Elevated concentration and biologic activity of monocyte chemotactic protein-1 in the peritoneal fluid of patients with endometriosis**Supported by grant MT-12541 from the Medical Research Council, Ottawa, Ontario, Canada. ††Presented in part at the 4th World Congress of Gynecological Endocrinology, Madonna di Campiglio, Italy, February 12 to 19, 1995. ‡‡The following individuals were part of the gynecologic investigation group, Hôpital Saint-François d’Assise, Québec, Québec, Canada: Jacques Bergeron, M.D., Marc Bureau, M.D., Georges Quesnel, M.D., and Marc Villeneuve, M.D

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Activation of the CXCL16/CXCR6 Axis by TNF-α Contributes to Ectopic Endometrial Stromal Cells Migration and Invasion

The activation of systemic and local inflammatory mechanisms, including elevated levels of chemokines and proinflammatory cytokines in endometriosis progression, is becoming more evident in the recent years. Here, we report the involvement of CXC chemokine 16 (CXCL16) and its sole receptor, CXC chemokine receptor 6 (CXCR6), in pathophysiology of endometriosis. Expression of CXCL16, but not CXCR6, was significantly upregulated in endometriotic lesions when compared to control endometrium. Additionally, serum CXCL16 was significantly elevated in women with endometriosis when compared to control group. Moreover, blockade of the CXCL16/CXCR6 axis by CXCR6 small-interfering RNA reduced the migration and invasion of ectopic endometrial stromal cells (EESCs) followed by decreased phosphorylation of ERK1/2. Furthermore, TNF-α treatment induced the expression of CXCL16 in EESCs. In conclusion, these results suggest that CXCL16/CXCR6 axis, whose expression was enhanced by TNF-α, may be associated with the increased motility of EESCs, through regulation of ERK1/2 signaling, thus contributing to the development of endometriosis. These findings indicate that the CXCL16/CXCR6 axis may contribute to the progression of endometriosis and could be served as a potential target for diagnosis and treatment.

Pain Symptoms and Peritoneal Fluid Cytokine and Marker Concentrations in Women with and without Endometriosis

Purpose

Endometriosis is not only associated with infertility, it is also a common cause of pain in women, leading to work absenteeism and a reduced quality of life. The objective of this study was to confirm the increased peritoneal fluid (PF) concentration of several cytokines in endometriosis patients, to investigate their association with pain levels, and to identify new biological markers in the PF which are neurostimulatory and thus responsible for the appearance and severity of different types of pain.

Methods

Our sample group included 111 patients with histologically confirmed endometriosis and 47 controls undergoing laparoscopy for reasons of abdominal pain or infertility. They rated their pain during menstruation, during sexual intercourse and general lower abdominal pain prior to undergoing surgery in our clinic using a visual analogue scale. During laparoscopy, PF was aspirated. Marker cytokine concentrations were measured by immunoassay and correlated to the Revised American Fertility Society (rAFS) stage of endometriosis and to the pain level using non-parametric methods.

Results

Differences were found between the correlations of the peritoneal fluid levels of many cytokines with dysmenorrhea or lower abdominal pain, and with the presence of severe endometriosis (rAFS III+IV). Glycodelin and osteoprotegerin (OPG) show the strongest associations with menstrual pain, while IL-8, MCP-1 and OPG were correlated to the stage of endometriosis. Low density cytokine protein arrays did not contribute to finding new markers for endometriosis and pain.

Conclusions

These findings illustrate the large variation of cytokine levels between patients. Glycodelin, IL-8 and OPG are the most likely targets for further investigations towards their future clinical use.

