Macrophage migration inhibitory factor in the human endometrium: expression and localization during the menstrual cycle and early pregnancy

Macrophage Migration Inhibitory Factor Contributes to Adverse Outcomes of Experimental Gestational Malaria across Pregnancy Stages

Malaria infection during pregnancy, particularly caused by Plasmodium falciparum, poses significant risks, such as maternal anemia, low birth weight, preterm delivery, and increased infant mortality. This study investigated the role of macrophage migration inhibitory factor (MIF) in modulating pregnancy outcomes in a mouse model of gestational malaria. Herein, Mif-deficient (Mif-/-) and Mif-sufficient (wild-type) mice were used to evaluate the impact of MIF on maternal-fetal immune interactions during Plasmodium infection in three different stages of pregnancy. Mif-/- mice exhibited lower embryo resorption rates, preserved decidualization, and improved spiral artery remodeling compared with wild-type counterparts. Notably, although Mif deficiency was associated with increased parasitemia levels in late gestation, a shift toward a more anti-inflammatory phenotype in the uteroplacental tissues of infected mice contributed to better pregnancy outcomes. These results highlight the complex interplay between immune regulation and pregnancy in the context of malaria, indicating that targeting Mif may offer a therapeutic strategy to mitigate adverse pregnancy effects in infected individuals.

Secretory Proteomic Responses of Endometrial Epithelial Cells to Trophoblast-Derived Extracellular Vesicles

Synchronized crosstalk between the embryo and endometrium during the periconception period is integral to pregnancy establishment. Increasing evidence suggests that the exchange of extracellular vesicles (EVs) of both embryonic and endometrial origin is a critical component of embryo-maternal communication during peri-implantation. Here, we investigated whether embryonic signals in the form of EVs can modulate the endometrial epithelial cell secretome. Receptive endometrial analog RL95-2 cells were supplemented with trophoblast analog JAr cell-derived EVs, and the secretory protein changes occurring in the RL95-2 cells were analyzed using mass spectrometry. EVs of non-trophoblastic origin (HEK 293 cells) were used as the control EV source to supplement endometrial cells. Trophoblast cell-derived EVs enriched endometrial epithelial cell secretions with proteins that support embryo development, attachment, or implantation, whereas control EVs were unable to induce the same effect. The present study suggests that embryonic signals in the form of EVs may prime receptive endometrial epithelial cells to enrich their secretory proteome with critical proteomic molecules with functional importance for periconception milieu formation.

Therapeutic potential of curcumin in endometrial disorders: Current status and future perspectives

Endometrial disorders collectively encompass a broad spectrum of pathologies, including but not limited to endometriosis, endometrial cancer and endometritis. The current therapeutic management of these diseases is associated with several limitations. This has prompted interest in the use of plant-based bioactive compounds as alternative strategies to achieve high therapeutic efficacy and avoid adverse effects. In this context, curcumin, a polyphenol abundantly present in turmeric, is gaining increasing attention for its therapeutic potential to restore homeostasis in endometrial dysfunctionality. We comprehensively review the multifaceted role of curcumin, discussing mechanistic insights in various endometrial pathologies. We also provide an in-depth analysis of the concerns and challenges associated with the role of curcumin in endometrial research and outline a road map for future investigations.

Macrophage migration inhibitory factor in human early pregnancy events and association with placental pathologies

Macrophage migration inhibitory factor (MIF) is a versatile cytokine acting as an important regulator of innate and adaptive immunity and implicated in many physiological and pathological processes. It is abundantly expressed at the feto-maternal interface and proposed to have a role in establishing and maintaining a healthy pregnancy. This review presents the current literature data regarding the MIF role in early pregnancy events and its association with some of the placental pathological conditions, including infection, preeclampsia, gestational diabetes mellitus and choriocarcinoma. General information regarding MIF structure and function is followed by an overview of its expression in reproductive tissues and in pregnancy. Futher, we discuss MIF's involvement in the survival of decidual stromal cells, placenta of the first trimester of pregnancy, and in trophoblast cell functions studied in vitro. Current findings associating this cytokine to placental infection, preeclampsia, gestational diabetes mellitus and choriocarcinoma are presented in the final part.

