducted to summarize the findings on the association between dietary intakes of selected food groups and nutrients (dairy, fats, fruits, vegetables, legumes, and animal-derived protein sources), and the risk of endometriosis among adult women. PubMed, Scopus, and ISI Web of Science were systematically searched up to September 2022. The inverse variance-weighted fixed-effect method was used to estimate the effect size and corresponding 95% CI. A total of 8 publications (4 studies) including 5 cohorts and 3 case-control with a sample size ranging from 156 to 116,607 were included in this study. A higher intake of total dairy [all low-fat and high-fat dairy foods] was associated with decreased risk of endometriosis (RR 0.90; 95% CI, 0.85 to 0.95; P < 0.001; I² = 37.0%), but these associations were not observed with intakes of low or high-fat dairy, cheese or milk. Increased risk of endometriosis was associated with higher consumption of red meat (RR 1.17; 95% CI, 1.08 to 1.26; P < 0.001; I² = 82.4%), trans fatty acids (TFA) (RR 1.12; 95% CI, 1.02 to 1.23; P = 0.019; I² = 73.0%), and saturated fatty acids (SFA) (RR 1.06; 95% CI, 1.04 to 1.09; P < 0.001; I² = 57.3%). The results of this meta-analysis suggest that there may be differing associations between dietary intake of dairy foods, red meat, SFAs, and TFAs and the risk of endometriosis. It may be useful to extend the analysis to other types of food groups and dietary patterns to obtain a complete picture. Additionally, further investigations are needed to clarify the role of diet in the incidence and progression of endometriosis.Trial registration: PROSPERO, CRD42020203939.

Role of AMPK/mTOR, mitochondria, and ROS in the pathogenesis of endometriosis

Endometriosis is the presence of endometrial tissue outside the uterine cavity usually in the ovaries, fallopian tube, and pelvic cavity. It's a chronic enigmatic gynecological condition associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, and oxidative stress. This environment promotes cell survival through the binding of membrane receptors and subsequent cascading activation of intracellular kinases that stimulate a cellular response. In endometriosis, well-established signaling pathways, mTOR and AMPK, are altered via steroid hormones and other factors to promote cell growth, migration, and proliferation. This is accompanied by dysfunction in the mitochondria that increase energy production to sustain proliferation demands consequently leading to reactive oxygen species overproduction. This review aims to summarize the role of altered mTOR/AMPK signaling pathway, mitochondrial dysfunction, and reactive oxygen species overproduction along with providing therapeutic and diagnostic approaches. Highlighting these factors would provide a better understanding to reach a coherent theory for the pathogenesis of endometriosis.

A Revised Stem Cell Theory for the Pathogenesis of Endometriosis

During the past decade, a stem cell-based hypothesis has emerged (among many others) to explain the pathogenesis of endometriosis. The initial hypothesis proposed that endometriosis arose from a single or a few specific cells with stem cell properties, including self-renewal and multi-lineage cell differentiation. The origins of the endometriosis-initiating stem cells were thought to be the bone marrow, uterine endometrium, and other tissues. Based on the implantation or metastatic theory in combination with the initial stem cell theory, one or a few multipotent stem/progenitor cells present in the eutopic endometrium or bone marrow translocate to ectopic sites via fallopian tubes during menstruation, vasculolymphatic routes, or through direct migration and invasion. Subsequently, they give rise to endometriotic lesions followed by differentiation into various cell components of endometriosis, including glandular and stromal cells. Recent somatic mutation analyses of deep infiltrating endometriosis, endometrioma, and eutopic normal endometrium using next-generation sequencing techniques have redefined the stem cell theory. It is now proposed that stem/progenitor cells of at least two different origins—epithelium and stroma—sequentially, differentially, but coordinately contribute to the genesis of endometriosis. The dual stem cell theory on how two (or more) stem/progenitor cells differentially and coordinately participate in the establishment of endometriotic lesions remains to be elucidated. Furthermore, the stem/progenitor cells involved in this theory also remain to be identified. Given that the origin of endometriosis is eutopic endometrium, the candidate cells for endometriotic epithelium-initiating cells are likely to be endometrial epithelial cells positive for either N-cadherin or SSEA-1 or both. The candidate cells for endometriotic stroma-initiating cells may be endometrial mesenchymal stem cells positive for SUSD2. Endometrial side population cells are also a possible candidate because they contain unipotent or multipotent cells capable of behaving as endometrial epithelial and stromal stem/progenitor cells.

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.

Differences in growth and vascularization of ectopic menstrual and non-menstrual endometrial tissue in mouse models of endometriosis

STUDY QUESTION

Is there a difference in the growth and vascularization between murine endometriotic lesions originating from menstrual or non-menstrual endometrial fragments?

SUMMARY ANSWER

Endometriotic lesions developing from menstrual and non-menstrual tissue fragments share many similarities, but also exhibit distinct differences in growth and vascularization, particularly under exogenous estrogen stimulation.

WHAT IS KNOWN ALREADY

Mouse models are increasingly used in endometriosis research. For this purpose, menstrual or non-menstrual endometrial fragments serve for the induction of endometriotic lesions. So far, these two fragment types have never been directly compared under identical experimental conditions.

STUDY DESIGN, SIZE, DURATION

This was a prospective experimental study in a murine peritoneal and dorsal skinfold chamber model of endometriosis. Endometrial tissue fragments from menstruated (n = 15) and non-menstruated (n = 21) C57BL/6 mice were simultaneously transplanted into the peritoneal cavity or dorsal skinfold chamber of non-ovariectomized (non-ovx, n = 17), ovariectomized (ovx, n = 17) and ovariectomized, estrogen-substituted (ovx+E2, n = 17) recipient animals and analyzed throughout an observation period of 28 and 14 days, respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The engraftment, growth and vascularization of the newly developing endometriotic lesions were analyzed by means of high-resolution ultrasound imaging, intravital fluorescence microscopy, histology and immunohistochemistry.

