Cyclooxygenase-2 regulates survival, migration, and invasion of human endometriotic cells through multiple mechanisms

Role of the gut microbiota in the pathogenesis of endometriosis: a review

Endometriosis is classically defined as a chronic inflammatory heterogeneous disorder occurring in any part of the body, characterized by estrogen-driven periodic bleeding, proliferation, and fibrosis of ectopic endometrial glands and stroma outside the uterus. Endometriosis can take overwhelmingly serious damage to the structure and function of multi-organ, even impair whole-body systems, resulting in severe dysmenorrhea, chronic pelvic pain, infertility, fatigue and depression in 5-10% women of reproductive age. Precisely because of a huge deficiency of cognition about underlying etiology and complex pathogenesis of the debilitating disease, early diagnosis and treatment modalities with relatively minor side effects become bottlenecks in endometriosis. Thus, endometriosis warrants deeper exploration and expanded investigation in pathogenesis. The gut microbiota plays a significant role in chronic diseases in humans by acting as an important participant and regulator in the metabolism and immunity of the body. Increasingly, studies have shown that the gut microbiota is closely related to inflammation, estrogen metabolism, and immunity resulting in the development and progression of endometriosis. In this review, we discuss the diverse mechanisms of endometriosis closely related to the gut microbiota in order to provide new approaches for deeper exploration and expanded investigation for endometriosis on prevention, early diagnosis and treatment.

Proteomic detection of COX-2 pathway-related factors in patients with adenomyosis

Background

Investigating the relationship between cyclooxygenase-2 (COX-2) pathway-related factors and clinical features in patients with adenomyosis by proteomics could provide potential therapeutic targets.

Methods

This study recruited 40 patients undergoing surgical hysterectomy and pathological diagnosis of adenomyosis, collected ectopic endometrial specimens, and recorded clinical data. The expression levels of COX-2 in ectopic uterus lesions were detected using the immunohistochemical (IHC) SP method. The 40 samples were then divided into a COX-2 low or high expression group. Five samples with the most typical expression levels were selected from each of the two groups and the differential proteins between the two groups were identified using label-free quantitative proteomics. WW domain-binding protein 2 (WBP2), interferon induced transmembrane protein 3 (IFITM3), and secreted frizzled-related protein 4 (SFRP4) were selected for further verification, and their relationships with COX-2 and clinical characteristics were analyzed.

Results

There were statistically significant differences in the expression of WBP2, IFITM3, and SFRP4 between the COX-2 low and high expression groups (P < 0.01). The expressions of COX-2, IFITM3, and SFRP4 were significantly correlated with dysmenorrhea between the two groups (P < 0.05), but not with uterine size or menstrual volume (P > 0.05). However, there was no significant correlation between the expression of WBP2 and dysmenorrhea, uterine size, and menstruation volume in both the high expression and low expression groups (P > 0.05).

Conclusions

COX-2, IFITM3, SFRP4, and WBP2 may be involved in the pathogenesis of adenomyosis. COX-2, IFITM3, and SFRP4 may serve as potential molecular biomarkers or therapeutic targets in dysmenorrhea in patients with early adenomyosis.

Research Trends of Acupuncture Therapy on Chronic Pelvic Pain Syndrome from 2000 to 2022: A Bibliometric Analysis

Background

Acupuncture is considered an important means of analgesic, which has been widely used in chronic pelvic pain syndrome (CPPS) management and treatment in recent years, published a large number of related documents. However, the relevant literature in this field has not been summarized and quantitatively analyzed. Therefore, this study aims to analyze the hotspots and predicting future research trends of acupuncture on pelvic pain syndrome.

Methods

Search for the relevant publications of the web of science database from 2000 to 2022 about the treatment of acupuncture on chronic pelvic pain syndrome. The Citespace software and VosViewer software are used to analyze the visualization of the countries, institutions, authors, keywords and references and references in the literature.

Results

A total of 173 publications were included. The annual number of essays gradually showed an overall growth trend over time. Medicine magazine is the most published journal in this field. J UROLOGY and Acupunct Med are the most cited journals and the most influential magazines; The most active and influential country is China, and the most produced institutions are Beijing University of Chinese Medicine; The most produced authors are Liu Zhishun. The most cited and most influential authors are Nickel JC and Armour M; keywords and cited reference analysis show that the quality of life, mechanism research, alternative medicine and electro-acupuncture will be the scientific hotspot of acupuncture treatment for chronic pelvic pain syndrome.

Conclusion

This study shows that acupuncture on CPPS is increasingly valued and recognized. The future research hotspots will focus on the effects and mechanisms. In the future, more high-quality animal basic research will be required to explore the exact mechanism of acupuncture on CPPS. In addition, different parameters of acupuncture such as electric-acupuncture, stimulating frequency, duration and strength are also the focus of future research. More clinical trials are required to verify its safety and effectiveness.

Targeting EP2 Receptor for Drug Discovery: Strengths, Weaknesses, Opportunities, and Threats (SWOT) Analysis

Cyclooxygenase-1 and -2 (COX1 and COX2) derived endogenous ligand prostaglandin-E2 (PGE2) triggers several physiological and pathological conditions. It mediates signaling through four G-protein coupled receptors, EP1, EP2, EP3, and EP4. Among these, EP2 is expressed throughout the body including the brain and uterus. The functional role of EP2 has been extensively studied using EP2 gene knockout mice, cellular models, and selective small molecule agonists and antagonists for this receptor. The efficacy data from in vitro and in vivo animal models indicate that EP2 receptor is a major proinflammatory mediator with deleterious functions in a variety of diseases suggesting a path forward for EP2 inhibitors as the next generation of selective anti-inflammatory and antiproliferative agents. Interestingly in certain diseases, EP2 action is beneficial; therefore, EP2 agonists seem to be clinically useful. Here, we highlight the strengths, weaknesses, opportunities, and potential threats (SWOT analysis) for targeting EP2 receptor for therapeutic development for a variety of unmet clinical needs.

The Tpl2-MEK pathway plays a critical role in spheroid-cultured endometriotic stromal cells

PROBLEM

Endometriosis is a proliferative disease characterized by cytokine-induced inflammation. The objective of this study was to assess cell growth and PGE₂ production induced by TNF-α in endometriotic stromal cells (ESCs) in spheroid cell culture and to identify the signaling pathway involved with a view to finding new therapeutic targets for endometriosis.

METHOD OF STUDY

Tissue samples were collected from patients with and without endometriosis. ESCs were isolated from ovarian endometrioma (OE). Gene expression was evaluated by real-time PCR and DNA microarray analysis, the proliferative effect on ESCs by WST-8 assay, and PGE₂ production by ELISA. Protein phosphorylation was detected using western blotting.

RESULTS

COX-2, aromatase and VEGFA mRNA expression and PGE₂ production were significantly elevated in spheroid cell cultures compared to monolayer cell cultures. TNF-α receptor (TNFR) 1 and TNFR2 mRNA was also significantly increased. TNF-α promoted the proliferation and PGE₂ production of ESCs in spheroid cell cultures significantly more than in monolayer cell cultures. TNF-α increased the expression of several genes related to the pathophysiology of endometriosis in spheroid ESCs. DNA microarray analysis revealed that the Tpl2 gene, which codes for a MAPK upstream of MEK, was upregulated in OE and endometrium with endometriosis compared to normal endometrium. TNF-α increased the phosphorylation and expression of Tpl2 and MEK, and Tpl2 and MEK inhibitors inhibited TNF-α-induced proliferation and PGE₂ production in spheroid ESCs.