Role of the Macrophage Migration Inhibitory Factor in the Pathophysiology of Pre-Eclampsia

Proinflammatory cytokines are produced in pregnancy in response to the invading pathogens and/or nonmicrobial causes such as damage-associated molecules and embryonic semi-allogenic antigens. While inflammation is essential for a successful pregnancy, an excessive inflammatory response is implicated in several pathologies including pre-eclampsia (PE). This review focuses on the proinflammatory cytokine macrophage migration inhibitory factor (MIF), a critical regulator of the innate immune response and a major player of processes allowing normal placental development. PE is a severe pregnancy-related syndrome characterized by exaggerated inflammatory response and generalized endothelial damage. In some cases, usually of early onset, it originates from a maldevelopment of the placenta, and is associated with intrauterine growth restriction (IUGR) (placental PE). In other cases, usually of late onset, pre-pregnancy maternal diseases represent risk factors for the development of the disease (maternal PE). Available data suggest that low MIF production in early pregnancy could contribute to the abnormal placentation. The resulting placental hypoxia in later pregnancy could produce high release of MIF in maternal serum typical of placental PE. More studies are needed to understand the role of MIF, if any, in maternal PE.

Serum macrophage migration inhibition factor for diagnosing endometriosis and its severity: case-control study

Background

Endometriosis is a long-standing progressive disease that affects women of reproductive age. Macrophage migration inhibitory factor (MIF) is one of non-invasive blood biomarker that was detected in sera of endometriotic patients. The present study aimed to determine the accuracy of serum MIF in diagnosing endometriosis in women with infertility and chronic pelvic pain, and correlate its level to the stage of the disease.

Methods

Observational case-control study conducted at Fayoum University hospital from March 2016 till September 2018. Three hundred women candidate for diagnostic laparoscopy for either infertility or gynecologic chronic pelvic pain were included. The study group included patients with symptoms suggestive of endometriosis or chocolate cyst by ultrasound and proved by laparoscopy and histopathology. The control group included other causes of infertility or pelvic pain. All patients undergone either diagnostic or operative laparoscopy, and before laparoscopy blood sampling for quantitative measurement of macrophage migration inhibitory factor (MIF) protein in serum by ELISA technique.

Results

The level of serum MIF was significantly higher in endometriosis group compared to control group (1.75 ± 1.48 pg/ml and 0.51 ± 0.45 pg/ ml, respectively, P = < 0.001), with a progressive increase with advancing stage (stage I, 1.3 ± 1.03 pg/ml, stage II, 1.7 ± 1.57 pg/ml, stage III, 2.1 ± 1.19 pg/ml and in stage IV, 3.2 ± 2.6 pg/ml). Moreover, in patients presented with pain and infertile patients showed significantly higher levels of serum MIF (1.92 ± 1.13 vs 1.21 ± 1.17 and 1.82 ± 1.13 vs 1.32 ± 0.91 respectively with p-value < 0.001). ROC curve of serum MIF with a cut off value of 0.85 pg/ml or more achieves a sensitivity of 80.6%, specificity of 83.3%, positive predictive value of 82.9% and negative predictive value of 81.2%.

Conclusion

Serum MIF might be a promising marker not only for noninvasive diagnosis of endometriosis but as a target for detecting severity as well.

Macrophage migration inhibitory factor is involved in endovascular trophoblast cell function in vitro

Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine abundantly present at the feto-maternal interface proposed to play a role in establishment of pregnancy. We have previously shown that pharmacological inhibition of enzymatic activity of MIF decreases extravillous trophoblast invasion and migration in vitro. This study aimed to further elucidate potential role of endogenous trophoblast MIF, and to assess its importance for endovascular trophoblast cell function in particular. Attenuation of MIF by siRNA reduced HTR-8/SVneo cell invasion through Matrigel (59 % of control), expression of integrin α₁ (86 % of control) and levels of MMP2 and MMP9 (87 % and 57 % of control, respectively). MIF specific siRNA reduced the ability of HTR-8/SVneo to differentiate in to endothelial-like phenotype, as determined by Matrigel tube formation assay. The total tube length was decreased to 68.6 %, while the number of branching points was reduced to 57.8 % of control. HTR-8/SVneo cell capacity to integrate into HUVEC monolayers was reduced by knock-down of MIF. This could be partly caused by reduced N-cadherin expression to 63 % of control, which decreased with knock-down of MIF, as the expression of this protein was recently shown essential for trophoblast-endothelial interaction. These novel findings indicate a novel role for trophoblast MIF in spiral artery remodeling process.

