Aberrant activation of signal transducer and activator of transcription-3 (STAT3) signaling in endometriosis

NLRC5 and autophagy combined as possible predictors in patients with endometriosis

OBJECTIVE

To investigate the levels of NLRC5 and autophagy in women with leiomyoma and endometriosis and the correlation between NLRC5 level and autophagy level.

DESIGN

Case-control study.

SETTING

Clinics.

PATIENT(S)

Sixty-five patients were recruited: 30 women with endometriosis were compared with 35 women with leiomyoma.

INTERVENTION(S)

Endometriosis was definitively diagnosed during surgery by laparoscopy or laparotomy and was confirmed by histopathological evaluation (n=30). Secretory phase ectopic endometrium tissues and eutopic endometrium tissues were obtained from 30 women with endometriosis. Control endometrium tissues were collected at hysterectomy from 35 women with leiomyoma. Immunohistochemical staining of NLRC5, LC3, Beclin1 and P62 were performed.

MAIN OUTCOME MEASURE(S)

A semiquantitative analysis was performed. Correlations between NLRC5 level and LC3, Beclin1, P62 levels were compared.

RESULT(S)

The expressions of NLRC5 and P62 in the ectopic and eutopic endometrium of endometriosis groups were significantly higher than that in the endometrium of leiomyoma group. And their expressions in ectopic endometrium were significantly up-regulated compared to the eutopic endometrium. The expressions of LC3 and Beclin1 were down-regulated in the ectopic and eutopic endometrium of endometriosis groups compared to the leiomyoma group. LC3 and Beclin1 levels were lower in ectopic endometrium than in the eutopic endometrium. There is a negative correlation between NLRC5 level and LC3, Beclin1 levels. There is a positive correlation between NLRC5 level and P62 level.

CONCLUSION(S)

There is a negative correlation between NLRC5 level and autophagy level. NLRC5 and autophagy combined may as promising predictors in patients with endometriosis.

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.

The Endometriotic Tumor Microenvironment in Ovarian Cancer

Women with endometriosis are at increased risk of developing ovarian cancer, specifically ovarian endometrioid, low-grade serous, and clear-cell adenocarcinoma. An important clinical caveat to the association of endometriosis with ovarian cancer is the improved prognosis for women with endometriosis at time of ovarian cancer staging. Whether endometriosis-associated ovarian cancers develop from the molecular transformation of endometriosis or develop because of the endometriotic tumor microenvironment remain unknown. Additionally, how the presence of endometriosis improves prognosis is also undefined, but likely relies on the endometriotic microenvironment. The unique tumor microenvironment of endometriosis is composed of epithelial, stromal, and immune cells, which adapt to survive in hypoxic conditions with high levels of iron, estrogen, and inflammatory cytokines and chemokines. Understanding the unique molecular features of the endometriotic tumor microenvironment may lead to impactful precision therapies and/or modalities for prevention. A challenge to this important study is the rarity of well-characterized clinical samples and the limited model systems. In this review, we will describe the unique molecular features of endometriosis-associated ovarian cancers, the endometriotic tumor microenvironment, and available model systems for endometriosis-associated ovarian cancers. Continued research on these unique ovarian cancers may lead to improved prevention and treatment options.

Interleukin 6 secretion from alternatively activated macrophages promotes the migration of endometriotic epithelial cells

Accumulating evidence has suggested an interaction between endometriotic cells and macrophages in the endometriotic microenvironment and the potential role of this interaction in the pathogenesis of endometriosis. However, how endometriotic cells communicate with macrophages to influence their function is poorly understood. In the present study, we found that the mRNA expression and production of CC chemokine ligand 2 (CCL2) were much higher in human endometriotic epithelial cells (11Z and 12Z) than those in human endometrial epithelial cells (HES). The inhibition of CCL2 action using neutralizing antibodies substantially suppressed macrophage migration induced by endometriotic epithelial cells. The endometriosis-associated macrophages (EAMs), which are the macrophages that are stimulated by the conditioned medium (CM) of human endometriotic cells, highly expressed the M2 phenotype markers (MRC1 and TREM2). In addition, the CM of EAMs significantly increased cell migration in 12Z cells, but no significant change was observed in cell growth. RT-PCR and antibody array analyses revealed that EAMs highly express and produce interleukin (IL) 6 compared to macrophages stimulated by the CM of HES cells. Moreover, the EAM-CM-induced migration and MMP2/9 expression in endometriotic cells were significantly attenuated by IL6 signaling inhibition. These results suggest a reciprocal activation of macrophages and endometriotic cells via the soluble factors CCL2 and IL6, which may contribute to the development of endometriosis.

