Paracrine regulation of matrix metalloproteinase expression in endometriosis

Interleukin-1β induces and accelerates human endometrial stromal cell senescence and impairs decidualization via the c-Jun N-terminal kinase pathway

As the mean age of first-time mothers increases in the industrialized world, inquiries into causes of human reproductive senescence have followed. Rates of ovulatory dysfunction and oocyte aneuploidy parallel chronological age, but poor reproductive outcomes in women older than 35 years are also attributed to endometrial senescence. The current studies, using primary human endometrial stromal cell (ESC) cultures as an in vitro model for endometrial aging, characterize the proinflammatory cytokine, IL-1β-mediated and passage number-dependent effects on ESC phenotype. ESC senescence was accelerated by incubation with IL-1β, which was monitored by RNA sequencing, ELISA, immunocytochemistry and Western blotting. Senescence associated secreted phenotype (SASP) proteins, IL-1β, IL-6, IL-8, TNF-α, MMP3, CCL2, CCL5, and other senescence-associated biomarkers of DNA damage (p16, p21, HMGB1, phospho-γ-histone 2 A.X) were noted to increase directly in response to 0.1 nM IL-1β stimulation. Production of the corresponding SASP proteins increased further following extended cell passage. Using enzyme inhibitors and siRNA interference, these effects of IL-1β were found to be mediated via the c-Jun N-terminal kinase (JNK) signaling pathway. Hormone-induced ESC decidualization, classical morphological and biochemical endocrine responses to estradiol, progesterone and cAMP stimulation (prolactin, IGFBP-1, IL-11 and VEGF), were attenuated pari passu with prolonged ESC passaging. The kinetics of differentiation responses varied in a biomarker-specific manner, with IGFBP-1 and VEGF secretion showing the largest and smallest reductions, with respect to cell passage number. ESC hormone responsiveness was most robust when limited to the first six cell passages. Hence, investigation of ESC cultures as a decidualization model should respect this limitation of cell aging. The results support the hypotheses that "inflammaging" contributes to endometrial senescence, disruption of decidualization and impairment of fecundity. IL-1β and the JNK signaling pathway are pathogenetic targets amenable to pharmacological correction or mitigation with the potential to reduce endometrial stromal senescence and enhance uterine receptivity.

A More Diverse Cervical Microbiome Associates with Better Clinical Outcomes in Patients with Endometriosis: A Pilot Study

Infection-induced chronic inflammation is common in patients with endometriosis. Although microbial communities in the reproductive tracts of patients have been reported, little was known about their dynamic profiles during disease progression and complication development. Microbial communities in cervical mucus were collected by cervical swabs from 10 healthy women and 23 patients, and analyzed by 16S rRNA amplicon sequencing. The abundance, ecological relationships and functional networks of microbiota were characterized according to their prevalence, clinical stages, and clinical features including deeply infiltrating endometriosis (DIE), CA125, pain score and infertility. Cervical microbiome can be altered during endometriosis development and progression with a tendency of increased Firmicutes and decreased Actinobacteria and Bacteroidetes. Distinct from vaginal microbiome, upregulation of Lactobacillus, in combination with increased Streptococcus and decreased Dialister, was frequently associated with advanced endometriosis stages, DIE, higher CA125 levels, severe pain, and infertility. Significantly, reduced richness and diversity of cervical microbiome were detected in patients with more severe clinical symptoms. Clinical treatments against infertility can partially reverse the ecological balance of microbes through remodeling nutrition metabolism and transport and cell-cell/cell-matrix interaction. This study provides a new understanding on endometriosis development and a more diverse cervical microbiome may be beneficial for patients to have better clinical outcomes.

