Expression profile of extracellular matrix and adhesion molecules in the development of endometriosis in a mouse model

Rodent Animal Models of Endometriosis-Associated Pain: Unmet Needs and Resources Available for Improving Translational Research in Endometriosis

Chronic pain induced by endometriosis is a maladaptive pain experienced by half of women with this disease. The lack of pharmacological treatments suitable for the long-term relief of endometriosis-associated pain, without an impact on fertility, remains an urgent unmet need. Progress has been slowed by the absence of a reproducible rodent endometriosis model that fully replicates human physiopathological characteristics, including pain symptoms. Although pain assessment in rodents is a complicated task requiring qualified researchers, the choice of the behavioral test is no less important, since selecting inappropriate tests can cause erroneous data. Pain is usually measured with reflex tests in which hypersensitivity is evaluated by applying a noxious stimulus, yet this ignores the associated emotional component that could be evaluated via non-reflex tests. We conducted a systematic review of endometriosis models used in rodents and the number of them that studied pain. The type of behavioral test used was also analyzed and classified according to reflex and non-reflex tests. Finally, we determined the most used reflex tests for the study of endometriosis-induced pain and the main non-reflex behavioral tests utilized in visceral pain that can be extrapolated to the study of endometriosis and complement traditional reflex tests.

hsa-miR-340-5p inhibits epithelial–mesenchymal transition in endometriosis by targeting MAP3K2 and inactivating MAPK/ERK signaling

Increasing evidence has verified the indispensable effect of microRNAs (miRNAs) in the biological processes of human diseases, including endometriosis. hsa-miR-340-5p was reported to display a low level in patients with endometriosis, but the detailed function of miR-340-5p in endometriosis is unclarified. RT-qPCR was used for the assessment of RNA levels of miR-340-5p and its downstream target genes in endometrial stromal cells (ESCs). Western blotting and Transwell assays revealed that upregulation of miR-340-5p suppressed the migration, invasiveness, and epithelial–mesenchymal transition (EMT) in ESCs. Bioinformatics tools were used to predict miR-340-5p downstream genes. Luciferase reporter assay displayed that miR-340-5p could bind to messenger RNA mitogen-activated protein kinase kinase kinase 2 (MAP3K2). MAP3K2 was targeted by miR-349-5p and could reverse the influence of miR-340-5p. miR-340-5p exerted its impact on the invasive characters of ESCs by inactivating the MAP3K2-mediated MAPK/ERK signaling. In conclusion, miR-340-5p restrains cell migration, invasiveness, and EMT in ESCs by targeting MAP3K2 and inactivating MAPK/ERK signaling.

Expression of cellular adherent and invasive molecules in recurrent ovarian endometriosis

Objective

This study aimed to examine expression of cellular adhesion molecules and metalloproteinases of the extracellular matrix in ectopic endometrium for evaluating their roles in recurrence of endometriosis.

Methods

This study retrospectively analyzed 49 female patients (mean age: 30.1±5.5 years) with endometriomas who had undergone two separate operations. After a maximum follow-up of 80 months, all participants were divided into the recurrent group or nonrecurrent (control) group. Samples were immunostained for epithelial cadherin (E-cadherin), β-catenin, urokinase plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-2, and extracellular matrix metalloproteinase inducer (EMMPRIN).

Results

In the recurrent group, E-cadherin concentrations in the membrane and cytoplasm of ectopic endometrial glandular cells were significantly reduced, while those of MMP-9 and EMMPRIN were higher than those in the control group. Additionally, uPA concentrations in the membrane and cytoplasm of ectopic endometrial glandular, stromal, and vascular endothelial cells were significantly higher in the recurrent group than in the control group. Tissue inhibitor of matrix metalloproteinase-2 and β-catenin concentrations were similar between the groups.

Conclusion

E-cadherin, MMP-9, and associated factors may contribute to development of endometriosis. E-cadherin, MMP-9, and uPA may act as potential markers for detection of recurrence of endometriosis.