Elevated levels of adrenomedullin in eutopic endometrium and plasma from women with endometriosis

OBJECTIVE

To test adrenomedullin (Adm, ADM) as a downstream target of signal transducer and activator of transcription 3 (STAT3) in endometrial cells and to test midregional proadrenomedullin (MR-proADM) as a biomarker of endometriosis.

DESIGN

Cross-sectional analysis of Adm expression in eutopic endometrium and of MR-proADM in plasma from women with and without endometriosis; and prospective study of MR-proADM levels in women with endometriosis undergoing surgical resection of ectopic lesions.

SETTING

Academic medical centers.

PATIENT(S)

Fifteen patients with endometriosis and 11 healthy control subjects who donated eutopic endometrial biopsies; and 28 patients with endometriosis and 19 healthy control subjects who donated plasma for MR-proADM analysis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adm mRNA levels according to quantitative real-time polymerase chain reaction after activation of STAT3 by interleukin-6 (IL-6) in Ishikawa cells; immunohistochemistry for ADM in eutopic endometrial biopsies from women with endometriosis compared with healthy donors; and MR-proADM levels measured by commercial immunoassay in plasma from healthy women and women with endometriosis who subsequently underwent surgical resection of ectopic lesions.

RESULT(S)

Activation of STAT3 by IL-6 up-regulated Adm mRNA expression in Ishikawa cells. ADM protein levels were elevated in the eutopic endometrium of women with endometriosis. MR-proADM concentrations were higher in women with endometriosis but were not correlated with disease stage, corrected by surgery, or predictive of fertility outcome.

CONCLUSION(S)

MR-proADM may be able to serve as a biomarker of endometriosis, but it is unknown whether elevated MR-proADM levels are secondary to the estrogenic and inflammatory properties of endometriosis or an inciting pathogenic factor.

MIG-6 suppresses endometrial epithelial cell proliferation by inhibiting phospho-AKT

Background

Aberrant hyperactivation of epithelial proliferation, AKT signaling, and association with unopposed estrogen (E2) exposure is the most common endometrial cancer dysfunction. In the normal uterus, progesterone (P4) inhibits proliferation by coordinating stromal-epithelial cross-talk, which we previously showed is mediated by the function of Mitogen-inducible gene 6 (Mig-6). Despite their attractive characteristics, non-surgical conservative therapies based on progesterone alone have not been universally successful. One barrier to this success has been the lack of understanding of the P4 effect on endometrial cells.

Method

To further understand the role of Mig-6 and P4 in controlling uterine proliferation, we developed a Sprr2f-cre driven mouse model where Mig-6 is specifically ablated only in the epithelial cells of the uterus (Sprr2f^cre+Mig-6^f/f). We examined P4 effect and regulation of AKT signaling in the endometrium of mutant mice.

Results

Sprr2f^cre+Mig-6^f/f mice developed endometrial hyperplasia. P4 treatment abated the development of endometrial hyperplasia and restored morphological and histological characteristics of the uterus. P4 treatment reduced cell proliferation which was accompanied by decreased AKT signaling and the restoration of stromal PGR and ESR1 expression. Furthermore, our in vitro studies revealed an inhibitory effect of MIG-6 on AKT phosphorylation as well as MIG-6 and AKT protein interactions.

