Molecular aspects of development and regulation of endometriosis

Associations between internal exposure levels of persistent organic pollutants in adipose tissue and deep infiltrating endometriosis with or without concurrent ovarian endometrioma

Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue. Histologically, it appears as different sub-types, being peritoneal endometriosis, ovarian endometrioma (OvE) and deep infiltrating endometriosis (DIE), which are of major relevance due to their varying clinical presentations. A number of persistent organic pollutants (POPs) have been associated with the onset of endometriosis, yet the overall set of existing studies remains fairly divergent. In this preliminary case-control study we aimed to assess the potential associations between the internal exposure to POPs and the presence of DIE with or without concurrent OvE. Adipose tissue and serum samples were collected from surgically confirmed cases (n=55) and controls (n=44) enrolled during 2013 and 2015 in Pays de la Loire, France. Targeted pollutants (76 historical or more emerging POPs including dioxins, polychlorobiphenyls (PCB), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecanes (HBCDs) and organochlorine pesticides (OCPs) were quantified by chromatography coupled to mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated from unconditional logistic regression adjusted for known confounding variables. The results showed significant associations between DIE and adipose tissue levels of 1.2.3.7.8 - PeCDD, OCDF, PCB 105, 114, 118 and 123, PBDE 183, PBB 153, and several OCPs including trans‑nonachlor, cis‑heptachlor epoxide, dieldrin, β-hexachlorocyclohexane and hexachlorobenzene. The largest associations were observed for OCDF followed by cis‑heptachlor epoxide, exhibiting adjusted ORs (95% CI) of 5.42 (2.73-12.85) and 5.36 (2.44-14.84) per 1-SD increase, respectively. The stratified analysis comparing both disease sub-types suggested that adipose tissue exposure markers may be more associated with DIE concurrent with OvE, however these results need to be confirmed in a larger population.

miRNA expression profiling in formalin-fixed paraffin-embedded endometriosis and ovarian cancer samples

Endometriosis is an inflammatory pathology associated with a negative effect on life quality. Recently, this pathology was connected to ovarian cancer, in particular with endometrioid ovarian cancer. microRNAs (miRNAs) are a class of RNA transcripts ~19–22 nucleotides in length, the altered miRNA pattern being connected to pathological status. miRNAs are highly stable transcripts, and these can be assessed from formalin-fixed paraffin-embedded (FFPE) samples leading to the identification of miRNAs that could be developed as diagnostic and prognostic biomarkers, in particular those involved in malignant transformation. The aim of our study was to evaluate miRNA expression pattern in FFPE samples from endometriosis and ovarian cancer patients using PCR-array technology and also to compare the differential expression pattern in ovarian cancer versus endometriosis. For the PCR-array study, we have used nine macrodissected FFPE samples from endometriosis tissue, eight samples of ovarian cancers and five normal ovarian tissues. Quantitative real-time PCR (qRT-PCR) was used for data validation in a new patient cohort of 17 normal samples, 33 endometriosis samples and 28 ovarian cancer macrodissected FFPE samples. Considering 1.5-fold expression difference as a cut-off level and a P-value <0.05, we have identified four miRNAs being overexpressed in endometrial tissue, while in ovarian cancer 15 were differentially expressed (nine overexpressed and six downregulated). The expression level was confirmed by qRT-PCR for miR-93, miR-141, miR-155, miR-429, miR-200c, miR-205 and miR-492. Using the interpretative program Ingenuity Pathway Analysis revealed several deregulated pathways due to abnormal miRNA expression in endometriosis and ovarian cancer, which in turn is responsible for pathogenesis; this differential expression of miRNAs can be exploited as a therapeutic target. A higher number of altered miRNAs were detected in endometriosis versus ovarian cancer tissue, most of them being linked with epithelial-to-mesenchymal transition.