Bone Marrow Stem Cell Chemotactic Activity Is Induced by Elevated CXCl12 in Endometriosis

Endometriosis is an inflammatory gynecological disorder caused by the growth of endometrial tissue outside the uterus. Endometriosis produces chemokines, including CXCL12, that attract bone marrow cells to the lesions. In this study, we describe the expression, localization, and chemotactic activity of CXCL12 in endometriotic lesions. Biopsies were collected both from women with endometriosis undergoing laparoscopy and control endometrium from women without endometriosis. Expression of CXCl12 and CXCR4 messenger RNA was increased approximately 4- and 6-fold, respectively, in endometriosis compared to eutopic endometrium. Immunohistochemistry of lesions revealed that CXCR4 was expressed in the stroma and epithelium in both endometriosis and control eutopic endometrium. The level of CXCR4 protein expression was significantly higher in all cellular compartments of the endometriotic lesions compared to control endometrium. CXCL12 protein expression was also higher in endometriotic lesions and was greatest in the epithelial compartment. CXCL12 was increased more in the condition media of cultured endometriosis than in controls as measured by enzyme-linked immunosorbent assay. Transwell chamber migration was used to demonstrate 2-fold increased chemoattraction of mouse bone marrow stem cells toward CXCL12 in the endometriotic-conditioned medium compared with eutopic endometrium. Our results indicate that a preferential recruitment of stem cells to endometriosis can explain how endometriosis outcompetes eutopic endometrium in recruiting the limited supply of circulating stem cells. The CXCL12/CXCR4 signaling axis is a potential target for the treatment of endometriosis and its associated disorders.

Does dienogest influence the inflammatory response of endometriotic cells? A systematic review

OBJECTIVE AND DESIGN

A systematic review of all literature was done to assess the ability of the progestin dienogest (DNG) to influence the inflammatory response of endometriotic cells.

MAIN OUTCOME MEASURES

In vitro and in vivo studies report an influence of DNG on the inflammatory response in eutopic or ectopic endometrial tissue (animal or human).

RESULTS

After strict inclusion criteria were satisfied, 15 studies were identified that reported a DNG influence on the inflammatory response in endometrial tissue. These studies identified a modulation of prostaglandin (PG) production and metabolism (PGE2, PGE2 synthase, cyclo-oxygenase-2 and microsomal PGE synthase-1), pro-inflammatory cytokine and chemokine production [interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, monocyte chemoattractant protein-1 and stromal cell-derived factor-1], growth factor biosynthesis (vascular endothelial growth factor and nerve growth factor) and signaling kinases, responsible for the control of inflammation. Evidence supports a progesterone receptor-mediated inhibition of the inflammatory response in PR-expressing epithelial cells. It also indicated that DNG inhibited the inflammatory response in stromal cells, however, whether this was via a PR-mediated mechanism is not clear.

CONCLUSIONS

DNG has a significant effect on the inflammatory microenvironment of endometriotic lesions that may contribute to its clinical efficacy. A better understanding of the specific anti-inflammatory activity of DNG and whether this contributes to its clinical efficacy can help develop treatments that focus on the inhibition of inflammation while minimizing hormonal modulation.

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.

Can platelet indices be new biomarkers for severe endometriosis?

Objective. The aim of this study was to investigate whether platelet indices-mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) would be useful as noninvasive biomarkers for determining the severity of endometriosis. Methods. A retrospective review of the medical charts of 164 patients diagnosed with endometriosis and who were operated on between 2001 and 2013 was performed. The stage of endometriosis was determined according to revised American Society for Reproductive Medicine criteria. Results. In patients with advanced endometriosis (Stages 3-4), PLT, PCT levels were found to be significantly higher and MPV, PDW values to be significantly lower when compared to initial endometriosis (Stages 1-2). In addition, there was a significant positive correlation between PLT (r: 0.800, P: 0.001) and PCT (r: 0.727, P: 0.002) and the inflammatory marker white blood cell count (WBC). Conclusion. Our finding may not sufficient for employing platelet indices solely in this differential diagnosis, but our finding could provide a suggestion for clinical physicians so that attention is paid to the value of platelet indices and that these may be taken into account when making decisions about the initial or advanced stages of endometriosis.

Biomarkers of endometriosis

BACKGROUND

Diagnosis of endometriosis is surgical through laparoscopy, which is invasive, costly and associated with potential complications.

OBJECTIVES

A non-invasive test for diagnosis of endometriosis will focus the use of laparoscopy on women who are highly suspected of having endometriosis. This review includes studies about different biomarkers for endometriosis and their potential for the non-surgical diagnosis of this disease.