Role of the Macrophage Migration Inhibitory Factor (MIF) in the survival of first trimester human placenta under induced stress conditions

Macrophage Migration Inhibitory Factor (MIF) is a multifunctional molecule highly secreted by human placenta mainly in the early phases of pregnancy. Studies in different cells show that MIF is a pro-survival factor by binding to its receptor CD74. By using the in vitro model of placental explants from first trimester pregnancy, we investigated the role of MIF in the survival of placental cells under induced stress conditions that promote apoptosis or mimic the hypoxia/re-oxygenation (H/R) injury that placenta could suffer in vivo. We demonstrated that recombinant MIF (rMIF) treatment was able to reduce caspase-3 activation when cultures were challenged with the apoptosis-inducer Carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) while, in the cultures exposed to H/R, the treatment with rMIF did not show any effect. However, a significant increase in caspase-3 and caspase-8 activation was found when H/R-exposed cultures, were treated with anti-MIF or anti-CD74 antibody. We also observed that under H/R, a significant amount of endogenous MIF was released into the medium, which could account for the lack of effect of rMIF added to the cultures. Our results demonstrate for the first time that the MIF/CD74 axis contributes to maintain trophoblast homeostasis, by preventing abnormal apoptotic death.

Weathering the storm; a review of pre-pregnancy stress and risk of spontaneous abortion

The Weathering Effect is a theory that links stress exposure, over the life-course, with racial disparities in reproductive outcomes, through the effects of social adversity on a woman's body. The concept of maternal "weathering" captures cumulative somatic and psychological adversities that can exacerbate the effects of aging. Much of the evidence for weathering comes from observational studies linking self-report measures with reproductive outcomes. The purpose of this review is to explore biological mechanisms that underlie these observations. We focus on spontaneous abortion because this event is understudied despite evidence of racial disparities in this outcome. Spontaneous abortion is the most common pregnancy failure, and it happens early in pregnancy. Early pregnancy is a time most susceptible to the harmful effects of immune dysregulation that may, in part, result from adversities experienced before pregnancy begins. In exploring these mechanisms, we draw on well-defined signaling processes observed in the stressor-depression relationship. Pro-inflammatory dysregulation, for example, has particular relevance to immunological control occurring early in pregnancy. Early pregnancy immunologic changes affect the trajectories of pregnancy via control of trophoblastic invasion. Within the first few weeks of pregnancy, uterine derived cytokines operate within cytokine networks and play a critical role in this invasion. Programming for pro-inflammatory dysregulation can occur before conception. This dysregulation, brought into early pregnancy, has implications for viability and success of the index pregnancy. These patterns suggest early pregnancy health is susceptible to stress processing pathways that influence this immunologic control in the first six to eight weeks of pregnancy. In this review, we discuss the known mediating role of immune factors in the stressor-depression relationship. We also discuss how adversity experienced before the index pregnancy, or "pre-pregnancy" may influence these pathways, and subsequently influence early pregnancy health. There is a need to understand adversity, experienced before pregnancy, and mechanisms driving the effects of these experiences on pregnancy outcomes. This approach is a useful entry point for understanding racial inequities in pregnancy health through an understanding of differences in exposures to adversity. We hypothesize that spontaneous abortion involves cyclical changes within a woman's reproductive tract in response to stressors that are established well before a woman enters into pregnancy. Furthermore, we propose mechanisms that potentially drive weathering processes relevant to reproductive disparities. We also examine what is known about pre-pregnancy stress exposures associated with race, inequity, and adversity, and their potential impact on neuroendocrine and immune changes affecting early pregnancy risk.

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.

Suppressed expression of macrophage migration inhibitory factor in the oviducts of lean and obese cows

Oviducts synthesise macrophage migration inhibitory factor (MIF) to promote sperm capacitation and embryogenesis. This study aimed to test a hypothesis that the oviducts of obese cows may express MIF at a lower level than those of normal and lean cows. Ampullar and isthmic oviduct sections were collected from lean (n=5; body condition score (BCS) on a 5-point scale, 2.5), normal (n=6; BCS, 3.0) and obese (n=5; BCS, 4.0) Japanese Black cows. MIF mRNA and protein were extracted from ampullae and isthmuses and their levels measured by real-time polymerase chain reaction or western blot. Immunohistochemistry was performed on frozen sections of ampullae and isthmuses by using antibodies to MIF. MIF mRNA and protein expression were lower in the obese and lean groups than in the normal group (P<0.05). Immunohistochemistry revealed that the primary site of MIF expression in the ampulla and isthmus is the tunica mucosa. In conclusion, obese cows have suppressed MIF expression in the ampullae and isthmuses of their oviducts, as hypothesised, but, unexpectedly, MIF expression was also lower in lean cows.

