Ectopic Endometriotic Stromal Cells Research Articles

IGF2BP3 promotes glutamine metabolism of endometriosis by interacting with UCA1 to enhances the mRNA stability of GLS1

BackgroundInsulin like growth factor II mRNA binding protein 3 (IGF2BP3) has been implicated in numerous inflammatory and cancerous conditions. However, its precise molecular mechanisms in endometriosis (EMs) remains unclear. The aim of this study is to examine the influence of IGF2BP3 on the occurrence and progression of EMs and to elucidate its underlying molecular mechanism.MethodsEfects of IGF2BP3 on endometriosis were confrmed in vitro and in vivo. Based on bioinformatics analysis, RNA immunoprecipitation (RIP), RNA pull-down assays and Fluorescent in situ hybridization (FISH) were used to show the association between IGF2BP3 and UCA1. Single-cell spatial transcriptomics analysis shows the expression distribution of glutaminase 1 (GLS1) mRNA in EMs. Study the effect on glutamine metabolism after ectopic endometriotic stromal cells (eESCs) were transfected with Sh-IGF2BP3 and Sh-UCA1 lentivirus.ResultsImmunohistochemical staining have revealed that IGF2BP3 was upregulated in ectopic endometriotic lesions (EC) compared to normal endometrial tissues (EN). The proliferation and migration ability of eESCs were greatly reduced by downregulating IGF2BP3. Additionally, IGF2BP3 has been observed to interact with urothelial carcinoma associated 1 (UCA1), leading to increased stability of GLS1 mRNA and subsequently enhancing glutamine metabolism. Results also demonstrated that IGF2BP3 directly interacts with the 3’ UTR region of GLS1 mRNA, influencing its expression and stability. Furthermore, UCA1 was able to bind with c-MYC protein, stabilizing c-MYC mRNA and consequently enhancing GLS1 expression through transcriptional promotion.ConclusionThese discoveries underscored the critical involvement of IGF2BP3 in the elevation and stability of GLS1 mRNA in the context of glutamine metabolism by interacting with UCA1 in EMs. The implications of our study extended to the identification of possible therapeutic targets for individuals with EMs.

Targeting YAP1 ameliorates progesterone resistance in endometriosis

Does YAP1 inhibition alleviate progesterone resistance in endometriosis? YAP1 inhibition reduces progesterone resistance in vitro and in vivo. Progesterone resistance not only causes treatment failure for endometriosis but also inhibits eutopic endometrial cell proliferation, dysregulates decidualization, and reduces the success rates of pregnancy. Hippo/yes-associated protein 1 (YAP1) signaling pathway plays an important role in the pathogenesis of endometriosis. Paraffin-embedded tissues containing paired endometriotic and endometrial specimens (n = 42) and serum samples isolated from normal controls (n = 15) or endometriotic patients with (n = 25) or without (n = 21) prior dienogest treatment were analyzed. A mouse model of endometriosis was also used to evaluate the effects of YAP1 inhibition on progesterone resistance. Primary endometriotic and endometrial stromal cells treated with YAP1 inhibitor or miR-21 mimic/inhibitor were used for the in vitro studies including decidualization induction, chromatin immunoprecipitation (ChIP), and RNA immunoprecipitation. Tissue specimens and serum from human and mouse were used for immunohistochemistry staining, exosome isolation, and microRNA (miRNA) quantification, respectively. Herein, we report, by using ChIP-PCR and RNA-IP, that YAP1 inhibits progesterone receptor (PGR) expression through upregulation of miR-21-5p. Upregulation of miR-21-5p not only reduces PGR expression but also inhibits endometrial stromal cell decidualization. Indeed, levels of YAP1 and miR-21-5p are inversely correlated with the level of PGR in human endometrial samples. In contrast, knockdown of YAP1 or treatment with verteporfin (VP), a YAP1 inhibitor, reduces miR-21-5p expression, thus leading to an increase in PGR expression in ectopic endometriotic stromal cells. In the mouse model of endometriosis, treatment with VP increases PGR expression and enhances decidualization. More importantly, VP synergistically increases the treatment effect of progestin in causing the regression of endometriotic lesions and improves the decidualization capability of the endometrium. Interestingly, treatment with dienogest, a synthetic progestin, reduces YAP1 and miR-21-5p expression in human cells and in the mouse model of endometriosis. Patients who received dienogest treatment for 6 months show a significant decrease in serum extracellular vesicle-associated miR-21-5p level. A public dataset (GSE51981) containing a large cohort of endometriotic tissues is available from the Gene Expression Omnibus (GEO). A large cohort of clinical samples is needed to verify the current diagnostic value of miR-21-5p in future studies. The reciprocal regulation of YAP1 and PGR suggests that combined YAP1 inhibitor and progestin may be a better therapeutic approach for treating endometriosis. This study was supported by the Ministry of Science and Technology, Taiwan (MOST-111-2636-B-006-012, MOST-111-2314-B-006-075-MY3, and MOST-106-2320-B-006-072-MY3). The authors have no conflict of interest to disclose.