MAIN RESULTS AND THE ROLE OF CHANCE

Menstrual and non-menstrual tissue fragments developed into peritoneal endometriotic lesions without differences in growth, microvessel density and cell proliferation in non-ovx mice. Lesion formation out of both fragment types was markedly suppressed in ovx mice. In case of non-menstrual tissue fragments, this effect could be reversed by estrogen supplementation. In contrast, endometriotic lesions originating from menstrual tissue fragments exhibited a significantly smaller volume in ovx+E2 mice, which may be due to a reduced hormone sensitivity. Moreover, menstrual tissue fragments showed a delayed vascularization and a reduced blood perfusion after transplantation into dorsal skinfold chambers when compared to non-menstrual tissue fragments, indicating different vascularization modes of the two fragment types. To limit the role of chance, the experiments were conducted under standardized laboratory conditions. Statistical significance was accepted for a value of P < 0.05.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Endometriotic lesions were induced by syngeneic tissue transplantation into recipient mice without the use of pathological endometriotic tissue of human nature. Therefore, the results obtained in this study may not fully relate to human patients with endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

The present study significantly contributes to the characterization of common murine endometriosis models. These models represent important tools for studies focusing on the basic mechanisms of endometriosis and the development of novel therapeutic strategies for the treatment of this frequent gynecological disease. The presented findings indicate that the combination of different experimental models and approaches may be the most appropriate strategy to study the pathophysiology and drug sensitivity of a complex disease such as endometriosis under preclinical conditions.

STUDY FUNDING/COMPETING INTEREST(S)

There was no specific funding of this study. The authors have no conflicts of interest to declare.

Hidrox® and Endometriosis: Biochemical Evaluation of Oxidative Stress and Pain

Endometriosis is a gynecological and painful condition affecting women of reproductive age. It is characterized by dysfunctional endometrium-like implants outside of the uterine cavity. The purpose of this study was to evaluate the effects of Hidrox®, an aqueous extract of olive pulp containing hydroxytyrosol, on endometriotic lesions associated with pro-oxidative alterations and pain-like behaviors. Endometriosis was induced by intraperitoneal injection of uterine fragments, and Hidrox® was administered daily. At the end of the 14-day treatment, behavioral alterations were assessed and hippocampal tissues were collected. Laparotomy was performed, and the endometrial implants were harvested for histological and biochemical analysis. Hidrox® treatment reduced endometriotic implant area, diameter and volumes. Vehicle-treated rats showed lesional fibrosis, epithelial-mesenchymal transition and fibroblast-myofibroblast transdifferentiation, angiogenesis and pro-oxidative alterations in the peritoneal cavity. Hidrox® treatment reduced the aniline blue-stained area, α-smooth muscle actin (α-sma) and CD34 positive expressions. Moreover, it reduced mast cell recruitment into the lesions, myeloperoxidase activity and lipid peroxidation and increased superoxide dismutase (SOD) activity and glutathione levels in the endometrial explants. In the peritoneal fluid, Hidrox® treatment reduced interleukin (IL)-1β, IL2, IL6, tumor necrosis factor-α (TNF-α) and vascular endothelial grow factor (VEGF) levels increased by the disease. Hidrox® administration also reduced peripheral and visceral sensibility as shown by the behavioral tests (open field test, hot plate test, elevated plus maze test and acetic-acid-induced abdominal contractions). Animals treated with Hidrox® also showed reduced blood-brain barrier permeability and mast cell infiltration in the hippocampus, as well as astrocyte and microglia activation and brain oxidative status restoring brain-derived neurotrophic factor (BDNF) protein expression and increasing Nuclear factor erythroid 2-related factor 2 (Nfr2) nuclear translocation. In conclusion, Hidrox® displayed potential ameliorative effects on endometriotic implants and related pain-induced behaviors due to its potent antioxidative properties.

Inflammation to Infertility: Panoramic View on Endometriosis

Endometriosis is a disease caused by the implantation of endometrial glands and stroma outside the uterine cavity. It affects 10% of the reproductive-age women this means that 190 million women are affected worldwide. The definitive diagnosis requires surgical exploration or a laparoscopy which is of a high expense. The pathogenesis of the disease is heterogeneous and poorly understood despite the progress in the research field. Infertility is one of the main symptoms of Endometriosis. The mechanism behind this remains unclear. Literature suggests that Endometriosis reduces implantation capacity, increases the risk of pregnancy loss, and causes anatomical obstruction imposed by endometriotic lesions. The disease has a high burden to it by decreasing the quality of women's life and imposing negative consequences for their productivity, social life, and emotional wellbeing. Since inflammation is considered the hallmark of endometriosis, it is worth looking at the mechanism of how inflammation is linked to infertility in endometriosis patients. In this study, we summarized the recent finding of how inflammation can affect oocyte, endometrium, hormones, and sperm.

Adenosine-5'-triphosphate suppresses proliferation and migration capacity of human endometrial stem cells

Extracellular ATP through the activation of the P2X and P2Y purinergic receptors affects the migration, proliferation and differentiation of many types of cells, including stem cells. High plasticity, low immunogenicity and immunomodulation ability of mesenchymal stem cells derived from human endometrium (eMSCs) allow them to be considered a prominent tool for regenerative medicine. Here, we examined the role of ATP in the proliferation and migration of human eMSCs. Using a wound healing assay, we showed that ATP-induced activation of purinergic receptors suppressed the migration ability of eMSCs. We found the expression of one of the ATP receptors, the P2X₇ receptor in eMSCs. In spite of this, cell activation with specific P2X₇ receptor agonist, BzATP did not significantly affect the cell migration. The allosteric P2X₇ receptor inhibitor, AZ10606120 also did not prevent ATP-induced inhibition of cell migration, confirming that inhibition occurs without P2X₇ receptor involvement. Flow cytometry analysis showed that high concentrations of ATP did not have a cytotoxic effect on eMSCs. At the same time, ATP induced the cell cycle arrest, suppressed the proliferative and migration capacity of eMSCs and therefore could affect the regenerative potential of these cells.

