Extracellular matrix metalloproteinase inducer regulates metalloproteinases in human uterine endometrium

S100A8 and S100A9 are associated with endometrial shedding during menstruation

Matrix metalloproteinases (MMPs) and their major source, endometrial stromal cells (ESCs), play important roles in menstruation. However, other mechanisms in endometrial shedding may be unexplored. This study focused on four proteins: S100A8 and S100A9 (alarmins) are binding partners and induce MMPs, MMP-3 cycle-dependently plays a key role in the proteolytic cascade, and CD147, which has S100A9 as its ligand, induces MMPs. Immunostaining for these proteins was performed on 118 resected specimens. The percentage and location of each positive reaction in ESCs were measured and compared using Image J. The influence of leukocytes on S100A8 or S100A9 immunopositivity was also examined. From the premenstrual phase, S100A8 and MMP-3 began to have overlapping expressions in ESCs of the superficial layer, and ESC detachment was found within these sites. S100A9 was expressed from the late secretory phase and CD147 already from earlier. Later, the expression sites of S100A9 and CD147 included those of S100A8. Before menstruation, S100A8 or S100A9 expression was not affected by leukocytes. These results suggest that the local formation of S100A8/S100A9 complex, which occurs specifically in ESCs upon progesterone withdrawal, induces the local expression of MMP-3 and serves as a switch to the lysis phase.

Cyclophilin B serum levels present variations across the menstrual cycle

Cyclophilins are a family of chaperones involved in inflammation and cell death. Cyclophilin B is released by inflammatory cells and acts through the receptor CD147, affecting matrix metalloproteases release, whilst cyclophilin D participates in hypoxia-induced apoptosis. Previous studies related hormones like estradiol or prolactin to these proteins, however, their blood concentrations across the menstrual cycle have not been determined. In this work, eleven healthy women (BMI: 21.8 kg/m2) were monitored during a single menstrual cycle, making blood extractions at follicular, periovulatory and mid-luteal phases. Hormone and cyclophilin levels were determined in each phase. Statistical differences were determined by repeated measures ANOVA and estimated marginal means tests, or by Friedman and Dunn-Bonferroni tests for parametric and non-parametric variables, respectively. Bivariate correlations were evaluated with the Spearman coefficient. Cyclophilin B concentrations presented significant differences during the menstrual cycle (p = 0.012). The highest levels of this protein were found at follicular extraction, followed by a decrease at periovulatory phase and a slight increase at mid-luteal phase. Cyclophilin D showed the same profile, although statistical significance was not reached. This immunophilin exhibited a positive correlation with luteinizing hormone at periovulatory phase (r = 0.743, p = 0.009) and with follicle stimulating hormone at mid-luteal phase (r = 0.633, p = 0.036). This is the first study describing the changes in cyclophilin B concentrations across the menstrual cycle, as well as the association of luteinizing and follicle stimulating hormones with cyclophilin D. These results suggest a role of these proteins in the cyclic inflammatory events that affect female reproductive system that should be explored.

Basigin is necessary for normal decidualization of human uterine stromal cells

STUDY QUESTION

Does basigin (BSG) regulate human endometrial stromal cell (HESC) decidualization in vitro?

SUMMARY ANSWER

BSG regulates HESCs proliferation and decidualization.

WHAT IS KNOWN ALREADY

Studies have shown that in the human endometrium, BSG expression is menstrual-cycle dependent and its expression was significantly lower in uterine endometrium during the luteal phase of women experiencing multiple implantation failures after IVF than in women with normal fertility.

STUDY DESIGN, SIZE, DURATION

We utilized a telomerase-immortalized HESCs in an in vitro cell culture model system to investigate whether BSG regulates decidualization of stromal cells. Further, we used microarray analysis to identify changes in the gene expression profile of HESCs treated with BSG small interfering RNA (siRNA). All experiments were repeated at least three times.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effect of BSG knockdown (using siRNA) on HESC proliferation was determined by counting cell number and by tritiated thymidine incorporation assays. The effect of BSG on decidualization of HESCs was determined by RT-qPCR for the decidualization markers insulin-like growth factor-binding protein 1 (IGFBP1) and prolactin (PRL). Immunoblotting was used to determine the effect of BSG siRNA on the expression of MMP-2,3. Microarray analysis was used to identify BSG-regulated genes in HESCs at Day 6 of decidualization. Functional and pathway enrichment analyses were then carried out on the differentially expressed genes (DEGs). The STRING online database was used to analyze protein-protein interaction (PPI) between DEG-encoded proteins, and CytoScape software was used to visualize the interaction. MCODE and CytoHubba were used to construct functional modules and screen hub genes separately. Several BSG-regulated genes identified in the microarray analysis were confirmed by qPCR.

MAIN RESULTS AND THE ROLE OF CHANCE

Knockdown of BSG expression in cultured stromal cells by siRNA significantly (P < 0.05) inhibited HESC proliferation, disrupted cell decidualization and down-regulated MMP-2 and MMP-3 expression. Microarray analysis identified 721 genes that were down-regulated, and 484 genes up-regulated with P < 0.05 in BSG siRNA treated HESCs. GO term enrichment analysis showed that the DEGs were significantly enriched in cell communication, signaling transduction and regulation, response to stimulus, cell adhesion, anatomical structure morphogenesis, extracellular matrix organization, as well as other functional pathways. KEGG pathway analysis identified upregulated gene enriched in pathways such as the MAPK signaling pathway, colorectal cancer, melanoma and axon guidance. In contrast, downregulated genes were mainly enriched in pathways including ECM-receptor interaction, PI3K-Akt signaling pathway, pathways in cancer, antigen processing, type I diabetes mellitus and focal adhesion. The top 10 hub nodes were identified using 12 methods analyses. The hub genes that showed up in two methods were screened out. Among these genes, upregulated genes included EGFR, HSP90AA1, CCND1, PXN, PRKACB, MGAT4A, EVA1A, LGALS1, STC2, HSPA4; downregulated genes included WNT4/5, FOXO1, CDK1, PIK3R1, IGF1, JAK2, LAMB1, ITGAV, HGF, MXRA8, TMEM132A, UBE2C, QSOX1, ERBB2, GNB4, HSP90B1, LAMB2, LAMC1 and ITGA1. Hub genes and module genes involved in the top three modules of PPI analysis were analyzed through the string database. Analysis showed that hub and module genes were related mainly to the WNT signaling pathway, PI3K-AKT signaling pathway and pathways in cancer.

LARGE SCALE DATA

The microarray data set generated in this study has been published online at databank.illinois.edu.

LIMITATIONS, REASONS FOR CAUTION

Most of the findings were obtained using an in vitro cell culture system that may not necessarily reflect in vivo functions.

WIDER IMPLICATIONS OF THE FINDINGS

Our results demonstrate that BSG plays a vital role in decidualization and that downregulation of BSG in the uterine endometrium may be associated with infertility in women. The identified hub genes and pathways increase our understanding of the genetic etiology and molecular mechanisms underlying the regulation of decidualization by BSG.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the NIH U54 HD40093 (R.A.N.). The authors have no competing interests to declare.

