Selective cyclo-oxygenase-2 inhibition induces regression of autologous endometrial grafts by down-regulation of vascular endothelial growth factor-mediated angiogenesis and stimulation of caspase-3-dependent apoptosis

Research Progress of Caspase in Endometriosis

Endometriosis, a common chronic gynecological disease, refers to the presence and proliferation of endometrial tissue in locations other than the uterine cavity. Approximately 6 to 10% of the population of women of childbearing age are known to have endometriosis; the most common clinical signs are pelvic pain and infertility. Although endometriosis is a benign disease, it exhibits some typical features of malignant tumors, such as proliferation, invasion, metastasis, and recurrence. Endometriosis is considered a chronic, inflammatory, and estrogen-dependent disease, and multiple factors contribute to its occurrence and development. In recent years, increasing attention has been given to the role of apoptosis in the pathogenesis of this disease. Some researchers believe that spontaneous apoptosis of the endometrium is critical in maintaining its normal structure and function, and abnormal apoptosis can promote the occurrence and development of endometriosis. Inflammation is another likely process in the pathogenesis of endometriosis. Inflammation mediates the adhesion, proliferation, differentiation, and invasion of ectopic lesions of endometriosis, primarily by regulating the function of immune cells and increasing the level of proinflammatory cytokines in body fluids. The ultimate initiators of apoptosis and inflammatory cell death (pyroptosis) are the caspase family proteases. In this article, we review the progress in recent years in caspase function as well as the possible role of these enzymes in the pathogenesis of endometriosis, indicating potential treatment strategies.

Non-Surgical Interventions for the Prevention of Clinically Relevant Postoperative Pancreatic Fistula-A Narrative Review

Clinically relevant postoperative pancreatic fistula (CR-POPF) is the leading cause of morbidity and mortality after pancreatic surgery. Post-pancreatectomy acute pancreatitis (PPAP) has been increasingly understood as a precursor and exacerbator of CR-POPF. No longer believed to be the consequence of surgical technique, the solution to preventing CR-POPF may lie instead in non-surgical, mainly pharmacological interventions. Five databases were searched, identifying eight pharmacological preventative strategies, including neoadjuvant therapy, somatostatin and its analogues, antibiotics, analgesia, corticosteroids, protease inhibitors, miscellaneous interventions with few reports, and combination strategies. Two further non-surgical interventions studied were nutrition and fluids. New potential interventions were also identified from related surgical and experimental contexts. Given the varied efficacy reported for these interventions, numerous opportunities for clarifying this heterogeneity remain. By reducing CR-POPF, patients may avoid morbid sequelae, experience shorter hospital stays, and ensure timely delivery of adjuvant therapy, overall aiding survival where prognosis, particularly in pancreatic cancer patients, is poor.

Effects of selective inhibition of prostaglandin E2 receptors EP2 and EP4 on the miRNA profile in endometriosis

Endometriosis is an estrogen-dependent, progesterone-resistant, chronic inflammatory gynecological disease of reproductive-age women. Two major clinical symptoms of endometriosis are chronic pelvic pain and infertility, which profoundly affect the quality of life in women. Current hormonal therapies to induce a hypoestrogenic state are unsuccessful because of undesirable side effects, reproductive health concerns, and failure to prevent disease recurrence. Prostaglandin E₂ (PGE₂) plays an important role in the survival and growth of endometriotic lesions. MicroRNAs (miRNAs) are small, noncoding RNAs that control gene expressions through multiple mechanisms and have important roles in the pathogenesis of endometriosis. The objective of the present study is to determine the effects of pharmacological inhibition of PGE₂ receptors, EP2 and EP4, on miRNA profile in endometriosis. The novel results collectively indicate that inhibition of PGE₂-EP2/EP4 signaling regulated several miRNA clusters associated with cell adhesion, migration, invasion, survival and growth in cell-specific and the chromosome-specific manner and reverses the epigenetic silencing of proapoptotic miRNAs 15a and 34c in the human endometriotic epithelial and stromal cells and experimental endometriotic lesions. Thus, selective inhibition of EP2/EP4 receptors could emerge as a potential nonsteroidal therapy for endometriosis.

Presurgical blood metabolites and risk of postsurgical pelvic pain in young patients with endometriosis

OBJECTIVE

To identify metabolites in presurgical blood associated with risk of persistent postsurgical pelvic pain 1 year after endometriosis surgery in adolescent and young adult patients.

DESIGN

Prospective observational study within the Women's Health Study: From Adolescence to Adulthood, a US-based longitudinal cohort of adolescents and women enrolled from 2012-2018.

SETTING

Two tertiary care hospitals.

PATIENT(S)

Laparoscopically confirmed endometriosis patients (n = 180) with blood collected before their endometriosis surgery. Of these, 77 patients additionally provided blood samples 5 weeks to 6 months after their surgery. We measured plasma metabolites using liquid chromatography tandem mass spectrometry, and a total of 390 known metabolites were included in our analysis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Persistent postsurgical pelvic pain, defined as severe, life-impacting pelvic pain 1 year after endometriosis surgery.

RESULT(S)

Most patients (>95%) were at stage I/II of the revised American Society for Reproductive Medicine classification. Their average age at diagnosis was 18.7 years, with 36% reporting persistent postsurgical pelvic pain. Of the 21 metabolites in presurgical blood that were associated with risk of persistent postsurgical pelvic pain, 19 metabolites, which were mainly lipid metabolites, were associated with increased risk. Only 2 metabolites-pregnenolone sulfate (odds ratio = 0.64, 95% confidence interval = 0.44-0.92) and fucose (odds ratio = 0.69, 95% confidence interval = 0.47-0.97)-were associated with decreased risk. Metabolite set enrichment analysis revealed that higher levels of lysophosphatidylethanolamines (false discovery rate = 0.01) and lysophosphatidylcholines (false discovery rate = 0.01) in presurgical blood were associated with increased risk of persistent postsurgical pelvic pain.

CONCLUSION(S)

Our results suggest that dysregulation of multiple groups of lipid metabolites may play a role in the persistence of pelvic pain postsurgery among young endometriosis patients.

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.

Endometriosis, infertility and MicroRNA's: A review

The review aims to explore circulating small non- coding regulatory Ribonucleic Acids (miRNA) as biomarkers of endometriosis; a reproductive age group disorder. miRNA are linked with genetic, epigenetic and angiogenic factors, hormones, cytokines, chemokines, oxidative stress (OS) markers, mediators of inflammation, hypoxia, angiogenesis and altered immune system contributing to the pathogenesis of endometriosis. Hormonal imbalance occurs by decreased levels of miRNAs -23a and miRNAs -23b and increase in miRNAs -:135a, 135b, 29c and 194-3p. Angiogenesis by vascular endothelial growth factor is attributed to increased miRNAs -126, miRNAs -210, miRNAs -21, miRNAs -199a-5p and miRNAs 20A. OS upregulates miRNAs -302a by increased levels of Tumor Necrosis factor (TNF)-α, TNF- β and Interleukin -1β. Upregulation of miRNAs -199a and miRNAs -16 promotes inflammation and cell proliferation in the endometriotic lesions. The gold standard to diagnose endometriosis is laparoscopy, yet miRNA can be validated as diagnostic tool for detection, progression and prevention of endometriosis in large, independent cohorts of women, with and without endometriosis.

