Endometriotic Cyst Stromal Cells Research Articles

Dienogest attenuates STAT3 activation in ovarian endometriotic cysts

ObjectiveRecent studies have suggested that endometriosis could be the result of excessive activation of signal transducer and activator of transcription 3 (STAT3), which is associated with the regulation of essential cellular mechanisms such as proliferation, invasion, and apoptosis. That finding implies that regulating STAT3 activation could play a key role in treating endometriosis. In the present study, we aimed to evaluate whether the anti-endometriotic effects of dienogest is mediated by the regulation of STAT3 activation. Study designSTAT3 activation was evaluated in normal endometrial and ovarian endometriotic tissues obtained from patients with/without preoperative dienogest treatment. A subsequent in vitro analysis with endometriotic cyst stromal cells (ECSCs) was used to confirm the direct influence of dienogest in STAT3 activation. ResultSTAT3 activation is significantly higher in endometriotic tissues from non-treated patients than in normal endometrial tissues, and that difference is reversed by preoperative administration of dienogest. Similarly, the inhibitory effects of dienogest on STAT3 activation are demonstrated by in vitro results showing that dienogest treatment significantly inhibits IL-6-stimulated STAT3 activation in cultured ECSCs. That inhibition was accompanied by decreased expression of proliferative (PCNA), invasive (MMP-2), and anti-apoptotic (BCL-2) proteins. Furthermore, downregulating STAT3 activity with siRNA decreased PCNA, MMP-2, and BCL-2 expression in IL-6-treated ECSCs. ConclusionDienogest inhibits STAT3 activation in ECSCs, which affects their proliferation, invasiveness, and apoptosis.

Effect of PLGA Nanoparticle-Mediated Delivery of miRNA 503 on The Apoptosis of Ovarian Endometriosis Cells.

One of the challenges in gene therapy is the transfer of the gene to the target cell. MicroRNAs (miRNAs) regulate gene expression after transcription by binding directly to the messenger and play a vital role in cell behaviors and the pathogenesis of some diseases. This study was aimed at developing poly (lactic-co-glycolic acid) (PLGA)- based nanoparticles (NPs) for gene delivery to endometriotic cyst stromal cells (ECSCs). In this experimental study, endometriosis cells were isolated from women with severe endometriosis (DIE) and digested by the enzymatic method (40 μg/ml DNAase I and 300 μg/ml collagenase type 3). PLGA-based NPs were synthesized and characterized. The size of sole PLGA NPs and PLGA/miRNA were 60 ± 4 nm and 70 ± 5.1 nm respectively. Poly lactic-co-glycolic-based NPs were used as vector carriers for miRNA 503 transfection in endometriosis cells. The cells were divided into the five groups of control and four doses (25, 50, 75, and 100 μm) of miRNA 503/PLGA at 12, 24, 48, and 72 hours. Viability and apoptosis were evaluated by the MTT assay and Annexin Kits. Data were analyzed by one-way analysis of variance. The results show that the size of PLGA/miRNA complex with dynamic light scattering (DLS) was 70 ± 5.1 nm and zeta potential values of the PLGA/PEI/miRNA complexes were 27.9 mV. Based on the MTT assay results, the optimal dose of miRNA 503/PLGA was 75 μm, at which the viability of ECSCs was 52.6% ± 1.2 (P≤0.001), and the optimal time was 48 hours. The apoptotic rates of ECSCs treated with PLGA/miRNA503 (34.75 ± 4.9%) were significantly higher than those of ECSCs treated with PLGA alone (3.35 ± 2.58%, P≤0.01). Cell death increased with increasing the concentration of miRNA; thus, it can be suggested as a treatment for endometriosis.

Inhibition of the NLRP3 inflammasome by progesterone is attenuated by abnormal autophagy induction in endometriotic cyst stromal cells: implications for endometriosis.

The NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is a cytosolic multi-protein complex that induces inflammation and is known to be regulated negatively by autophagy. Previous studies reported an abnormal induction of autophagy linked to progesterone resistance in human endometriotic cells. Therefore, an aberrant autophagy induction response to progesterone might contribute to the altered inflammatory response observed in endometriotic tissues. To evaluate this hypothesis, we elucidate whether regulation of the NLRP3 inflammasome by ovarian steroids is mediated by autophagy in human endometrial stromal cells (normal endometrial stromal cells (NESCs)) from patients with uterine leiomyoma (presumed normal) and whether abnormal autophagy induction in endometriotic cyst stromal cells (ECSCs) affects NLRP3 inflammasome-induced interleukin-1β (IL-1β) production. Our results show that estrogen enhanced NLRP3 inflammasome activation in NESCs, resulting in increased IL-1β production. Progesterone decreased NLRP3 inflammasome activity with an increase in autophagy induction in estrogen-treated NESCs. Inhibition of NLRP3 inflammasome activity by progesterone was blocked by autophagy inhibition. However, progesterone failed to change NLRP3 inflammasome activity and autophagy induction in estrogen-treated ECSCs. In contrast, dienogest, a specific progesterone receptor agonist, reduced NLRP3 inflammasome-mediated IL-1β production through autophagy induction in ECSCs. Furthermore, autophagy induction was decreased and NLRP3 inflammasome activity was increased in endometriotic tissues, which was reversed by preoperative administration of dienogest. In conclusion, our results suggest that progesterone inhibits NLRP3 inflammasome activation through autophagy in endometrial stromal cells. However, this inhibitory effect is attenuated in endometriotic stromal cells due to an aberrant autophagic response to progesterone, which could lead to an altered inflammatory response in endometriosis.

Hsa-miR-199a-3p Inhibits Motility, Invasiveness, and Contractility of Ovarian Endometriotic Stromal Cells.

It is suggested that aberrantly expressed microRNAs are involved in the pathogenesis of endometriosis. Our previous study demonstrated that expression of the microRNA hsa-miR-199a-3p is attenuated in human endometriotic cyst stromal cells (ECSCs). The current study aimed to define the roles of hsa-miR-199a-3p in the development of endometriosis. ECSCs and normal endometrial stromal cells (NESCs) were isolated from ovarian endometrioma and normal endometrial tissues, respectively. We evaluated the effect of transfected hsa-miR-199a-3p on the migration, invasion, and contractility of ECSCs using Transwell migration assays, in vitro wound healing assays, Transwell invasion assays, and collagen gel contraction assays. We also examined the downstream target of hsa-miR-199a-3p with an online public database search and luciferase reporter assay. Expression of hsa-miR-199a-3p in ECSCs was significantly lower than that in NESCs, whereas the expression of p21-activated kinase 4 (PAK4) mRNA was significantly higher. Transfection of hsa-miR-199a-3p inhibited the migration, invasion, and contractility of ECSCs via inhibition of PAK4 mRNA expression. PAK4 was confirmed to be the direct target of hsa-miR-199a-3p. Transfection of PAK4 small interfering RNA and the PAK4 inhibitor PF-3758309 also inhibited ECSC migration, invasion, and contractility. These findings suggest that hsa-miR-199a-3p may act as a tumor suppressor in endometriosis development. Attenuation of hsa-miR-199a-3p expression was favorable for ECSCs to acquire the highly invasive, motile, and contractile characteristics of endometriotic cells and is involved in the development of endometriosis. Accordingly, PAK4 inhibitors may be promising for the treatment of endometriosis.

Nuclear factor-kappa B signaling in endometriotic stromal cells is not inhibited by progesterone owing to an aberrant endoplasmic reticulum stress response: a possible role for an altered inflammatory process in endometriosis.