CONCLUSION

The Tpl2-MEK signaling pathway may play a critical role in the cell growth and PGE₂ production induced by TNF-α in spheroid ESCs.

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.

Melatonin-primed MSCs alleviate intrauterine adhesions by affecting MSC-expressed galectin-3 on macrophage polarization

Intrauterine adhesion (IUA) is characterized by the presence of fibrosis on the uterine cavity. It is mainly caused by infection or trauma to the endometrium, and it imposes a great challenge to female reproductive health. Mesenchymal stem cells (MSCs) have been used to regenerate the human endometrium in patients with IUA, but stem cell therapy is not curative in some patients. Melatonin (MT) was reported as a potential modulator of MSCs. However, it remains unclear whether MSCs pretreated with MT exert an improved therapeutic effect on IUA. In this study, an IUA model was established using our invented electric scratching tool. Our results illustrated that MT-pretreated MSCs significantly attenuated the development of IUA. Moreover, MT-pretreated MSCs highly expressed galectin-3 (Gal-3), which enhanced MSC proliferation and migration and influenced macrophage polarization. Of note, IUA mice exhibited colonic injury, and MT-pretreated MSCs alleviated this injury by normalizing colonic microbial communities and recruiting macrophages. Furthermore, inhibition of sympathetic nerves had no effect on IUA progression but delayed colonic injury, and Gal-3 combined with norepinephrine better promoted M2-like macrophage polarization and inhibited M1-like macrophage polarization. Together, these data indicated that MT-primed MSCs can ameliorate injury of both the uterus and colon in an IUA model through high Gal-3 expression to influence sympathetic nerves and in turn affect the polarization and recruitment of macrophages.

Evaluating the effect of conditioned medium from endometrial stem cells on endometriosis-derived endometrial stem cells

Endometriosis is a common, benign gynecological disease which is determined as an overspreading of endometrial tissue in exterior region of the uterine cavity. Evidence suggests that retrograde menstrual blood which contains mesenchymal stem cells with differential gene expression compared to healthy women may play a role in endometriosis creation. We aimed to identify whether the conditioned medium (CM) from menstrual blood-derived mesenchymal stem cells (MenSCs) of healthy women can affect the expression level of inflammatory and stemness genes of MenSCs from endometriosis women. Endometriosis-derived MenSCs (E-MenSCs) were treated with CM derived from healthy women’s MenSCs (non-endometriosis derived MenSCs [NE-MenSCs]). Some CD markers were analyzed by flow cytometer before and after treatment compared with NE-MenSCs, and the expression level of inflammatory and stemness genes was evaluated by real-time PCR. E-MenSCs show different morphology in vitro culture in comparison with NE-MenSCs, which were changed in the presence of CM, into a morphology more similar to normal cells and showed significant decrease expression of CD10 after CM treatment. In our results, the interleukin-1, cyclooxygenase-2, and hypoxia-inducible factor 1α as inflamaturay genes and octamer-binding transcription factor 4, NANOG, and sex determining region Y-box 2 as stemness genes showed significantly different expression level in E-MenSCs after treating with CM. Our study indicates that the expression level of some inflammatory- and stemness-related genes which have differential expression in E-MenSCs compared with NE-MenSCs, could be changed to normal status by using CM derived from NE-MenSCs.

A Comparative Study of Gene Expression in Menstrual Blood-Derived Stromal Cells between Endometriosis and Healthy Women

Background. Research into the pathogenesis of endometriosis would substantially promote its effective treatment and early diagnosis. Currently, accumulating evidence has shed light on the importance of endometrial stem cells within the menstrual blood which are involved in the establishment and progression of endometriotic lesions in a retrograde manner. Objectives. We aimed to identify the differences in some genes’ expression between menstrual blood-derived mesenchymal stem cells (MenSCs) isolated from endometriosis patients (E-MenSCs) and MenSCs from healthy women (NE-MenSCs). Methods. Menstrual blood samples (2-3 mL) from healthy and endometriosis women in the age range of 22–35 years were collected. Isolated MenSCs by the Ficoll-Paque density-gradient centrifugation method were characterized by flow cytometry. MenSCs were evaluated for key related endometriosis genes by real-time-PCR. Results. E-MenSCs were morphologically different from NE-MenSCs and showed, respectively, higher and lower expression of CD10 and CD9. Furthermore, E-MenSCs had higher expression of Cyclin D1 (a cell cycle-related gene) and MMP-2 and MMP-9 (migration- and invasion-related genes) genes compared with NE-MenSCs. Despite higher cell proliferation in E-MenSCs, the BAX/BCL-2 ratio was significantly lower in E-MenSCs compared to NE-MenSCs. Also, the level of inflammatory genes such as IL1β, IL6, IL8, and NF-κB and stemness genes including SOX2 and SALL4 was increased in E-MenSCs compared with NE-MenSCs. Further, VEGF, as a potent angiogenic factor, showed a significant increase in E-MenSCs rather than NE-MenSCs. However, NE-MenSCs showed increased ER-α and β-catenin when compared with E-MenSCs. Conclusion. Here, we showed that there are gene expression differences between E-MenSCs and NE-MenSCs. These findings propose that MenSCs could play key role in the pathogenesis of endometriosis and further support the menstrual blood retrograde theory of endometriosis formation. This could be of great importance in exploiting promising therapeutic targets and new biomarkers for endometriosis treatment and prognosis.

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.

Effects of dual inhibition of AKT and ERK1/2 pathways on endometrial pro-inflammatory, hormonal, and epigenetic microenvironment in endometriosis

Endometriosis is an estrogen-dependent and progesterone-resistant gynecological inflammatory disease of reproductive-age women. The prevalence of endometriosis is ~5-10% in reproductive-age women, increasing to 20-30% in women with subfertility. The current anti-estrogen therapies can be prescribed only for a short time because of the undesirable side effects on menstruation, pregnancy, bone health, and failure to prevent a recurrence. The causes of endometriosis-associated infertility are multifactorial and poorly understood. The objective of the present study was to determine the inhibitory effects of AKT and/or ERK1/2 pathways on the microenvironment of the endometrium in a xenograft mouse model of endometriosis of human origin. Results indicate that dual inhibition of AKT and ERK1/2 pathways, but not inhibition of either AKT or ERK1/2 pathway, suppresses the growth of the endometriotic lesions in vivo. Dual inhibition of AKT and ERK1/2 pathways suppresses the production of proinflammatory cytokines, decreases E₂ biosynthesis and signaling, and restores progesterone receptor-B signaling components in the epithelial and stromal cells of the endometrium in a cell-specific manner. These results together suggest that dual inhibition of AKT and ERK1/2 pathways suppresses the estrogen-dominant state and concomitantly increases the progesterone-responsive state of the endometrium. Therefore, dual inhibition of AKT and ERK1/2 pathways could emerge as long-term nonsteroidal therapy for endometriosis.

Qiu's Neiyi Recipe Regulates the Inflammatory Action of Adenomyosis in Mice via the MAPK Signaling Pathway

Background

The management of adenomyosis is challenging and limiting. Qiu's Neiyi recipe (Qiu) is a traditional Chinese medicine (TCM) prescription clinically used for endometriosis treatment in China, but the effect and mechanism of Qiu on adenomyosis are undefined.

Methods

An experimental adenomyosis model was induced in female neonatal ICR mice administrated with tamoxifen. The adenomyosis mice were divided into five groups: high-, middle-, and low-Qiu's group, danazol group, and model group. The mice just administrated with the solvent only (no tamoxifen or drugs) were served as the control group. After 28 days of administration, the body, uterine, spleen, and thymus weights of all mice were examined. Then, the myometrial infiltration and the expression of inflammatory factors were detected by histology examination, ELISA, and qRT-PCR in the uterus. In addition, the MAPK/ERK signaling pathway-related protein expression in adenomyosis mice was detected by immunohistochemical (IHC) staining, qRT-PCR, and western blotting.

