Macrophage migration inhibitory factor antagonist blocks the development of endometriosis in vivo

Targeting inflammation for the treatment of endometritis in bovines

The uterine endometrial surface of bovines is in constant exposureconstantly exposed with to a multitude ofmany microbial populations that changes throughout the post-partum phase in terms of complexity and dynamics. These microbes contribute to the host pathology, leading to severe economic losses along withnd reproductive capabilities. The basic primary interface that occurs between the internal tissues of the body of the hostbetween the host body's internal tissues and the microbes is the endometrial surface of the uterus. As a result of the infinite pathogenic population, there is always a danger for the opportunistic organisms to attack. Therefore, it is paramount that any interactions, especially microbial microbes with the endometrial surface, are regulated by the host cells. However, the inflammatory response as the defense mechanism contributes a pivotal roleis pivotal in host immunity and pathology. The inflammatory cascade and pathways are important essential to eliminate this clinical problem. In this review, we will discuss and explain how the inflammation and the various components of the immune system play their role in host pathology and therapeutic strategies, taking into account the interface between the host and the microbes on the surface of the endometrium. This review is also instrumental in further explanation of inflammatory uterine disease by discussing the response of inflammation to external insult.

Dissecting the miR-451a-Mif Pathway in Endometriosis Pathophysiology Using a Syngeneic Mouse Model: Temporal Expression of Lesion Mif Receptors, Cd74 and Cxcr4

Endometriosis is an enigmatic disease characterized by pain and infertility in which endometrial tissue grows in ectopic locations, predominantly the pelvic cavity. The pathogenesis and pathophysiology of endometriosis is complex and postulated to involve alterations in inflammatory, cell proliferation and post-transcriptional regulatory pathways among others. Our understanding on the pathogenesis and pathophysiology of endometriosis is further complicated by the fact that endometriosis can only be diagnosed by laparoscopy only after the disease has manifested. This makes it difficult to understand the true pathogenesis as a cause-and-effect relationship is difficult to ascertain. To aid in our understanding on endometriosis pathogenesis and pathophysiology, numerous rodent models have been developed. In this case, we discuss further assessment of a miR-451a-macrophage migration inhibitory factor (Mif) pathway which contributes to lesion survival. Specifically, we evaluate the temporal expression of lesion Mif receptors, Cd74 and Cxcr4 using host mice which express wild-type or miR-451a deficient lesions. Similar to that observed in humans and a non-human primate model of endometriosis, Cd74 expression is elevated in lesion tissue in a temporal fashion while that of Cxcr4 shows minimal increase during initial lesion establishment but is reduced later during the lifespan. Absence of miR-451a during initial lesion establishment is associated with an augmentation of Cd74, but no Cxcr4 expression. The data obtained in this study provide further support for a role of Mif receptors, Cd74 and Cxcr4 in the pathophysiology of endometriosis.

Endometriosis-Associated Angiogenesis and Anti-angiogenic Therapy for Endometriosis

Endometriosis is a known estrogen-dependent inflammatory disease affecting reproductive-aged women. Common symptoms include pelvic pain, dysmenorrhea, dyspareunia, heavy menstrual bleeding, and infertility. The exact etiology of endometriosis is largely unknown, and, thus, the diagnosis and treatment of endometriosis are challenging. A complex interplay of many molecular mechanisms is thought to aid in the progression of endometriosis, most notably angiogenesis. This mini-review examines our current knowledge of the molecular etiology of endometriosis-associated angiogenesis and discusses anti-angiogenic therapy, in the blockade of endometriosis-associated angiogenesis, as potential non-hormonal therapy for the treatment of endometriosis.

Macrophage migration inhibitory factor promotes the migration of dendritic cells through CD74 and the activation of the Src/PI3K/myosin II pathway

Constitutively expressed by innate immune cells, the cytokine macrophage migration inhibitory factor (MIF) initiates host immune responses and drives pathogenic responses in infectious, inflammatory, and autoimmune diseases. Dendritic cells (DCs) express high levels of MIF, but the role of MIF in DC function remains poorly characterized. As migration is critical for DC immune surveillance, we investigated whether MIF promoted the migration of DCs. In classical transwell experiments, MIF^-/- bone marrow-derived DCs (BMDCs) or MIF^+/+ BMDCs treated with ISO-1, an inhibitor of MIF, showed markedly reduced spontaneous migration and chemotaxis. CD74^-/- BMDCs that are deficient in the ligand-binding component of the cognate MIF receptor exhibited a migration defect similar to that of MIF^-/- BMDCs. Adoptive transfer experiments of LPS-matured MIF^+/+ and MIF^-/- and of CD74^+/+ and CD74^-/- BMDCs injected into the hind footpads of homologous or heterologous mice showed that the autocrine and paracrine MIF activity acting via CD74 contributed to the recruitment of DCs to the draining lymph nodes. Mechanistically, MIF activated the Src/PI3K signaling pathway and myosin II complexes, which were required for the migration of BMDCs. Altogether, these data show that the cytokine MIF exerts chemokine-like activity for DC motility and trafficking.