Endoplasmic reticulum (ER) stress serves as a key modulator of the inflammatory response by controlling nuclear factor-kappaB (NF-κB) signaling. Previous studies from our laboratory have reported an abnormal induction of ER stress linked to progesterone resistance in human endometriotic cells. Therefore, an aberrant ER stress response to progesterone might contribute to the altered inflammatory response observed in endometriotic tissues. To evaluate this hypothesis, we investigated whether ER stress is involved in regulation of NF-κB in endometrial stromal cells and whether induction of aberrant ER stress in endometriotic stromal cells affects pro-inflammatory cytokine production. We found that tunicamycin-induced ER stress inhibited NF-κB activation and pro-inflammatory cytokine (IL-6 and COX2) production in TNF-α- or IL-1β-treated normal endometrial stromal cells (NECSs). Tunicamycin increased the expression of A20 and C/EBPβ, which are negative regulators of NF-κB, and this increase inhibited NF-κB activity in NESCs incubated with TNF-α or IL-1β. Similarly, progesterone increased A20 and C/EBPβ expression through upregulation of ER stress in NESCs, resulting in inhibition of NF-κB activity and IL-6 and COX2 production. However, progesterone had no significant effects on induction of ER stress, A20 or C/EBPβ expression, NF-κB activity or IL-6 or COX2 production in ovarian endometriotic cyst stromal cells (ECSCs). In contrast, upregulation of ER stress by tunicamycin significantly reduced IL-6 and COX2 production by inhibiting NF-κB activity in ECSCs. In conclusion, our results suggest that NF-κB activity in endometriotic stromal cells was not inhibited because of an aberrant ER stress response to progesterone, resulting in an increase in pro-inflammatory cytokine production.

Construction of a MicroRNA-mRNA Network Underlying Decidualized Endometriotic Cyst Stromal Cells Using Bioinformatics Analysis.

Background Decidualization of ectopic endometrium often leads to the extensive proliferation of local tissue and is easily misdiagnosed as malignant tumors. The study is aimed at constructing a microRNA- (miRNA-) mRNA network underlying decidualized endometriotic cyst stromal cells (ECSCs). Methods All data were collected from the Gene Expression Omnibus (GEO) database. Firstly, the differentially expressed genes (DEGs, adj. P‐Val < 0.05, | log FC | ≥1) and miRNAs (DEMs, P‐Val < 0.05, ∣log FC | ≥1) were analyzed by the limma package. Secondly, we predicted the target genes (TGs) of these DEMs through the TargetScan, miRDB, and miRTarBase databases. The overlapping genes between DEGs and TGs were screened out. Thirdly, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) enrichment analyses of the overlapping genes were performed for integrated discovery, visualization, and annotation. Then, the protein-protein interaction (PPI) network of the overlapping genes was conducted by the STRING database. Finally, we combined the PPI network and the miRNA-mRNA pairs to build a miRNA-mRNA network. Results There are 29 DEMs and 523 DEGs. Fourteen overlapping genes were screened out, and these genes were significantly enriched in metabolism and immunity. What is more, a miRNA-mRNA network, including 14 mRNAs and 9 miRNAs, was successfully constructed. Conclusions Taken together, the miRNA-mRNA regulatory networks described in this study may provide new insights in the decidualization of ECSCs, suggesting further investigations in novel pathogenic mechanisms.

Hsa-miR-100-5p, an overexpressed miRNA in human ovarian endometriotic stromal cells, promotes invasion through attenuation of SMARCD1 expression

BackgroundA number of microRNAs are aberrantly expressed in endometriosis and are involved in its pathogenesis. Our previous study demonstrated that has-miR-100-5p expression is enhanced in human endometriotic cyst stromal cells (ECSCs). The present study aimed to elucidate the roles of has-miR-100-5p in the pathogenesis of endometriosis.MethodsNormal endometrial stromal cells (NESCs) were isolated from normal eutopic endometrium without endometriosis. Using hsa-miR-100-5p-transfected NESCs, we evaluated the effect of hsa-miR-100-5p on the invasiveness of these cells by Transwell invasion assay and in-vitro wound repair assay. We also investigated the downstream signal pathways of hsa-miR-100-5p by microarray analysis and Ingenuity pathways analysis.Resultshsa-miR-100-5p transfection enhanced the invasion and motility of NESCs. After hsa-miR-100-5p transfection, mRNA expression of SWItch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1 (SMARCD1) was significantly attenuated. Whereas, the expression of matrix metallopeptidase 1 (MMP1) mRNA and active MMP1 protein levels was upregulated.ConclusionWe found that SMARCD1/MMP-1 is a downstream pathway of hsa-miR-100-5p. hsa-miR-100-5p transfection enhanced the motility of NESCs by inhibiting SMARCD1 expression and MMP1 activation. These findings suggest that enhanced hsa-miR-100-5p expression in endometriosis is involved in promoting the acquisition of endometriosis-specific characteristics during endometriosis development. Our present findings on the roles of hsa-miR-100-5p may thus contribute to understand the epigenetic mechanisms involved in the pathogenesis of endometriosis.

