PGE2 and PGF2 alpha release by human peritoneal macrophages in endometriosis

Endometriosis and Systemic Lupus Erythematosus: Systematic Review and Meta-analysis

Endometriosis is a chronic gynaecological condition characterized by inflammatory and immune abnormalities. Likewise, these dysfunctions are important hallmarks of systemic lupus erythematosus (SLE), a condition that also has a high prevalence among women in reproductive age. Therefore, we conducted a systematic review and meta-analysis to investigate the association between endometriosis and SLE. We searched Medline and Web of Science for articles published from database inception to March 1, 2021. Random-effects meta-analysis was performed to provide a pooled risk ratio (RR). Individual study quality was evaluated following the National Heart, Lung, and Blood Institute Quality Assessment Tools (NHLBI QAT). From the 225 articles identified through our search, five studies-assessing 152,355 women-were included. Included studies presented an overall poor or fair quality rating. We observed a significant association between endometriosis and SLE (RR = 2.47, 95% confidence interval: 1.33-4.59, P < 0.004, I2 = 54%). Sensitivity analyses stratifying articles by study design demonstrated that the association was significant in cross-sectional and case-control studies (RR = 5.07, 95% confidence interval: 1.42-18.11, P < 0.012), as well as in cohort studies (RR = 2.07, 95% confidence interval: 1.02-4.20, P < 0.044). In spite of the limited quality of included studies, our results suggest the existence of an association between endometriosis and SLE. These findings can aid medical assessment of patients with endometriosis, as well as provide further insights to better understand this gynaecological disorder.

Dysmenorrhea in adolescents

Studies show that between 41% and 91.5% of young women, school-aged and university-aged, are affected by dysmenorrhea. Primary dysmenorrhea, which is caused by the production of prostaglandins, is defined as cramping pain in the lower abdomen and/or pelvis occurring just before or during menstruation, in the absence of other diseases such as endometriosis, and typically lasting 1-3 days and with a negative physical examination. Secondary dysmenorrhea presents with similar signs and symptoms but is a result of underlying pelvic pathology, for example endometriosis or uterine fibroids. Dysmenorrhea most typically presents as abdominal cramping; however, it can also present with headaches, nausea, vomiting or other generalized symptoms. The diagnosis is mainly clinical, but other tests such as a pelvic examination, a pregnancy test and STI screening may be helpful in ruling out other sources of pain. Although the mainstay of treatment for dysmenorrhea is NSAIDs and hormonal therapy, lifestyle changes and complementary/alternative medicine can also be helpful approaches. Lifestyle changes include aerobic exercise and stretching, while complementary alternative medicine include peppermint, cinnamon, ginger and other herbs and supplements. Finally, endometriosis must be considered as a potential cause for secondary dysmenorrhea and would warrant a prompt referral to gynecology.

The effect of acetylsalicylic acid on pain and recurrence of endometriosis after surgery: A randomized controlled trial

Background:

Reactive oxygen species (ROS) might increase growth and adhesion of endometrial cells in the peritoneal cavity, and lead to endometriosis. In this study the we evaluate the effect of an antioxidant, acetylsalicylic acid (aspirin), to determine whether aspirin administration to patients with endometriosis would affect pelvic pain and disease recurrence.

Material and methods:

This randomized controlled trial was conducted from March 2018 to March 2020 on women, 19 to 40 years of age, who were diagnosed with endometriosis after undergoing laparoscopic surgery. Study participants were randomly assigned to one of two groups, Oral contraceptive pills (OCP) and placebo or OCP and aspirin, which were administered daily for 6 months. Pelvic pain, dysmenorrhea, mass size, and menstrual bleeding were evaluated at 3 and 6 months.

Results:

There were 38 patients in the aspirin group and 49 participants in the placebo group. The mean dysmenorrhea Visual analog scale (VAS) score after 3 months was 2.24 in the aspirin group and 3.61 in the placebo group. After 6 months, the dysmenorrhea VAS scores were 0.68 (aspirin group) and 2.69 (placebo group) ( p = 0.005 and p = 0.00, respectively). Dyspareunia and pelvic pain showed significant reductions ( p = 0.00). Six patients in the control group and four patients in the aspirin group experienced lesion recurrence ( p = 0.45).

Conclusion:

The results suggest that aspirin, as an antioxidant, could effectively reduce pain in women with endometriosis. However, additional studies that enroll larger numbers of participants and long-term follow up will enable better evaluation of recurrence.

Endometriosis Is Associated with Adverse Pregnancy Outcomes: a National Population-Based Study

Pregnancy and neonatal outcomes in women diagnosed with endometriosis were investigated using data collected from the Korea National Health Insurance Claims Database and the National Health Screening Program for Infants and Children. A total of 3,778,561 women who gave birth between 2007 and 2015 were identified, and 1,938,424 primiparous women and their newborns were included in this study. Women with a diagnosis of endometriosis had a significantly higher incidence of multiple pregnancy, cesarean section, breech presentation, postpartum hemorrhage, placental abruption, placenta previa, and stillbirth than women without endometriosis (P < 0.0001). The rates of preterm birth and low birth weight were also increased in women with endometriosis (P < 0.0001). After adjusting for age, the estimated risks of these outcomes remained significant. Women previously diagnosed with endometriosis have an increased risk of adverse pregnancy and neonatal outcomes. Particular attention and information regarding these conditions should be provided to women with endometriosis during the preconception or antenatal periods.

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.

Endometrial Intracrinology: Oestrogens, Androgens and Endometrial Disorders

Peripheral tissue metabolism of steroids (intracrinology) is now accepted as a key way in which tissues, such as the endometrium, can utilise inactive steroids present in the blood to respond to local physiological demands and 'fine-tune' the activation or inhibition of steroid hormone receptor-dependent processes. Expression of enzymes that play a critical role in the activation and inactivation of bioactive oestrogens (E1, E2) and androgens (A4, T, DHT), as well as expression of steroid hormone receptors, has been detected in endometrial tissues and cells recovered during the menstrual cycle. There is robust evidence that increased expression of aromatase is important for creating a local microenvironment that can support a pregnancy. Measurement of intra-tissue concentrations of steroids using liquid chromatography⁻tandem mass spectrometry has been important in advancing our understanding of a role for androgens in the endometrium, acting both as active ligands for the androgen receptor and as substrates for oestrogen biosynthesis. The emergence of intracrinology, associated with disordered expression of key enzymes such as aromatase, in the aetiology of common women's health disorders such as endometriosis and endometrial cancer has prompted renewed interest in the development of drugs targeting these pathways, opening up new opportunities for targeted therapies and precision medicine.