Use of selective PGE2 receptor antagonists on human endometriotic stromal cells and peritoneal macrophages

Non-hormonal therapeutic strategies for endometriosis are needed. The aim of this study was to characterize the effects of prostaglandin (PG)E2 receptor inhibitors to explore their potential as novel therapeutic strategies for endometriosis. The expression of PGE2 receptors (EP2 and EP4) in donated tissues from human ovarian endometriosis, adenomyosis and peritoneal endometriosis was examined using immunohistochemistry. Human endometriotic stromal cells (ESC) isolated from ovarian endometriotic tissue and peritoneal macrophages were treated with EP2 and EP4 antagonists. cAMP accumulation and the effect of EP antagonists were measured using cAMP assays. DNA synthesis in ESC was detected using bromodeoxyuridine incorporation analysis. Interleukin (IL)-6 and IL-8 protein levels in ESC supernatants were measured using ELISAs. mRNA expression level for aromatase by ESC, and selected cytokines by peritoneal macrophages was measured using RT-PCR. EP2 and EP4 receptors were expressed in cells derived from control and diseased tissue, ovarian endometriotic, adenomyotic and peritoneal lesions. A selective EP2 antagonist reduced DNA synthesis, cAMP accumulation and IL-1β-induced proinflammatory cytokine secretion and aromatase expression. A selective EP4 antagonist negated IL-1β-induced IL-6 secretion and aromatase expression. In peritoneal macrophages, EP expression was elevated in endometriosis samples but the EP4 antagonist reduced cAMP levels and expression of vascular endothelial growth factor, chemokine ligand 2 and chemokine ligand 3 mRNA. EP2 and EP4 are functioning in endometriosis lesions and peritoneal macrophages, and their selective antagonists can reduce EP-mediated actions, therefore, the EP antagonists are potential therapeutic agents for controlling endometriosis.

Eutopic stromal cells of endometriosis promote neuroangiogenesis via exosome pathway†

Endometriosis is a common multifactorial gynecological disorder defined as the proliferation of endometrial tissue outside of the uterine cavity. Neuroangiogenesis (co-recruitment of nerves and blood vessels) is believed to play an integral part in the establishment and growth of endometriotic lesions. We hypothesized that exosomes derived from abnormal endometrium may serve as the second identifier of endometriosis and play an important role in the development of endometriosis by regulating neuroangiogenesis. Primary human endometrial stromal cells (ESCs) were isolated from eutopic endometrium (EmESC, n = 22) with endometriosis and normal endometrium (CoESC, n = 6). Exosomes were isolated from ESCs using the "standard" ultracentrifugation method, and the characterization of exosomes was identified through transmission electron microscopy, nanoparticle tracking analysis, and western blot. The role of exosomes in regulating neuroangiogenesis was determined through in vitro tube formation assay, neurite outgrowth assay, and dorsal root ganglion (DRG) neuron apoptosis analysis. The data showed that EmESCs could secrete exosomes with a diameter of approximately 100 nm and a biconcave morphological feature; they were internalized by human umbilical vein endothelial cells and DRG neurons and enhanced neuroangiogenic effects. We further validated the role of exosomes through blocking experiments. We found that when the exosome secretion was blocked, the pro-neuroangiogenesis effects were decreased. In conclusion, these data suggested that exosomes may play a key role in endometriosis by promoting neuroangiogenesis.

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.

Dose-Dependent Decreased Fertility in Response to the Burden of Endometriosis in a Murine Model

Endometriosis is a gynecological disease caused by the growth of endometrial cells outside the uterus leading to inflammation, pelvic pain, and infertility. The relationship between the amount of ectopic uterine tissue growth and the severity of symptoms is still unclear. The presence or degree of pain and infertility does not correlate with the stage of disease as currently defined. Here, we report a clear dose-response relationship between the amount of ectopic tissue transplanted and the reproductive outcomes in a murine model of endometriosis. Endometriosis was induced in mice using various amounts of transplanted uterine tissue. Four groups of mice consisted of a sham surgery control or those transplanted with 1, 2, or 4 endometrial segments of 5 mm each. Pregnancy rates were significantly lower in those transplanted with 2 or 4 segments compared to sham or the 1 segment groups. We demonstrate that infertility does correlate with the extent of active disease. Current clinical staging systems do not account for disease activity and may inappropriately weight sequela of disease. Early recognition and treatment in women may help to minimize the effect of endometriosis on fertility. Here, we describe a mouse model of endometriosis and infertility that may be useful to elucidate the mechanisms of infertility in endometriosis.

A murine model to study vasoreactivity and intravascular flow in lung isograft microvessels

Intravital microscopy of orthotopic lung tissue is technically demanding, especially for repeated investigations. Therefore, we have established a novel approach, which allows non-invasive repetitive in vivo microscopy of ectopic lung tissue in dorsal skinfold chambers. Syngeneic subpleural peripheral lung tissue and autologous endometrium (control) were transplanted onto the striated muscle within dorsal skinfold chambers of C57BL/6 mice. Grafts were analysed by intravital fluorescence microscopy over 14 days. Angiogenesis occurred in the grafts on day 3, as indicated by sinusoidal microvessels on the grafts’ edges with very slow blood flow, perifocal oedema, and haemorrhage. By day 10, lung transplants were completely revascularized, exhibited a dense network of microvessels with irregular diameters, chaotic angioarchitecture, and high blood flow. Compared to lung tissue, endometrial grafts contained a structured, glomerulus-like vessel architecture with lower blood flow. Despite missing ventilation, hypoxic vasoconstriction of the lung tissue arterioles occurred. In contrast, endometrium tissue arterioles dilated during hypoxia and constricted in hyperoxia. This demonstrates that ectopic lung grafts keep their ability for organ-specific hypoxic vasoconstriction. These findings indicate that our approach is suitable for repetitive in vivo pulmonary microcirculation analyses. The high blood flow and hypoxia-induced vasoconstriction in lung grafts suggest a physiological intrinsic vasoregulation independent of the recipient tissue.

Comparing The Effects of Glycyrrhiza glabra Root Extract, A Cyclooxygenase-2 Inhibitor (Celecoxib) and A Gonadotropin-Releasing Hormone Analog (Diphereline) in A Rat Model of Endometriosis

Background

The purpose of this study was to compare the effects of Glycyrrhiza glabra (Licorice), a cyclooxyge- nase-2 inhibitor (Celecoxib) and a gonadotropin-releasing hormone analog (Diphereline®), with a control group on endometrial implants in rats.