FTO-dependent N(6)-Methyladenosine regulates the progression of endometriosis via the ATG5/PKM2 Axis

N6-methyladenosine (m6A), the most abundant internal modification on mRNAs in eukaryotes, plays a role in endometriosis (EMs). However, the underlying mechanism remains largely unclear. Here, we found that FTO is downregulated in EMs; and plays an important role in regulating glycolysis, proliferation, and metastasis of ectopic endometriotic stromal cells (EESCs) by targeting ATG5. We demonstrated that FTO promotes ATG5 expression in a m6A-dependent manner, and further studies revealed that PKM2 is a target of ATG5. Upon FTO overexpression, increased ATG5 protein expression at low m6A levels inhibited the expression of PKM2, thereby reducing the glycolysis level of EESCs. In addition, we demonstrated through in vitro functional experiments that FTO regulates glycolysis, proliferation, and metastasis of EESCs through the ATG5/PKM2 axis. In conclusion, these findings reveal the functional importance of the m6A methylation mechanism of FTO in regulating the development of EMs, which expands our understanding of this interaction, which is crucial for the development of therapeutic strategies for EMs.

Epidermal growth factor promotes stromal cells migration and invasion via up-regulation of hyaluronate synthase 2 and hyaluronan in endometriosis

To investigate the role(s) of hyaluronan synthase 2 (HAS2) and hyaluronan in disease progression of endometriosis and epidermal growth factor (EGF)-induced motility changes of endometriotic cells. A case-control experimental study and invitro primary cell culture study. University hospital-affiliated research centers. A total of 21 women with stage I/II endometriosis, 33 women with stage III/IV endometriosis with endometrioma, and 32 women without endometriosis were included in our study. Serum, eutopic endometrial tissues, and/or ectopic endometriotic tissues were collected. Primary eutopic endometrial stromal cells (EuESCs) and ectopic ovarian endometriotic stromal cells (OvESCs) were isolated and cultured from women with ovarian endometrioma, and then treated with or without EGF. The concentrations of EGF and hyaluronan in serum were analyzed by enzyme-linked immunosorbent assay. The expressions and localizations of EGF receptor (EGFR), phosphorylated-(p)EGFR, HAS2, and hyaluronan receptor CD44 in tissues were examined by immunohistochemistry. The mRNA and protein levels of HAS2 in EuESCs and OvESCs were examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot, respectively, and the concentrations of hyaluronan in conditioned medium were examined by enzyme-linked immunosorbent assay (ELISA). Cell motility was evaluated by transwell migration/invasion assays. Serum EGF and hyaluronan concentrations were higher in women with stage III/IV endometriosis than in women with stage I/II or without endometriosis. EGFR, pEGFR, HAS2, and CD44 were immunolocalized in eutopic endometrium and ectopic endometriotic lesions, and the expressions of pEGFR and HAS2 were elevated in ectopic endometriotic lesions compared to eutopic endometrium. Treatment with EGF upregulated HAS2 and hyaluronan expression as well as cell migration and invasion in both EuESCs and OvESCs, and pharmaceutical blocking of EGFR abolished these effects. In addition, knockdown of HAS2 by small interfering RNA attenuated both basal and EGF-induced hyaluronan expression and cell motility changes. Notably, ERK1/2 and AKT signaling pathways were shown to be downstream of EGF in regulating HAS2 and hyaluronan expression as well as cell migration and invasion. EGF increased the expression of endometriosis-associated hyaluronan and its synthase HAS2, both of which mediated EGF-induced stromal cell migration and invasion in women with endometriosis.