Endometriosis of the Urinary Bladder Causing a Right Hydronephrosis: A Case Report

BACKGROUND Endometriosis is a chronic and benign condition in which endometrial glands and stroma are present outside the uterine cavity. The pathogenesis of endometriosis is not fully understood; however, several mechanisms have been hypothesized. Endometriosis is a common clinical presentation in gynecology, but affecting the urinary tract is a rare phenomenon, occurring in 0.3-12% of cases. In more severe forms, the initial presentation may be hydronephrosis or infertility. CASE REPORT We describe the case of a 25-year-old Saudi woman who presented with obstructive urinary tract symptoms and was diagnosed with urinary bladder endometriosis complicated with a right hydronephrosis. After thorough investigations and workups, the management was taken on by a multidisciplinary team approach. CONCLUSIONS This case report shows that hormonal therapy management resulted in a satisfactory outcome contrary to the surgical resection approach that is discussed in many articles.

A prospective cohort study of meat and fish consumption and endometriosis risk

BACKGROUND

Only 2 case-control studies have examined the associations between consumption of meat products and endometriosis risk with inconsistent results. Consumption of animal products has the potential to influence endometriosis risk through effects on steroid hormones levels.

OBJECTIVE

We sought to determine whether higher intake of red meat, poultry, fish, and seafood are associated with risk of laparoscopically confirmed endometriosis.

STUDY DESIGN

A total of 81,908 participants of the prospective Nurses' Health Study II were followed up from 1991 through 2013. Diet was assessed via food frequency questionnaire every 4 years. Cox proportional hazards models were used to calculate rate ratios and 95% confidence intervals.

RESULTS

During 1,019,294 person-years of follow-up, 3800 cases of incident laparoscopically confirmed endometriosis were reported. Women consuming >2 servings/d of red meat had a 56% higher risk of endometriosis (95% confidence interval, 1.22-1.99; P_trend < .0001) compared to those consuming ≤1 serving/wk. This association was strongest for nonprocessed red meats (rate ratio, 1.57; 95% confidence interval, 1.35-1.83 for ≥2 servings/d vs ≤1 servings/wk; P_trend < .0001), particularly among women who had not reported infertility (P_interaction = .0004). Women in the highest category of processed red meat intake also had a higher risk of endometriosis (rate ratio, 1.20; 95% confidence interval, 1.06-1.37 for ≥5 servings/wk vs <1 serving/mo; P_trend = .02). Intakes of poultry, fish, shellfish, and eggs were unrelated to endometriosis risk.

CONCLUSION

Our prospective analysis among premenopausal US nurses suggests that red meat consumption may be an important modifiable risk factor for endometriosis, particularly among women with endometriosis who had not reported infertility and thus were more likely to present with pain symptoms. Well-designed dietary intervention studies among women with endometriosis could help confirm this observation.

Appendectomy Scar Endometriosis: A Case Report

Scar endometriosis is one of the rare cases of surgery, which specifically occurs in gynecological surgeries. It is important to do a correct diagnosis in such rare cases to have an efficient treatment. The disease is commonly observed in child-bearing women with clinical manifestations such as acute abdomen or chronic and cyclic pelvic pain. Herein we reported a case of appendectomy scar endometriosis.

Endométriome ombilical: à propos d’un cas et revue de la littérature

L’endométriose se définit comme l’implantation de tissu endométrial en dehors de la cavité utérine. Elle touche environ 10% des femmes en âge de procréer. La localisation ombilicale est rare et la physiopathologie mal connue. Nous rapportons le cas d’une patiente de 42 ans, nulligeste, aux antécédents de myomectomie 5 ans auparavant, qui présentait une douleur cyclique avec une masse ombilicale dont le diagnostic était en faveur d’un endométriome ombilical, confirmée par l’étude histologique de la pièce de biopsie de la masse. Le traitement a consisté à une exérèse large de la masse associée à une exploration du pelvis et une plastie ombilicale.

Retroperitoneal Endometriotic Cyst Infiltrated in the Iliopsoas Incidentally Found in a Patient with Acute Back Pain

We describe a rare case of retroperitoneal endometriotic cyst infiltrated in the iliopsoas incidentally found in a patient with acute back pain. Endometriosis at the pelvic peritoneum, including the Douglas pouch, has been reported often; there are few reports of cystic endometriosis in the retroperitoneal cavity. Today there are various theories regarding how endometriosis occurs. By pathological findings and lesion sites of the present case, we concluded that the endometrial tissues in the menstrual blood might metastasize lymphatically and implant and form the retroperitoneal cyst.

p27kip1 as a key regulator of endometriosis

p27^kip1 as a key regulator of endometriosis Gonçalves GA p27^kip1 is a cyclin-dependent kinase (CDK) inhibitor whose specific late G1 destruction allows progression of the cell across the G1/S boundary. There is a direct relationship between low level of p27 and rapid proliferation occurring in several benign states and in many malignances. In the glandular cells of the normal endometrium, the level of p27^kip1 is exceedingly low during the proliferative phase, whereas it is markedly increased during the secretory phase. The expression of p27^kip1 in endometriosis is very low but has been found to increase following treatment with progesterone. However, estrogen exposure is considered as a major risk factor in developing endometrial cancer. Endometriosis endometrial cells cultures have also lower levels of p27^kip1 compared to heath endometrial cells cultures and restore the cell cycle balance when transduced with an adenoviral vector carring the p27^kip1 coding gene (Adp27EGFP). More uniform and rigorous studies are required to confirm these and additional markers utility in a diagnostic and possible treatment panel. As a major clinical priority is to determine which lesions can be treated medically and which require surgical intervention, focusing future studies on markers that distinguish response to hormone therapy or are involved in hormone regulation, will be important future considerations. The goal of this highlight review is to provide a broad overview of the advancements in studies about endometriosis mainly correlating the cytokine p27^kip1 expression with the diagnostic and disease treatment.