Protective effect of ISO-1 with inhibition of RIPK3 up-regulation and neutrophilic accumulation on acetaminophen-induced liver injury in mice

Overdose use of acetaminophen (APAP) often occurs a severe liver injury, and its liver injury is lethal in some cases. Macrophage migration inhibitory factor (MIF) is expressed in a variety of cells and has multifunctional roles. However, the role of MIF in APAP-induced liver injury has not been fully investigated. In this study, we investigated whether treatment with (S,R)-3-(4-hydroxyphenil)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), a MIF inhibitor, protected mice from acute APAP-induced liver injury. Acute liver injury was induced by injection of APAP (300 mg/kg body weight). Mice were treated with a single injection of ISO-1(15 mg/kg body weight) 1 h (h) before APAP administration. Histological, biochemical and molecular analyses were performed in liver of mice 12 h after APAP administration. ISO-1 remarkably improved the histological findings of APAP-induced liver injury in mice. The increases in serum levels of alanine aminotransferase (ALT), and macrophage inflammatory protein-2 (MIP-2) by APAP were inhibited by ISO-1. In addition, ISO-1 reduced the increased number of the myeloperoxidase-staining cells and that of TUNEL-positive staining cells in the liver of mice with APAP-induced liver injury. Up-regulation of hepatic receptor interacting protein kinase (RIPK)3 and heat shock protein70 by APAP was suppressed in the liver of mice given ISO-1. These results provide the additional evidence that inhibition of MIF activity may be clinically effective for treatment of acute APAP-induced liver injury.

Macrophage migration inhibitory factor modulates cytokine expression in the trophoblast cell line HTR-8/SVneo

Extravillous trophoblasts are specific placental cells that invade the uterine stroma and spiral arteries modifying and adjusting them to pregnancy. Many pregnancy pathologies are associated with impairment of this process, including preeclampsia and intrauterine growth restriction, among others. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that is abundant at the fetomaternal interface. Previous results from our group showed that MIF participates in trophoblast invasion and modulates the expression of molecules known to mediate stromal and endovascular trophoblast invasion. In this study we investigated the possibility that MIF could act as a regulator of cytokines known to modulate trophoblast invasion using the normal extravillous trophoblast-derived cell line HTR-8/SVneo. Expression of trophoblast MIF was attenuated by MIF mRNA-specific small interfering RNAs. Cytokine expression was assessed at the mRNA and protein levels using real-time quantitative polymerase chain reaction and flow cytometry respectively. Knockdown of MIF led to a significant decrease in mRNA for IL-1β (IL1B) and IL-8 (CXCL8) and interleukin (IL)-8 protein. The addition of recombinant human MIF to cell culture medium increased IL-6 after 24h treatment and IL-6 and IL-8 after 72h treatment. Cell viability was not affected by MIF silencing or rhMIF treatment. The results of this study imply that at least some of the effects of MIF on trophoblast invasion could be mediated through autocrine or paracrine modulation of trophoblast cytokine production.

Aldose Reductase Inhibitor Engeletin Suppresses Pelvic Inflammatory Disease by Blocking the Phospholipase C/Protein Kinase C-Dependent/NF-κB and MAPK Cascades

Pelvic inflammatory disease (PID) is a common inflammation in the upper reproductive tract in women and may cause serious and costly consequences without effective treatment. Engeletin is a flavanonol glycoside and a naturally derived aldose reductase (AR) inhibitor that is widely distributed in vegetables, fruits, and plant-based foods. The present study investigated the anti-PID activity of engeletin in a mucilage-induced rat model of PID and LPS-stimulated RAW 264.7 macrophages. Engeletin significantly reduced inflammation and ameliorated the typical uterine pathological changes in PID rats. Engeletin also inhibited AR-dependent PLC/PKC/NF-κB and MAPK inflammatory pathways, as indicated by the suppression of the phosphorylation levels of PLC, PKC, p38, ERK, and JNK and the nuclear translocation of NF-κB p65. In vitro studies demonstrated that engeletin significantly inhibited inflammatory mediator expression and enhanced the phagocytic ability of LPS-induced RAW 264.7 macrophages. RNA interference of AR prevented the engeletin-induced inhibition of inflammatory mediators. Engeletin also inhibited AR-dependent PLC/PKC/NF-κB and MAPK inflammatory pathways, which was consistent with the in vivo results. These findings support engeletin as a potential agent for prevention or treatment of PID.

Amine oxidase 3 is a novel pro-inflammatory marker of oxidative stress in peritoneal endometriosis lesions

Endometriosis is a common gynaecological disease of women in reproductive age, and is thought to arise from retrograde menstruation and implantation of endometrial tissue, mostly into the peritoneal cavity. The condition is characterized by a chronic, unresolved inflammatory process thereby contributing to pain as cardinal symptom in endometriosis. Elevated reactive oxygen species (ROS) and oxidative stress have been postulated as factors in endometriosis pathogenesis. We here set out for a systematic study to identify novel mechanisms and pathways relating to oxidative stress in ectopic peritoneal lesions. Using combined proteomic and transcriptomic approaches, we identified novel targets including upregulated pro-oxidative enzymes, such as amine oxidase 3/vascular adhesion protein 1 (AOC3/VAP1) as well as downregulated protective factors, in particular alkenal reductase PTGR1 and methionine sulfoxide reductase. Consistent with an altered ROS landscape, we observed hemoglobin / iron overload, ROS production and lipid peroxidation in ectopic lesions. ROS-derived 4-hydroxy-2-nonenal induced interleukin IL-8 release from monocytes. Notably, AOC3 inhibitors provoked analgesic effects in inflammatory pain models in vivo, suggesting potential translational applicability.

