Promotion of angiogenesis and proliferation cytokines patterns in peritoneal fluid from women with endometriosis

An integrated multi-tissue approach for endometriosis candidate biomarkers: a systematic review

Biomarker identification could help in deciphering endometriosis pathophysiology in addition to their use in the development of non invasive diagnostic and prognostic approaches, that are essential to greatly improve patient care. Despite extensive efforts, no single potential biomarker or combination has been clinically validated for endometriosis.Many studies have investigated endometriosis-associated biological markers in specific tissues, but an integrative approach across tissues is lacking. The aim of this review is to propose a comprehensive overview of identified biomarkers based on tissue or biological compartment, while taking into account endometriosis phenotypes (superficial, ovarian or deep, or rASRM stages), menstrual cycle phases, treatments and symptoms.We searched PubMed and Embase databases for articles matching the following criteria: 'endometriosis' present in the title and the associated term 'biomarkers' found as Medical Subject Headings (MeSH) terms or in all fields. We restricted to publications in English and on human populations. Relevant articles published between 01 January 2005 (when endometriosis phenotypes start to be described in papers) and 01 September 2022 were critically analysed and discussed.Four hundred forty seven articles on endometriosis biomarkers that included a control group without endometriosis and provided specific information on endometriosis phenotypes are included in this review. Presence of information or adjustment controlling for menstrual cycle phase, symptoms and treatments is highlighted, and the results are further summarized by biological compartment. The 9 biological compartments studied for endometriosis biomarker research are in order of frequency: peripheral blood, eutopic endometrium, peritoneal fluid, ovaries, urine, menstrual blood, saliva, feces and cervical mucus. Adjustments of results on disease phenotypes, cycle phases, treatments and symptoms are present in 70%, 29%, 3% and 6% of selected articles, respectively. A total of 1107 biomarkers were identified in these biological compartments. Of these, 74 were found in several biological compartments by at least two independent research teams and only 4 (TNF-a, MMP-9, TIMP-1 and miR-451) are detected in at least 3 tissues with cohorts of 30 women or more.Integrative analysis is a crucial step to highlight potential pitfalls behind the lack of success in the search for clinically relevant endometriosis biomarkers, and to illuminate the physiopathology of this disease.

Construction and evaluation of endometriosis diagnostic prediction model and immune infiltration based on efferocytosis-related genes

Background: Endometriosis (EM) is a long-lasting inflammatory disease that is difficult to treat and prevent. Existing research indicates the significance of immune infiltration in the progression of EM. Efferocytosis has an important immunomodulatory function. However, research on the identification and clinical significance of efferocytosis-related genes (EFRGs) in EM is sparse. Methods: The EFRDEGs (differentially expressed efferocytosis-related genes) linked to datasets associated with endometriosis were thoroughly examined utilizing the Gene Expression Omnibus (GEO) and GeneCards databases. The construction of the protein-protein interaction (PPI) and transcription factor (TF) regulatory network of EFRDEGs ensued. Subsequently, machine learning techniques including Univariate logistic regression, LASSO, and SVM classification were applied to filter and pinpoint diagnostic biomarkers. To establish and assess the diagnostic model, ROC analysis, multivariate regression analysis, nomogram, and calibration curve were employed. The CIBERSORT algorithm and single-cell RNA sequencing (scRNA-seq) were employed to explore immune cell infiltration, while the Comparative Toxicogenomics Database (CTD) was utilized for the identification of potential therapeutic drugs for endometriosis. Finally, immunohistochemistry (IHC) and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were utilized to quantify the expression levels of biomarkers in clinical samples of endometriosis. Results: Our findings revealed 13 EFRDEGs associated with EM, and the LASSO and SVM regression model identified six hub genes (ARG2, GAS6, C3, PROS1, CLU, and FGL2). Among these, ARG2, GAS6, and C3 were confirmed as diagnostic biomarkers through multivariate logistic regression analysis. The ROC curve analysis of GSE37837 (AUC = 0.627) and GSE6374 (AUC = 0.635), along with calibration and DCA curve assessments, demonstrated that the nomogram built on these three biomarkers exhibited a commendable predictive capacity for the disease. Notably, the ratio of nine immune cell types exhibited significant differences between eutopic and ectopic endometrial samples, with scRNA-seq highlighting M0 Macrophages, Fibroblasts, and CD8 Tex cells as the cell populations undergoing the most substantial changes in the three biomarkers. Additionally, our study predicted seven potential medications for EM. Finally, the expression levels of the three biomarkers in clinical samples were validated through RT-qPCR and IHC, consistently aligning with the results obtained from the public database. Conclusion: we identified three biomarkers and constructed a diagnostic model for EM in this study, these findings provide valuable insights for subsequent mechanistic research and clinical applications in the field of endometriosis.

Distinct molecular targets of ProEGCG from EGCG and superior inhibition of angiogenesis signaling pathways for treatment of endometriosis

Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus. Angiogenesis is a major pathophysiology in endometriosis. Our previous studies have demonstrated that the prodrug of epigallocatechin gallate (ProEGCG) exhibits superior anti-endometriotic and anti-angiogenic effects compared to epigallocatechin gallate (EGCG). However, their direct binding targets and underlying mechanisms for the differential effects remain unknown. In this study, we demonstrated that oral ProEGCG can be effective in preventing and treating endometriosis. Additionally, 1D and 2D Proteome Integral Solubility Alteration assay-based chemical proteomics identified metadherin (MTDH) and PX domain containing serine/threonine kinase-like (PXK) as novel binding targets of EGCG and ProEGCG, respectively. Computational simulation and BioLayer interferometry were used to confirm their binding affinity. Our results showed that MTDH-EGCG inhibited protein kinase B (Akt)-mediated angiogenesis, while PXK-ProEGCG inhibited epidermal growth factor (EGF)-mediated angiogenesis via the EGF/hypoxia-inducible factor (HIF-1a)/vascular endothelial growth factor (VEGF) pathway. In vitro and in vivo knockdown assays and microvascular network imaging further confirmed the involvement of these signaling pathways. Moreover, our study demonstrated that ProEGCG has superior therapeutic effects than EGCG by targeting distinct signal transduction pathways and may act as a novel antiangiogenic therapy for endometriosis.

The Presence of Pre-Existing Endometriotic Lesions Promotes the Growth of New Lesions in the Peritoneal Cavity

Endometriosis is a common gynecological disease which is characterized by endometriotic lesions outside the uterine cavity. In this study, we investigated whether the presence of pre-existing endometriotic lesions promotes the development of new lesions due to the exchange of cells and an altered peritoneal environment. For this purpose, uterine tissue samples from FVB/N wild-type donor mice were transplanted simultaneously or time-delayed with samples from transgenic FVB-Tg(CAG-luc-GFP)L2G85Chco/J donor mice into the abdominal cavity of FVB/N wild-type recipient mice. The formation of endometriotic lesions was analyzed by means of high-resolution ultrasound, bioluminescence imaging, histology and immunohistochemistry. Moreover, immune cells and inflammatory factors in the peritoneal fluid were assessed by flow cytometry and a cytokine array. These analyses revealed that the growth of newly developing endometriotic lesions is promoted by the presence of pre-existing ones. This is not due to an exchange of cells between both lesion types but rather caused by peritoneal inflammation induced by already established lesions. These findings indicate that, among other pathogenic mechanisms, the chronic nature of endometriosis may be driven by a lesion-induced inflammatory milieu in the peritoneal cavity, which creates favorable conditions for the development of new lesions.

Synergy between Th1 and Th2 responses during endometriosis: A review of current understanding

Endometriosis is widely perceived as an estrogen-dependent chronic disorder with infertility and pelvic pain. Although the etiology of endometriosis has remained elusive, many studies have proclaimed the relevance of immune system disorders with endometriosis. With the discovery that the dysregulation of multiple biological functions in endometriosis is caused by the aberrant differentiation of T helper cells, a shift towards Th2 immune response may account for the disease progression. This review attempts to present mechanisms of cytokines, chemokines, signal pathways, transcription factors and some other factors related with the derivation of Th1/Th2 immune response involved in the development of endometriosis. The current understanding of treatment approaches and potential therapeutic targets will also be outlined with brief discussion.

Aberrant epigenetic regulation of estrogen and progesterone signaling at the level of endometrial/endometriotic tissue in the pathomechanism of endometriosis

Endometriosis is a term referring to a condition whereby the endometrial tissue is found outside the uterine cavity. This progressive and debilitating condition affects up to 15% of women of reproductive age. Due to the fact that endometriosis cells may express estrogen receptors (ERα, Erβ, GPER) and progesterone (P4) receptors (PR-A, PR-B), their growth, cyclic proliferation, and breakdown are similar to the processes occurring in the endometrium. The underlying etiology and pathogenesis of endometriosis are still not fully explained. The retrograde transport of viable menstrual endometrial cells with the retained ability to attach within the pelvic cavity, proliferate, differentiate and invade into the surrounding tissue explains the most widely accepted implantation theory. Endometrial stromal cells (EnSCs) with clonogenic potential constitute the most abundant population of cells within endometrium that resemble the properties of mesenchymal stem cells (MSCs). Accordingly, formation of the endometriotic foci in endometriosis may be due to a kind of EnSCs dysfunction. Increasing evidence indicates the underestimated role of epigenetic mechanisms in the pathogenesis of endometriosis. Hormone-mediated epigenetic modifications of the genome in EnSCs or even MSCs were attributed an important role in the etiopathogenesis of endometriosis. The roles of excess estrogen exposure and P4 resistance were also found to be crucial in the development of epigenetic homeostasis failure. Therefore, the aim of this review was to consolidate the current knowledge regarding the epigenetic background of EnSCs and MSCs and the changed properties due to estrogen/P4 imbalances in the context of the etiopathogenesis of endometriosis.