Lipoxin A4 Suppresses IL-1β-Induced Cyclooxygenase-2 Expression Through Inhibition of p38 MAPk Activation in Endometriosis

Endometriosis is an inflammation-dependent gynecologic disorder. Increased cyclooxygenase-2 (COX-2) expression plays an important role in the development and progression of endometriosis. Lipoxin A4 (LXA4) is an endogenous anti-inflammation lipid and showed inhibitory effects on the development of endometriosis; however, the mechanism remains unclear. In this study, the overexpression of COX-2 was observed in ectopic endometrium of endometriosis patients compared to the normal endometrium of controls. Lipoxin A4 efficiently suppressed IL-1β-induced COX-2 protein expression in ectopic endometriotic stromal cells (ESCs) via its receptor, formyl peptide receptor 2/lipoxin A4 receptor (FPR2/ALX). Antagonism of FPR2/ALX eliminated the inhibitory effect by LXA4. IL-1β induced the activation of mitogen-activated protein kinases (MAPKs), which can promote the expression of COX-2. Pretreatment of ESCs with LXA4 inhibited the phosphorylation of p38 MAPK induced by IL-1β. These findings suggest that inflammation and MAPKs pathways respond for the abnormal expression of COX-2, which can elucidate the pathophysiology of endometriosis. Moreover, LXA4 suppressed IL-1β-induced COX-2 expression through inhibiting the p38 MAPK signaling protein. This research contributes for better understanding of the cellular and biological events of inflammation and anti-inflammation-mediated regulation in endometriosis.

Ginsenoside Rg3 attenuates endometriosis by inhibiting the viability of human ectopic endometrial stromal cells through the nuclear factor-kappaB signaling pathway

ObjectiveTo investigate the effects of ginsenoside Rg3 on human ectopic endometriotic stromal cells in vitro. Materials and methodsEctopic endometrial tissue specimens were obtained from 6 female patients with ovarian endometriosis who underwent laparoscopic surgical procedures. Endometrial stromal cells derived from isolated ectopic endometriotic lesions were cultured, and the purity and homogeneity of cells were verified by Immunocytochemistry. The effect of Rg3 on cell proliferation was detected by Cell Counting Kit-8 (CCK8). After treatment with Rg3, the protein expression of NF-κB p65 subunit, VEGF, and caspases3 were measured by western blot analysis. Meanwhile, the mRNA expression of NF-κB p65 subunit was determined by Quantitative real-time polymerase chain reaction (RT-PCR). ResultsRg3 inhibited the proliferation of ectopic endometriotic cells in a time- and dose-dependent manner. The treatment with Rg3 significantly diminished the level of NF-κB p65 subunit as well as TNF-α induced nuclear translocation of NF-κB p65 subunit in ectopic endometriotic cells. Moreover, Rg3 upregulated the expression of caspases3 but suppressed the expression of VEGF. ConclusionOur results indicate that Ginsenoside Rg3 suppresses endometriosis by reducing the viability of human ectopic endometrial stromal cells involving the nuclear factor-kappaB signaling pathway in vitro.

Induction of Pyruvate Dehydrogenase Kinase 1 by Hypoxia Alters Cellular Metabolism and Inhibits Apoptosis in Endometriotic Stromal Cells.

Endometriosis is a common gynecological disease, which is defined as the growth of endometrial tissues outside the uterine cavity. It often causes dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility in reproductive-age women. However, the pathogenesis of endometriosis remains largely unclear. Since our previous study revealed that ectopic endometriotic stromal cells experience greater hypoxic stress than their eutopic counterparts, we aim to investigate whether the metabolic properties are changed in the ectopic endometriotic stromal cell when compared to its eutopic counterpart. Here, we found the expression of pyruvate dehydrogenase kinase 1 (PDK1), a critical enzyme in regulating glucose metabolism, was increased in ectopic stromal cells. Molecular characterization reveals that overexpression of PDK1 is induced by hypoxia through transcriptional regulation. Upregulation of PDK1 in ectopic endometriotic stromal cells was accompanied by increases in lactate production and oxygen consumption rate when compared to eutopic endometrial stromal cells. Furthermore, our data showed that inhibition of PDK1 activity by treatment with dichloroacetate inhibits the lactate production and oxygen consumption rate of ectopic stromal cells. In addition, hypoxia-induced PDK1 expression prevented cells from H2O2- and low nutrient-induced cell death. These data indicate that ectopic endometriotic cells may adapt to hypoxic microenvironment via upregulating PDK1 and reprogramming metabolism, which provides a survival advantage in the hostile peritoneal microenvironment.