Roles of macrophage migration inhibitory factor in Guillain-Barré syndrome and experimental autoimmune neuritis: beneficial or harmful?

INTRODUCTION

Macrophage migration inhibitory factor (MIF) plays an important role in the pathogenesis of Guillain-Barré syndrome (GBS) and its animal model experimental autoimmune neuritis (EAN), which may offer an opportunity for the development of the novel therapeutic strategies for GBS. Areas covered: 'macrophage migration inhibitory factor' and 'Guillain-Barré syndrome' were used as keywords to search for related publications on Pub-Med, National Center for Biotechnology Information (NCBI), USA. MIF is involved in the etiology of various inflammatory and autoimmune disorders. However, the roles of MIF in GBS and EAN have not been summarized in the publications we identified. Therefore, in this review, we described and analyzed the major roles of MIF in GBS/EAN. Primarily, this molecule aggravates the inflammatory responses in this disorder. However, multiple studies indicated a protective role of MIF in GBS. The potential of MIF as a therapeutic target in GBS has been recently demonstrated in experimental and clinical studies, although clinical trials have been unavailable to date. Expert opinion: MIF plays a critical role in the initiation and progression of GBS and EAN, and it may represent a potential therapeutic target for GBS.

Transforming growth factor β1 enhances adhesion of endometrial cells to mesothelium by regulating integrin expression

Endometriosis is the abnormal growth of endometrial cells outside the uterus, causing pelvic pain and infertility. Furthermore, adhesion of endometrial tissue fragments to pelvic mesothelium is required for the initial step of endometriosis formation outside uterus. TGF-β1 and adhesion molecules importantly function for adhesion of endometrial tissue fragments to mesothelium outside uterus. However, the function of TGF-β1 on the regulation of adhesion molecule expression for adhesion of endometrial tissue fragments to mesothelium has not been fully elucidated. Interestingly, transforming growth factor β1 (TGF-β1) expression was higher in endome-triotic epithelial cells than in normal endometrial cells. The adhesion efficiency of endometriotic epithelial cells to meso-thelial cells was also higher than that of normal endometrial cells. Moreover, TGF-β1 directly induced the adhesion of endometrial cells to mesothelial cells through the regulation of integrin of αV, α6, β1, and β4 via the activation of the TGF-β1/TGF-βRI/Smad2 signaling pathway. Conversely, the adhesion of TGF-β1-stimulated endometrial cells to mesothelial cells was clearly reduced following treatment with neutralizing antibodies against specific TGF-β1-mediated integrins αV, β1, and β4 on the endometrial cell membrane. Taken together, these results suggest that TGF-β1 may act to promote the initiation of endometriosis by enhancing integrin-mediated cell-cell adhesion.

Macrophage Migration Inhibitory Factor Receptor, CD74, is Overexpressed in Human and Baboon ( Papio Anubis) Endometriotic Lesions and Modulates Endometriotic Epithelial Cell Survival and Interleukin 8 Expression

CD74 is the primary receptor for macrophage migration inhibitory factor (MIF). Although expression of MIF has been described in endometriotic lesions, the cellular localization and function of the MIF receptor, CD74, are poorly understood. To further explore the role of CD74 in the pathophysiology of endometriosis, we utilized specimens from women with diagnostically confirmed endometriosis, women with no signs or symptoms of endometriosis (controls), and 8 baboons with experimentally induced endometriosis. Compared to eutopic endometrium from women with endometriosis, CD74 transcript expression was significantly increased in endometriotic lesion tissue. Similarly, cellular expression of CD74 was significantly greater in ectopic lesion tissue compared to paired eutopic endometrium, which both expressed greater CD74 expression compared to eutopic endometrium from control patients. Localization of CD74 was predominant to epithelial cells of ectopic and matched eutopic endometrium and was not influenced by the stage of the menstrual cycle. Eutopic endometrium from control patients did not express detectable levels of CD74 protein by immunohistochemistry. This pattern of expression and CD74 protein localization could be recapitulated in endometriotic lesion tissue from baboons with experimentally induced disease. Transfection of the endometriotic epithelial cell lines, 12Z with CD74 short hairpin RNA (shRNA), resulted in a significant decrease in CD74 protein expression, which was associated with a significant reduction in cellular proliferation as well as the expression of the prosurvival cytokine interleukin 8. Together, these data support the hypothesis that CD74 is elevated in endometriotic lesion tissue and may contribute to the pathogenesis of endometriosis by promoting cell survival.