Chemokine expression profiles of ovarian endometriotic stromal cells in three-dimensional culture

Endometriosis is a chronic inflammatory disease which is associated with aberrant chemokine expression. We have established a three-dimensional (3D) floating collagen gel culture of human endometriotic cyst stromal cells (ECSCs) as an in vitro model of early-stage fibrosis formation in endometriosis. We evaluated the gene expression profiles of 3D-cultured ECSCs using a gene expression microarray. We identified and confirmed with reverse transcription-polymerase chain reaction that mRNA levels of CXCL1, CXCL2, CXCL3, CXCL8, and CCL20 in 3D-cultured ECSCs were significantly higher than in 2D-cultured ECSCs. The protein levels of CXCL1, CXCL2, CXCL8, and CCL20 in the supernatant of 3D-cultured ECSCs were significantly higher than in 2D-cultured ECSCs. It has been suggested that the 3D-culture model of ECSCs is more suitable for in vitro endometriosis research than 2D-culture. This microarray data provides a new platform to identify the candidate genes involved in the pathogenesis of endometriosis which could be masked in conventional 2D-culture.

Extracellular vesicle-mediated transfer of the lncRNA-TC0101441 promotes endometriosis migration/invasion

Extracellular vesicular long noncoding RNAs (lncRNAs) to influence recipient cells is emerging as a novel mechanism for disease progression. TC0101441 is a newly identified metastasis-related lncRNA involved in cancer. Since endometriosis exhibits prometastasis behavior similar to those observed in cancer, we aimed to investigate whether TC0101441 is involved in endometriosis and, if so, whether extracellular vesicular TC0101441 contributes to the migration/invasion of endometriotic cyst stromal cells (ECSCs). Clinically, we found that TC0101441 was highly expressed in ectopic endometria than in the eutopic and normal endometria. Serum extracellular vesicular TC0101441 levels were substantially increased in patients at stage III/IV endometriosis in comparison with stage I/II endometriosis and controls. In vitro, using TC0101441-high-expression ECSCs (ECSCs-H) as extracellular vesicles (EVs)-generating cells and TC0101441-low-expression ECSCs (ECSCs-L) as recipient cells, we observed that the PKH67-labeled ECSCs-H-derived EVs were effectively internalized by ECSCs-L. ECSCs-H-derived EVs shuttling TC0101441 were transferred to ECSCs-L, modulating their migratory/invasive abilities partially by regulating certain metastasis-related proteins, which eventually facilitated endometriosis migration/invasion. This study elucidates a potential crosstalk between ECSCs via EVs in endometriotic milieus, suggests a novel mechanism for endometriosis migration/invasion from the perspective of the “extracellular vesicular transfer of lncRNAs” and highlights the potential of circulating extracellular vesicular TC0101441 as a biomarker for endometriosis.

Dienogest regulates apoptosis, proliferation, and invasiveness of endometriotic cyst stromal cells via endoplasmic reticulum stress induction.

Dienogest, a specific progesterone receptor agonist, is used in the treatment of endometriosis. However, it is still unclear as to the mechanisms of therapeutic effects on endometriosis. Our recent study showed that endometriosis may be the result of aberrant endoplasmic reticulum (ER) stress induction due to progesterone resistance. This finding suggests that the regulation of ER stress induction may play a key role in treatment of endometriosis. Therefore, the anti-endometriotic effects of dienogest may be mediated by regulation of ER stress. To test this hypothesis, we elucidate whether dienogest affects endometriotic stromal cell apoptosis, proliferation and invasiveness by modulating ER stress-induced CCAAT/enhancer-binding protein homologous protein (CHOP) expression. Specifically, PRKR-like ER kinase (PERK)/eukaryotic initiation factor 2α (eIF2α)/activating transcription factor 4 (ATF4), inositol-requiring kinase 1 (IRE1)/TNF receptor-associated factor 2 (TRAF2)/apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) signaling, and downstream CHOP were evaluated to determine the involved ER stress-mediated regulation mechanism of CHOP expression. Our results show that progesterone treatment did not have any significant effects on ER stress, apoptosis, proliferation, and invasion in estrogen-treated endometriotic cyst stromal cells (ECSCs). However, dienogest treatment upregulated the induction of ER stress. It also led to increased apoptosis, and decreased proliferation and invasiveness. These dienogest-induced changes in apoptosis, proliferation and invasiveness were reversed by the ER stress inhibitor salubrinal. Furthermore, dienogest-induced ER stress increased CHOP expression through activation of both PERK/elf2α/ATF4 and IRE1/TRAF2/ASK1/JNK signaling. This upregulation was blocked by transfection with PERK and IRE1 siRNA, which decreased apoptosis and increased the proliferation and invasiveness of dienogest-treated ECSCs. Taken together, our findings indicate that dienogest enhances ER stress induction in endometriotic stromal cells, which affects apoptosis, proliferation and invasiveness via CHOP upregulation.