Macrophage migration inhibitory factor induces phosphorylation of Mdm2 mediated by phosphatidylinositol 3-kinase/Akt kinase: Role of this pathway in decidual cell survival

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway has an anti-apoptotic effect through several downstream targets, which includes activation of the transformed mouse 3T3 cell double-minute 2 (Mdm2) protein, its translocation to the nucleus and degradation of the tumor suppressor p53. We show that Mif, the Macrophage Migration Inhibitory Factor, an important cytokine at the maternal fetal interface in several species, triggers phosphorylation of Mdm2 protein in a PI3K/Akt-dependent manner, thereby preventing apoptosis in cultured mouse decidual cells. Inhibition of Akt and PI3K suppresses the pathway. Mif treatment also changes the nuclear translocation of p53 and interferes with the apoptotic fate of these cells when challenged with reactive oxygen species. In conclusion, an important mechanism has been found underlying decidual cell survival through Akt signaling pathway activated by Mif, suggesting a role for this cytokine in decidual homeostasis and in the integrity of the maternal-fetal barrier that is essential for successful gestation.

Association between macrophage migration inhibitory factor in the endometrium and estrogen in endometriosis

Recent studies have shown that macrophage migration inhibitory factor (MIF) has a possible role in endometriosis-related pain and infertility, yet it has not been explored whether the mRNA level of MIF is altered in endometrial tissues from patients with endometriosis. The aim of the present study was to compare the expression of MIF in endometrial tissues from women with and without endometriosis, and to analyze the association between endometrial MIF expression and 17β-estradiol (E2). The protein and mRNA expression of MIF in the human endometrial tissue was assessed by western blotting and reverse transcription-polymerase chain reaction analysis, respectively. The MIF expression of women with endometriosis was found to be significantly higher than that of the controls. A positive correlation was noted between the serum E2 level and MIF expression. In endometrial cells from women with endometriosis, the level of E2-induced MIF upregulation was significantly higher than that in cells from women without endometriosis. In conclusion, this study demonstrated a significant increase in MIF expression in the endometrial tissues of women with endometriosis and an association between MIF expression and E2 level. MIF expression in endometrial cells from patients with endometriosis showed an increased sensitivity to stimulation by E2.

Bisphenol A modulates receptivity and secretory function of human decidual cells: an in vitro study

The human endometrium is a fertility-determining tissue and a target of steroid hormones' action. Endocrine disruptors (EDs) can exert adverse effects on the physiological function of the decidua at the maternal-fetal interface. We examined the potential effects of an ED, bisphenol A (BPA), on endometrial maturation/decidualization, receptivity, and secretion of decidual factors (biomarkers). In vitro decidualized, endometrial stromal cells from six hysterectomy specimens were treated with 1  pM-1  μM of BPA, for 24  h and assessed for cell viability and proliferation. Three non-toxic concentrations of BPA (1  μM, 1  nM, and 1  pM) were selected to study its influence on secretion of cell decidualization biomarkers (IGF-binding protein and decidual prolactin (dPRL)), macrophage migration inhibitory factor (MIF) secretion, and hormone receptors' expression (estrogen receptors (ERα and ERβ); progesterone receptors (PRA and PRB); and human chorionic gonadotropin (hCG)/LH receptor (LH-R)). The results showed a decrease in cell viability (P<0.001) in response to BPA at the level of 1  mM. At the non-toxic concentrations used, BPA perturbed the expression of ERα, ERβ, PRA, PRB, and hCG/LH-R (P<0.05). Furthermore, 1  μM of BPA reduced the mRNA transcription of dPRL (P<0.05). Secretion of MIF was stimulated by all BPA treatments, the lowest concentration (1  pM) being the most effective (P<0.001). The multi-targeted disruption of BPA on decidual cells, at concentrations commonly detected in the human population, raises great concern about the possible consequences of exposure to BPA on the function of decidua and thus its potential deleterious effect on pregnancy.

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.

Macrophage migration inhibitory factor and placental malaria infection in an area characterized by unstable malaria transmission in central Sudan

Background: The pathogenesis of malaria during pregnancy is not fully understood. A proinflammatory cytokine, macrophage migration inhibitory factor (MIF) is suggested as a factor involved in the pathogenesis of malaria during pregnancy.