Suppression of COUP-TFII upregulates angiogenin and promotes angiogenesis in endometriosis.

How does hypoxia-mediated downregulation of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) promote angiogenesis in endometriosis? Suppression of COUP-TFII by hypoxia stimulates angiogenesis through induction of angiogenin (ANG). The level of COUP-TFII is downregulated in endometriotic tissues, and downregulation of COUP-TFII contributes to the development of endometriosis. Twenty-seven patients of reproductive age with endometriosis were recruited in this study. Eutopic endometrial and ectopic endometriotic stromal cells were isolated, cultured and subjected to various treatments. Microarray hybridization, quantitative RT-PCR, and Western blot were used to detect gene expression in normal and endometriotic samples. A luciferase reporter assay and chromatin immunoprecipitation in normoxia- or hypoxia-treated primary cultures of human endometrial stromal cells were performed. Tube formation analysis was performed using primary human umbilical vein endothelial cells (HUVECs). Protein level of COUP-TFII was downregulated by hypoxia (P < 0.05, normoxia versus hypoxia). Loss of COUP-TFII increased the angiogenic capacity of endometrial stromal cells (P < 0.05, COUP-TFII knockdown versus knockdown control). A novel COUP-TFII target gene, ANG, was identified through microarray analysis. Chromatin immunoprecipitation and promoter activity assays demonstrated that the ANG promoter was bound and suppressed by COUP-TFII (P < 0.05, COUP-TFII overexpression versus empty vector). The levels of ANG mRNA and protein were elevated in ectopic endometriotic stromal cells and negatively correlated with COUP-TFII (P < 0.05, endometrial versus endometriotic tissues/stromal cells). Both knockdown and forced-expression of COUP-TFII further demonstrated that ANG expression and ANG-mediated angiogenic activity were negatively regulated by COUP-TFII (P < 0.05, COUP-TFII knockdown versus knockdown control, and COUP-TFII overexpression versus empty vector). This study was conducted in primary human endometrial stromal cell cultures and HUVECs, therefore, may not fully reflect the situation in vivo. The raw data were submitted to Gene Expression Omnibus (GSE107469). This is the first study to highlight that the aberrant expression of ANG in endometriotic lesions is mediated by hypoxia-suppressed COUP-TFII expression, which reveals an as yet unidentified molecular pathogenesis of endometriosis. This work was supported by research grants (MOST 105-2314-B-006-059-MY3 to M.H.W. and MOST 104-2320-B-006-036-MY3 to S.J.T.) from the Ministry of Science and Technology, Taiwan. The authors declare that there is no conflict of interest.

Role of Brain-Derived Neurotrophic Factor in Endometriosis Pain.

Brain-derived neurotrophic factor (BDNF) is a regulator for the formation and maintenance of chronic pain in various chronic disorders and has been shown to increase in the serum of women with endometriosis. However, BDNF expression in the peritoneal fluid (PF) and ectopic lesions and its role in endometriosis pain remain unclear. Thus, this study aims to determine the BDNF concentrations in serum and PFs and BDNF expression levels in ectopic lesions and endometriotic stromal cells (ESCs) of women with endometriosis (n = 60). The obtained results were then compared with those of women without endometriosis (n = 38). Brain-derived neurotrophic factor concentrations in serum and PF, as well as the BDNF expression levels in ectopic lesions and endometriotic cells, were evaluated through enzyme-linked immunosorbent assay, immunohistochemical staining, quantitative real-time polymerase chain reaction, and Western blot analysis. As a result, BDNF concentrations in serum and PF were significantly higher in women with endometriosis with pain (2284.3 ± 51.5 pg/mL, n = 23; 58.8 ± 6.4 pg/mL, n = 16) than in women with endometriosis without pain (1999.8 ± 61.1 pg/mL, n = 37; 31.7 ± 2.9 pg/mL, n = 25; P < .01). Moreover, BDNF messenger RNA (mRNA) expression levels in ectopic lesions (8.97 ± 1.44, n = 29) were significantly higher than eutopic (0.97 ± 0.14, n = 16; P < .01) and control endometrium (1.23 ± 0.19, n = 18; P < .01) and were correlated with endometriosis pain ( P < .05). Furthermore, increased BDNF mRNA and protein expression levels in ESCs induced by estradiol or interleukin 1β were removed using a phosphorylated extracellular-regulated protein kinase 1/2 inhibitor. These results suggest that BDNF may play an important role in the pathogenesis of endometriosis pain.