Adenomyosis is associated with specific proton nuclear magnetic resonance (1H-NMR) serum metabolic profiles

OBJECTIVE

To determine whether the adenomyosis phenotype affects the proton nuclear magnetic resonance (¹H-NMR)-based serum metabolic profile of patients.

DESIGN

Cohort study.

SETTING

University hospital-based research center.

PATIENTS

Seventy-seven patients who underwent laparoscopy for a benign gynecologic condition.

INTERVENTIONS

Pelvic magnetic resonance imaging and collection of a venous peripheral blood sample were performed during the preoperative workup. The women were allocated to the adenomyosis group (n = 32), or the control group (n = 45). The adenomyosis group was further subdivided into two groups: diffuse adenomyosis of the inner myometrium (n = 14) and focal adenomyosis of the outer myometrium (n = 18). Other adenomyosis phenotypes were excluded.

MAIN OUTCOME MEASURES

Metabolomic profiling based on ¹H-NMR spectroscopy in combination with statistical approaches.

RESULTS

The serum metabolic profiles of the patients with adenomyosis indicated lower concentrations of 3-hydroxybutyrate, glutamate, and serine compared with controls. Conversely, the concentrations of proline, choline, citrate, 2-hydroxybutyrate, and creatinine were higher in the adenomyosis group. The focal adenomyosis of the outer myometrium and the diffuse adenomyosis phenotypes also each exhibited a specific metabolic profile.

CONCLUSION

Serum metabolic changes were detected in women with features of adenomyosis compared with their disease-free counterparts, and a number of specific metabolic pathways appear to be engaged according to the adenomyosis phenotype. The metabolites with altered levels are particularly involved in immune activation as well as cell proliferation and cell migration. Nevertheless, this study did find evidence of a correlation between metabolite levels and symptoms thought to be related to adenomyosis. Further studies are required to determine the clinical significance of these differences in metabolic profiles.

Blockade of Macrophage CD147 Protects Against Foam Cell Formation in Atherosclerosis

The persistence of macrophage-derived foam cells in the artery wall fuels atherosclerosis development. However, the mechanism of foam cell formation regulation remains elusive. We are committed to determining the role that CD147 might play in macrophage foam cell formation during atherosclerosis. In this study, we found that CD147 expression was primarily increased in mouse and human atherosclerotic lesions that were rich in macrophages and could be upregulated by ox-LDL. High-throughput compound screening indicated that ox-LDL-induced CD147 upregulation in macrophages was achieved through PI3K/Akt/mTOR signaling. Genetic deletion of macrophage CD147 protected against foam cell formation by impeding cholesterol uptake, probably through the scavenger receptor CD36. The opposite effect was observed in primary macrophages isolated from macrophage-specific CD147-overexpressing mice. Moreover, bioinformatics results indicated that CD147 suppression might exert an atheroprotective effect via various processes, such as cholesterol biosynthetic and metabolic processes, LDL and plasma lipoprotein clearance, and decreased platelet aggregation and collagen degradation. Our findings identify CD147 as a potential target for prevention and treatment of atherosclerosis in the future.

Alteration of systemic and uterine endometrial immune populations in patients with endometriosis

PROBLEM

Endometriosis is defined as growth of endometrial tissue in ectopic locations; it is associated with infertility and chronic pain and affects ~12% of reproductive-aged women. Although inflammation is known to play a key role in endometriosis, knowledge related to immune phenotypes associated with this disease is lacking. This study aimed to characterize immune profiles in patients with endometriosis, to assess inflammatory mediators, to and determine if surgical and/or hormonal therapies restore immune homeostasis.

METHODS OF STUDY

Samples from nine controls and 20 histologically confirmed endometriosis patients were collected upon surgery and ~1-3 weeks post-surgical intervention. Subjects were either not utilizing hormonal suppression or were currently on monophasic hormonal therapy. Tolerant regulatory T cells (Tregs = natural [nTregs] +inducible [iTregs]) and inflammatory T helper 17 (Th17) cells were identified in peripheral blood via flow cytometry and within the eutopic/ectopic endometrial tissues via immunohistochemistry and real-time-qPCR. Cytokines were assessed via 10-plex-ELISA.

RESULTS

Patients with endometriosis not utilizing hormonal therapy exhibited lower iTregs (tolerant), greater Th17 (inflammatory), and a reduction in Treg/Th17 ratio (P < .05), indicative of systemic inflammation. Treg and Th17 localizations were enhanced within the ectopic endometrial implant, which promotes lesion development. Hormonal therapy decreased systemic and local inflammation (eutopic/ectopic endometrium) via decreased iTregs and Th17 cells in patients with endometriosis (P < .05). Thus, imbalance within immune populations correlated with increased inflammation in patients with endometriosis, which was mitigated by hormonal therapy.

CONCLUSIONS

Patients with endometriosis exhibited systemic and localized inflammation within ectopic and endometrial tissues. Hormonal therapy dampened inflammation caused by disease.

Development of A 3D Tissue Slice Culture Model for the Study of Human Endometrial Repair and Regeneration

The human endometrium undergoes sequential phases of shedding of the upper functionalis zone during menstruation, followed by regeneration of the functionalis zone from the remaining basalis zone cells, and secretory differentiation under the influence of the ovarian steroid hormones estradiol (E2) and progesterone (P4). This massive tissue regeneration after menstruation is believed to arise from endometrial stromal and epithelial stem cells residing in the basal layer of the endometrium. Although many endometrial pathologies are thought to be associated with defects in these stem cells, studies on their identification and regulation are limited, primarily due to lack of easily accessible animal models, as these processes are unique to primates. Here we describe a robust new method to study endometrial regeneration and differentiation processes using human endometrial tissue slice cultures incorporating an air-liquid interface into a 3D matrix scaffold of type I collagen gel, allowing sustained tissue viability over three weeks. The 3D collagen gel-embedded endometrial tissue slices in a double-dish culture system responded to ovarian steroid hormones, mimicking the endometrial changes that occur in vivo during the menstrual cycle. These changes included the E2-induced upregulation of Ki-67, estrogen receptor (ER), and progesterone receptor (PR) in all endometrial compartments and were markedly suppressed by both P4 and E2 plus P4 treatments. There were also distinct changes in endometrial morphology after E2 and P4 treatments, including subnuclear vacuolation and luminal secretions in glands as well as decidualization of stromal cells, typical characteristics of a progestational endometrium in vivo. This long-term slice culture method provides a unique in vivo-like microenvironment for the study of human endometrial functions and remodeling during early pregnancy and experiments on stem cell populations involved in endometrial regeneration and remodeling. Furthermore, this model has the potential to enable studies on several endometrial diseases, including endometrial cancers and pregnancy complications associated with defects in endometrial remodeling.