Results

In experimental adenomyosis mice, Qiu treatment improved the symptoms of adenomyosis by reducing the myometrial infiltration and increasing the index of spleen and thymus. The elevated levels of IL-1β, IL-6, and TNF-α in serum and uterus tissues of adenomyosis model mice were also decreased after Qiu treatment. The improvement of Qiu on the adenomyosis was achieved by inhibiting the activated MAPK/ERK signaling pathway, including reducing the mRNA and protein expressions of p-ERK/ERK, p-JNK/JNK, and p-p38/p38 in the uterus tissues.

Conclusion

Qiu alleviated the inflammatory reaction and uterus histological changes in mice with adenomyosis, and the potential mechanism is through the inhibition of the MAPK/ERK signaling pathway. Qiu may be a promising treatment for adenomyosis.

Involvement of bradykinin and bradykinin B1 receptor in patients with endometriosis

Endometriosis (EM), a benign aseptic inflammatory disease, is associated with the presence of endometrial foci. Pain, one of its typical symptoms, has been reported as a constant stressor, but the etiology and pathogenesis of EM-associated pain are unclear. In the present study, eutopic and ectopic endometrium samples from women with EM (n=50) and normal endometrium samples from control subjects (n=20) were collected. Serum levels of prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and bradykinin (BK) were measured using commercial ELISA kits. The expression of the BKB1 receptor (BKB1R) protein was evaluated by immunohistochemical staining and western blot assay. The mRNA expression of BKB1R was measured by reverse transcription-quantitative PCR. The results revealed that there was a substantial increase in the protein and mRNA expression of BKB1R, as well as the release of PGE2, PGF2α and BK in the blood, in the EM group compared with that in the control group. Moreover, PGE2, PGF2α and BK levels were significantly correlated with each other, as well as with the pain intensity of EM. The increased expression levels of BKB1R protein and mRNA were positively correlated with the pain degree of EM. Thus, these data indicated that BK and BKB1R were involved in the pathological onset of EM-associated pain and that they may play an important role in EM-related pain by inducing PGE2 and PGF2α. The data indicate a potential new therapeutic target for EM-related pain.

EP2 Antagonists (2011-2021): A Decade's Journey from Discovery to Therapeutics

In the wake of health disasters associated with the chronic use of cyclooxygenase-2 (COX-2) inhibitor drugs, it has been widely proposed that modulation of downstream prostanoid synthases or receptors might provide more specificity than simply shutting down the entire COX cascade for anti-inflammatory benefits. The pathogenic actions of COX-2 have long been thought attributable to the prostaglandin E2 (PGE2) signaling through its Gαs-coupled EP2 receptor subtype; however, the truly selective EP2 antagonists did not emerge until 2011. These small molecules provide game-changing tools to better understand the EP2 receptor in inflammation-associated conditions. Their applications in preclinical models also reshape our knowledge of PGE2/EP2 signaling as a node of inflammation in health and disease. As we celebrate the 10-year anniversary of this breakthrough, the exploration of their potential as drug candidates for next-generation anti-inflammatory therapies has just begun. The first decade of EP2 antagonists passes, while their future looks brighter than ever.

PPARγ Agonists: Emergent Therapy in Endometriosis

Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.

An Overview on the Conservative Management of Endometriosis from a Naturopathic Perspective: Phytochemicals and Medicinal Plants

Background: Endometriosis is a chronic and debilitating disease, which affects millions of young women worldwide. Although medicine has incontestably evolved in the last years, there is no common ground regarding the early and accurate diagnosis of this condition, its pathogenic mechanisms, and curative treatment. Even though the spontaneous resolution of endometriosis is sometimes possible, recent reports suggested that it can be a progressive condition. It can associate chronic pelvic pain, vaginal bleeding, infertility, or malignant degenerescence. Conventional treatments could produce many side effects, and despite treatment, the symptoms may reappear. In recent years, experimental evidence suggested that plant-based medicine could exert beneficial effects on endometriosis and endometriosis-related symptoms. This study aims to highlight the pharmaceutical activity of phytochemicals and medicinal plants against endometriosis and to provide a source of information regarding the alternative treatment of this condition. Methods: For this review, we performed a research using PubMed, GoogleScholar, and CrossRef databases. We selected the articles published between January 2000 and July 2020, written in English. Results: We found 17 medicinal plants and 13 phytochemicals, which have demonstrated their beneficial effects against endometriosis. Several of their biological activities consist of antiangiogenic, anti-inflammatory effects, and oxidative-stress reduction. Conclusion: Medicinal herbs and their bioactive compounds exhibit antiangiogenic, antioxidant, sedative and pain-alleviating properties and the effects recorded until now encourage their use for the conservative management of endometriosis.

Chitosan nanoparticles loaded with aspirin and 5-fluororacil enable synergistic antitumour activity through the modulation of NF-κB/COX-2 signalling pathway

Based on the enhancement of synergistic antitumour activity to treat cancer and the correlation between inflammation and carcinogenesis, the authors designed chitosan nanoparticles for co-delivery of 5-fluororacil (5-Fu: an as anti-cancer drug) and aspirin (a non-steroidal anti-inflammatory drug) and induced synergistic antitumour activity through the modulation of the nuclear factor kappa B (NF-κB)/cyclooxygenase-2 (COX-2) signalling pathways. The results showed that aspirin at non-cytotoxic concentrations synergistically sensitised hepatocellular carcinoma cells to 5-Fu in vitro. It demonstrated that aspirin inhibited NF-κB activation and suppressed NF-κB regulated COX-2 expression and prostaglandin E2 (PGE2) synthesis. Furthermore, the proposed results clearly indicated that the combination of 5-Fu and aspirin by chitosan nanoparticles enhanced the intracellular concentration of drugs and exerted synergistic growth inhibition and apoptosis induction on hepatocellular carcinoma cells by suppressing NF-κB activation and inhibition of expression of COX-2.

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 Endometriotic Stromal Cell Line from Human Ovarian Endometrioma

Endometrial-like stromal cells, one of the main components of endometriotic lesions, are an important in vitro model for studying cellular and molecular mechanisms associated with lesion development in endometriosis. However, the short life span of primary endometriotic stromal cells (Ec-ESCs) limits their use. Human telomerase reverse transcriptase (hTERT) plasmids can be used to develop immortalized cell lines. Here we aimed to establish an endometriotic stromal cell line by hTERT immortalization. Primary Ec-ESCs were obtained from a human ovarian endometriotic cyst. The purity was assessed by morphology and the expression of vimentin, cytokeratin, and human interferon-inducible transmembrane protein 1 (hIFITM1). Cells were infected with hTERT lentiviral vector and selected with hygromycin. hTERT mRNA levels were confirmed by RT-qPCR. Immortalized Ec-ESCs (iEc-ESCs) were characterized by examining the expression of morphological markers and key genes of interest, TP53, estrogen receptor β (ERβ), progesterone receptor (PR), and steroidogenic factor-1 (SF-1). Karyotyping and in vitro decidualization studies were also performed. Ec-ESCs were positive for vimentin and hIFITM1 and negative for cytokeratin, indicating that they were representative of Ec-ESC. The fibroblast-like morphology, expression of TP53, ERβ, PR, and SF-1 did not change before and after hTERT immortalization. iEc-ESCs showed an impaired decidualization response like primary Ec-ESCs when compared to normal eutopic stromal cells. Karyotyping showed that 15/19 cells had normal female karyotype, while 4/19 cells had partial trisomy 11q. Collectively, we successfully established and characterized an immortalized endometriotic stromal cell line. It is potentially useful as an in vitro experimental model to investigate endometriosis biology.