MicroRNA expression analysis in endometriotic serum treated mesenchymal stem cells

Endometriosis is defined by presence of endometrial-like-tissue outside the uterus. Recently, ectopic endometriotic lesions have been suggested to originate by abnormal differentiation of endometrial mesenchymal stem cells (eMSCs). MicroRNAs (miRNAs) play an important role in the pathophysiology of endometriosis. Through a PCR array approach, we aimed to assess the differential expression of microRNAs in human eMSC treated in culture with sera derived from women with severe endometriosis. Sera were collected from five patients with severe endometriosis and three control women and added individually in the culture medium to conduct experimental and control eMSC sets, respectively. Regular microscopic follow-up for cell morphology was performed. SYBR Green based real-time PCR array was used to assess the expression of 84 miRNAs. Bioinformatics analysis was done to predict the target genes of the significantly dysregulated miRNAs and their enriched biological processes and pathways. Thirty-two miRNAs were found significantly dysregulated in experimental cultures. Functional enrichment analysis revealed several endometriosis associated biological processes and pathways were enriched by target genes of these miRNAs. In conclusion, treatment of human eMSCs with sera of severe endometriosis cases affects the expression of certain miRNAs and their target genes. This may result in altering cell functions and consequently, endometriosis development.

Differential expression of EWI-2 in endometriosis, its functional role and underlying molecular mechanisms

AIM

We aimed to investigate EWI-2 expression in endometrium tissues collected from women with endometriosis at mRNA and protein levels, to evaluate its potential as a biomarker for endometriosis and to study its functional role via possible regulation of the PI3K/Akt signaling pathway.

METHODS

Endometrium tissues were collected from patients with endometriosis and healthy individuals. EWI-2 mRNA expression was evaluated using quantitative real-time PCR (qRT-PCR) while EWI-2 protein levels were determined by western blotting. For functional studies, EWI-2 shRNA was transfected in endometrial epithelial cells and the in vitro migration and invasion assays were performed using the Transwell chambers.

RESULTS

EWI-2 was significantly downregulated in tissues obtained from patients with endometriosis compared with healthy individuals (P < 0.0001). EWI-2 expression in the secretory phase was lower than that in the proliferative phase (P < 0.0001). Receiver-operator curve analysis of EWI-2 expression showed that the area under the curve for endometriosis diagnosis was 0.8942 (P = 0.003), 0.9643 (P = 0.0001), 0.9912 (P < 0.0001), and 0.9150 (P < 0.0001), respectively, for healthy women compared with women with endometriosis in matched comparisons of data originated from the proliferative, early, middle, and late secretory phases. Over the menstrual cycle, the expression of EWI-2 was significantly decreased in the eutopic tissues compared to the ectopic tissues. Further cellular and molecular analyses showed that EWI-2 inhibited cell migration and invasion via the Akt signaling.

CONCLUSION

Our findings suggested that downregulation of EWI-2 may contribute to endometriosis physiopathology and potentiate EWI-2 as a valuable diagnostic biomarker and therapeutic target for endometriosis.

Primiparous singleton women with endometriosis have an increased risk of preterm birth: Meta-analyses

Objective

The objective of this study was to assess the association between women with endometriosis and risk of preterm birth.

Methods

Two reviewers independently determined all prospective cohort study, retrospective cohort study, large population based cohort study, retrospective secondary analysis, and double blinded, multicentric, observational and cohort study, placebo-controlled, randomized clinical trial published using PubMed, Medline, Korea Education and Research Information Service, and Scopus from March 1994 through February 2016 without language restrictions comparing obstetric outcomes women with endometriosis and women without endometriosis. The meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Six studies met inclusion criteria, including 50,472 women. Among 50,472 pregnancies, 39,659 had endometriosis and 10,813 had no endometriosis. Meta-analyses were estimated with odds ratios and 95% confidence intervals using random effect analysis according to heterogeneity of studies.

Results

Data from six effect sizes from six studies involving 50,472 patients were enrolled. These meta-analyses showed women with endometriosis have an increased risk of preterm birth (odds ratio, 1.473; 95% confidence interval, 1.216 to 1.785).

Conclusion

These meta-analyses demonstrate women with endometriosis at pregnancy have an increased risk of preterm birth. Therefore, it is worthy for obstetrics to increase the careful inspection in women with endometriosis during pregnancy.

Endometrial Stromal and Epithelial Cells Exhibit Unique Aberrant Molecular Defects in Patients With Endometriosis

CONTEXT

Endometriosis is a chronic inflammatory disease that causes pain and infertility in women of reproductive age.

OBJECTIVE

To investigate the pathologic pathways in endometrial stromal and epithelial cells that contribute to the manifestation of endometriosis.

DESIGN

In vitro cellular and molecular analyses of isolated eutopic endometrial stromal and epithelial cells.