Wenshen Xiaozheng Tang induces apoptosis and inhibits migration of ectopic endometriotic stromal cells

Ethnopharmacological relevanceWenshen Xiaozheng Tang (WXT), a traditional Chinese medicine prescription, exerted a good therapeutic effect on endometriosis. However, the underlying mechanism is unclear. In the present study, we sought to evaluate the effect of WXT on the proliferation and migration of ectopic endometriotic stromal cells and explore the potential molecular mechanism. Materials and methodsPrimary stromal cells derived from ectopic endometriotic lesions of patients with endometriosis were isolated and cultured. The inhibition effect of WXT on cell proliferation was determined by MTT. Apoptosis of ectopic endometriotic cells treated with WXT was analyzed with Annexin V-FITC/7-AAD staining. The activation of caspases was detected by western blot analysis. The influence of WXT on migration of ectopic endometriotic cells was measured by scratch wound healing assay and Transwell assay. The DNA binding activity of NF-κB and the expression of nuclear p65 protein were determined by electrophoretic mobility shift assay and western blot analysis, respectively. The impact of WXT on the expression of NF-κB regulated gene products involved in apoptosis and migration was determined by western blot analysis. ResultsWXT inhibited the proliferation of ectopic endometriotic cells in a time- and dose-dependent manner. In addition, WXT treatment resulted in significant induction of apoptosis through the activation of caspases and inhibition of migration in ectopic endometriotic cells. WXT notably suppressed constitutive NF-κB-DNA-binding activity as well as TNF-α induced nuclear translocation of NF-κB p65 subunit in ectopic endometriotic cells. Moreover, WXT diminished the expression of NF-κB regulated gene products involved in apoptosis and migration, including c-IAP1, c-IAP2, XIAP, survivin, Mcl-1, COX-2 and MMP-9. ConclusionsOur results indicate that WXT induces apoptosis and inhibits migration of ectopic endometriotic stromal cells.

Deep Quantitative Proteomics Reveals Extensive Metabolic Reprogramming and Cancer-Like Changes of Ectopic Endometriotic Stromal Cells

Endometriosis is a prevalent health condition in women of reproductive age characterized by ectopic growth of endometrial-like tissue in the extrauterine environment. Thorough understanding of the molecular mechanisms underlying the disease is still incomplete. We dissected eutopic and ectopic endometrial primary stromal cell proteomes to a depth of nearly 6900 proteins using quantitative mass spectrometry with a spike-in SILAC standard. Acquired data revealed metabolic reprogramming of ectopic stromal cells with extensive upregulation of glycolysis and downregulation of oxidative respiration, a widespread metabolic phenotype known as the Warburg effect and previously described in many cancers. These changes in metabolism are additionally accompanied by attenuated aerobic respiration of ectopic endometrial stromal cells as measured by live-cell oximetry and by altered mRNA levels of respective enzyme complexes. Our results additionally highlight other molecular changes of ectopic endometriotic stromal cells indicating reduced apoptotic potential, increased cellular invasiveness and adhesiveness, and altered immune function. Altogether, these comprehensive proteomics data refine the current understanding of endometriosis pathogenesis and present new avenues for therapies.

Effects of the hypoxia-inducible factor-1 inhibitor echinomycin on vascular endothelial growth factor production and apoptosis in human ectopic endometriotic stromal cells

Recent evidence points to a possible role for hypoxia-inducible factor (HIF)-1 in the pathogenesis and development of endometriosis. The objectives of this study were to investigate the critical role of HIF-1 in endometriosis and the effect of the HIF-1 inhibitor echinomycin on human ectopic endometriotic stromal cells (eESCs). Ectopic endometriotic tissues were obtained from 20 patients, who received an operation for ovarian endometriomas. We examined vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) production, HIF-1 expression, cell proliferation and apoptosis of eESCs. Cobalt chloride (CoCl2) significantly induced expression of HIF-1α protein and VEGF production in a time-dependent manner in eESCs, but reduced SDF-1 production. VEGF production was significantly suppressed by treatment of 100 nM echinomycin without causing cell toxicity, but 0.1–10 nM echinomycin or 100 nM progestin had no significant effect. SDF-1 production was not affected by echinomycin treatment at any dose. Echinomycin inhibited cell proliferation and induced apoptotic cell death of the eESCs, and significantly inhibited expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL. Echinomycin inhibits VEGF production and induces apoptosis of eESCs by suppression of Bcl-2 and Bcl-xL. These findings suggest the unique therapeutic potential for echinomycin as an inhibitor of HIF-1 activation for endometriosis treatment.