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

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

Discovery of non-invasive biomarkers for the diagnosis of endometriosis

Background

Endometriosis is a common gynaecological disorder affecting 5-10% of women of reproductive age who often experience chronic pelvic pain and infertility. Definitive diagnosis is through laparoscopy, exposing patients to potentially serious complications, and is often delayed. Non-invasive biomarkers are urgently required to accelerate diagnosis and for triaging potential patients for surgery.

Methods

This retrospective case control biomarker discovery and validation study used quantitative 2D-difference gel electrophoresis and tandem mass tagging-liquid chromatography-tandem mass spectrometry for protein expression profiling of eutopic and ectopic endometrial tissue samples collected from 28 cases of endometriosis and 18 control patients undergoing surgery for investigation of chronic pelvic pain without endometriosis or prophylactic surgery. Samples were further sub-grouped by menstrual cycle phase. Selected differentially expressed candidate markers (LUM, CPM, TNC, TPM2 and PAEP) were verified by ELISA in a set of 87 serum samples collected from the same and additional women. Previously reported biomarkers (CA125, sICAM1, FST, VEGF, MCP1, MIF and IL1R2) were also validated and diagnostic performance of markers and combinations established.

Results

Cycle phase and endometriosis-associated proteomic changes were identified in eutopic tissue from over 1400 identified gene products, yielding potential biomarker candidates. Bioinformatics analysis revealed enrichment of adhesion/extracellular matrix proteins and progesterone signalling. The best single marker for discriminating endometriosis from controls remained CA125 (AUC = 0.63), with the best cross-validated multimarker models improving the AUC to 0.71-0.81, depending upon menstrual cycle phase and control group.

Conclusions

We have identified menstrual cycle- and endometriosis-associated protein changes linked to various cellular processes that are potential biomarkers and that provide insight into the biology of endometriosis. Our data indicate that the markers tested, whilst not useful alone, have improved diagnostic accuracy when used in combination and demonstrate menstrual cycle specificity. Tissue heterogeneity and blood contamination is likely to have hindered biomarker discovery, whilst a small sample size precludes accurate determination of performance by cycle phase. Independent validation of these biomarker panels in a larger cohort is however warranted, and if successful, they may have clinical utility in triaging patients for surgery.

Transforming growth factor β1 enhances adhesion of endometrial cells to mesothelium by regulating integrin expression

Endometriosis is the abnormal growth of endometrial cells outside the uterus, causing pelvic pain and infertility. Furthermore, adhesion of endometrial tissue fragments to pelvic mesothelium is required for the initial step of endometriosis formation outside uterus. TGF-β1 and adhesion molecules importantly function for adhesion of endometrial tissue fragments to mesothelium outside uterus. However, the function of TGF-β1 on the regulation of adhesion molecule expression for adhesion of endometrial tissue fragments to mesothelium has not been fully elucidated. Interestingly, transforming growth factor β1 (TGF-β1) expression was higher in endome-triotic epithelial cells than in normal endometrial cells. The adhesion efficiency of endometriotic epithelial cells to meso-thelial cells was also higher than that of normal endometrial cells. Moreover, TGF-β1 directly induced the adhesion of endometrial cells to mesothelial cells through the regulation of integrin of αV, α6, β1, and β4 via the activation of the TGF-β1/TGF-βRI/Smad2 signaling pathway. Conversely, the adhesion of TGF-β1-stimulated endometrial cells to mesothelial cells was clearly reduced following treatment with neutralizing antibodies against specific TGF-β1-mediated integrins αV, β1, and β4 on the endometrial cell membrane. Taken together, these results suggest that TGF-β1 may act to promote the initiation of endometriosis by enhancing integrin-mediated cell-cell adhesion.

Endometriosis Is a Cause of Infertility. Does Reactive Oxygen Damage to Gametes and Embryos Play a Key Role in the Pathogenesis of Infertility Caused by Endometriosis?