Nanomedicines for Endometriosis: Lessons Learned from Cancer Research

Endometriosis is an incurable gynecological disease characterized by the abnormal growth of endometrium-like tissue, characteristic of the uterine lining, outside of the uterine cavity. Millions of people with endometriosis suffer from pelvic pain and infertility. This review aims to discuss whether nanomedicines that are promising therapeutic approaches for various diseases have the potential to create a paradigm shift in endometriosis management. For the first time, the available reports and achievements in the field of endometriosis nanomedicine are critically evaluated, and a summary of how nanoparticle-based systems can improve endometriosis treatment and diagnosis is provided. Parallels between cancer and endometriosis are also drawn to understand whether some fundamental principles of the well-established cancer nanomedicine field can be adopted for the development of novel nanoparticle-based strategies for endometriosis. This review provides the state of the art of endometriosis nanomedicine and perspective for researchers aiming to realize and exploit the full potential of nanoparticles for treatment and imaging of the disorder.

Expression and Significance of Matrix Metalloproteinase-2 and Matrix Metalloproteinas-9 in Endometriosis

Endometriosis is a chronic benign hormone-dependent condition when the endometrial tissue, identical with the endometrium by its morphological and functional properties, grows outside the borders of the uterine mucous membrane. Recent studies have pointed to the possible role of matrix metalloproteinases (MMPs) in the pathogenesis of endometriosis. We suggested a hypothesis that increased expression of MMPs activity in eutopic and ectopic endometrium of patients with endometriosis might correlate with the presence of endometriotic lesions.

The aim of the study was to evaluate the level of MMP-2 and MMP-9 expression in the ectopic endometrium of women with visible endometriotic lesions and eutopic endometrium in patients with no signs of endometriosis.

The study was conducted on 43 patients. They were divided into two groups. Group 1 included 31 patients with peritoneal/ovarian endometriosis who had undergone laparoscopy and hysteroscopy. Group 2 consisted of 12 patients with leiomyoma, endometrial polyps or relatively healthy patients who had undergone hysterectomy or polypectomy and endometrial curettage.

This study showed statistically higher expression of MMP-2 (1.7783 ± 0.22 immunohistochemistry (IHC) optical density score compared to the control group – 1.41± 0.34, p = 0.0017) and MMP-9 (1.352 ± 0.067 versus 1.85 ± 0.26 in the control group, p = 0.001) in ectopic and eutopic endometrium samples from patients with endometriosis compared to samples taken from patients without endometriosis. A strong correlation between expression of the above-mentioned MMPs (r=0.74 for MMP-2 and r=0.88 for MMP-9) in ectopic and eutopic endometrium might be of promising diagnostic value.

The Pathogenesis of Endometriosis: Molecular and Cell Biology Insights

The etiopathogenesis of endometriosis is a multifactorial process resulting in a heterogeneous disease. Considering that endometriosis etiology and pathogenesis are still far from being fully elucidated, the current review aims to offer a comprehensive summary of the available evidence. We performed a narrative review synthesizing the findings of the English literature retrieved from computerized databases from inception to June 2019, using the Medical Subject Headings (MeSH) unique ID term "Endometriosis" (ID:D004715) with "Etiology" (ID:Q000209), "Immunology" (ID:Q000276), "Genetics" (ID:D005823) and "Epigenesis, Genetic" (ID:D044127). Endometriosis may origin from Müllerian or non-Müllerian stem cells including those from the endometrial basal layer, Müllerian remnants, bone marrow, or the peritoneum. The innate ability of endometrial stem cells to regenerate cyclically seems to play a key role, as well as the dysregulated hormonal pathways. The presence of such cells in the peritoneal cavity and what leads to the development of endometriosis is a complex process with a large number of interconnected factors, potentially both inherited and acquired. Genetic predisposition is complex and related to the combined action of several genes with limited influence. The epigenetic mechanisms control many of the processes involved in the immunologic, immunohistochemical, histological, and biological aberrations that characterize the eutopic and ectopic endometrium in affected patients. However, what triggers such alterations is not clear and may be both genetically and epigenetically inherited, or it may be acquired by the particular combination of several elements such as the persistent peritoneal menstrual reflux as well as exogenous factors. The heterogeneity of endometriosis and the different contexts in which it develops suggest that a single etiopathogenetic model is not sufficient to explain its complex pathobiology.