Methods: A cross-sectional study was conducted in Medani Hospital, Sudan to investigate MIF levels in placental malaria. Obstetrical and medical characteristics were gathered from each parturient woman using questionnaires. All women (151) were investigated for malaria using blood film and placental histology. MIF levels were measured using ELISA in paired maternal and cord blood samples.

Results: There were no P. falciparum-positive blood films obtained from maternal peripheral blood, placenta or cord samples. Out of 151 placentae, four (2.6%), one (0.7%), 32 (21.2%) showed acute, chronic and past infection on histopathology examinations respectively, while the rest (114; 75.5%) of them showed no signs of infection.There was no significant difference in the median (interquartile) of maternal [5.0 (3.7─8.8) vs 6.2(3.5─12.0) ng/ml, P=0.643] and cord [8.1(3.3─16.9) vs 8.3(4.2─16.9), ng/ml, P= 0.601] MIF levels between women with a positive result for placental malaria infection (n=37) and women with a negative result for placental malaria infection (n=114). In regression models placental malaria was not associated with maternal MIF, hemoglobin or birth weight. MIF was not associated with hemoglobin or birth weight .

Conclusion: There was no association between maternal and cord MIF levels, placental malaria, maternal hemoglobin and birth weight.

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 as a potential biomarker of endometriosis

OBJECTIVE

To evaluate the expression of MIF, CD74, and COX-2 in normal, ectopic, and eutopic endometrium during the menstrual cycle and to assess MIF level in peripheral blood.

DESIGN

The expressions of MIF, CD74, and COX-2 in normal, ectopic, and eutopic endometrium were evaluated with the use of real-time polymerase chain reaction. MIF protein in peripheral blood samples was checked with the use of ELISA.

SETTING

Reproductive biomedicine research center.

PATIENT(S)

Sixteen normal women and 20 women with endometriosis.

INTERVENTION(S)

Ectopic biopsies were obtained with the use of laparoscopic procedure, and eutopic and control biopsies were obtained with the use of Pipelle. Peripheral blood samples were collected before laparoscopy.

MAIN OUTCOME MEASURE(S)

The expression of MIF, CD74, and COX-2 in normal, ectopic and eutopic endometrium during the menstrual cycle and the expression level of MIF in peripheral blood samples.

RESULT(S)

Relative mRNA expression of MIF, CD74, and COX-2 were significantly higher in ectopic endometrium than in eutopic and control endometrium. Also, there were significant differences in expression of these genes in normal, ectopic, and eutopic endometrium during the menstrual cycle. Moreover, women with endometriosis had significantly higher circulating levels of MIF compared with control subjects.

CONCLUSION(S)

Dynamic expression of MIF, CD74, and COX-2 during the menstrual cycle could play an essential role in reproduction, inflammation, and endometrium reconstruction. A higher expression of these genes in ectopic endometrium can be considered as a molecular biomarker for endometriosis development and pathophysiology. Also, a high level of MIF in blood serum can act as a biomarker in the diagnosis of endometriosis.

The transcriptomic and proteomic effects of ectopic overexpression of miR-30d in human endometrial epithelial cells

miR-30d is known to be up-regulated during the acquisition of receptivity in the endometrium. In order to determine the transcriptomic and proteomic changes which occur after transient overexpression of miR-30d in primary endometrial epithelial cells, in vitro cultured human endometrial epithelial cells (hEECs) were studied experimentally. Two different miRNAs (scramble versus mimic; n = 15) were transiently transfected into primary hEECs from four different patients and were evaluated for mRNA and protein expression using Agilent's gene expression microarray and iTRAQ analysis techniques, respectively. A set of differentially expressed mRNAs were validated by qPCR and several differentially expressed proteins were validated by western blot. Finally, methylation differential immunoprecipitation (MeDIP) was used to validate the epigenetic changes in the H19 gene. The results showed that transient transfection with miR-30d miRNA induced the differential mRNA-expression of 176 genes (75 up-regulated and 101 down-regulated). Several of them have been associated with reproductive and endocrine system disorders, tissue development, and are implicated in epithelial cell proliferation. Also, the down-regulation of some genes such as H19 and N-methyltransferase (NNMT) may suggest that epigenetic alterations are induced. Furthermore, upstream effects of genes regulated by the estrogen receptor alpha 1 (ESR1) transcription factor have been predicted. Proteomic analysis identified 2290 proteins, of which 108 were differentially expressed (47 up-regulated and 61 down-regulated). Among these differentially expressed proteins DNA methyl transferase (DNMT)1 was found to be up-regulated; this protein participates in the maintenance of DNA methylation, supporting an epigenetic role for miR-30d. Finally MeDIP showed an increase in methylation in the H19 DMR region. In conclusion transient in vitro overexpression of the receptivity-up-regulated miRNA miR-30d in hEECs seems to activate genes which are associated with hormonal response and the epigenetic status of these cells.