Conclusions

These data suggest that endometrial epithelial cell proliferation is regulated by P4 mediated Mig-6 inhibition of AKT phosphorylation, uncovering new mechanisms of P4 action. This information may help guide more effective non-surgical interventions in the future.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4502-7) contains supplementary material, which is available to authorized users.

Genetic overlap between endometriosis and endometrial cancer: evidence from cross-disease genetic correlation and GWAS meta-analyses

Epidemiological, biological, and molecular data suggest links between endometriosis and endometrial cancer, with recent epidemiological studies providing evidence for an association between a previous diagnosis of endometriosis and risk of endometrial cancer. We used genetic data as an alternative approach to investigate shared biological etiology of these two diseases. Genetic correlation analysis of summary level statistics from genomewide association studies (GWAS) using LD Score regression revealed moderate but significant genetic correlation (rg  = 0.23, P = 9.3 × 10-3 ), and SNP effect concordance analysis provided evidence for significant SNP pleiotropy (P = 6.0 × 10-3 ) and concordance in effect direction (P = 2.0 × 10-3 ) between the two diseases. Cross-disease GWAS meta-analysis highlighted 13 distinct loci associated at P ≤ 10-5 with both endometriosis and endometrial cancer, with one locus (SNP rs2475335) located within PTPRD associated at a genomewide significant level (P = 4.9 × 10-8 , OR = 1.11, 95% CI = 1.07-1.15). PTPRD acts in the STAT3 pathway, which has been implicated in both endometriosis and endometrial cancer. This study demonstrates the value of cross-disease genetic analysis to support epidemiological observations and to identify biological pathways of relevance to multiple diseases.

Dysfunctional signaling underlying endometriosis: current state of knowledge

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity. It affects approximately 5-10% of women of reproductive age. Endometriosis is associated with dysmenorrhea, dyspareunia and, often, severe pelvic pain. In addition to pain, women with endometriosis often experience infertility. Defining the molecular etiology of endometriosis is a significant challenge for improving the quality of women's lives. Unfortunately, the pathophysiology of endometriosis is not well understood. Here, we summarize the potential causative factors of endometriosis in the following three categories: (1) dysregulation of immune cells in the peritoneal fluid and endometriotic lesions; (2) alteration of apoptotic signaling in retrograde menstrual tissue and cytotoxic T cells involved in endometriosis progression and (3) dysregulation of oxidative stress. Determining the molecular etiology of these dysregulated cellular signaling pathways should provide crucial clues for understanding initiation and progression of endometriosis. Moreover, improved understanding should suggest new molecular therapeutic targets that could improve the specificity of endometriosis treatments and reduce the side effects associated with current approaches.

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

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

Differentially expressed genes: OCT-4, SOX2, STAT3, CDH1 and CDH2, in cultured mesenchymal stem cells challenged with serum of women with endometriosis

Endometriosis is a common chronic gynecological disorder defined as the presence of ectopic functional endometrial tissues, outside uterine cavity, primarily on the pelvic peritoneum and the ovaries. Several studies revealed a correlation between aberrant stem-cell activity in the endometrium and endometriosis. Yet the molecular and cellular behaviors of mesnchymal stem cells in development of endometriosis are hampered by lack of invitro experiments. Our aim was to explore morphological and molecular changes associated with mesenchymal stem cells (MSCs) exposition to serum derived from women with severe endometriosis. Two cell cultures of MSCs isolated from endometrial tissues of two endometriosis-free women. Each cell culture was treated individually with the serum of women with endometriosis (experimental group/n = 7), and serum of women without endometriosis (control group/ n = 4) for 14 days. Quantitative Real-Time PCR was performed later to reveal expression of OCT-4, CDH1 and CDH2, STAT3 and SOX2 genes. Morphologically, cells showed no significant changes. However from molecular point of view, we found increased expression in OCT-4, CDH1 and CDH2. For STAT3 and SOX2 we did not find a significant difference. This study shows that endometriosis serum induced molecular changes in human endometrial MSCs (EnMSCs) that might be related to altered cell behavior which may be a step in differentiation that may be completed invivo by other factors to complete the process of transition. Further researches are needed for optimization to reach differentiation.