Expression of CD74 in bladder cancer and its suppression in association with cancer proliferation, invasion and angiogenesis in HT-1376 cells

The aim of the present study was to investigate the expression and potential roles of CD74 in human urothelial cell carcinoma of the bladder (UCB) in vitro and in vivo. CD74 and macrophage migration inhibitory factor (MIF) were located and assayed in normal and UCB samples and cell lines using immunostaining. CD74 was knocked down using CD74 shRNA lentiviral particles in HT-1376 cells. The proliferative, invasive potential and microvessel density (MVD) of knockdown-CD74 HT-1376 cells were analyzed in vitro or in vivo. The expression of CD74 in an additional high grade UCB J82 cell line was also verified in vivo. All experiments were repeated at least 3 times. The majority of muscle-invasive bladder cancer (MIBC) samples, and only one high grade UCB cell line, HT-1376, expressed CD74, compared with normal, non-muscle-invasive bladder cancer (NMIBC) samples and other cell lines. The levels of proliferation and invasion were decreased in the CD74 knockdown-HT-1376 cells, and western blotting assay indicated that the levels of proteins associated with proliferation, apoptosis and invasion in the cells were affected correspondingly by different treatments in vitro. The tumorigenesis and MVD assays indicated less proliferation and angiogenesis in the knockdown-HT-1376 cells compared with the scramble cells. Notably, J82 cells exhibiting no signal of CD74 in vitro presented the expression of CD74 in vivo. The present study revealed the potential roles of CD74 in the proliferation, invasion and angiogenesis of MIBC, and that it may serve as a potential therapeutic target for UCB, but additional studies are required.

Future Directions in Endometriosis Research and Therapeutics

Background

Endometriosis is a disease common among women of reproductive age characterized by pain, anxiety and infertility. Defined as the growth of endometrial tissue in ectopic locations, endometriosis remains an enigmatic disease for which current treatments are less than ideal. Much of these shortcomings to current therapy stem from our incomplete understanding on the pathogenesis of the disease. It is generally accepted that endometriosis is an estrogen-dependent disease and, as such, the majority of treatment approaches aim at reducing estrogen action and/or production. Unfortunately, this approach is not effective in all women with endometriosis and in those women where success is achieved with their use, there is potential for health-comprising side effects.

Objective

The objective of this review is to summarize current approaches for treatment of endometriosis, discuss their limitations and potential reasons for lack of progress towards better therapeutics for this disease.

Results

In this review we summarize the current approaches for treatment of endometriosis, discuss their limitations and potential reasons for lack of progress towards better therapeutics for this disease.

Conclusion

Based upon the current state of knowledge, there is a strong necessity for through assessment at the level of the genome, miRNAome and proteome as well as the importance of integrating clinically-relevant endpoints in future studies which evaluate potential endometriosis therapies in experimental models of endometriosis.

Cyclic AMP responsive element-binding protein induces metastatic renal cell carcinoma by mediating the expression of matrix metallopeptidase-2/9 and proteins associated with epithelial-mesenchymal transition

Renal cell carcinoma (RCC) is the most frequently occurring malignancy of the kidney worldwide. Anti-angiogenic targeted therapies inhibit the progression of RCC, however, limited effects on the invasion or metastasis of tumor cells have been observed. Cyclic AMP responsive element‑binding protein (CREB) is a serine/threonine kinase that has been implicated in the regulation of cell proliferation, apoptosis, cycle progression and metastasis, amongst others. Our previous research demonstrated that phosphorylated CREB (pCREB) was upregulated in human renal cancer cell lines and tissues, and decreased pCREB at the Ser133 site inhibited the growth and metastatic activity of OS‑RC‑2 cells. However, the role of CREB in RCC metastasis requires further investigation. Thus, the present study further investigated the role of CREB in RCC metastasis. The present study demonstrated that knockdown of CREB using small interfering RNA (siRNA) that targeted CREB (siCREB) significantly inhibited the migration and invasion of 786‑O and OS‑RC‑2 cells, however, the opposite effect was observed in ACHN cells. In addition, knockdown of CREB suppressed the expression of matrix metallopeptidase (MMP)‑2/9 and proteins associated with epithelial‑mesenchymal transition (EMT) in 786‑O and OS‑RC‑2 cells, and promoted expression in ACHN cells. Furthermore, the chromatin immunoprecipitation assay indicated that pCREB (Ser133) had a direct interaction with the fibronectin promoter, however, pCREB (Ser133) did not target the vimentin promoter in RCC. Therefore, the results of the present study indicate that CREB regulated metastatic RCC by mediating the expression of MMP‑2/9 and EMT‑associated proteins, however, CREB‑mediated MMP‑2/9 and EMT‑associated protein expression may be induced by different pathways in different RCC cells.

Regulation of angiogenic factors by the PI3K/Akt pathway in A549 lung cancer cells under hypoxic conditions