Effect of proinflammatory cytokines on endometrial collagen and metallopeptidase expression during the course of equine endometrosis

Equine endometrosis (endometrial fibrosis) is a degenerative chronic process that occurs in the uterus of the mare and disturbs proper endometrial function. Fibrosis is attributed to excessive deposition of extracellular matrix (ECM) components. The turnover of ECM is mediated by matrix metallopeptidases (MMP). Previously, it was shown that cytokines modulate MMP expression in other tissues and may regulate fibrosis indirectly by attracting inflammatory cells to the site of inflammation and directly on various tissues. However, the regulation of MMP expression in equine endometrosis is still relatively unknown. Thus, our aim was to determine if interleukin (IL)-1β and IL-6 regulate ECM, MMPs, or their inhibitors (TIMPs) and whether this regulation differs during endometrosis in the mare. Endometrial fibrosis was divided into four categories according to severity: I (no degenerative changes), IIA (mild degenerative changes), IIB (moderate degenerative changes) and III (severe degenerative changes) according to Kenney and Doig classification. Endometrial explants (n = 5 for category I, IIA, IIB and III according to Kenney and Doig) were incubated with IL-1β (10 ng/ml) or IL-6 (10 ng/ml) for 24 h. Secretion and mRNA transcription of collagen type 1 (Col1a1) and type 3 (Col3a1), fibronectin (Fn1), Mmp-1, -2, -3, -9, -13, Timp-1, -2 were analyzed by real-time PCR and ELISA, respectively. IL-1β treatment up-regulated secretion of COL1, MMP-2, TIMP1, and TIMP2 in category I endometrial fibrosis tissues (P < 0.05). IL-6 treatment up-regulated secretion of ECM, MMP-2, and MMP-3 and down-regulated secretion of MMP-9 in category I tissues (P < 0.05). In category IIA tissues, IL-1β and IL-6 treatment up-regulated secretion of COL3 (P < 0.05; P < 0.05), and IL-6 treatment also down-regulated secretion of MMP-9 (P < 0.05). In category IIB tissues, IL-1β treatment down-regulated secretion of COL3 (P < 0.05) and up-regulated secretion of MMP-3 (P < 0.01), while IL-6 treatment up-regulated secretion of MMP-3, MMP-9, and MMP-13 (P < 0.05). In category III tissues, IL-1β treatment up-regulated secretion of COL1, MMP-1, MMP-9 and TIMP-2 (P < 0.05), and IL-6 up-regulated secretion of all investigated ECM components, MMPs and TIMPs. These results reveal that the effect of IL-1β and IL-6 on equine endometrium differs depending on the severity of endometrial fibrosis. Our findings indicate an association between inflammation and development of endometrosis through the effect of IL-1β and IL-6 on expression of ECM components, MMPs, and TIMPs in the mare.

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.

How, with whom and when: an overview of CD147-mediated regulatory networks influencing matrix metalloproteinase activity

Matrix metalloproteinases (MMPs) comprise a family of 23 zinc-dependent enzymes involved in various pathologic and physiologic processes. In cancer, MMPs contribute to processes from tumour initiation to establishment of distant metastases. Complex signalling and protein transport networks regulate MMP synthesis, cell surface presentation and release. Earlier attempts to disrupt MMP activity in patients have proven to be intolerable and with underwhelming clinical efficacy; thus targeting ancillary proteins that regulate MMP activity may be a useful therapeutic approach. Extracellular matrix metalloproteinase inducer (EMMPRIN) was originally characterized as a factor present on lung cancer cells, which stimulated collagenase (MMP-1) production in fibroblasts. Subsequent studies demonstrated that EMMPRIN was identical with several other protein factors, including basigin (Bsg), all of which are now commonly termed CD147. CD147 modulates the synthesis and activity of soluble and membrane-bound [membrane-type MMPs (MT-MMPs)] in various contexts via homophilic/heterophilic cell interactions, vesicular shedding or cell-autonomous processes. CD147 also participates in inflammation, nutrient and drug transporter activity, microbial pathology and developmental processes. Despite the hundreds of manuscripts demonstrating CD147-mediated MMP regulation, the molecular underpinnings governing this process have not been fully elucidated. The present review summarizes our present knowledge of the complex regulatory systems influencing CD147 biology and provides a framework to understand how CD147 may influence MMP activity.

Up-regulation of Bcl-2 by CD147 Through ERK Activation Results in Abnormal Cell Survival in Human Endometriosis

CONTEXT

Human endometriosis (EMS) is characterized by insufficient apoptosis. Our previous studies have shown elevated CD147 expression in human endometriotic tissues and its involvement in endometrial cell apoptosis. However, the exact underlying mechanism remains elusive.

OBJECTIVE

The objective was to examine the correlation of the highly expressed CD147 with anti-apoptotic factor Bcl-2 in human endometriotic tissues and to determine the CD147-regulated apoptotic pathway in human endometrial epithelial cell line (HES).

DESIGN

This was a laboratory study using human tissue analysis and HES cell culture.

SETTING

The setting was an academic research center and hospital.

PATIENTS

Patients were 30 women with ovarian EMS and 12 women without EMS.

INTERVENTIONS

mRNA levels of CD147 and Bcl-2 were evaluated in endometriotic tissues by quantitative real-time PCR. HES cells were transfected with pcDNA3.0-CD147 overexpressing plasmid or immune-depleted by CD147 antibody.

MAIN OUTCOME MEASURES

Main outcome measures were reverse transcription, quantitative real-time PCR, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, and Western blotting.

RESULTS

In human endometriotic tissues, Bcl-2 was up-regulated and positively correlated with CD147 expression, accompanied by activated ERK signaling. In HES cells, overexpression of CD147 increased viable cells and up-regulated Bcl-2 expression by activation of ERK signaling. Interference with CD147 function suppressed ERK signaling and decreased Bcl-2 expression, followed by accumulation of apoptotic factors, including cleaved caspase-9, cleaved caspase-3, and cleaved poly ADP-ribose polymerase.

CONCLUSIONS

The presently found strong correlations between Bcl-2 and CD147, ERK, and CD147 in human endometriotic lesions and the demonstrated reduced cell apoptosis through CD147-ERK-Bcl-2 intrinsic apoptosis signaling axis suggest that this CD147-regulated signaling may contribute to the enhanced cell survival in the progression of human EMS.

Dynamic contrast-enhanced MRI evaluates the early response of human head and neck tumor xenografts following anti-EMMPRIN therapy with cisplatin or irradiation

PURPOSE

To assess the early therapeutic effects of anti-EMMPRIN (extracellular matrix metalloprotease inducer) antibody with/without cisplatin or X-ray radiation in head and neck cancer mouse models using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

MATERIALS AND METHODS

Mice bearing SCC1 (or OSC19) tumor xenografts were treated with anti-EMMPRIN antibody, radiation, cisplatin, or anti-EMMPRIN antibody plus cisplatin (or radiation) for a week (n = 4-5 per group). DCE-MRI was carried out on a 9.4T small animal MR scanner on days 0, 3, and 7, and K(trans) values were averaged in a 0.5-mm-thick peripheral tumor region. Ki67 and CD31 staining were implemented for all tumors after imaging.

