Eutopic and ectopic stromal cells from patients with endometriosis exhibit differential invasive, adhesive, and proliferative behavior

Vitamin D and reproductive disorders: a comprehensive review with a focus on endometriosis

Vitamin D is a fat-soluble steroid hormone that was initially known only for regulating calcium and phosphorus levels and maintaining bone health. However, it was later discovered that many organs express vitamin D metabolizing enzymes and have a ligand for vitamin D, which regulates the expression of an extensive assortment of genes. As a result, vitamin D is indispensable for the proper function of organs, and its deficiency is believed to be a critical factor in symptoms and disorders such as cardiovascular diseases, autoimmune diseases, and cancers. The significance of vitamin D in reproductive tissues was recognized later, and studies have revealed its crucial role in male and female fertility, as well as proper reproductive function during pregnancy. Vitamin D deficiency has been identified as a risk factor for infertility, gonadal cancers, pregnancy complications, polycystic ovary syndrome, and endometriosis. However, data investigating the association between vitamin D levels and reproductive disorders, including endometriosis, have encountered inconsistencies. Therefore, the present study aims to review existing research on the effect of vitamin D on proper reproductive function, and the role of deficiency in reproductive diseases and specifically focuses on endometriosis.

Horizons in Endometriosis: Proceedings of the Montreux Reproductive Summit, 14-15 July 2023

Endometriosis is a complex and chronic gynaecological disorder that affects millions of women worldwide, leading to significant morbidity and impacting reproductive health. This condition affects up to 10% of women of reproductive age and is characterised by the presence of endometrial-like tissue outside the uterus, potentially leading to symptoms such as chronic pelvic pain, dysmenorrhoea, dyspareunia, and infertility. The Montreux summit brought a number of experts in this field together to provide a platform for discussion and exchange of ideas. These proceedings summarise the six main topics that were discussed at this summit to shed light on future directions of endometriosis classification, diagnosis, and therapeutical management. The first question addressed the possibility of preventing endometriosis in the future by identifying risk factors, genetic predispositions, and further understanding of the pathophysiology of the condition to develop targeted interventions. The clinical presentation of endometriosis is varied, and the correlation between symptoms severity and disease extent is unclear. While there is currently no universally accepted optimal classification system for endometriosis, several attempts striving towards its optimisation - each with its own advantages and limitations - were discussed. The ideal classification should be able to reconcile disease status based on the various diagnostic tools, and prognosis to guide proper patient tailored management. Regarding diagnosis, we focused on future tools and critically discussed emerging approaches aimed at reducing diagnostic delay. Preserving fertility in endometriosis patients was another debatable aspect of management that was reviewed. Moreover, besides current treatment modalities, potential novel medical therapies that can target underlying mechanisms, provide effective symptom relief, and minimise side effects in endometriotic patients were considered, including hormonal therapies, immunomodulation, and regenerative medicine. Finally, the question of hormonal substitution therapy after radical treatment for endometriosis was debated, weighing the benefits of hormone replacement.

Regulated Cell Death in Endometriosis

Regulated cell death (RCD) represents a distinct mode of cell demise, differing from accidental cell death (ACD), characterized by specific signaling cascades orchestrated by diverse biomolecules. The regular process of cell death plays a crucial role in upholding internal homeostasis, acting as a safeguard against biological or chemical damage. Nonetheless, specific programmed cell deaths have the potential to activate an immune-inflammatory response, potentially contributing to diseases by enlisting immune cells and releasing pro-inflammatory factors. Endometriosis, a prevalent gynecological ailment, remains incompletely understood despite substantial progress in unraveling associated signaling pathways. Its complexity is intricately tied to the dysregulation of inflammatory immune responses, with various RCD processes such as apoptosis, autophagic cell death, pyroptosis, and ferroptosis implicated in its development. Notably, limited research explores the association between endometriosis and specific RCD pathways like pyroptosis and cuproptosis. The exploration of regulated cell death in the context of endometriosis holds tremendous potential for further advancements. This article thoroughly reviews the molecular mechanisms governed by regulated cell death and their implications for endometriosis. A comprehensive understanding of the regulated cell death mechanism in endometriosis has the potential to catalyze the development of promising therapeutic strategies and chart the course for future research directions in the field.

MLLT11 Regulates Endometrial Stroma Cell Adhesion, Proliferation and Survival in Ectopic Lesions of Women with Advanced Endometriosis

MLLT11 is a gene implicated in cell differentiation and the development and progression of human cancers, but whose role in the pathogenesis of endometriosis is still unknown. Using quantitative RT-PCR and immunohistochemistry, we analyzed 37 women with and 33 women without endometriosis for differences in MLLT11 expression. We found that MLLT11 is reduced in the ectopic stroma cells of women with advanced stage endometriosis compared to women without endometriosis. MLLT11 knockdown in control stroma cells resulted in the downregulation of their proliferation accompanied by G1 cell arrest and an increase in the expression of p21 and p27. Furthermore, the knockdown of MLLT11 was associated with increased apoptosis resistance to camptothecin associated with changes in BCL2/BAX signaling. Finally, MLLT11 siRNA knockdown in the control primary stroma cells led to an increase in cell adhesion associated with the transcriptional activation of ACTA2 and TGFB2. We found that the cellular phenotype of MLLT11 knockdown cells resembled the phenotype of the primary endometriosis stroma cells of the lesion, where the levels of MLLT11 are significantly reduced compared to the eutopic stroma cells of women without the disease. Overall, our results indicate that MLLT11 may be a new clinically relevant player in the pathogenesis of endometriosis.

Establishment of a novel glycolysis-immune-related diagnosis gene signature for endometriosis by machine learning

PURPOSE

The objective of this study was to investigate the key glycolysis-related genes linked to immune cell infiltration in endometriosis and to develop a new endometriosis (EMS) predictive model.

METHODS

A training set and a test set were created from the Gene Expression Omnibus (GEO) public database. We identified five glycolysis-related genes using least absolute shrinkage and selection operator (LASSO) regression and the random forest method. Then, we developed and tested a prediction model for EMS diagnosis. The CIBERSORT method was used to compare the infiltration of 22 different immune cells. We examined the relationship between key glycolysis-related genes and immune factors in the eutopic endometrium of women with endometriosis. In addition, Gene Ontology (GO)-based semantic similarity and logistic regression model analyses were used to investigate core genes. Reverse real-time quantitative PCR (RT-qPCR) of 5 target genes was analysed.

RESULTS

The five glycolysis-related hub genes (CHPF, CITED2, GPC3, PDK3, ADH6) were used to establish a predictive model for EMS. In the training and test sets, the area under the curve (AUC) of the receiver operating characteristic curve (ROC) prediction model was 0.777, 0.824, and 0.774. Additionally, there was a remarkable difference in the immune environment between the EMS and control groups. Eventually, the five target genes were verified by RT-qPCR.

CONCLUSION

The glycolysis-immune-based predictive model was established to forecast EMS patients' diagnosis, and a detailed comprehension of the interactions between endometriosis, glycolysis, and the immune system may be vital for the recognition of potential novel therapeutic approaches and targets for EMS patients.

Evaluation of expression of biomarkers of PLAGL1 (ZAC1), microRNA, and their non-coding RNAs in patients with endometriosis

Since the PLAGL1 (ZAC1) gene is expressed in the human endometrium. It may be involved in the etiology of endometrial disorders by its abnormal regulation and expression. This study aimed to investigate the Zac1 gene and related microRNA and LncRNA and its alterations in patients with endometriosis. Blood plasma, ectopic (EC) and eutopic (EU) endometrial samples were gathered from 30 patients with endometriosis and 30 healthy fertile women, and the Q-PCR technique was used to determine the expression level of Zac1 mRNA and microRNAs (miR-1271-5p, hsa-miR-490-3pin) and LncRNAs (TONSL-AS1 TONSL, KCNQ1OT1 KCNQ1). According to the results, the Zac1 gene and KCNQ1OT1 KCNQ1, TONSL-AS1 TONSL LncRNA expression were significantly decreased in the endometriosis group versus the control group (P < 0.05). MiR-1271-5p and hsa-miR-490-3pin microRNA expression were significantly raised in the endometriosis group as opposed to the control group (P < 0.05). In summary, this research for the first time revealed that identifying Zac1 expression provides us with new indicators for evaluating endometriosis.