GPR30-mediated non-classic estrogen pathway in mast cells participates in endometriosis pain via the production of FGF2

Pain is one of the main clinical symptoms of endometriosis, but its underlying mechanism is still not clear. Recent studies have shown that the secretory mediators of mast cells activated by estrogen are involved in the pathogenesis of endometriosis-related pain, but how estrogen-induced mast cell mediators are involved in endometriosis-related pain remains unclear. Here, mast cells were found to be increased in the ovarian endometriotic lesions of patients. They were also closely located closely to the nerve fibers in the ovarian endometriotic lesions from of patients with pain symptoms. Moreover, fibroblast growth factor 2 (FGF2)-positive mast cells were upregulated in endometriotic lesions. The concentration of FGF2 in ascites and the protein level of fibroblast growth factor receptor 1 (FGFR1) were higher in patients with endometriosis than in those without endometriosis, and they were correlated with pain symptoms. In vitro, estrogen could promote the secretion of FGF2 through G-protein-coupled estrogen receptor 30 (GPR30) via the MEK/ERK pathway in rodent mast cells. Estrogen-stimulated mast cells enhanced the concentration of FGF2 in endometriotic lesions and aggravated endometriosis-related pain in vivo. Targeted inhibition of the FGF2 receptor significantly restrained the neurite outgrowth and calcium influx in dorsal root ganglion (DRG) cells. Administration of FGFR1 inhibitor remarkably elevated the mechanical pain threshold (MPT) and prolonged the heat source latency (HSL) in a rat model of endometriosis. These results suggested that the up-regulated production of FGF2 by mast cells through non-classic estrogen receptor GPR30 plays a vital role in the pathogenesis of endometriosis-related pain.

Network pharmacology and experimental validation to explore the potential mechanism of Sanjie Zhentong Capsule in endometriosis treatment

PURPOSE

Sanjie Zhentong Capsule (SZC) is gradually becoming widely used in the treatment of endometriosis (EMs) and has demonstrated an excellent curative effect in the clinic. However, the active components and mechanisms of Sanjie Zhentong Capsule (SZC) in the treatment of endometriosis (EMs) remain unclear, and further research is needed to explore the effects of Sanjie Zhentong Capsule (SZC).

MATERIALS AND METHODS

First, a drug target database of Sanjie Zhentong capsule (SZC) was established by consulting the TCMSP database and related literature. An endometriosis (EMs) disease target database was then established by consulting the GeneCards, OMIM and Drug Bank databases. The overlapping genes of SZC and EMs were determined, and protein-protein interactions (PPIs), gene ontology (GO) and Kyoto Gene and Genome Encyclopedia (KEGG) analyses were performed to predict the potential therapeutic mechanisms. Molecular docking was used to observe whether the key active ingredients and targets predicted by network pharmacology had good binding energy. Finally, in vitro experiments such as CCK-8, flow cytometry and RT-PCR assays were carried out to preliminarily verify the potential mechanisms.

RESULTS

Through the construction of a pharmacological network, we identified a total of 28 active components in SZC and 52 potential therapeutic targets. According to GO and KEGG enrichment analyses, the effects of SZC treatment may be related to oxidative stress, steroid metabolism, apoptosis and proliferation. We also experimentally confirmed that SZC can regulate the expression of steroid hormone biosynthesis-related genes, inhibit ectopic endometrial stromal cell (EESC) proliferation and oxidative stress, and promote apoptosis.

CONCLUSION

This study explored the potential mechanism of SZC in the treatment of EMs through network pharmacology and experiments, providing a basis for further future research on SZC in the treatment of EMs.

Endometriosis Stem Cells as a Possible Main Target for Carcinogenesis of Endometriosis-Associated Ovarian Cancer (EAOC)

Endometriosis is a serious recurrent disease impairing the quality of life and fertility, and being a risk for some histologic types of ovarian cancer defined as endometriosis-associated ovarian cancers (EAOC). The presence of stem cells in the endometriotic foci could account for the proliferative, migrative and angiogenic activity of the lesions. Their phenotype and sources have been described. The similarly disturbed expression of several genes, miRNAs, galectins and chaperones has been observed both in endometriotic lesions and in ovarian or endometrial cancer. The importance of stem cells for nascence and sustain of malignant tumors is commonly appreciated. Although the proposed mechanisms promoting carcinogenesis leading from endometriosis into the EAOC are not completely known, they have been discussed in several articles. However, the role of endometriosis stem cells (ESCs) has not been discussed in this context. Here, we postulate that ESCs may be a main target for the carcinogenesis of EAOC and present the possible sequence of events resulting finally in the development of EAOC.

Bioinformatics identification and validation of biomarkers and infiltrating immune cells in endometriosis

Background

Endometriosis (EM) is a common gynecological disorder that often leads to irregular menstruation and infertility. The pathogenesis of EM remains unclear and delays in diagnosis are common. Thus, it is urgent to explore potential biomarkers and underlying molecular mechanisms for EM diagnosis and therapies.

Methods

Three EM-related datasets (GSE11691, GSE25628, and GSE86534) were downloaded from the Gene Expression Omnibus (GEO) which were integrated into a combined dataset after removing batch effect. Differentially expressed immune cell-related genes were obtained by CIBERSORT, WGCNA, and the identification of differentially expressed genes. Random forest model (RF), support vector machine model (SVM), and generalized linear model (GLM) were then constructed and the biomarkers for EM were determined. A nomogram evaluating the risk of disease was constructed and the validity was assessed by the calibration curve, DCA curve, and clinical impact curve. Single-gene Gene Set Enrichment Analysis (GSEA)was performed to explore the molecular mechanisms of biomarkers. The ceRNA regulatory network of biomarkers was created by Cytoscape and potential target drugs were obtained in the DGIdb database (Drug-Gene Interaction database).The expression levels of biomarkers from clinical samples was quantified by RT-qPCR.

Results

The ratio of eight immune cells was significantly different between the eutopic and ectopic endometrium samples. A total of eight differentially expressed immune cell-related genes were investigated. The SVM model was a relatively suitable model for the prediction of EM and five genes (CXCL12, PDGFRL, AGTR1, PTGER3, and S1PR1) were selected from the model as biomarkers. The calibration curve, DCA curve, and clinical impact curve indicated that the nomogram based on the five biomarkers had a robust ability to predict disease. Single gene GSEA result suggested that all five biomarkers were involved in labyrinthine layer morphogenesis and transmembrane transport-related biological processes in EM. A ceRNA regulatory network containing 184 nodes and 251 edges was constructed. Seven drugs targeting CXCL12, 49 drugs targeting AGTR1, 16 drugs targeting PTGER3, and 21 drugs targeting S1PR1 were extracted as potential drugs for EM therapy. Finally, the expression of PDGFRL and S1PR1 in clinical samples was validated by RT-qPCR, which was consistent with the result of public database.

Conclusions

In summary, we identified five biomarkers (CXCL12, PDGFRL, AGTR1, PTGER3, and S1PR1) and constructed diagnostic model, furthermore predicted the potential therapeutic drugs for EM. Collectively, these findings provide new insights into EM diagnosis and treatment.

Invariant Natural Killer T-cells and their subtypes may play a role in the pathogenesis of endometriosis

OBJECTIVE

To evaluate the frequencies of iNKT cells and their subsets in patients with deep endometriosis.

METHODS

A case-control study was conducted between 2013 and 2015, with 73 patients distributed into two groups: 47 women with a histological diagnosis of endometriosis and 26 controls. Peripheral blood, endometriosis lesions, and healthy peritoneal samples were collected on the day of surgery to determine the frequencies of iNKT cells and subtypes via flow cytometry analysis.

RESULTS

The authors observed a lower number of iNKT (p = 0.01) and Double-Negative (DN) iNKT cells (p = 0.02) in the blood of patients with endometriosis than in the control group. The number of DN iNKT IL-17+ cells in the secretory phase was lower in the endometriosis group (p = 0.049). There was an increase in the secretion of IL-17 by CD4+ iNKT cells in the blood of patients with endometriosis and severe dysmenorrhea (p = 0.038), and severe acyclic pelvic pain (p = 0.048). Patients with severe dysmenorrhea also had a decreased number of CD4+ CCR7+ cells (p = 0.022).

CONCLUSION

The decreased number of total iNKT and DN iNKT cells in patients with endometriosis suggests that iNKT cells play a role in the pathogenesis of endometriosis and can be used to develop new diagnostic and therapeutic agents.

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.

The Role of Selected Chemokines in the Peritoneal Fluid of Women with Endometriosis—Participation in the Pathogenesis of the Disease

Endometriosis is a disorder characterized by the presence of endometrial tissue outside the uterine cavity, primarily into the peritoneal cavity. It is known as a complex, chronic inflammatory disease and it is strongly associated with immune dysregulation. Various soluble mediators of the immune and inflammatory responses, including chemokines, play an important role in these processes. The aim of the study was to understand the role of the chemokines MCP-1, MCP-2, MCP-3, MCP-4, MIP-1 α, MIP-1β, eotaxin 2, eotaxin 3, ENA-78, and fractalkine in the development of endometriosis through their assessment in the peritoneal fluid of women with endometriosis. The study group included 58 women with endometriosis who were diagnosed during laparoscopy and then confirmed by histopathology. In 15 women from the reference group, laparoscopic examination demonstrated a normal status of the pelvic organs without any evidence of endometriosis nor inflammation in the peritoneal cavity. The peritoneal fluid of women with endometriosis and of women from the reference group were examined. To determine the concentration of the studied chemokines, enzyme immunoassays for Luminex® platforms were used. In the peritoneal fluid of women with endometriosis, a statistically significant increase in the concentration of MIP-1β, eotaxin 2, eotaxin 3, ENA-78, and fractalkine and a decrease in the concentration of MCP-1, MCP-2, MCP-3, MCP-4, and MIP-1α were observed compared to the reference group. The concentration of these cytokines depended on the severity of the disease. Changes in the concentration of the studied chemokines in the peritoneal fluid of women with endometriosis suggest their participation in the pathogenesis of the disease. The differences in chemokines concentration observed in different stages of endometriosis may be associated with the presence of inflammation in the peritoneal cavity at each step of disease development.