METHODS

This review covers studies that investigated different biomarkers in blood or endometrium. Studies that identified definite cutoff points and evaluated the diagnostic performance of the biomarker as a blood test for endometriosis are focused on.

RESULTS/CONCLUSIONS

Some of the markers investigated showed a good specificity, none of them showed a high sensitivity. More multi-center studies involving larger numbers of patients are required to identify the most useful biomarker.

Analysis of cytokines in the peritoneal fluid of endometriosis patients as a function of the menstrual cycle stage using the Bio-Plex® platform

OBJECTIVE

Endometriosis is a painful disease affecting 10-15% of reproductive-age women. Concentrations of several cytokines and angiogenic factors in peritoneal fluid (PF) have been found to correlate with the severity of the disease. However, levels of some analytes vary across the menstrual cycle, and an ideal biomarker of endometriosis has not yet been identified. We have compared the PF concentrations of different cytokines in proliferative and secretory phases in women with and without the disease using the Bio-Plex platform.

METHODS

PF was aspirated during laparoscopy (N = 133) and the PF concentrations of 18 cytokines from Bio-Plex panels I and II determined with the serum protocol.

RESULTS

Increased PF concentrations of IL-6, IL-18, eotaxin, and MCP-1 were found in endometriosis with no changes with menstrual cycle. Levels of IL-12(p70), ICAM-1, and GRO-α were higher in the secretory phase, while eotaxin concentrations were lower.

CONCLUSION

Of the 18 cytokines tested, IL-6, IL-18 and MCP-1 were the best PF markers of endometriosis.

CD82 gene suppression in endometrial stromal cells leads to increase of the cell invasiveness in the endometriotic milieu

Tetraspanin CD82 is a wide-spectrum tumor metastasis suppressor that inhibits motility and invasiveness of cancer cells. Endometriosis is a benign gynecological disorder, but appears malignant behaviors including invasion, ectopic implantation and recurrence. This study is to elucidate the role of CD82 expression regulation in the pathogenesis of endometriosis. The short interfering RNA silence was established to analyze the roles of CD82, chemokine CCL2, and its receptor CCR2 in the invasiveness of endometrial stromal cells (ESCs). We have found that the mRNA and protein levels of CD82 in the primary normal ESCs from endometrium without endometriosis are significantly higher than that of the primary ESCs from eutopic endometrium and ectopic tissue. CD82 inhibits the invasiveness of ESCs by downregulating CCL2 secretion and CCR2 expression via mitogen-activated protein kinase (MAPK) and integrinβ1 signal pathway, and in turn upregulating the expression of TIMP1 and TIMP2 in an autocrine manner. The combination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with 17β-estradiol can promote the invasion of ESCs via suppressing CD82 expression and stimulating CCL2 secretion and CCR2 expression, and the enhanced interaction of CCL2-CCR2 recruits more macrophages into the ectopic milieu in a paracrine manner, which further downregulates CD82 expression in the ectopic ESCs. Our study has demonstrated for the first time that the abnormal lower CD82 expression in ESCs induced by TCDD and estrogen may be an important molecular basis of endometriosis pathogenesis through enhancing the CCL2 secretion and CCR2 expression and the invasion of ESCs via MAPK and integrinβ1 signal pathway.

Endometriosis: the role of neuroangiogenesis

Endometriosis is a common cause of pelvic pain and infertility, affecting ∼10% of reproductive-age women. Annual costs for medical and surgical care in the United States exceed $20 billion. The disorder is characterized by implants of endometrial tissue outside the uterine cavity. Endometriotic lesions induce a state of chronic peritoneal inflammation, accompanied by elevated prostaglandin, cytokine, and growth factor concentrations. The current therapy is surgical ablation of ectopic implants and hormones that block the hypothalamic-pituitary-ovarian axis, but these approaches are expensive, carry perioperative risks, or have unpleasant side effects of hypoestrogenism. Recent evidence indicates that ectopic endometriotic implants recruit their own unique neural and vascular supplies through neuroangiogenesis. It is believed that these nascent nerve fibers in endometriosis implants influence dorsal root neurons within the central nervous system, increasing pain perception in patients. We consider the mechanisms and therapeutic implications of neuroangiogenesis in these lesions and propose potential treatments for the control or elimination of endometriosis-associated pain.