Materials and Methods

In this experimental study, endometriosis was induced in rats by auto transplantation and after confirmation, the rats were divided into 4 groups that were treated for 6 weeks with normal saline (0.5 ml/day, orally), licorice extract (3000 mg/kg/day, orally), celecoxib (50 mg/kg, twice a day, orally) or diphereline (3 mg/kg, intramuscularly). At the end of treatments, the mean area, volume, histopathology and hemosiderin-laden macrophage (HLM) counts of the endometrial implants were evaluated and compared among the four groups.

Results

The mean area, volume and HLM counts of the implants in the licorice group were significantly lower than those of the control group (P<0.001). The histopathologic grades of endometrial implants were significantly decreased by licorice compared to the control group (P<0.001). There was no significant change in the mentioned parameters in rats treated with celecoxib compared to the control group. Diphereline was the most potent agent for suppressing the growth of endometrial implants in terms of all of the above-mentioned parameters.

Conclusion

Licorice decreased the growth and histopathologic grades of auto-transplanted endometrial implants. However, while celcoxib had no significant effect, diphereline showed the highest potency for decreasing the endome- trial growth. Licorice may have the potential to be used as an alternative medication for the treatment of endometriosis.

6-Shogaol reduces progression of experimental endometriosis in vivo and in vitro via regulation of VGEF and inhibition of COX-2 and PGE2-mediated inflammatory responses

Endometriosis (EM) is one of the most common gynaecological disorder affecting women in their reproductive age. Mechanisms involved in the pathogenesis of EM remains poorly understood, however inflammatory responses have been reported to be significantly involved. The efficacy of 6-shogaol on proliferation of endometriotic lesions and inflammatory pathways in experimentally-induced EM model was explored in this study. EM was stimulated in Sprague-Dawley rats by implantation of autologous endometrium onto the peritoneum abdominal wall. Separate groups were treated with 6-shogaol (50, 100 or 150 mg/kg b.wt/day) via oral gavage for one month period. Gestrinone (GTN) group received GTN (0.5 mg/kg/day) as positive control. Five weeks after implantation, the spherical volume of ecto-uterine tissues was determined. Treatment with 6-shogaol significantly reduced the implant size. Histological analysis reported atrophy and regression of the lesions. 6-shogaol administration effectively down-regulated NF-κB signaling, VEGF and VEGFR-2 (Flk-1) expression in the endometriotic lesions. Excess production of IL-1β and IL-6 (pro-inflammatory cytokines), PGE2 and nitric oxide (NO) were reduced. Overall, the results of the study reveal the efficacy of 6-shogaol against endometriosis via effectively suppressing proliferation of the lesions and modulating angiogenesis and COX-2/NF-κB-mediated inflammatory cascades.

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.

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.

Targeting hypoxia-mediated YAP1 nuclear translocation ameliorates pathogenesis of endometriosis without compromising maternal fertility

Endometriosis is a highly prevalent gynaecological disease that severely reduces women's health and quality of life. Ectopic endometriotic lesions have evolved mechanisms to survive in the hypoxic peritoneal microenvironment by regulating the expression of a significant subset of genes. However, the master regulator controlling these genes remains to be characterized. Herein, by using bioinformatics analysis and experimental verification, we identified yes-associated protein 1 (YAP1) as a master regulator of endometriosis. Nuclear localization and transcriptional activity of YAP1 were up-regulated by hypoxia via down-regulation of LATS1, a kinase that inactivates YAP1. Disruption of hypoxia-induced YAP1 signalling by siRNA knockdown or inhibitor treatment abolished critical biological processes involved in endometriosis development such as steroidogenesis, angiogenesis, inflammation, migration, innervation, and cell proliferation. Treatment with a YAP1 inhibitor caused the regression of endometriotic lesions without affecting maternal fertility or the growth rate of offspring in the mouse model of endometriosis. Taken together, we identify hypoxia/LATS1/YAP1 as a novel pathway for the pathogenesis of endometriosis and demonstrate that targeting YAP1 might be an alternative approach to treat endometriosis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Summary of Future Developments

Endometriosis is a chronic disease with the potential to cause devastating clinical manifestations such as infertility and chronic pelvic disease. Current treatment is limited to surgical intervention and pharmacologic therapy targeting estrogen and progesterone to suppress ectopic endometrial tissue proliferation. Undesired side effects and contraindications to the use of hormonal medications may reduce treatment options. As the pathogenesis of endometriosis continues to be investigated, new therapies will emerge. The identification of genes involved in the development of endometriosis may allow targeted therapy to prevent or cure disease. In addition, increasing knowledge of the inflammatory pathways that promote ectopic endometrial growth will permit the development of pharmacologic agents to manipulate these signaling pathways. Utilization of selective progesterone receptor modulators, aromatase inhibitors, and modern gonadotropin-releasing hormone antagonists provide more options to manage disease when traditional treatment fails. Individualized therapeutic strategies will soon be a reality as a greater understanding of endometriosis is obtained through the investigation of genomic studies, molecular pathways, and environmental influences.

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.

Euterpe oleracea Extract (Açaí) Is a Promising Novel Pharmacological Therapeutic Treatment for Experimental Endometriosis

This study investigated the therapeutic potential of Euterpe oleracea extract (açaí) on the growth and survival of endometriotic lesions using an experimental model. Twenty female Sprague-Dawley rats were randomized into two groups after the implantation and establishment of autologous endometrium onto the peritoneum abdominal wall and treated with 200 mg/kg hydroalcoholic solution extract from açaí stone or vehicle via gastric tube for 30 consecutive days. Body weight, lesion surface areas, histological and immunohistochemistry analyses of vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), metalloproteinase-9 (MMP-9), cyclooxygenase-2 (COX-2) and F4-80 were performed. Levels of VEGF, VEGFR-2, MMP-9 and COX-2 mRNA were measured. Flow cytometry of F4-80 was performed, and ELISA immunoassays measured prostaglandin E₂ (PGE₂), VEGF and nitric oxide (NO) and concentrations. Macrophage cell line J774.G8 was treated with 10, 20, and 40 μg/mL of açaí for 24, 48 and 72 h, and cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Açaí treatment significantly decreased the implant size, and histological examination indicated atrophy and regression. A reduction in immunostaining and mRNA expression of VEGF, MMP-9 and COX-2 was observed, and F4-80 was lower in the treated group than the control group. The treated group also exhibited lower concentrations of PGE₂, VEGF and NO compared to the control group. Macrophages cells treated with 20 and 40 μg/ml of açaí reduced cell viability in about 50% after 24, 48 and 72 h. Our results suggest that açaí effectively suppressed the establishment and growth of endometriotic lesions, and this agent is a promising novel pharmacological therapeutic treatment for endometriosis.