Pain in Endometriosis

Endometriosis is a chronic and debilitating condition affecting ∼10% of women. Endometriosis is characterized by infertility and chronic pelvic pain, yet treatment options remain limited. In many respects this is related to an underlying lack of knowledge of the etiology and mechanisms contributing to endometriosis-induced pain. Whilst many studies focus on retrograde menstruation, and the formation and development of lesions in the pathogenesis of endometriosis, the mechanisms underlying the associated pain remain poorly described. Here we review the recent clinical and experimental evidence of the mechanisms contributing to chronic pain in endometriosis. This includes the roles of inflammation, neurogenic inflammation, neuroangiogenesis, peripheral sensitization and central sensitization. As endometriosis patients are also known to have co-morbidities such as irritable bowel syndrome and overactive bladder syndrome, we highlight how common nerve pathways innervating the colon, bladder and female reproductive tract can contribute to co-morbidity via cross-organ sensitization.

The Role of Eicosanoids in Gynecological Malignancies

Eicosanoids, bio-active lipid molecules, evoke a multitude of biological effects that directly affect cancer cells and indirectly affect tumor microenvironment. An emerging role has been shown for eicosanoids in the pathogenesis of gynecological malignancies which include cancers of the vulva, vagina, cervix, uterine, and ovary. Eicosanoid biosynthesis pathways start at the metabolism of phospholipids by phospholipase A2 then proceeding to one of three pathways: the cyclooxygenase (COX), lipoxygenase (LOX), or P450 epoxygenase pathways. The most studied eicosanoid pathways include COX and LOX; however, more evidence is appearing to support further study of the P450 epoxygenase pathway in gynecologic cancers. In this review, we present the current knowledge of the role of COX, LOX and P450 pathways in the pathogenesis of gynecologic malignancies. Vulvar and vaginal cancer, the rarest subtypes, there is association of COX-2 expression with poor disease specific survival in vulvar cancer and, in vaginal cancer, COX-2 expression has been found to play a role in mucosal inflammation leading to disease susceptibility and transmission. Cervical cancer is associated with COX-2 levels 7.4 times higher than in healthy tissues. Additionally, HPV elevates COX-2 levels through the EGFR pathway and HIV promotes elevated COX-2 levels in cervical tissue as well as increases PGE2 levels eliciting inflammation and progression of cancer. Evidence supports significant roles for both the LOX and COX pathways in uterine cancer. In endometrial cancer, there is increased expression of 5-LOX which is associated with adverse outcomes. Prostanoids in the COX pathway PGE2 and PGF2α have been shown to play a significant role in uterine cancer including alteration of proliferation, adhesion, migration, invasion, angiogenesis, and the inflammatory microenvironment. The most studied gynecological malignancy in regard to the potential role of eicosanoids in tumorigenesis is ovarian cancer in which all three pathways have shown to be associated or play a role in ovarian tumorigenesis directly on the tumor cell or through modulation of the tumor microenvironment. By identifying the gaps in knowledge, additional pathways and targets could be identified in order to obtain a better understanding of eicosanoid signaling in gynecological malignancies and identify potential new therapeutic approaches.

Common and specific gene signatures among three different endometriosis subtypes

Aims

To identify the common and specific molecular mechanisms of three well-defined subtypes of endometriosis (EMs): ovarian endometriosis (OE), peritoneal endometriosis (PE), and deep infiltrating endometriosis (DIE).

Methods

Four microarray datasets: GSE7305 and GSE7307 for OE, E-MTAB-694 for PE, and GSE25628 for DIE were downloaded from public databases and conducted to compare ectopic lesions (EC) with eutopic endometrium (EU) from EMs patients. Differentially expressed genes (DEGs) identified by limma package were divided into two parts: common DEGs among three subtypes and specific DEGs in each subtype, both of which were subsequently performed with the Kyoto Encyclopedia of Genes (KEGG) pathway enrichment analysis. The protein-protein interaction (PPI) network was constructed by common DEGs and five hub genes were screened out from the PPI network. Besides, these five hub genes together with selected interested pathway-related genes were further validated in an independent OE RNA-sequencing dataset GSE105764.

Results

A total of 54 EC samples from three EMs subtypes (OE, PE, DIE) and 58 EU samples were analyzed, from which we obtained 148 common DEGs among three subtypes, and 729 specific DEGs in OE, 777 specific DEGs in PE and 36 specific DEGs in DIE. The most enriched pathway of 148 shared DEGs was arachidonic acid (AA) metabolism, in which most genes were up-regulated in EC, indicating inflammation was the most common pathogenesis of three subtypes. Besides, five hub genes AURKB, RRM2, DTL, CCNB1, CCNB2 identified from the PPI network constructed by 148 shared DEGs were all associated with cell cycle and mitosis, and down-regulated in EC, suggesting a slow and controlled proliferation in ectopic lesions. The KEGG pathway analysis of specific DEGs in each subtype revealed that abnormal ovarian steroidogenesis was a prominent feature in OE; OE and DIE seems to be at more risk of malignant development since both of their specific DEGs were enriched in the pathways in cancer, though enriched genes were different, while PE tended to be more associated with dysregulated peritoneal immune and inflammatory microenvironment.

Conclusion

By integrated bioinformatic analysis, we explored common and specific molecular signatures among different subtypes of endometriosis: activated arachidonic acid (AA) metabolism-related inflammatory process and a slow and controlled proliferation in ectopic lesions were common features in OE, PE and DIE; OE and DIE seemed to be at more risk of malignant development while PE tended to be more associated with dysregulated peritoneal immune and inflammatory microenvironment, all of which could deepen our perception of endometriosis.

Biomarkers for the Noninvasive Diagnosis of Endometriosis: State of the Art and Future Perspectives

BACKGROUND

Early and accurate diagnosis of endometriosis is crucial for the management of this benign, yet debilitating pathology. Despite the advances of modern medicine, there is no common ground regarding the pathophysiology of this disease as it continues to affect the quality of life of millions of women of reproductive age. The lack of specific symptoms often determines a belated diagnosis. The gold standard remains invasive, surgery followed by a histopathological exam. A biomarker or a panel of biomarkers is easy to measure, usually noninvasive, and could benefit the clinician in both diagnosing and monitoring the treatment response. Several studies have advanced the idea of biomarkers for endometriosis, thereby circumventing unnecessary invasive techniques. Our paper aims at harmonizing the results of these studies in the search of promising perspectives on early diagnosis.

METHODS

We selected the papers from Google Academic, PubMed, and CrossRef and reviewed recent articles from the literature, aiming to evaluate the effectiveness of various putative serum and urinary biomarkers for endometriosis.

RESULTS

The majority of studies focused on a panel of biomarkers, rather than a single biomarker and were unable to identify a single biomolecule or a panel of biomarkers with sufficient specificity and sensitivity in endometriosis.

CONCLUSION

Noninvasive biomarkers, proteomics, genomics, and miRNA microarray may aid the diagnosis, but further research on larger datasets along with a better understanding of the pathophysiologic mechanisms are needed.