The mRNA-binding protein HuR is regulated in the menstrual cycle and repressed in ectopic endometrium

Cytokines modulate turnover of the endometrium during the menstrual cycle and contribute to the pathogenesis of endometriosis. Gene expression for cytokines is often regulated by proteins that bind to adenosine- and uridine-rich elements (AREs) in their transcripts to stabilize or destabilize bound messenger RNAs (mRNAs). HuR/ELAVL1 is an RNA-binding protein that stabilizes ARE-containing mRNAs. We hypothesized that HuR might play a role in regulating cytokine expression during the menstrual cycle and in endometriosis and characterized the expression and regulation of HuR in eutopic and ectopic human endometrium. Tissue sections obtained from normal (n = 23) and ectopic (n = 16) endometrium were immunostained for HuR, and staining intensity was evaluated by HSCORE. Cultured stromal cells isolated from normal endometrium were treated with vehicle, estradiol (E2), progesterone (P), E2 + P, tumor necrosis factor-α (TNF-α), and interleukin 1β (IL-1β) for 24 hours, and HuR expression was determined by Western blot. HuR immunoreactivity was significantly lower in the early proliferative and late secretory phases (157.5 ± 11.08 and 190.0 ± 15.2, respectively), compared to the mid-late proliferative (270.0 ± 8.0) and early-mid secretory phases (256.6 ± 20.2; P < .01, analysis of variance [ANOVA]). Furthermore, HuR expression was significantly lower in ectopic endometrial cells compared to normal endometrium in mid-late proliferative and early-mid-secretory phases (P < .01). Estrogen, P, or cytokines did not alter HuR expression in cultured endometrial stromal cells. Increased HuR levels in the mid-menstrual phases are likely to contribute to reduced mid-cycle cytokine expression and enhanced cellular survival in eutopic endometrium. In ectopic endometrium, elevated cytokine levels associated with endometriosis likely reduce HuR expression.

Basal and steroid hormone-regulated expression of CXCR4 in human endometrium and endometriosis

Endometriosis is associated with activation of local and systemic inflammatory mechanisms, including increased levels of chemokines and other proinflammatory cytokines. We have previously reported increased gene expression of chemokine receptor 4 (CXCR4), the receptor for CXCL12, in lesions of the rat model of endometriosis. The CXCR4-CXCL12 axis has been shown to have both immune (HIV infection, lymphocyte chemotaxis) and nonimmune functions, including roles in tissue repair, angiogenesis, invasion, and migration. There is evidence indicating that these mechanisms are also at play in endometriosis; therefore, we hypothesized that activation of the CXCR4-CXCL12 axis could be responsible, at least in part, for the survival and establishment of endometrial cells ectopically. Immunohistochemistry (IHC) showed that CXCR4 protein levels were significantly higher in endometriotic lesions compared to the endometrium of controls. Next, we determined basal gene and protein expression of CXCR4 and CXCL12 and regulation by estradiol (E2) and/or progesterone (P4) in endometrial cell lines using quantitative polymerase chain reaction (qPCR), and Western blots. Basal CXCR4 gene expression levels were higher in epithelial versus stromal cells; conversely, CXCL12 was expressed at higher levels in stromal vs epithelial cells. CXCR4 gene expression was significantly downregulated by ovarian steroid hormones in endometrial epithelial. These data suggest that steroid modulation of CXCR4 is defective in endometriosis, although the specific mechanism involved remains to be elucidated. These findings have implications for future therapeutic strategies specifically targeting the inflammatory component in endometriosis.

Interleukin-1 stimulates macrophage migration inhibitory factor secretion in ectopic endometrial cells of women with endometriosis

PROBLEM

Macrophage migration inhibitory factor (MIF), a potent immuno-modulatory, angiogenic and tissue remodeling factor, is markedly expressed in ectopic endometrial implants and may play key role in the capability of this tissue to grow and develop into the host tissue. The objective of this study was to determine whether macrophage-derived cytokines, such as interleukin (IL)-1, which is overproduced by endometriosis women's peritoneal macrophages and found in elevated concentration in their peritoneal fluid, may play a role in MIF synthesis and secretion by ectopic endometrial cells.