Novel dietary supplement association reduces symptoms in endometriosis patients

Endometriosis is characterized by disabling symptoms that afflict young women with severe physical discomfort, difficulty in relationship life, and infertility; however, the currently available therapeutic strategies are unsatisfactory. Goal of this research was to identify a new combination of natural active ingredients that, administered as dietary supplements, could have the effect of reducing inflammatory response in endometriosis patients, decreasing the symptoms the disease produces and its harmful effects on affected organs. A cohort of endometriosis patient was treated for 3 months with a composition including quercitin, curcumin, parthenium, nicotinamide, 5-methyltetrahydrofolate, and omega 3/6. Using a VAS scale, we demonstrated a significant reduction of the symptoms in endometriosis patients treated with the dietary composition respect to the controls. Moreover, we demonstrated also a significant reduction in the serum levels of PGE2 and CA-125. Further study are required to compare the effect of this combination of molecules with standard therapies and to evaluate if the use of these dietary supplements in combination with standard therapies may lead to the improvement of the regular medical treatment for endometriosis.

Lipopolysaccharide promotes the development of murine endometriosis-like lesions via the nuclear factor-kappa B pathway

PROBLEM

Is lipopolysaccharide (LPS) involved in the development of endometriosis?

METHOD OF STUDY

BALB/c mice (n=69) were used for the murine endometriosis model. Mice with surgically induced endometriosis were injected with LPS intraperitoneally. After 4 weeks of LPS injections with or without the nuclear factor-kappa B (NF-κB) inhibitor, the extent of endometriosis-like lesions was evaluated. Expression of inflammatory factors in the implants was evaluated using real-time RT-PCR. Cell proliferation, angiogenic activity, inflammation, and NF-κB phosphorylation were assessed by immunohistochemical staining.

RESULTS

Lipopolysaccharide increased total number, size, and mRNA expression of Ptgs-2, Vegf, Ccl-2, and Il-6 in endometriosis-like lesions. LPS also increased the percentage of Ki67-positive cells and enhanced the intensity and rate of positive cells of CD3, F4/80, and PECAM. Intense expression of phospho-NF-κB p65 after LPS administration was observed. Treatment with the NF-kB inhibitor negated these LPS-induced effects.

CONCLUSION

LPS-induced pelvic inflammation status enhanced the development of murine endometriosis-like lesions via NF-κB pathway.

Prostaglandin levels, vaginal innervation, and cyst innervation as peripheral contributors to endometriosis-associated vaginal hyperalgesia in rodents

Endometriosis is a painful condition characterized by growth of endometrial cysts outside the uterus. Here, we tested the hypothesis that peripheral innervation and prostaglandin levels contribute to endometriosis-associated pain. Female Sprague-Dawley rats (n = 16) were surgically instrumented by transplanting uterine tissue onto mesenteric arteries within the peritoneal cavity to create a model of endometriosis which forms extra-uterine endometrial cysts and vaginal hyperalgesia. Our results describe a significant positive correlation between endometriosis-induced vaginal hyperalgesia and cyst innervation density (sensory, r = 0.70, p = 0.003; sympathetic, r = 0.55, p = 0.03), vaginal canal sympathetic innervation density (r = 0.80, p = 0.003), and peritoneal fluid levels of the prostaglandins PGE2 (r = 0.65, p = 0.01) and PGF2α (r = 0.63, p = 0.02). These results support the involvement of cyst innervation and prostaglandins in endometriosis-associated pain. We also describe how sympathetic innervation density of the vaginal canal is an important predictor of vaginal hyperalgesia.

Regulation of Matrix Metalloproteinase-2 Activity by COX-2-PGE2-pAKT Axis Promotes Angiogenesis in Endometriosis

Endometriosis is characterized by the ectopic development of the endometrium which relies on angiogenesis. Although studies have identified the involvement of different matrix metalloproteinases (MMPs) in endometriosis, no study has yet investigated the role of MMP-2 in endometriosis-associated angiogenesis. The present study aims to understand the regulation of MMP-2 activity in endothelial cells and on angiogenesis during progression of ovarian endometriosis. Histological and biochemical data showed increased expressions of vascular endothelial growth factor (VEGF), VEGF receptor-2, cycloxygenase (COX)-2, von Willebrand factor along with angiogenesis during endometriosis progression. Women with endometriosis showed decreased MMP-2 activity in eutopic endometrium as compared to women without endometriosis. However, ectopic ovarian endometrioma showed significantly elevated MMP-2 activity with disease severity. In addition, increased MT1MMP and decreased tissue inhibitors of metalloproteinases (TIMP)-2 expressions were found in the late stages of endometriosis indicating more MMP-2 activation with disease progression. In vitro study using human endothelial cells showed that prostaglandin E2 (PGE2) significantly increased MMP-2 activity as well as tube formation. Inhibition of COX-2 and/or phosphorylated AKT suppressed MMP-2 activity and endothelial tube formation suggesting involvement of PGE2 in regulation of MMP-2 activity during angiogenesis. Moreover, specific inhibition of MMP-2 by chemical inhibitor significantly reduced cellular migration, invasion and tube formation. In ovo assay showed decreased angiogenic branching upon MMP-2 inhibition. Furthermore, a significant reduction of lesion numbers was observed upon inhibition of MMP-2 and COX-2 in mouse model of endometriosis. In conclusion, our study establishes the involvement of MMP-2 activity via COX-2-PGE2-pAKT axis in promoting angiogenesis during endometriosis progression.

Limited value of pro-inflammatory oxylipins and cytokines as circulating biomarkers in endometriosis - a targeted 'omics study

Endometriosis is a common, complex gynecologic disorder characterized by the presence of endometrial-like tissues at extrauterine sites. Elevation in protein and lipid mediators of inflammation including oxylipins and cytokines within the peritoneum characterize the inflamed pelvic region and may contribute to the survival and growth of displaced endometrial tissues. The presence of a clinically silent but molecularly detectable systemic inflammation in endometriosis has been proposed. Thus, we examined serum oxylipin and immunomodulatory protein levels in 103 women undergoing laparoscopy to evaluate systematically any involvement in systemic pathophysiological inflammation in endometriosis. Oxylipin levels were similar between women with and without endometriosis. Stratification by menstrual phase or severity did not offer any difference. Women with ovarian endometriosis had significantly lower 12-HETE relative to peritoneal endometriosis (−50.7%). Serum oxylipin levels were not associated with pre-operative pain symptoms. Changes to immunomodulatory proteins were minimal, with IL-12(p70), IL-13 and VEGF significantly lower in mild endometriotic women compared to non-endometriotic women (−39%, −54% and −76% respectively). Verification using C-reactive protein as a non-specific marker of inflammation further showed similar levels between groups. The implications of our work suggest pro-inflammatory mediators in the classes studied may have potentially limited value as circulating biomarkers for endometriosis, suggesting of potentially tenuous systemic inflammation in endometriosis.