METHODS

Eutopic stromal and epithelial cells from endometriotic and normal patients were isolated by fluorescence-activated cell sorting for paired sibling RNA sequencing and microRNA microarray. Aberrant pathways were identified using ingenuity pathway analysis networks and confirmed with in vitro modulation of the affected pathways in stromal and epithelial cell cultures.

RESULTS

Both stromal versus epithelial cell types and paired endometriotic versus normal samples exhibited distinct hierarchical clustering. Compared to normal samples, there were 151 and 215 differentially expressed genes in the endometriotic stromal and epithelial populations, respectively, and concomitantly 9 and 16 differentially expressed microRNAs. Overall, endometriotic stromal and epithelial cells revealed distinct defects. In endometriotic stromal cells, key decidualization genes Zinc finger E-box Binding protein 1 (ZEB1), Heart And Neural crest Derivatives expressed 2 (HAND2), WNT4, and Interleukin 15 (IL-15) were found to be downregulated and Periostin (POSTN) and Matrix Metallopeptidase 7 (MMP7) were upregulated. Specifically, ZEB1 was downregulated in stromal cells by aberrant elevation in miR-200b. In contrast, ZEB1 was found to be upregulated in endometriotic epithelial cells through associated upregulation of transforming growth factor β1 (TGFβ1), inducer of the TGFβ1-Bone Morphogenetic Protein 2 (BMP2)-MMP2-Prostaglandin-endoperoxide Synthase 2 (COX2)-ZEB1 pathway, which activates epithelial-mesenchymal transition.

CONCLUSION

Manifestation of endometriosis involves dysregulation of unique molecular pathways within the diseased endometrial stromal and epithelial cells in the endometrium. Targeting the cell type-specific defects may offer a novel approach to treating endometriosis.

Anti-Endometriotic Effects of Pueraria Flower Extract in Human Endometriotic Cells and Mice

Pueraria flowers have been used as a vegetable and an ingredient for tea and jelly. In this study, we investigated the effects of Pueraria flower extract (PFE) on endometriosis, a common gynaecological disease characterised by local sterile inflammation of peritoneal cavity. PFE suppressed the adhesion of human endometriotic cells 11Z and 12Z to human mesothelial Met5A cells. In addition, PFE significantly inhibited the migration of 11Z and 12Z cells as shown by wound-healing and transwell migration assays. PFE reduced the protein and mRNA levels of matrix metalloproteinase (MMP)-2 and MMP-9 in endometriotic cells. Moreover, extracellular signal-regulated kinase (ERK)1/2 was activated by PFE treatment, and an ERK1/2 inhibitor, PD98059, significantly inhibited PFE-inhibited cell migration in endometriotic cells. Furthermore, PFE significantly suppressed endometriotic lesion formation in a mouse model. These data suggest that Pueraria flower is a potential anti-endometriotic agent for the inhibition of endometriotic cell adhesion, migration, and MMP expression.

Downregulation of autophagy gene expression in endometria from women with polycystic ovary syndrome

Autophagy, a process of controlled cellular self-digestion, could be involved in cyclic remodeling of the human endometrium. We investigated endometrial mRNA expression of 23 autophagy-related (ATG) genes and transcription factors in healthy controls (n = 12) and anovulatory polycystic ovary syndrome (PCOS) patients (n = 24), as well as in their subgroup (n = 12) before and after metformin treatment. The mRNA levels of transcription factor forkhead box protein O1 (FOXO1) and several molecules involved in autophagosome formation (ATG13, RB1-inducible coiled-coil 1), autophagosome nucleation (ATG14, beclin 1, SH3-domain GRB2-like endophilin B1), autophagosome elongation (ATG3, ATG5, γ-aminobutyric acid receptor-associated protein - GABARAP), and delivery of ubiquitinated proteins to autophagosomes (sequestosome 1), were significantly reduced in anovulatory PCOS compared to healthy endometrium. Free androgen index, but not free estrogen index, insulin levels, or body mass index, negatively correlated with the endometrial expression of ATG3, ATG14, and GABARAP in PCOS patients. Treatment of PCOS patients with metformin (2 g/day for 3 months) significantly increased the endometrial mRNA levels of FOXO1, ATG3, and UV radiation resistance-associated gene. These data suggest that increased androgen availability in PCOS is associated with metformin-sensitive transcriptional downregulation of endometrial autophagy.