Vitamin C is effective for the prevention and regression of endometriotic implants in an experimentally induced rat model of endometriosis

OBJECTIVE

Endometriosis is a chronic inflammatory disease pathologically defined as the presence of endometrial-like tissue outside the uterine cavity. It is one of the most important diseases affecting women of reproductive age. The process of endometriotic implant growth is mediated by many complex interactions of immunologic, hormonal, genetic, and environmental mediators. Vitamin C (ascorbic acid), besides playing a role in preventing invasion and metastasis, is an antioxidant having anti-inflammatory and -angiogenic effects. In this study, we aimed to investigate the effect of vitamin C on the prevention and regression of endometriotic implants in a rat model of endometriosis.

MATERIALS AND METHODS

This was a prospective, comparative, experimental animal study. After endometriotic implants were induced simultaneously, rats were divided into three groups. Group A was given 500 mg/kg of intravenous vitamin C every 2 days, starting immediately after implantation (n = 11). All rats had a second operation 21 days after the initial one and had the lesion volumes measured. Group B was given 500 mg/kg of intravenous vitamin C every 2 days, starting 21 days after this operation (n = 11). All rats were sacrificed 21 days after the third operation. Implant volume, weight measurements, and histopathological evaluation of the lesions were carried out. Group A received vitamin C throughout the study, while Group C (n = 11) was not given any medication. The findings in the three groups were compared.

RESULTS

At the second laparotomy after the induction, Group A had the smallest implant volume with a statistically significant difference compared to Group B (p = 0.012). The end-of-study volumes of endometriotic implants of group B were significantly smaller than the first volumes (p < 0.05).

CONCLUSION

Intravenous vitamin C treatment might have a suppressive effect on the prevention of endometriotic implant induction and regression of endometriotic implant volumes.

Immunohistochemical Expression of p53, MDM2, and p21Wafi Oncoproteins in Endometriomas But Not Adenomyosis

OBJECTIVE

p53, MDM2, and p21Waf1 are oncoproteins that regulate the cell cycle. The purpose of this study was to examine the distribution of p53, MDM2, and p21Waf1 oncoprotein expression in endometriomas and in adenomyosis.

METHODS

Tissue samples from 25 women with pathologically confirmed endometriomas and 31 women with pathologically confirmed adenomyosis were analyzed. Expression of p53, MDM2, and p21Waf1 oncoproteins was assessed by immunohistochemical nuclear staining.

RESULTS

p53, MDM2, and p21Waf1 expression were detected in 20%, 60%, and 80% of endometrioma tissue samples, respectively. All endometrioma tissue samples expressing p53 also tested positive for both MDM2 and p21Waf1. MDM2 expression was significantly higher in the proliferative than in the secretory phase of the cycle. In contrast, all 31 adenomyosis tissue samples were negative for p53, MDM2, and p21Waf1 expression.

CONCLUSION

The expression of p53, MDM2, and p21Waf1 suggests a role for these oncoproteins in the regulation of endometrioma cell growth, but not in adenomyosis.

DNA methylation in endometriosis (Review)

Endometriosis is defined by the presence and growth of functional endometrial tissue, outside the uterine cavity, primarily in the ovaries, pelvic peritoneum and rectovaginal septum. Although it is a benign disease, it presents with malignant characteristics, such as invasion to surrounding tissues, metastasis to distant locations and recurrence following treatment. Accumulating evidence suggests that various epigenetic aberrations may play an essential role in the pathogenesis of endometriosis. Aberrant DNA methylation represents a possible mechanism repsonsible for this disease, linking gene expression alterations observed in endometriosis with hormonal and environmental factors. Several lines of evidence indicate that endometriosis may partially be due to selective epigenetic deregulations influenced by extrinsic factors. Previous studies have shed light into the epigenetic component of endometriosis, reporting variations in the epigenetic patterns of genes known to be involved in the aberrant hormonal, immunologic and inflammatory status of endometriosis. Although recent studies, utilizing advanced molecular techniques, have allowed us to further elucidate the possible association of DNA methylation with altered gene expression, whether these molecular changes represent the cause or merely the consequence of the disease is a question which remains to be answered. This review provides an overview of the current literature on the role of DNA methylation in the pathophysiology and malignant evolution of endometriosis. We also provide insight into the mechanisms through which DNA methylation-modifying agents may be the next step in the research of the pharmaceutical treatment of endometriosis.

in vitro Anti-Proliferative Effect of Adiponectin on Human Endometriotic Stromal Cells through AdipoR1 and AdipoR2 Gene Receptor Expression

BACKGROUND

Endometriosis is a complex disorder in reproductive age women which consist of stromal and epithelial cells implantation outside the uterine cavity. Adiponectin is a member of cytokine family with various metabolic roles and proliferation inhibition of many cancer cells. The aim of the present research was to determine adiponectin effect on human endometriotic stromal cells (ESCs) proliferation and their expression of adiponectin receptors.