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.

Induction of the neurokinin 1 receptor by TNFα in endometriotic tissue provides the potential for neurogenic control over endometriotic lesion growth

CONTEXT

Endometriosis is characterized by the growth of ectopic endometrial tissue. Nerve fibers are frequently associated with ectopic lesions, and neurogenic inflammation may play a role in endometriosis.

OBJECTIVE

The purpose of this study was to determine the presence of tachykinin receptors in endometriotic lesions and the role of TNFα on their expression.

DESIGN

This study was an assessment of matching eutopic and ectopic endometrial tissue and peritoneal fluid from patients with endometriosis and an in vitro analysis of primary endometrial cells.

SETTING

The setting was a university hospital.

PATIENTS

Participants were premenopausal women undergoing laparoscopy.

INTERVENTIONS

Endometriotic lesions were removed surgically.

MAIN OUTCOME MEASURES

Tachykinin mRNA (TACR1/2) and protein (neurokinin 1 receptor [NK1R]) expression in both eutopic and ectopic endometrial tissue from patients with endometriosis and the correlation to peritoneal fluid TNFα were measured. Primary endometrial epithelial and stromal cells were assessed in vitro to determine the induction of TACR1/2 and NK1R expression after TNFα treatment. Cell viability of endometrial stromal cells after substance P exposure was also assessed.

RESULTS

Expression of both TACR1 and TACR2 mRNA was significantly higher in the ectopic than in the eutopic tissue. Both TACR1 mRNA and NK1R protein expression was significantly correlated with peritoneal fluid TNFα, and in vitro studies confirmed that TNFα treatment induced both TACR1 mRNA and NK1R protein expression in endometrial stromal cells. In endometrial stromal cells, substance P treatment enhanced cell viability, which was inhibited by a specific NK1R antagonist.

CONCLUSIONS

NK1R expression is induced in ectopic endometrial tissue by peritoneal TNFα. Induction of NK1R expression may permit endometriotic lesion maintenance via exposure to substance P.

Augmented epithelial multidrug resistance-associated protein 4 expression in peritoneal endometriosis: regulation by lipoxin A(4)

OBJECTIVE

To compare the expression of the prostaglandin (PG) E(2) transporter multidrug resistance-associated protein 4 (MRP4) in eutopic and ectopic endometrial tissue from endometriosis patients with that of control subjects and to examine whether MRP4 is regulated by the antiinflammatory lipid lipoxin A(4) (LXA(4)) in endometriotic epithelial cells.

DESIGN

Molecular analysis in human samples and a cell line.

SETTING

Two university hospitals and a private clinic.

PATIENT(S)

A total of 59 endometriosis patients and 32 age- and body mass index-matched control subjects undergoing laparoscopy or hysterectomy.

INTERVENTION(S)

Normal, eutopic, and ectopic endometrial biopsies as well as peritoneal fluid were obtained during surgery performed during the proliferative phase of the menstrual cycle. 12Z endometriotic epithelial cells were used for in vitro mechanistic studies.

MAIN OUTCOME MEASURE(S)

Tissue MRP4 mRNA levels were quantified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and localization was analyzed with the use of immunohistochemistry. Cellular MRP4 mRNA and protein were quantified by qRT-PCR and Western blot, respectively. PGE(2) was measured in peritoneal fluid and cell supernatants using an enzyme immunoassay (EIA).

RESULT(S)

MRP4 was expressed in eutopic and ectopic endometrium, where it was overexpressed in peritoneal lesions and localized in the cytoplasm of glandular epithelial cells. LXA(4) attenuated MRP4 mRNA and protein levels in endometriotic epithelial cells in a dose-dependent manner, while not affecting the expression of enzymes involved in PGE(2) metabolism. Investigations employing receptor antagonists and small interfering RNA revealed that this occurred through estrogen receptor α. Accordingly, LXA(4) treatment inhibited extracellular PGE(2) release.

CONCLUSION(S)

We report for the first time that MRP4 is expressed in human endometrium, elevated in peritoneal endometriosis, and modulated by LXA(4) in endometriotic epithelial cells.

The importance of the macrophage within the human endometrium

The human endometrium is exposed to cyclical fluctuations of ovarian-derived sex steroids resulting in proliferation, differentiation (decidualization), and menstruation. An influx of leukocytes (up to 15% macrophages) occurs during the latter stages of the menstrual cycle, including menses. We believe the endometrial macrophage is likely to play an important role during the menstrual cycle, especially in the context of tissue degradation (menstruation), which requires regulated repair, regeneration, and phagocytic clearance of endometrial tissue debris to re-establish tissue integrity in preparation for fertility. The phenotype and regulation of the macrophage within the endometrium during the menstrual cycle and interactions with other cell types that constitute the endometrium are currently unknown and are important areas of study. Understanding the many roles of the endometrial macrophage is crucial to our body of knowledge concerning functionality of the endometrium as well as to our understanding of disorders of the menstrual cycle, which have major impacts on the health and well-being of women.

Endometriosis and headache

Headache and endometriosis show some similarities in their clinical and epidemiological features that are probably due to the influence of female sexual hormones on both disorders. Epidemiological studies indicate that they are comorbid disorders. However, the nature of the comorbidity is not known with certainty, but a likely explanation may be common susceptibility genes. Another possibility is that, because they both are related to pain, increased pain sensitivity induced by one of the disorders may lead to a higher likelihood of developing the other, possibly mediated by nitrogen oxide or prostaglandins. A common link to the widespread use of estroprogestins may seem less probable. For physicians dealing with women with either of these disorders, awareness of the comorbidity may be helpful in the treatment of the patient.

Aberrant expression of apoptosis-related molecules in endometriosis: a possible mechanism underlying the pathogenesis of endometriosis

Endometriosis, a disease affecting 3% to 10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue under the influence of estrogen. It is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a "death" signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of antiapoptotic factors and decreased expression of preapoptotic factors. Further investigations may elucidate the role of apoptosis-associated molecules in the pathogenesis of endometriosis. Medical treatment with apoptosis-inducing agents may be novel and promising therapeutic strategy for endometriosis.