Abnormal Pathways in Endometriosis in Relation to Progesterone Resistance: A Review

Introduction

Endometriosis is an estrogen-dependent disorder, and recent studies suggest that progesterone resistance may contribute to the development and pathophysiology of the disorder. Based on this, identification of genetic and molecular perturbations in the endometrium of women with endometriosis is an important step towards understanding the pathogenesis of the disease, and the development of novel treatment and diagnostic strategies.

Methods

A systematic literature search in PubMed and Embase was performed, and 118 articles were identified for further screening. Two reviewers performed article screening independently using Covidence, and 16 studies fulfilled the inclusion criteria. The Newcastle-Ottawa Scale was used to assess the quality of these studies.

Results

This review presents data from eutopic endometrial biopsies from women with and without endometriosis. Several biomarkers related to a downregulated progesterone response were identified and discussed in detail.

Conclusions

Our review demonstrates significant results concerning the biomarkers investigated, which may substantiate the theory of progesterone resistance in women with endometriosis. However, further research is necessary to determine their specific role and relevance.

MIG-6 negatively regulates STAT3 phosphorylation in uterine epithelial cells

Endometrial cancer is the most common malignancy of the female genital tract. Progesterone (P4) has been used for several decades in endometrial cancer treatment, especially in women who wish to retain fertility. However, it is unpredictable which patients will respond to P4 treatment and which may have a P4 resistant cancer. Therefore, identifying the mechanism of P4 resistance is essential to improve the therapies for endometrial cancer. Mitogen-inducible gene 6 (Mig-6) is a critical mediator of progesterone receptor (PGR) action in the uterus. In order to study the function of Mig-6 in P4 resistance, we generated a mouse model in which we specifically ablated Mig-6 in uterine epithelial cells using Sprr2f-cre mice (Sprr2f^cre+Mig-6^f/f). Female mutant mice develop endometrial hyperplasia due to aberrant phosphorylation of STAT3 and proliferation of the endometrial epithelial cells. The results from our immunoprecipitation and cell culture experiments showed that MIG-6 inhibited phosphorylation of STAT3 via protein interactions. Our previous study showed P4 resistance in mice with Mig-6 ablation in Pgr positive cells (Pgr^cre/+Mig-6^f/f). However, Sprr2f^cre+Mig-6^f/f mice were P4 responsive. P4 treatment significantly decreased STAT3 phosphorylation and epithelial proliferation in the uterus of mutant mice. We showed that Mig-6 has an important function of tumor suppressor via inhibition of STAT3 phosphorylation in uterine epithelial cells and the anti-tumor effects of P4 are mediated by the endometrial stroma. This data helps to develop a new signaling pathway in the regulation of steroid hormones in the uterus, and to overcome P4 resistance in human reproductive diseases, such as endometrial cancer.

KRAS Activation and over-expression of SIRT1/BCL6 Contributes to the Pathogenesis of Endometriosis and Progesterone Resistance

Endometriosis is an inflammatory condition that is associated with progesterone resistance and cell proliferation, resulting in pain, infertility and pregnancy loss. We previously demonstrated phosphorylation of STAT3 in eutopic endometrium of infertile women with this disorder leading to over-expression of the oncogene BCL6 and stabilization of hypoxia-induced factor 1 alpha (HIF-1α). Here we report coordinated activation of KRAS and over-expression of Sirtuin 1 (SIRT1), a histone deacetylase and gene silencer, in the eutopic endometrium from women with endometriosis throughout the menstrual cycle. The mice with conditional activation of KRAS in the PGR positive cells reveal an increase of SIRT1 expression in the endometrium compared to control mice. The expression of progesterone receptor target genes including the Indian Hedgehog pathway genes are significantly down-regulated in the mutant mice. SIRT1 co-localizes with BCL6 in the nuclei of affected individuals and both proteins bind to and suppress the promoter of GLI1, a critical mediator of progesterone action in the Indian Hedgehog pathway, by ChIP analysis. In eutopic endometrium, GLI1 expression is reduced in women with endometriosis. Together, these data suggest that KRAS, SIRT1 and BCL6 are coordinately over-expressed in eutopic endometrium of women with endometriosis and likely participate in the pathogenesis of endometriosis.