Comparison between resveratrol and cabergoline in preventing ovarian hyperstimulation syndrome in a rat model

OBJECTIVE

The aim of this study is to investigate the effects of resveratrol in a rat model of ovarian hyperstimulation syndrome (OHSS) and compare with cabergoline.

DESIGN

Randomized controlled, animal study.

ANIMAL(S)

Female Wistar rats.

MATERIAL AND METHODS

A rat OHSS model was used to investigate the effects of resveratrol compare with cabergoline administration for preventing OHSS. Body weight, ovary weight, diameter, vascular permeability (VP), vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) expression (immunohistochemistry), and serum estradiol (E2) levels were then compared.

RESULTS

The ovarian VEGF concentration was significantly increased in the OHSS Groups (Groups 3-5) compared with the control groups (1 and 2). But vascular permeability, VEGF, and COX-2 expressions were reduced in animals treated with the resveratrol group compared with the cabergoline group (group 5) and the severe OHSS (group 3) group. Blood E2 levels were decreased in group treated with the resveratrol group compared with the cabergoline group (group 5) and severe the OHSS (group 3) group.

CONCLUSION(S)

Our results in a rat model suggest that resveratrol has a beneficial effect on OHSS by reducing the increases in ovarian daimeter, VP, and VEGF expression associated with OHSS. These effects may be mediated by the COX-2 inhibitory capacity of resveratrol.

Inhibition of Hyaluronic Acid Synthesis Suppresses Angiogenesis in Developing Endometriotic Lesions

Background

The development and long-term survival of endometriotic lesions is crucially dependent on an adequate vascularization. Hyaluronic acid (HA) through its receptor CD44 has been described to be involved in the process of angiogenesis.

Objective

To study the effect of HA synthesis inhibition using non-toxic doses of 4-methylumbelliferone (4-MU) on endometriosis-related angiogenesis.

Materials and Methods

The cytotoxicity of different in vitro doses of 4-MU on endothelial cells was firstly tested by means of a lactate dehydrogenase assay. The anti-angiogenic action of non-cytotoxic doses of 4-MU was then assessed by a rat aortic ring assay. In addition, endometriotic lesions were induced in dorsal skinfold chambers of female BALB/c mice, which were daily treated with an intraperitoneal injection of 0.9% NaCl (vehicle group; n = 6), 20mg/kg 4-MU (n = 8) or 80mg/kg 4-MU (n = 7) throughout an observation period of 14 days. The effect of 4-MU on their vascularization, survival and growth were studied by intravital fluorescence microscopy, histology and immunohistochemistry.

Main Results

Non-cytotoxic doses of 4-MU effectively inhibited vascular sprout formation in the rat aortic ring assay. Endometriotic lesions in dorsal skinfold chambers of 4-MU-treated mice dose-dependently exhibited a significantly smaller vascularized area and lower functional microvessel density when compared to vehicle-treated controls. Histological analyses revealed a downregulation of HA expression in 4-MU-treated lesions. This was associated with a reduced density of CD31-positive microvessels within the lesions. In contrast, numbers of PCNA-positive proliferating and cleaved caspase-3-positive apoptotic cells did not differ between 4-MU-treated and control lesions.

Conclusions

The present study demonstrates for the first time that targeting the synthesis of HA suppresses angiogenesis in developing endometriotic lesions. Further studies have to clarify now whether in the future this anti-angiogenic effect can be used beneficially for the treatment of endometriosis.

Recent advances in the understanding of endometriosis: the role of inflammatory mediators in disease pathogenesis and treatment

In this review, we focus on recent advancements in our understanding of the roles of inflammatory mediators in endometriosis pathophysiology and the potential for improved therapies based upon targeting these pathways. We review the association between endometriosis and inflammation and the initial promise of anti-tumor necrosis factor therapies based upon experimental evidence, and how and why these studies have not translated to the clinic. We then discuss emerging data on the role of inter-relationship among macrophage migration inhibitory factor, prostaglandin E ₂, and estrogen receptor-beta, and the potential utility of targeting these factors in endometriosis treatment. In doing so, we highlight the strengths and discuss the current research on identification of novel, anti-inflammatory-based therapy and the necessity to expand experimental endpoints to include clinically relevant measures when assessing the efficacy of potential new therapies for endometriosis.

MAP kinases and the inflammatory signaling cascade as targets for the treatment of endometriosis?

INTRODUCTION

The pathogenesis of endometriosis, a common benign disease, remains ill-defined, although it is clear that chronic inflammation plays a crucial role through mitogen-activated protein kinase (MAPK) signaling pathways. All current medical therapies for endometriosis are antigonadotropic, and therefore have a contraceptive effect. A concerted research effort is hence warranted with the aim of delivering novel therapeutics that reduces disease symptoms without blocking ovulation.

AREAS COVERED

The authors review the complex pathogenic mechanisms of chronic inflammation in endometriosis and their relationships with MAPK pathways. The authors conducted a literature search of descriptive and functional targeted validation of MAPK in the pathogenesis of endometriosis. The effects of MAPK inhibitors, which constitute potential agents for future treatments, are also described.

EXPERT OPINION

Preliminary studies have highlighted a crucial role for MAPK in driving endometriosis-related inflammation. MAPK inhibitors exhibit potent activity in terms of controlling growth of endometriosis lesions both in vitro and in animal models. As MAPK inhibitors are known to have a multitude of undesirable side effects, their use in humans has to be approached with great care. Indeed, use of these drugs would probably be limited to short exposures prior to surgery in cases involving the most severe disease phenotypes.

The Effect of Early Postoperative Non-Steroidal Anti-Inflammatory Drugs on Pancreatic Fistula Following Pancreaticoduodenectomy

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are used commonly for postoperative analgesia but can potentially impair healing. Their effect on pancreaticoduodenectomy (PD) outcomes is unknown. We sought to examine the impact of early postoperative NSAIDs on pancreatic fistula (PF) after PD.

METHODS

We reviewed our prospective pancreatectomy database supplemented by medication administration records, including all PDs from 2002 to 2012. Primary outcome was occurrence of clinically significant (grade B-C) PF. Secondary outcomes included major morbidity (Clavien grade III-V) and 90-day mortality. Patients were compared based on early postoperative NSAID use (first 3 days following surgery) using univariate and multivariate analyses. Subgroup analyses were conducted based on NSAID type (COX-2 inhibitors and non-selective inhibitors).