The aim of the present study was to investigate the influence of hypoxia and PI3K inhibition on angiogenic factors in A549 lung cancer cells. A549 cells were treated with the PI3K inhibitor LY294002 under normoxic and hypoxic conditions. Untreated cells were used as the control group and those treated by the inhibitor, as the suppression group. The cells were further divided based on normoxic or hypoxic conditions and named: Normoxic control group, normoxic suppression group, hypoxic control group and hypoxic suppression group. Expression levels of hypoxia-inducible factor (HIF)-1α and AKT1 mRNA in all groups were determined by reverse transcriptase-quantitative polymerase chain reaction and concentrations of vascular endothelial growth factor (VEGF), angiotensin II (ANG-II), transforming growth factor (TGF)-α/β1, and tumor necrosis factor (TNF)-α in the culture supernatant were measured by enzyme-linked immunosorbent assay. The expression levels of HIF-1α and AKT1 mRNA in the hypoxic control group were higher than those in the normoxic control group and the expression levels of HIF-1α and AKT1 mRNA in the hypoxic control group were higher than those in the hypoxic suppression group. Compared to the normoxic control and normoxic suppression groups, the concentrations of VEGF and TNF-α in supernatant were higher in the hypoxic control and hypoxic suppression groups, respectively. However, TGF-α and TGF-β1 demonstrated the opposite trend of the aforementioned factors. The concentration of ANG-II in the hypoxic suppression group was higher than that in the normoxic suppression group. In addition, compared to the normoxic control group and hypoxic control group, the concentrations of VEGF and TGF-β1 in supernatant were lower in the normoxic suppression group and in the hypoxic suppression group, respectively. In conclusion, the results of the present study suggest that hypoxia can stimulate A549 lung cancer cells to secrete VEGF and TNF-α and inhibit TGF-α and TGF-β1. The ability of A549 cells to secrete VEGF and TGF-β1 is regulated by PI3K/Akt, and ANG-II expression may be regulated by the PI3K/Akt pathway under hypoxic condition.

Immunosuppressive macrophages induced by IDO1 promote the growth of endometrial stromal cells in endometriosis

It was previously demonstrated that anomalous expression of indoleamine 2,3-dioxygenase-1 (IDO1) in endometrial stromal cells (ESCs) stimulated an inflammatory response that subsequently initiated the activation of immunosuppressive macrophages in endometriosis. The aim of the present study was to clarify the effect of IDO1‑induced macrophages on the growth of ESCs in endometriosis. Normal ESCs, ectopic ESCs and normal ESCs treated with plasmid pEGFP‑N1‑IDO1 or SD11‑IDO1 short hairpin RNA were co‑cultured with peripheral blood‑derived monocyte (PBMC)‑driven macrophages directly for 48 h. Compared with normal ESCs, the PBMC‑driven macrophages that were co‑cultured with ectopic ESCs displayed a lower phagocytic ability. pEGFP‑N1‑IDO1 transfection of normal ESCs also decreased the phagocytic ability of co‑cultured macrophages. Additionally, pEGFP‑N1‑IDO1‑transfected ESC‑induced macrophages significantly increased the viability and proliferation of ESCs, while ESC apoptosis was decreased, compared with control ESCs. In conclusion, IDO1 educated-macrophages may facilitate the survival of retrograde endometrial tissues, and be involved in the pathogenesis of endometriosis.

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

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

Integrative Analysis Reveals Regulatory Programs in Endometriosis

Endometriosis is a common gynecological disease found in approximately 10% of reproductive-age women. Gene expression analysis has been performed to explore alterations in gene expression associated with endometriosis; however, the underlying transcription factors (TFs) governing such expression changes have not been investigated in a systematic way. In this study, we propose a method to integrate gene expression with TF binding data and protein-protein interactions to construct an integrated regulatory network (IRN) for endometriosis. The IRN has shown that the most regulated gene in endometriosis is RUNX1, which is targeted by 14 of 26 TFs also involved in endometriosis. Using 2 published cohorts, GSE7305 (Hover, n = 20) and GSE7307 (Roth, n = 36) from the Gene Expression Omnibus database, we identified a network of TFs, which bind to target genes that are differentially expressed in endometriosis. Enrichment analysis based on the hypergeometric distribution allowed us to predict the TFs involved in endometriosis (n = 40). This included known TFs such as androgen receptor (AR) and critical factors in the pathology of endometriosis, estrogen receptor α, and estrogen receptor β. We also identified several new ones from which we selected FOXA2 and TFAP2C, and their regulation was confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry (IHC). Further, our analysis revealed that the function of AR and p53 in endometriosis is regulated by posttranscriptional changes and not by differential gene expression. Our integrative analysis provides new insights into the regulatory programs involved in endometriosis.

Novel agents for the medical treatment of endometriosis

PURPOSE OF REVIEW

Current medical treatments for endometriosis-associated pain, including oral contraceptives, progestins and GnRH agonists, are partially effective and have significant side-effects. The purpose of this review is to present new hormonal and nonhormonal treatment for endometriosis.

RECENT FINDINGS

At present, the ideal drug that can prevent, inhibit or stop development of endometriosis, reduce associated pain or infertility and allow conception does not exist. New drugs in development for endometriosis modulate GnRH, estrogen and/or progesterone receptors, or target endometriosis-associated inflammation, angiogenesis, adhesion and/or tissue invasion. Most have been tested in rodents, and have been evaluated in more relevant animal models like nonhuman primates (baboons), but only a few, that is GnRH antagonists, have been tested in human randomized controlled trials. Important safety and efficacy issues remain a concern, as steroid receptors, inflammation, adhesion, angiogenesis and tissue invasion are key factors in physiological events like ovulation, menstruation and embryo implantation.

SUMMARY

New drugs for the medical treatment of endometriosis targeting both hormonal (GnRH, estrogen and progesterone receptors) and nonhormonal pathways (inflammation, angiogenesis, adhesions, tissue invasion) are promising, but their efficacy and safety need to be established in randomized human trials before they can be used in clinical practice.