Approximately, 10-15% of women of reproductive age are affected by endometriosis, which often leads to infertility. Endometriosis often has an inherited component, and several causative predisposing factors are hypothesized to underlie the pathogenesis of endometriosis. One working hypothesis is the theory of retrograde menstruation. According to the theory of retrograde menstruation, components of refluxed blood, including apoptotic endometrial tissue, desquamated menstrual cells, lysed erythrocytes, and released iron, induce inflammation in the peritoneal cavity. This in turn activates macrophage release of reactive oxygen species (ROS), leading to oxidative stress via the respiratory burst. Refluxed blood promotes the Fenton reaction, terminating in the production of hydroxyl radical, the most potently destructive ROS. In this article, we review the papers that demonstrate decreased quantity and quality of oocytes and embryos retrieved from IVF/ICSI patients with endometriosis. We discuss literature data demonstrating that ROS are generated in endometriotic tissues that have physical proximity to gametes and embryos, and demonstrating adverse impacts on oocyte, sperm and embryo microtubule apparatus, chromosomes, and DNA. Data that addresses the notions that endometriosis causes oocyte and fetal aneuploidy and that these events are mediated by ROS species are also discussed. Literature data are also discussed that employ use of anti-oxidant molecules to evaluate the importance of ROS-mediated oxidative damage in the pathogenesis of endometriosis. Studies are discussed that have employed anti-oxidants compounds as therapeutics to improve oocyte and embryo quality in infertile subjects, and improve fertility in patients with endometriosis.

Endometriosis: Epidemiology, Diagnosis and Clinical Management

Purpose of review

Endometriosis is a disease of adolescents and reproductive-aged women characterized by the presence of endometrial tissue outside the uterine cavity and commonly associated with chronic pelvic pain and infertility. Here we review the epidemiology of endometriosis as well as potential biomarkers for detection and with the goal of highlighting risk factors that could be used in combination with biomarkers to identify and treat women with endometriosis earlier..

Recent findings

Early age at menarche, shorter menstrual length, and taller height are associated with a higher risk of endometriosis while parity, higher body mass index (BMI) and smoking are associated with decreased risk. Endometriosis often presents as infertility or continued pelvic pain despite treatment with analgesics and cyclic oral contraceptive pills.

Summary

Despite a range of symptoms, diagnosis of endometriosis is often delayed due to lack of non-invasive, definitive and consistent biomarkers for diagnosis of endometriosis. Hormone therapy and analgesics are used for treatment of symptomatic endometriosis. However, the efficacy of these treatments are limited as endometriosis often recurs. In this review, we describe potential diagnostic biomarkers and risk factors that may be used as early non-invasive in vitro tools for identification of endometriosis to minimize diagnostic delay and improve reproductive health of patients.

Effect of induced peritoneal endometriosis on oocyte and embryo quality in a mouse model

PURPOSE

To assess the impact of peritoneal endometriosis on oocyte and embryo quality in a mouse model.

METHODS

Peritoneal endometriosis was surgically induced in 33 B6CBA/F1 female mice (endometriosis group, N = 17) and sham-operated were used as control (sham group, N = 16). Mice were superovulated 4 weeks after surgery and mated or not, to collect E0.5-embryos or MII-oocytes. Evaluation of oocyte and zygote quality was done by immunofluorescence under spinning disk confocal microscopy.

RESULTS

Endometriosis-like lesions were observed in all mice of endometriosis group. In both groups, a similar mean number of MII oocytes per mouse was observed in non-mated mice (30.2 vs 32.6), with a lower proportion of normal oocytes in the endometriosis group (61 vs 83 %, p < 0.0001). Abnormalities were incomplete extrusion or division of the first polar body and spindle abnormalities. The mean number of zygotes per mouse was lower in the endometriosis group (21 vs 35.5, p = 0.02) without difference in embryo quality.

CONCLUSIONS

Our results support that induced peritoneal endometriosis in a mouse model is associated with a decrease in oocyte quality and embryo number. This experimental model allows further studies to understand mechanisms of endometriosis-associated infertility.