RESULTS

We included 251 PDs, of whom 127 (50.6%) patients received NSAIDs postoperatively (35.5% COX-2 inhibitors, 18.3% non-selective inhibitors, and 4.4% both). Use of any NSAIDs was associated with a non-significant increase in PF (16.5 vs 11.3%%; p = 0.23), and no difference in major morbidity and mortality. Use of non-selective inhibitors was not associated with an increase in PF (8.7 vs 15.1%; p = 0.256). COX-2 inhibitors were associated with increased PF (20.2 vs 10.5 %; p = 0.033), but no difference in major morbidity or mortality. After adjusting for Charlson comorbidity and estimated blood loss, use of COX-2 inhibitors was independently associated with PF (odds ratio 2.12; p = 0.044).

CONCLUSIONS

COX-2 inhibitors are associated with PF in the early postoperative period. While non-selective inhibitors appear safe in this setting, caution is warranted with the use of COX-2 inhibitors.

Molecular and preclinical basis to inhibit PGE2 receptors EP2 and EP4 as a novel nonsteroidal therapy for endometriosis

Endometriosis is a debilitating, estrogen-dependent, progesterone-resistant, inflammatory gynecological disease of reproductive age women. Two major clinical symptoms of endometriosis are chronic intolerable pelvic pain and subfertility or infertility, which profoundly affect the quality of life in women. Current hormonal therapies to induce a hypoestrogenic state are unsuccessful because of undesirable side effects, reproductive health concerns, and failure to prevent recurrence of disease. There is a fundamental need to identify nonestrogen or nonsteroidal targets for the treatment of endometriosis. Peritoneal fluid concentrations of prostaglandin E2 (PGE2) are higher in women with endometriosis, and this increased PGE2 plays important role in survival and growth of endometriosis lesions. The objective of the present study was to determine the effects of pharmacological inhibition of PGE2 receptors, EP2 and EP4, on molecular and cellular aspects of the pathogenesis of endometriosis and associated clinical symptoms. Using human fluorescent endometriotic cell lines and chimeric mouse model as preclinical testing platform, our results, to our knowledge for the first time, indicate that selective inhibition of EP2/EP4: (i) decreases growth and survival of endometriosis lesions; (ii) decreases angiogenesis and innervation of endometriosis lesions; (iii) suppresses proinflammatory state of dorsal root ganglia neurons to decrease pelvic pain; (iv) decreases proinflammatory, estrogen-dominant, and progesterone-resistant molecular environment of the endometrium and endometriosis lesions; and (v) restores endometrial functional receptivity through multiple mechanisms. Our novel findings provide a molecular and preclinical basis to formulate long-term nonestrogen or nonsteroidal therapy for endometriosis.

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.

A rare case of endometrioma in a bitch

Background

Endometriosis is ectopic development of endometrial glands and stroma in extra-uterine sites and if the lesions occur as a well-defined mass is referred to as endometrioma. In the literature, endometrioma has been reported in only women and there are no reports of endometrioma in animals, including non-human primates.

Case presentation

A rare case of endometrioma is reported in an 11-year-old female German Shepherd with clinical signs of dehydration, anemia and prostration. Necropsy revealed ascites, generalized pallor, and a well-demarcated reddish mass adjacent to the left ovary and uterus and adherent to the retroperitoneum. The mass measured 25.0 × 20.0 cm with intermingled soft and firm areas. Upon incision, the mass was found to be solid with variable sized cystic cavities filled with coagulated blood. Microscopically, the mass was composed of cuboidal or prismatic epithelial cells arranged in tubules or acini. The epithelium of the mass had similar characteristics to the normal endometrium with PAS-positive secretions. The stroma was prominent and formed by loose connective tissue and smooth muscle fibers as confirmed by Masson trichrome. Extensive multifocal areas of hemorrhage were also observed in the stroma of the mass and in the interior of some epithelium-lined, cystic structures. Most of the epithelial cells had strong and diffuse cytokeratin expression, and some had vimentin expression. Epithelial and stromal cells also showed ERβ, AR, VEGF and COX2 expression. The stroma showed areas with strong and diffuse vimentin expression. Factor VIII expression was observed only in the endothelium of blood vessels in the stroma.

Conclusions

The macroscopic, microscopic and immunohistochemical findings are consistent with an endometrioma.

[Interaction of anesthetics and analgesics with tumor cells]

The results of preclinical and clinical studies indicate that the perioperative period is a vulnerable period for cancer progression and metastasis. The risk of cancer cell dissemination is enhanced by the combination of surgical manipulation and perioperative immunosuppression. Whether the oncological outcome of cancer patients can be influenced by the choice of anesthetic techniques is still a matter of debate. This review summarizes the molecular characteristics of cancer and interaction of anesthetic and analgesic drugs with cancer cells.

CD26/DPPIV down-regulation in endometrial stromal cell migration in endometriosis

OBJECTIVE

To test the hypothesis that endometrial stromal cells (ESCs) in endometriosis exhibit increased cell motility under hypoxia.

DESIGN

Prospective case-control study.

SETTING

University research laboratory.

PATIENT(S)

Women with endometriosis (n = 18) or benign gynecological disease (n=19).

INTERVENTION(S)

Eutopic ESCs were cultured under normoxia (20% O2) or hypoxia (6.5% O2), and migration and invasion capacity assayed, with pathway-focused polymerase chain reaction (PCR) array and ELISAs performed. CD26/dipeptidyl peptidase IV (DPPIV) expression was determined by flow cytometric analysis and enzymatic activity assay. The ESCs supplemented with Diprotin A (CD26 inhibitor), stromal cell-derived factor-1α, or AMD3100 (C-X-C motif receptor 4; CXCR4 blocker) were assayed for their migratory potential.

MAIN OUTCOME MEASURE(S)

Endometrial stromal cell migration and invasion under hypoxia.

RESULT(S)

Endometriotic ESCs showed significantly higher migration and invasion through collagen gels under hypoxia compared with nonendometriotic ESCs. The PCR array revealed down-regulation of the migration inhibitor CD26/DPPIV and up-regulation of angiogenic factors (vascular endothelial growth factor A, C-X-C motif Ligand 6; CXCL6) in endometriotic ESCs under hypoxia. The CD26/DPPIV surface expression and activity as well as angiogenic protein secretions suggested that the molecular mechanisms underlying aberrant migratory and angiogenic behavior in endometriotic ESCs. A combinatorial treatment with diprotin A and stromal cell-derived factor-1α effectively enhanced migration and invasion preferentially in endometriotic ESCs cultured hypoxically.

CONCLUSION(S)

Loss of CD26/DPPIV under hypoxia and the subsequent increase in migratory and angiogenic factors may favor conditions for lesion development in endometriosis.

Combined blockade of angiotensin II type 1 receptor and activation of peroxisome proliferator-activated receptor-γ by telmisartan effectively inhibits vascularization and growth of murine endometriosis-like lesions

STUDY QUESTION

Is telmisartan effective in the treatment of endometriosis?