Cyclooxygenase-2 in Endometriosis

Endometriosis (EMS) is the most common gynecological disease in women of reproductive age, and it is associated with chronic pelvic pain, dyspareunia and infertility. As a consequence of genetic, immune and environmental factors, endometriotic lesions have high cyclooxygenase (COX)-2 and COX-2-derived prostaglandin E₂ (PGE₂) biosynthesis compared with the normal endometrium. The transcription of the PTGS2 gene for COX-2 is associated with multiple intracellular signals, which converge to cause the activation of mitogen-activated protein kinases (MAPKs). COX-2 expression can be regulated by several factors, such as estrogen, hypoxia, proinflammatory cytokines, environmental pollutants, metabolites and metabolic enzymes, and platelets. High concentrations of COX-2 lead to high cell proliferation, a low level of apoptosis, high invasion, angiogenesis, EMS-related pain and infertility. COX-2-derived PGE₂ performs a crucial function in EMS development by binding to EP2 and EP4 receptors. These basic findings have contributed to COX-2-targeted treatment in EMS, including COX-2 inhibitors, hormone drugs and glycyrrhizin. In this review, we summarize the most recent basic research in detail and provide a short summary of COX-2-targeted treatment.

Development and utilization of human decidualization reporter cell line uncovers new modulators of female fertility

Failure of embryo implantation accounts for a significant percentage of female infertility. Exquisitely coordinated molecular programs govern the interaction between the competent blastocyst and the receptive uterus. Decidualization, the rapid proliferation and differentiation of endometrial stromal cells into decidual cells, is required for implantation. Decidualization defects can cause poor placentation, intrauterine growth restriction, and early parturition leading to preterm birth. Decidualization has not yet been systematically studied at the genetic level due to the lack of a suitable high-throughput screening tool. Herein we describe the generation of an immortalized human endometrial stromal cell line that uses yellow fluorescent protein under the control of the prolactin promoter as a quantifiable visual readout of the decidualization response (hESC-PRLY cells). Using this cell line, we performed a genome-wide siRNA library screen, as well as a screen of 910 small molecules, to identify more than 4,000 previously unrecognized genetic and chemical modulators of decidualization. Ontology analysis revealed several groups of decidualization modulators, including many previously unappreciated transcription factors, sensory receptors, growth factors, and kinases. Expression studies of hits revealed that the majority of decidualization modulators are acutely sensitive to ovarian hormone exposure. Gradient treatment of exogenous factors was used to identify EC₅₀ values of small-molecule hits, as well as verify several growth factor hits identified by the siRNA screen. The high-throughput decidualization reporter cell line and the findings described herein will aid in the development of patient-specific treatments for decidualization-based recurrent pregnancy loss, subfertility, and infertility.

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

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

Correlation of LOX‑5 and COX‑2 expression with inflammatory pathology and clinical features of adenomyosis

Adenomyosis is a common benign disease of women of childbearing age. The typical clinical features are prolonged menstruation, menorrhagia and ingravescent dysmenorrhea. In the present study, the severity of dysmenorrhea was assessed using the visual analogue scale system as follows: 0, No pain; 1‑3, minimal pain; 4‑6, moderate pain; and 7‑10, severe pain. Menstrual blood loss was evaluated using the pictorial blood loss assessment chart (PBAC). Menorrhagia was defined as excessive menstrual blood loss >80 ml (PBAC >100) per period. Specimens of eutopic endometrium (EU) and ectopic endometrium (EC) were collected from 20 patients with adenomyosis to evaluate the association between lipoxygenase‑5 (LOX‑5) and cyclooxygenase 2 (COX‑2) and inflammatory pathology and clinical features of adenomyosis. For that purpose, the expression levels of LOX‑5, COX‑2, interleukin (IL)‑6 and IL‑8 in the EU and EC of patients with adenomyosis were determined, and clinical data including dysmenorrhea and menstruation were analyzed. Differences in expression levels of LOX‑5 and COX‑2 were detected, and the correlations between LOX‑5, COX‑2, IL‑6 and IL‑8 in different groups were analyzed. In addition, the correlations between LOX‑5, COX‑2 and clinical features of adenomyosis were investigated. The present study demonstrated that LOX‑5 and COX‑2 are overexpressed in EU and EC, and they have positive correlations with IL‑6 and IL‑8, suggesting that adenomyosis lesions are present in inflammatory pathological conditions. The expression levels of LOX‑5 and COX‑2 exhibited a correlation with dysmenorrhea and menstruation.

Exposure to environmental concentrations of hexachlorobenzene induces alterations associated with endometriosis progression in a rat model

Hexachlorobenzene (HCB) is a dioxin-like compound widely distributed and is a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is a disease characterized by growth of endometrial tissue in ectopic sites. Our aim was to investigate the impact of HCB on the endocrine, invasion and inflammatory parameters in a rat endometriosis model surgically induced. Female rats were exposed to HCB (1, 10 and 100 mg/kg b.w.) during 30 days. Results showed that HCB increases endometriotic like-lesions (L) volume in a dose-dependent manner. In L, HCB10 increases microvessel density (immunohistochemistry) and the vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and AhR levels (Western Blot), while HCB1 enhances aromatase expression (Western Blot). In addition, in eutopic endometrium (EU), HCB10/HCB100 augments microvessel density, VEGF and MMP-9 expression, while HCB1/HCB10 increases tumor necrosis factor-α (TNF-α) content in peritoneal fluid (ELISA). Interestingly, both L and EU from HCB-treated rats exhibited higher estrogen receptor α (ERα) (immunohistochemistry) and metalloproteases (MMP)-2 and -9 levels (Western Blot), as well as lower progesterone receptor (PR) expression (immunohistochemistry) than in control rats. Environmentally relevant concentrations of HCB could contribute to abnormal changes associated with endometriosis progression and development.

Effects of different progestins on prostaglandin biosynthesis in human endometrial explants

OBJECTIVE

To compare the effects of chlormadinone acetate (CMA), dienogest (DNG) and drospirenone (DRSP) on prostaglandin biosynthesis in a human endometrial explants model.

STUDY DESIGN

Human endometrial explants obtained by aspiration curettage and human endometrial YHES cells were stimulated with interleukin-1β (IL-1β) and exposed to CMA, DNG, DRSP or dexamethasone (DEX; YHES cells). Cellular messenger RNA (mRNA) levels of cyclooxygenase-2 (COX-2) were analyzed by reverse-transcription quantitative real-time polymerase chain reaction. Concentrations of prostaglandin F_2α (PGF_2α) in culture supernatants were measured by enzyme-linked immunosorbent assay.

RESULTS

CMA exerted after IL-1β stimulation a stronger down-regulation of COX-2 mRNA compared to DNG and DRSP in human explants (-55% vs. -40% and 46%, respectively). The effect of CMA on COX-2 mRNA was significantly stronger (p=.025) than that of DNG. Moreover, the effect of CMA was independent from cycle phase or presence of endometriosis. In order to evaluate the impact of the investigated progestins on effector molecules, PGF_2α release was determined in supernatants. Again, CMA reduced the PGF_2α release significantly by an average of -60% (p<.01). In contrast, no significant reduction was found for DNG and DRSP. In YHES cells, only DEX but not the progestins under study exerted a significant down-regulating effect (-79%, p<.01) on COX-2 mRNA after IL-1β stimulation.

CONCLUSION

Among the tested progestins, CMA displayed the most consistent suppression of prostaglandin biosynthesis in human endometrial explants.

IMPLICATION

Among three tested progestins, chlormadinone acetate had the most consistent suppressive effect on prostaglandins in endometrial explants. These findings support clinical observations about the efficacy of chlormadinone acetate in dysmenorrhea treatment.

[Immunohistochemical predictors of recurrent ovarian endometriomas after laparoscopic surgery]

OBJECTIVE

To investigate the expression of proliferation and apoptotic factors (Ki-67, Bcl-2), inflammatory factors (NF-kβ p65, COX-2), adhesion factors (β-catenin), estrogen (ER-α) and progesterone receptors (PR-α) in ovarian endometrioma (OE) in patients with recurrent OE by an immunohistochemical assay.