The role of endometrial stem cells in the pathogenesis of endometriosis and their application to its early diagnosis†

Pelvic pain, infertility, and a high postoperative recurrence rate are associated with endometriosis and adversely affect the physical and mental health of patients. Moreover, these factors place a heavy burden on families and society. The identification of endometrial stem cells (EnSCs) in the eutopic endometrium, menstrual blood, and ectopic lesions of women with endometriosis not only provides new research objects in the context of endometriosis but also promotes and improves our understanding of its pathogenesis. Furthermore, based on previous studies, we reasonably suppose that dysfunctions of eutopic EnSCs play a critical role in the onset of endometriosis and directly cause abnormalities in the endometrium; subsequently, retrograde menstruation facilitates the delivery of abnormal endometrial tissues to the ovaries and pelvic cavity, where they ectopically implant, grow, and form ectopic lesions. Additionally, as a chronically progressive disease, there is a delay (3-11 years) from the first onset of symptoms to the diagnosis of endometriosis. Therefore, the development of a method for early diagnosis with high sensitivity and specificity is essential for endometriosis patients and has the potential to enable early treatment, prevent endometriosis progression, and relieve pain in patients. Thus, focusing on EnSCs will contribute to clarifying the potential pathogenesis of endometriosis and provide support for the application of EnSCs as therapeutic and early diagnostic targets in endometriosis treatment.

SUMMARY SENTENCE

Focusing on endometrial stem cells (EnSCs) will contribute to clarifying the potential pathogenesis of endometriosis and provide support for the application of EnSCs as therapeutic and early diagnostic targets in endometriosis treatment.

Niclosamide suppresses macrophage-induced inflammation in endometriosis†

Endometriosis is a common gynecological disease, which causes chronic pelvic pain and infertility in women of reproductive age. Due to limited efficacy of current treatment options, a critical need exists to develop new and effective treatments for endometriosis. Niclosamide is an efficacious and FDA-approved drug for the treatment of helminthosis in humans that has been used for decades. We have reported that niclosamide reduces growth and progression of endometriosis-like lesions via targeting STAT3 and NFĸB signaling in a mouse model of endometriosis. To examine the effects of niclosamide on macrophage-induced inflammation in endometriosis, a total of 29 stage III-IV endometrioma samples were used to isolate human endometriotic stromal cells (hESCs). M1 or M2 macrophages were isolated and differentiated from fresh human peripheral blood samples. Then, hESCs were cultured in conditioned media (CM) from macrophages with/without niclosamide. Niclosamide dose dependently reduced cell viability and the activity of STAT3 and NFκB signaling in hESCs. While macrophage CM stimulated cell viability in hESCs, niclosamide inhibited this stimulation. Macrophage CM stimulated the secretion of proinflammatory cytokines and chemokines from hESCs. Most of these secreted factors were inhibited by niclosamide. These results indicate that niclosamide is able to reduce macrophage-induced cell viability and cytokine/chemokine secretion in hESCs by inhibiting inflammatory mechanisms via STAT3 and/or NFκB signaling.

Estrogen- and Progesterone (P4)-Mediated Epigenetic Modifications of Endometrial Stromal Cells (EnSCs) and/or Mesenchymal Stem/Stromal Cells (MSCs) in the Etiopathogenesis of Endometriosis

Endometriosis is a common chronic inflammatory condition in which endometrial tissue appears outside the uterine cavity. Because ectopic endometriosis cells express both estrogen and progesterone (P4) receptors, they grow and undergo cyclic proliferation and breakdown similar to the endometrium. This debilitating gynecological disease affects up to 15% of reproductive aged women. Despite many years of research, the etiopathogenesis of endometrial lesions remains unclear. Retrograde transport of the viable menstrual endometrial cells with retained ability for attachment within the pelvic cavity, proliferation, differentiation and subsequent invasion into the surrounding tissue constitutes the rationale for widely accepted implantation theory. Accordingly, the most abundant cells in the endometrium are endometrial stromal cells (EnSCs). These cells constitute a particular population with clonogenic activity that resembles properties of mesenchymal stem/stromal cells (MSCs). Thus, a significant role of stem cell-based dysfunction in formation of the initial endometrial lesions is suspected. There is increasing evidence that the role of epigenetic mechanisms and processes in endometriosis have been underestimated. The importance of excess estrogen exposure and P4 resistance in epigenetic homeostasis failure in the endometrial/endometriotic tissue are crucial. Epigenetic alterations regarding transcription factors of estrogen and P4 signaling pathways in MSCs are robust in endometriotic tissue. Thus, perspectives for the future may include MSCs and EnSCs as the targets of epigenetic therapies in the prevention and treatment of endometriosis. Here, we reviewed the current known changes in the epigenetic background of EnSCs and MSCs due to estrogen/P4 imbalances in the context of etiopathogenesis of endometriosis. Graphical Abstract.

Interleukin-9 produced by helper T cells stimulates interleukin-8 expression in endometriosis

PROBLEM

Inflammation and immune responses play crucial roles in the development of endometriosis. Although interleukin-9 (IL-9) has a pro-inflammatory function in chronic inflammatory diseases, its function in endometriosis remains unknown. Here, we aimed to investigate the significance of IL-9 and IL-9-producing lymphocytes in endometriosis.

METHOD OF STUDY

Specimens were obtained from patients with and without endometriosis. Peritoneal fluid (PF), peripheral blood (PB), and ovarian endometrioma (OE) tissues were analyzed for the proportion of CD4⁺ IL-9⁺ lymphocytes and IL-9 concentration using flow cytometry and enzyme-linked immunosorbent assay. OE, endometrium with endometriosis (EE), and normal endometrium (NE) were analyzed for IL-9 receptor (IL-9R) expression using immunohistochemical staining. IL-9-dependent changes in Interleukin-8 (IL-8) expression in endometrial stromal cells from OE (OESCs) were evaluated using real-time PCR.

RESULTS

The proportion of CD4⁺ IL-9⁺ lymphocytes was higher in the PF, but not the PB, of patients with endometriosis than individuals without endometriosis (p < .05). However, IL-9 levels in the PF did not differ between those with and without endometriosis. We detected CD4+ IL-9+ lymphocytes in OE tissues and IL-9R in OE tissues and OESCs. In OESC culture, IL-9 significantly elevated IL-8 expression in a dose-dependent manner (p < .05), which was nullified by the addition of the anti-IL-9 receptor antibody. Furthermore, IL-9 additively stimulated IL-8 expression in the presence of TNF-α (p < .05).

CONCLUSION

Our findings show that IL-9 produced by helper T cells induces IL-8 expression, suggesting that IL-9 plays an important role in the development of endometriosis by stimulating IL-8 expression.

The Effect of Novel Medical Nonhormonal Treatments on the Angiogenesis of Endometriotic Lesions

Importance

Irrespective of the precise mechanisms leading to endometriosis, angiogenesis is essential for the establishment and long-term proliferation of the disease. As current surgical and medical management options for women with endometriosis have substantial drawbacks and limitations, novel agents are needed and molecules targeting the angiogenic cascade could serve as potential candidates.

Objective

Our aim was to review current data about the role of angiogenesis in the pathophysiology of endometriosis and summarize the novel antiangiogenic agents that could be potentially used in clinical management of patients with endometriosis.

Evidence Acquisition

Original research and review articles were retrieved through a computerized literature search.

Results

Loss of balance between angiogenic activators and suppressors triggers the nonphysiological angiogenesis observed in endometriotic lesions. Several proangiogenic mediators have been identified and most of them have demonstrated increased concentrations in the peritoneal fluid and/or serum of women with endometriosis. Among the antiangiogenic molecules, anti-vascular endothelial growth factor agents, dopamine agonists, romidepsin, and statins have shown the most promising results so far.

Conclusions and Relevance

Given the limitations of current treatments of endometriosis, there is a need for novel, more efficient agents. Antiangiogenic molecules could be used potentially in clinical management of women with endometriosis; however, their safety and efficiency should be carefully assessed prior to that. Further large prospective trials in humans are needed before any treatment is introduced into daily clinical practice.

Functional changes of immune cells: signal of immune tolerance of the ectopic lesions in endometriosis?

RESEARCH QUESTION

What is the potential role of immune cells and their inflammatory cytokines in the pathogenesis, development and establishment of endometriosis?

DESIGN

Peritoneal fluid from 59 women (43 with endometriosis and 16 controls) who had undergone laparoscopic surgery was analysed. Changes in the population of innate and adaptive immune cells, cytokines, chemokines and growth factor expression were measured by flow cytometry, Luminex Technology and enzyme-linked immunosorbent assay.