The bimodal role of matrix metalloproteinases and their inhibitors in etiology and pathogenesis of endometriosis (Review)

Aberrant regulation of matrix metalloproteinases (MMPs) may be the primary cause of endometrial lesion formation in a group of predisposed women. Prospect for the genuine origin of endometriosis is ongoing, since retrograde menstruation leads to presence of endometrial debris in peritoneal cavity of many women, which do not experience endometriosis. Tissue remodeling is regulated precisely by a balance of MMPs and their inhibitors. Interplay between factors enhancing and suppressing matrix turnover is crucial for cyclic preparation of endometrium for embryo implantation, and endometrial shedding and renewal in physiology of primates. Disorders of the regulation of matrix remodeling leads to augmentation of implantation and invasive growth of ectopic endometrial tissue. Moreover, endometriosis-induced changes in the matrix balance leads to adhesion formation, ovulatory dysfunction and fertility impairment. The review summarizes the current knowledge regarding the regulation of extracellular matrix turnover in the physiology of the endometrial cycle and in the development of endometriosis, as well as the pathophysiology of ovulatory dysfunction in endometriotic women. Therapeutic modalities utilizing modulation of tissue remodeling were discussed.

rhTNFR: Fc Suppresses the Development of Endometriosis in a Mouse Model by Downregulating Cell Proliferation and Invasiveness

Tumor necrosis factor α (TNF-α), a proinflammatory cytokine, may play an important role in the pathogenesis of endometriosis; therefore, TNF-α inhibitors potentially have an effect on endometriosis. To investigate the effect of anti-TNF-α treatment on endometriosis, 2 TNF-α inhibitors: recombinant human TNF receptor: Fc fusion protein (rhTNFR: Fc) and TNF-α monoclonal antibody (TNF-α mAb) were used to treat human eutopic endometrial stromal cells (hESCs), and the effects on cell survival, cell cycle, and invasiveness were compared. It was found that rhTNFR: Fc suppressed the TNF-α-induced hESC survival and invasiveness but not TNF-α mAb. Recombinant human TNF receptor: Fc fusion protein decreased the S phase of hESC compared with the TNF-α-treated group. Then, we used a surgically induced mouse model of endometriosis to study the effect of rhTNFR: Fc treatment in vivo. The fluorescence intensity and the size of implanted endometriotic lesions in the mouse model were decreased by rhTNFR: Fc. In conclusion, rhTNFR: Fc suppresses hESC survival and invasiveness and decreases the fluorescence intensity and implant size in the mouse model of endometriosis.

The Targeted Delivery of Interleukin 4 Inhibits Development of Endometriotic Lesions in a Mouse Model

Endometriosis is caused by the displacement of endometrium outside the uterus contributing heavily to infertility and debilitating pelvic pain. Ectopic adhesion and growth are believed to occur under the influence of a favorable hormonal environment and immunological factors. The objective of this study is to analyze the effect of a targeted therapy with an antibody-based pharmacodelivery of interleukin 4 (F8-IL4) in a mouse model of experimentally induced endometriosis. Endometriosis-like lesions were induced in Balb/c mice. The animals were treated intravenously with F8-IL4 or with untargeted IL4 (KSF-IL4). Twelve days after disease induction, the lesions were isolated. A significant reduction in the number of total lesions/mouse and in the total volume of lesions/mouse was observed in mice treated with F8-IL4 compared to controls (P = .029 and P = .006, respectively), while no difference was found between KSF-IL4-treated mice and their controls. Gene expression was evaluated by quantitative real-time polymerase chain reaction. Expression of genes involved in cell adhesion, extracellular matrix invasion, and neovascularization was significantly downregulated in F8-IL4-treated mice compared to their controls (integrin β1: P = .02; metalloproteinase [MMP] 3: P = .02; MMP9: P = .04; vascular endothelial growth factor: P = .04). Gene expression of inflammatory cytokines (tumor necrosis factor α, IL1β, IL1α, and IL6) did not vary in the ectopic lesions isolated from F8-IL4-treated mice compared to their controls. Immunohistochemistry demonstrated a significantly reduced expression of E-cadherin and β-catenin in the lesions of mice treated with F8-IL4. Our results show that the antibody-mediated targeted delivery of IL4 inhibits the development of endometriosis in a syngeneic mouse model by likely impairing adhesion, invasion, and vascularization of the ectopic endometrium.