Overexpression of Four Joint Box-1 Protein (FJX1) in Eutopic Endometrium From Women With Endometriosis

The four jointed box 1 (FJX1) is a regulator of angiogenesis, and the levels of FJX1 are increased in several types of cancer. Angiogenesis plays a critical role in endometrial growth as well as in several gynecologic disorders including endometriosis. However, the function of FJX1 has not been studied in endometriosis. Therefore, we examined the levels of FJX1 in eutopic endometrium from women with or without endometriosis. The levels of FJX1 protein did not change in endometrial cells during the menstrual cycle in endometrium from women without endometriosis. However, its levels were significantly higher in the secretory phase of the eutopic endometrium from women with endometriosis when compared to women without endometriosis. Hypoxia-inducible factor-1α (HIF1α) is known as a key mediator of endometriosis by regulating genes essential to estrogen production, angiogenesis, proliferation, inflammation, and extracellular invasion. It has been reported that FJX1 induces an increase in HIF1α through posttranslational stabilization. The results of our Western blot analysis reveal a significant positive correlation between FJX1 and HIF1α proteins in endometrium of women with and without endometriosis. This overexpression of FJX1 was confirmed by sequential analysis of the eutopic endometrium during endometriosis progression, using an induced model of endometriosis in the baboon. Therefore, our results suggest that high levels of FJX1 proteins may play an important role in the pathogenesis of endometriosis.

Endometrial receptivity in the eutopic endometrium of women with endometriosis: it is affected, and let me show you why

The endometrium maintains complex controls on proliferation and apoptosis as part of repetitive menstrual cycles that prepare the endometrium for the window of implantation and pregnancy. The reliance on inflammatory mechanisms for both implantation and menstruation creates the opportunity in the setting of endometriosis for establishment of chronic inflammation that is disruptive to endometrial receptivity, causing both infertility and abnormal bleeding. Clinically, there can be little doubt that the endometrium of women with endometriosis is less receptive to embryo implantation, and strong evidence exists to suggest that endometrial changes are associated with decreased cycle fecundity as a result of this disease. Here we provide unifying concepts regarding those changes and how they are coordinated to promote progesterone resistance and estrogen dominance through aberrant cell signaling pathways and reduced expression of key homeostatic proteins in eutopic endometrium of women with endometriosis.

Hypoxia-inhibited DUSP2 expression promotes IL-6/STAT3 signaling in endometriosis

PROBLEM

How does hypoxia-mediated downregulation of dual-specificity phosphatase-2 (DUSP2) promote the development of endometriotic lesions?

METHOD OF STUDY

The levels of IL-6 and DUSP2 were assessed in eutopic stromal cells with DUSP2 knockdown or hypoxia treatment. Bromodeoxyuridine (BrdU) incorporation was applied for evaluating cell proliferation. The protein levels of DUSP2, cleaved caspase-3, phosphorylated STAT3, and STAT3 were analyzed using immunoblot.

RESULTS

The genomewide analysis of cells with DUSP2 overexpression indicated IL-6 regulates multiple pathways related to inflammation, proliferation, and apoptosis. DUSP2 overexpression significantly suppressed IL-6 expression, while DUSP2 knockdown promoted IL-6 expression. The hypoxia-treated eutopic stromal cells expressed higher levels of IL-6, recapitulating the elevated levels of IL-6 in ectopic stromal cells. The treatment with IL-6 elicited the phosphorylation of STAT3, mimicking the elevated levels of phosphorylated STAT3 in the ectopic stromal cells. The IL-6-treated eutopic stromal cells showed more BrdU incorporation and less cleaved caspase-3, which can be reversed by STAT3 inhibitor.