The expression of microRNA-451 in human endometriotic lesions is inversely related to that of macrophage migration inhibitory factor (MIF) and regulates MIF expression and modulation of epithelial cell survival

STUDY QUESTION

What is the role of microRNA-451 (miR-451) in human endometriotic tissue?

SUMMARY ANSWER

miR451 expression was elevated in endometriotic lesion tissue. MiR451 modulated the expression of macrophage migration inhibitory factor and limited cell survival.

WHAT IS KNOWN ALREADY

microRNAs are post-transcriptional regulators of gene expression which have been reported to be mis-expressed in endometriotic tissue. The exact pattern of expression and role of miR451 in endometriosis is currently unknown.

STUDY DESIGN, SIZE, DURATION

Thirty women with endometriosis are included in the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Matched eutopic (N = 30) and endometriotic lesion tissue (N = 43) were collected. miR-451, macrophage migration inhibitory factor (MIF), cyclin E1 (CCNE) and phosphatase and tensin homolog (PTEN) mRNA expression were examined by quantitative real-time (qRT)-PCR while MIF protein expression was evaluated by western blot analysis. miR-451 regulation of MIF in vitro translation was confirmed by 3'untranslated region (UTR) reporter assays and western blot analysis. The effect of miR-451 on cell survival was assessed using a human endometrial epithelial cell line (HES).

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with eutopic endometrium, both MIF mRNA and protein were significantly (P < 0.05) decreased in endometriotic lesions and this was associated with a significant (P < 0.05) increase in miR-451 expression. Transfection of HES cells with luciferase reporter constructs for MIF revealed that miR-451 specifically bound to the 3'UTR to regulate expression. Further, forced expression of miR-451 induced a significant (P < 0.05) down-regulation of both MIF mRNA and protein in HES cells which was associated with a significant (P < 0.05) reduction in cell survival. Inhibition of MIF using a specific antagonist verified that reduction of MIF contributes to HES cell survival.

LIMITATIONS, REASONS FOR CAUTION

miR-451 and MIF expression were only examined in tissue from women with endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

Our data support the hypothesis that miR-451 is elevated in endometriotic tissue and, through regulating MIF expression, may function to limit endometriotic lesion cell survival.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the National Institutes of Health/NICHD by grant NIH HD069043 to W.B.N. The authors have no competing interests.

Urine, peritoneal fluid and omental fat proteomes of reproductive age women: Endometriosis-related changes and associations with endocrine disrupting chemicals

Endometriosis, ectopic growth of the uterine lining (endometrium), which affects 6-11% of reproductive age women, is associated with pelvic pain and infertility. We investigated the peritoneal fluid (PF), urine and omental fat (OF) proteomes of women with endometriosis vs. individuals with no surgically visualized endometriosis. All participants were enrolled in the NICHD-funded ENDO Study. A two-step proteomic study was performed. The first, a broad survey, employed a semi-quantitative gel LC-mass spectrometry (MS) workflow: SDS PAGE fractionation, trypsin digestion and LC-MS/MS. The results showed sample integrity but failed to detect any differences between women with and without endometriosis. The second step was a quantitative analysis of OF samples. We employed another sample set (n=30) from women ± disease and isobaric mass-tag (iTRAQ) chemistry to label peptides and 2D LC-MS/MS for protein identification and quantification. Three proteins-matrix metalloproteinase-9, neutrophil elastase, and FAM49B-were significantly lower in abundance in samples from women with endometriosis. Interestingly, neutrophil elastase and FAM49B levels were associated with higher levels of a subset of endocrine disrupting chemicals (EDCs) that were previously measured in the same samples. The results of these experiments showed the feasibility of associating endometriosis with changes in the OF protein repertoire and EDC levels.

BIOLOGICAL SIGNIFICANCE

Endometriosis, pathological growth of the uterine lining, is associated with significant morbidities, including pain and infertility. However, the causes of this common condition are poorly understood. This study determined whether endometriosis was associated with changes in the protein composition of peritoneal fluid, urine and/or omental fat. A protein of unknown function (FAM49B) and two proteinases (metalloproteinase-9, neutrophil elastase) were down regulated in OF samples from women with versus without endometriosis. These findings suggested proteinase imbalances at sites that were distant from the endometriotic lesions. Additionally, FAM49B and neutrophil elastase levels were associated with higher levels of a subset of environmental chemicals that were quantified in the same samples, suggesting other possible associations. Thus, this work generated hypotheses that will be tested in further studies.

Pharmacological inhibition of MIF interferes with trophoblast cell migration and invasiveness

INTRODUCTION

Macrophage migration inhibitory factor (MIF) is expressed by villous and extravillous cytotrophoblast. This study was aimed to investigate functional relevance of MIF for human trophoblast.

METHODS

MIF mRNA and protein were documented in cytotrophoblast (CT) and extravillous trophoblast cell line HTR-8/SVneo by RT-PCR, Western blot (WB), and immunocytochemistry. Recombinant human MIF (rhMIF), or its specific inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) were used in Wound healing migration and Matrigel invasion tests. Potential effectors, integrin subunits and matrix metalloproteinases (MMP) were studied using WB and gelatin zymography, respectively.