Leptospira interrogans induces uterine inflammatory responses and abnormal expression of extracellular matrix proteins in dogs

Leptospira interrogans (L. interrogans), a worldwide zoonosis, infect humans and animals. In dogs, four syndromes caused by leptospirosis have been identified: icteric, hemorrhagic, uremic (Stuttgart disease) and reproductive (abortion and premature or weak pups), and also it caused inflammation. Extracellular matrix (ECM) is a complex mixture of matrix molecules that is crucial to the reproduction. Both inflammatory response and ECM are closed relative to reproductive. The aim of this study was to clarify how L. interrogans affected the uterus of dogs, by focusing on the inflammatory responses, and ECM expression in dogs uterine tissue infected by L. interrogans. In the present study, 27 dogs were divided into 3 groups, intrauterine infusion with L. interrogans, to make uterine infection, sterile EMJH, and normal saline as a control, respectively. The uteruses were removed by surgical operation in 10, 20, and 30 days, respectively. The methods of histopathological analysis, ELISA, Western blot and qPCR were used. The results showed that L. interrogans induced significantly inflammatory responses, which were characterized by inflammatory cellular infiltration and high expression levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in uterine tissue of these dogs. Furthermore, L. interrogans strongly down-regulated the expression of ECM (collagens (CL) IV, fibronectins (FN) and laminins (LN)) in mRNA and protein levels. These data indicated that strongly inflammatory responses, and abnormal regulation of ECM might contribute to the proliferation of dogs infected by L. interrogans.

Expression of the gamma 2 chain of laminin-332 in eutopic and ectopic endometrium of patients with endometriosis

BACKGROUND

Endometrial cells, which are shed by retrograde menstruation, may aberrantly express molecules involved in invasion and migration, leading to endometriosis. The aim of this study was to investigate the expression of the laminin gamma 2 chain (LAMC2) in the tissues of women with and without endometriosis.

METHODS

Endometrial biopsy specimens were collected from healthy volunteers and from endometriosis patients. Biopsy specimens from the corresponding endometriotic lesions were also collected. The expression of laminin gamma 2 chain was evaluated by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Endometrial tissue from women with or without endometriosis showed constitutive expression of LAMC2 mRNA throughout the menstrual cycle. A higher mRNA level was observed in ectopic endometrium (Ec) from women with endometriosis compared with eutopic endometrium (Eu) from women with endometriosis. Immunohistochemistry revealed a varied pattern of laminin gamma 2 chain expression, with increased epithelial expression in eutopic endometrium from women with endometriosis compared with those without endometriosis.

CONCLUSIONS

The altered expression of laminin gamma 2 chain in eutopic endometrium from women with endometriosis may provide new opportunities for diagnosis and treatment.

Effect of traditional Chinese medicine (Xiaochaihu Tang) on the expression of MMP-2 and MMP-9 in rats with endometriosis

The aim of this study was to explore the effect of a traditional Chinese medicine (Xiaochaihu Tang, XCHT) on the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 in rats with endometriosis (EMs). A total of 48 specific-pathogen-free (SPF) female Sprague-Dawley (SD) rats were randomly divided into control (n=8) and EMs (n=40) groups. The EMs model was established using a surgical procedure. At 21 days, the rats with EMs were screened and divided into four subgroups (n=8): the model control, low-dose (7.5 g/kg) XCHT-treated, high-dose (15 g/kg) XCHT-treated and gestrinone-treated (0.5 mg/kg) groups. Following 21 days of treatment, the rats were sacrificed. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to examine the mRNA and protein levels of MMP-2 and MMP-9 in the endometrium. The expression levels of MMP-2 and MMP-9 were significantly increased in the rats with EMs compared with those in normal rats. Moreover, XCHT was able to significantly inhibit the expression of MMP-2 and MMP-9 compared with that in the model control group. In conclusion, XCHT was able to decrease the expression of MMP-2 and MMP-9 in the ectopic endometrium. The present results may provide a potential theoretical basis for the therapy of EMs.