Low Body Mass Index in Endometriosis Is Promoted by Hepatic Metabolic Gene Dysregulation in Mice

The gynecological disease endometriosis is characterized by the deposition and proliferation of endometrial cells outside the uterus and clinically is linked to low body mass index (BMI). Gene expression in the liver of these women has not been reported. We hypothesized that endometriosis may impact hepatic gene expression, promoting a low BMI. To determine the effect of endometriosis on liver gene expression, we induced endometriosis in female mice by suturing donor mouse endometrium into the peritoneal cavity and measuring the weight of these mice. Dual-energy X-ray absorptiometry (DEXA) scanning of these mice showed lower body weight and lower total body fat than controls. Microarray analysis identified 26 genes differentially regulated in the livers of mice with endometriosis. Six of 26 genes were involved in metabolism. Four of six genes were upregulated and were related to weight loss, whereas two genes were downregulated and linked to obesity. Expression levels of Cyp2r1, Fabp4, Mrc1, and Rock2 were increased, whereas Igfbp1 and Mmd2 expression levels were decreased. Lep and Pparg, key metabolic genes in the pathways of the six genes identified from the microarray, were also upregulated. This dysregulation was specific to metabolic pathways. Here we demonstrate that endometriosis causes reduced body weight and body fat and disrupts expression of liver genes. We suggest that altered metabolism mediated by the liver contributes to the clinically observed low BMI that is characteristic of women with endometriosis. These findings reveal the systemic and multiorgan nature of endometriosis.

Overexpression of chloride channel-3 is associated with the increased migration and invasion ability of ectopic endometrial cells from patients with endometriosis

STUDY QUESTION

Is chloride channel-3 (ClC-3) involved in regulating the biological behavior of endometrial stromal cells (ESCs)?

SUMMARY ANSWER

ClC-3 promotes endometriotic cell migration and invasion.

WHAT IS KNOWN ALREADY

ClC-3 plays a significant role in the migration and invasion of various kinds of cells.

STUDY DESIGN, SIZE, DURATION

An ITALIC! in vitro investigation of the effect of ClC-3 on the migration and invasion of ectopic ESCs from patients with endometriosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The ectopic and eutopic endometrial samples from 43 female patients with endometriosis and the endometrial samples from 39 non-endometriotic female patients were collected. Primary cells from these samples were isolated and cultured. Real-time RT-PCR, immunohistochemistry and western blot were used to detect the expression of ClC-3 and matrix metalloproteinase 9 (MMP-9). Small interfering RNA (siRNA) technology was employed to knock down ClC-3 expression. The migration and invasion ability of ESCs was measured by the transwell assay with uncoated or Matrigel-coated membranes.

MAIN RESULTS AND THE ROLE OF CHANCE

The expression of ClC-3 mRNA and proteins was significantly up-regulated in the ectopic tissues from endometriotic patients, while that in the eutopic endometrial tissues of the same patients did not significantly differ from that in non-endometriotic patients. The migration and invasion ability and MMP-9 expression was increased in the ESCs from ectopic endometrial tissues. The knockdown of ClC-3 expression by ClC-3 siRNA inhibited ESC migration and invasion and attenuated the expression of MMP-9. ClC-3 expression level was well-correlated to the clinical characteristics and symptoms of endometriosis patients, including infertility, dysmenorrhea, chronic pelvic pain, dyspareunia and diameter of endometriosis lesion.

LIMITATIONS, REASONS FOR CAUTION

Further studies are needed to examine the regulatory mechanism of estrogen on ClC-3 expression of ESCs.

WIDER IMPLICATIONS OF THE FINDINGS

ClC-3 is involved in the migration and invasion processes of ESCs and can regulate MMP-9 expression. Up-regulation of ClC-3 expression may contribute to endometriosis development by regulating MMP-9 expression.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Natural Science Foundation of China (81173064, 81272223, 81273539), the Ministry of Education of China (20124401110009), the Natural Science Foundation of Guangdong Province (S2011010001589) and the Science and Technology Programs of Guangdong (2013B051000059), Guangzhou (2013J500015) and Dongguan (2011108102006). The authors have no conflict of interest.

The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

BACKGROUND

Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

METHODS

We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia.