RESULTS

Blocking endogenous MIF by ISO-1 decreased HTR-8/SVneo cell migration dose dependently, most significantly with 200 μg/ml to 65% of control. Supplementation with rhMIF induced a significant stimulation to 129% of control with 200 ng/ml. In CT cell invasion test, ISO-1 at 200 μg/ml reduced invasion to 59% of control, while rhMIF (200 ng/ml) induced stimulation to 159% of control. In HTR-8/SVneo cells, invasion was significantly inhibited by ISO-1 to 40%, and increased to 150% of control by rhMIF (200 ng/ml). Integrin α1 was reduced by ISO-1 in both cell types, while integrins α5 and β1 were not changed. Addition of rhMIF increased integrin α1. In the presence of ISO-1, levels of MMP-2 and MMP-9 were reduced in CT and HTR-8/SVneo, while rhMIF stimulated MMP-2 in CT and MMP-9 in HTR-8/SVneo cells.

CONCLUSION

Reported findings provide the first insight into the cellular effects of MIF in human trophoblast, which acts to promote cell migration and invasion.

Macrophage migration inhibitory factor is involved in ectopic endometrial tissue growth and peritoneal-endometrial tissue interaction in vivo: a plausible link to endometriosis development

Pelvic inflammation is a hallmark of endometriosis pathogenesis and a major cause of the disease's symptoms. Abnormal immune and inflammatory changes may not only contribute to endometriosis-major symptoms, but also contribute to ectopic endometrial tissue growth and endometriosis development. A major pro-inflammatory factors found elevated in peritoneal fluid of women with endometriosis and to be overexpressed in peritoneal fluid macrophages and active, highly vascularized and early stage endometriotic lesions, macrophage migration inhibitory factor (MIF) appeared to induce angiogenic and inflammatory and estrogen producing phenotypes in endometriotic cells in vitro and to be a possible therapeutic target in vivo. Using a mouse model where MIF-knock out (KO) mice received intra-peritoneal injection of endometrial tissue from MIF-KO or syngeneic wild type (WT) mice and vice versa, our current study revealed that MIF genetic depletion resulted in a marked reduction ectopic endometrial tissue growth, a disrupted tissue structure and a significant down regulation of the expression of major inflammatory (cyclooxygenease-2), cell adhesion (αv and β3 integrins), survival (B-cell lymphoma-2) and angiogenic (vascular endothelial cell growth) factorsrelevant to endometriosis pathogenesis, whereas MIF add-back to MIF-KO mice significantly restored endometriosis-like lesions number and size. Interestingly, cross-experiments revealed that MIF presence in both endometrial and peritoneal host tissues is required for ectopic endometrial tissue growth and pointed to its involvement in endometrial-peritoneal interactions. This study provides compelling evidence for the role of MIF in endometriosis development and its possible interest for a targeted treatment of endometriosis.

Effect of vascular formed endothelial cell network on the invasive capacity of melanoma using the in vitro 3D co-culture patterning model

In vitro three dimensional (3D) cancer models were developed to observe the invasive capacity of melanoma cell spheroids co-cultured with the vascular-formed endothelial cell network. An array-like multicellular pattern of mouse melanoma cell line B16F1 was developed by magnetic cell labeling using a pin-holder device for allocation of magnetic force. When the B16F1 patterned together with a vascular network of human umbilical vein epithelial cells (HUVEC), spreading and progression were observed along the HUVEC network. The B16F1 cells over 80 µm distance from HUVEC remain in a compact spheroid shape, while B16F1 in the proximity of HUVEC aggressively changed their morphology and migrated. The mRNA expression levels of IL-6, MDR-1 and MMP-9 in B16F1 increased along with the distance the HUVEC network, and these expressions were increased by 5, 3 and 2-fold in the B16F1 close to HUVEC (within 80 µm distance) as compared to that far from HUVEC (over 80 µm distance). Our results clearly show that malignancy of tumor cells is enhanced in proximity to vascular endothelial cells and leads to intravasation.

Macrophages: are they involved in endometriosis, abortion and preeclampsia and how?

Macrophages hold a key role in both regulating and executing the body's own immune response under various conditions. Hence, although endometriosis, preeclampsia and abortions are clinically different, all three are regarded to involve highly complex immunological processes. The aim of our current work was to evaluate the role of macrophages within these gynaecological disorders. Macrophages have been shown to invade endometriosis lesions and to mediate propagation of endometriotic cyst growth. However this is the first time that significant GPER up-regulation in macrophages is demonstrated. This highlights a potential alternative way through which estrogen may modulate immune response of macrophages in endometriosis. In addition, during spontaneous miscarriages the macrophage population increases significantly. This deregulation may possibly support an inflammatory scheme further triggering abortive procedures. Macrophage-mediated apoptosis of extravillous trophoblasts (EVT) has been associated with preeclampsia. Larger numbers of apoptotic EVT were detected in preeclamptic placentas compared with normal. In preeclamptic placentas, decidual macrophages were found to be Fas ligand (FasL)-positive. Our results highlight a new aspect of macrophage biology in endometriosis and pregnancy physiology and patho-physiology. Further studies with larger samples are needed to verify the current results and evaluate their clinical impact. Our data strongly indicate that macrophages hold key roles in various gynaecological disorders and might be crucial to further elucidate their patho-physiology.