RESULTS

The K(trans) changes of SCC1 and OSC19 tumors treated with anti-EMMPRIN antibody for 3 days were -18 ± 8% and 4 ± 7%, respectively, which were significantly lower than those of control groups (39 ± 5% and 45 ± 7%; P = 0.0025 and 0.0220, respectively). When cisplatin was added, those were -42 ± 9% and -44 ± 9%, respectively, and with radiation, -45 ± 9% and -27 ± 10%, respectively, which were also significantly lower than those of control groups (P < 0.0001 for all four comparisons). In the eight groups untreated (served as control) or treated with anti-EMMPRIN antibody with/without cisplatin or radiation, the mean K(trans) change for 3 days was significantly correlated with the mean tumor volume change for 7 days (r = 0.74, P = 0.0346), Ki67-expressing cell density (r = 0.96, P = 0.0001), and CD31 density (r = 0.84, P = 0.0084).

CONCLUSION

DCE-MRI might be utilized to assess the early therapeutic effects of anti-EMMPRIN antibody with/without chemotherapy or radiotherapy in head and neck cancer.

Elevated hyaluronan and extracellular matrix metalloproteinase inducer levels in women with preeclampsia

PURPOSE

Preeclampsia (PE) is a specific syndrome of pregnancy clinically identified by hypertension and proteinuria from the 20th week of gestation associated with a systemic inflammatory response and oxidative stress. While pro-inflammatory cytokines have been extensively studied in PE, other factors in the circulation that also influence the magnitude of inflammation have received much less attention. The present study compared serum concentrations of five immune-regulatory compounds in normotensive pregnant women and in women with gestational hypertension (GH) or PE.

METHODS

Sixty women with PE, 53 with GH and 40 normotensive women paired by gestational age were evaluated. Sera were evaluated for concentrations of extracellular matrix metalloproteinase inducer (EMMPRIN), hyaluronan, gelsolin, visfatin and histone 2B by ELISA. Differences between groups were analyzed by nonparametric tests, with a significance level of 5%.

RESULTS

Increased levels of EMMPRIN and hyaluronan were present in preeclamptic women as compared to the GH and normotensive groups. There was no difference between groups in gelsolin, visfatin or histone 2B.

CONCLUSION

Increased release of EMMPRIN and hyaluronan may contribute to an elevated pro-inflammatory response and tissue damage in women with PE.

Influence of vaginal bacteria and D- and L-lactic acid isomers on vaginal extracellular matrix metalloproteinase inducer: implications for protection against upper genital tract infections

We evaluated levels of vaginal extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP-8) in vaginal secretions in relation to the composition of vaginal bacterial communities and d- and l-lactic acid levels. The composition of vaginal bacterial communities in 46 women was determined by pyrosequencing the V1 to V3 region of 16S rRNA genes. Lactobacilli were dominant in 71.3% of the women, followed by Gardnerella (17.4%), Streptococcus (8.7%), and Enterococcus (2.2%). Of the lactobacillus-dominated communities, 51.5% were dominated by Lactobacillus crispatus, 36.4% by Lactobacillus iners, and 6.1% each by Lactobacillus gasseri and Lactobacillus jensenii. Concentrations of l-lactic acid were slightly higher in lactobacillus-dominated vaginal samples, but most differences were not statistically significant. d-Lactic acid levels were higher in samples containing L. crispatus than in those with L. iners (P < 0.0001) or Gardnerella (P = 0.0002). The relative proportion of d-lactic acid in vaginal communities dominated by species of lactobacilli was in concordance with the proportions found in axenic cultures of the various species grown in vitro. Levels of l-lactic acid (P < 0.0001) and the ratio of l-lactic acid to d-lactic acid (P = 0.0060), but not concentrations of d-lactic acid, were also correlated with EMMPRIN concentrations. Moreover, vaginal concentrations of EMMPRIN and MMP-8 levels were highly correlated (P < 0.0001). Taken together, the data suggest the relative proportion of l- to d-lactic acid isomers in the vagina may influence the extent of local EMMPRIN production and subsequent induction of MMP-8. The expression of these proteins may help determine the ability of bacteria to transverse the cervix and initiate upper genital tract infections.

A large proportion of preterm births (>50%) result from infections caused by bacteria originating in the vagina, which requires that they traverse the cervix. Factors that influence susceptibility to these infections are not well understood; however, there is evidence that matrix metalloproteinase (MMP-8) is known to alter the integrity of the cervix. In this work, we show that concentrations of vaginal extracellular matrix metalloproteinase inducer (EMMPRIN) are influenced by members of the vaginal microbial community and concentrations of d- or l-lactic acid isomers in vaginal secretions. Elevated levels of d-lactic acid and the ratio of d- to l-lactic acid influence EMMPRIN concentrations as well as MMP-8 levels. Thus, isomers of lactic acid may function as signaling molecules that alter host gene expression and influence risk of infection-related preterm birth.

Antagonistic effects of anti-EMMPRIN antibody when combined with chemotherapy against hypovascular pancreatic cancers

PURPOSE

To examine the antagonistic effects of anti-extracellular matrix metalloprotease inducer (anti-EMMPRIN) antibody when combined with chemotherapy using a hypovascular pancreatic tumor model.

PROCEDURES

Severely compromised immunodeficient mice bearing orthotopic MIA PaCa-2 tumors were used (five to six animals per group). Dynamic contrast-enhanced magnetic resonance imaging was used to examine the relationship between tumor vascularity and size. Therapy was initiated when tumors were hypovascular. Treatments included: (1) gemcitabine alone, (2) anti-EMMPRIN antibody alone, and (3) combination, each for 2 weeks. Additionally, another treatment arm included β-lapachone, an NAD(P)H/quinone 1 (NQO1) bioactivated agent. (18)F-fluoro-D-glucose-positron emission tomography/computed tomography imaging was used weekly to monitor therapeutic effects.

RESULTS

Gemcitabine or anti-EMMPRIN monotherapy significantly delayed tumor growth, but the combination therapy showed an antagonistic effect. Similarly, tumor growth was significantly suppressed by β-lapachone alone, and additive effects were noted when combined with gemcitabine, but the therapeutic efficacy was reduced when anti-EMMPRIN antibody was added.

CONCLUSIONS

Anti-EMMPRIN antibody with chemotherapy in hypovascular tumors results in antagonistic effects.