Low-Nutrient Environment-Induced Changes in Inflammation, Cell Proliferation, and PGC-1α Expression in Stromal Cells with Ovarian Endometriosis

Although nutrient status plays an important role in cell metabolism, its significance in endometriosis is obscure. Herein, we investigated the effects of a low-nutrient microenvironment on endometriosis. Stromal cells (SCs) from ovarian endometrioma (OESCs) or normal endometrium without endometriosis (NESCs) were isolated and cultured. A low-nutrient microenvironment was replicated by replacing the culture medium with Hank's balanced salt solution. OESC and NESC proliferation under the low-nutrient condition was measured. The expression of exacerbating factors in endometriosis under the low-nutrient condition was examined at the mRNA and protein levels. OESCs showed higher proliferation than NESCs under the low-nutrient condition. In OESCs, the low-nutrient condition upregulated the mRNA expression of vascular endothelial growth factor (VEGF), interleukin-6 and -8, aromatase, Bcl-2, and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) and downregulated that of BAX and induced transcription of PI.3, PII, and exon II. Western blotting revealed elevated VEGF and PGC-1α expression under the low-nutrient condition in OESCs. These changes coincided with the elevated expression of PGC-1α, which was reduced at the mRNA level upon nutrient status rescue. Endometriosis is exacerbated by altered angiogenesis, inflammation, anti-apoptosis, and local estrogen production while trying to survive under a low-nutrient microenvironment; it may be attributed to PGC-1α-mediated metabolic mechanisms.

Total Flavonoids of Polygala fallax Hemsl Induce Apoptosis of Human Ectopic Endometrial Stromal Cells through PI3K/AKT/Bcl-2 Signaling Pathway

OBJECTIVE

The objective of this study was to explore the inhibitory effect of total flavonoids of Polygala fallax Hemsl (PFHF) on human ectopic endometrial stromal cells (HEcESCs) and its mechanism.

DESIGN

The apoptosis, cell cycle, migration, and invasion ability of HEcESCs (Fresh human ovarian endometriosis tissue was used for primary culture) after PFHF treatment were detected, and the mechanism of action was explored.

MATERIALS

The Polygala fallax Hemsl (PFH), RPMI 1640 culture medium, Dulbecco's modified Eagle's medium (DMEM)/F-12, fetal bovine serum, penicillin/streptomycin, cell counting kit-8 (CCK-8) kit, trypsin, phenylmethylsulfonyl fluoride, radioimmunoprecipitation assay tissue/cell lysate, bicinchoninic acid protein concentration detection kits, protein loading buffer, the apoptosis and cell cycle extraction kits, the matrix glue, TRIzol Universal Reagent, the reverse transcription kit, AB HS Green qPCR Mix, the ECL chromogenic solution, enzyme labeling instrument, flow cytometry, automatic real-time fluorescence quantitative PCR instrument, Goat anti-rabbit, rabbit anti-β-actin, vimentin, phosphatidylinositol 3 kinase (PI3K), protein kinase B (AKT), B-cell lymphoma-2 (Bcl-2), Bcl-extra long (Bcl-xl), Bcl-2 associated death promoter (Bad) antibody, Alexa Fluor 594-labeled secondary antibody, the inverted microscope, the constant temperature carbon dioxide cell incubator.

SETTING

Five parts included introduction, materials and methods, results, discussion, and conclusion.

METHODS

The potential targets and pathways of PFHF in the treatment of endometriosis were predicted by network pharmacology. The effect of PFHF on the proliferation, apoptosis and cell cycle, migration, and invasion of HEcESCs was detected by CCK-8 method, flow cytometry, and Transwell chamber experiment. Label-free quantitative proteomics based on mass spectrometry was used to analyze the protein mass spectrum of differential expression of HEcESCs before and after PFHF, and the biological information was analyzed. The effects of PFHF on the mRNA and protein expression of pathway-related genes predicted in HEcESCs were detected by reverse transcription-quantitative polymerase chain reaction and Western blotting.

RESULTS

The network pharmacology predicts that PFHF treats endometriosis through PI3K/AKT signaling pathway. Compared with control group (DMEM/F-12 medium alone), the high dose PFHF can significantly reduce the viability, migration, and invasion of HEcESCs, increase the apoptosis rate of HEcESCs, and make the HEcESCs accumulated in G0/G1 phase in a time- and dose-dependent manner (p < 0.05). The analysis of label-free quantitative proteomics indicated that PFHF flavonoids may induce apoptosis of EESCs through PI3K/AKT signaling pathway. The results of RT-qPCR and Western blotting showed that the expressions of PI3K, AKT, Bcl-2, and Bcl-xl were significantly downregulated, while the bad expression was upregulated in HEcESCs treated with PFHF (p < 0.05).

LIMITATIONS

This research investigated the effects of PFHF on the stromal endometriotic cells only. So it is unknown how PFHF can affect the entire endometriotic lesion. And the research is carried out in vitro, which gives no impression about the bioavailability of the flavonoids.

CONCLUSION

PFHF reduces the expression of PI3K, AKT, Bcl-2, and Bcl-xl through the PI3K/AKT/Bcl-2 signaling pathway to inhibit HEcESCs proliferation, migration, and invasion and promote their apoptosis.

Effect of active vitamin D on proliferation, cell cycle and apoptosis in endometriotic stromal cells

RESEARCH QUESTION

What is the effect of vitamin D3 (1,25(OH)₂D₃) on proliferation, cell cycle and apoptosis of endometrial stromal cells (ESC) in endometriotic patients?

DESIGN

ESC isolated from 10 women with endometriosis and 10 healthy controls were treated with 1,25(OH)₂D₃. The proliferation of control endometrial stromal cells (CESC), eutopic endometrial stromal cells (EuESC) and ectopic endometrial stromal cells (EESC) was analysed 72 h after the treatment using methyl thiazolyl tetrazolium assay. Propidium iodide staining and flow cytometry were used to determine the cell cycle distribution in ESC. Annexin V/propidium iodide double staining was used to evaluate apoptosis in ESC.

RESULTS

In the presence of oestrogen, 1,25(OH)₂D₃ treatment inhibited the proliferation of ESC from all three origins (P = 0.009 for CESC, P = 0.005 for EuESC and P < 0.001 for EESC). The percentage of S phase cells in EESC was higher than in EuESC and CESC (P = 0.002 and P = 0.001, respectively). The percentage of S phase cells in EuESC was higher than in CESC (P = 0.005). The percentage of G1 phase cells in EESC was lower than that of EuESC and CESC (P = 0.003 and P = 0.002, respectively) and the percentage of G1 phase cells in EuESC was lower than that of CESC (P = 0.007). Moreover, 1,25(OH)₂D₃ inhibited cell cycle regardless of cell type (P = 0.002 in EESC, P = 0.001 in EuESC and P = 0.014 in CESC), but in the absence of oestrogen, inhibited cell cycle only in EuESC (P = 0.012).

CONCLUSIONS

Although 1,25(OH)₂D₃ increased apoptotic and necrotic cells and decreased live cells in the EuESC and EESC, it did not affect apoptosis in CESC and only increased necrotic cells. These findings indicate that 1,25(OH)₂D₃ potentially has a growth-inhibiting and pro-apoptotic effect on ESC from endometriotic patients.

Telocytes and endometriosis

Endometriosis involving the presence and growth of glands and stroma outside the uterine cavity is a common, inflammatory, benign gynecologic disease. Nevertheless, no single theory can exactly account for the pathogenesis of endometriosis. Telocytes, a kind of novel mesenchymal cells, have been suggested to be crucial in promoting angiogenesis and increasing the activity of endometrial interstitial cells and inflammatory cells. Given above roles, telocytes may be considered as the possible pathogenesis of endometriosis. We reviewed the current literature on telocytes. The following aspects were considered: (A) the telocytes' typical characteristics, function, and morphological changes in endometriosis; (B) the potential role of telocytes in endometriosis by impacting the inflammation, invasion, and angiogenesis; (C) telocytes as the potential treatment options for endometriosis.

Review of the Potential Therapeutic Effects and Molecular Mechanisms of Resveratrol on Endometriosis

Endometriosis is a hormone-dependent inflammatory disease characterized by the existence of endometrial tissues outside the uterine cavity. Pharmacotherapy and surgery are the current dominant management options for endometriosis. The greater incidence of recurrence and reoperation after surgical treatment as well as the adverse effects of medical approaches predispose patients to potential limitations for their long-term usage. Consequently, it is essential to explore novel supplementary and alternative drugs to ameliorate the therapeutic outcomes of endometriotic patients. Resveratrol is a phenolic compound that has attracted increasing interest from many researchers due to its pleiotropic biological activities. Here, we review the possible therapeutic efficacies and molecular mechanisms of resveratrol against endometriosis based on in vitro, animal, and clinical studies. The potential mechanisms of resveratrol include anti-proliferative, pro-apoptotic, anti-angiogenic, anti-oxidative stress, anti-invasive and anti-adhesive effects, thereby suggesting that resveratrol is a promising candidate for endometriosis. Because most studies have investigated the effectiveness of resveratrol on endometriosis via in vitro trials and/or experimental animal models, further high-quality clinical trials should be undertaken to comprehensively estimate the clinical application feasibility of resveratrol on endometriosis.