RESULTS

Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and vascular remodeling. In non-fertile cycles, progesterone withdrawal reduces TF and PAI-1 while increasing PA, MMPs and ET-1, causing menstrual-associated bleeding, fibrinolysis, ECM degradation and ischemia. First trimester decidual hemorrhage elicits later adverse outcomes including pregnancy loss, pre-eclampsia, abruption, IUGR and PTB. Decidual hemorrhage generates excess thrombin that binds to decidual cell-expressed protease-activated receptors (PARs) to induce chemokines promoting shallow placentation; such bleeding later in pregnancy generates thrombin to down-regulate decidual cell progesterone receptors and up-regulate cytokines and MMPs linked to PTB. Endometria of pLARC users display ischemia-induced excess vasculogenesis and progestin inhibition of spiral artery vascular smooth muscle cell proliferation and migration leading to dilated fragile vessels prone to bleeding. Moreover, aberrant TF-derived thrombin signaling also contributes to the pathogenesis of endometriosis via induction of angiogenesis, inflammation and cell survival.

CONCLUSION

Perivascular decidualized HESCs promote endometrial hemostasis during placentation yet facilitate menstruation through progestational regulation of hemostatic, proteolytic, and vasoactive proteins. Pathological endometrial hemorrhage elicits excess local thrombin generation, which contributes to pLARC associated AUB, endometriosis and adverse pregnancy outcomes through several biochemical mechanisms.

Comparative systems genetics view of endometriosis and uterine leiomyoma: Two sides of the same coin?

Endometriosis (EM) and uterine leiomyoma (UL) are two most frequent benign tumors of monoclonal origin affecting about 30% of all women in their reproductive age. Modern molecular technologies have made a tremendous impact in understanding both disorders. Here is the first comparative analysis of molecular mechanisms underlying development of EM and UL as it looks from the platform of systems genetics. Similarities and differences of EM and UL at their incipient stages are enlightened with special emphasis on their gene networks, gene expression, and epigenetic regulation, of pathologic development. The analysis substantiates a new hypothesis postulating tumors as outgrowths of the stem cells with mesenchymal commitment lineage (mSC) which migrate from the endometrium/myometrium junctional zone of the uterus. Comparative analysis has revealed basic similarities of molecular pathogenesis of EM and UL suggesting molecular syntropy of both disorders. Peculiarities of the epigenetic landscape determining development of mSC may explain the existence of different clinical forms of EM and UL as well as their unique clinical manifestation. Some perspectives for practical and scientific application in EM and UL studies of this new hypothesis are outlined.

rhTNFR: Fc Suppresses the Development of Endometriosis in a Mouse Model by Downregulating Cell Proliferation and Invasiveness

Tumor necrosis factor α (TNF-α), a proinflammatory cytokine, may play an important role in the pathogenesis of endometriosis; therefore, TNF-α inhibitors potentially have an effect on endometriosis. To investigate the effect of anti-TNF-α treatment on endometriosis, 2 TNF-α inhibitors: recombinant human TNF receptor: Fc fusion protein (rhTNFR: Fc) and TNF-α monoclonal antibody (TNF-α mAb) were used to treat human eutopic endometrial stromal cells (hESCs), and the effects on cell survival, cell cycle, and invasiveness were compared. It was found that rhTNFR: Fc suppressed the TNF-α-induced hESC survival and invasiveness but not TNF-α mAb. Recombinant human TNF receptor: Fc fusion protein decreased the S phase of hESC compared with the TNF-α-treated group. Then, we used a surgically induced mouse model of endometriosis to study the effect of rhTNFR: Fc treatment in vivo. The fluorescence intensity and the size of implanted endometriotic lesions in the mouse model were decreased by rhTNFR: Fc. In conclusion, rhTNFR: Fc suppresses hESC survival and invasiveness and decreases the fluorescence intensity and implant size in the mouse model of endometriosis.

Aging Chart: a community resource for rapid exploratory pathway analysis of age-related processes

Aging research is a multi-disciplinary field encompassing knowledge from many areas of basic, applied and clinical research. Age-related processes occur on molecular, cellular, tissue, organ, system, organismal and even psychological levels, trigger the onset of multiple debilitating diseases and lead to a loss of function, and there is a need for a unified knowledge repository designed to track, analyze and visualize the cause and effect relationships and interactions between the many elements and processes on all levels. Aging Chart (http://agingchart.org/) is a new, community-curated collection of aging pathways and knowledge that provides a platform for rapid exploratory analysis. Building on an initial content base constructed by a team of experts from peer-reviewed literature, users can integrate new data into biological pathway diagrams for a visible, intuitive, top-down framework of aging processes that fosters knowledge-building and collaboration. As the body of knowledge in aging research is rapidly increasing, an open visual encyclopedia of aging processes will be useful to both the new entrants and experts in the field.