The Exosomal Long Noncoding RNA aHIF is Upregulated in Serum From Patients With Endometriosis and Promotes Angiogenesis in Endometriosis.

The transfer of long noncoding RNAs (lncRNAs) via exosomes to modulate recipient cells represents an important mechanism for disease progression. Antisense hypoxia-inducible factor (aHIF) is a well-known angiogenesis-related lncRNA. Here, we aimed to investigate the clinical implications of aHIF and exosomal aHIF in endometriosis and the involvement of exosome-shuttled aHIF in endometriosis angiogenesis. The distribution and expression of aHIF in ectopic, eutopic, and normal endometria was evaluated. Serum exosomal aHIF levels in patients with endometriosis were tested. The correlation between serum exosomal aHIF and aHIF expression in ectopic endometria was analyzed. Endometriotic cyst stromal cells (ECSCs)-derived exosomes were characterized. The internalization of exosomes by human umbilical vein endothelial cells (HUVECs) was observed. A series of in vitro assays were conducted to investigate the roles and mechanisms of exosomal aHIF in endometriosis angiogenesis. Clinically, aHIF was highly expressed in ectopic endometria and serum exosomes in patients with endometriosis. Serum exosomal aHIF was significantly correlated to aHIF expression in matched ectopic endometria. In vitro, PKH67-labeled exosomes derived from aHIF high expression ECSCs were effectively internalized by recipient HUVECs. Notably, exosome-shuttled aHIF was transferred from ECSCs to HUVECs, which in turn elicited proangiogenic behavior in HUVECs by activating vascular endothelial growth factor (VEGF)-A, VEGF-D, and basic fibroblast growth factor, thereby facilitating endometriosis angiogenesis. Our study illustrates a potential cell-cell communication between ECSCs and HUVECs in an ectopic environment, provides a novel mechanistic model explaining how ECSCs induce angiogenesis from the perspective of the "exosomal transfer of aHIF," and highlights the clinical value of circulating exosomal aHIF in endometriosis.

\u03b2-catenin signaling inhibitors ICG-001 and C-82 improve fibrosis in preclinical models of endometriosis

Endometriosis exhibits unique characteristics, such as fibrosis, resistance to apoptosis, and promotion of cell proliferation; however, its pathophysiology is not fully understood. Recurrence rates after treatment are high, and the progression risk continues until menopause; hence, more effective therapy for endometriosis is needed. CREB-binding protein (CBP)/β-catenin signaling inhibitors have demonstrated antifibrogenetic effects in liver, lung, and skin diseases. The present study evaluated the effects of two CBP/β-catenin signaling inhibitors, ICG-001 and C-82, on the progression of endometriosis using endometriotic cyst stromal cells from the ovary and normal endometrial stromal cells from the uterus. ICG-001 was also evaluated in a mouse model. ICG-001 and C-82 inhibited cell proliferation, fibrogenesis, and cell migration, and promoted apoptosis in vitro. ICG-001 inhibited the growth of endometriotic lesions in the mouse model. CBP/β-catenin signaling plays an important role in the pathophysiology of endometriosis. Inhibiting the CBP/β-catenin signal can be a therapeutic target for endometriosis.