METHODS

In this experimental study, endometrial biopsies (n=7) were taken. ESCs isolation was done by enzymatic digestion and cell filtrations. ESCs of each biopsy were divided into four groups: 0 (control), 10, 100, and 200 ng/ml adiponectin concentrations in three different times (24, 48 or 72 h). The effect of adiponectin on ESC viability and expression of mRNA Adipo receptor1 (R1) and Adipo receptor2 (R2) was determined by Trypan blue staining and semi-quantitative RT-PCR, respectively. Data were analyzed by one-way ANOVA and unpaired student's t-test, and P<0.05 was considered statistically significant.

RESULTS

Adiponectin inhibited human endometriotic stromal cell proliferation in time- and dose-dependent manners significantly (P=0.001). Expression of AdipoR1 and AdipoR2 gene receptors was increased in human ESCs significantly (P<0.05).

CONCLUSIONS

Adiponectin can suppress endometriosis by inhibiting ESC proliferation and increased AdipoR1 and AdipoR2 expression.

[Clear cell adenocarcinoma arising from abdominal wall endometriosis]

BACKGROUND

Clear cell carcinoma originating in the abdominal wall is a rare event. It is generally associated with endometrial tissue implants left behind after a caesarean section or other gynaecological operations. Its pathophysiology is complex and controversial.

CLINICAL CASE

The case is presented of a 45 year-old female with history of three caesarean sections, who was seen due to having a tumour mass of 6 months onset in the anterior abdominal wall. Imaging studies confirmed its location, and due to measuring 9 by 7 cm it was suspected to be an urachal tumour. A resection with wide margins was performed. The histopathology report was of a clear cell adenocarcinoma originated in ectopic endometrial tissue, with negative margins.

CONCLUSION

This is a very rare case, with few cases reported in the literature. This diagnosis should be included in tumours of the abdominal wall.

Development of a subcutaneous endometriosis rat model

PURPOSE

To present a rat model of subcutaneous endometriosis for the study of pathophysiology and the effects of drugs.

METHODS

Fifty three-month-old female Wistar rats (Rattus norvergicus) were distributed into one control group and four treatment groups: estradiol (2.5; 5; 10 mg/kg s.c.), medroxyprogesterone acetate (0.5; 2; 5 mg/kg s.c.), triptorelin pamoate (0.18; 0.56 mg/kg s.c.) and acetylsalicylic acid (3 mg/kg per os). The animals were autoimplanted subcutaneously with 4x4-mm uterine fragments to induce endometriosis. The endometriomas were measured on days 1, 7, 14 and 21. The relative dry and wet weights of the endometrioma were used to evaluate response to the drug. Endometrial-like tissue was confirmed by histology. The greatest weight gain was observed on day 14 (relative wet weight: 29.1 ± 6.7 mg%, relative dry weight: 5.3 ± 0.9 mg %). Treatments were administered between day 5 and day 14.

RESULTS

The relative wet weight of the hemiuterus in the 10 mg/kg estradiol group differed significantly from control and the other two estradiol groups (p=0.0001). In the medroxyprogesterone acetate group the weight decreased significantly but this decrease was not dose-dependent. Weight reduction was also significant in the triptorelin pamoate and the acetylsalicylic acid groups.

CONCLUSION

The model of subcutaneous endometriosis is reproducible, low-cost and easy to perform, and suitable for the study of pathophysiology and the effects of drugs.

A potential novel treatment strategy: inhibition of angiogenesis and inflammation by resveratrol for regression of endometriosis in an experimental rat model

The aim of our study was to evaluate the effectiveness of resveratrol in experimentally induced endometrial implants in rats through inhibiting angiogenesis and inflammation. Endometrial implants were surgically induced in 24 female Wistar-Albino rats in the first surgery. After confirmation of endometriotic foci in the second surgery, the rats were divided into resveratrol (seven rats), leuprolide acetate (eight rats), and control (seven rats) groups and medicated for 21 d. In the third surgery, the measurements of mean areas and histopathological analysis of endometriotic lesions, VEGF, and MCP-1 measurements in blood and peritoneal fluid samples, and immunohistochemical staining were evaluated. After treatment, significant reductions in mean areas of implants (p < 0.01) and decreased mean histopathological scores of the implants (p < 0.05), mean VEGF-staining scores of endometriotic implants (p = 0.01), and peritoneal fluid levels of VEGF and MCP-1 (p < 0.01, for VEGF and p < 0.01, for MCP-1) were found in the resveratrol and leuprolide acetate groups. Serum VEGF (p = 0.05) and MCP-1 (p = 0.01) levels after treatment were also significantly lower in the resveratrol and leuprolide acetate groups. Resveratrol appears to be a potential novel therapeutic agent in the treatment of endometriosis through inhibiting angiogenesis and inflammation. Further studies are needed to determine the optimum effective dose in humans and to evaluate other effects on reproductive physiology.

Human chorionic gonadotropin improves endometriosis through downregulation of leptin expression in rats

OBJECTIVE

To investigate whether and how human chorionic gonadotropin (HCG) treatment ameliorates endometriosis in an endometriotic rat model.

METHODS

Twenty-four endometriosis rats were established and were randomly divided into four groups, and then the rats were treated with 19.4, 25.8, and 51.6 IU/100 g weight/day of HCG, respectively. The control group was treated with 0.9% NaCl. After 15 days (3 estrous cycles), the ectopic lesion volume and the expression of leptin protein in eutopic and ectopic endometrium were investigated.

RESULTS

After HCG treatment, the volumes of endometriotic lesions were significantly smaller than those before treatment. During endometriosis development, the expression of leptin protein in eutopic and ectopic endometrium was remarkably increased. HCG administration reversed leptin upregulation in endometriotic tissues.