Altered cytokine gene expression in peripheral blood monocytes across the menstrual cycle in primary dysmenorrhea: a case-control study

Primary dysmenorrhea is one of the most common gynecological complaints in young women, but potential peripheral immunologic features underlying this condition remain undefined. In this paper, we compared 84 common cytokine gene expression profiles of peripheral blood mononuclear cells (PBMCs) from six primary dysmenorrheic young women and three unaffected controls on the seventh day before (secretory phase), and the first (menstrual phase) and the fifth (regenerative phase) days of menstruation, using a real-time PCR array assay combined with pattern recognition and gene function annotation methods. Comparisons between dysmenorrhea and normal control groups identified 11 (nine increased and two decreased), 14 (five increased and nine decreased), and 15 (seven increased and eight decreased) genes with ≥2-fold difference in expression (P<0.05) in the three phases of menstruation, respectively. In the menstrual phase, genes encoding pro-inflammatory cytokines (IL1B, TNF, IL6, and IL8) were up-regulated, and genes encoding TGF-β superfamily members (BMP4, BMP6, GDF5, GDF11, LEFTY2, NODAL, and MSTN) were down-regulated. Functional annotation revealed an excessive inflammatory response and insufficient TGF-β superfamily member signals with anti-inflammatory consequences, which may directly contribute to menstrual pain. In the secretory and regenerative phases, increased expression of pro-inflammatory cytokines and decreased expression of growth factors were also observed. These factors may be involved in the regulation of decidualization, endometrium breakdown and repair, and indirectly exacerbate primary dysmenorrhea. This first study of cytokine gene expression profiles in PBMCs from young primary dysmenorrheic women demonstrates a shift in the balance between expression patterns of pro-inflammatory cytokines and TGF-β superfamily members across the whole menstrual cycle, underlying the peripheral immunologic features of primary dysmenorrhea.

Stimulation of GPR30 increases release of EMMPRIN-containing microvesicles in human uterine epithelial cells

CONTEXT

Uterine remodeling is highly dependent on the glycosylated transmembrane protein extracellular matrix metalloproteinase (MMP) inducer (EMMPRIN). Previous studies indicate estradiol can increase EMMPRIN expression in uterine cells and promote subsequent induction of MMP production.

OBJECTIVE

The aim of this study was to investigate the role of G protein-coupled receptor 30 (GPR30) stimulation on EMMPRIN microvesicle release in the human uterine epithelial cell line hTERT-EEC (EECs).

DESIGN

We examined EMMPRIN release by human EECs in response to GPR30 stimulation by microvesicle isolation, Western blot, and immunocytochemistry. We employed a pharmacological approach using the GPR30-selective agonist G1 and the antagonist G15 to determine the receptor specificity of this response.

RESULTS

We demonstrated GPR30 expression in EECs and release of EMMPRIN in microvesicles in response to stimulation of GPR30. G1, estradiol, and cholera toxin stimulated EMMPRIN release in microvesicles as detected by Western blot and immunocytochemistry, indicating that stimulation of GPR30 can induce EMMPRIN microvesicle release.

CONCLUSIONS

These data indicate that EMMPRIN release in microvesicles can be mediated by stimulation of GPR30 in human EECs, suggesting that inappropriate stimulation or expression of this receptor may be significant in uterine pathology.

The efficacy of bevacizumab, sorafenib, and retinoic acid on rat endometriosis model

Blood vessels are necessary for development and maintenance of the endometriosis and blood flow supplies oxygen and essential nutrient to the disease. Local angiogenesis is regulated by vascular endothelial growth factor (VEGF) and inhibitors of VEGF may be a novel therapeutic approach. We inducted endometriosis in 43 rats and they were randomly allocated into 4 groups. The rats in group I (control n = 11) were given no medication. The rats in group II (n = 11) were given bevacizumab. The rats in group III (n = 11) were given Sorafenib, and the rats in group IV (n = 10) were given retinoic acid (RA). Then groups were compared for microvessel density, VEGF, soluble tyrosine-kinase receptor, ovarian reserve, and treatment effectivity. All these medications were effective on endometriosis and we detected that volume of endometriotic implants were significantly decreased. Ovarian reserve was not affected from the medication, in addition RA have induced reproductive capacity.

EMMPRIN is secreted by human uterine epithelial cells in microvesicles and stimulates metalloproteinase production by human uterine fibroblast cells

Endometrial remodeling is a physiological process involved in the gynecological disease, endometriosis. Tissue remodeling is directed by uterine fibroblast production of matrix metalloproteinases (MMPs). Several MMPs are regulated directly by the protein extracellular matrix metalloproteinase inducer (EMMPRIN) and also by proinflammatory cytokines such as interleukin (IL)1-α/β. We hypothesized that human uterine epithelial cells (HESs) secrete intact EMMPRIN to stimulate MMPs. Microvesicles from HES cell-conditioned medium (CM) expressed intact EMMPRIN protein. Treatment of HES cells with estradiol or phorbyl 12-myristate-13-acetate increased the release of EMMPRIN-containing microvesicles. The HES CM stimulated MMP-1, -2, and -3 messenger RNA levels in human uterine fibroblasts (HUFs) and EMMPRIN immunodepletion from HES-cell concentrated CM reduced MMP stimulation (P < .05). Treatment of HUF cells with low concentrations of IL-1β/α stimulated MMP production (P < .05). These results indicate that HES cells regulate MMP production by HUF cells by secretion of EMMPRIN, in response to ovarian hormones, proinflammatory cytokines as well as activation of protein kinase C.

Extracelluar matrix metalloproteinase as a novel target for pancreatic cancer therapy

The objective of this study was to evaluate extracellular matrix metalloproteinase (EMMPRIN) as a novel target in orthotopic pancreatic cancer murine models. MIA PaCa-2 human pancreatic tumor cells were implanted in groups 1 and 3-7, whereas MIA PaCa-2 EMMPRIN knockdown cells were implanted in group 2. Dosing with anti-EMMPRIN antibody started immediately after implantation for groups 1-3 (residual tumor model) and at 21 days after cell implantation for groups 4-7 (established tumor model). Groups 3, 5, and 7 were treated with anti-EMMRPIN antibody (0.2-1.0 mg) twice weekly for 2-3 weeks, whereas the other groups served as the control. In the residual tumor model, tumor growth of anti-EMMPRIN-treated group was successfully arrested for 21 days (15 ± 4 mm(3)), which was significantly lower than that of the EMMPRIN knockdown group (80 ± 15 mm(3); P=0.001) or the control group (240 ± 41 mm(3); P<0.001). In the established tumor model, anti-EMMPRIN therapy lowered tumor volume increase by approximately 40% compared with the control, regardless of the dose amount. Ki67-expressed cell density of group 5 was 939 ± 150 mm(-2), which was significantly lower than that of group 4 (1709 ± 145 mm(-2); P=0.006). Microvessel density of group 5 (30 ± 6 mm(-2)) was also significantly lower than that of group 4 (53 ± 5 mm(-2); P=0.014), whereas the microvessel size of group 5 (191 ± 22 μm(2)) was significantly larger than that of group 4 (113 ± 26 μm(2); P=0.049). These data show the high potential of anti-EMMPRIN therapy for pancreatic cancer and support its clinical translation.

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.