CONCLUSION

Hypoxia-induced IL-6 production in endometriotic lesions is mediated via downregulation of DUSP2, which causes aberrant activation of STAT3 signaling pathway and helps the endometriotic cells survive under the ectopic environment.

Endometrial BCL6 Overexpression in Eutopic Endometrium of Women With Endometriosis

The objective of this study was to examine B-cell CLL/lymphoma 6 (BCL6) expression in human eutopic endometrium across the menstrual cycle in women with and without endometriosis and to establish a cutoff for future studies. This design was a series of case-control studies in tertiary University teaching hospitals. We examined BCL6 expression by messenger RNA and immunohistochemically in prospectively collected samples in both the proliferative (P) and the secretory phases. BCL6 is minimally increased in the mid-secretory phase of the menstrual cycle compared to the P phase in normal patients. BCL6 protein expression was significantly higher in the secretory phase of patients with endometriosis (n = 29) versus fertile controls without endometriosis at laparoscopy (n = 20; P < .0001). Normal fertile controls (n = 28) recruited for endometrial biopsy also had low levels of secretory phase BCL6 expression compared to women with unexplained infertility (UI; n = 119). A receiving-operator characteristic analysis of these data revealed an area under the curve of 94% (95% confidence interval 85%-100%; P < .0001) with an HSCORE cutoff of 1.4 to differentiate cases with and without endometriosis. Using this cutoff value, BCL6 was positive in 88% of cases with UI. Laparoscopic examination of a subset of 65 patients confirmed abnormalities in 98% of cases; 61 (93.8%) were found to have endometriosis, 3 (4.6%) with hydrosalpinx, and 1 (1.5%) with a normal pelvis. These data suggest that BCL6 is a promising candidate as a single diagnostic biomarker for detection of endometriosis in women with otherwise UI and may be associated with endometrial dysfunction, including progesterone resistance.

Niclosamide As a Potential Nonsteroidal Therapy for Endometriosis That Preserves Reproductive Function in an Experimental Mouse Model

Endometriosis causes severe chronic pelvic pain and infertility. Because the standard medication and surgical treatments of endometriosis show high recurrence of symptoms, it is necessary to improve current treatment options. In the initial study, we examined whether niclosamide can be a useful drug for endometriosis in a preclinical setting. Endometriotic implants were induced using an established mouse model involving transimplantation of mouse endometrial fragments to the peritoneal wall of recipient mice. When the recipient mice were treated with niclosamide for 3 weeks, niclosamide reduced the size of endometriotic implants with inhibition of cell proliferation, and inflammatory signaling including RELA (NFKB) and STAT3 activation, but did not alter expression of steroid hormone receptors. To identify genes whose expression is regulated by niclosamide in endometriotic implants, RNA-sequencing was performed, and several genes downregulated by niclosamide were related to inflammatory responses, WNT and MAPK signaling. In a second study designed to assess whether niclosamide affects reproductive function, the recipient mice started receiving niclosamide after the induction of endometriosis. Then, the recipient mice were mated with wild type males, and treatments continued until the pups were born. Niclosamide treated recipient mice became pregnant and produced normal size and number of pups. These results suggest that niclosamide could be an effective therapeutic drug, and acts as an inhibitor of inflammatory signaling without disrupting normal reproductive function.

Comprehensive study of angiogenic factors in women with endometriosis compared to women without endometriosis

OBJECTIVE

Endometriosis is a benign gynaecological disease, affecting women during their reproductive years. Angiogenesis represents a crucial step in the pathogenesis of endometriosis, because endometriotic lesions require neovascularization. In this study several angiogenesis-related genes have been studied in the context of endometriosis. Some of the analyzed angiogenic factors as well as their interactions were studied the first time regarding a possible association with endometriosis.

STUDY DESIGN

This case-control study consisted of 205 biopsies of 114 patients comprising 61 endometriosis patients and 53 control patients. Among them in 29 cases paired samples were obtained. VEGFA, VEGFR2, HIF1A, HGF, NRP1, PDGFB, FGF18, TNFα, TGFB2, EPHB4, EPO and ANG mRNA expression was analyzed by qRT-PCR in ectopic tissue samples, in eutopic endometrium of women with and without endometriosis, and in unaffected peritoneum of women with and without endometriosis.