Endometriosis of the conus medullaris causing cyclic radiculopathy

Intramedullary spinal cord hematomas are a rare neurosurgical pathological entity typically arising from vascular and neoplastic lesions. Endometriosis is an extremely rare cause of intramedullary spinal cord hematoma, with only 5 previously reported cases in the literature. Endometriosis is characterized by ectopic endometrial tissue, typically located in the female pelvic cavity, that causes a cyclical pain syndrome, bleeding, and infertility. In the rare case of intramedullary endometriosis of the spinal cord, symptoms include cyclical lower-extremity radiculopathies and voiding difficulties, and can acutely cause cauda equina syndrome. The authors report a case of endometriosis of the conus medullaris, the first to include radiological, intraoperative, and histopathological imaging. A brief review of the literature is also presented, with discussion including etiological theories surrounding intramedullary endometriosis.

Nuclear localization of matrix metalloproteinases

Matrix metalloproteinases (MMPs) were originally identified as matrixin proteases that act in the extracellular matrix. Recent works have uncovered nontraditional roles for MMPs in the extracellular space as well as in the cytosol and nucleus. There is strong evidence that subspecialized and compartmentalized matrixins participate in many physiological and pathological cellular processes, in which they can act as both degradative and regulatory proteases. In this review, we discuss the transcriptional and translational control of matrixin expression, their regulation of intracellular sorting, and the structural basis of activation and inhibition. In particular, we highlight the emerging roles of various matrixin forms in diseases. The activity of matrix metalloproteinases is regulated at several levels, including enzyme activation, inhibition, complex formation and compartmentalization. Most MMPs are secreted and have their function in the extracellular environment. MMPs are also found inside cells, both in the nucleus, cytosol and organelles. The role of intracellular located MMPs is still poorly understood, although recent studies have unraveled some of their functions. The localization, activation and activity of MMPs are regulated by their interactions with other proteins, proteoglycan core proteins and / or their glycosaminoglycan chains, as well as other molecules. Complexes formed between MMPs and various molecules may also include interactions with noncatalytic sites. Such exosites are regions involved in substrate processing, localized outside the active site, and are potential binding sites of specific MMP inhibitors. Knowledge about regulation of MMP activity is essential for understanding various physiological processes and pathogenesis of diseases, as well as for the development of new MMP targeting drugs.

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.

Endometriotic epithelial cells induce MMPs expression in endometrial stromal cells via an NFkappaB-dependent pathway

OBJECTIVE

To explore the stroma-epithelium interactions in endometriosis and to identify the possible signalling pathways involved in this cross-talk.

DESIGN

Laboratory study via primary cultured endometrial stromal and epithelial cells.

SETTING

University Hospital.

PATIENTS

Fifteen patients with endometriosis confirmed by histopathology were recruited in the study, and 12 women free of endometriosis were used as control group.

INTERVENTION(S)

Specific NFkappaB inhibitor 1-Pyrrolidinecarbodithioic acid ammonium salt (PDTC) was used in cell cultures.

MAIN OUTCOME MEASURE(S)

The expression and secretion of MMP-2, MMP-9, TIMP-1, TIMP-2 and the DNA-binding activity of NFkappaB in normal endometrial stromal cells or in co-cultures with normal or endometriotic epithelial cells from patients with endometriosis.