SUBJECT AND METHODS

This investigation enrolled 48 reproductive-aged patients with OE. According to the course of the disease during a follow-up period of 1.5 years after surgical treatment, the biomaterial obtained from the examined patients was divided into two groups: 1) an OE capsule from 19 patients with recurrent OE (a study group); 2) an OE capsule from 28 patients without recurrent OE (a comparison group). This investigation used histological and immunohistochemical examinations. The histological analysis of the OE capsule was performed following a standard procedure. Their immunohistochemical analysis was carried out using the Tissue-Tek Quick-Ray kit that allows the preparation of paraffin blocks with a large number of tissue samples (tissue microarrays). Antibodies to Ki-67 (clone 30-9, VENTANA), Bcl-2 (clone 124, VENTANA), NF-kβ p65 (clone p65, 'Spring Bioscience Corp.'), COX-2 (clone CX-294, Agilent), β-catenin (clone 14, VENTANA), ER-α (clone SP1, VENTANA), and PR-α (clone 1E2, VENTANA) were also employed in the investigation. The specimens were prepared according to a standard protocol using a Ventana Ultra immunohistostainer. Positive and negative controls were used to correctly carry out immunohistochemical tests. Statistical analysis was performed using the applied statistical analysis programs Statistica 10.0 and Microsoft Excel.

RESULTS

The patients with recurrent OE had a significantly decreased expression of Ki-67 (2.86% vs. 9.69%; р=0.044) in the epithelial component of the OE capsule; a significantly lower expression of NF-kβ p65 (2.54 vs. 3.5; р=0.0082) and СОХ-2 (0.231 vs. 1.381; р=0.0025) in the stromal component of the OE capsule, a significantly increased expression of β-catenin (2.5 vs. 1.59; р=0.017) in the stromal component of the OE capsule; a significantly increased expression of PR-α (188.46 vs. 71.15; р=0.028) in the epithelial component of an OE capsule. The expression of ER-α (stromal component, 266 vs. 256.84; p=0.48; epithelial component, 251.54 vs. 233.85, p=0.82) and Bcl-2 (stromal component, 0.33 vs. 0.25; p=0.85; epithelial component, 0.944 vs. 0.625; p=0.31) in the OE capsule is not statistically significantly different between the study patient groups.

CONCLUSION

The immunohistochemical difference in the expression of a number of the markers under study can serve as the basis for a further investigation of these markers as predictors of recurrent OE after surgical treatment. Further investigations of these factors will also be able to examine the molecular mechanisms underlying the pathogenesis of recurrent OE, which will make it possible to affect these mechanisms in order to eliminate the fundamental causes of a recurrence of this disease.

Discovery of Phosphatidic Acid, Phosphatidylcholine, and Phosphatidylserine as Biomarkers for Early Diagnosis of Endometriosis

The sensitivity and specificity of clinical diagnostic indicators and non-invasive diagnostic methods for endometriosis at early stage is not optimal. Previous studies demonstrated that abnormal lipid metabolism was involved in the pathological development of endometriosis. Our cross-sectional study included 21 patients with laparoscopically confirmed endometriosis at stage I–II and 20 infertile women who underwent diagnostic laparoscopy combined with hysteroscopy from January 2014 to January 2015. Eutopic endometrium was collected by pipelle endometrial biopsy. Lipid metabolites were quantified by ultra-high performance liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry (UHPLC-ESI-HRMS). Lipid profiles of endometriosis patients at early stage (I–II) was characterized by a decreased concentration of phosphatidylcholine (18:1/22:6), (20:1/14:1), (20:3/20:4), and phosphatidylserine (20:3/23:1) and an increased concentration of phosphatidic acid (25:5/22:6) compared with control. The synthesized predicting strategy with 5 biomarkers has a specificity of 75.0% and a sensitivity of 90.5%. Lipid profile of eutopic endometrium in endometriosis was effectively characterized by UHPLC-ESI-HRMS-based metabolomics. Our study demonstrated the alteration of phosphatidic acid, phosphatidylcholine, phosphatidylserine metabolites in endometriosis and provided potential biomarkers for semi-invasive diagnose of endometriosis at early stage.

Induction of Endometriosis in Nude Mice by Transplantation of Human Peritoneal Endometriotic Tissue

Purpose

Ectopic endometrial tissue is biochemically and functionally distinct from eutopic endometrium, including differences in receptivity to steroids and invasive potential. For this reason, using ectopic endometrial tissue to induce endometriosis in animal models may be of interest to understand better the pathogenesis of this disease. The aim of this study was to evaluate the potential of human pelvic endometriotic lesions (specifically red lesions) to implant into the peritoneal cavity of nude mice.

Methods

Human peritoneal endometriotic tissue (red lesions) was injected into the pelvic cavity of nude mice. The mice were euthanized after 5 or 14 days, lesions were recovered, and histological analysis was performed. Proliferative activity and neoangiogenesis of lesions were assessed after Ki67 and CD34 immunohistological staining, respectively.

Results

After 5 and 14 days, endometriotic tissue was found to have implanted onto intact mesothelium and reorganized into structured glands and stroma, forming endometriosis-like lesions. These lesions showed considerable proliferative activity and effective neoangiogenesis.

Conclusion

This model represents a promising tool to study in vivo implantation of human ectopic endometrium, which is dissimilar to eutopic endometrium. Moreover, this study shows that glands and stroma detached from red endometriotic lesions are able to implant in other peritoneal sites, as in a metastatic process.

Involvement of Iron, Nuclear Factor-Kappa B (NF-κB) and Prostaglandins in the Pathogenesis of Peritoneal Endometriosis-Associated Inflammation: A Review

Peritoneal endometriosis is a chronic pelvic inflammatory disease, characterized by increased numbers of peritoneal macrophages and their secreted products such as cytokines, growth and angiogenic factors in peritoneal fluid. Inflammation plays a major role in pain and infertility associated with endometriosis, but is also extensively involved in the molecular and cellular processes that lead to peritoneal endometriotic lesion development. Several inflammatory mediators have therefore been studied in the context of endometriosis over the last few years.

The aim of this review is to focus on three that have been clearly implicated in the pathogenesis of endometriosis and may be linked: peritoneal iron metabolism, nuclear factor-kappa B (NF-κB) activation, and prostaglandin biosynthesis.

Peritoneal iron overload has been conclusively demonstrated in endometriosis patients and may induce oxidative stress in the peritoneal cavity. Oxidative stress and proinflammatory cytokines are well known to be potent activators of the NF-κB pathway, which has recently been implicated in peritoneal endometriosis. Induced NF-κB activation leads to expression of numerous proinflammatory genes such as cytokines, which may provide positive feedback to the pathway, self-perpetuating the inflammatory response. Other important NF-κB-regulated molecules are prostaglandin biosynthesis enzymes, and cyclooxygenase-2 (COX-2) in particular. Increased concentrations of prostaglandins have been evidenced in the peritoneal fluid of endometriosis patients and COX-2 inhibitors have proved to be effective in ‘in vitro’ and ‘in vivo’ experimental models.

In the light of available data collected from patient biopsies, as well as ‘in vitro’ and ‘in vivo’ studies, the respective implication and potential molecular association of iron, NF-κB and prostaglandins in the pathogenesis of endometriosis are discussed. The key role of peritoneal macrophages is emphasized and potential therapeutic targets are examined.