Profiles of cytokines secreted by isolated human endometrial cells under the influence of chorionic gonadotropin during the window of embryo implantation

BACKGROUND

Several studies have indicated that human pre-implantation embryo-derived chorionic gonadotropin (hCG) may influence the implantation process by its action on human endometrial epithelial and stromal cells. Despite reports indicating that hCG acts on these cells to affect the production of several cytokines and growth factors (e.g., MIF, IGF-I, VEGF, LIF, IL-11, GMCSF, CXL10 and FGF2), our understanding of the integral influence of hCG on paracrine interactions between endometrial stromal and epithelial cells during implantation is very limited.

METHODS

In the present study, we examined the profile of 48 cytokines in the conditioned media of primary cell cultures of human implantation stage endometrium. Endometrial epithelial cells (group 1; n = 20), stromal cells (group 2; n = 20), and epithelial plus stromal cells (group 3; n = 20) obtained from mid-secretory stage endometrial samples (n = 60) were grown on collagen and exposed to different doses (0, 1, 10 and 100 IU/ml) of rhCG for 24 h in vitro. Immunochemical and qRT-PCR methods were used to determine cytokine profiles. Enrichment and process networks analyses were implemented using a list of cytokines showing differential secretion in response to hCG.

RESULTS

Under basal conditions, endometrial epithelial and stromal cells exhibited cell type-specific profiles of secreted cytokines. Administration of hCG (100 IU) resulted in significantly (P < 0.05) different cytokine secretion profiles indicative of macropinocytic transport (HGF, MCSF) in epithelial cells, signal transduction (CCL4, FGF2, IL-1b, IL-6, IL-17, VEGF) in stromal cells, and epithelial-mesenchymal transition (FGF2, HGF, IL-1b, TNF) in mixed cells. Overall, the administration of hCG affected cytokines involved in the immune response, chemotaxis, inflammatory changes, proliferation, cell adhesion and apoptosis.

CONCLUSIONS

CG can influence the function of the endometrium during blastocyst implantation via its differential action on endometrial epithelial and stromal cells. CG may also affect complex paracrine processes in the different endometrial cell types.

Review: putative roles for the macrophage migratory inhibitory factor at the maternal fetal interface

Complex and dynamic networks of molecules participate in the essential interactions between maternal organism, placenta and fetus in a healthy and successful pregnancy. Macrophage migratory inhibitory factor (MIF) is one of several molecules produced at implantation sites; MIF is mostly expressed by trophoblast cells. This has led to expectations of MIF's relevance as a partner in the maternal/fetal dialog. MIF is known by its biological interactions and functional roles as an activator of innate immunity, regulating subsequent adaptive responses, which include inhibition of migration of mononuclear cells in vitro, antagonism of glucocorticoids, and regulation of expression of Toll-like receptor 4. Beyond roles in the inflammatory response, MIF can interfere with proliferative activities in different cell types, as well as with cell death pathways. This intriguing factor found at the human, porcine, ovine, bovine and rodent maternal-fetal interfaces is present in a time- and spatially-dependent manner, indicating regulatory roles in the process of embryo implantation, placental development, maintenance of pregnancy and birth. Here, we will review MIF participation in placental physiology, including new evidence for a dialog with uterine cells, and a potential role in protection of uterine decidual cells.

Pro-inflammatory profile of preeclamptic placental mesenchymal stromal cells: new insights into the etiopathogenesis of preeclampsia

The objective of the present study was to evaluate whether placental mesenchymal stromal cells (PDMSCs) derived from normal and preeclamptic (PE) chorionic villous tissue presented differences in their cytokines expression profiles. Moreover, we investigated the effects of conditioned media from normal and PE-PDMSCs on the expression of pro-inflammatory Macrophage migration Inhibitory Factor (MIF), Vascular Endothelial Growth Factor (VEGF), soluble FMS-like tyrosine kinase-1 (sFlt-1) and free β-human Chorionic Gonadotropin (βhCG) by normal term villous explants. This information will help to understand whether anomalies in PE-PDMSCs could cause or contribute to the anomalies typical of preeclampsia.