LncRNA HOTAIR regulates cell invasion and migration in endometriosis through miR-519b-3p/PRRG4 pathway

Endometriosis is a common benign disease in gynecology and has malignant biological behaviors, such as hyperplasia, invasion, metastasis, and recurrence. However, the pathogenesis of endometriosis remains unclear. The present study aimed to investigate whether LncRNA HOTAIR regulates cell invasion and migration in endometriosis by regulating the miR-519b-3p/PRRG4 pathway. The qRT-PCR results showed that the average relative expression of LncRNA HOTAIR was much higher in ectopic endometrial tissues than in eutopic endometrial tissues. Scratch and transwell assays showed that the cell migration and invasion ability of LncRNA HOTAIR overexpression group was significantly higher than those in the control group. Conversely, the LncRNA HOTAIR knockdown group showed the opposite results. Bioinformatics analysis suggested that the downstream target genes of LncRNA HOTAIR were miR-519b-3p and Prrg4. Knockdown of LncRNA HOTAIR can reduce the up-regulation of Prrg4 by miR-519b-3p and then inhibit the invasion and migration ability of endometrial stromal cells. In Conclusion, LncRNA HOTAIR can regulate the ability of invasion and migration of endometrial stromal cells, and its mechanism is proved by regulating the miR-519b-3p/PRRG4 pathway.

The Gut Microbiota: A Double Edge Sword in Endometriosis

Endometriosis that afflicts 1 in 10 women of reproductive age is characterized by growth of endometrial tissue in the extra-uterine sites and encompasses metabolic-, immunologic- and endocrine-disruption. Importantly, several comorbidities are associated with endometriosis, especially autoimmune disorders such as inflammatory bowel disease. Primarily thought of as a condition arising from retrograde menstruation, emerging evidence uncovered a functional link between the gut microbiota and endometriosis. Specifically, recent findings revealed altered gut microbiota profiles in endometriosis and in turn this altered microbiota appears to be causal in the disease progression, implying a bi-directional crosstalk. In this review, we discuss the complex etiology and pathogenesis of endometriosis emphasizing on this recently recognized role of gut microbiome. We review the gut microbiome structure and functions and its complex network of interactions with the host for maintenance of homeostasis that is crucial for disease prevention. We highlight the underlying mechanisms on how some bacteria promotes disease progression and others protects against endometriosis. Further, we highlight the areas that require future emphases in the gut microbiome-endometriosis nexus and the potential microbiome-based therapies for amelioration of endometriosis.

Therapeutic Strategies Focused on Cancer-Associated Hypercoagulation for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is associated with chemotherapy resistance and poor prognosis, especially in advanced cases. Although comprehensive genomic analyses have clarified the significance of genomic alterations such as ARID1A and PIK3CA mutations in OCCC, therapeutic strategies based on genomic alterations have not been confirmed. On the other hand, OCCC is clinically characterized by a high incidence of thromboembolism. Moreover, OCCC specifically shows high expression of tissue factor and interleukin-6, which play a critical role in cancer-associated hypercoagulation and may be induced by OCCC-specific genetic alterations or the endometriosis-related tumor microenvironment. In this review, we focused on the association between cancer-associated hypercoagulation and molecular biology in OCCC. Moreover, we reviewed the effectiveness of candidate drugs targeting hypercoagulation, such as tissue factor- or interleukin-6-targeting drugs, anti-inflammatory drugs, anti-hypoxia signaling drugs, anticoagulants, and combined immunotherapy with these drugs for OCCC. This review is expected to contribute to novel basic research and clinical trials for the prevention, early detection, and treatment of OCCC focused on hypercoagulation.

Controlling Semi-Invasive Activity of Human Endometrial Stromal Cells by Inhibiting NF-kB Signaling Pathway Using Aloe-emodin and Aspirin

Background:

Inflammation and its master regulator, Nuclear Factor-kB (NF-kB), have been implicated in the development of endometriosis. Inhibition of NF-kB pathway using small molecules ameliorated disease progression and reduced the lesion size; nevertheless, the underlying mechanism is not fully understood. Therefore, this study, is an attempt to assess whether inhibiting NF-kB signaling by aloe-emodin (AE) or aspirin (Asp), as anti-inflammatory compounds, can suppresses the invasive activity of human endometrial stromal cells at stage IV endometriosis.

Methods:

The eutopic and healthy endometrial biopsies from a total of 8 infertile women with confirmed endometriosis and 8 women without endometriosis were digested and the single cells were cultured. Gene and protein markers of proliferation, migration, adhesion, and invasion of eutopic endometrial stromal cells (EuESCs) with and without treatment with AE or Asp, as well as control endometrial stromal cells (CESCs) was analyzed using q-PCR and immunofluorescence staining, respectively. Comparison between groups was performed using one-way ANOVA and the Bonferroni post hoc and p≤0.5 was considered statistically significant.

Results:

There was an association between NF-kB overexpression and higher proliferation/adhesion capacity in EuESCs. EuESCs (at stage IV endometriosis) displayed no invasive and migratory behaviors. Pre-treatment of EuESCs with AE or Asp significantly attenuated NF-kB expression and reduced proliferative, adhesive, invasive, and migratory activity of endometrial cells (p≤0.5).

Conclusion:

Eutopic endometrial stromal cells seem to have a semi-invasive activity which is largely suppressed by AE or Asp. It can be suggested that both Asp and AE (as potent NF-kB inhibitors) can be used as a supplement in conventional endometriosis treatments.

Expression levels of MCP-1, HGF, and IGF-1 in endometriotic patients compared with non-endometriotic controls

BACKGROUND

To study the concentrations of monocyte chemoattractant protein-1 (MCP-1), hepatocyte growth factor (HGF), and insulin-like growth factor-1 (IGF-1) in peritoneal fluid (PF) and serum, and to evaluate their expressions by PF and peripheral blood mononuclear cells (PFMCs and PBMCs, respectively), and ectopic and eutopic endometrial stromal cells of patients with endometriosis (EESCs and EuESCs, respectively) compared with controls.

METHODS

The concentrations of mentioned cytokines in serum and PF, as well as their expression in PBMCs, PFMCs, EuESCs and EESCs from endometriosis patients and controls were assessed.

RESULTS

The levels of MCP-1, HGF, and IGF-1 in serum and PF in women with endometriosis were significantly higher than the controls (P < 0.05-P < 0.001). Gene expression of MCP-1 and IGF-1 in the PFMCs, PBMCs and EESCs also showed an increased level compared to controls (P < 0.05-P < 0.01). The protein expression of MCP-1 and IGF-1 by PFMCs was statistically higher in endometriotic women (P < 0.05 and P < 0.01, respectively). The gene and protein expression of HGF in PFMCs and its gene expression by EESCs were significantly higher in endometriotic women compared to controls (P < 0.05-P < 0.01).

CONCLUSIONS

The higher concentrations of mentioned cytokines in serum and PF and their higher expression by PFMCs and EESCs in endometriosis patients may contribute to the development of endometriosis.

Exosomes and their cargo are important regulators of cell function in endometriosis

Endometriosis is a chronic oestrogen-dependent gynaecological disorder characterized by non-menstrual pelvic pain, infertility and the extrauterine growth of endometrial-like glands and stroma. It has been noted that the eutopic endometrium of women with endometriosis is functionally distinct from that of women without endometriosis. Moreover, ectopic endometrial implants are functionally different from the eutopic endometrium of women with endometriosis. However, the mechanisms directing these differences are ill-defined. It is proposed here that small membrane-bound extracellular vesicles called exosomes are important vehicles in the protection and transport of signalling molecules central to the dysregulation of endometrial function in women with endometriosis. Therefore, a critical review of the literature linking exosomes and their cargo to the pathobiology of endometriosis was conducted. Circulating peritoneal fluid and endometrial cell exosomes contained long non-coding RNA, miRNA and proteins involved in histone modification, angiogenesis and immune modulation that differed significantly in women with endometriosis compared with controls. Moreover, experimental evidence supports a role for exosomes and their cargo in angiogenesis, neurogenesis, immune modulation and endometrial stromal cell invasion. It is therefore suggested that exosomes play an important role in the pathophysiology of endometriosis.