CONCLUSION

HCG therapy appears to be an effective treatment for endometriosis in rats through down-regulation of leptin expression in eutopic and ectopic endometrium.

mRNA-binding protein TIA-1 reduces cytokine expression in human endometrial stromal cells and is down-regulated in ectopic endometrium

BACKGROUND

Cytokines and growth factors play important roles in endometrial function and the pathogenesis of endometriosis. mRNAs encoding cytokines and growth factors undergo rapid turnover; primarily mediated by adenosine- and uridine-rich elements (AREs) located in their 3'-untranslated regions. T-cell intracellular antigen (TIA-1), an mRNA-binding protein, binds to AREs in target transcripts, leading to decreased gene expression.

OBJECTIVE

The purpose of this article was to determine whether TIA-1 plays a role in the regulation of endometrial cytokine and growth factor expression during the normal menstrual cycle and whether TIA-1 expression is altered in women with endometriosis.

METHODS

Eutopic endometrial tissue obtained from women without endometriosis (n = 30) and eutopic and ectopic endometrial tissues from women with endometriosis (n = 17) were immunostained for TIA-1. Staining intensities were evaluated by histological scores (HSCOREs). The regulation of endometrial TIA-1 expression by immune factors and steroid hormones was studied by treating primary cultured human endometrial stromal cells (HESCs) with vehicle, lipopolysaccharide, TNF-α, IL-6, estradiol, or progesterone, followed by protein blot analyses. HESCs were engineered to over- or underexpress TIA-1 to test whether TIA-1 regulates IL-6 or TNF-α expression in these cells.

RESULTS

We found that TIA-1 is expressed in endometrial stromal and glandular cells throughout the menstrual cycle and that this expression is significantly higher in the perimenstrual phase. In women with endometriosis, TIA-1 expression in eutopic and ectopic endometrium was reduced compared with TIA-1 expression in eutopic endometrium of unaffected control women. Lipopolysaccharide and TNF-α increased TIA-1 expression in HESCs in vitro, whereas IL-6 or steroid hormones had no effect. In HESCs, down-regulation of TIA-1 resulted in elevated IL-6 and TNF-α expression, whereas TIA-1 overexpression resulted in decreased IL-6 and TNF-α expression.

CONCLUSIONS

Endometrial TIA-1 is regulated throughout the menstrual cycle, TIA-1 modulates the expression of immune factors in endometrial cells, and downregulation of TIA-1 may contribute to the pathogenesis of endometriosis.

Is montelukast effective in regression of endometrial implants in an experimentally induced endometriosis model in rats?

OBJECTIVE

Montelukast, a selective antagonist of Type 1 cysteinyl leukotriene receptors (CysLT1Rs), antagonizes the proinflammatory and proasthmatic activities of CysLT1Rs. We investigated the effect of montelukast on a surgically induced endometriosis rat model.

STUDY DESIGN

Thirty-two sexually mature, cycling, female Wistar-Albino rats, in which endometriotic implants were surgically induced, were randomly divided into three groups. Group I [Montelukast (M), 10 rats)] was given 1.6 mg/kg/day of oral montelukast sodium. Group II [Leuprolide acetate (L), 11 rats] was given 1 mg/kg single dose of s.c.leuprolide acetate. Group III [Control (C), 11 rats] received saline solution through an orogastric tube and served as controls. After a 3-weeks medication, the rats were sacrificed to investigate the endometriotic implants for size and morphological and histological characteristics, including immunoreactivity of MMP-2 and VEGF.

RESULTS

The mean area of implants decreased from 48.2 ± 24.7 to 29.3 ± 15.8mm(2) in Group I (M) (P = 0.008) and from 62 ± 32.1 to 39.9 ± 18.1mm(2) in Group II (L) (P=0.003). In Group III (C), the mean area increased from 41.1 ± 31.1 to 60.4 ± 37.1mm(2) (P = 0.025). Histopathological analysis showed statistically significant lower scores in rats treated with montelukast compared to leuprolide and controls. MMP H scores were not different between the groups in both epithelial and stromal MMP-2 immunostaining. VEGF H scores were statistically lower in Group 1 (M) in epithelial VEGF immunostaining when compared to Group II (L) and Group III (C) (P=0.006).

CONCLUSION(S)

Montelukast may effectively cause a significant decrease in the area of endometriotic implants.

Endometriosis of the appendix

Purpose

Endometriosis is defined as functioning endometrial tissue outside of the uterus. Endometriosis of the appendix is uncommon. Its clinical presentation varies from asymptomatic to acute abdominal pain. The aims of this study were to describe our experience of managing patients with appendiceal endometriosis and to review the clinical characteristics of this medical condition.

Methods

Five cases of appendiceal endometriosis diagnosed between January 2007 and December 2012 were retrospectively reviewed. Patients treated for intra-abdominal endometriosis were excluded.

Results

The mean age at diagnosis was 33.8 years old. One patient was in the second trimester of pregnancy. Two patients were asymptomatic. Three patients had clinical symptoms including two with acute pain in the right lower quadrant and one with abdominal discomfort. Four patients showed appendiceal abnormalities in imaging studies including two cases of suspected mucocele and two cases of appendiceal infection. There were no suspicions of endometriosis of the appendix based on preoperative imaging studies. Three patients underwent appendectomy due to clinical symptoms, and two underwent incidental appendectomy combined with another operation. None of the patients received adjuvant therapy.

Conclusion

Appendiceal endometriosis should be included in the differential diagnosis for acute abdominal pain, especially when women of childbearing age present with clinical symptoms of acute appendicitis.