METHODS

Chorionic villous PDMSCs were isolated from severe preeclamptic (n = 12) and physiological control term (n = 12) placentae. Control and PE-PDMSCs's cytokines expression profiles were determined by Cytokine Array. Control and PE-PDMSCs were plated for 72 h and conditioned media (CM) was collected. Physiological villous explants (n = 48) were treated with control or PE-PDMSCs CM for 72 h and processed for mRNA and protein isolation. MIF, VEGF and sFlt-1 mRNA and protein expression were analyzed by Real Time PCR and Western Blot respectively. Free βhCG was assessed by immunofluorescent.

RESULTS

Cytokine array showed increased release of pro-inflammatory cytokines by PE relative to control PDMSCs. Physiological explants treated with PE-PDMSCs CM showed significantly increased MIF and sFlt-1 expression relative to untreated and control PDMSCs CM explants. Interestingly, both control and PE-PDMSCs media induced VEGF mRNA increase while only normal PDMSCs media promoted VEGF protein accumulation. PE-PDMSCs CM explants released significantly increased amounts of free βhCG relative to normal PDMSCs CM ones.

CONCLUSIONS

Herein, we reported elevated production of pro-inflammatory cytokines by PE-PDMSCs. Importantly, PE PDMSCs induced a PE-like phenotype in physiological villous explants. Our data clearly depict chorionic mesenchymal stromal cells as central players in placental physiopathology, thus opening to new intriguing perspectives for the treatment of human placental-related disorders as preeclampsia.

The importance of the macrophage within the human endometrium

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

Macrophage migration inhibitory factor in fetoplacental tissues from preeclamptic pregnancies with or without fetal growth restriction

The proinflammatory cytokine MIF (macrophage migration inhibitory factor) is involved in physiological and pathological processes in pregnancy. MIF maternal serum levels are increased in preeclampsia (PE). We hypothesize that pregnancy tissues are the source of MIF overexpression in PE. MIF protein was studied in maternal sera, placental tissues, fetal membranes, and umbilical cord of 8 control and 20 PE pregnancies: 10 with normal fetal growth (PE-AGA) and 10 with fetal growth restriction (PE-FGR). MIF levels were significantly higher in PE-AGA membranes than in controls and PE-FGR. In PE-FGR, MIF cord concentrations were higher than in PE-AGA while MIF placental levels were lower than in controls. MIF maternal serum levels were higher in PE, compared to controls, and the difference was mainly due to PE-FGR samples. These data support MIF involvement in PE pathogenesis and suggest that different pregnancy tissues contribute to MIF production in PE with and without fetoplacental compromise.

Sheep (Ovis aries) Macrophage Migration Inhibitory Factor: molecular cloning, characterization, tissue distribution and expression in the ewe reproductive tract and in the placenta

Macrophage Migration Inhibitory Factor (MIF) is a pivotal regulator of innate and acquired immunity affecting the response and behavior of macrophages and lymphocytes. However, a number of studies indicated wider physiological functions for this cytokine to include key-roles in reproductive biology. The present study was designed to clone the coding sequence of sheep MIF, to examine the characteristics of the protein in vitro, and to evaluate its expression in sheep tissues and in the ewe reproductive tract in vivo. Ovine MIF cDNA consisted of 348 nucleotides encoding a 115 amino acids protein with an estimated molecular mass of 12,343 Da and an isoelectric point of 7.68. Sheep MIF shared high amino acid identity with the other mammalian MIF family members and showed parallel functions to human MIF, displaying enzymatic oxoreductase activity and inducing monocyte transmigration. Expression studies detected a MIF transcript in all the sheep tissues examined. Among reproductive tissues, MIF mRNA and protein were detected in the ovary, oviduct, uterus and placenta. These results indicate that sheep MIF shares crucial features with other MIF family members and delineate its potential involvement in several aspects of ovine physiology.