Coordination of AUF1 and miR-148a destabilizes DNA methyltransferase 1 mRNA under hypoxia in endometriosis.

DNA methylation is regulated by hypoxia in endometriosis. Hypoxia causes global hypomethylation through AU-rich element binding factor 1 (AUF1)/microRNA-148a (miR-148a)-mediated destabilization of DNA methyltransferase 1 (DNMT1) mRNA. Eutopic endometrial and ectopic endometriotic stromal cells have the same genetic background, but differ in several cellular and molecular responses. Both hypoxia and DNA methylation regulate several genes involved in the development of endometriosis. This laboratory study included 15 patients of reproductive age with endometriosis or normal menstrual cycles. Paired endometrial and endometriotic tissues were collected for assaying the levels of DNMT1, 3a and 3b using quantitative RT-PCR, western blot and immunohistochemical (IHC) staining. Primary cultured endometrial stromal cells maintained in normoxia/hypoxia (1% O2) or treated with hypoxia-mimetic compounds were also assayed. The levels of DNA 5-methylcytosine were assayed by using IHC in clinical specimens and murine tissues, and by ELISA in cultured stromal cells. The 3'-untranslated region reporter assay was used to evaluate the effect of hypoxia, microRNAs (miRNAs) and human antigen R (HuR)/AUF1 on DNMT1 mRNA stability. RNA immunoprecipitation was used to assess the interaction of HuR/AUF1 and miR-148a/DNMT1 mRNA under hypoxia. Finally, a transplant-induced mouse model of endometriosis using 20 mice was used to elucidate the alteration of Dnmt1 levels and DNA methylation in the endometriotic tissues. Levels of DNMT1 mRNA and protein and 5-methylcytosine were lower in the ectopic stromal cells (P < 0.05) than in the eutopic cells. Treatment with hypoxia and its mimetic compounds recapitulated the reduced levels of DNMT1 and 5-methylcytosine levels (P < 0.05 versus control). Hypoxia treatment destabilized DNMT1 mRNA through recruitment of miR-148a and AUF1. Mutations introduced to the miR-148a targeting site or AU-rich element (ARE) restored the hypoxia-suppressed DNMT1 3'-untranslated region (3'-UTR) reporter activity (P < 0.05 versus control). Levels of proteins of three hypermethylated genes in endometrial stroma cells, GATA6, HOXA3 and SLC16A5, were elevated after 72 h of hypoxia treatment (P < 0.05 versus control). Finally, a transplant-induced model of endometriosis demonstrated the down-regulation of DNMT1 and a decrease in 5-methylcytosine in the endometriotic tissues (P < 0.05, eutopic versus ectopic). Primary human cell cultures and a murine model were used in this study, and thus the results may not fully represent the situation in vivo. This is the first study to elucidate how microenvironmental hypoxia links to the epigenetic effects of DNA methylation in the endometriosis, and to delineate the molecular mechanism of hypoxia-coordinated AUF1/miR-148a interaction and recruitment to DNMT1 mRNA during the pathogenesis of endometriosis. The development of future therapeutics in endometriosis may aim at disrupting this specific interaction and eventually restore the epigenetic regulation. This work was supported by the National Science Council of Taiwan (NSC101-2320-B-006-030-MY3). The author declares that there are no conflicts of interest.

Metformin regulates stromal-epithelial cells communication via Wnt2/β-catenin signaling in endometriosis

In previous studies, we found that endometriotic stromal cells lose the ability to regulate cell survival signaling in endometriotic epithelial cells. Here, we invested the effect of Metformin on the stromal-epithelial cells crosstalk in endometriosis and explored the pathway that might be involved. We found that ectopic endometriotic stromal cells (ESC) expressed and secreted higher Wnt2 protein compared with normal endometrial stromal cells (NSC). Conditioned medium (CM) from ESC supplemented with Wnt2 antibody significantly inhibited the growth of normal endometrial epithelial cells (NEC), while CM from ESC per se showed no significant effect on the growth of NEC. Metformin decreased the expression and secretion of Wnt2 in ESC. CM from Metformin-pretreated ESC significantly inhibited the growth of NEC. In conclusion, Wnt2/β-catenin signaling was involved in stromal-epithelial cells interaction in endometriosis. Metformin might regulate the stroma-epithelium communication via Wnt2-mediated signaling in endometriosis.