Dual combination therapy targeting DR5 and EMMPRIN in pancreatic adenocarcinoma

The goal of the study was to assess the efficacy of combined extracellular matrix metalloprotease inducer (EMMPRIN)- and death receptor 5 (DR5)-targeted therapy for pancreatic adenocarcinoma in orthotopic mouse models with multimodal imaging. Cytotoxicity of anti-EMMPRIN antibody and anti-DR5 antibody (TRA-8) in MIA PaCa-2 and PANC-1 cell lines was measured by ATPlite assay in vitro. The distributions of Cy5.5-labeled TRA-8 and Cy3-labeled anti-EMMPRIN antibody in the 2 cell lines were analyzed by fluorescence imaging in vitro. Groups 1 to 12 of severe combined immunodeficient mice bearing orthotopic MIA PaCa-2 (groups 1-8) or PANC-1 (groups 9-12) tumors were used for in vivo studies. Dynamic contrast-enhanced-MRI was applied in group 1 (untreated) or group 2 (anti-EMMPRIN antibody). The tumor uptake of Tc-99m-labeled TRA-8 was measured in group 3 (untreated) and group 4 (anti-EMMPRIN antibody). Positron emission tomography/computed tomography imaging with (18)F-FDG was applied in groups 5 to 12. Groups 5 to 8 (or groups 9 to 12) were untreated or treated with anti-EMMPRIN antibody, TRA-8, and combination, respectively. TRA-8 showed high killing efficacy for both MIA PaCa-2 and PANC-1 cells in vitro, but additional anti-EMMPRIN treatment did not improve the cytotoxicity. Cy5.5-TRA-8 formed cellular caps in both the cell lines, whereas the maximum signal intensity was correlated with TRA-8 cytotoxicity. Anti-EMMPRIN therapy significantly enhanced the tumor delivery of the MR contrast agent, but not Tc-99m-TRA-8. Tumor growth was significantly suppressed by the combination therapy, and the additive effect of the combination was shown in both MIA PaCa-2 and PANC-1 tumor models.

Regulation of matrix metalloproteinases activity studied in human endometrium as a paradigm of cyclic tissue breakdown and regeneration

When abundant and activated, matrix metalloproteinases (MMPs, or matrixins) degrade most, if not all, constituents of the extracellular matrix (ECM). The resulting massive tissue breakdown is best exemplified in humans by the menstrual lysis and shedding of the endometrium, the mucosa lining the uterus. After menstruation, MMP activity needs to be tightly controlled as the endometrium regenerates and differentiates to avoid abnormal tissue breakdown while allowing tissue repair and fine remodelling to accommodate implantation of a blastocyst. This paper reviews how MMPs are massively present and activated in the endometrium at menstruation, and how their activity is tightly controlled at other phases of the cycle. Progesterone represses expression of many but not all MMPs. Its withdrawal triggers focal expression of MMPs specifically in the areas undergoing lysis, an effect mediated by local cytokines such as interleukin-1α, LEFTY-2, tumour necrosis factor-α and others. MMP-3 is selectively expressed at that time and activates proMMP-9, otherwise present in latent form throughout the cycle. In addition, a large number of neutrophils loaded with MMPs are recruited at menstruation through induction of chemokines, such as interleukin-8. At the secretory phase, progesterone repression of MMPs is mediated by transforming growth factor-β. Tissue inhibitors of metalloproteinases (TIMPs) are abundant at all phases of the cycle to prevent any undue MMP activity, but are likely overwhelmed at menstruation. At other phases of the cycle, MMPs can elude TIMP inhibition as exemplified by recruitment of active MMP-7 to the plasma membrane of epithelial cells, allowing processing of membrane-associated growth factors needed for epithelial repair and proliferation. Finally, receptor-mediated endocytosis through low density lipoprotein receptor-related protein-1 (LRP-1) efficiently clears MMP-2 and -9 at the proliferative and secretory phases. This mechanism is probably essential to prevent any excessive ECM degradation by the active form of MMP-2 that is permanently present. However, shedding of the ectodomain of LRP-1 specifically at menstruation prevents endocytosis of MMPs allowing full degradation of the ECM. Thus endometrial MMPs are regulated at the levels of transcription, release from infiltrating neutrophils, activation, binding to the cell membrane, inhibition by TIMPs and endocytic clearance by LRP-1. This allows tight control during endometrial growth and differentiation but results in a burst of activity for menstrual tissue breakdown. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.

Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits invasion of human immortalized endometriotic epithelial and stromal cells through suppression of metalloproteinases

Prostaglandin E2 (PGE2) plays an important role in the pathogenesis of endometriosis. We recently reported that inhibition of COX-2 decreased migration as well as invasion of human endometriotic epithelial and stromal cells. Results of the present study indicates that selective inhibition of PGE2 receptors EP2 and EP4 suppresses expression and/or activity of MMP1, MMP2, MMP3, MMP7 and MMP9 proteins and increases expression of TIMP1, TIMP2, TIMP3, and TIMP4 proteins and thereby decreases migration and invasion of human immortalized endometriotic epithelial and stromal cells into matrigel. The interactions between EP2/EP4 and MMPs are mediated through Src and β-arrestin 1 protein complex involving MT1-MMP and EMMPRIN in human endometriotic cells. These novel findings provide an important molecular and cellular framework for further evaluation of selective inhibition of EP2 and EP4 as potential nonsteroidal therapy for endometriosis in childbearing-age women.

Epidermal growth factor (EGF) induces motility and upregulates MMP-9 and TIMP-1 in bovine trophoblast cells

Differentiation and restricted invasion/migration of trophoblast cells are crucial for feto-maternal communication in the synepitheliochorial placenta of cattle. EGF is expressed in the bovine placenta and likely regulates these cell properties. As cell migration and motility rely on the degradation of extracellular matrix we hypothesize that EGF is involved in the regulation of the MMP-9/TIMP-1 balance and thus could influence trophoblast migration, tissue remodeling, and the release of the fetal membranes after parturition. The aim of this in vitro study was to examine EGF-mediated effects on cell motility, proliferation, and MMP-9 and TIMP-1 expression in cultured bovine trophoblast cells. We used a trophoblast cell line (F3) derived from bovine placentomes to examine the influence of EGF on MMP-9 and TIMP-1 expression by semiquantitative RT-PCR and MMP activity by zymography. Migration assays were performed using a Boyden chamber and cell motility was measured by time-lapse analyses. To identify the involved signaling cascades, phosphorylation of mitogen-activated protein kinase (MAPK) 42/44 and Akt was detected by Western blot. EGF treatment increased both the abundance of MMP-9 and TIMP-1 mRNAs and the proteolytic activity of MMP-9. Furthermore, EGF stimulated proliferation and migration of F3 cells. Addition of specific inhibitors of MAPK (PD98059) and/or PI3K (LY294002) activation abolished or reduced EGF-induced effects in all experiments. In conclusion, EGF-mediated effects stimulate migration and proliferation of bovine trophoblast cells and may be involved in bovine placental tissue remodeling and postpartum release of fetal membranes.