Isolation and identification of epithelial and stromal stem cells from eutopic endometrium of women with endometriosis

OBJECTIVE

The recent characterization of possible stem/progenitor cells in the endometrium has shed new light on the origins of ectopic endometrial tissue and the mechanism for the pathogenesis of endometriosis, but has raised new questions. Is it possible that abnormal endometrial stem/progenitor cells increase their capacity to implant and establish themselves as ectopic tissue, or that normal stem cells implant in abnormal peritoneum? This study investigated key stem cell properties in cologenic epithelial and stromal cells obtained from eutopic endometrium of women with endometriosis.

STUDY DESIGN

Single cell suspensions of endometrial epithelial and stromal cells were cultured at densities of 20, 50, 100 and 200cells/cm(2). Cloning efficiency (CE) was determined, and stem cell phenotypic surface markers were detected using Western blotting and quantitative real-time polymerase chain reaction.

RESULTS

CE was significantly higher in cells cultured at a density of 50cells/cm(2) compared with the other groups. After 15 days of culture, small and large colonies were observed. Large-colony-derived epithelial and stromal cells had high proliferative potentials, producing millions of cells in vitro, with strong expression of epithelial and stromal stem cell phenotypic surface markers EMA, CK, CD49f, THY-1(CD90), collagen type I, 5B5 and vimentin.

CONCLUSION

Adult stem cells were found in eutopic endometrium of women with endometriosis, and this may play an important role in disease development.

Theories on the pathogenesis of endometriosis

Endometriosis is a common, chronic inflammatory disease defined by the presence of extrauterine endometrial tissue. The aetiology of endometriosis is complex and multifactorial, where several not fully confirmed theories describe its pathogenesis. This review examines existing theories on the initiation and propagation of different types of endometriotic lesions, as well as critically appraises the myriad of biologically relevant evidence that support or oppose each of the proposed theories. The current literature suggests that stem cells, dysfunctional immune response, genetic predisposition, and aberrant peritoneal environment may all be involved in the establishment and propagation of endometriotic lesions. An orchestrated scientific and clinical effort is needed to consider all factors involved in the pathogenesis of this multifaceted disease and to propose novel therapeutic targets to reach effective treatments for this distressing condition.

Transtubal spread of endometrial carcinoma: correlation of intra-luminal tumour cells with tumour grade, peritoneal fluid cytology, and extra-uterine metastasis

AIMS

To assess the significance of intra-luminal tumour cells (ILTC) within the fallopian tubes of patients with endometrial carcinoma, with emphasis on high grade histological subtypes.

METHODS

Complete histological examination of fallopian tube tissue was performed in 36 low grade endometrioid adenocarcinomas and in a consecutive series of 226 high grade endometrial malignancies including 92 serous carcinomas, 64 grade 3 endometrioid carcinomas, 26 carcinosarcomas, 25 undifferentiated/dedifferentiated carcinomas, and 19 clear cell carcinomas. The presence of ILTC was correlated with peritoneal fluid cytology, histologically confirmed peritoneal tumour spread, and lymph node metastases.

RESULTS

ILTC were identified in 26% and 3% of high and low grade carcinomas, respectively. The presence of ILTC correlated strongly with positive peritoneal fluid cytology and with peritoneal metastasis in high grade tumours (both p < 0.001), and there was also a correlation with lymph node metastasis (p = 0.049). ILTC were more common in serous and undifferentiated carcinomas (>30%) but the differences between the high grade tumour subtypes were not statistically significant.

CONCLUSIONS

These findings suggest that ILTC associated with high grade endometrial cancers have the capacity to implant and invade the peritoneal cavity. Positive cytology in such cases may be more significant than in low grade tumours. Complete tubal examination may provide additional prognostic information in high grade endometrial carcinoma.

Soluble c-Met expression in the peritoneal fluid and serum of patients with different stages of endometriosis

INTRODUCTION

Hepatocyte growth factor (HGF), also known as scatter factor, and its receptor c-Met have been shown to be implicated in endometriosis. HGF acts as a mitogen, motogen, and morphogen on endometrial epithelial cells. The expression of c-Met on human endometrial cells has been reported. Many proteins are proteolytically released from the surface by a process known as ectodomain shedding. The aim of this study was to determine the levels of soluble c-Met (s-cMet) in the peritoneal fluid (PF) and serum samples of patients with different stages of endometriosis.

MATERIAL AND METHODS

39 PF and serum samples from normal healthy and 130 samples from different stages of patients with endometriosis (33 cases of stage I, 38 stage II, 30 stage III and 29 stage IV) were included in this study. Total protein concentration (TPC) and the level of s-cMet in the PF and serum were determined by Bio-Rad protein assay based on the Bradford dye procedure and enzyme-linked immunosorbent assay, respectively.

RESULTS

No significant change in the TPC was seen in the serum and PF of patients with endometriosis when compared with normal controls. Results obtained demonstrated that all PF and serum samples presented s-cMet expression, whereas, starting from stages I to IV endometriosis, a significant increase of s-cMet expression was observed as compared to controls.

CONCLUSION

The results of this study show that a high expression of s-cMet is correlated with advanced stages of endometriosis. It is also concluded that the detection of serum and PF s-cMet may be useful in classifying endometriosis.

[Endometriosis: the gynecologist's opinion]

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity. Endometriosis affects 7-10% of women of reproductive age, 60% of women with pelvic pain, and up to 50% of women with infertility. Etiology and pathogenesis of the disease are still unclear, with the theory of retrograde menstruation, and possibly associated cofactors, as the most important. The definitive method to diagnose endometriosis is visualization at surgery, preferably at laparoscopy, with histology confirmation of disease. The revised classification of the American Society for Reproductive Medicine is used to stage the disease and determine the patient's prognosis. The treatment of the disease depends on the patient's age, associated symptoms, and disease stage. Medical or surgical therapy may be used in case of pain associated with endometriosis, whereas surgery is the mainstay of treatment in case of endometriosis-associated infertility.