RESULTS

VEGFR2, HIF1A, HGF, PDGFB, NRP1 and EPHB4 are overexpressed in ectopic lesions compared to eutopic tissues. VEGFR2, HGF, PDGFB, NRP1, and EPHB4 showed highest mRNA levels in peritoneal implants, in contrast HIF1A showed the highest expression in ovarian endometriomas. Correlation analyses of angiogenic factors in ectopic lesions revealed the strongest associations between VEGFR2, PDGFB, and EPHB4. We further showed a significant upregulation of VEGFR2, HIF1A and EPHB4 in eutopic endometrium of women with endometriosis compared to that of controls and a trend towards upregulation of HGF. Additionally, a significant downregulation for HIF1A, HGF and EPHB4 was observed in unaffected peritoneal tissues of women with endometriosis compared to controls.

CONCLUSION

We identified new genes (EPHB4 and NRP1) that may contribute to angiogenesis in endometriosis beside known factors (VEGFA, VEGFR2, HIF1A, HGF, and PDGFB). Correlation studies revealed the putative importance of EBHB4 in association with endometriosis. Our analyses support preliminary reports that angiogenic factors seem to be differently expressed in peritoneal implants, ovarian endometriomas and deep infiltrating endometriosis. Our observation that angiogenic factors are differently expressed in the unaffected peritoneum of women with endometriosis compared to women without endometriosis underlines the importance of the peritoneum in the establishment of endometriosis.

Protein Inhibitor of Activated STAT3 (PIAS3) Is Down-Regulated in Eutopic Endometrium of Women with Endometriosis

Endometriosis is a major cause of chronic pelvic pain and infertility. Activation of STAT3 appears central to the inflammatory phenotype of eutopic endometrium in women with endometriosis. However, the molecular mechanism by which this occurs remains unknown. Our objective is to determine how STAT3 activity is regulated in endometriosis. Protein inhibitor of activated STAT3 (PIAS3) is a negative regulator of STAT3 activity. We examined the levels of PIAS3 in endometrium from women with and without endometriosis using Western blot analysis and immunohistochemistry. Levels of PIAS3 are significantly lower, in contrast with phosphorylation of STAT3, in women with endometriosis compared to women without endometriosis. Furthermore, induction of endometriosis in the baboon showed a significant reduction of PIAS3 expression during the progression of the disease. Interferon-γ (INFγ) reduces PIAS3 protein levels and increases phospho-STAT3 levels through CXCL10 in endometrial cells, Ishikawa, and 12Z cells. These results suggest that attenuation of PIAS3 causes aberrant activation of STAT3 in endometriosis, leading to inflammatory changes that may impair fertility or cause pain.

Local and systemic factors and implantation: what is the evidence?

Significant progress has been made in the understanding of embryonic competence and endometrial receptivity since the inception of assisted reproductive technology. The endometrium is a highly dynamic tissue that plays a crucial role in the establishment and maintenance of normal pregnancy. In response to steroid sex hormones, the endometrium undergoes marked changes during the menstrual cycle that are critical for acceptance of the nascent embryo. There is also a wide body of literature on systemic factors that impact assisted reproductive technology outcomes. Patient prognosis is impacted by an array of factors that tip the scales in her favor or against success. Recognizing the local and systemic factors will allow clinicians to better understand and optimize the maternal environment at the time of implantation. This review will address the current literature on endometrial and systemic factors related to impaired implantation and highlight recent advances in this area of reproductive medicine.

Expression of GRIM-19 in adenomyosis and its possible role in pathogenesis

OBJECTIVE

To study the expression of the gene associated with retinoid-interferon (IFN)-induced mortality 19 (GRIM-19) in the endometrial tissue of patients with adenomyosis and to describe the possible pathogenic mechanisms of this phenomenon.