RESULTS

No differences were found in the frequencies of the innate and adaptive immune cells between women with and without endometriosis. In the peritoneal fluid of women with endometriosis, IL-1β, IL-1RN, IL-2, IL-4, IL-8, IL-10, IL-12 (p70), IL-17α, FGF2, G-CSF, MCP-1, MIP-1α and TNF-α were significantly increased compared with controls. A correlation between IL-2, MCP-1, MIP-1α, TNF-α and the severity of endometriosis was observed. The concentration of neopterin, a possible biomarker for this disease, was increased in women with endometriosis compared with controls.

CONCLUSIONS

The functional activity of immune cells seemed to be reduced despite their numbers remaining unchanged. The data indicate that a shift of T_H cytokine profile occurs, which increases the T_H1-T_H2 ratio. This is driven by the increased levels of the cytokines (TNF-α and IL-2) in women with severe endometriosis.

The Inflammatory Role of Pro-Resolving Mediators in Endometriosis: An Integrative Review

The pathogenesis of endometriosis is still controversial, although it is known that the inflammatory immune response plays a critical role in this process. The resolution of inflammation is an active process where the activation of endogenous factors allows the host tissue to maintain homeostasis. The mechanisms by which pro-resolving mediators (PRM) act in endometriosis are still little explored. Thus, this integrative review aims to synthesize the available content regarding the role of PRM in endometriosis. Experimental and in vitro studies with Lipoxin A4 demonstrate a potential inhibitory effect on endometrial lesions' progression, attenuating pro-inflammatory and angiogenic signals, inhibiting proliferative and invasive action suppressing intracellular signaling induced by cytokines and estradiol, mainly through the FPR2/ALX. Investigations with Resolvin D1 demonstrated the inhibition of endometrial lesions and decreased pro-inflammatory factors. Annexin A1 is expressed in the endometrium and is specifically present in women with endometriosis, although the available studies are still inconsistent. Thus, we believe there is a gap in knowledge regarding the PRM pathways in patients with endometriosis. It is important to note that these substances' therapeutic potential is evident since the immune and abnormal inflammatory responses play an essential role in endometriosis development and progression.

Hypothetical roadmap towards endometriosis: prenatal endocrine-disrupting chemical pollutant exposure, anogenital distance, gut-genital microbiota and subclinical infections

BACKGROUND

Endometriosis is a gynaecological hormone-dependent disorder that is defined by histological lesions generated by the growth of endometrial-like tissue out of the uterus cavity, most commonly engrafted within the peritoneal cavity, although these lesions can also be located in distant organs. Endometriosis affects ~10% of women of reproductive age, frequently producing severe and, sometimes, incapacitating symptoms, including chronic pelvic pain, dysmenorrhea and dyspareunia, among others. Furthermore, endometriosis causes infertility in ~30% of affected women. Despite intense research on the mechanisms involved in the initial development and later progression of endometriosis, many questions remain unanswered and its aetiology remains unknown. Recent studies have demonstrated the critical role played by the relationship between the microbiome and mucosal immunology in preventing sexually transmitted diseases (HIV), infertility and several gynaecologic diseases.

OBJECTIVE AND RATIONALE

In this review, we sought to respond to the main research question related to the aetiology of endometriosis. We provide a model pointing out several risk factors that could explain the development of endometriosis. The hypothesis arises from bringing together current findings from large distinct areas, linking high prenatal exposure to environmental endocrine-disrupting chemicals with a short anogenital distance, female genital tract contamination with the faecal microbiota and the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis.

SEARCH METHODS

We performed a search of the scientific literature published until 2019 in the PubMed database. The search strategy included the following keywords in various combinations: endometriosis, anogenital distance, chemical pollutants, endocrine-disrupting chemicals, prenatal exposure to endocrine-disrupting chemicals, the microbiome of the female reproductive tract, microbiota and genital tract, bacterial vaginosis, endometritis, oestrogens and microbiota and microbiota-immune system interactions.

OUTCOMES

On searching the corresponding bibliography, we found frequent associations between environmental endocrine-disrupting chemicals and endometriosis risk. Likewise, recent evidence and hypotheses have suggested the active role of genital subclinical microbial infections in the development and clinical progression of endometriosis. Hence, we can envisage a direct relationship between higher prenatal exposure to oestrogens or estrogenic endocrine-disrupting compounds (phthalates, bisphenols, organochlorine pesticides and others) and a shorter anogenital distance, which could favour frequent postnatal episodes of faecal microbiota contamination of the vulva and vagina, producing cervicovaginal microbiota dysbiosis. This relationship would disrupt local antimicrobial defences, subverting the homeostasis state and inducing a subclinical inflammatory response that could evolve into a sustained immune dysregulation, closing the vicious cycle responsible for the development of endometriosis.

WIDER IMPLICATIONS

Determining the aetiology of endometriosis is a challenging issue. Posing a new hypothesis on this subject provides the initial tool necessary to design future experimental, clinical and epidemiological research that could allow for a better understanding of the origin of this disease. Furthermore, advances in the understanding of its aetiology would allow the identification of new therapeutics and preventive actions.

Uterine Stem Cells and Benign Gynecological Disorders: Role in Pathobiology and Therapeutic Implications

Stem cells in the endometrium and myometrium possess an immense regenerative potential which is necessary to maintain the menstrual cycle and support pregnancy. These cells, as well as bone marrow stem cells, have also been implicated in the development of common benign gynecological disorders including leiomyomas, endometriosis and adenomyosis. Current evidence suggests the conversion of uterine stem cells to tumor initiating stem cells in leiomyomas, endometriosis stem cells, and adenomyosis stem cells, acquiring genetic and epigenetic alterations for the progression of each benign condition. In this comprehensive review, we aim to summarize the progress that has been made to characterize the involvement of stem cells in the pathogenesis of benign gynecologic conditions which, despite their enormous burden, are not yet fully understood. We focus on the stem cell characteristics and aberrations that contribute to the development of benign gynecological disorders and the possible clinical implications of what is known so far. Lastly, we discuss the role of uterine stem cells in the setting of regenerative medicine, particularly in the treatment of Asherman syndrome.Graphical abstract.

Mesothelial Cells Participate in Endometriosis Fibrogenesis Through Platelet-Induced Mesothelial-Mesenchymal Transition

CONTEXT

While fibrosis in endometriosis has recently loomed prominently, the sources of myofibroblasts, the principal effector cell in fibrotic diseases, remain largely obscure. Mesothelial cells (MCs) can be converted into myofibroblasts through mesothelial-mesenchymal transition (MMT) in many fibrotic diseases and adhesion.

OBJECTIVE

To evaluate whether MCs contribute to the progression and fibrogenesis in endometriosis through MMT.

SETTING, DESIGN, PATIENTS, INTERVENTION, AND MAIN OUTCOME MEASURES

Dual immunofluorescence staining and immunohistochemistry using antibodies against calretinin, Wilms' tumor-1 (WT-1), and α-smooth muscle actin (α-SMA) were performed on lesion samples from 30 patients each with ovarian endometrioma (OE) and deep endometriosis (DE), and 30 normal endometrial (NE) tissue samples. Human pleural and peritoneal MCs were co-cultured with activated platelets or control medium with and without neutralization of transforming growth factor β1 (TGF-β1) and/or platelet-derived growth factor receptor (PDGFR) and their morphology, proliferation, and expression levels of genes and proteins known to be involved in MMT were evaluated, along with their migratory and invasive propensity, contractility, and collagen production.

RESULTS

The number of calretinin/WT-1 and α-SMA dual-positive fibroblasts in OE/DE lesions was significantly higher than NE samples. The extent of lesional fibrosis correlated positively with the lesional α-SMA staining levels. Human MCs co-cultured with activated platelets acquire a morphology suggestive of MMT, concomitant with increased proliferation, loss of calretinin expression, and marked increase in expression of mesenchymal markers. These changes coincided with functional differentiation as reflected by increased migratory and invasive capacity, contractility, and collagen production. Neutralization of TGF-β1 and PDGFR signaling abolished platelet-induced MMT in MCs.

CONCLUSIONS

MCs contribute to lesional progression and fibrosis through platelet-induced MMT.

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

OBJECTIVE

To investigate the role(s) of hyaluronan synthase 2 (HAS2) and hyaluronan in disease progression of endometriosis and epidermal growth factor (EGF)-induced motility changes of endometriotic cells.

DESIGN

A case-control experimental study and in vitro primary cell culture study.

SETTING

University hospital-affiliated research centers.

PATIENTS

A total of 21 women with stage I/II endometriosis, 33 women with stage III/IV endometriosis with endometrioma, and 32 women without endometriosis were included in our study.

INTERVENTIONS

Serum, eutopic endometrial tissues, and/or ectopic endometriotic tissues were collected. Primary eutopic endometrial stromal cells (EuESCs) and ectopic ovarian endometriotic stromal cells (OvESCs) were isolated and cultured from women with ovarian endometrioma, and then treated with or without EGF.

MAIN OUTCOME MEASURES

The concentrations of EGF and hyaluronan in serum were analyzed by enzyme-linked immunosorbent assay. The expressions and localizations of EGF receptor (EGFR), phosphorylated-(p)EGFR, HAS2, and hyaluronan receptor CD44 in tissues were examined by immunohistochemistry. The mRNA and protein levels of HAS2 in EuESCs and OvESCs were examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot, respectively, and the concentrations of hyaluronan in conditioned medium were examined by enzyme-linked immunosorbent assay (ELISA). Cell motility was evaluated by transwell migration/invasion assays.