Apigenin inhibits tumor necrosis factor α-induced cell proliferation and prostaglandin E2 synthesis by inactivating NFκB in endometriotic stromal cells

Apigenin suppressed tumor necrosis factor α-induced cell proliferation and prostaglandin E2 expression via the attenuation of nuclear factor κB pathway in endometriotic stromal cells in vitro. Apigenin reduced the mitogenic activity and inflammatory reaction in endometriotic stromal cells.

Inflammatory pathways in female reproductive health and disease

Inflammation involves alterations to vascular and immune cell function. It is well recognised that many physiological reproductive events such as ovulation, menstruation, implantation and onset of labour display hallmark signs of inflammation. These are orchestrated by specific molecular pathways involving a host of growth factors, cytokines, chemokines and lipid mediators. Resumption of normal reproductive function involves prompt and proper resolution of these inflammatory pathways. Recent literature confirms that resolution of inflammatory pathways involves specific biochemical events that are activated to re-establish homeostasis in the affected tissue. Moreover, initiation and maintenance of inflammatory pathways are the key components of many pathologies of the reproductive tract and elsewhere in the body. The onset of reproductive disorders or disease may be the result of exacerbated activation and maintenance of inflammatory pathways or their dysregulated resolution. This review will address the role of inflammatory events in normal reproductive function and its pathologies.

EP2 receptor mediated cAMP release is augmented by PGF 2 alpha activation of the FP receptor via the calcium-calmodulin pathway

Prostaglandins exert their effects on target cells by coupling to specific G protein-coupled receptors (GPCRs) that are often co-expressed in the same cells and use alternate and in some cases opposing intracellular signaling pathways. This study investigated the cross-talk that influences intracellular signaling and gene expression profiling in response to co-activation of the EP2 and FP prostanoid receptors in Ishikawa cells stably expressing both receptors (FPEP2 cells). In this study we show that in FPEP2 cells, PGF alone does not alter adenosine 3',5'-cyclic monophosphate (cAMP) production, but in combination with Butaprost enhances EP2 receptor mediated cAMP release compared to treatment with Butaprost alone. PGF-mediated potentiation of cAMP release was abolished by antagonism of the FP receptor, inhibition of phospholipase C (PLC) and inositol phosphate receptor (IP3R) whereas inhibition of protein kinase C (PKC) had no effect. Moreover, inhibition of calcium effectors using calmodulin antagonist (W7) or Ca(2+)/calmodulin-dependent kinase II (CaMK-II) inhibitor (KN-93) abolished PGF potentiation of Butaprost-mediated cAMP release. Using siRNA molecules targeted against the adenylyl cyclase 3 (AC3) isoform, we show that AC3 is responsible for the cross-talk between the FP and EP2 receptors. Using gene array studies we have identified a candidate gene, Spermidine/N1-acetyltransferase (SAT1), which is regulated by this cAMP mediated cross-talk. In conclusion, this study demonstrates that co-activation of the FP and EP2 receptors results in enhanced release of cAMP via FP receptor-G alpha(q)-Ca(2+)-calmodulin pathway by activating calcium sensitive AC3 isoform.

Lipopolysaccharide promoted proliferation and invasion of endometriotic stromal cells via induction of cyclooxygenase-2 expression

Lipopolysaccharide-enhanced cyclooxygenase 2 (COX-2) expression and prostaglandin E2 (PGE2) production were compared in endometriotic stromal cells (ESCs) and eutopic endometrial stromal cells. Lipopolysaccharide promotes the proliferation and invasion of ESCs via up-regulation of COX-2 and PGE2 expression, suggesting that pelvic inflammation may promote the progression of endometriosis.

Rich innervation of deep infiltrating endometriosis

BACKGROUND

Deep infiltrating endometriosis (DIE) is a specific type of endometriosis, which can be associated with more severe pelvic pain than other forms of endometriotic lesions. However, the mechanisms by which pain is generated are not well understood.

METHODS

DIE (n = 31) and peritoneal endometriotic (n = 40) lesions were sectioned and stained immunohistochemically with antibodies against protein gene product 9.5, neurofilament, nerve growth factor (NGF), NGF receptors tyrosine kinase receptor-A (Trk-A) and p75, substance P, calcitonin gene-related peptide, vesicular acetylcholine transporter, neuropeptide Y, vasoactive intestinal peptide and tyrosine hydroxylase to demonstrate myelinated, unmyelinated, sensory and autonomic nerve fibres.

RESULTS

There were significantly more nerve fibres in DIE (67.6 +/- 65.1/mm(2)) than in peritoneal endometriotic lesions (16.3 +/- 10.0/mm(2)) (P < 0.01). DIE was innervated abundantly by sensory Adelta, sensory C, cholinergic and adrenergic nerve fibres; NGF, Trk-A and p75 were strongly expressed in endometriotic glands and stroma of DIE.

CONCLUSIONS

The rich innervation of DIE may help to explain why patients with this type of lesion have severe pelvic pain.

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

Endometriosis is a debilitating disease characterized by the presence of functional endometrial glandular epithelium and stroma outside the uterine cavity that affects up to 20% of women of child-bearing age. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the biosynthesis of prostaglandin E(2) (PGE(2)), is highly expressed in endometriotic tissues and results in increased concentrations of peritoneal PGE(2) in women. In this study, we determined the expression of COX-2 protein in ectopic and eutopic endometria in humans and the role of COX-2 in endometriotic cell survival, migration, and invasion in humans. Our results indicate that COX-2 protein is abundantly expressed in ectopic endometria compared with eutopic endometria. Comparatively, expression of COX-2 protein is higher in eutopic endometria from women with endometriosis compared with women without endometriosis. Inhibition of COX-2 decreases survival, migration, and invasion of endometriotic cells that are associated with decreased production of PGE(2). Cell growth inhibitory effects of COX-2 inhibition/silencing are mediated through nuclear poly (ADP-ribose) polymerase-mediated apoptosis. Cell motility and invasion inhibitory effects of COX-2 inhibition/silencing are mediated through matrix metalloproteinase-2 and -9 activities. Interestingly, effects of COX-2 inhibition is more profound in endometriotic epithelial than in stromal cells. Furthermore, inhibition of COX-2 affects invasion rather than migration of endometriotic epithelial and stromal cells. It is the first evidence showing that inhibition of COX-2 decreases endometriotic epithelial and stromal cell survival, migration, and invasion in humans. Our results support the emerging concept that COX-2/PGE(2) promotes the pathophysiology and pathogenesis of endometriosis in humans.

Gene expression profiles and functional characterization of human immortalized endometriotic epithelial and stromal cells

OBJECTIVE

To determine whether immortalized endometriotic cells can be used as potential models to unravel pathophysiology/pathogenesis of endometriosis in humans.