The effects of resveratrol on the expression of VEGF, TGF-β, and MMP-9 in endometrial stromal cells of women with endometriosis

Resveratrol is a phytochemical with anti-angiogenic, anti-inflammatory, and antioxidant properties. The present study has evaluated the effect of resveratrol on the expression of vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β) and matrix metalloproteinase-9 (MMP-9) as factors related to endometriosis progression. Thirteen eutopic (EuESCs) and 8 ectopic (EESCs) endometrial stromal cells from women with endometriosis and 11 control endometrial stromal cells (CESCs) were treated with resveratrol (100 µM) for 6, 24 and 48 h. The gene and protein expression levels of VEGF, TGF-β, and MMP-9 were measured using real-time PCR and ELISA methods, respectively. Results showed that the basal gene and protein expression of VEGF and MMP-9 were higher in EESCs compared to EuESCs and CESCs (P < 0.01 to  < 0.001 and P < 0.05 to  < 0.01 respectively). Also, resveratrol treatment decreased the gene and protein expression of VEGF and MMP-9 in EuESCs, EESCs and CESCs (P < 0.05 to  < 0.01 and P < 0.05 to  < 0.01 respectively) and gene and protein expression of TGF-β in EESCs and EuESCs (P < 0.05 to  < 0.01). The effect of resveratrol in reduction of VEGF gene expression was statistically more noticeable in EESCs compared to EuESCs and CESCs (P < 0.05). According to the findings, resveratrol may ameliorate endometriosis progression through reducing the expression of VEGF, TGF-β, and MMP-9 in endometrial stromal cells (ESCs).

Expression of Talin-1 in endometriosis and its possible role in pathogenesis

BACKGROUND

Endometriosis is a disease that involves active cell invasion and migration. Talin-1 can promote cell invasion, migration and adhension in various cancer cells, but its role in endometriosis has not been investigated. This study was to investigate the expression level of Talin-1 in endometriosis and the role of Talin-1 in the proliferation, adhesion, migration, and invasion of human endometrial stromal cells (ESCs).

METHODS

Ectopic and eutopic endometrial tissues were collected from women with endometriosis, and the control endometrial tissues were obtained from patients without endometriosis. The expression level of Talin-1 was detected in each sample using quantitative real-time polymerase chain reaction and immunohistochemistry. The expression of Talin-1 was inhibited using RNA interference in ESCs, and its proliferation, apoptosis, adhesion, migration, and invasion capacity were analyzed. Western blotting was performed to detect the expression of related molecules after the downregulation of Talin-1.

RESULTS

The results showed that the mRNA and protein expression of Talin-1 were significantly increased in the ectopic endometrium and eutopic endometrial tissues compared with the controls. The knockdown of Talin-1 did not affect the proliferation and apoptosis of ESCs. The results indicated that the downexpression of Talin-1 inhibited the adhesion, invasion, and migration of ESCs. In addition, the expressions of N-cadherin, MMP-2, and integrin β3 were significantly lower after the deregulation of Talin-1, whereas the levels of E-cadherin were significantly increased.

CONCLUSIONS

The expression of Talin-1 was increased in the ectopic and eutopic endometrial tissues compared with the control endometrium. The downregulation of Talin-1 inhibited the adhesion, invasion, and migration of ESCs.

SMURF1-mediated ubiquitylation of SHP-1 promotes cell proliferation and invasion of endometrial stromal cells in endometriosis

Background

Endometriosis is a widespread benign gynecological disorder. The signal transducer and activator of transcription 3 (STAT3) signaling pathway plays an important role in the pathogenesis of endometriosis through regulating proliferation and invasion of endometrial stromal cells. Furthermore, the protein tyrosine phosphatase (PTP), SH2 domain-containing phosphatase 1 (SHP-1), negatively regulates STAT3 activation. However, regulation of the SHP-1-STAT3 pathway in the pathogenesis of endometriosis remains unclear.

Methods

Cell proliferation and invasion were assessed by Cell Counting Kit-8 (CCK-8) assay and Transwell analysis, respectively, to investigate the role and regulation of the SHP-1-STAT3 pathway in the proliferation and invasion of endometrial stromal cells. Expression of Smad ubiquitin regulatory factor 1 (SMURF1), SHP-1, matrix metalloproteinase 2 (MMP2), MMP9, STAT3, and phospho-STAT3 (p-STAT3) level in patients with endometriosis were measured by Western blotting and/or immunohistochemical staining. The interaction between SMURF1 and SHP-1 was investigated by co-immunoprecipitation and ubiquitylation analysis.

Results

The present study demonstrated that downregulation of SHP-1 expression in patients with endometriosis was negatively correlated with SMURF1 expression. SMURF1, an E3 ubiquitin ligase, activated the STAT3 pathway via ubiquitylation and degradation of SHP-1. Furthermore, SMURF1 promoted cell proliferation and invasion of endometrial stromal cells by activating STAT3 signaling and expression of its downstream targets, MMP2 and MMP9, whereas SHP-1 demonstrated an inverse effect. Additionally, SHP-1 inhibited SMURF1-mediated cell invasion and proliferation of endometrial stromal cells.

Conclusions

Our findings indicate that SMURF1-mediated ubiquitylation of SHP-1 regulates endometrial stromal cell proliferation and invasion during endometriosis.

LINC01116 promotes proliferation and migration of endometrial stromal cells by targeting FOXP1 via sponging miR-9-5p in endometriosis

Endometriosis is a common multi-factorial gynaecological disease. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of endometriosis. In the present study, the expression profiles of lncRNAs in 6 pairs of endometriosis ectopic endometrium (ecEM) and eutopic endometrium (euEM) tissues were analysed by RNA sequencing. From the profiles, LINC01116 was found to be up-regulated in ecEM tissues compared to euEM tissues and was verified by quantitative real-time PCR (qRT-PCR). Then, functional experiments demonstrated that LINC01116 promoted the proliferation and migration of ectopic primary endometrial stromal cells (ESCs), while miR-9-5p exerted the opposite effects. Dual-luciferase reporter assays verified that LINC01116 directly sponged miR-9-5p and relieved the suppression of its target, Forkhead box protein P1 (FOXP1). Rescue experiments further demonstrated that LINC01116 could promote proliferation and migration of ESCs by targeting FOXP1 via sponging miR-9-5p. Overall, our study illuminates that LINC01116 promotes the progression of endometriosis through the miR-9-5p/FOXP1 axis. This finding provides a novel therapeutic target for patients with endometriosis.

Vitamin D deficiency as a risk factor for endometriosis in Iranian women

PURPOSE

Vitamin D (Vit D), as an immunomodulator, has been hypothesized to play a critical role in the pathogenesis of endometriosis. Thus, in this study, we evaluated whether there is an association between 25-hydroxyvitamin D [25(OH)D] and susceptibility to endometriosis in Iranian women.

METHODS

Women at reproductive age, including 56 healthy women and 54 patients with endometriosis, were enrolled in the study. Serum levels of 25(OH)D, calcium, parathyroid hormone (PTH), and peritoneal fluid (PF) levels of 25(OH)D were assessed.

RESULTS

The serum and PF levels of 25(OH)D in the patients with endometriosis were significantly lower than the control group (P = 0.001 and P = 0.03, respectively). Subjects with serum levels of 25(OH)D lower than 20 ng/mL had a 2.7 times higher risk of endometriosis than people with 25(OH)D serum levels higher than 20 ng/mL (non-deficient) (OR = 2.7, 95 % confidence interval: 1.24-5.80, P = 0.01). The serum levels of calcium and PTH were significantly lower and higher in patients with endometriosis compared with controls, respectively (P < 0.001, P = 0.02, respectively). Also, the serum levels of 25(OH)D were lower in stages I-II endometriosis than stage III-IV; however, no significant difference was observed.

CONCLUSION

Our findings showed that people with Vit D deficiency are at higher risk of endometriosis.

Resveratrol treatment reduces expression of MCP-1, IL-6, IL-8 and RANTES in endometriotic stromal cells

Endometriosis is an inflammatory disease affecting reproductive‐aged women. Immunologic disturbance, as well as inflammation, have crucial roles in the pathogenesis of endometriosis. In this study, we evaluated the effects of resveratrol treatment on expression of monocyte chemotactic protein‐1 (MCP‐1), interleukin‐6 (IL‐6), IL‐8, and regulated upon activation, normal T cell expressed and secreted (RANTES) in endometrial stromal cells from patients with endometriosis compared with non‐endometriotic controls. Thirteen eutopic (EuESCs) and nine ectopic (EESCs) endometrial stromal cells from endometriotic patients as well as eleven endometrial stromal cells from non‐endometriotic controls (CESCs) were treated with resveratrol (100 μmol/L) or ethanol, and gene and/or protein expression of MCP‐1, IL‐6, IL‐8 and RANTES was examined at 6, 24 and 48 hours following treatment in the cells from all origins. Resveratrol treatment significantly reduced gene and protein expression of MCP‐1, IL‐6, and IL‐8 in EuESCs and EESCs compared with CESCs (P < .05‐.001, P < .05‐.001 and P < .05‐<.01, respectively), and this reduction was more noticeable in EESCs than EuESCs (P < .05‐<.001). Besides, resveratrol treatment significantly reduced RANTES protein expression in EESCs in all time intervals (P < .05). Resveratrol treatment significantly reduced the expression of MCP‐1, IL‐6, IL‐8 and RANTES in EESCs.