SUMMARY ANSWER

Combined blockade of angiotensin II type 1 receptor (AT1R) and activation of peroxisome proliferator-activated receptor (PPAR)-γ by telmisartan inhibits vascularization and growth of murine endometriosis-like lesions.

WHAT IS KNOWN ALREADY

AT1R and PPAR-γ are involved in the regulation of inflammation, proliferation and angiogenesis. These processes are also crucial for the pathogenesis of endometriosis and both receptors are expressed in endometrial tissue. Telmisartan is a partial agonist of PPAR-γ, which additionally blocks AT1R.

STUDY DESIGN, SIZE, DURATION

This was a randomized study in the mouse dorsal skinfold chamber and peritoneal model of endometriosis. Endometriosis-like lesions were induced in dorsal skinfold chambers of 21 female C57BL/6 mice, and in the peritoneal cavity of 15 additional animals, which were daily treated with an i.p. injection of pioglitazone (10 mg/kg, n = 12), telmisartan (10 mg/kg, n = 12) or vehicle (5% dimethyl sulfoxide (DMSO), n = 12) throughout an observation period of 14 and 28 days, respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The anti-angiogenic actions of pioglitazone, a full PPAR-γ agonist, and telmisartan were firstly assessed in vitro by an aortic ring assay. Endometriosis-like lesions were induced in the dorsal skinfold chamber or peritoneal cavity and the effects of telmisartan and pioglitazone on their vascularization, immune cell content and growth were studied by intravital fluorescence microscopy, high-resolution ultrasound imaging as well as histological, immunohistochemical and immunofluorescent analyses. Additional quantitative real-time polymerase chain reaction (qRT-PCR) arrays served for gene expression profiling of the lesions. To limit the role of chance, the experiments were conducted under standardized laboratory conditions with appropriate vehicle-treated controls. Statistical significance was accepted for a value of P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

Telmisartan inhibited vascular sprout formation of aortic rings more effectively than pioglitazone. Accordingly, endometriosis-like lesions in dorsal skinfold chambers of telmisartan-treated animals exhibited a markedly lower functional microvessel density and blood perfusion. High-resolution ultrasound analyses of peritoneal endometriosis-like lesions revealed that the compound inhibited the stromal tissue growth, resulting in a significantly reduced final lesion volume. In contrast, the development of cysts did not differ between the groups. Moreover, telmisartan induced an up-regulation of PPAR-γ and a down-regulation of AT1R proteins in endometriosis-like lesions, which was associated with a decreased density of CD31-positive microvessels, a reduced immune cell content and a lower number of Ki67-positive proliferating cells. qRT-PCR arrays further demonstrated an inhibitory action of telmisartan on the expression of several angiogenic and inflammatory genes.

LIMITATIONS, REASONS FOR CAUTION

Endometriosis-like lesions were induced by syngeneic tissue transplantation into recipient mice without the use of pathological endometriotic tissue of human nature. Therefore, the results obtained in this study may not fully relate to human patients with endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrates that telmisartan inhibits vascularization, immune cell content and growth of endometriosis-like lesions. Accordingly, the combined blockade of AT1R and activation of PPAR-γ represents a promising new concept in the development of novel compounds for the treatment of endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

There was no specific funding of this study. The authors have no conflicts of interest to declare.

Regression of experimentally induced endometriosis with a new selective cyclooxygenase-2 enzyme inhibitor

BACKGROUND

Cyclooxygenase-2 (COX-2) levels increase in women with endometriosis. COX-2, via increasing prostaglandin E2, contributes to an increase in vascular endothelial growth factor. In this way, COX-2 may contribute to the progression and continuity of endometriosis. We investigated the effect of dexketoprofen trometamol, a new selective COX-2 enzyme inhibitor, on experimentally induced endometriotic cysts.

METHODS

Experimental endometriotic cysts were created in 60 adult female Wistar albino rats. The rats were randomized to 2 equal groups, a control (group Con) and a dexketoprofen (group Dex) group. Six weeks later, cyst volumes were measured as in vivo (volume 1). Following volume 1 measurement, for 4 weeks group Con received 0.1 ml distilled water; group Dex received 0.375 mg dexketoprofen trometamol/0.1 ml distilled water, intramuscularly, twice a day. At the end of administration, the cyst volumes were remeasured (volume 2), and the cysts totally excised and weighed. Glandular (GT) and stromal tissues (ST) and natural killer (NK) cell contents in the cyst wall were scored.

RESULTS

NK cell content and volume 1 were not different between the 2 groups. Volume 2, cyst weight, and GT and ST contents in group Dex were significantly lower than those in group Con.

CONCLUSION

Dexketoprofen trometamol significantly reduced the development of experimentally induced endometriotic cysts both macroscopically and microscopically.

The role of angiogenic factors in fibroid pathogenesis: potential implications for future therapy

BACKGROUND

It is well established that tumors are dependent on angiogenesis for their growth and survival. Although uterine fibroids are known to be benign tumors with reduced vascularization, recent work demonstrates that the vasculature of fibroids is grossly and microscopically abnormal. Accumulating evidence suggests that angiogenic growth factor dysregulation may be implicated in these vascular and other features of fibroid pathophysiology.

METHODS

Literature searches were performed in PubMed and Google Scholar for articles with content related to angiogenic growth factors and myometrium/leiomyoma. The findings are hereby reviewed and discussed.

RESULTS

Multiple growth factors involved in angiogenesis are differentially expressed in leiomyoma compared with myometrium. These include epidermal growth factor (EGF), heparin-binding-EGF, vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor-β and adrenomedullin. An important paradox is that although leiomyoma tissues are hypoxic, leiomyoma feature down-regulation of key molecular regulators of the hypoxia response. Furthermore, the hypoxic milieu of leiomyoma may contribute to fibroid development and growth. Notably, common treatments for fibroids such as GnRH agonists and uterine artery embolization (UAE) are shown to work at least partly via anti-angiogenic mechanisms.

CONCLUSIONS

Angiogenic growth factors play an important role in mechanisms of fibroid pathophysiology, including abnormal vasculature and fibroid growth and survival. Moreover, the fibroid's abnormal vasculature together with its aberrant hypoxic and angiogenic response may make it especially vulnerable to disruption of its vascular supply, a feature which could be exploited for treatment. Further experimental studies are required in order to gain a better understanding of the growth factors that are involved in normal and pathological myometrial angiogenesis, and to assess the potential of anti-angiogenic treatment strategies for uterine fibroids.

Identification of multiple and distinct defects in prostaglandin biosynthetic pathways in eutopic and ectopic endometrium of women with endometriosis

OBJECTIVE

To investigate prostaglandin (PG) biosynthesis and catabolism pathways in eutopic and ectopic endometrium of women with endometriosis.

DESIGN

Retrospective study.

SETTING

Human reproduction research laboratory.