Abdominal scar endometriosis

Abdominal scar endometriosis is very rare. We report a case of abdominal scar endometriosis in a 32-year-old woman presented with a blue lesion over the abdominal scar for 7 months. She had history of intermittent dull aching pain over the scar for 5 years. Excision of the lump was done with the clinical diagnosis of vascular malformation over the scar. The specimen was sent for histopathological examination. The histopathological report revealed decidual change in the scar tissue suggesting abdominal scar endometriosis. Abdominal scar endometriosis should be kept in mind while dealing a case of the painful lump over the abdominal scar in any woman of childbearing age having a history of obstetric or gynecological procedure.

Advances in endometriosis treatment

Endometriosis is a common problem characterized by abdominal pain, back pain, pain with intercourse, dysfunctional uterine bleeding, and infertility. The cause of endometriosis is not well understood, but advances in treatment have been made. Primary care clinicians are uniquely situated to improve patient outcomes by making informed treatment decisions.

Expression of adiponectin, leptin, and their receptors in ovarian endometrioma

OBJECTIVE

To evaluate the expression of leptin, leptin receptor (ObR), adiponectin, and adiponectin receptor (AdipoR) in ovarian endometriomas compared with normal endometrium, and to analyze relationships among adipokines and their receptors.

DESIGN

Experimental study.

SETTING

A clinic for the treatment of endometriosis and basic research laboratories.

PATIENT(S)

Forty-four women with endometriosis and 42 age-matched women with no laparoscopic evidence of endometriosis as control subjects.

INTERVENTION(S)

Endometrial tissue samples were obtained during laparoscopic surgery.

MAIN OUTCOME MEASURE(S)

Immunohistochemical staining for leptin, ObR, adiponectin, and AdipoR was performed with the use of tissue microarray. Clinical characteristics were reviewed from the patient's medical records. The effect of leptin on the expression of adiponectin was evaluated in endometriotic cell line using real-time reverse-transcription polymerase chain reaction.

RESULT(S)

Positive expression rates of leptin and ObR were significantly higher in ovarian endometrioma compared with normal endometrium, but those of adiponectin and AdipoR were similar (ovarian endometrioma vs. normal endometrium, respectively: leptin 100% vs. 59.5%; ObR 72.7% vs. 33.3%; adiponectin 31.8% vs. 42.9%; AdipoR 88.6% vs. 73.8%). Expression of adipokines and their receptors did not show any correlation with disease stage. A positive correlation was found between expression of ObR and adiponectin (correlation coefficient 0.488; P=.001). Leptin treatment in endometriotic cells induced mRNA expression of adiponectin.

CONCLUSION(S)

These data suggest that leptin and its receptor are induced in ovarian endometriomas, and that the leptin/ObR system regulates adiponectin gene expression in endometriotic cells.

Cellular and molecular basis for endometriosis-associated infertility

Endometriosis is a gynecological disease characterized by the presence of endometrial glandular epithelial and stromal cells growing in the extra-uterine environment. The disease afflicts 10%–15% of menstruating women causing debilitating pain and infertility. Endometriosis appears to affect every part of a woman’s reproductive system including ovarian function, oocyte quality, embryo development and implantation, uterine function and the endocrine system choreographing the reproductive process and results in infertility or spontaneous pregnancy loss. Current treatments are laden with menopausal-like side effects and many cause cessation or chemical alteration of the reproductive cycle, neither of which is conducive to achieving a pregnancy. However, despite the prevalence, physical and psychological tolls and health care costs, a cure for endometriosis has not yet been found. We hypothesize that endometriosis causes infertility via multifaceted mechanisms that are intricately interwoven thereby contributing to our lack of understanding of this disease process. Identifying and understanding the cellular and molecular mechanisms responsible for endometriosis-associated infertility might help unravel the confounding multiplicities of infertility and provide insights into novel therapeutic approaches and potentially curative treatments for endometriosis.

Pathogenesis of endometriosis: the role of genetics, inflammation and oxidative stress

INTRODUCTION

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity.

MATERIALS AND METHODS

The etiology of this multifactorial disease is still unresolved and an increasing number of studies suggest that genetic, hormonal, environmental, immunological and oxidative factors may all play an important role in the pathogenesis of this disorder.

CONCLUSIONS

In this literature review, inflammatory activity, oxidative stress as well as genetic abnormalities and mutations have been studied in an effort to identify factors predisposing to endometriosis.

Apoptosis of ectopic endometrial cells is impaired in women with endometriosis

Purpose

This study was performed to assess the apoptotic index and Bcl-2 expression in ectopic endometrium of patients with endometriosis and in eutopic endometrium of patients without endometriosis, according to the phase of the menstrual cycle.

Methods

A total of eight patients with endometriosis and in eutopic endometrium of eight patients without endometriosis, according to the phase of the menstrual cycle. Samples were collected during surgical procedures and histologic sections were stained with hematoxylin-eosin and underwent morphometric analysis for assessment of the apoptotic index. TUNEL immunohistochemical assay was performed to validate the morphologic criteria used for quantification of apoptosis.

Results

The apoptotic index was significantly lower in the ectopic endometrium of patients with endometriosis in comparison to the eutopic endometrium of patients without endometriosis, regardless of the menstrual cycle phase. No statistically significant difference in endometrial Bcl-2 expression was observed among patients with and without endometriosis.

Conclusions

We conclude that ectopic endometrial tissues from women with endometriosis are less susceptible to apoptosis and these cells demonstrate an increased ability to survive and higher chances to colonize and grow in ectopic sites - important factors in the pathogenesis of endometriosis.