DESIGN

In vitro study. Human immortalized endometriotic epithelial and stromal cells.

SETTING

College of Veterinary Medicine and Biomedical Sciences, Texas A&M University.

PATIENT(S)

Not applicable.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Gene expression pattern and prostaglandin E(2) production and activity of matrix metalloproteinase 2 and matrix metalloproteinase 9.

RESULT(S)

Several genes associated with estrogen and progesterone biosynthesis and signaling, cell cycle regulation, extracellular matrix degradation, angiogenesis, cell growth and survival, cytokine production, and prostaglandin E(2) biosynthesis, transport, and signaling were expressed in human immortalized endometriotic cells. These endometriotic epithelial and stromal cells exhibited migrating and invading potential, produced a high quantity of prostaglandin E(2), and showed higher matrix metalloproteinase 2 and matrix metalloproteinase 9 activity compared to normal endometrial, epithelial, and stromal cells.

CONCLUSION(S)

Human immortalized endometriotic epithelial and stromal cells could be used as ideal models to study the molecular and cellular aspects of endometriosis in humans.

Peroxisome proliferator-activated receptor-gamma agonist rosiglitazone reduces the size of experimental endometriosis in the rat model

BACKGROUND

The effect of rosiglitazone, an activator of peroxisome proliferator-activated receptor-gamma, on the growth of ectopic uterine tissue was assessed.

METHODS

Endometriosis was surgically induced in 28 rats by transplanting an autologous fragment of endometrial tissue onto the inner surface of the abdominal wall. Four weeks later, rats were randomly grouped and a second laparatomy was performed. The length, width, height and volume of the explants were measured. Rosiglitazone at 0.2 mg/kg/day was orally administered to one group, while vehicle treatment was given to the control group. Four weeks later, rats were sacrificed and ectopic uterine tissues were re-evaluated morphologically and histologically. Scoring system was used to evaluate the preservation of epithelia.

RESULTS

One rat in the study group and two rats in the control group died as a result of complications related to surgery. There was a significant difference in post-treatment length, width, height, and spherical volumes between control and rosiglitazone-treated groups. The epithelia were found to be preserved significantly better in the control group when compared with the rosiglitazone-treated group.

CONCLUSION

Rosiglitazone was found to cause regression of experimental endometriosis in rats.

Prostaglandin receptors are mediators of vascular function in endometrial pathologies

Prostaglandins are bioactive lipids produced from arachidonic acid by cyclooxygenase enzymes and specific terminal prostanoid synthase enzymes. Following biosynthesis, prostaglandins exert an autocrine/paracrine function by coupling to specific prostanoid G protein-coupled receptors to activate intracellular signaling and gene transcription. For many years prostaglandins have been recognised as key molecules in reproductive biology by regulating ovulation, endometrial physiology and proliferation of endometrial glands and menstruation. More recently a role for COX enzymes and prostaglandins has been ascertained in reproductive tract pathology, including dysmenorrhea, endometriosis, menorrhagia and cancer. Emerging evidence supports a role for COX enzymes, prostaglandins and prostaglandin receptor signaling pathways in a multitude of phenotypic changes in reproductive tissues including the promotion of angiogenesis and vascular function. Here we provide an overview of some of the findings from these studies with specific emphasis on the role of cyclooxygenase enzymes, prostaglandins and their receptors in benign and neoplastic pathologies of the human endometrium.

Prostanoid receptor EP1 and Cox-2 in injured human nerves and a rat model of nerve injury: a time-course study

Background

Recent studies show that inflammatory processes may contribute to neuropathic pain. Cyclooxygenase-2 (Cox-2) is an inducible enzyme responsible for production of prostanoids, which may sensitise sensory neurones via the EP1 receptor. We have recently reported that while macrophages infiltrate injured nerves within days of injury, they express increased Cox-2-immunoreactivity (Cox-2-IR) from 2 to 3 weeks after injury. We have now investigated the time course of EP1 and Cox-2 changes in injured human nerves and dorsal root ganglia (DRG), and the chronic constriction nerve injury (CCI) model in the rat.

Methods

Tissue sections were immunostained with specific antibodies to EP1, Cox-2, CD68 (human macrophage marker) or OX42 (rat microglial marker), and neurofilaments (NF), prior to image analysis, from the following: human brachial plexus nerves (21 to 196 days post-injury), painful neuromas (9 days to 12 years post-injury), avulsion injured DRG, control nerves and DRG, and rat CCI model tissues. EP1 and NF-immunoreactive nerve fibres were quantified by image analysis.

Results

EP1:NF ratio was significantly increased in human brachial plexus nerve fibres, both proximal and distal to injury, in comparison with uninjured nerves. Sensory neurones in injured human DRG showed a significant acute increase of EP1-IR intensity. While there was a rapid increase in EP1-fibres and CD-68 positive macrophages, Cox-2 increase was apparent later, but was persistent in human painful neuromas for years. A similar time-course of changes was found in the rat CCI model with the above markers, both in the injured nerves and ipsilateral dorsal spinal cord.

Conclusion

Different stages of infiltration and activation of macrophages may be observed in the peripheral and central nervous system following peripheral nerve injury. EP1 receptor level increase in sensory neurones, and macrophage infiltration, appears to precede increased Cox-2 expression by macrophages. However, other methods for detecting Cox-2 levels and activity are required. EP1 antagonists may show therapeutic effects in acute and chronic neuropathic pain, in addition to inflammatory pain.

Increased frequency of migraine among women with endometriosis

BACKGROUND

Our aim is to assess the prevalence and characteristics of headache in patients with endometriosis compared with women without this disease.

METHODS

One hundred and thirty-three women with histologically proven endometriosis and 166 controls were interviewed by a neurologist experienced in headache diagnosis; the headache disorders were classified according to the 1988 International Headache Society criteria.

RESULTS

The prevalence of migraine was significantly higher among women with endometriosis [n = 51, 38.3%; 95% confidence interval (CI) 30.1-47.2%] than in controls (n = 25, 15.1%; 95% CI 10.0-21.4%) (P < 0.001). Migraine with aura was observed in 18 women with endometriosis (13.5%) and in two controls (1.2%; P < 0.001). The age at migraine onset was significantly lower in women with endometriosis than in controls (16.4 versus 21.9 years; P = 0.001). No significant difference was observed in pain intensity and attack frequency between the two groups; a trend for women with endometriosis to have longer unmedicated attacks was observed. No significant correlation was observed between attack frequency, unmedicated headache duration, migraine intensity and the severity of endometriosis.

CONCLUSION

Migraine is more frequent in women with endometriosis than in controls, although its presence and characteristics are not related to the severity of endometriosis.