RESULT(S)

Endometrial epithelial cells induced MMP-9 and MMP-2 expression in normal stromal cells in vitro. In co-cultures with endometriotic epithelial cells, normal endometrial stromal cells expressed and secreted higher MMP-2 (p < 0.05) and MMP-9 (p < 0.05). Specific inhibition of NFkappaB pathway in stromal cells abolished this induction effect by epithelial cells.

CONCLUSION(S)

Endometriotic epithelial cells induce MMPs expression and secretion in normal endometrial stromal cells via an NFkappaB-dependent pathway in vitro. This cross-talk between epithelial cells and stromal cells may facilitate the implantation and extension of the ectopic foci and favour the development of the disease.

Doxycycline causes regression of endometriotic implants: a rat model

BACKGROUND

Doxycycline (Dox) has a number of non-antibiotic properties. One of them is the inhibition of matrix metalloproteinase (MMP) activity. The aim of this study was to assess the effects of Dox in a rat endometriosis model.

METHODS

Endometriosis was surgically induced in 40 rats by transplanting of endometrial tissue. After 3 weeks, repeat laparotomies were performed to check the implants and the animals were randomized into four groups: Group I, low-dose Dox (5 mg/kg/day); Group II, high-dose Dox (40 mg/kg/day); Group III, leuprolide acetate 1 mg/kg single dose, s.c.; and Group VI (controls), no medication. The treatment, initiated on the day of surgery and continuing for 3 weeks, was administered to the study groups. Three weeks later, the rats were euthanized and the implants were evaluated morphologically and histologically for immunoreactivity of MMP-2 and -9, and interleukin-6 (IL-6) concentration in the peritoneal fluid was assayed.

RESULTS

Treatment with leuprolide acetate, or high-dose or low-dose Dox caused significant decreases in the implant areas compared with the controls (P = 0.03, P = 0.006, and P = 0.001, respectively). IL-6 levels in peritoneal fluid decreased in Group I (P = 0.02) and Group III (P < 0.05). MMP H scores were significantly lower in the group that received low-dose Dox in both epithelial and stromal MMP-2 and -9 immunostaining when compared with the control group [P = 0.048, P = 0.002, P = 0.007 and P = 0.002, respectively, MMP-2 (epithelia), MMP-2 (stroma), MMP-9 (epithelia) and MMP-9 (stroma)].

CONCLUSIONS

Low-dose Dox caused regression of endometriosis in this experimental rat model.

Increased expression of c-fos protein associated with increased matrix metalloproteinase-9 protein expression in the endometrium of endometriotic patients

OBJECTIVE

To investigate c-fos and matrix metalloproteinase-9 (MMP-9) expression in the endometrium from women with or without endometriosis throughout the menstrual cycle, and to explore the correlation of c-fos expression with MMP-9 expression and 17beta-E(2) levels in serum.

DESIGN

Molecular studies in human tissue.

SETTING

A women's hospital in China.

PATIENT(S)

Fifty-five premenopausal women (25 with endometriosis and 30 without endometriosis) undergoing laparoscopic surgery or hysterectomy.

INTERVENTION(S)

Eutopic and ectopic endometrium tissue were obtained at the time of surgery. Peripheral sera were also collected on the same day.

MAIN OUTCOME MEASURE(S)

Immunohistochemical localization of c-fos in the endometrium, c-fos and MMP-9 protein levels in the endometrium, and 17beta-E(2) levels in the serum.

RESULT(S)

c-fos protein was predominantly located in the nuclei of glandular epithelial cells and stromal cells. c-fos and MMP-9 protein levels in paired eutopic and ectopic endometria from women with endometriosis were significantly higher than those in the endometrium from women without endometriosis. No significant difference in c-fos or MMP-9 protein levels was observed between paired eutopic and ectopic endometria. c-fos protein levels in endometrium positively correlated with endometrial MMP-9 levels and serum 17beta-E(2) levels.