Knockdown of vascular cell adhesion molecule 1 impedes transforming growth factor beta 1-mediated proliferation, migration, and invasion of endometriotic cyst stromal cells

PurposeEndometriosis is one of the most common, difficult, and complicated gynecological disorders. Vascular cell adhesion molecule 1 (VCAM-1) has been reported to be aberrantly expressed in patients with endometriosis. However, the exact role and mechanism of VCAM-1 in endometriosis remains unclear.MethodsThe expression of transforming growth factor beta 1 (TGF-β1) and VCAM-1 was determined by quantitative real-time polymerase chain reaction and western blotting. Human endometriotic cells were cultured and their responsiveness to TGF-β1 was evaluated by Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, and transwell migration and invasion assays.ResultsThe levels of TGF-β1 and VCAM-1 mRNA were upregulated in the endometriotic tissues. Knockdown of TGF-β1 in endometriotic cyst stromal cells caused a marked inhibition of cell proliferation, migration, and invasion. Treatment of endometriotic cyst stromal cells with TGF-β1 resulted in an obvious promotion of cell proliferation, migration, and invasion, and strikingly increased the protein expression of VCAM-1. Silencing of Smad3 abated TGF-β1-stimulated VCAM-1 expression. Furthermore, the promoting effects of TGF-β1 on the proliferation, migration, and invasion of endometriotic cyst stromal cells were blocked by silencing of VCAM-1.ConclusionKnockdown of VCAM-1 impedes TGF-β1-mediated proliferation, migration, and invasion of endometrial cells, thereby indicating that VCAM-1 may serve as a therapeutic target for endometriosis.

ATM expression is attenuated by promoter hypermethylation in human ovarian endometriotic stromal cells.

A number of genes involved in the pathogenesis of endometriosis are silenced by the hypermethylation of their promoter regions. We assessed the effect and mechanism of the DNA demethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) (10μM) on the cell cycle in human endometriotic cyst stromal cells (ECSCs) and normal endometrial stromal cells (NESCs) by flow cytometry. The DNA methylation status of G2/M checkpoint regulators were investigated by methylation-specific PCR. The expression of ataxia telangiectasia mutated (ATM) and the effect of 5-aza-dC on its expression were also evaluated by quantitative RT-PCR and western blotting analysis. 5-aza-dC treatment resulted in the cell cycle arrest of ECSCs at the G2/M phase. In contrast, 5-aza-dC did not affect the cell cycle of NESCs. The promoter region of the ATM gene was hypermethylated in ECSCs, but not in NESCs. ATM mRNA expression was attenuated in ECSCs compared to that in NESCs. Further, 5-aza-dC was found to restore ATM expression in ECSCs by its promoter demethylation. Our findings indicate that ATM promoter hypermethylation occurs in endometriosis, and that ATM silencing is involved in tumorigenesis during this disease; moreover, selective DNA demethylating agents and molecular target drugs against ATM silencing are promising for the treatment of endometriosis.

Involvement of endoplasmic reticulum stress in regulation of endometrial stromal cell invasiveness: possible role in pathogenesis of endometriosis.

Endoplasmic reticulum (ER) stress is known to reduce invasiveness in some cancer cells by inhibiting the AKT/mTOR pathway. A previous study from our laboratory suggested that ER stress is promoted by progesterone in human endometrial cells, which suggests that progesterone may inhibit endometrial cell invasiveness by up-regulating ER stress. Therefore, aberrant ER stress in response to progesterone may contribute to the altered invasiveness found in endometriotic tissues. To test this hypothesis, we elucidate whether ER stress is involved in regulation of human endometrial cell invasiveness through the AKT/mTOR pathway and if this involvement is associated with altered invasiveness in endometriotic cells. Specifically, we sought to determine the effects of ER stress on AKT/mTOR pathway by evaluating ER stress-mediated CHOP/TRIB3 signaling, a negative regulator of AKT. We found that ER stress marker GRP78 expression increased with CHOP and TRIB3 expression in normal endometrial stromal cells (NESCs) treated with tunicamycin, and this increase was accompanied by decreased AKT and mTOR activity and cellular invasiveness. Similarly, progesterone increased GRP78, CHOP and TRIB3 expression in NESCs. Subsequently, inhibition of AKT and mTOR activity decreased cellular invasiveness. This progesterone-induced decrease in cellular invasiveness was reversed by inhibition of ER stress. In contrast, progesterone did not change CHOP, TRIB3, AKT, mTOR or invasiveness in endometriotic cyst stromal cells. In contrast to normal endometrium, endometriotic tissues showed no changes in CHOP, TRIB3 and invasion-related proteins (MMP2 and MMP9) expression throughout the menstrual cycle. Taken together, our findings indicate that abnormal ER stress response to progesterone increased endometriotic stromal cell invasiveness via the AKT/mTOR pathway.