The Expression of Toll-like receptors in eutopic and ectopic endometrium and its implication in the inflammatory pathogenesis of adenomyosis

In this study, we investigated the expression profiles of Toll-like receptors(TLRs) in eutopic endometrium(EU) and ectopic endometrium(EC) and its implication in the inflammatory pathogenesis of adenomyosis. Thirty adenomyosis patients who underwent laparoscopy were recruited in this study. We tested the mRNA and protein expression of TLRs, and the mRNA expression of IL-6 and IL-8 in EU and EC of adenomyosis patients, and control endometrium without adenomyosis(CE). We found that the mRNA expression of IL-6 and IL-8 in EU was significantly higher than that in CE, and was the highest in EC (P < 0.01). The mRNA and protein expression of TLRs were higher in EU, with the expression of TLR1-6, 8 and 9 being significantly higher in EU than in CE, and were the highest in EC (except TLR6) (P < 0.05 or P < 0.01). Pearson correlation analysis showed that the expression of TLR1, 2, 4, 5 and 9 in EU and EC was positively correlated with that of IL-6 and IL-8 (P < 0.00139). This study suggested that adenomyosis was a state of inflammatory pathology. High expression of TLRs in EU and EC were positively correlated with IL-6 and IL-8, which may be involved in the inflammatory pathogenesis of adenomyosis.

Combination therapy with telmisartan and parecoxib induces regression of endometriotic lesions

BACKGROUND AND PURPOSE

Telmisartan suppresses the development of endometriotic lesions. However, the drug also up-regulates the expression of COX-2, which has been suggested to promote the progression of endometriosis. Accordingly, in the present study we analysed whether a combination therapy with telmisartan and a COX-2 inhibitor may be more effective in the treatment of endometriotic lesions than the application of telmisartan alone.

EXPERIMENTAL APPROACH

Endometriotic lesions were induced in the peritoneal cavity of C57BL/6 mice, which were treated daily with an i.p. injection of telmisartan (10 mg·kg^-1 ), parecoxib (5 mg·kg^-1 ), a combination of telmisartan and parecoxib or vehicle. Therapeutic effects on lesion survival, growth, vascularization, innervation and protein expression were studied over 4 weeks by high-resolution ultrasound imaging as well as immunohistochemical and Western blot analyses.

KEY RESULTS

Telmisartan-treated lesions exhibited a significantly reduced lesion volume when compared with vehicle-treated controls and parecoxib-treated lesions. This inhibitory effect of telmisartan was even more pronounced when it was used in combination with parecoxib. The combination therapy resulted in a reduced microvessel density as well as lower numbers of proliferating Ki67-positive cells and higher numbers of apoptotic cleaved caspase-3-positive stromal cells within the lesions. This was associated with a lower expression of COX-2, MMP-9 and p-Akt/Akt when compared with controls. The application of the two drugs further inhibited the ingrowth of nerve fibres into the lesions.

CONCLUSIONS AND IMPLICATIONS

Combination therapy with telmisartan and a COX-2 inhibitor represents a novel, effective pharmacological strategy for the treatment of endometriosis.

EP2 receptor antagonism reduces peripheral and central hyperalgesia in a preclinical mouse model of endometriosis

Endometriosis is an incurable gynecological disorder characterized by debilitating pain and the establishment of innervated endometriosis lesions outside the uterus. In a preclinical mouse model of endometriosis we demonstrated overexpression of the PGE₂-signaling pathway (including COX-2, EP₂, EP₄) in endometriosis lesions, dorsal root ganglia (DRG), spinal cord, thalamus and forebrain. TRPV1, a PGE₂-regulated channel in nociceptive neurons was also increased in the DRG. These findings support the concept that an amplification process occurs along the pain neuroaxis in endometriosis. We then tested TRPV1, EP₂, and EP₄ receptor antagonists: The EP₂ antagonist was the most efficient analgesic, reducing primary hyperalgesia by 80% and secondary hyperalgesia by 40%. In this study we demonstrate reversible peripheral and central hyperalgesia in mice with induced endometriosis.

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

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

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.

Early pregnancy modulates survival and apoptosis pathways in the corpus luteum in sheep

The corpus luteum (CL) is a transient endocrine gland. Functional and structural demise of the CL allows a new estrous cycle. On the other hand, survival of CL and its secretion of progesterone are required for the establishment of pregnancy. Survival or apoptosis of the luteal cells is precisely controlled by interactions between survival and apoptosis pathways. Regulation of these cell signaling components during natural luteolysis and establishment of pregnancy is largely unknown in ruminants. The objective of the present study was to determine the regulation of survival and apoptosis signaling protein machinery in the CL on days 12, 14, and 16 of the estrous cycle and pregnancy in sheep. Results indicate that: i) expressions of p-ERK1/2, p-AKT, β-catenin, NFκB -p65, -p50, -p52, p-Src, p-β -arrestin, p-GSK3β, X-linked inhibitor of apoptosis protein (XIAP), and p-CREB proteins are suppressed during natural luteolysis; in contrast, their expressions are sustained or increased during establishment of pregnancy; ii) expressions of cleaved caspase-3, apoptosis inducing factor (AIF), c-Fos, c-Jun, and EGR-1 proteins are increased during natural luteolysis; in contrast, their expressions are decreased during establishment of pregnancy; and iii) expressions of Bcl-2, Bcl-XL, Bad, and Bax proteins are not modulated during natural luteolysis while expressions of Bcl2 and Bcl-XL proteins are increased during establishment of pregnancy in sheep. These proteomic changes are evident in both large and small luteal cells. These results together indicate that regression of the CL during natural luteolysis or survival of the CL during establishment of pregnancy is precisely controlled by distinct programmed suppression or activation of intraluteal cell survival and apoptosis pathways in sheep/ruminants.

Abnormal Expression of Prostaglandins E2 and F2α Receptors and Transporters in Patients with Endometriosis

Objective. To investigate the level of expression of prostaglandin receptivity and uptake factors in eutopic and ectopic endometrium of women with endometriosis. Design. Prospective study. Setting. Human reproduction research laboratory. Patients. Seventy-eight patients with endometriosis and thirty healthy control subjects. Intervention(s). Endometrial and endometriotic tissue samples were obtained during laparoscopic surgery. Main Outcome Measure(s). Real-time polymerase chain reaction assay of mRNA encoding prostaglandin E2 receptors (EP1, EP2, EP3, and EP4), prostaglandin F2α receptor (FP), prostaglandin transporter (PGT), and multidrug resistance-associated protein 4 (MRP4); immunohistochemical localization of expressed proteins. Results. Marked increases in receptors EP3, EP4, and FP and transporters PGT and MRP4 in ectopic endometrial tissue were noted, without noticeable change associated with disease stage. An increase in EP3 expression and decreases in FP and PGT were observed in the eutopic endometrium of endometriosis patients in conjunction with the phases of the menstrual cycle. Conclusion(s). This study is the first to demonstrate a possible relationship between endometriosis and enhanced prostaglandin activity. In view of the wide range of prostaglandin functions, increasing cell receptivity and facilitating uptake in endometrial tissue could contribute to the initial steps of overgrowth and have an important role to play in the pathogenesis and symptoms of this disease.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 modulates DNA methylation and histone modification machinery proteins in human endometriotic cells