Drospirenone induces decidualization in human eutopic endometrial stromal cells and reduces DNA synthesis of human endometriotic stromal cells

To investigate the invitro effect of drospirenone on human eutopic endometrial (EuSC) and ectopic endometriotic stromal cells (EcSC). Comparative and laboratory study. The experimental procedures were approved by the Institutional Review Board of the University of Tokyo (registration no. 0324-4). University research laboratory. Eight patients undergoing hysterectomy for benign gynecologic disease and 19 patients undergoing cystectomy or adnectomy for endometriosis. EuSC and EcSC were treated with drospirenone. For the analysis of decidualization of EuSC, cells were observed using microscopy, and the production of PRL was measured using enzyme immunoassay. For the analysis of DNA synthesis of EcSC, 5-bromo-2'-deoxyuridine incorporation was measured by ELISA. Cells in apoptosis were detected and measured by flow cytometry. Drospirenone induced decidualization in EuSC, and the induction was negated by RU486. Drospirenone reduced DNA synthesis on EcSC, and this reduction was negated by RU486 or P receptor silencing, but not by aldosterone or mineralocorticoid receptor silencing. Drospirenone did not cause EcSC to undergo apoptosis. Our study demonstrates the direct effects of drospirenone: decidualization of EuSC and reduced DNA synthesis of EcSC, but it does not cause EsSC apoptosis.

Overexpression of lysine-specific demethylase 1 in ovarian endometriomas and its inhibition reduces cellular proliferation, cell cycle progression, and invasiveness

To investigate whether lysine-specific demethylase 1 (LSD1) is aberrantly expressed in endometriomas and whether treatment with tranylcypromine, an LSD1 inhibitor, has any effect on cell viability, cell cycle, and invasiveness. Laboratory study using human tissues. Academic hospital. Forty-two ectopic endometrial tissue samples, their homologue eutopic endometrial tissue samples, and 70 control endometrial tissue samples. Immunohistochemistry analysis of LSD1 of all human tissue samples, and Western blot analysis, quantitative real-time reverse-transcription polymerase chain reaction analysis, cell viability assay, cell cycle analysis, and invasion assay of eutopic and ectopic endometriotic stromal cells and normal endometrial stromal cells. Immunostaining levels of LSD1, gene and protein expression levels, cell viability, cell cycles, and invasiveness. The expression of the LSD1 gene and protein in endometriosis was elevated. Treatment of endometriotic stromal cells with tranylcypromine statistically significantly reduced the cellular proliferation, cell cycle progression, and invasiveness. Because DNA and histones are intimately intertwined and work in concert in transcription regulation, conceivably histone demethylation activity of LSD1 could be wide ranging. The inhibition of LSD1 activity by tranylcypromine and the resultant inhibition of proliferation, cell cycle progression, and invasiveness suggest that LSD1 may be a candidate therapeutic target for endometriosis.

Hypoxia-Induced MicroRNA-20a Expression Increases ERK Phosphorylation and Angiogenic Gene Expression in Endometriotic Stromal Cells

Aberrant activation of MAPK has been implicated to play important roles in pathological processes of endometriosis. However, how MAPK are constitutively activated in endometriotic tissues remains largely unknown. microRNA are small noncoding RNA that regulate the stability or translational efficiency of target mRNA by interacting with the 3' untranslated region. Thus, miRNA are thought to be modulators of the transcriptional response, fine-tuning gene expression. The aim of this study was to evaluate the functional roles of microRNA-20a (miR20a) in MAPK activation and the pathogenesis of endometriosis. miR20a expression was analyzed in nonpaired (endometrium = 17; endometriosis = 37) and paired (n = 12) endometriotic tissues by quantitative RT-PCR. Overexpression of miR20a in eutopic endometrial stromal cells or inhibition of miR20a in ectopic endometriotic stromal cells was used to evaluate its impact on ERK phosphorylation and subsequently angiogenesis- and proliferation-related gene expression. Levels of miR20a were up-regulated in endometriotic stromal cells. Elevation of miR20a was up-regulated by hypoxia inducible factor-1α. The up-regulation of miR20a causes the down-regulation of dual-specificity phosphatase-2, which leads to prolonged ERK phosphorylation and an increase in the expression of several angiogenic genes. Furthermore, the up-regulation of miR20a enhances the prostaglandin E(2)-induced expression of fibroblast growth factor-9, a potent mitogen that stimulates both endothelial and endometrial cell proliferation. Our findings provide the novel mechanism that not only functionally links together hypoxic stress, miR20a expression, aberrant ERK phosphorylation, and angiogenesis but also demonstrates that miR20a is an important modulator in the development of endometriosis.