Establishment of an immortalized stromal cell line derived from human Endometriotic lesion

BACKGROUND

Endometriosis is a benign gynecological disease with obviously feature of estrogen-dependence and inflammatory response. The applications of primary endometriotic stromal cells in research of endometriosis are restricted for short life span, dedifferentiation of hormone and cytokine responsiveness. The objective of this study was to establish and characterize immortalized human endometriotic stromal cells (ihESCs).

METHODS

The endometriotic samples were from a patient with ovarian endometriosis and the primary endometriotic stromal cells were isolated from the endometriotic tissues. The primary cells were infected by lentivirus to establish telomerase reverse transcriptase (hTERT)-induced immortalized cells. Quantification of mRNA and proteins was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western Blot. CCK-8 assay and EdU labeling assay were assigned to assess the growth of ihESCs. Karyotype assay was performed to detect the chromosomes of ihESCs. Colony formation assay and nude mouse tumorigenicity assay were used to evaluate colony-formation and tumorigenesis abilities.

RESULTS

ihESCs continuously overexpressed hTERT via infection of lentivirus and significant extended the life span reaching 31 passages. The morphology, proliferation and karyotype of ihESCs remained unchanged. The expression of epithelial-mesenchymal transition (EMT) markers, estrogen-metabolizing proteins and estrogen/progesterone receptors (ERs and PRs) were unaltered. Furthermore, the treatment of estrogen increased the proliferation and EMT of ihESCs. Lipopolysaccharides (LPS) and IL-1β remarkably induced inflammatory response. The clonogenesis ability of ihESCs was consistent with primary cells, which were much lower than Ishikawa cells. In addition, nude mouse tumorigenicity assay demonstrated that ihESCs were unable to trigger tumor formation.

CONCLUSION

This study established and characterized an immortalized endometriotic stromal cell line that exhibited longer life span and kept the cellular morphology and physiological function as the primary cells. The immortalized cells remained normal feedback to estrogen and inflammatory response. Moreover, the immortalized cells were not available with tumorigenic ability. Therefore, ihESCs would be serviceable as in vitro cell tool to investigate the pathogenesis of endometriosis.

Pyrvinium pamoate induces in-vitro suppression of IL-6 and IL-8 produced by human endometriotic stromal cells

Endometriosis, a chronic inflammatory disease, is identified by the presence of endometrial tissue outside the uterus. The prevalence of this disease among reproductive-age women is almost 10-15%. High levels of IL-6 and IL-8 have been found in the peritoneal fluid (PF) of women with endometriosis and are involved in its pathogenesis. Isolated stromal cells from 12 ectopic and eutopic endometrial biopsies of women with ovarian endometrioma and also 12 endometrial biopsies of nonendometriotic controls were treated with 1.1 µM pyrvinium pamoate, a Wnt/β-catenin signaling pathway inhibitor, for 72 hrs. Before treatment, mRNA gene expression and secretion of IL-6 and IL-8 were significantly higher in ectopic (EESCs) than eutopic (EuESCs) and control (CESCs) endometrial stromal cells. After treatment, mRNA gene expression and also secretion of IL-6 and IL-8 were significantly reduced. Our Findings showed that pyrvinium pamoate suppresses the mRNA gene expression and secretion of IL-6 and IL-8 in human endometriotic stromal cells. Additional investigations on this compound are required before clinical application.

The role of unfolded protein response in the pathogenesis of endometriosis: contribution of peritoneal fluid

RESEARCH QUESTION

Endoplasmic reticulum stress (ERS) is caused by the accumulation of the misfolded or unfolded proteins in the endoplasmic reticulum and induces the unfolded protein response (UPR). Peritoneal fluid is important in the pathogenesis of endometriosis. In this study, the role of UPR associated with ERS in endometriosis, and peritoneal fluid, were investigated.

DESIGN

Normal, eutopic and ectopic endometrium tissues were divided into menstrual cycle phases, and endometrial stromal cells (ESC) were treated with 10-20% concentration of control peritoneal fluid and peritoneal fluid obtained from women with endometriosis for 10, 30 and 60 min, and 24 and 48 h. The UPR signalling proteins were analysed immunohistochemically and immunocytochemically. Data were compared statistically.

RESULTS

p-IRE1 was increased in ectopic glandular and stromal cells in the early proliferative phase compared with normal and eutopic endometrium. p-PERK increased in ectopic glandular and stromal cells in the late proliferative phase compared with normal endometrium. ATF6 was increased in ectopic glandular epithelium compared with normal endometrium in the proliferative phases, versus eutopic endometrium in the late secretory phase. p-IRE1 and p-PERK were increased in high concentrations of ESC treated with peritoneal fluid obtained from women with endometriosis for 10, 30 and 60 min compared with controls. In ESC treated with peritoneal fluid from women with endometriosis, p-IRE1 decreased at 24-48 h compared with 30 min.

CONCLUSIONS

In endometriosis, UPR pathways are activated as highly dependent on cell type and phase. Also, p-PERK and p-IRE1 increased because of exposure to high-dose peritoneal fluid from women with endometriosis in stromal cells. Our findings provide a basis for further studies searching for a potential biomarker for the diagnosis of endometriosis.

The Effects of Resveratrol Treatment on Bcl-2 and Bax Gene Expression in Endometriotic Compared with Non-Endometriotic Stromal Cells

Background

We aimed to examine resveratrol effects on gene expression of Bcl-2, Bax and Bcl-2/Bax ratio in endometrial stromal cells derived from women with and without endometriosis.

Methods

Endometrial tissues were obtained from 40 endometriotic patients and 15 non-endometriotic controls undergoing laparoscopic surgery or hysterectomy in the gynecology ward of Rassoul Akram Hospital, Tehran, Iran from 2015 to 2017. After the enzymatic digestion, eutopic (EuESCs) and ectopic (EESCs) endometrial stromal cells from patients with endometriosis as well as endometrial stromal cells from non-endometriotic controls (CESCs) were treated with or without resveratrol (100 μM) and the levels of Bcl-2, Bax and Bcl-2/Bax gene expression ratio in the cells from all origins were examined at 6, 24 and 48 h post-treatment by real-time PCR.

Results

Resveratrol treatment increased Bcl-2 expression in CESCs at 24 and 48 h and in EuESCs at 48 h (P<0.05), but had no significant effects on the expression of this gene in EESCs. On the other hand, resveratrol treatment increased Bax expression in EuESCs at 6 h and decreased its expression in EESCs at 48 h (P<0.05). Regarding the Bcl-2/Bax gene expression ratio, resveratrol treatment increased Bcl-2/Bax gene expression ratio in CESCs and EuESCs at 48 h (P<0.01). However, this treatment had no significant differential effect on Bcl-2 and Bcl-2/Bax gene expression ratio between CESCs and EuESCs at 48 h.

Conclusion

Resveratrol treatment significantly increased Bcl-2/Bax gene expression ratio in EuESCs and CESCs but had no significant effect in EESCs.

Fibrinogen alpha chain promotes the migration and invasion of human endometrial stromal cells in endometriosis through focal adhesion kinase/protein kinase B/matrix metallopeptidase 2 pathway†

Fibrinogen alpha chain (FGA), a cell adhesion molecule, contains two arginyl-glycyl-aspartic acid (RGD) cell adhesion sequences. Our previous study demonstrated that FGA, as an up-regulated protein in endometriosis (EM), was closely related to disease severity and involved in the development of EM. However, the biological functions and underlying mechanism of FGA in EM have not been fully understood. To explore the roles of FGA in EM, we analyzed the effects of FGA on the biological behaviors of human primary eutopic endometrial stromal cells (EuESC). The results indicated FGA knockdown suppressed the migration and invasion ability of EuESC, which also altered the distribution of cytoskeletal filamentous and cell morphology. Western blot analysis demonstrated that knockdown of FGA attenuated the migration-related protein levels of vimentin and matrix metallopeptidase 2 (MMP-2), but not integrin subunit alpha V (ITGAV) and integrin subunit beta 3 (ITGB3). Meanwhile, integrin-linked transduction pathways were detected. We found FGA knockdown significantly suppressed the expression of focal adhesion kinase (FAK) level and protein kinase B (AKT) phosphorylation, without extracellular-signal-regulated kinase (ERK) dependent pathways. Treatment with the AKT inhibitor MK2206 or RGD antagonist highly decreased the effects of FGA on the migration and invasion of EuESC. RGD antagonist treatment strongly inhibited FAK- and AKT-dependent pathways, but not ERK pathways. Our data indicated that FGA may enhance the migration and invasion of EuESC through RGD sequences binding integrin and activating the FAK/AKT/MMP-2 signaling pathway. This novel finding suggests that FGA may provide a novel potential approach to the treatment of EM, which provides a new way to understand the pathogenesis of EM.

Endometrial stromal cell inflammatory phenotype during severe ovarian endometriosis as a cause of endometriosis-associated infertility

RESEARCH QUESTION

Do endometrial stromal cells from primary infertile patients with severe ovarian endometriosis display differential secretory profiles of inflammation-associated cytokines during the implantation window that may cause infertility?