Chemokine expression of endometriotic cyst stromal cells in collagen gel three-dimensional culture

Chemokine expression of endometriotic cyst stromal cells in collagen gel three-dimensional culture

Arcyriaflavin a, a cyclin D1\u2013cyclin-dependent kinase4 inhibitor, induces apoptosis and inhibits proliferation of human endometriotic stromal cells: a potential therapeutic agent in endometriosis

BackgroundWe previously showed that microRNA-503 (miR-503) transfection into endometriotic cyst stromal cells (ECSCs) induced cell cycle arrest at the G0/G1 phase by suppressing cyclin D1. This finding prompted us to evaluate the potential therapeutic effects of cyclin D1 inhibitors in endometriotic cells. This study aimed to determine whether arcyriaflavin A, a representative inhibitor of cyclin D1–cyclin-dependent kinase 4 (CDK4), is beneficial in the treatment of endometriosis.MethodsECSCs were isolated from the ovarian endometriotic tissues of 32 women. The effects of arcyriaflavin A on cell viability and proliferation, vascular endothelial growth factor A expression, apoptosis, and cell cycle progression were evaluated using a modified methylthiazoletetrazolium assay, enzyme-linked immunosorbent assay (ELISA), Caspase-Glo® 3/7 assay, and flow cytometry.ResultsArcyriaflavin A significantly inhibited cell viability, proliferation, and angiogenesis of ECSCs as assessed using the 5-bromo-2-deoxyuridine (BrdU) and methylthiazoletetrazolium bromide (MTT) assays, and vascular endothelial growth factor (VEGF) ELISA. Arcyriaflavin A induced apoptosis as shown in the Caspase-Glo® 3/7 assay and cell death detection ELISA whilethe cell cycle was arrested at the G0/G1 phase.ConclusionThe findings indicate that cyclin D1–CDK4 inhibitors may be promising candidates for the treatment of endometriosis. This is the first study to demonstrate the potential usefulness of arcyriaflavin A as a therapeutic agent for endometriosis. Further studies of the effects of cyclin D1–CDK4 inhibitors on endometriosis may provide useful information on pathogenesis and treatment.

Decidualization Differentially Regulates microRNA Expression in Eutopic and Ectopic Endometrial Stromal Cells.

Decidualization of the endometrium and endometriosis involves the morphological and biochemical reprogramming of the estrogen-primed proliferative stromal compartment under the continuing influence of progesterone. Here, we evaluated the involvement of microRNA in the decidualization processes of normal endometrial stromal cells (NESCs) and endometriotic cyst stromal cells (ECSCs). In vitro decidualization of NESCs and ECSCs was induced by long-term culture with a combination of 0.5 mmol/L of dibutyryl cyclic adenosine monophosphate and 100 nmol/L of dienogest. We investigated the effect of in vitro decidualization on the microRNA and messenger RNA (mRNA) expression profiles of the NESCs and ECSCs using global microarray techniques and an Ingenuity Pathways Analysis. Decidualization differentially enhanced the miR-30a-5p expression in the NESCs and the miR-210 expression in the ECSCs. The enhanced miR-30a-5p expression in the NESCs correlated with the increased mRNA expression of Krüppel-like factor 9 and period circadian clock 3 as well as the decreased mRNA expression of tolloid-like 1, tolloid-like 2, and paired-like homeodomain 1. The enhanced expression of miR-210 in the ECSCs correlated with the decreased mRNA expression of growth hormone receptor and thymidine kinase 1. Although there is no direct evidence, we speculate that the loss of miR-30a-5p-mediated mechanisms of decidualization and the acquisition of miR-210-mediated mechanisms of decidualization may be involved in the progesterone resistance in endometriosis. Further investigations are necessary to test this speculation.