METHODS OF STUDY

Primary cultures of endometriotic cells exposed to IL-1beta and evaluation of MIF protein by immunocytofluorescence and ELISA, and mRNA by quantitative real-time PCR and nuclear transcription assays (run-on).

RESULTS

Interleukin-1beta acts rapidly on endometriotic cells and stimulated MIF secretion and mRNA steady-state levels in a dose and time-dependent manner. IL-1beta treatment had no significant effect on MIF mRNA half-life and stability, but acted predominantly by up-regulating MIF gene transcription as assessed by run-on.

CONCLUSION

These data clearly indicate that IL-1 can be involved in the up-regulation of MIF expression by ectopic endometrial implants. Such an interaction between IL-1 and MIF may have an important impact on endometriotic cell growth and endometriosis pathophysiology.

Neuroendocrine-immune disequilibrium and endometriosis: an interdisciplinary approach

Endometriosis, a chronic disease characterized by endometrial tissue located outside the uterine cavity, affects one fourth of young women and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology and effective treatment strategies of endometriosis is still largely elusive. Inadequate immune and neuroendocrine responses are significantly involved in the pathophysiology of endometriosis, and key findings are summarized in the present review. We discuss here the role of different immune mechanisms particularly adhesion molecules, proteinglycan interactions, and pro-angiogenic mediators in the development and progression of the disease. Finally, we introduce the concept of endometrial dissemination as result of a neuroendocrine-immune disequilibrium in response to high levels of perceived stress caused by cardinal clinical symptoms of endometriosis.

Laser capture microdissection and cDNA array analysis of endometrium identify CCL16 and CCL21 as epithelial-derived inflammatory mediators associated with endometriosis

BACKGROUND

Understanding the pathophysiology of chemokine secretion in endometriosis may offer a novel area of therapeutic intervention. This study aimed to identify chemokines differentially expressed in epithelial glands in eutopic endometrium from normal women and those with endometriosis, and to establish the expression profiles of key chemokines in endometriotic lesions.

METHODS

Laser capture microdissection isolated epithelial glands from endometrial eutopic tissue from women with and without endometriosis in the mid-secretory phase of their menstrual cycles. Gene profiling of the excised glands used a human chemokine and receptor cDNA array. Selected chemokines were further examined using real-time PCR and immunohistochemistry.

RESULTS

22 chemokine/receptor genes were upregulated and two downregulated in pooled endometrial epithelium of women with endometriosis compared with controls. CCL16 and CCL21 mRNA was confirmed as elevated in some women with endometriosis compared to controls on individual samples. Immunoreactive CCL16 and CCL21 were predominantly confined to glands in eutopic and ectopic endometrium: leukocytes also stained. Immunoreactive CCL16 was overall higher in glands in ectopic vs. eutopic endometrium from the same woman (P < 0.05). Staining for CCL16 and CCL21 was highly correlated in individual tissues.

CONCLUSION

This study provides novel candidate molecules and suggests a potential local role for CCL16 and CCL21 as mediators contributing to the inflammatory events associated with endometriosis.

Expression of interleukin-8 and monocyte chemotactic protein-1 in adenomyosis

BACKGROUND

To clarify the inflammatory nature of adenomyosis, we aimed to investigate the expression of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) by immunohistochemistry to determine their putative role in pathophysiology of adenomyosis.

METHODS

Adenomyosis samples, with their eutopic endometrium, were collected from 30 women undergoing hysterectomy. Endometrium from 27 women without adenomyosis were also collected as a control group. Samples were grouped according to the menstrual cycle phase and examined by immunohistochemistry for IL-8 and MCP-1.

RESULTS

In normal endometrium, secretory phase samples expressed higher levels of epithelial IL-8 than in proliferative phase samples (P = 0.01), and we observed a trend for an increased epithelial MCP-1 expression in the secretory phase samples compared with the proliferative phase samples (P = 0.07). Endometrial samples of women with adenomyosis did not show the same cyclic variation. In the secretory phase, eutopic endometrium of women with adenomyosis expressed lower levels of epithelial IL-8 and MCP-1 compared with normal endometrium (P < 0.05). The expression of epithelial IL-8 and MCP-1 was higher in the adenomyosis foci than the eutopic endometrium (P < 0.05).