DESIGN

Experimental study using human samples and cell lines.

SETTING

University-affiliated hospital.

PATIENT(S)

Ectopic and eutopic endometrial tissues were obtained from 30 patients with adenomyosis, whereas normal endometrial specimens were obtained from 10 control patients without adenomyosis.

INTERVENTION(S)

Patients with rapid pathology report-confirmed adenomyosis were recruited, and eutopic and ectopic endometrial tissue samples were collected from patients who had undergone hysterectomies by either the transabdominal or laparoscopic method at Qilu Hospital. Normal endometrial tissue was collected from a group of control patients without adenomyosis.

MAIN OUTCOME MEASURE(S)

Immunohistochemistry (IHC) was performed to evaluate the expression of GRIM-19, phospho-signal transducer and activator of transcription 3 (Y705) (Y705) (pSTAT3(Y705)), and vascular endothelial growth factor (VEGF) in endometrial tissue samples. The protein levels of GRIM-19, pSTAT3(Y705), STAT3, and VEGF were detected by Western blot. Apoptosis in endometrial specimens was assayed by TUNEL. Immunohistochemistry with an antibody directed against CD34 was performed to detect new blood vessels in the endometrial tissue. GRIM-19 small interfering RNA and a recombinant plasmid carrying GRIM-19 were constructed to evaluate the effects of GRIM-19 on the downstream factors pSTAT3(Y705), STAT3, and VEGF in Ishikawa cells.

RESULT(S)

The expression of GRIM-19 was down-regulated in the eutopic endometria of patients with adenomyosis compared with the endometria of patients in the control group, and it was further reduced in the endometrial glandular epithelial cells of adenomyotic lesions. Apoptosis was reduced in the eutopic endometrium compared with the control group, and it was significantly reduced in ectopic endometrial tissues. In addition, the ectopic and eutopic endometria of patients with adenomyosis displayed a much higher microvessel density. In the eutopic and ectopic endometria of patients with adenomyosis, the expression levels of pSTAT3(Y705) and VEGF were significantly higher than in the controls. Furthermore, down-regulation of GRIM-19 in Ishikawa cells significantly promoted the activation of both pSTAT3(Y705) and its dependent gene VEGF.

CONCLUSION(S)

Aberrant expression of GRIM-19 may be associated with adenomyosis through the regulation of apoptosis and angiogenesis.

ARID1A Is Essential for Endometrial Function during Early Pregnancy

AT-rich interactive domain 1A gene (ARID1A) loss is a frequent event in endometriosis-associated ovarian carcinomas. Endometriosis is a disease in which tissue that normally grows inside the uterus grows outside the uterus, and 50% of women with endometriosis are infertile. ARID1A protein levels were significantly lower in the eutopic endometrium of women with endometriosis compared to women without endometriosis. However, an understanding of the physiological effects of ARID1A loss remains quite poor, and the function of Arid1a in the female reproductive tract has remained elusive. In order to understand the role of Arid1a in the uterus, we have generated mice with conditional ablation of Arid1a in the PGR positive cells (Pgrcre/+Arid1af/f; Arid1ad/d). Ovarian function and uterine development of Arid1ad/d mice were normal. However, Arid1ad/d mice were sterile due to defective embryo implantation and decidualization. The epithelial proliferation was significantly increased in Arid1ad/d mice compared to control mice. Enhanced epithelial estrogen activity and reduced epithelial PGR expression, which impedes maturation of the receptive uterus, was observed in Arid1ad/d mice at the peri-implantation period. The microarray analysis revealed that ARID1A represses the genes related to cell cycle and DNA replication. We showed that ARID1A positively regulates Klf15 expression with PGR to inhibit epithelial proliferation at peri-implantation. Our results suggest that Arid1a has a critical role in modulating epithelial proliferation which is a critical requisite for fertility. This finding provides a new signaling pathway for steroid hormone regulation in female reproductive biology and furthers our understanding of the molecular mechanisms that underlie dysregulation of hormonal signaling in human reproductive disorders such as endometriosis.