DESIGN

Forty-eight cytokines were measured in conditioned medium of isolated endometrial stromal cells obtained from primary infertile patients without endometriosis (control group, n = 12) or with stage IV ovarian endometriosis (ovarian endometriosis group, n = 14) using multiplex assays. Key cytokines showing differential secretory profiles were validated using Western immunoblotting. Cellular phenotypic validation was carried out in vitro by comparing proliferation and migration capacity between control (n = 6) and ovarian endometriosis (n = 7) groups.

RESULTS

CCL3, CCL4, CCL5, CXCL10, FGF2, IFNG, IL1RN, IL5, TNFA, and VEGF could be detected only in the conditioned media of stromal cells obtained from the ovarian endometriosis group. Among other cytokines detected in the conditioned media of both groups, CCL2 (P = 0.0018), CSF3 (P = 0.0017), IL1B (P = 0.0066), IL4 (P = 0.036), IL6 (P = 0.0039) and IL13 (P = 0.036) were found to be higher, whereas the concentration of IL18 was lower (P = 0.023) in the ovarian endometriosis group. Concentrations of CCL2, IL1B, IL4 and IL13 in conditioned medium reflected significant diagnostic performance for predicting ovarian endometriosis. Cellular phenotypic validation in vitro revealed an enhanced proliferative phenotype (P = 0.046) with no change in cell migratory capacity of endometrial stromal cells from the ovarian endometriosis group.

CONCLUSIONS

Endometrial stromal cells derived from severe ovarian endometriosis samples displayed a hyperinflammatory and hyperproliferative bias in the endometrial stroma during the 'window of implantation' putatively causing loss of fecundability.

Evaluation of apoptosis and angiogenesis in ectopic and eutopic stromal cells of patients with endometriosis compared to non-endometriotic controls

Background

Endometriosis is a chronic, painful, and inflammatory disease characterized by extra-uterine growth of endometrial tissues. Increased angiogenesis and resistance to apoptosis have been suggested to be involved in pathogenesis and development of endometriosis. The objective of this study was to examine apoptosis potential and angiogenesis contribution of eutopic (EuESCs) and ectopic (EESCs) endometrial stromal cells in patients with endometriosis compared to endometrial stromal cells from non-endometriotic controls (CESCs).

Methods

Stromal cells were isolated by enzymatic digestion of ectopic (n = 11) and eutopic (n = 17) endometrial tissues from laparoscopically-confirmed endometriotic patients. Endometrial stromal cells of 15 non-endometriotic patients served as control. Following cell characterization by immunofluorescent staining and flow cytometry using a panel of antibodies, the total RNA was isolated from the cultured cells, and analyzed for the expression of genes involved in apoptosis (Bcl-2, Bcl-xL, Bax, and caspase-3) and angiogenesis [vascular endothelial growth factor-A (VEGF-A) and hepatocyte growth factor (HGF)] by Real-time PCR.

Results

Significantly higher gene expression levels of Bcl-2 and Bcl-xL were found in EESCs compared with EuESCs and CESCs (p < 0.01). The gene expression of Bax in EESCs, EuESCs, and CESCs was not statistically significant. Furthermore, EuESCs exhibited a significantly lower caspase-3 gene expression compared with CESCs (p < 0.01) or EESCs (p < 0.05). Regarding angiogenesis, VEGF-A gene expression in EESCs (p < 0.001) and EuESCs (p < 0.05) were significantly higher compared with those of CESCs. EESCs exhibited a significantly higher HGF gene expression compared with EuESCs (p < 0.05).

Conclusions

These findings suggest reduced propensity to apoptosis and increased angiogenesis potential of EESCs, which may be involved in pathogenesis of endometriosis.

Pyrvinium pamoate inhibits proliferation and invasion of human endometriotic stromal cells

Endometriosis is characterized by the presence of functional endometrial tissue in other pelvic organs. This gynecologic problem occurs in 35–50% of women with pain and infertility. Endometriotic cells share some characteristics such as proliferation, migration, and invasion with tumor cells. Pyrvinium pamoate, an anthelmintic drug approved by the Food and Drug Administration, could inhibit the Wnt/β-catenin signaling pathway and its anticancer effects were examined by several researchers. In this study, 12 ectopic and eutopic endometrial biopsies from females with ovarian endometrioma and 12 endometrial biopsies from nonendometriotic females were obtained. Ectopic (EESCs), eutopic (EuESCs), and control (CESCs) endometrial stromal cells were isolated. Then, the effect of pyrvinium pamoate on the proliferation and invasiveness of in vitro cultured cells was evaluated. The proliferation of CESCs, EuESCs, and EESCs was significantly decreased after treatment with pyrvinium pamoate. In addition, treatment with pyrvinium pamoate significantly inhibited the invasiveness of CESCs, EuESCs, and EESCs compared to nontreated groups. The results of the present research showed that pyrvinium pamoate inhibits the proliferation and invasion of human endometriotic stromal cells in vitro, further investigations on the therapeutic potential of this compound in endometriosis are required.

GLI1 is increased in ovarian endometriosis and regulates migration, invasion and proliferation of human endometrial stromal cells in endometriosis

BACKGROUND

Endometriosis is a benign gynecological disorder which shares certain characteristics with malignant tumor like migration, invasion and proliferation. Glioma-associated oncogene homolog 1 (GLI1) has been implicated in some cancers including endometrial cancer, however, its role in endometriosis remains unknown.

METHODS

The aim of this study was to explore the expression pattern of GLI1 in endometriosis, and further investigate the effect of GLI1 regulation on human endometrial stromal cells. The expression of GLI1 in normal endometrium and ectopic tissues was analyzed by immunohistochemistry, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot. The Short hairpin RNA (ShRNA) intervention technique and GLI1 inhibitor GANT-61 were used to silence GLI1. The expression levels of GLI1, MMP2 and MMP9 was detected by qRT-PCR and western blot. The migration and invasion ability of human endometrial stromal cells was determined by wound healing assay and transwell migration/invasion assay. The viability and proliferation potentiality of cells was detected by MTT assays and colony formation assay, respectively.

RESULTS

We found that the expression of GLI1 mRNA and protein were significantly higher in ectopic endometrium from patients with endometriosis. Our analyses also show that GLI1 downregulation attenuated cells migration, invasion and proliferation abilities. What's more, reduced expression of GLI1 inhibited the expression of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9).

CONCLUSIONS

Our findings suggest that high levels of GLI1 may contribute to the development of endometriosis by promoting cell migration, invasion and proliferation involving regulation of MMP2 and MMP9 expression. Therefore, inhibition of GLI1 might be a novel potential therapeutic approach to the treatment of endometriosis, which sheds new light on our understanding of the pathogenesis of endometriosis.

Eutopic endometrium from patients with endometriosis modulates the expression of CD36 and SIRP-α in peritoneal macrophages

Aim

This study aimed to investigate the in vitro alterations of the expression of signal regulatory protein‐α (SIRP‐α) and CD36 in macrophages in the endometriosis condition.

Methods

The expression of SIRP‐α and CD36 was measured in peritoneal macrophages and peripheral blood mononuclear cells of endometriosis patients and control participants. The expressions of SIRP‐α and CD36 were measured in human acute monocytic leukemia (THP‐1) cell‐derived macrophages that were treated with interleukin‐6 (IL‐6)‐induced conditioned medium, eutopic versus normal endometrial homogenate, or lipopolysaccharide in the presence or absence of nuclear factor kappa‐B (NF‐κB) or transforming growth factor (TGF‐β) inhibitors, respectively.

Results

Peritoneal macrophages that were isolated from women with endometriosis exhibited an enhanced expression of SIRP‐α and a decreased expression of CD36 compared to control participants. Women with endometriosis had significantly higher levels of SIRP‐α and CD36 in peripheral circulating mononuclear cells than in control participants. SIRP‐α expression was significantly increased, whereas the CD36 expression was decreased in THP‐1 cell‐derived macrophages after treatment with eutopic endometrial homogenate. Intervention with IL‐6‐induced conditioned medium resulted in the downregulation of SIRP‐α but the upregulation of CD36 in THP‐1 cells. Incubation with the NF‐κBp50 inhibitor decreased the expression of CD36 and SIRP‐α in macrophages that were treated with normal endometrial homogenate, whereas the TGF‐β inhibitor enhanced the CD36 expression of THP‐1 cell‐derived macrophages treated with eutopic endometrial homogenate.

Conclusion

The eutopic endometrium could reduce the phagocytic ability of peritoneal macrophages in women with endometriosis through the modulation of SIRP‐α and CD36 expression. Inhibition of the TGF‐β signal pathway may be a potential therapeutic target for the treatment of endometriosis.