Nimesulide, a COX-2 inhibitor, does not reduce lesion size or number in a nude mouse model of endometriosis

BACKGROUND

Women with endometriosis have elevated levels of cyclooxygenase-2 (COX-2) in peritoneal macrophages and endometriotic tissue. Inhibition of COX-2 has been shown to reduce inflammation, angiogenesis and cellular proliferation. It may also downregulate aromatase activity in ectopic endometrial lesions. Ectopic endometrial establishment and growth are therefore likely to be suppressed in the presence of COX-2 inhibitors. We hypothesized that COX-2 inhibition would reduce the size and number of ectopic human endometrial lesions in a nude mouse model of endometriosis.

METHODS

The selective COX-2 inhibitor, nimesulide, was administered to estrogen-supplemented nude mice implanted with human endometrial tissue. Ten days after implantation, the number and size of ectopic endometrial lesions were evaluated and compared with lesions from a control group. Immunohistochemical assessment of vascular development and macrophage and myofibroblast infiltration in control and treated lesions was performed.

RESULTS

There was no difference in the number or size of ectopic endometrial lesions in control and nimesulide-treated nude mice. Nimesulide did not induce a visually identifiable difference in blood vessel development or macrophage or myofibroblast infiltration in nude mouse explants.

CONCLUSION

The hypothesized biological properties of COX-2 inhibition did not influence lesion number or size in the nude mouse model of endometriosis.

Macrophages are activated by 17beta-estradiol: possible permission role in endometriosis

On the basis of the common occurrence of high concentration of estrogen and activated macrophages in patients with endometriosis, we postulate that interaction between 17beta-estradiol and macrophage may be an important affair in endometriosis. So our study was focused on the effect of 17beta-estradiol on macrophage. First morphology of macrophages was examined with environmental scanning electron microscopy. Increased size, extension of more microvilli, expression of retraction fibers and elaboration of membrane ruffles were detected in 17beta-estradiol treated macrophages. Then Nitrate and nitrite level in the supernatant was measured by the method of Griess and iNOS expression was analyzed using immunohistochemical staining. It showed that 17beta-estradiol could induce NO release from peritoneal macrophages and expression of iNOS was increased. Also more TNF-alpha in supernatant that was measured by MTT via L929 cell was produced by macrophages under the inducing of 17beta-estradiol. Furthermore, [Ca2+]i, which was viewed by microscope in a laser scanning confocal unit, elevated 39.8% in peritoneal macrophages after 17beta-estradiol 100 nmol/L treated. The results above demonstrated that peritoneal macrophage had been activated in both morphology and cytokine line when interaction with 17beta-estradiol, which indicated that macrophage activated by 17beta-estradiol might play a permission role in development of endometriosis.

Regression of endometrial explants in rats treated with the cyclooxygenase-2 inhibitor rofecoxib

OBJECTIVE

To investigate the effects of cyclooxygenase-2 (COX-2) inhibitor rofecoxib on endometrial explants and on peritoneal vascular endothelial growth factor (VEGF) levels in the rat endometriosis model.

DESIGN

Prospective, placebo-controlled study.

SETTING

Laboratory at Dokuz Eylül University.

ANIMAL(S)

Twenty-six rats with experimentally induced endometriosis.

INTERVENTION(S)

Rats were treated for 3 weeks with oral rofecoxib (3 mg/kg per day; n = 9); single subcutaneous injection of depot leuprolide acetate (1 mg/kg; n = 9); or vehicle (control; n = 8).

MAIN OUTCOME MEASURE(S)

Change in explant area and histologic examination by semiquantitative analysis of endometriotic explants and measurement of peritoneal VEGF levels.

RESULT(S)

Three weeks of treatment with rofecoxib statistically significantly decreased the implant size (62.4%) compared with control (16.6%), and this effect was comparable with the decrease in leuprolide (64.3%). Histologic examination of the explants indicated mostly atrophy and regression in treatment groups, and semiquantitative analysis showed statistically significantly lower scores in rats treated with rofecoxib and leuprolide compared with controls. Both rofecoxib and leuprolide statistically significantly decreased VEGF levels compared with controls.

CONCLUSION(S)

Rofecoxib causes regression and atrophy of the endometriotic lesions and is as effective as a GnRH agonist with an accompanying decrease in the VEGF levels.

Decreased levels of interleukin-18 in peritoneal fluid but not in serum of patients with endometriosis

OBJECTIVE

To determine the concentrations of interleukin-18 (IL-18) in peritoneal fluid and serum in patients with endometriosis in comparison with the control group.

DESIGN

A prospective analytical study.

SETTING

The obstetrics and gynecology department of an academic training hospital.

PATIENT(S)

Forty-four patients who underwent laparoscopic surgery for benign gynecologic diseases.

INTERVENTION(S)

Specimens of peripheral blood and peritoneal fluid were obtained before and during laparoscopic procedures, and the levels of IL-18 were analyzed.

MAIN OUTCOME MEASURE(S)

The concentrations of IL-18 in peritoneal fluid and serum were correlated with the presence of endometriosis, disease stage, and the phase of the menstrual cycle.

RESULT(S)

Interleukin-18 was detectable in 98% of the peritoneal specimens and 84% of the serum specimens of the patients tested. Peritoneal fluid IL-18 concentrations were statistically significantly lower in patients with endometriosis than in patients without endometriosis; the difference in serum IL-18 levels showed no statistically significant difference between the patients with and without endometriosis. The concentrations of IL-18 in peritoneal fluid and serum were not correlated with the stage of endometriosis or the phase of the menstrual cycle.

CONCLUSION(S)

Our results suggest that the decreased levels of IL-18 in peritoneal fluid in patients with endometriosis as compared with the control group may play an important role in the pathogenesis of this disease.

Immunology of endometriosis

Endometriosis is a benign gynecologic disorder characterized by the ectopic growth of misplaced endometrial cells. A unifying hypothesis to explain endometriosis has not been elucidated as yet but numerous investigations have implicated disturbances in the immune response as fundamental to its etiology and pathogenesis. Clearly, the immune system is involved in endometriosis. It is not clear, however, whether and to what extent this involvement is a primary response leading to the initiation, promotion, and progression of the disease or a secondary response to the ectopic endometrial growth in an attempt to restore homeostasis. Thus, although numerous studies have shown alterations in cell-mediated and humoral immunity in subjects with endometriosis, the importance of these changes remains obscure. This review considers the past two decades of investigation of immune function changes in women with endometriosis with the expectation that this information will ultimately provide the basis for developing new approaches to patient management.