Endometriosis is an inflammatory gynecological disease of reproductive-age women. The prevalence of endometriosis is 5-10% in reproductive-age women. Modern medical treatments are directed to inhibit the action of estrogen in endometriotic cells. However, hormonal therapies targeting estrogen can be prescribed only for a short time because of their undesirable side effects. Recent studies from our laboratory, using human endometriotic epithelial cell line 12Z and stromal cell line 22B derived from red lesion, discovered that selective inhibition of prostaglandin E2 (PGE2) receptors EP2 and EP4 inhibits adhesion, invasion, growth, and survival of 12Z and 22B cells by modulating integrins, MMPs and TIMPs, cell cycle, survival, and intrinsic apoptotic pathways, suggesting multiple epigenetic mechanisms. The novel findings of the present study indicate that selective pharmacological inhibition of EP2 and EP4: (i) decreases expression of DNMT3a, DNMT3b, H3K9me3, H3K27me3, SUV39H1, HP1a, H3K27, EZH2, JMJD2a, HDAC1, HDAC3, MeCP2, CoREST and Sin3A; (ii) increases expression of H3K4me3, H3H9ac, H3K27ac; and (iii) does not modulate the expression of DNMT1, hSET1, LSD1, MBD1, p300, HDAC2, and JMJD3 epigenetic machinery proteins in an epithelial and stromal cell specific manner. In this study, we report for the first time that inhibition of PGE2-EP2/EP4 signaling modulates DNA methylation, H3 histone methylation and acetylation, and epigenetic memory machinery proteins in human endometriotic epithelial cells and stromal cells. Thus, targeting EP2 and EP4 receptors may emerge as long-term nonsteroidal therapy for treatment of active endometriotic lesions in women.

Anti-inflammatory, antiangiogenic, and apoptosis-inducing activity of DLBS1442, a bioactive fraction of Phaleria macrocarpa, in a RL95-2 cell line as a molecular model of endometriosis

DLBS1442 is a bioactive fraction extracted from the fruit of the native Indonesian plant, Phaleria macrocarpa (Scheff.) Boerl (Thymelaceae). This bioactive fraction is a potential treatment for dysmenorrhea and endometriosis. The present study investigated the pharmacological action of DLBS1442 in endometrial cells. The effect of various doses of DLBS1442 (0–200 μg/mL) over 24 hours was studied using the human endometrial RL95-2 cell line to observe its effect on angiogenesis, cell migration, estrogen and progesterone receptor levels, the eicosanoid pathway, cell viability, and apoptosis. The impact of DLBS1442 on nuclear factor kappa B (NFκB) and the eicosanoid pathway was also studied through its marker gene expression using a quantitative real-time polymerase chain reaction method. DLBS1442 showed an ability to inhibit angiogenesis and cell migration in a dose-dependent manner. At a dose of 100 μg/mL, DLBS1442 increased the cell population in sub-G1 phase from 7% to 34%. DLBS1442 also significantly downregulated the estrogen receptor level and upregulated the progesterone receptor level. Further, it inhibited the eicosanoid signaling pathway by reducing the NFκB transcription level and subsequent reduction of inducible nitric oxide synthase. A dose-dependent decrease in viability and increased apoptosis in RL95-2 cells were also evident after exposure to DLBS1442, where the IC₅₀ was obtained at around 100 μg/mL. In conclusion, DLBS1442 is a potential agent for alleviating symptoms of endometriosis via its antiangiogenic, anti-inflammatory, and proapoptotic activity.

Macrophage migration inhibitory factor is involved in ectopic endometrial tissue growth and peritoneal-endometrial tissue interaction in vivo: a plausible link to endometriosis development

Pelvic inflammation is a hallmark of endometriosis pathogenesis and a major cause of the disease's symptoms. Abnormal immune and inflammatory changes may not only contribute to endometriosis-major symptoms, but also contribute to ectopic endometrial tissue growth and endometriosis development. A major pro-inflammatory factors found elevated in peritoneal fluid of women with endometriosis and to be overexpressed in peritoneal fluid macrophages and active, highly vascularized and early stage endometriotic lesions, macrophage migration inhibitory factor (MIF) appeared to induce angiogenic and inflammatory and estrogen producing phenotypes in endometriotic cells in vitro and to be a possible therapeutic target in vivo. Using a mouse model where MIF-knock out (KO) mice received intra-peritoneal injection of endometrial tissue from MIF-KO or syngeneic wild type (WT) mice and vice versa, our current study revealed that MIF genetic depletion resulted in a marked reduction ectopic endometrial tissue growth, a disrupted tissue structure and a significant down regulation of the expression of major inflammatory (cyclooxygenease-2), cell adhesion (αv and β3 integrins), survival (B-cell lymphoma-2) and angiogenic (vascular endothelial cell growth) factorsrelevant to endometriosis pathogenesis, whereas MIF add-back to MIF-KO mice significantly restored endometriosis-like lesions number and size. Interestingly, cross-experiments revealed that MIF presence in both endometrial and peritoneal host tissues is required for ectopic endometrial tissue growth and pointed to its involvement in endometrial-peritoneal interactions. This study provides compelling evidence for the role of MIF in endometriosis development and its possible interest for a targeted treatment of endometriosis.

CD4+Foxp3+ regulatory T cell differentiation mediated by endometrial stromal cell-derived TECK promotes the growth and invasion of endometriotic lesions

Endometriosis is associated with an abnormal immune response to endometrial cells, which can facilitate the implantation and proliferation of ectopic endometrial tissue. The proportion of CD4(+)Foxp3(+) regulatory T cells (Tregs) is significantly increased in the peritoneal fluid of women with endometriosis. The thymus-expressed chemokine TECK/CCL25 directly promotes the invasiveness of endometrial stromal cells (ESCs). The aim of this study was to investigate the effects of ESC-derived TECK on the crosstalk between Tregs and ESCs in the progress of endometriosis. We determined that the percentage of Tregs and the concentration of TECK increased in the peritoneal fluid with the progression of endometriosis. The supernatant from co-cultured human ESCs and macrophages not only induced Treg differentiation and increased Treg expression of interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and CD73 by activating the AKT/STAT3 signaling pathway but also repressed Treg apoptosis by downregulating Fas and FasL expression and enhanced the Treg-mediated suppression of CD4(+)CD25(-) T cells. In addition, in vitro and in vivo trials confirmed that these effects could be inhibited by anti-TECK neutralizing Abs. The secretion of IL-10 and TGF-β by Tregs increased MMP2 expression and decreased TIMP1 expression and further stimulated the proliferation and invasion of ESCs and the growth of ectopic lesions. These results indicate that TECK derived from ESCs and macrophages upregulates the number and function of Tregs in the ectopic milieu, which contributes to endometriotic immunotolerance and high levels of ESC proliferation and invasion, thereby facilitating the progression of endometriosis.

Resolvins RvD1 and 17(R)-RvD1 alleviate signs of inflammation in a rat model of endometriosis

OBJECTIVE

To study the effects of two resolvins of D series, RvD1 and 17(R)-RvD1, on inflammatory signs associated with endometriosis (ENDO).

DESIGN

In vivo research study.

SETTING

Research laboratory.

ANIMAL(S)

Female Sprague-Dawley rats.

INTERVENTION(S)

Intravenous or intraperitoneal injections of RvD1 (300 ng/kg) or 17(R)-RvD1 (300 and 900 ng/kg) in rats with surgically induced ENDO.

MAIN OUTCOME MEASURE(S)

Vascular permeability of ectopic endometrial growths was assessed by Evans Blue extravasation; vaginal hyperalgesia was assessed with telemetered visceromotor response.

RESULT(S)

Both resolvins, but not vehicle, significantly decreased vascular permeability in ectopic endometrial tissue. 17(R)-RvD1 also significantly alleviated severity of vaginal hyperalgesia.

CONCLUSION(S)

Our results suggest that RvD1 and 17(R)-RvD1 can be considered for further investigation of their therapeutic potential for treating ENDO.