Resveratrol reduces the expression of insulin-like growth factor-1 and hepatocyte growth factor in stromal cells of women with endometriosis compared with nonendometriotic women

Resveratrol, a phytoalexin polyphenol, has antiproliferative, antiangiogenic, anti-inflammatory, and antioxidant properties. The present study has assessed the effect of resveratrol treatment on the expression of insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) in endometrial stromal cells (ESCs) from women with and without endometriosis. Endometrial tissues were obtained from 40 endometriotic patients and 15 nonendometriotic control women. After the enzymatic digestion, 13 eutopic ESCs (EuESCs), 8 ectopic ESCs (EESCs), and 11 control ESCs (CESCs) were treated with resveratrol (100 μM) for 6, 24, and 48 hr. The gene and protein expressions of IGF-1 and HGF were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay methods, respectively. Results showed that resveratrol treatment decreased significantly the gene expression of IGF-1 and HGF in EuESCs, EESCs, and CESCs (p < 0.05). The effect of resveratrol treatment on the reduction of IGF-1 gene expression was statistically more noticeable in EESCs compared with CESCs (p < 0.05). Also, in the case of HGF gene expression, the reducing effect of resveratrol treatment was statistically more considerable in EESCs compared with EuESCs and CESCs (p < 0.05 and p < 0.01, respectively). The IGF-1 and HGF protein production decreased significantly in EuESCs and EESCs (p < 0.05) but not in CESCs. These findings suggest that resveratrol treatment could reduce the expression of IGF-1 and HGF in ESCs especially in EESCs, which play a pivotal role in disease progression.

Targeting Anthrax Toxin Receptor 2 Ameliorates Endometriosis Progression

Rationale: Endometriosis is a highly prevalent gynecological disease in women of reproductive age that markedly reduces life quality and fertility. Unfortunately, there is no cure for this disease, which highlights that more efforts are needed to investigate the underlying mechanism for designing novel therapeutic regimens. This study aims to investigate druggable membrane receptors distinctively expressed in endometriotic cells. Methods: Bioinformatic analysis of public databases was employed to identify potential druggable candidates. Normal endometrial tissues and ectopic endometriotic lesions were obtained for the determination of target genes. Primary endometrial and endometriotic stromal cells as well as two different mouse models of endometriosis were used to characterize molecular mechanisms and therapeutic outcomes of endometriosis, respectively. Results: Anthrax toxin receptor 2 (ANTXR2) mRNA and protein are upregulated in the endometriotic specimens. Elevation of ANTXR2 promotes endometriotic cell adhesion, proliferation, and angiogenesis. Furthermore, hypoxia is the driving force for ANTXR2 upregulation via altering histone modification of ANTXR2 promoter by reducing the repressive mark, histone H3 lysine 27 (H3K27) trimethylation, and increasing the active mark, H3K4 trimethylation. Activation of ANTXR2 signaling leads to increased Yes-associated protein 1 (YAP1) nuclear translocation and transcriptional activity, which contributes to numerous pathological processes of endometriosis. Pharmacological blocking of ANTXR2 signaling not only prevents endometriotic lesion development but also causes the regression of established lesion. Conclusion: Taken together, we have identified a novel target that contributes to the disease pathogenesis of endometriosis and provided a potential therapeutic regimen to treat it.

Hypoxia Promotes Ectopic Adhesion Ability of Endometrial Stromal Cells via TGF-β1/Smad Signaling in Endometriosis

Hypoxia plays a vital role in the progression of endometriosis. Additionally, integrin-mediated aberrant adhesion is also essential for establishment of endometriotic lesions. In this study, we sought to determine the function of hypoxia in integrin-mediated adhesion of endometrial stromal cells (ESCs) in endometriosis. The expressions of adhesion molecule integrins (integrin α5, integrin αV, integrin β3, and integrin β5) were determined in 15 normal endometria and 15 paired eutopic and ectopic endometria by immunohistochemistry. Thirteen primary ESCs from patients with peritoneal endometriosis in the proliferative phase were cultured under a hypoxic (1% O2) or normoxic (21% O2) environment, and the expression levels of hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β1, and integrins were detected by quantitative reverse transcription polymerase chain reaction and western blot. The alteration of integrins in endometriotic mouse models were also explored. Our results demonstrated that HIF-1α and integrins were highly expressed in ESCs of endometriotic lesions compared with ESCs of eutopic and normal endometrium. Hypoxia treatment significantly increased ESC adhesion abilities and integrin expression, which were positively correlated with TGF-β1 expression. Both TGF-β1 and hypoxia enhanced ESC adhesion properties, whereas hypoxia combined with TGF-β1 receptor inhibitor inhibited ESC adhesion. Knockdown of HIF-1α attenuated TGF-β1/Smad signaling activation and integrin expression and reduced ESC adhesion. Higher expression levels of HIF-1α, TGF-β1, and integrins were detected in endometriotic cysts from mice models. Our findings provide a novel insight of endometriosis that the hypoxic microenvironment stimulates ESCs to produce excessive TGF-β1 and activates the TGF-β1/Smad signaling pathway, thus enhancing integrin expression and the adhesion ability of ESCs.

Expression and shedding of CD44 in the endometrium of women with endometriosis and modulating effects of vitamin D: A randomized exploratory trial

Endometriosis is an estrogen-dependent disease. The impaired estrogen and progesterone signaling over-activates the Wnt/β-catenin pathway in endometriosis patients, which can explain the increased invasion potency of endometrial cells derived from the endometrium of women with endometriosis. The regulatory effects of vitamin D on Wnt/β-catenin pathway were demonstrated by previous studies. According to gene prioritization method, among Wnt target genes, CD44 was in high ranking in relation to endometriosis. The aim of this study is to investigate the expression of CD44 in the endometrium of women with endometriosis and to study the effects of vitamin D on its expression. This prospective study was performed, during a 12 months period from December 2015 to November 2016, on healthy women as the control group (n = 14) and endometriosis patients (n = 34). The endometriosis patients randomly divided into two groups: One group treated according to the routine protocol and the other group, alongside the routine protocol, took 50,000 IU vitamin D weekly for 12-14 weeks. Blood, endometrial fluid, and endometrial tissue samples were obtained from the control group and endometriosis groups before and after the intervention. We used in silico gene prioritization to study the relevance of CD44. The expression of CD44 was evaluated using the techniques of Western blot, real-time polymerase chain reaction, and ELISA. The eutopic endometrium of women with endometriosis in mid-secretory phase expressed significantly higher levels of CD44s, CD44V, and CD44v6. The concentration of soluble CD44 in the serum and endometrial fluid of endometriosis patients was higher than of healthy women. The expression level of CD44s, CD44V, and CD44v6 in the eutopic endometrium as well as the concentration of soluble CD44 in the endometrial fluid was decreased after modification of the circulating levels of 25(OH)D. It seems that the increased expression and extensive shedding of CD44 in eutopic endometrium play a role in the pathogenesis of endometriosis. Vitamin D can control and modify this process at least in part. We suggest more in vivo investigations on the therapeutic potency of vitamin D in endometriosis.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Wenshen 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 METHODS

Primary 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.

RESULTS

WXT 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.

CONCLUSIONS

Our results indicate that WXT induces apoptosis and inhibits migration of ectopic endometriotic stromal cells.

Co-micronized Palmitoylethanolamide/Polydatin Treatment Causes Endometriotic Lesion Regression in a Rodent Model of Surgically Induced Endometriosis

Endometriosis is a chronic, painful disease characterized by the presence of endometrial glands and stroma outside the uterine cavity. Palmitoylethanolamide (PEA), an endogenous fatty acid amide, has anti-inflammatory and neuroprotective effects. PEA lacks free radical scavenging activity, unlike polydatin (PLD), a natural precursor of resveratrol. The aim of this study was to investigate the effect of orally administered co-micronized PEA/polydatin [m(PEA/PLD)] in an autologous rat model of surgically induced endometriosis. Endometriosis was induced in female Wistar albino rats by auto-transplantation of uterine squares (implants) into the intestinal mesentery and peritoneal cavity. Rats were distributed into one control group and one treatment group (10 animals each): m(PEA/PLD) 10 mg/kg/day. At 28 days after surgery the relative volume of the endometrioma was determined. Endometrial-like tissue was confirmed by histology: Masson trichrome and toluidine blue were used to detect fibrosis and mast cells, respectively. The treated group displayed a smaller cyst diameter, with improved fibrosis score and mast cell number decrease. m(PEA/PLD) administration decreased angiogenesis (vascular endothelial growth factor), nerve growth factor, intercellular adhesion molecule, matrix metalloproteinase 9 expression, and lymphocyte accumulation. m(PEA/PLD) treatment also reduced peroxynitrite formation, (poly-ADP)ribose polymerase activation, IkBα phosphorylation and nuclear facor-kB traslocation in the nucleus. Our results suggested that m(PEA/PLD) may be of use to inhibit development of endometriotic lesions in rats.