Expression of transforming growth factor β1 in nerve fibers is related to dysmenorrhea and laparoscopic appearance of endometriotic implants

OBJECTIVE

To quantify the expression of transforming growth factor beta1 in nerve fibers in endometriotic lesions and to correlate it with dysmenorrhea and appearance of endometriotic implants.

DESIGN

Prospective comparative study.

SETTING

University hospital.

PATIENT(S)

Peritoneal endometriotic specimens obtained from 35 patients diagnosed with endometriosis were compared with biopsies of normal peritoneum from 10 patients without endometriosis.

INTERVENTION(S)

Endometriosis-associated dysmenorrhea for each patient was evaluated before surgery using a 10-point visual analog scale, which was followed by a laparoscopic staging of the patient's endometriosis.

MAIN OUTCOME MEASURE(S)

Immunohistochemical analysis of the peritoneal endometriotic specimens evaluated the maximal intensity of staining (INTMMAX) of TGFbeta1, defined as higher staining intensity found within a selected structure.

RESULT(S)

When the nerve fibers of endometriotic lesions were compared with those of normal peritoneum, statistically significant differences were found in the INTMMAX of TGFbeta1. Greater TGFbeta1 INTMMAX was found in red lesions and deep endometriotic foci than in black lesions and normal peritoneum. A statistically significant relationship was found between the TGFbeta1 INTMMAX score and dysmenorrhea; a relationship also was found to the color of the lesions.

CONCLUSION(S)

The physical appearance of endometriotic implants and the severity of dysmenorrhea appear to be related to the expression of TGFbeta1 in nerve fibers.

Transactivation of steroidogenic acute regulatory protein in human endometriotic stromalcells is mediated by the prostaglandin EP2 receptor

Steroidogenic acute regulatory protein (StAR) regulates the first committed step in the biosynthesis of steroids, and thus aberrant expression of StAR in endometriotic implants plays a critical role in the etiology of endometriosis. However, the mechanism responsible for abnormal expression of StAR in ectopic endometriotic tissues remains unknown. In the present study, we demonstrate that prostaglandin (PG) E(2) stimulates StAR protein expression at the cellular and molecular levels. PGE(2) caused a rapid increase in StAR expression that involves activation of the EP2 receptor-coupled protein kinase A pathway. Activation of EP2 receptor-induced phosphorylation of ERK and cAMP response element binding protein (CREB). However, activation of ERK did not involve in CREB phosphorylation or concomitantly StAR expression. Phosphorylation of CREB induced by PGE(2) increased the recruitment of CREB binding protein and thus histone H3 acetylation. Chromatin immunoprecipitation experiments showed that acetylated histone H3 bound to the proximal region of the StAR promoter was increased after 30 min treatment with PGE(2), and this was mirrored by an increase in nascent StAR RNA transcription. Treatment with the histone deacetylase inhibitor, tricostatin A, enhanced PGE(2)-induced nascent StAR RNA transcription. We conclude that increased histone H3 acetylation involving the EP2 receptor, protein kinase A, CREB, and CREB binding protein is responsible for PGE(2)-induced StAR gene activation in endometriotic stromal cells. Our current report may provide new insights in understanding mechanism of abnormally local production of estrogen and the etiology of endometriosis.

Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible, glutathione-activated, membrane-bound prostaglandin F(2alpha)-synthetic activity

Distinct functional coupling between cyclooxygenases (COXs) and specific terminal prostanoid synthases leads to phase-specific production of particular prostaglandins (PGs). In this study, we examined the coupling between COX isozymes and PGF synthase (PGFS). Co-transfection of COXs with PGFS-I belonging to the aldo-keto reductase family into HEK293 cells resulted in increased production of PGF(2alpha) only when a high concentration of exogenous arachidonic acid (AA) was supplied. However, this enzyme failed to produce PGF(2alpha) from endogenous AA, even though significant increase in PGF(2alpha) production occurred in cells transfected with COX-2 alone. This poor COX/PGFS-I coupling was likely to arise from their distinct subcellular localization. Measurement of PGF(2alpha)-synthetic enzyme activity in homogenates of several cells revealed another type of PGFS activity that was membrane-bound, glutathione (GSH)-activated, and stimulus-inducible. In vivo, membrane-bound PGFS activity was elevated in the lung of lipopolysaccharide-treated mice. Taken together, our results suggest the presence of a novel, membrane-associated form of PGFS that is stimulus-inducible and is likely to be preferentially coupled with COX-2.

Characterization and identification of cytochrome P450 metabolites of arachidonic acid released by human peritoneal macrophages obtained from the pouch of Douglas

Cytochrome P450 metabolism of arachidonic acid (AA) was investigated in human peritoneal macrophages which play a central role in chronic pelvic diseases in women (for example in endometriosis). The formation of eicosanoids other than prostaglandins (PGs) by these cells is still unknown. In non-activated macrophages obtained from women in the reproductive age, the main [(3)H]-AA metabolites coeluted with epoxyeicosatrienoic acids, dihydroxyeicosatrienoic acids (DHETs) and hydroxyeicosatetraenoic acids (HETEs) in reverse-phase HPLC. After zymosan activation a shift to PGs pathway was observed. Treatment with low doses of 2,3,7,8-tetrachlorodibenzo- p -dioxin increased the formation of a metabolite coeluting with 5,6-DHET. By gas chromatography/mass spectrometry 5,6-DHET (after beta-naphthoflavone induction), and 14,15-DHET as well as 11,12-DHET (after AA stimulation) were identified as major epoxygenase metabolites, respectively. The enantioselective formation of 12(S)-HETE was demonstrated by chiral-phase HPLC. Our findings demonstrate that non-activated peritoneal macrophages produce substantial amounts of bioactive cytochrome P450 metabolites of AA.

COX-2 inhibitors and their role in gynecology

This review summarizes current knowledge about the roles of cyclooxygenases and prostaglandins in reproductive medicine. With the development of COX-2 specific inhibitors, new therapeutic options are available to obstetricians and gynecologists, offering better-tolerated alternatives to conventional NSAIDs. The analgesic effectiveness of COX-2 specific inhibitors is well established, and they are already in use in a range of painful conditions. Both celecoxib and valdecoxib are indicated for the treatment of primary dysmenorrhea, and may be effective in postoperative pain, including hysterectomy, and pain associated with endometriosis. There is also speculation that COX-2 specific inhibitors may be effective tocolytic agents without the risks to the fetus seen with conventional NSAIDs. The role of COX-2 in oncogenesis is also under investigation, and COX-2 specific inhibitors may eventually be used in the prevention and treatment of gynecologic malignancies.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to describe the two types of cylooxygenase enzymes (COX), to list the effects and side effects of NSAIDs and COX-2 medications, and to outline the various changes in COX expression during pregnancy.