CONCLUSIONS

These findings may indicate that an intrinsic abnormality of inflammatory response may be present in eutopic endometrium of women with adenomyosis, and IL-8 and MCP-1 may contribute to the pathophysiology of adenomyosis.

Immunohistochemical localization of insulin-like growth factor-binding protein-3 in eutopic and ectopic endometrial tissues

OBJECTIVE

To evaluate the expression of insulin-like growth factor-binding protein-3 (IGFBP-3) in the eutopic endometrium and in endometriotic lesions.

DESIGN

Retrospective immunohistochemical study.

PATIENT(S)

Twenty-five normal women and 39 women with endometriosis.

INTERVENTION(S)

Endometrial and endometriotic tissue biopsies obtained at laparoscopy.

MAIN OUTCOME MEASURE(S)

Expression of IGFBP-3 assessed by immunohistochemistry.

RESULT(S)

In the endometrium, positive immunostaining of IGFBP-3 was observed both in the stroma and the epithelial glands. The intensity of staining in the glands during the secretory phase was significantly higher in women with endometriosis compared with controls (P = .018). An increased expression of IGFBP-3 over controls was found in stages I and II of the disease (P = .018), whereas in stages III and IV, the difference between controls and women with endometriosis was not significant (P = .300). In endometriotic tissues, a much-marked immunostaining of IGFBP-3 was noted in 90% of the glands and 67% of the stroma without apparent differences related to cycle phase.

CONCLUSION(S)

These data show intense staining of IGFBP-3 in endometriosis lesions and increased expression of the protein in the endometrium of patients with endometriosis compared to controls. This marked expression of IGFBP-3 could be related to its previous finding in the peritoneal fluid and to its potential involvement in the pathophysiology of endometriosis.

Macrophage scavenger receptor(s) and oxidatively modified proteins in endometriosis

OBJECTIVE

To determine whether cultured human peritoneal macrophages have functional scavenger receptor(s) and whether activation of macrophages in endometriosis may involve an increase in scavenger receptor activity.

DESIGN

A controlled clinical study comparing peritoneal fluid (PF) macrophages of women with endometriosis and controls without endometriosis.

SETTING

Women undergoing laparoscopic evaluation and treatment in a tertiary medical center.

PATIENT(S)

Twenty-one women undergoing evaluation for pelvic pain or infertility and 10 women undergoing elective laparoscopic tubal ligation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Evidence for functional macrophage scavenger receptor and evidence of ligands for the scavenger receptor in PF.

RESULT(S)

Peritoneal macrophages of women with endometriosis degrade significantly more endothelial cell-low density lipoprotein (EC-LDL) and copper-oxidized LDL (Cu-LDL) than native LDL. Macrophages of women with endometriosis also incorporate more labeled oleic acid into cholesteryl ester in the presence of oxidized LDL (Ox-LDL) than in the presence of native LDL. Western blot analysis demonstrates the presence of adducts between lipid peroxidation products and proteins in PF of patients with and without endometriosis. The PF of women with endometriosis competes with labeled Ox-LDL for uptake by mouse peritoneal macrophages in a dose-dependent manner.

CONCLUSION(S)

We demonstrate for the first time that human macrophages have functional scavenger receptor(s) and that activation of macrophages in endometriosis involves an increase in scavenger receptor activity. Two lines of evidence indicate the presence of ligands for the scavenger receptor in PF.

Angiogenesis and macrophage activation in endometriosis

Recent studies suggest that the symptoms associated with endometriosis are the result of local peritoneal inflammation. Increased concentrations of activated pelvic macrophages and lymphocytes and the elevated levels of specific cytokines and growth factors reviewed above support this hypothesis. The precise roles of these soluble factors are currently unknown, but we propose that a complex network of endometrial cytokines are normally regulated by hormones produced during the ovulatory cycle. Ectopic endometrial implants also are subject to these same endocrine cues. The secretion of these proinflammatory proteins by endometriosis lesions into the peritoneal microenvironment appears to cause a recruitment of capillaries and activated inflammatory cells to the implant. Future therapeutic strategies directed to ameliorate the inflammatory reaction associated with endometriosis should not ignore the likely physiological actions of many of the same bioactive molecules in normal eutopic endometrial function.