RESULTS

Serum EGF and hyaluronan concentrations were higher in women with stage III/IV endometriosis than in women with stage I/II or without endometriosis. EGFR, pEGFR, HAS2, and CD44 were immunolocalized in eutopic endometrium and ectopic endometriotic lesions, and the expressions of pEGFR and HAS2 were elevated in ectopic endometriotic lesions compared to eutopic endometrium. Treatment with EGF upregulated HAS2 and hyaluronan expression as well as cell migration and invasion in both EuESCs and OvESCs, and pharmaceutical blocking of EGFR abolished these effects. In addition, knockdown of HAS2 by small interfering RNA attenuated both basal and EGF-induced hyaluronan expression and cell motility changes. Notably, ERK1/2 and AKT signaling pathways were shown to be downstream of EGF in regulating HAS2 and hyaluronan expression as well as cell migration and invasion.

CONCLUSION

EGF increased the expression of endometriosis-associated hyaluronan and its synthase HAS2, both of which mediated EGF-induced stromal cell migration and invasion in women with endometriosis.

Cytokine and growth factor profile in endometriosis: a multiplex analysis of peritoneal fluid to assess diagnostic utility

We aimed to assay cytokines and growth factors in peritoneal fluid samples from women with and without endometriosis to understand the inflammatory milieu, and assess their potential diagnostic utility. This cross-sectional study conducted at a tertiary care hospital included 54 women, aged 20-45 years, with regular menstrual history and undergoing diagnostic/therapeutic laparoscopy for infertility and/or pain. Peritoneal fluid samples were collected after insertion of trocar & laparoscope but prior to other surgical intervention. A multiplex immunoassay of 27 cytokines and growth factors was performed. The concentration of FGF2 and CSF3 were significantly lower in women with endometriosis than without endometriosis (p = .043 and .003, respectively). The levels of CCL2 and IL1RN were significantly higher in moderate-severe than in minimal-mild endometriosis (p = .038 and .043, respectively). Phase-specific comparison revealed that in proliferative phase, the levels of CSF2 and CSF3 were lower in women with endometriosis than without the disease (p = .047 and .013, respectively). The ROC curve analysis provided a cutoff value 0.78 and 0.76 for FGF2 and CSF3, respectively. Cytokines and growth factors such as FGF2, CSF3, CSF2, CCL2 and IL1RN seem to contribute to the pathogenesis of endometriosis and may have a potential utility for the diagnosis of endometriosis.

Letrozole and the Traditional Chinese Medicine, Shaofu Zhuyu Decoction, Reduce Endometriotic Disease Progression in Rats: A Potential Role for Gut Microbiota

We previously showed that the Chinese herbal medicine, Shaofu Zhuyu decoction (SFZYD), shrank the size of endometriotic lesions in rats with endometriosis. We therefore conducted the present study to investigate the effects of letrozole and SFZYD on gut microbiota in endometriotic rats. Rats were divided into four groups: a blank group, model group, letrozole group, and SFZY group. Ectopic lesion size and COX-2 expression in the endometrium and endometriotic lesions were compared, and the community of gut microbiota was detected using 16S rRNA gene sequencing. Both letrozole and SFZYD reduced the size of ectopic lesions as well as lowered the expression of COX-2, thus reducing the inflammatory response. Compared with the blank group, the α-diversity of gut microbiota in endometriotic rats decreased, the Firmicutes/Bacteroidetes ratio increased, and the abundance of Ruminococcaceae was reduced. The α-diversity of gut microbiota in the letrozole group was similar to that in the model group, but the Firmicutes/Bacteroidetes ratio was diminished. The α-diversity in the SFZY group was similar to that in the blank group, the Firmicutes/Bacteroidetes ratio was attenuated, and the abundance of Ruminococcaceae was elevated compared with the model group. These results indicated that the therapeutic mechanisms of both letrozole and SFZYD were related to the restoration of gut microbiota.

<p>In vivo Screening of Natural Products Against Angiogenesis and Mechanisms of Anti-Angiogenic Activity of Deoxysappanone B 7,4ʹ-Dimethyl Ether</p>

Introduction

The aim of this study was to screen the leading compounds of natural origin with anti-angiogenic potential and to investigate their anti-angiogenic mechanism preliminarily.

Materials and Methods

An initial screening of 240 compounds from the Natural Products Collection of MicroSource was performed using the transgenic zebrafish strain Tg [fli1a: enhanced green fluorescent protein (EGFP)]^y1. The zebrafish embryos at 24 h post-fertilization were exposed to the natural compounds for an additional 24 h; then, morphological changes in the intersegmental vessels (ISVs) were observed and quantified under a fluorescence microscope. The expression profiles of angiogenesis-related genes in the zebrafish embryos were detected using quantitative real-time PCR.

Results

Five compounds were identified with potential anti-angiogenic activity on the zebrafish embryogenesis. Among them, deoxysappanone B 7.4ʹ-dimethyl ether (Deox B 7,4) showed anti-angiogenic activity on the formation of ISVs in a dose-dependent manner. The inhibition of ISV formation reached up to 99.64% at 5 μM Deox B 7,4. The expression of delta-like ligand 4 (dll4), hes-related family basic helix-loop-helix transcription factor with YRPW motif 2, ephrin B2, fibroblast growth factor receptor (fgfr) 3, cyclooxygenase-2, protein tyrosine phosphatase, receptor type B (ptp-rb), phosphoinositide-3-kinase regulatory subunit 2, slit guidance ligand (slit) 2, slit3, roundabout guidance receptor (robo) 1, robo2, and robo4 were down-regulated, while vascular endothelial growth factor receptor-2, fgfr 1, and matrix metallopeptidase 9 were up-regulated in the zebrafish embryos treated with Deox B 7,4.

Conclusion

Deox B 7,4 has a therapeutic potential for the treatment of angiogenesis-dependent diseases and may exert anti-angiogenic activities by suppressing the slit2/robo1/2, slit3/robo4, cox2/ptp-rb/pik3r2, and dll4/hey2/efnb2a signaling pathways as well as activation of vegfr-2/fgfr1/mmp9.

Does the Use of the "Proseek® Multiplex Oncology I Panel" on Peritoneal Fluid Allow a Better Insight in the Pathophysiology of Endometriosis, and in Particular Deep-Infiltrating Endometriosis?

Endometriosis appears to share certain cancer-related processes, such as cell attachment, invasion, proliferation and neovascularization, some of which can also be found in other healthy tissues. In order to better understand the altered milieu of the peritoneal cavity, while acknowledging the reported similarities between endometriosis and neoplastic processes, we applied a multiplex oncology panel to search for specific biomarker signatures in the peritoneal fluid of women with endometriosis, women with deep-infiltrating endometriosis (DIE), as well as controls. In total, 84 patients were included in our study, 53 women with endometriosis and 31 controls. Ninety-two proteins were measured in prospectively collected peritoneal fluid (PF) samples, using the "Proseek® Multiplex Oncology I Panel". We first compared patients with endometriosis versus controls, and in a second step, DIE versus endometriosis patients without DIE. Out of the 92 analyzed proteins, few showed significant differences between the groups. In patients with endometriosis, ICOS ligand, Endothelial growth factor, E-selectin, Receptor tyrosine-protein kinase erbB-2, Interleukin-6 receptor alpha, Vascular endothelial growth factor receptor 2, Fms-related tyrosine kinase 3 ligand, C-X-C motif chemokine 10, Epididymal secretory protein E4 and Folate receptor-alpha were decreased, while Interleukin-6 and Interleukin-8 were increased compared to controls. Looking at patients with DIE, we found Chemokine ligand 19, Stem cell factor, Vascular endothelial growth factor D, Interleukin-6 receptor alpha and Melanoma inhibitory activity to be increased compared to endometriosis patients without DIE. We have shown a distinct regulation of the immune response, angiogenesis, cell proliferation, cell adhesion and inhibition of apoptosis in PF of patients with endometriosis compared to controls. The specific protein pattern in the PF of DIE patients provides new evidence that DIE represents a unique entity of extrauterine endometriosis with enhanced angiogenetic and pro-proliferative features.

The effect of new cross linked hyaluronan gel on quality of life of patients after deep infiltrating endometriosis surgery: a randomized controlled pilot study

In this prospective randomised placebo-controlled study, we aimed to evaluate the effect of New Cross linked Hyaluronan Gel (NCH gel) on the quality of life of patients who underwent laparoscopic surgery due to Deep Infiltrating Endometriosis (DIE). The intervention group received 40 mL of NCH gel, and the control group had a 40 mL sterile saline solution instilled into the peritoneal cavity following standard laparoscopic procedures. The patients were called in the third and sixth postoperative months and requested to fill the Visual Analogue Scale (VAS), Endometriosis Health Profile (EHP-5), and Short Form for Mental and Physical Health (SF-12) questionnaires. There was a significant reduction in dysmenorrhoea, dyschezia, dyspareunia VAS scores at 3rd, and 6th-month visits in NCH gel group. The postoperative 6th-month EHP-5 scores were significantly lower (1.16 ± 1.51, p-value: .02) in NCH gel group. Besides, NCH gel group had higher SF-12 mental and SF-12 physical scores. Clinical Trials registration number: NCT04023383IMPACT STATEMENTWhat is already known on this subject? Application of solid or liquid physical barriers is believed to be a promising strategy to reduce adhesions after laparoscopic endometriosis surgery. However, comparable data regarding the effects of adhesion barriers are still lacking.What the results of this study add? We revealed that there was a significantly higher decrease in VAS and EHP-5 scores and an increase in SF-12 physical-mental ratings after surgery in NCH gel group.What are the implications of these findings for clinical practice and/or further research? Using NHC gel in addition to standard surgical procedure improves postoperative VAS scores, and provides better quality of life scores.