Endometriosis: where are we and where are we going?

Endometriosis currently affects ~5.5 million reproductive-aged women in the U.S. with symptoms such as painful periods (dysmenorrhea), chronic pelvic pain, pain with intercourse (dyspareunia), and infertility. It is defined as the presence of endometrial tissue outside the uterine cavity and is found predominately attached to sites within the peritoneal cavity. Diagnosis for endometriosis is solely made through surgery as no consistent biomarkers for disease diagnosis exist. There is no cure for endometriosis and treatments only target symptoms and not the underlying mechanism(s) of disease. The nature of individual predisposing factors or inherent defects in the endometrium, immune system, and/or peritoneal cavity of women with endometriosis remains unclear. The literature over the last 5 years (2010-2015) has advanced our critical knowledge related to hormones, hormone receptors, immune dysregulation, hormonal treatments, and the transformation of endometriosis to ovarian cancer. In this review, we cover the aforementioned topics with the goal of providing the reader an overview and related references for further study to highlight the progress made in endometriosis research, while concluding with critical areas of endometriosis research that are urgently needed.

Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells

Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2–30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production.

Endometrial biomarkers for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of reproductive-aged women suffer from endometriosis, which is a costly, chronic disease that causes pelvic pain and subfertility. Laparoscopy is the gold standard diagnostic test for endometriosis, but it is expensive and carries surgical risks. Currently, there are no non-invasive tests available in clinical practice that accurately diagnose endometriosis. This is the first diagnostic test accuracy review of endometrial biomarkers for endometriosis that utilises Cochrane methodologies, providing an update on the rapidly expanding literature in this field.

OBJECTIVES

To determine the diagnostic accuracy of the endometrial biomarkers for pelvic endometriosis, using a surgical diagnosis as the reference standard. We evaluated the tests as replacement tests for diagnostic surgery and as triage tests to inform decisions to undertake surgery for endometriosis.

SEARCH METHODS

We did not restrict the searches to particular study designs, language or publication dates. To identify trials, we searched the following databases: CENTRAL (2015, July), MEDLINE (inception to May 2015), EMBASE (inception to May 2015), CINAHL (inception to April 2015), PsycINFO (inception to April 2015), Web of Science (inception to April 2015), LILACS (inception to April 2015), OAIster (inception to April 2015), TRIP (inception to April 2015) and ClinicalTrials.gov (inception to April 2015). We searched DARE and PubMed databases up to April 2015 to identify reviews and guidelines as sources of references to potentially relevant studies. We also performed searches for papers recently published and not yet indexed in the major databases. The search strategies incorporated words in the title, abstract, text words across the record and the medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed, randomised controlled or cross-sectional studies of any size that included prospectively collected samples from any population of reproductive-aged women suspected of having one or more of the following target conditions: ovarian, peritoneal or deep infiltrating endometriosis (DIE).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from each study and performed a quality assessment. For each endometrial diagnostic test, we classified the data as positive or negative for the surgical detection of endometriosis and calculated the estimates of sensitivity and specificity. We considered two or more tests evaluated in the same cohort as separate data sets. We used the bivariate model to obtain pooled estimates of sensitivity and specificity whenever sufficient data were available. The predetermined criteria for a clinically useful test to replace diagnostic surgery was one with a sensitivity of 94% and a specificity of 79%. The criteria for triage tests were set at sensitivity at or above 95% and specificity at or above 50%, which in case of negative results rules out the diagnosis (SnOUT test) or sensitivity at or above 50% with specificity at or above 95%, which in case of positive result rules in the diagnosis (SpIN test).

MAIN RESULTS

We included 54 studies involving 2729 participants, most of which were of poor methodological quality. The studies evaluated endometrial biomarkers either in specific phases of the menstrual cycle or outside of it, and the studies tested the biomarkers either in menstrual fluid, in whole endometrial tissue or in separate endometrial components. Twenty-seven studies evaluated the diagnostic performance of 22 endometrial biomarkers for endometriosis. These were angiogenesis and growth factors (PROK-1), cell-adhesion molecules (integrins α3β1, α4β1, β1 and α6), DNA-repair molecules (hTERT), endometrial and mitochondrial proteome, hormonal markers (CYP19, 17βHSD2, ER-α, ER-β), inflammatory markers (IL-1R2), myogenic markers (caldesmon, CALD-1), neural markers (PGP 9.5, VIP, CGRP, SP, NPY, NF) and tumour markers (CA-125). Most of these biomarkers were assessed in single studies, whilst only data for PGP 9.5 and CYP19 were available for meta-analysis. These two biomarkers demonstrated significant diversity for the diagnostic estimates between the studies; however, the data were too limited to reliably determine the sources of heterogeneity. The mean sensitivities and specificities of PGP 9.5 (7 studies, 361 women) were 0.96 (95% confidence interval (CI) 0.91 to 1.00) and 0.86 (95% CI 0.70 to 1.00), after excluding one outlier study, and for CYP19 (8 studies, 444 women), they were were 0.77 (95% CI 0.70 to 0.85) and 0.74 (95% CI 0.65 to 84), respectively. We could not statistically evaluate other biomarkers in a meaningful way. An additional 31 studies evaluated 77 biomarkers that showed no evidence of differences in expression levels between the groups of women with and without endometriosis.

AUTHORS' CONCLUSIONS

We could not statistically evaluate most of the biomarkers assessed in this review in a meaningful way. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Although PGP 9.5 met the criteria for a replacement test, it demonstrated considerable inter study heterogeneity in diagnostic estimates, the source of which could not be determined. Several endometrial biomarkers, such as endometrial proteome, 17βHSD2, IL-1R2, caldesmon and other neural markers (VIP, CGRP, SP, NPY and combination of VIP, PGP 9.5 and SP) showed promising evidence of diagnostic accuracy, but there was insufficient or poor quality evidence for any clinical recommendations. Laparoscopy remains the gold standard for the diagnosis of endometriosis, and using any non-invasive tests should only be undertaken in a research setting. We have also identified a number of biomarkers that demonstrated no diagnostic value for endometriosis. We recommend that researchers direct future studies towards biomarkers with high diagnostic potential in good quality diagnostic studies.

LPS/TLR4-mediated stromal cells acquire an invasive phenotype and are implicated in the pathogenesis of adenomyosis

The present study tested whether the LPS/TLR4 signal pathway in endometrial stromal cells is essential for the pathogenesis of adenomyosis. We tested the expression of TLR4, MD2 in the endometrium without adenomyosis (CE), the eutopic endometrium with adenomyosis (EuE) and the ectopic endometrium with adenomyosis (EE). We isolated the stromal cells from CE, EuE and EE (CESC, EuESC, EESC), treated with lipopolysaccharide (LPS) and TLR4 antagonist and detected the cell viability. And we also measured the key protein of the TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells. We found that the viability of experimental cells treated with LPS was significantly greater than that of the non-treated cells, blocked by the TLR4 antagonist VIPER. TLR4 signal pathway and inflammatory proliferation and invasive growth of experimental cells stimulated by LPS, and it was inhibited by VIPER. This study suggested that stromal cells were activated by the TLR4 signalling pathway, which processed the cellular inflammatory proliferation and invasive growth involved in the pathogenesis of adenomyosis.

The oil-resin of the tropical rainforest tree Copaifera langsdorffii reduces cell viability, changes cell morphology and induces cell death in human endometriotic stromal cultures

OBJECTIVES

The hormonal treatment for endometriosis frequently fails to completely eradicate endometriotic implants. A new therapeutic treatment is needed. This study investigates the in-vitro effect of Copaifera langsdorffii oil-resin on human eutopic and ectopic endometrium stromal cell cultures (EuESCs and EctESCs).

METHODS

A nanocomposite system containing the copaiba oil-resin (NanoCOR) was developed and acute toxicity test was performed. Endometrial stromal cells (ESCs) from non-endometriotics controls (CESCs), EuESCs and EctESCs were isolated and treated with different concentrations of NanoCOR, at different time intervals to evaluate its effect on cell morphology, proliferation, viability, necrosis and apoptosis induction.

KEY FINDINGS

When treated with 50 μg/ml of NanoCOR, the morphology of EctESCs changed, as the actin microfilaments were disorganized, disassembled or disrupted. Moreover, at 24 h of treatment with NanoCOR, the EctESCs viability was inhibited, and a significant number of these cells underwent apoptosis. In EuESCs, these effects were observed only at 48 h. Finally, the treatment of EctESCs with NanoCOR increased the lactate dehydrogenase release into the extracellular medium more than in EuESCs.

CONCLUSIONS

Our data indicate that NanoCOR has a greater impact on the behaviour of human endometriotic stromal cells than on the eutopic endometrium stromal cells, supporting the idea that NanoCOR should be further investigated as a novel and valuable alternative to treat endometriosis.