CONCLUSION(S)

Expression of c-fos in the human endometrium may be regulated by 17beta-E(2), and c-fos may be involved in development of endometriosis by promoting MMP-9 gene expression and subsequently the invasive potential of endometrial explants.

Gelatinase A (MM-2), gelatinase B (MMP-9) and their inhibitors (TIMP 1, TIMP-2) in serum of women with endometriosis: Significant correlation between MMP-2, MMP-9 and their inhibitors without difference in levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in relation to the severity of endometriosis

Endometriosis is a highly prevalent gynecological condition, where the formation of endometriotic foci is linked with locally increased activity of matrix metalloproteinases (MMPs). In the present study, we tested the hypothesis that raised serum levels of MMPs might reflect the severity of endometriosis. We compared serum levels of MMP-2 and MMP-9, and of their tissue inhibitors TIMP-1 and TIMP-2, in infertile women, matched for age and body mass index, with either mild (stage I, END-I; n = 15) or severe endometriosis (stage IV, END-IV; n = 22). There was no difference in the concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 between the analyzed groups. There was, however, a correlation between MMP-9 and TIMP-1 for the combined group (n = 37) (r = 0.48; p = 0.0032) and in women with END-IV (r = 0.51; p = 0.0163), as well as a highly significant correlation between MMP-2 and TIMP-2 for the combined group (r = 0.69; p = 0.0001), END-I (r = 0.51; p = 0.0406) and END-IV groups (r = 0.77; p = 0.0001). There was also a significant correlation between TIMP-1 and TIMP-2 in the combined and END-IV groups (r = 0.39; p = 0.0182 and r = 0.5450; p = 0.0099, respectively). The balance between MMPs and their inhibitors is preserved in the serum of women with endometriosis, but serum concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 cannot be considered to represent a valid measure of the severity of endometriosis.

Inhibiting MMP activity prevents the development of endometriosis in the chicken chorioallantoic membrane model

BACKGROUND

Matrix metalloproteinases (MMPs) are essential for extracellular matrix remodelling and may contribute to the development of endometriosis. Transplantation of endometrium onto the chicken chorioallantoic membrane (CAM) results in endometriosis-like lesion formation, a process that requires extensive tissue remodelling. We investigated the expression of a wide range of MMPs in menstrual endometrium, endometriosis-like lesions in CAMs, in peritoneal endometriosis and in endometriosis in the rectovaginal space, as well as the function of MMPs in early lesion formation in the CAM model.

METHODS

Expression of MMPs was evaluated by immunohistochemistry and MMP function was studied in the CAM by inhibiting MMP activity during lesion formation.

RESULTS

Nearly all MMPs were present in all tissues studied. No significant differences in the expression of a majority of MMPs were found in endometriosis-like lesions in CAMs when compared with human endometriosis. Inhibition of MMP-1, -2, -3, -7 and -13 activities significantly impaired endometriosis-like lesion formation in CAMs.

CONCLUSIONS

The MMP expression profiles of experimentally induced endometriosis in CAMs and human endometriosis are similar. The prevention of endometriosis-like lesion formation in the CAM by inhibiting MMP activity strongly suggests that MMPs have a function in the early development of endometriotic lesions.

Pathogenesis of endometriosis

Many women harbour spots of peritoneal endometriosis without having any symptoms; this is referred to as the phenomenon endometriosis. Some of these women go on to develop symptomatic endometriosis. Although we know the factors potentially involved in the aetiology and pathogenesis of endometriosis, the exact mechanism by which the phenomenon endometriosis develops into the disease endometriosis, with its associated signs and symptoms, remain obscure. The widely accepted theory is Sampson's transplantation theory. Recent findings indicate that certain properties of the endometrium, and the influence of the local environment, are crucial in the development of endometriosis. Early endometriosis lesion formation is described in detail, as this seems to be a key process in the development of peritoneal endometriosis.