Monocyte chemotactic protein-1 concentration in peritoneal fluid of women with endometriosis and its modulation of expression in mesothelial cells

OBJECTIVE

To investigate monocyte chemotactic protein-1 concentrations in the peritoneal fluid (PF) of women with or without endometriosis, then assess peritoneal mesothelial cells as a potential source of monocyte chemotactic protein-1.

DESIGN

Prospective study.

SETTING

University medical center.

PATIENT(S)

Women with (n = 60) or without (n = 18) endometriosis.

INTERVENTION(S)

First monocyte chemotactic protein-1 levels in PF were measured, then mesothelial cells in culture were treated with cytokines.

MAIN OUTCOME MEASURE(S)

In PF and culture supernatants, monocyte chemotactic protein-1 was measured by ELISA. In vitro monocyte chemotactic protein-1 messenger RNA expression was evaluated by Northern analysis.

RESULT(S)

The median concentration of monocyte chemotactic protein-1 in PF of control women was 137 pg/mL (conversion factor to SI unit, 0.115; range, 12 to 418 pg/mL); that of women with moderate endometriosis was 205 pg/mL (range 65 to 6,000 pg/mL); and that of those with severe endometriosis was 1,165 pg/mL (0 to 2,602 pg/mL). Within the moderate to severe endometriosis group, monocyte chemotactic protein-1 levels were higher in women with untreated endometriosis (354 pg/mL range 0 to 6,000 pg/mL) than in women receiving GnRH agonist (128 pg/mL, range 0 to 216 pg/mL). In the control group, monocyte chemotactic protein-1 levels were higher in the proliferative phase than in the secretory phase. Mesothelial cells produced constitutively monocyte chemotactic protein-1; moreover, both interleukin-1 alpha and tumor necrosis factor-alpha induced higher levels of monocyte chemotactic protein-1.

CONCLUSION(S)

Levels of monocyte chemotactic protein-1 in PF were higher during the proliferative phase than secretory phase of control women and increased in moderate to severe endometriosis. The regulated expression of monocyte chemotactic protein-1 may recruit macrophages into PF and contribute to the pathogenesis of endometriosis.

Chemotaxis of macrophages by a peritoneal fluid protein in women with endometriosis

OBJECTIVE

To expand on a preliminary study comparing the chemotactic potential of peritoneal fluid (PF) from women with and without endometriosis and to characterize this activity via immunosuppressants and a protease.

DESIGN

Case control study.

SETTING

University center.

PATIENT(S)

Fifty-nine women with endometriosis and 44 without, undergoing laparoscopy.

INTERVENTION(S)

Collection of PF, endometriotic, ovarian, and endometrial biopsies at laparoscopy.

MAIN OUTCOME MEASURE(S)

Chemotactic activity of PF was tested via an in vitro assay alone and in the presence of immunosuppressants cyclosporin A (CSA), FK506, rapamycin, and type XVII-b(S-V8) protease and in media incubated with endometriotic, ovarian, or endometrial biopsy specimens.

RESULT(S)

The PF from women with endometriosis had significantly greater chemotactic activity (cells per well, mean +/- SD) than without endometriosis (142 +/- 39 versus 48 +/- 17). Cyclosporin A significantly inhibited the chemotactic activity of the endometriotic PF; FK506 and rapamycin did not. Incubation of media with endometriotic tissue, but not ovarian or endometrial, for > or = 7 hours displayed chemotactic activity. Protease type XVII-b(S-V8) added to endometriotic PF inhibited this chemotactic activity.

CONCLUSION(S)

Peritoneal fluid from patients with endometriosis contains a protein chemotactic factor attracting inflammatory cells into the peritoneal cavity, possibly secreted by endometriotic implants. This chemotactic factor may be a member of the immunophilin family because of its inhibition profile.