Tissue Factor-Factor VII Complex As a Key Regulator of Ovarian Cancer Phenotypes

Tissue factor (TF) is an integral membrane protein widely expressed in normal human cells. Blood coagulation factor VII (fVII) is a key enzyme in the extrinsic coagulation cascade that is predominantly secreted by hepatocytes and released into the bloodstream. The TF–fVII complex is aberrantly expressed on the surface of cancer cells, including ovarian cancer cells. This procoagulant complex can initiate intracellular signaling mechanisms, resulting in malignant phenotypes. Cancer tissues are chronically exposed to hypoxia. TF and fVII can be induced in response to hypoxia in ovarian cancer cells at the gene expression level, leading to the autonomous production of the TF–fVII complex. Here, we discuss the roles of the TF–fVII complex in the induction of malignant phenotypes in ovarian cancer cells. The hypoxic nature of ovarian cancer tissues and the roles of TF expression in endometriosis are discussed. Arguments will be extended to potential strategies to treat ovarian cancers based on our current knowledge of TF–fVII function.

MiR-183 Regulates ITGB1P Expression and Promotes Invasion of Endometrial Stromal Cells

We applied in the previous study miRNA microarray screening analysis to identify several differentially expressed miRNAs, including miR-183 in normal, eutopic, and ectopic endometrium. Knockdown of miR-183 expression induced the invasiveness and inhibition of apoptosis in endometrial stromal cells. The current study aims to identify the miR-183 targets with relevance to cell functions in endometrial stromal cells, to verify the interaction of miR-183 with its target genes, and to confirm the role of miR-183 in the process of endometriosis. Using microarray analysis, we identified 27 differentially expressed genes (19 were upregulated and 8 downregulated), from which we selected 4 downregulated genes (ITGB1, AMIGO2, VAV3, and PSEN2) based on GO databases for functional analysis and significant pathway analysis. Western blotting analyses showed that integrin β1 (ITGB1), but not AMIGO2, was affected by miR-183 overexpression, whereas no protein expression of VAV3 and PSEN2 was detected. Luciferase reporter assay verified that ITGB1 is a target gene of miR-183. Moreover, we found that ITGB1 is overexpressed in the endometrium of endometriosis patients. Furthermore, overexpression of ITGB1 rescued the repressive effects of miR-183 on the invasiveness of endometrial stromal cells. These findings, together with the fact that ITGB1 is a critical factor for cell adhesion and invasiveness, suggest that miR-183 may be involved in the development of endometriosis by regulating ITGB1 in endometrial stromal cells.

Association of WNT4 polymorphisms with endometriosis in infertile patients

PURPOSE

Recently, several genome-wide association studies have demonstrated an association between endometriosis and markers located in or near to WNT4 gene. In order to assess the validity of the findings, we conducted a replication case-control study in a Brazilian population.

METHODS

Genetic association study comprising 400 infertile women with endometriosis and 400 fertile women as controls. TaqMan allelic discrimination technique was used to investigate the relationship between endometriosis and four single-nucleotide polymorphisms (rs16826658, rs3820282, rs2235529, and rs7521902) in WNT4 gene. Genotype distribution, allele frequency, and haplotype analysis of the WNT4 polymorphisms were performed. A p value <0.05 was considered significant.

RESULTS

The results revealed a significant association of rs16826658 (p = 7e-04) and rs3820282 (p = 0.048) single-nucleotide polymorphisms (SNPs) on WNT4 gene with endometriosis-related infertility, while rs2235529 and rs7521902 SNPs showed no difference between cases and controls.

CONCLUSIONS

Our results suggested that rs16826658 and rs3820282 polymorphisms on WNT4 gene might be involved in the pathogenesis of endometriosis in the infertile women studied. Analysis of WNT4 genetic variants might help to identify patients at high risk for disease development.