The ferroimmunomodulatory role of ectopic endometriotic stromal cells in ovarian endometriosis

To understand the role of ectopic endometriotic stromal cells in ovarian endometriosis (OEM) and the associated risks for infertility and carcinogenesis. Analyses of secreted proteins and gene expression using immortalized eutopic/ectopic endometrial(-otic) stromal cells from OEM. University. Women with and without OEM. Samples of endometrial(-otic) tissue from women with or without OEM. Immunohistochemical analysis of oxidative stress in OEM, gene expression profiles, and the identification of secreted proteins by mass spectrometry in immortalized endometrial(-otic) stromal cells. 4-Hydroxy-2-nonenal-modified proteins and carboxymethyllysine were abundant in the stroma, rather than epithelia, of OEM patients, indicating the presence of oxidative stress. Immortalized ectopic endometriotic stromal cells exhibited high IRP1/IRP2/HIF-1β expression and contained lower amounts of iron and copper than their eutopic counterparts. Expression profiles, in combination with protein identification, revealed that complement component 3 (C3) and pentraxin-3 (PTX3) are the major proteins secreted from immortalized ectopic endometriotic stromal cells. Complement-3/PTX3 promoted the secretion of various cytokines by THP1 macrophage cells and thus supported M1 differentiation. Immortalized ectopic endometriotic stromal cells in OEM predominantly secrete C3 and PTX3 and exhibit a differential regulation of iron metabolism.

Estrogen receptor expression affected by hypoxia inducible factor-1α in stromal cells from patients with endometriosis

ObjectiveEndometriosis is an estrogen-dependent disease. The aim of this study was to evaluate the different expression of estrogen receptors (ER) and its relation to hypoxia inducible factor-1α (HIF-1α) in stromal cells from women with endometriosis. Materials and MethodsPaired eutopic endometrial and ectopic endometriotic stromal cells were isolated from women with endometriosis while they underwent laparoscopy. The expression of ERα and ERβ was measured by reverse transcription-polymerase chain reaction and Western blot. Regulation of ER expression was evaluated by HIF-1α knockdown via short interference RNA. ResultsThe expression of ERβ was significantly increased in ectopic stromal cells. Treatment of endometrial stromal cells with hypoxia induced ERβ expression. Knockdown of HIF-1α abolished hypoxia-induced ERβ expression and increased ERα expression. ConclusionThe expression of ERβ is regulated by hypoxia. Results of this study will provide important information in the involvement of hypoxia factors in mediating estrogen action via different ER expression in endometriosis.

Curcumin Attenuates TNF‐α‐induced Expression of Intercellular Adhesion Molecule‐1, Vascular Cell Adhesion Molecule‐1 and Proinflammatory Cytokines in Human Endometriotic Stromal Cells

Curcumin, a naturally occurring polyphenolic compound from Curcuma longa, has long been used in folk medicine as an antiinflammatory remedy in Asian countries. Endometriosis is a chronic gynecological inflammatory disorder in which immune system deregulation may play a role in its initiation and progression. A number of mediators, including cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1); proinflammatory cytokines such as tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-6 and IL-8; and chemokines such as monocyte chemotactic protein-1 (MCP-1), play key roles in the pathogenesis of endometriosis. The aim of our study was to explore the effect of curcumin on the expression of these critical molecules in human ectopic endometriotic stromal cells isolated from women with endometriosis. Endometriotic stromal cells treated with curcumin showed marked suppression of TNF-α-induced mRNA expression of ICAM-1 and VCAM-1. Curcumin treatment also significantly decreased the TNF-α-induced cell surface and total protein expression of ICAM-1 and VCAM-1 in a dose-dependent manner. In addition, treatment of endometriotic stromal cells with curcumin markedly inhibited TNF-α-induced secretion of IL-6, IL-8 and MCP-1. Furthermore, curcumin inhibited the activation of transcription factor NF-κB, a key regulator of inflammation, in human endometriotic stromal cells. These findings suggest that curcumin may have potential therapeutic uses in the prevention and treatment of endometriosis.