Efficacy of anti-tumor necrosis factor therapy in the treatment of spontaneous endometriosis in baboons

OBJECTIVE

To determine the efficacy of anti-tumor necrosis factor therapy (etanercept) for treating endometriosis in baboons.

DESIGN

A randomized, placebo-controlled, blinded study using the baboon endometriosis model.

SETTING

Southwest National Primate Research Center.

ANIMAL(S)

Twelve female baboons with spontaneous peritoneal endometriosis.

INTERVENTION(S)

Etanercept (n = 8) or sterile water (n = 4) was administered subcutaneously three times per week.

MAIN OUTCOME MEASURE(S)

After 8 weeks, the number, color, and surface area of peritoneal lesions was evaluated. Revised American Society for Reproductive Medicine staging was used.

RESULT(S)

A statistically significant decrease in red lesion surface area in the treatment group was observed. A trend toward a decrease in the absolute number of red lesions was noted in the treatment group. White and black lesion number and total surface area slightly increased in both groups but failed to achieve statistical significance. Endometriosis was diagnosed in 60% of captive-born baboons with primary infertility.

CONCLUSION(S)

These results indicate that etanercept effectively reduces the amount of spontaneously occurring active endometriosis in the baboon.

The role of the matrix metalloproteinases in human endometrial and ovarian cycles

The matrix metalloproteinases (MMPs) are part of an expanded family of proteins called the astacin family of zinc metalloproteinases. The MMPs, probably balanced by their tissue inhibitors of metalloproteinases (TIMPs), are essential effectors of developmental processes participating in cell migration, cell proliferation, apoptosis and tissue morphogenesis. The MMPs regulate the function of biologically active molecules as well as fulfilling an important role in endothelial cell invasion, angiogenesis and in tumor progression. The dynamic normal physiology of the human reproductive system involves almost all of the above-mentioned aspects of MMPs activity. This review presents and discusses new insights into the role of MMPs, and their TIMPs, in human endometrial cycle and ovarian function.

Steroid receptor and aromatase expression in baboon endometriotic lesions

OBJECTIVE

To evaluate steroid receptor and aromatase gene expression in endometriotic lesions, and determine the effects of endometriosis on uterine receptivity in a baboon model for endometriosis.

DESIGN

Prospective study to determine the expression of steroid receptors, and aromatase in ectopic endometriotic lesions and endometrial genes in the eutopic endometrium of baboons with induced endometriosis by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunocytochemistry.

SETTING

University research laboratory and primate research facility.

ANIMAL(S)

Normally cycling baboons inoculated intraperitoneally with menstrual endometrium to induce endometriosis.

INTERVENTION(S)

Endometriotic lesions were resected during laparotomy, and endometrium was obtained by endometrectomy or after hysterectomy.

MAIN OUTCOME MEASURE(S)

Steroid receptor and aromatase expression by RT-PCR and immunocytochemistry in endometriotic lesions and glycodelin and alpha-smooth muscle actin expression and localization in endometrium after chorionic gonadotropin (CG) stimulation.

RESULT(S)

This study demonstrated that estrogen receptor-alpha (ERalpha) and progesterone receptor (PR) were expressed in both ectopic and eutopic endometrium between 1 and 10 months after inoculation. In contrast, ERbeta was only expressed in the ectopic endometriotic lesions. Aromatase expression was only evident in lesions obtained 10 months after inoculation. Infusion of CG during the luteal phase failed to induce the expression of glycodelin in the glandular epithelium or alpha-smooth muscle actin (alpha-SMA) in stromal cells in animals with endometriosis as early as 1 and 4 months after inoculation.

CONCLUSION(S)

The ERbeta expression is selectively up-regulated in the endometriotic lesions at all stages of the disease, whereas aromatase expression is not evident until the disease progresses. However, expression of uterine receptivity markers was down-regulated as early as 1 and 4 months after inoculation.