Extracellular matrix metalloproteinase inducer expression in the baboon endometrium: menstrual cycle and endometriosis

Extracellular matrix metalloproteinase inducer (EMMPRIN; BSG) regulates tissue remodeling through matrix metalloproteinases (MMPs). In human and non-human primates, endometrial remodeling is important for menstruation and the pathogenesis of endometriosis. We hypothesized that as in humans, BSG and MMPs are expressed in the endometrium of cycling baboons, and their expression is hormonally regulated by ovarian hormones, but endometriosis disrupts this regulation. BSG expression was evaluated in the baboon endometrium by q-PCR and immunohistochemistry. In the endometrium of control cycling animals, BSG mRNA levels were highest in late secretory stage tissue. BSG protein localized to glandular epithelial cells during the proliferative phase; whereas, secretory stage tissues expressed BSG in glandular and luminal epithelia with weak stromal staining. Several MMPs were differentially expressed throughout the menstrual cycle with the highest levels found during menstruation. In ovariectomized animals, BSG endometrial mRNA levels were highest with treatment of both estrogen and progesterone than that with only estrogen. Estrogen alone resulted in BSG protein localization primarily in the endometrial glandular epithelia, while estrogen and progesterone treatment displayed BSG protein localization in both the glandular and stromal cells. Exogenous hormone treatment resulted in differential expression patterns of all MMPs compared with the control cycling animals. In the eutopic endometrium of endometriotic animals, BSG mRNA levels and protein were elevated early but decreased later in disease progression. Endometriosis elevated the expression of all MMPs except MMP7 compared with the control animals. In baboons, BSG and MMP endometrial expression is regulated by both ovarian hormones, and their expression patterns are dysregulated in endometriotic animals.

Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its related extracellular matrix degrading enzymes in the endometrium during estrous cycle and early gestation in cattle

BACKGROUND

Extracellular matrix metalloproteinase inducer (EMMPRIN) regulates several biological functions involving the modulation of cell behaviors via cell-cell and cell-matrix interactions. According to its diverse functions, we hypothesized that EMMPRIN may play an important role in endometrial remodeling and establishment of pregnancy in cow.

METHODS

In this study, endometrial tissues from the cyclic cows during before ovulation, after ovulation and middle of estrous cycle; and pregnant endometrial tissues from Day 19 to 35 of gestation have been used. Expression of mRNA was analyzed by RT-PCR, qPCR and in situ hybridization whereas protein expression by immunohistochemistry and western blot analysis.

RESULTS

EMMPRIN mRNA was expressed in both cyclic and pregnant endometrium and significantly higher in the endometrium at Day 35 of gestation than the cyclic endometrium. In Western blot analysis, an approximately 65 kDa band was detected in the endometrium, and approximately 51 kDa in the cultured bovine epithelial cells and BT-1 cells, respectively. Both in situ hybridization and immunohistochemistry data showed that EMMPRIN was primarily expressed in luminal and glandular epithelium with strong staining on Day 19 conceptus. At Day 19 of gestation, expression of EMMPRIN mRNA on luminal epithelium was decreased than that observed at middle of estrous cycle, however, on Day 30 of gestation, slightly increased expression was found at the site of placentation. Expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 mRNA were mainly detected in stroma and their expression also decreased at Day 19 of gestation however it was also expressed at the site of placentation at Day 30 of gestation as observed for EMMPRIN. Expression of MMP-1 or -9 mRNA was very low and was below the detection limit in the cyclic and pregnant endometrium.

CONCLUSION

EMMPRIN from the luminal epithelium may regulate the expression of stromal MMP-2 and -14 suggesting its crucial role in adhesion and fusion of embryo to luminal epithelium by directly itself through physiological tissues remodeling and developmental process, and/or stimulating MMPs to compensate endometrial functions.

Anti-EMMPRIN monoclonal antibody as a novel agent for therapy of head and neck cancer

PURPOSE

Extracellular matrix metalloprotease inducer (EMMPRIN) is a tumor surface protein that promotes growth and is overexpressed in head and neck cancer. These features make it a potential therapeutic target for monoclonal antibody (mAb)-based therapy. Because molecular therapy is considered more effective when delivered with conventional cytotoxic agents, anti-EMMPRIN therapy was assessed alone and in combination with external beam radiation.

EXPERIMENTAL DESIGN

Using a murine flank model, loss of EMMPRIN function was achieved by transfection with a small interfering RNA against EMMPRIN or treatment with a chimeric anti-EMMPRIN blocking mAb. Cytokine expression was assessed for xenografts, tumor cells, fibroblasts, and endothelial cells.

RESULTS

Animals treated with anti-EMMPRIN mAb had delayed tumor growth compared with untreated controls, whereas treatment with combination radiation and anti-EMMPRIN mAb showed the greatest reduction in tumor growth (P = 0.001). Radiation-treated EMMPRIN knockdown xenografts showed a reduction in tumor growth compared with untreated knockdown controls (P = 0.01), whereas radiation-treated EMMPRIN-expressing xenografts did not show a delay in tumor growth. Immunohistochemical evaluation for Ki67 and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) resulted in a reduction in proliferation (P = 0.007) and increased apoptosis in anti-EMMPRIN mAb-treated xenografts compared with untreated controls (P = 0.087). In addition, we provide evidence that EMMPRIN suppression results in decreased interleukin 1beta (IL-1beta), IL-6, and IL-8 cytokine production, in vitro and in vivo.

CONCLUSIONS

These data suggest that anti-EMMPRIN antibody inhibits tumor cell proliferation in vivo and may represent a novel targeted treatment option in head and neck squamous cell carcinoma.

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.

The role of matrix metalloproteinases in the pathogenesis of endometriosis

Endometriosis is a benign, estrogen-dependent disease with an obscure etiology. Even the most widely accepted theory of retrograde menstruation cannot satisfactorily explain the development of endometriosis due to the many gaps in our understanding of its pathophysiology. Although most women have retrograde menstruation; only some develop endometriosis. Apart from simply being present in the peritoneal cavity, the endometrial cells are able to attach to, invade the peritoneum, and proliferate to create and maintain an endometriotic lesion. Matrix metalloproteinases (MMPs) are a group of enzymes that degrade the extracellular matrix. These enzymes participate in the histologic changes of the endometrium during the menstrual cycle with generally a higher expression during the menstrual and proliferative phase of the endometrium and a decreased expression during the secretory phase. As noted above, not only do these enzymes play a crucial factor in the cycling endometrium but the degradation of extracellular matrix is essential for the endometrial cells to invade the peritoneum and to develop an endometriotic lesion as well. The aim of this review is to describe the altered expression of MMPs in the development of endometriosis.