Shikonin reduces endometriosis by inhibiting RANTES secretion and mononuclear macrophage chemotaxis

Endometriosis is a common disease in females of reproductive age and has the classic characteristic of mononuclear cell infiltration into lesions. Shikonin is an anti-inflammatory phytocompound obtained from Lithospermum erythrorhizon whose potential therapeutic effects in the treatment of endometriosis remain unclear. The working hypothesis of the present study was that shikonin is capable of inhibiting the development of endometriosis by inhibiting the chemotactic effect. In a murine model of endometriosis, shikonin significantly inhibited the growth of human endometrial tissue implanted into severe combined immunodeficiency (SCID) mice (P<0.05) and no adverse effects were observed. Mouse regulated upon activation normal T-cell expressed and secreted (mRANTES) levels in the peritoneal fluid of the animal endometriosis model were higher than those in normal SCID mice (P<0.05) and decreased significantly following shikonin treatment in a dose-dependent manner (P<0.05). Peritoneal fluid from SCID mice treated with shikonin inhibited the chemotaxis of monocytes; this inhibitory effect was eradicated by mRANTES antibody. In vitro, shikonin significantly inhibited RANTES expression in U937 cells that were cultured alone or co-cultured with human mesothelial and endometrial stromal cells. In addition, shikonin inhibited the RANTES-induced chemotaxis of U937 cells (P<0.05). The results indicate that shikonin inhibits the development of endometriosis by various mechanisms, including the inhibition of RANTES expression and the reduction of mononuclear cell migration to lesions. Therefore, shikonin may be a novel, useful and safe agent for treating endometriosis.

Interplay between Misplaced Müllerian-Derived Stem Cells and Peritoneal Immune Dysregulation in the Pathogenesis of Endometriosis

In the genetic regulation of Müllerian structures development, a key role is played by Hoxa and Wnt clusters, because they lead the transcription of different genes according to the different phases of the organogenesis, addressing correctly cell-to-cell interactions, allowing, finally, the physiologic morphogenesis. Accumulating evidence is suggesting that dysregulation of Wnt and/or Hox genes may affect cell migration during organogenesis and differentiation of Müllerian structures of the female reproductive tract, with possible dislocation and dissemination of primordial endometrial stem cells in ectopic regions, which have high plasticity to differentiation. We hypothesize that during postpubertal age, under the influence of different stimuli, these misplaced and quiescent ectopic endometrial cells could acquire new phenotype, biological functions, and immunogenicity. So, these kinds of cells may differentiate, specializing in epithelium, glands, and stroma to form a functional ectopic endometrial tissue. This may provoke a breakdown in the peritoneal cavity homeostasis, with the consequent processes of immune alteration, documented by peripheral mononuclear cells recruitment and secretion of inflammatory cytokines in early phases and of angiogenic and fibrogenic cytokines in the late stages of the disease.

Angiogenesis and endometriosis

A comprehensive review was performed to survey the role of angiogenesis in the pathogenesis of endometriosis. This is a multifactorial disease in which the development and maintenance of endometriotic implants depend on their invasive capacity and angiogenic potential. The peritoneal fluid of patients with endometriosis is a complex suspension carrying inflammatory cytokines, growth factors, steroid hormones, proangiogenic factors, macrophages, and endometrial and red blood cells. These cells and their signaling products concur to promote the spreading of new blood vessels at the endometriotic lesions and surroundings, which contributes to the endometriotic implant survival. Experimental studies of several antiangiogenic agents demonstrated the regression of endometriotic lesions by reducing their blood supply. Further studies are necessary before these novel agents can be introduced into clinical practice, in particular the establishment of the safety of anti-angiogenic medications in women who are seeking to become pregnant.

The albino mutation of tyrosinase alters ocular angiogenic responsiveness

We have observed substantial differences in angiogenic responsiveness in mice and have mapped the genetic loci responsible for these differences. We have found that the albino mutation is one of the loci responsible for such differences. Using B6.A consomic strains, we determined that chromosome 7 bears a locus that inhibits VEGF-induced corneal neovascularization. F2 crosses between B6.A<Chromosome 7> consomic mice and C57BL/6J parents along with AXB and BXA recombinant inbred strains demonstrated highest linkage near the tyrosinase gene. This region was named AngVq4. Congenic animals confirmed this locus, but could not demonstrate that the classical tyrosinase albino (c) mutation was causative because of the existence of additional linked loci in the congenic region. However, in 1970, a second tyrosinase albino mutation (c-2J) arose in the C57BL/6J background at Jackson Labs. Testing this strain (C57BL/6J<c-2J>) demonstrated that the albino mutation is sufficient to completely explain the alteration in angiogenic response that we observed in congenic animals. Thus, we conclude that the classical tyrosinase mutation is responsible for AngVq4. In contrast to the cornea, where pigmented animals exhibit increased angiogenic responsiveness, iris neovascularization was inhibited in pigmented animals. These results may partially explain increased aggressiveness in amelanotic melanoma, as well as ethnic differences in diabetic retinopathy and macular degeneration.