Malignant Transformation and Associated Biomarkers of Ovarian Endometriosis: A Narrative Review

This review focuses on pathogenesis of endometriosis, its possible biomarkers and role in endometriosis-associated ovarian cancer. We analyzed various databases to obtain new insights, theories, and biomarkers associated with endometriosis. There are several theories of endometriosis development and biomarker changes including atypical forms. A number of studies have attempted to establish specific, reliable biomarkers to help diagnose endometriosis and endometriosis-associated diseases on the basis of different pathogenetic pathways. Nevertheless, despite intensive research extending even to the molecular level, the origin, natural history, malignant transformation, and laboratory management of endometriosis and related diseases are not yet clearly defined. Therefore, early laboratory diagnoses of endometriosis, its atypical form, and endometriosis-associated ovarian tumors are important problems that require further study in the context of advanced therapeutic strategies to provide maximal health benefits to patients.

Peritoneal Fluid Cytokines Reveal New Insights of Endometriosis Subphenotypes

Endometriosis is a common inflammatory gynecological disorder which causes pelvic scarring, pain, and infertility, characterized by the implantation of endometrial-like lesions outside the uterus. The peritoneum, ovaries, and deep soft tissues are the commonly involved sites, and endometriotic lesions can be classified into three subphenotypes: superficial peritoneal endometriosis (PE), ovarian endometrioma (OE), and deep infiltrating endometriosis (DIE). In 132 women diagnosed laparoscopically with and without endometriosis (n = 73, 59 respectively), and stratified into PE, OE, and DIE, peritoneal fluids (PF) were characterized for 48 cytokines by using multiplex immunoassays. Partial-least-squares-regression analysis revealed distinct subphenotype cytokine signatures—a six-cytokine signature distinguishing PE from OE, a seven-cytokine signature distinguishing OE from DIE, and a six-cytokine-signature distinguishing PE from DIE—each associated with different patterns of biological processes, signaling events, and immunology. These signatures describe endometriosis better than disease stages (p < 0.0001). Pathway analysis revealed the association of ERK1 and 2, AKT, MAPK, and STAT4 linked to angiogenesis, cell proliferation, migration, and inflammation in the subphenotypes. These data shed new insights on the pathophysiology of endometriosis subphenotypes, with the potential to exploit the cytokine signatures to stratify endometriosis patients for targeted therapies and biomarker discovery.

Platelets induce endothelial-mesenchymal transition and subsequent fibrogenesis in endometriosis

RESEARCH QUESTION

Do endometriotic lesions undergo endothelial-mesenchymal transition (EndoMT)?

DESIGN

Lesion samples from 30 patients with ovarian endometriomas and deep endometriosis, and control endometrial tissue samples from 30 women without endometriosis, were analysed. In-vitro experimentation using the human umbilical vein endothelial cell (HUVEC) line were conducted. Immunofluorescence staining and immunohistochemistry analysis using antibodies against endothelial cell and mesenchymal cell markers were conducted. The HUVEC cells were co-cultured with activated platelets or control medium with and without neutralization of TGF-β1 PDGFR, or both. Their morphology, proliferation and expression levels of genes and proteins known to be involved in EndoMT were evaluated, along with their migratory and invasive propensity, contractility and collagen production capability.

RESULTS

The proportion of CD31 and FSP-1 dual-positive cells in FSP-1+ fibroblasts was 74.7% (±5.4%) in ovarian endometrioma lesions, significantly higher than that in deep endometriosis lesions (26.8% ± 26.0%; P = 5.7 × 10^-5), and was zero in normal endometrium. The extent of lesional fibrosis correlated positively with staining levels of the lesional mesenchymal markers FSP-1 and α-SMA (r = 0.91; P < 2.2 × 10^-16, r = 0.81; P = 5.8 × 10^-15, respectively). Human endothelial cells co-cultured with activated platelets acquire a morphology suggestive of EndoMT, concomitant with increased proliferation, loss of CD31 but marked increase in expression of mesenchymal markers. Morphological and gene and protein expression changes are accompanied by functional differentiation reflected by increased migratory and invasive capacity, contractility and collagen production. Neutralization of TGF-β1 and PDGFR signalling abolished platelet-induced EndoMT in human endothelial cells.

CONCLUSIONS

Multiple sources of myofibroblasts exist in endometriotic lesions, and implicates platelets, EndoMT, or both, as potential therapeutic targets for treating endometriosis.

Peritoneal fluid biomarkers in patients with endometriosis: a cross-sectional study

OBJECTIVES

Elevated concentrations of numerous molecules have been reported in the peritoneal cavity of women with endometriosis. Until now, no factor proved sufficiently specific to endometriosis. We aimed to investigate several biomarkers in endometriosis and report their association with the menstrual cycle in a large sample size study.

METHODS

Patients of reproductive age undergoing laparoscopic procedures for benign pathology in the Department of Obstetrics and Gynaecology, University of Bern between 2007 and 2018 were included. Exclusion criteria were the use of hormonal treatment in the three months prior to surgery, patients suffering from other inflammatory diseases, pregnancy, malignancy and surgery performed in an emergency. The concentrations of 13 different biomarkers in the peritoneal fluid (PF) were compared between patients with and without endometriosis both in the proliferative and the secretory cycle phase.

RESULTS

Out of 1,256 patients in the database, 521 met the inclusion and exclusion criteria. Glycodelin (PP14) and Midkine concentrations were significantly higher in patients with endometriosis compared to controls irrespective of the cycle phase in which the PF was collected. Interleukin-8 (IL-8), regulated on activation normal T cell expressed and secreted (RANTES) and osteoprotegerin (OPG) concentrations were higher in patients with endometriosis only in the proliferative cycle phase. Monocyte chemoattractant protein 1, CCL2 (MCP-1) and Defensin concentrations were higher in patients with endometriosis only in the secretory cycle phase.

CONCLUSIONS

Certain pathophysiological processes may take place only in the one cycle phase leading to a temporary increase of specific PF biomarkers. Correlation with clinical outcomes is mandatory to establish their potential as prognostic or therapeutic tools in endometriosis.

Elevated Levels of Monocyte Chemotactic Protein-1 in the Follicular Fluid Reveals Different Populations among Women with Severe Endometriosis

To determine if a modification of the cytokine profile occurs in the follicular fluid (FF) of women with endometriosis undergoing in vitro fertilization (IVF), we performed a prospective observational study from January 2018 to February 2019. In total, 87 women undergoing IVF were included: 43 for severe endometriosis-related infertility and 40 controls with other causes of infertility. The cytokine profile of the FF was determined by multiplex fluorescent-bead-based technology allowing the measurement of 59 cytokines. Monocyte Chemoattractant Protein 1 (MCP-1) was the only variable retained in the multivariate analysis. We identified two subgroups of patients in the endometriosis group: MCP-1-low group (n = 23), which had FF MCP-1 levels comparable to the control group, and MCP-1-high (n = 20), which had significantly higher FF levels. Only patients in the MCP-1-high group had a significantly altered cytokine profile in the FF, and had a significantly higher serum estradiol level (p = 0.002) and a significantly lower number of oocytes recovered (p = 0.01) compared to the MCP-1-low and the control group. Our study has shown an alteration of the oocyte microenvironment in women with endometriosis associated with high follicular fluid levels of MCP-1, allowing the identification of a subgroup of endometriosis patients with a potentially worse prognosis.

The Effect of Rutin and Extracts of Uncaria guianensis (Aubl.) J. F. Gmeland on Primary Endometriotic Cells: A 2D and 3D Study

There is increasing interest in the potential of natural compounds to treat diseases, such as endometriosis, a gynecological disorder that affects 10–15% of women of reproductive age, and it is related to severe pelvic pain and infertility. We have evaluated the in vitro effects of rutin and the aqueous bark, roots, and leaf extracts (ABE, ARE, and ALE, respectively) and isolated components of Uncaria guianensis on stromal cells from eutopic endometrium and lesions of patients with endometriosis. Two- and three-dimensional cultures were used to assess the cell death and production of reactive oxygen species (ROS), cytokines and growth factors of cells following exposure to these natural products. The applied treatments did not reduce cellular viability, but ROS production did increase. In addition, significant increases in the levels of interleukin (IL)-15, IL-17A, IL-4, IL-6, tumor necrosis factor-α, and vascular endothelium growth factor were observed when 2D-cells from endometrium of patients with endometriosis were treated with ABE, while exposure to ALE induced significant increases in epidermal growth factor in lesion cells.