Basigin-mediated gene expression changes in mouse uterine stromal cells during implantation

Implantation of mouse embryos is dependent on the proliferation and differentiation of uterine stromal cells in a process called decidualization. Decidualization both supports and limits the invasion of the implanting embryo and is regulated in part by the expression of matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). Molecules that alter the balance between MMP and TIMP expression could prevent implantation of the embryo. The membrane glycoprotein basigin (CD147/EMMPRIN), a known inducer of MMPs, is necessary for normal implantation in the mouse. The purpose of this study was to investigate the potential roles of basigin during implantation in the mouse. Using an in vitro stromal cell culture system, we found that recombinant human basigin protein (rBSG) increases MMP-3 and MMP-9 expression without altering TIMP-3 expression. Our results also showed rBSG induces expression of cytokines IL-1alpha/beta and leukocyte chemoattractants, CCL3, CCL20, CXCL2, and CXCL5. More importantly, rBSG significantly suppressed stromal cell decidualization as shown by the inhibition of alkaline phosphatase-2 expression and activity by rBSG. However, rBSG did not affect stromal cell proliferation. Taken together, our data indicate that basigin mediates gene expression changes in mouse uterine stromal cells and suggests that temporal and spatial regulation of basigin expression may be involved in the recruitment of leukocytes to the mouse uterus during early pregnancy.

EMMPRIN expression is required for response to bevacizumab therapy in HNSCC xenografts

The HNSCC cell line, FaDu was stably transfected with control vector (FaDu) or with plasmid expressing small interfering RNA against EMMPRIN (FaDu/siE). Tumor cells were treated with bevacizumab (0, 25, 50, and 75 ng/ml) in vitro, and then cell counts were performed at 72 h. For in vivo analysis, tumor cells were xenografted onto the flank of SCID mice, and were treated with 100 microg bevacizumab twice weekly for three weeks. Xenograft samples from the control and treatment groups were analyzed for microvessel density. Escalating doses of bevacizumab had no effect on the growth of tumor cells in vitro (P.or=0.086). However, tumor xenografts expressing EMMPRIN responded to bevacizumab treatment (P=0.0013), whereas the EMMPRIN knockdown cell line did not (P=0.7942). Immunohistochemical analysis demonstrated that microvascular density was reduced in the treated FaDu tumors (P=0.005), but not in the FaDu/siE tumors (P=0.48). Currently there is limited information on biomarkers to predict response to bevacizumab. By demonstrating effectiveness of bevacizumab therapy in tumors that express EMMPRIN, but not in tumors with silenced EMMPRIN expression, this study suggests that EMMPRIN may serve as a biomarker for response to bevacizumab treatment.

The altered distribution of the steroid hormone receptors and the chaperone immunophilin FKBP52 in a baboon model of endometriosis is associated with progesterone resistance during the window of uterine receptivity

This study examines the distribution of estrogen receptors (ESR), progesterone receptors (Pgr), and the chaperone immunophilin FKBP52 in the eutopic endometrium in a baboon model of endometriosis during the window of receptivity to determine if their aberrant distribution contributes to reduced fecundity. Endometriosis was induced by inoculation of menstrual endometrium into the peritoneal cavity. Eutopic endometrium was collected at 3, 6, 9, 12, and 15 months postinoculation. Western blot (WB) and immunohistochemical analyses were performed. Isolated endometrial stromal cells were cultured in the presence or absence of steroid hormones. In animals with endometriosis, ESR-1 (ER-alpha) decreased in endometrial stromal cells, while ESR-2 (ER-beta) was reduced in both glandular epithelial (GE) and stromal cells. Immunoreactive total Pgr was markedly diminished in the GE, which was confirmed by WB analysis. Furthermore, treatment of isolated stromal cells from baboons with endometriosis with hormones did not increase levels of PRA or PRB as in control baboons. FKBP52 was also reduced in the eutopic endometrium of baboons with endometriosis. Endometriosis results in an aberrant distribution of ESR-1, ESR-2, Pgr, and FKBP52 in the eutopic endometrium. The authors propose that a dysregulation in the paracrine signaling between the endometrial stromal and GE cells reduces the responsiveness of Pgr, creating an endometrial environment that is unsuitable for implantation.

Cytokines regulate matrix metalloproteinases in human uterine endometrial fibroblast cells through a mechanism that does not involve increases in extracellular matrix metalloproteinase inducer

PROBLEM

Endometriosis is the presence of ectopic uterine endometrial tissue in the peritoneal cavity. Peritoneal fluid samples of women with endometriosis show elevated interleukin-1 (IL-1)beta, tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta(1) levels, indicating that an altered immune system may play an important role in the pathogenesis of endometriosis. The invasion of ectopic endometrium into peritoneal mesothelium requires matrix metalloproteinases (MMPs) for tissue remodeling. Several MMPs are differentially expressed in human uterine endometrium with menstrual endometrium showing the highest level of expression. MMPs are stimulated by cytokines and also by the protein Extracellular Matrix Metalloproteinase Inducer (EMMPRIN).

METHOD OF STUDY

To determine the role of cytokines in ectopic endometrial invasion, we investigated whether cytokines could regulate MMP production by endometrial fibroblast cells and whether this stimulation occurred through an effect on EMMPRIN expression. Human uterine fibroblasts (HUF) were treated with IL-1beta, TGF-beta(1) and TNF-alpha in a dose dependent and time dependent manner (C, 0.1, 1, 10 ng/mL IL-1beta or TGF-beta(1); C, 2, 10, 50 ng/mL TNF-alpha) for 0, 6, 12, and 24 hr. Cell conditioned medium samples were collected and concentrated at each timepoint for immunoblot analysis. Cellular RNA was collected for real time PCR analysis of MMPs-1, -2, -3 and EMMPRIN mRNA levels.

RESULTS

Our results showed that IL-1beta stimulated MMP-1 protein secretion and mRNA levels in a time dependent manner (P < 0.05), MMP-2 mRNA in a time dependent manner and MMP-3 in a time and dose dependent manner. TNF-alpha stimulated MMP-1 and -3 protein secretion in a time dependent manner and stimulated MMP-1, -2 and -3 mRNA levels in a time dependent manner (P < 0.05). Neither IL-1beta nor TNF-alpha treatment affected MMP-2 protein secretion. TGF-beta(1) inhibited MMP-1 and MMP-2 mRNAs at the highest treatment dose after 24 hr but there was no effect on protein secretion. TGF-beta(1) exerted no effect on MMP-3 mRNA or protein secretion (P < 0.05). Neither of the cytokines affected EMMPRIN protein or mRNA levels but the 10 ng/mL TGF-beta(1) treatment did cause a reduction in EMMPRIN mRNA levels.

CONCLUSIONS

These data show that elevated cytokines may play a role in the establishment of ectopic endometrium in the peritoneal cavity by stimulating MMPs to remodel the mesothelial lining of the peritoneum thus allowing for tissue invasion. The stimulation of MMPs by cytokines occurred without any change in EMMPRIN expression whereas the inhibitory effect of TGF-beta(1) involved a reduction in EMMPRIN mRNA levels.