PATIENT(S)

Forty-five women with endometriosis and 29 normal controls.

INTERVENTION(S)

Endometrial and endometriotic tissue samples were obtained during laparoscopic surgery.

MAIN OUTCOME MEASURE(S)

Cyclo-oxygenases (Coxs 1 and 2), PGE2 synthases (microsomal [m] PGES 1 and 2 and cytosolic [c] PGES), PGF2α synthases (aldoketoreductase [AKR]-1C3 and AKR-1B1), and the PG catabolic enzyme 15-hydroxyprostaglandin dehydrogenase messenger RNA expression by quantitative real-time polymerase chain reaction and protein localization by immunohistochemistry.

RESULT(S)

This study showed a marked increase in the key PG biosynthesis enzymes Cox-2, mPGES-1, mPGES-2, cPGES, and AKR-1C3 in ectopic endometrial tissue of women with endometriosis, particularly in the earliest and most active stages of the disease, without a noticeable change in the expression of the PG catabolic enzyme 15-hydroxyprostaglandin dehydrogenase. Meanwhile, the significant increase in rate-limiting Cox-2 expression upstream was correlated downstream by a significant stage- and cycle phase-dependent decrease in the terminal specific synthase mPGES-2, thereby revealing the presence of counter-regulatory mechanisms, which operate in the eutopic endometrium of women with endometrium but seem to be lacking in the ectopic implantation sites.

CONCLUSION(S)

This study reveals for the first time multiple defects in PG biosynthesis pathways, which differ between eutopic intrauterine and ectopic endometrial tissues and may, owing to the wide spectrum of PG properties, contribute to the initial steps of endometrial tissue growth and development and have an important role to play in the pathogenesis and symptoms of this disease.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits adhesion of human endometriotic epithelial and stromal cells through suppression of integrin-mediated mechanisms

Endometriosis is a chronic gynecological disease of reproductive age women characterized by the presence of functional endometrial tissues outside the uterine cavity. Interactions between the endometriotic cells and the peritoneal extracellular matrix proteins (ECM) are crucial mechanisms that allow adhesion of the endometriotic cells into peritoneal mesothelia. Prostaglandin E2 (PGE2) plays an important role in the pathogenesis of endometriosis. In previous studies, we have reported that selective inhibition of PGE2 receptors PTGER2 and PTGER4 decreases survival and invasion of human endometriotic epithelial and stromal cells through multiple mechanisms. Results of the present study indicates that selective inhibition of PTGER2- and PTGER4-mediated PGE2 signaling 1) decreases the expression and/or activity of specific integrin receptor subunits Itgb1 (beta1) and Itgb3 (beta3) but not Itgb5 (beta5), Itga1 (alpha1), Itga2 (alpha2), Itga5 (alpha5), and Itgav (alphav); 2) decreases integrin-signaling components focal adhesion kinase or protein kinase 2 (PTK2) and talin proteins; 3) inhibits interactions between Itgb1/Itgb3 subunits, PTK2, and talin and PTGER2/PTGER4 proteins through beta-arrestin-1 and Src kinase protein complex in human endometriotic epithelial cells 12Z and stromal cells 22B; and 4) decreases adhesion of 12Z and 22B cells to ECM collagen I, collagen IV, fibronectin, and vitronectin in a substrate-specific manner. These novel findings provide an important molecular framework for further evaluation of selective inhibition of PTGER2 and PTGER4 as potential nonsteroidal therapy to expand the spectrum of currently available treatment options for endometriosis in child-bearing age women.

Anastrozole and celecoxib for endometriosis treatment, good to keep them apart?

Endometriosis is a benign gynecological disease. Cyclooxygenase-2 (COX-2) and aromatase proteins have been shown to be overexpressed in eutopic endometrium from women suffering from this disease compared to disease-free women. Furthermore, inhibition of these molecules individually was demonstrated to have antiproliferative and proapoptotic effects both in vitro and in vivo in several models. In this study, the effect of combining celecoxib, a selective COX-2 inhibitor, and anastrozole, an aromatase inhibitor, on the implantation and growth of endometriotic like lesions in a murine model of endometriosis was evaluated. Endometriosis was surgically induced in female BALB/c mice. After 28 days of treatment with celecoxib, anastrozole, or their combination, animals were killed and lesions were counted, measured, excised, and fixed. Immunohistochemistry for proliferating cell nuclear antigen and CD34 was performed for assessment of cell proliferation and vascularization. TUNEL technique was performed for apoptosis evaluation. Celecoxib was the only treatment to significantly reduce the number of lesions established per mouse, their size and vascularized area. In addition, cell proliferation was significantly diminished and apoptosis was significantly enhanced by both individual treatments. When the therapies were combined, they reversed their effects. These results confirm that celecoxib and anastrozole separately decrease endometriotic growth, but when combined they might have antagonizing effects.

Suppression of annexin A2 by prostaglandin E₂ impairs phagocytic ability of peritoneal macrophages in women with endometriosis

STUDY QUESTION

Is annexin A2 involved in the reduced phagocytic ability of macrophages in endometriosis?

SUMMARY ANSWER

Data from women with endometriosis and a murine model of the disease show that expression of annexin A2 in peritoneal macrophages is inhibited by prostaglandin E2 (PGE2) and this impairs the phagocytic ability of macrophages.

WHAT IS ALREADY KNOWN

Endometriosis is a chronic inflammatory disease that recruits many immune cells, especially macrophages, to the peritoneal cavity. The phagocytic ability of peritoneal macrophages isolated from women with endometriosis is reduced.

STUDY DESIGN, SIZE, DURATION

A laboratory study. Thirty-five patients (20 with and 15 without endometriosis) of reproductive age with normal menstrual cycles were recruited.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Peritoneal macrophages isolated from women with or without endometriosis were cultured and treated with vehicle, PGE2 and different EP receptor agonists, and the expression of annexin A2 was quantified by RT-PCR and western blotting. Annexin A2 was knocked down (by small interfering RNA) in normal macrophages or overexpressed (by treatment with recombinant protein) in endometriotic macrophages and their phagocytic ability was measured by flow cytometry. Peritoneal macrophages were isolated from a mouse model of endometriosis and treated with PGE2 or cyclo-oxygenase (COX) inhibitors, and annexin A2 mRNA was quantified.

MAIN RESULTS AND THE ROLE OF CHANCE

Levels of annexin A2 were markedly reduced in peritoneal macrophages from women with endometriosis versus controls (mRNA: P < 0.01). The level of annexin A2 mRNA in the macrophages was reduced by PGE2 (P < 0.01/P < 0.05 in women without/with endometriosis versus control) via the EP2/EP4 receptor-dependent signaling pathway. Treatment with PGE2 or knockdown of annexin A2 inhibited the phagocytic ability of macrophages (P < 0.05 versus control), while treatment with annexin A2 recombinant protein enhanced phagocytosis. Autologous transplantation animal studies further confirmed that levels of annexin A2 in peritoneal macrophages were markedly reduced in mice treated with PGE2 (P < 0.01 versus control). In contrast, treatment with COX inhibitors to inhibit PGE2 production enhanced annexin A2 expression in peritoneal macrophages (P < 0.05 versus control).