Aberrant PTEN expression in response to progesterone reduces endometriotic stromal cell apoptosis

In some human cancer cells, PTEN (phosphatase and tensin homolog deleted on chromosome 10) is known to regulate autophagy induction positively through the inhibition of PI3K/AKT pathway, leading to the activation of mTOR, a major negative regulator of autophagy. Recent studies reported that PTEN expression is abnormally decreased in endometriotic lesions. In endometriosis, abnormal PTEN expression may contribute to the alteration of endometrial cell autophagy, which may affect apoptosis because endometrial cell autophagy is directly involved in the regulation of apoptosis. To test this hypothesis, we evaluated the involvement of PTEN in the regulation of autophagy induction in human normal endometrial stromal cells (NESCs). In addition, we sought to determine whether aberrant PTEN expression in endometriotic cyst stromal cells (ECSCs) is associated with autophagy dysregulation, and a subsequent decrease in apoptosis. Our results show that PTEN expression was enhanced by progesterone treatment in NESCs. Subsequently, autophagy and apoptosis induction increased through the inhibition of AKT and mTOR activity. This progesterone-induced increase in apoptosis was reversed by the inhibition of autophagy induction using either mifepristone (progesterone receptor modulator) or PTEN inhibitor. In contrast, progesterone had no significant effects on PTEN expression, AKT, mTOR activity, autophagy or apoptosis in ECSCs. Furthermore, in contrast to normal eutopic endometrium, endometriotic tissues have constant PTEN expression, autophagy and apoptosis throughout the menstrual cycle. In conclusion, our results suggest abnormal PTEN expression in response to progesterone was observed in ECSCs, which led to the dysregulation of autophagy induction via AKT/mTOR signalling and a subsequent decrease in apoptosis.

MiR-503, a microRNA epigenetically repressed in endometriosis, induces apoptosis and cell-cycle arrest and inhibits cell proliferation, angiogenesis, and contractility of human ovarian endometriotic stromal cells.

Is the micro-RNA (miRNA) miR-503, downregulated in endometriotic cyst stromal cells (ECSCs) and does this affect the cell cycle, cell proliferation, angiogenesis and contractility of these cells? SUMMARY ANSWER: miR-503 expression is downregulated in ECSCs by DNA hypermethylation and this contributes to their proliferation, resistance to apoptosis, extracellular matrix (ECM) contractility and angiogenesis through effects on cyclin D1, B-cell lymphoma/leukemia (Bcl)-2, Ras homology A and vascular endothelial growth factor A (VEGF-A). A variety of miRNAs are demonstrated to involve in the pathogenesis of endometriosis. miR-503 is a miRNA with tumor-suppressor functions, whose expression is suppressed in ECSCs. We isolated ECSCs and normal endometrial stromal cells (NESCs) from ovarian endometriotic tissues (n=32) and eutopic endometrial tissues without endometriosis (n=8), respectively. We investigated the functions of miR-503 by using miR-503-transfected ECSCs and the DNA methylation status of miR-503 gene in ECSCs and NESCs by combined bisulfite restriction analysis. In ECSCs, miR-503 is downregulated by the DNA hypermethylation of its gene. The transfection of miR-503 into ECSCs resulted in the inhibition of cell proliferation and induction of cell-cycle arrest at G0/G1 phase through the suppression of cyclin D1, the induction of apoptosis through Bcl-2 suppression, the inhibition of VEGF-A production and the attenuation of ECM contractility via the suppression of Rho/Rho-associated coiled-coil-forming protein kinase-pathways. NA. The present experiments were carried out only with the stromal component of endometriosis and eutopic endometrium. The experiments with the eutopic endometrial stromal cells from women with endometriosis are not performed. Our findings indicate that epigenetically repressed miR-503 in ECSCs is involved in the acquisition of endometriosis-specific cellular functions. This work was supported in part by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (no. 13237327 to K.N., no. 26861335 to K.K. and no. 23592407 to H.N.) and the Kanzawa Medical Research Foundation (to K.K.). There are no conflicts of interest to declare.