Adipose-derived stem cell-conditioned medium protects fibroblasts at different senescent degrees from UVB irradiation damages

Adipose-derived stem cells (ADSCs) and their derivatives have aroused intense interest in fields of dermatological and aesthetic medicine. As a major component detected in ADSCs secretome, platelet-derived growth factor AA (PDGF-AA) has been reported mediating extracellular matrix deposition and remodeling, thus might contribute to its anti-aging effect. On the basis of establishing an experimental model that simulate actual skin aging by exposing HDFs to both intrinsic and extrinsic aging factors, we pretreated human dermal fibroblasts (HDFs) with ADSC-conditioned medium (ADSC-CM) before being irradiated, aiming at exploring preventive effects of ADSCs secretome against aging damages. 48 h after irradiation, we detected cellular proliferation; β-galactosidase stain; mRNA expressions of MMP-1, MMP-9, and TIMP-1; and protein expressions of collagen I, collagen III, and elastin. Moreover, we detected related protein expression of PI3K/Akt signal pathway, which can be activated by PDGF-AA and was newly found to promote extracellular matrix protein synthesis. Concentration of PDGF-AA in the prepared ADSC-CM decreased over time and maintained excellent bioactivity at low temperature until the 11th week. ADSC-CM pretreatment can slightly or significantly improve cellular proliferative activity and reduce cellular senescence in irradiated HDFs. Besides, ADSC-CM pretreatment increased collagen I, collagen III, elastin, and TIMP-1 expressions but decreased MMP-1 and MMP-9 expressions both in irradiated and nonirradiated HDFs. ADSC-CM pretreatment significantly increased pAkt protein expression, and ECM protein expression greatly decreased in case of LY294002 application. The results were similar in three generations of HDFs, yet varied with different degrees. Generally, ADSC-CM we prepared demonstrates a certain degree of positive role in preventing HDFs from intrinsic and extrinsic aging damages and that PDGF-AA may contribute to making it become effective with some other components in ADSC-CM.

poFUT1 promotes uterine angiogenesis and vascular remodeling via enhancing the O-fucosylation on uPA

Uterine angiogenesis and vascular remodeling play critical roles in determing the normal menstrual cycle and successful pregnancy. Poor uterine angiogenesis usually results in pregnancy failure. Protein O-fucosyltransferase 1 (poFUT1) is the key enzyme responsible for O-fucosylated glycan biosynthesis on glycoproteins. However, the dynamic expression and regulation of poFUT1 on the uterine angiogenesis and vascular remodeling remain unknown. Here, we showed that the enlargement of the vascular lumen in the secretory phase was greater than that in the proliferative phase of the uterine endometrium during menstrual cycle; whereas there was a narrower vessel lumen and fewer blood vessels in the decidua from miscarriage patients than in that from healthy pregnancy women. Additionally, the expression of poFUT1 was increased in the uterine endometrium during the secretory phase compared with that in the proliferation phase, and its expression was decreased in the uterus of miscarriage patients compared with that of the healthy pregnancy women. Using hESCs and a mouse model, we demonstrated that poFUT1 increased the O-fucosylation on uPA, and activated of the RhoA signaling pathway, thus facilitating uterine angiogenesis and vascular remodeling. We also provide evidence that poFUT1 promotes hESCs angiogenesis by the decreased stemness of hESCs. These findings reveal a new insight into the uterine angiogenesis and vascular remodeling. The study suggests that poFUT1 could be seen as a novel potential diagnostic and therapeutic target for miscarriage.

Ameliorative effects of luteolin against endometriosis progression in vitro and in vivo

Endometriosis is a common gynecological disease in reproductive-aged women. Generally, accumulation of backflow and debris of endometrial tissue develops into a lesion outside of the endometrium, inducing severe pelvic pain and infertility in some patients. Hormone therapy and surgery are the main treatments available, but various therapeutic phytochemicals are being reviewed in animal studies or clinical trials for endometriosis patients nowadays. However, the therapeutic effects of luteolin in human endometriosis have not been studied well. Here, we demonstrate that luteolin exerts antiproliferative and apoptotic effects in human VK2/E6E7 and End1/E6E7 and in an animal endometriosis model. Luteolin inhibits cell proliferation through cell cycle arrest and induces apoptosis through DNA fragmentation in VK2/E6E7 and End1/E6E7 cells. Cytosolic calcium levels, ROS production and lipid peroxidation also increased dose-dependently (0, 5, 10 and 20 μM) in the treatment with luteolin. In VK2/E6E7 and End1/E6E7 cells, luteolin decreased ERK1/2, JNK and PI3K/AKT signal proteins while activating P38. In addition, intraperitoneal injection of luteolin in the endometriosis mouse model reduced lesion size compared to vehicle-injected mice. Ccne1, Cdk2 and Cdk4 were significantly down-regulated in the autoimplanted endometriosis lesions of mice intraperitoneally injected with luteolin. Knockdown of CCNE1 mRNA in VK2/E6E7 and End1/E6E7 cells decreased cell viability through inhibition of G0/G1 phase progression and increased apoptosis. Together, our results imply that luteolin suppresses endometriosis development by regulation of the PI3K/AKT and MAPK signal proteins as well as the expression of CCNE1 in vitro and in vivo.

Pathogenesis of endometriosis: the genetic/epigenetic theory

OBJECTIVE

To study the pathophysiology of endometriosis.

DESIGN

Overview of observations on endometriosis.

SETTING

Not applicable.

PATIENT(S)

None.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The hypothesis is compatible with all observations.

RESULT(S)

Endometriosis, endometrium-like tissue outside the uterus, has a variable macroscopic appearance and a poorly understood natural history. It is a hereditary and heterogeneous disease with many biochemical changes in the lesions, which are clonal in origin. It is associated with pain, infertility, adenomyosis, and changes in the junctional zone, placentation, immunology, plasma, peritoneal fluid, and chronic inflammation of the peritoneal cavity. The Sampson hypothesis of implanted endometrial cells following retrograde menstruation, angiogenic spread, lymphogenic spread, or the metaplasia theory cannot explain all observations if metaplasia is defined as cells with reversible changes and an abnormal behavior/morphology due to the abnormal environment. We propose a polygenetic/polyepigenetic mechanism. The set of genetic and epigenetic incidents transmitted at birth could explain the hereditary aspects, the predisposition, and the endometriosis-associated changes in the endometrium, immunology, and placentation. To develop typical, cystic ovarian or deep endometriosis lesions, a variable series of additional transmissible genetic and epigenetic incidents are required to occur in a cell which may vary from endometrial to stem cells. Subtle lesions are viewed as endometrium in a different environment until additional incidents occur. Typical cystic ovarian or deep endometriosis lesions are heterogeneous and represent three different diseases.

CONCLUSION(S)

The genetic epigenetic theory is compatible with all observations on endometriosis. Implications for treatment and prevention are discussed.

Cancer driver mutations in endometriosis: Variations on the major theme of fibrogenesis

BACKGROUND

One recent study reports cancer driver mutations in deep endometriosis, but its biological/clinical significance remains unclear. Since the natural history of endometriosis is essentially gradual progression toward fibrosis, it is thus hypothesized that the six driver genes reported to be mutated in endometriosis (the RP set) may play important roles in fibrogenesis but not necessarily malignant transformation.

METHODS

Extensive PubMed search to see whether RP and another set of driver genes not yet reported (NR) to be mutated in endometriosis have any roles in fibrogenesis. All studies reporting on the role of fibrogenesis of the genes in both RP and NR sets were retrieved and evaluated in this review.

RESULTS

All six RP genes were involved in various aspects of fibrogenesis as compared with only three NR genes. These nine genes can be anchored in networks linking with their upstream and downstream genes that are known to be aberrantly expressed in endometriosis, piecing together seemingly unrelated findings.

CONCLUSIONS

Given that somatic driver mutations can and do occur frequently in physiologically normal tissues, it is argued that these mutations in endometriosis are not necessarily synonymous with malignancy or premalignancy, but the result of enormous pressure for fibrogenesis.

Identification of mundoserone by zebrafish in vivo screening as a natural product with anti-angiogenic activity

The present study aimed to screen natural products with anti-angiogenic potential from the Natural Products Collection of MicroSource. The anti-angiogenic activity of 240 natural products was assessed using the zebrafish line Tg(fli1a: EGFP)^y1. At 24 h post-fertilization, the embryos were treated with the library compounds for 24 h and, the morphology of the intersegmental vessels (ISVs) was then assessed using a fluorescence microscope, followed by counting of ISVs and calculation of the inhibition ratio. The expression of angiogenesis-associated genes was determined by quantitative polymerase chain reaction. The results indicated that mundoserone inhibited ISV formation in zebrafish embryos in a dose-dependent manner, with a significant anti-angiogenic activity observed at a concentration of 10 µM, leading to an ISV inhibition ratio of 73.6±1.3%. Mundoserone significantly reduced the expression of slit guidance ligand 3 (SLIT3), roundabout guidance receptor 1 (ROBO1) and -2, fibroblast growth factor receptor (FGFR)2 and -3, as well as protein tyrosine phosphatase, receptor type B (PTP-RB), but increased the expression of NOTCH1A. Accordingly, mundoserone may be an effective angiogenic inhibitor, which acts via downregulation of SLIT/ROBO1 and FGFR/PTP-RB, and upregulation of NOTCH1A signaling.

Chronic Niche Inflammation in Endometriosis-Associated Infertility: Current Understanding and Future Therapeutic Strategies

Endometriosis is an estrogen-dependent inflammatory disease that affects up to 10% of women of reproductive age and accounts for up to 50% of female infertility cases. It has been highly associated with poorer outcomes of assisted reproductive technology (ART), including decreased oocyte retrieval, lower implantation, and pregnancy rates. A better understanding of the pathogenesis of endometriosis-associated infertility is crucial for improving infertility treatment outcomes. Current theories regarding how endometriosis reduces fertility include anatomical distortion, ovulatory dysfunction, and niche inflammation-associated peritoneal or implantation defects. This review will survey the latest evidence on the role of inflammatory niche in the peritoneal cavity, ovaries, and uterus of endometriosis patients. Nonhormone treatment strategies that target these inflammation processes are also included. Furthermore, mesenchymal stem cell-based therapies are highlighted for potential endometriosis treatment because of their immunomodulatory effects and tropism toward inflamed lesion foci. Potential applications of stem cell therapy in treatment of endometriosis-associated infertility in particular for safety and efficacy are discussed.

Effects of etonogestrel implant on quality of life, sexual function, and pelvic pain in women suffering from endometriosis: results from a multicenter, prospective, observational study

PURPOSE

Progestins are successfully employed as treatment for endometriosis. Our study evaluates the effects of the etonogestrel (ENG) implant on pelvic pain, quality of life, and sexual function in women requiring long-term reversible contraception and presenting ovarian cysts of probable endometriotic origin.