The Impact of Endometriosis across the Lifespan of Women: Foreseeable Research and Therapeutic Prospects

In addition to estrogen dependence, endometriosis is characterized by chronic pelvic inflammation. The impact of the chronic pelvic inflammatory state on other organ systems and women's health is unclear. Endometriosis associated chronic inflammation and potential adverse health effects across the lifespan render it imperative for renewed research vigor into the identification of novel biomarkers of disease and therapeutic options. Herein we propose a number of opportunities for research and development of new therapeutics to address the unmet needs in the treatment of endometriosis per se and its ancillary risks for other diseases in women across the lifespan.

Statins as Targeted "Magical Pills" for the Conservative Treatment of Endometriosis: May Potential Adverse Effects on Female Fertility Represent the "Dark Side of the Same Coin"? A Systematic Review of Literature

The aim of the study was to analyze all the available evidence from both in vitro and in vivo studies regarding the efficacy of statin therapy in the treatment of endometriosis, evaluating the potential efficacy, side effects, and contraindications of their administration in humans. We focused on defining the potential benefits that the administration of statins may have on patients affected by endometriosis and the possible adverse effects of such a therapy on ovarian function and fertility profile. According to our article selection criteria, we included in the review in vitro and in vivo studies performed on human or animal models. The systematic review of literature identified 24 eligible articles, 12 of which reported evidence regarding the effects of statins on endometrial/endometriotic cells and 12 regarding their effects on ovarian function and fertility. All articles seem to emphasize the utility of statin administration in the treatment of endometriosis due to their anti-proliferative/proapoptotic effects, their ability to reduce cell viability and migration, and the inhibition of angiogenesis and anti-inflammatory activities. Regarding the potential adverse effects on gonadal activities, steroidogenesis and fertility function, no conclusive data were collected in human models (excluding women affected by polycystic ovary syndrome in which significant decline of androgen levels was reported after statin treatment), while contrasting results were reported by studies conducted in in vitro and in vivo in animal models. Despite evidence supporting statins as the potential therapeutic agent for a targeted conservative treatment of endometriosis, the uncertainties regarding their impact on gonadal function may not define them as an appropriate therapy for all young fertile women.

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

STUDY QUESTION

Are STAT3 signaling molecules differentially expressed in endometriosis?

SUMMARY ANSWER

Levels of phospho-STAT3 and HIF1A, its downstream signaling molecule, are significantly higher in eutopic endometrium from women with endometriosis when compared with women without the disease.

WHAT IS KNOWN ALREADY

Endometriosis is an estrogen-dependent inflammatory condition. Interleukin 6 (IL-6) is an inflammatory survival cytokine known to induce prolonged activation of STAT3 via association with the IL-6 receptor.

STUDY DESIGN, SIZE, DURATION

Cross-sectional measurements of STAT3 and HIF1A protein levels in eutopic endometrium from women with endometriosis versus those without.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Levels of phospho-STAT3 (pSTAT3) and HIF1A were examined in the endometrium of patients with and without endometriosis as well as in a non-human primate animal model using western blot and immunohistochemical analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Levels of pSTAT3 were significantly higher in the eutopic endometrium from women with endometriosis when compared with women without the disease in both the proliferative and secretory phases. HIF1A is known to be stabilized by STAT3 and IL-6. Our immunohistochemistry results show abundant HIF1A expression within the eutopic endometrial epithelial cells of women with endometriosis. Furthermore, pSTAT3 and HIF1A proteins are co-localized in endometriosis. This aberrant activation of pSTAT3 and HIF1A is confirmed by sequential analysis of eutopic endometrium using a baboon animal model of induced endometriosis. Lastly, we confirmed this IL-6 induction of both STAT3 phosphorylation and HIF1A mRNA expression in Ishikawa human endometrial adenocarcinoma cell line.

LIMITATIONS, REASONS FOR CAUTION

Ishikawa cancer cell line was used to study a benign disease. The peritoneal fluid contains various inflammatory cytokines in addition to IL-6 and so it is possible that other cytokines may affect the activity and expression of STAT3 signaling molecules.

WIDER IMPLICATIONS OF THE FINDINGS

Our results imply that aberrant activation of STAT3 signaling plays an important role in the pathogenesis of endometriosis. Our findings could progress in our understanding of the etiology and pathophysiology of endometriosis and potential therapeutic interventions by targeted pharmacological.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by NIH R01 HD067721 (to S.L.Y and B.A.L) and NIH R01 HD057873 and American Cancer Society Research Grant RSG-12-084-01-TBG (to J.-W.J.). There are no conflicts of interest.