Alterations in expression of endometrial endothelial nitric oxide synthase and alpha(v)beta(3) integrin in women with endometriosis

OBJECTIVE

To determine the expression of endometrial endothelial nitric oxide synthase (eNOS) protein and alpha(v)beta(3) integrin in patients with and without endometriosis.

DESIGN

Case-control cohort study.

SETTING

University-based tertiary care center.

PATIENT(S)

Endometrial biopsy samples were obtained from 9 fertile women with regular cycles and 30 infertile women with varying severity of endometriosis. Peritoneal fluid levels of nitric oxide were determined in 13 infertile women with a normal pelvis and 12 infertile women with endometriosis.

MAIN OUTCOME MEASURE(S)

Expression of eNOS and alpha(v)beta(3) integrin protein in the endometrium and peritoneal fluid levels of nitric oxide.

RESULTS

In patients with endometriosis, expression of eNOS was significantly increased in the glandular and luminal epithelium, with no significant changes in the stroma. Peritoneal fluid levels of nitric oxide were unchanged, and expression of alpha(v)beta(3) integrin expression in glandular and luminal epithelium was significantly decreased compared with controls. A significant negative correlation was observed between luminal expression of eNOS and alpha(v)beta(3) integrin and between glandular expression of eNOS and luminal expression of alpha(v)beta(3) integrin.

CONCLUSION(S)

The nitric oxide pathway may play a role in the pathogenesis of endometriosis.

Premenstrual and menstrual changes in the macaque and human endometrium: relevance to endometriosis

According to current theory, endometriosis is initiated during retrograde menstruation when menstrual fragments flow out of the fimbriated end of the fallopian tubes and become established on the ovarian surface or other sites in the peritoneal cavity. In recent years, new data have accumulated on the properties of menstruating tissue itself, and several laboratories agree that this tissue is rich in matrix metalloproteinases (MMPs) that may facilitate endometriotic implantation. Recently, we found that vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 (KDR) were dramatically upregulated in the stromal cells of the superficial endometrial zones by progesterone (P) withdrawal during the premenstrual phase. A unique role of VEGF at this stage of the cycle may be to stimulate MMP expression in stromal cells because VEGF, KDR, and MMPs were all coordinately induced in these cells in the superficial zone of the primate endometrium by P withdrawal. The rich content of MMPs and VEGF in the menstrual fragments could facilitate attachment and angiogenesis of menstrual fragments in ectopic sites. In addition, a variety of chemokines, cytokines, and cellular regulators are induced by P withdrawal in the premenstrual human endometrium. These include NFKB, prostaglandins, interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), and monocyte chemotactic peptide-1 (MCP-1), among others. The perivascular expression of several of these factors may facilitate the rapid invasion of leukocytes into the endometrium, especially in the superficial zones. Consequently, menstrual fragments may be rich in IL-8 and MCP-1, both of which would add to the angiogenic potential of such fragments in ectopic sites. In sum, menstrual tissue is rich in VEGF, KDR, MMPs, leukocytes, chemokines, cytokines, and prostaglandins, all factors that may facilitate attachment and angiogenesis when menstrual fragments exit from the tubes and implant on pelvic sites. Additional research on these and other factors in premenstrual and menstrual endometrium may deepen our understanding of both the establishment and progression of this debilitating disease.

High omega-3:omega-6 fatty acid ratios in culture medium reduce endometrial-cell survival in combined endometrial gland and stromal cell cultures from women with and without endometriosis

OBJECTIVE

To study the effects of omega-3 and omega-6 polyunsaturated fatty acid (PUFA) on in vitro proliferation of endometrial cells and their production of the cytokine interleukin-8 (IL-8).

DESIGN

In vitro study.

SETTING

Obstetrics and gynecology department, University of Aberdeen.

PATIENT(S)

Women attending an infertility clinic.

INTERVENTION(S)

In vitro cell cultures using culture mediums supplemented with normal and high ratios of omega-3 PUFA and omega-6 PUFA.

MAIN OUTCOME MEASURE(S)

In vitro survival and production of IL-8 by dispersed endometrial cells.

RESULT(S)

In vitro survival of endometrial cells from women with and without endometriosis was significantly reduced in the presence of high omega-3:omega-6 PUFA ratios compared with cells incubated in the absence of fatty acids, in balanced omega-3:omega-6 PUFA ratios, and in high omega-6:omega-3 PUFA ratios. Endometrial cells from women with endometriosis secreted higher concentrations of IL-8, especially in the presence of high omega-3:omega-6 PUFA ratios.

CONCLUSION(S)

omega-3 PUFA may have a suppressive effect on the in vitro survival of endometrial cells and omega-3 PUFA be useful in the management of endometriosis by reducing the inflammatory response and modulating cytokine function.

A randomized, prospective, controlled study of laparoscopic dye studies and selective salpingography as diagnostic tests of fallopian tube patency

OBJECTIVE

To determine and compare the relative merits of laparoscopic dye (LD) studies and selective salpingography (SS) as diagnostic tests of fallopian tube patency.

DESIGN

Randomized, prospective, controlled study.

SETTING

University-associated assisted reproduction unit.

PATIENT(S)

Two hundred seventy-eight women undergoing investigation of infertility.

INTERVENTION(S)

Allocation to the performance of either LD studies followed by SS or SS followed by LD studies conducted sequentially under general anesthesia.

MAIN OUTCOME MEASURE(S)

Detection of fallopian tube occlusion, including the site of obstruction and evidence of peritubal or pelvic disease.

RESULT(S)

When diagnosis was compared by the first test used, 16 (11.9%) of 135 patients had proximal tubal occlusion at LD studies versus 5 (3.6%) of 138 at SS. Twelve (5.6%) of 122 patients had distal tubal occlusion at LD studies versus 14 (10.5%) of 133 at SS. Fifteen (11.1%) of 135 patients had peritubal disease at LD studies versus 3 (2.52%) of 119 at SS. When diagnosis was compared by individual tubes, the results were similar. Among patients who had proximal occlusion and otherwise normal tubes by both methods, endometriosis was present in 72.2%.

CONCLUSION(S)

Selective salpingography is a better diagnostic test of proximal tubal occlusion than are LD studies. There is no difference between SS and LD studies as a diagnostic test of distal tubal occlusion. Laparoscopic dye studies are a better diagnostic test for assessing peritubal disease than is SS. There may be an association between endometriosis and proximal tubal occlusion. Selective salpingography and LD studies are complementary investigations of the fallopian tubes.