METHODS

We enrolled 25 women asking for contraception with the ENG implant and presenting a cyst with the ultrasound features of an endometrioma and pain symptoms. Patients were interviewed on pain symptoms (dysmenorrhea, dyspareunia, dyschezia, and dysuria) using a VAS score (0-10), on quality of life (QoL) using the Short Form-36 questionnaire, and on sexual activity using the Female Sexual Function Index (FSFI) questionnaire before inserting the implant (T0) and after 6 (T1) and 12 months (T2).

RESULTS

We found a significant decrease in dysmenorrhea and dyspareunia VAS scores comparing baseline scores to 6 and 12 months. After 12 months, the bodily pain, general health, vitality, social functioning, and mental health domains of the QoL score were significantly improved. The total FSFI score results increased in comparison with baseline both at 6 and 12 months. In particular, we highlighted a significant improvement in desire, satisfaction, and pain domains already at 6 months; the arousal domain improved only after 12 months. Finally, mean diameters of endometrioma-like cysts were not changed after 12 months of treatment.

CONCLUSIONS

Etonogestrel implants seem to be able to reduce pelvic pain, improve sexual function, and quality of life in patients with ovarian cysts suspected of endometriotic origin.

Annexin A1, FPR2/ALX, and inflammatory cytokine expression in peritoneal endometriosis

To characterize Annexin A1 (ANXA1), FPR2/ALX and cytokines expression in peritoneal endometriosis and to clarify their role in its etiology, a cross-sectional study was performed with forty women in reproductive age (22 patients with endometriosis and 18 control women) that had undergone laparoscopic surgery. Peritoneal biopsy and fluid aspirations from endometriosis and control samples were analyzed for the expression of ANXA1, FPR2/ALX and cytokines. ANXA1 and FPR2 / ALX levels were measured by Western blotting and interleukin 1ß (IL-1β), interleukin 4 (IL-4), interleukin 6 (IL-6), and interleukin 10 (IL-10) levels were quantified by enzyme-linked immunosorbent assay (ELISA). The present study identified the presence in human peritoneal tissue of ANXA1 and FPR2 / ALX both in healthy condition and in women with peritoneal endometriosis, however, was lower in endometriosis samples than in control samples. By quantifying the IL-6 and IL-1β cytokines in the peritoneal fluid by ELISA, this study identified a higher IL-6 concentration in endometriosis group, but no significative difference in IL-1ß levels. The IL-4 and IL-10 levels could not be detected. These results indicate that the reduction of the inflammatory resolution mediators could be responsible for the inflammatory process perpetuation, maintenance and worsening of endometriosis.

Micro-RNA profile and proteins in peritoneal fluid from women with endometriosis: their relationship with sterility

OBJECTIVE

To define the microRNA (miRNA) profile and its relationship with cytokines content in peritoneal fluid (PF) from endometriosis patients.

DESIGN

Case-control study.

SETTING

University hospital, research institute.

PATIENT(S)

One hundred twenty-six women with endometriosis (EPF) and 45 control women (CPF).

MAIN OUTCOMES MEASURE(S)

MiRNA arrays were prepared from six EPF and six CPF. Quantitative reverse transcription-polymerase chain reaction validation of nine selected miRNAs (miR-29c-3p, -106b-3p, -130a-3p, -150-5p, -185-5p, -195-5p, -451a, -486-5p, and -1343-5p) was performed. Vascular endothelial growth factor-A (VEGF-A), thrombospondin-1 (TSP-1), urokinase plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-3 (MMP3), tissue inhibitor of metalloproteinases type 1 (TIMP-1), interleukin (IL)-6, IL-8, IL-17A, macrophage inflammatory protein 1β (MIP1beta), platelet-derived growth factor α-polypeptide A, and regulated on activation, normal T cell expressed and secreted (RANTES) were quantified by ELISA and MILLIPLEX.

RESULT(S)

MiRNA arrays showed 126 miRNAs differentially expressed (fold change ±1.2) (78 down-regulated, 48 up-regulated) in EPF. Validation showed higher levels of miR-106b-3p, -451a, -486-5p, IL-6, IL-8, uPA, and TIMP-1 in EPF. In menstrual phase, EPF presented up-regulation of miR-106b-3p, -130a-3p, -150-5p, -185-5p, -451a, -486-5p, VEGF-A, IL-8, MIF 1β, uPA, and PAI-1 compared with other phases; however, CPF did not. MiRNA-486-5p was up-regulated in sterile EPF compared with sterile controls, and VEGF-A, IL-8, and TIMP-1 were increased in sterile and fertile EPF compared with fertile CPF.

CONCLUSION(S)

MiRNAs seem to be involved in the peritoneal alterations in endometriosis, suggesting new mechanisms by which ectopic lesions could implant in endometriosis patients; and to serve as biomarkers for fertility outcome prediction.

Treg and NK cells related cytokines are associated with deep rectosigmoid endometriosis and clinical symptoms related to the disease

The aim of this study was to evaluate Treg and NK cells related cytokines in deep infiltrating endometriosis lesions and its relationship with clinical symptoms of the disease. mRNA expression of Transforming Growth Factor Beta (TGFB), Interleukin (IL)10, Interferon Gamma (IFNG), IL7, and IL15 was analyzed by Real-Time PCR in eutopic endometrium and rectosigmoid lesions from 11 women with deep infiltrating endometriosis and in eutopic endometrium from 11 healthy women. IL10, IFNG, and IL7 expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from women with endometriosis. IL10 and TGFB expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from healthy women. In addition, TGFB and IL15 levels correlated positively with deep dyspareunia and cyclic dyschezia, respectively, while IL7 levels correlated negatively with dysmenorrhea. Deep infiltrating rectosigmoid endometriosis displays alterations in Treg and NK cells related cytokine, and TGFB, IL7 and IL15 expression is related with dyspareunia, dysmenorrhea and cyclic dyschezia, respectively, in patients with the disease.

Basic mechanisms of vascularization in endometriosis and their clinical implications

BACKGROUND

Vascularization is a major hallmark in the pathogenesis of endometriosis. An increasing number of studies suggests that multiple mechanisms contribute to the vascularization of endometriotic lesions, including angiogenesis, vasculogenesis and inosculation.

OBJECTIVE AND RATIONALE

In this review, we provide an overview of the basic mechanisms of vascularization in endometriosis and give special emphasis on their future clinical implications in the diagnosis and therapy of the disease.

SEARCH METHODS

Literature searches were performed in PubMed for English articles with the key words 'endometriosis', 'endometriotic lesions', 'angiogenesis', 'vascularization', 'vasculogenesis', 'endothelial progenitor cells' and 'inosculation'. The searches included both animal and human studies. No restriction was set for the publication date.

OUTCOMES

The engraftment of endometriotic lesions is typically associated with angiogenesis, i.e. the formation of new blood vessels from pre-existing ones. This angiogenic process underlies the complex regulation by angiogenic growth factors and hormones, which activate intracellular pathways and associated signaling molecules. In addition, circulating endothelial progenitor cells (EPCs) are mobilized from the bone marrow and recruited into endometriotic lesions, where they are incorporated into the endothelium of newly developing microvessels, referred to as vasculogenesis. Finally, preformed microvessels in shed endometrial fragments inosculate with the surrounding host microvasculature, resulting in a rapid blood supply to the ectopic tissue. These vascularization modes offer different possibilities for the establishment of novel diagnostic and therapeutic approaches. Angiogenic growth factors and EPCs may serve as biomarkers for the diagnosis and classification of endometriosis. Blood vessel formation and mature microvessels in endometriotic lesions may be targeted by means of anti-angiogenic compounds and vascular-disrupting agents.

WIDER IMPLICATIONS

The establishment of vascularization-based approaches in the management of endometriosis still represents a major challenge. For diagnostic purposes, reliable angiogenic and vasculogenic biomarker panels exhibiting a high sensitivity and specificity must be identified. For therapeutic purposes, novel compounds selectively targeting the vascularization of endometriotic lesions without inducing severe side effects are required. Recent progress in the field of endometriosis research indicates that these goals may be achieved in the near future.

Should we consider integrated approach for endometriosis-associated infertility as gold standard management? Rationale and results from a large cohort analysis

PURPOSE

To evaluate reproductive and maternal-fetal outcomes after integrated approach for endometriosis-associated infertility (EAI).

METHODS

We retrospectively analyzed reproductive and maternal-fetal outcomes of 277 women affected by EAI, subdividing patients in two groups: in the first one (surgery group), we included all women who underwent laparoscopic surgery for EAI; in the second one (integrated group), we included women who failed to conceive spontaneously after surgery within 6-12 months and underwent in vitro fertilization and embryo transfer (IVF). We evaluated delivery rate (DR), maternal and neonatal outcomes of the first pregnancies, and, finally, the type (spontaneous or IVF) of subsequent pregnancies.

RESULTS

We did not find significant difference regarding DR between surgery and integrated groups. We found significantly lower birth weight (p < 0.001) and gestational age at delivery (p < 0.001) in integrated group respect to surgery group; conversely, we found higher rate of preterm birth (p < 0.001), small for gestational age (p = 0.003), and admission to the neonatal intensive care unit (p < 0.001) respect to surgery group. Finally, 92 women became pregnant for the second time: 8% were spontaneous and 20% were IVF pregnancies.

CONCLUSIONS

We suggest the integrated approach as gold standard treatment for carefully selected patients (young, good ovarian reserve, partner with normal semen parameters) affected by EAI. As consequence, IVF should be reserved as the secondary treatment for women who fail to conceive spontaneously after surgery within 6-12 months, since it is able to increase DR significantly.