LIMITATIONS, REASONS FOR CAUTION

We have provided no direct demonstration that phagocytic activity is indeed decreased in peritoneal cells from patients with endometriosis or that their endometriotic fluid contains increased amounts of PGE2 when compared with control subjects.

WIDER IMPLICATIONS OF THE FINDINGS

Inhibiting PGE2 signaling, in order to restore or enhance the phagocytic capability of macrophages, may represent a new direction of thinking in developing novel strategies against endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from National Science Council of Taiwan, Republic of China (NSC97-2314-B-006-020-MY3) to M.-H.W. and (NSC98-2320-B-006-026-MY3) to S.-J.T., and grants from the Chang Gung Memorial Hospital, Taiwan, Republic of China (CMRPG891432 and CMRPG8A0531) to P.-C.C. None of the authors have any conflicts of interest.

Techniques for visualization of cell-cell contact at the fetal-maternal interface

Historically, several in vitro/ex vivo microscopy imaging techniques have been used to study cellular interactions within the uterus and the placenta. As these experimental methods have revealed compelling facts about the biologic phenomena of cell-cell contacts in these organs, they cannot be used to study complex dynamic behavior of living cells inside their physiologic environment. For this, recent advances in intravital imaging techniques, together with two-photon microscopy, offer an exciting opportunity to study such dynamic immunologic processes at the cellular level in the complex uterine and placental tissues. In this article, we review experimental imaging techniques that have been used for studying the uterus and placenta. In particular, we describe the advantages of intravital techniques and discuss novel procedures that can be used in reproductive immunology. We also describe several technical details involved in image sequence post-processing required to extract useful data. Finally, we conclude by discussing how the reproductive immunology field may benefit from the broad use of these intravital techniques.

DNA hypomethylation of the COX-2 gene promoter is associated with up-regulation of its mRNA expression in eutopic endometrium of endometriosis

Background

Accumulated evidence reveals that cyclooxygenase-2 (COX-2) was overexpressed in eutopic endometrium of endometriosis, which may play a critical role in the pathogenesis of endometriosis. However, few studies have been performed to explore the molecular mechanisms underlying the abnormal high expression of COX-2 in endometriosis. Considering the fact that a number of recent studies have shown DNA methylation affecting some genes in endometriosis, the present study was therefore aimed to determine whether the observed high expression COX-2 in endometriosis is caused by the hypomethylation of CpG island within the promoter of this gene.

Methods

The endometrial tissues were collected from 60 women with endometriosis (endometriosis group) and 20 women without endometriosis (control group). The methylation status of COX-2 was examined by methylation specific PCR. Quantitative real-time RT-PCR was performed to measure COX-2 mRNA level in endometrial tissues.

Results

The frequency of promoter hypermethylation of COX-2 was lower in eutopic endometrium of the endometriosis group (41.7%) than that in the control group (75.0%), P < 0.05. COX-2 mRNA level in the eutopic endometrium of the endometriosis group was 2.61-fold higher than that in the control group (P < 0.01). COX-2 mRNA level in unmethylated endometrium of the endometriosis group or the control group was 2.39-fold and 2.66-fold, respectively, higher than that in the methylated endometrium of the same group (P < 0.01).

Conclusions

The hypomethylation within the promoter of COX-2 may be responsible for the elevated gene expression in eutopic endometrium of endometriosis.

Pyrrolidine dithiocarbamate attenuates nuclear factor-ĸB activation, cyclooxygenase-2 expression and prostaglandin E2 production in human endometriotic epithelial cells

BACKGROUND

The nuclear factor-κB (NF-κB) pathway activates many of the target genes that are critical to the initiation and establishment of endometriosis. We sought to examine the potential application of pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, in the treatment of endometriosis.

METHODS

The phosphorylation of IκB, expression of nuclear p65 protein and NF-κB DNA binding in endometriotic epithelial cells (EECs), endometriotic eutopic epithelial cells (EuECs) and normal epithelial cells (NECs) were detected by Western blot analysis and electrophoretic mobility shift assay. Cyclooxgenase-2 (COX-2) gene and protein expressions in EECs were measured by RT-PCR and Western blot analysis. Prostaglandin E(2) (PGE(2)) production of EECs was measured by ELISA.

RESULTS

PDTC in the absence or presence of tumor necrosing factor-α (TNF-α) showed stronger inhibitory effects on IκB phosphorylation, expression of nuclear p65 protein and NF-κB DNA-binding activity in EECs than in EuECs or NECs. Pretreatment of EECs with PDTC resulted in a dose-dependent reduction in the TNF-α-induced expressions of COX-2 at gene and protein levels, as well as a reduction of PGE(2) synthesis.

CONCLUSION

PDTC may represent a novel therapeutic strategy for treatment of endometriosis.

In vitro and in vivo evaluation of the anti-angiogenic actions of 4-hydroxybenzyl alcohol

BACKGROUND AND PURPOSE

4-Hydroxybenzyl alcohol (HBA) is a phenolic plant compound, which has been shown to influence many cellular mechanisms. In the present study, we analysed in vitro and in vivo the anti-angiogenic actions of this pleiotropic agent.

EXPERIMENTAL APPROACH

Migration and protein expression of HBA- and vehicle-treated endothelial-like eEND2 cells was assessed by cell migration assay and Western blot analyses. HBA action on vascular sprouting was analysed in an aortic ring assay. In vivo anti-angiogenic actions of HBA were studied in the dorsal skinfold chamber model of endometriosis in mice.

KEY RESULTS

Western blot analyses demonstrated that HBA inhibited proliferation of eEND2 cells, as indicated by down-regulation of proliferating cell nuclear antigen expression, and reduced expression of vascular endothelial growth factor and matrix metalloproteinase 9. HBA suppressed the migration of eEND2 cells, accompanied by inhibition of actin filament reorganization, revealed by fluorescence staining of the cytoskeleton. In addition, HBA reduced vascular sprouting in the aortic ring assay. Finally, we found, in the dorsal skinfold chamber model in vivo using intravital fluorescence microscopy, that HBA inhibited the vascularization of developing endometriotic lesions, as indicated by a decreased functional capillary density of lesions in HBA-treated mice and a reduced lesion size, compared with control animals.

CONCLUSIONS AND IMPLICATIONS

HBA targets several angiogenic mechanisms and therefore represents a promising anti-angiogenic agent for the treatment of angiogenic diseases, such as endometriosis.