Differential susceptibility of human trophoblastic (BeWo) and uterine cervical (HeLa) cells to Neospora caninum infection

Neospora caninum is an apicomplexan parasite, closely related to Toxoplasma gondii, and causes abortion and congenital neosporosis in cattle worldwide. Trophoblast cells act in mechanisms of innate immune defense at the fetal-maternal interface and no data are available about the interaction of Neospora with human trophoblasts. Thus, this study aimed to verify the susceptibility of human trophoblastic (BeWo) compared with uterine cervical (HeLa) cell lines to N. caninum. BeWo and HeLa cells were infected with different parasite:cell ratios of N. caninum tachyzoites and analyzed at different times after infection for cell viability using thiazolyl blue tetrazole and lactate dehydrogenase assays. Both cell lines were also evaluated for cytokine production and parasite infection/replication assays when pre-treated or not with Neospora lysate antigen (NLA) or human recombinant IFN-γ. Cell viability was increased up to 48 h of infection in both types of cells, suggesting that infection could inhibit early cell death and/or induce cell proliferation. Neospora infection induced up-regulation of the macrophage migration inhibitory factor (MIF), mainly in HeLa cells, which was enhanced by cell pre-treatment by NLA or IFN-γ. Conversely, parasite infection induced down-regulation of the transforming growth factor (TGF-β), mostly in BeWo cells, which was decreased with NLA or IFN-γ pre-treatment. HeLa cells were more susceptible to Neospora infection than BeWo cells and IFN-γ pre-treatment resulted in reduced infection indices in both cell lines. Control of parasite growth was mediated by IFN-γ through an indoleamine-2,3-dioxygenase-dependent mechanism in HeLa cells alone. Based on these results, we concluded that BeWo and HeLa cells are readily infected by N. caninum, although presenting differences in susceptibility to infection, cytokine production and cell viability. Thus, these host cells can be considered in comparative approaches to understand strategies used by N. caninum to survive at the maternal-fetal interface.

Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta

BACKGROUND

Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy.

METHODS

Mif was immunolocalized at implantation sites on gestation days (gd) 7.5, 10.5, 13.5 and 17.5. Ectoplacental cones and fetal placentas dissected from the maternal tissues were used for Western blotting and qRT-PCR assays on the same gestation days.

RESULTS

During the post-implantation period (gd7.5), trophoblast giant cells showed strong Mif reactivity. In later placentation phases (gds 10.5-17.5), Mif appeared to be concentrated in the junctional zone and trophoblast giant cells. Mif protein expression increased significantly from gd7.5 to 10.5 (p = 0.005) and from gd7.5 to 13.5 (p = 0.03), remaining at high concentration as gestation proceeded. Higher mRNA expression was found on gd10.5 and was significantly different from gd13.5 (p = 0.048) and 17.5 (p = 0.009).

CONCLUSIONS

The up-regulation of Mif on gd10.5 coincides with the stage in which the placenta assumes its three-layered organization (giant cells, spongiotrophoblast and labyrinth zones), fetal blood circulation begins and population of uNK cells reaches high proportions at the maternal counter part of the placenta, suggesting that Mif may play a role in either the placentation or in the adaptation of the differentiated placenta to the uterus or still in gestational immunomodulatory responses. Moreover, it reinforces the possibility of specific activities for Mif at the maternal fetal interface.

17{beta}-Estradiol modulates the macrophage migration inhibitory factor secretory pathway by regulating ABCA1 expression in human first-trimester placenta

Successful pregnancy involves a series of events, most of them mediated by hormones and cytokines. Estrogens, besides being important for placental growth and embryo development, have a marked effect on the immune system exerting either pro- or anti-inflammatory properties. Numerous studies suggest that estrogens directly affect cellular function, including cytokine production. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in pregnancy, particularly during the earlier stages of placentation. Since reports on mice have shown that estrogens modulate MIF, herein we investigated the effect of estrogens on human placental MIF. By using an in vitro model of first-trimester chorionic villous explants, we found that 17beta-estradiol (E(2)) was able to modulate the release of MIF in a dose-dependent manner (10(-12) vs. 10(-9) M, P < 0.05; 10(-9) vs. 10(-5) M, P < 0.05; 10(-12) vs. 10(-5) M, P < 0.001). Unlike MIF release, no significant change in tissue MIF protein or MIF mRNA was observed. We showed evidence that E(2) concentrations (10(-9) and 10(-5) M) act on placental tissue downregulating the mRNA and protein expression of the ATP-binding cassette transporter protein A1, a membrane transporter involved in MIF secretion. These findings emphasize the mutual cooperation between hormones and cytokines and suggest that increasing estrogen levels with advancing gestation may have a major role in regulating placental MIF secretion.

Serum macrophage migration inhibitory factor in the prediction of preterm delivery

OBJECTIVE

Macrophage migration inhibitory factor is a soluble mediator that helps govern the interaction between cytokines and stress hormones (eg, cortisol). We determined whether maternal macrophage migration inhibitory factor levels predicted subsequent preterm delivery.

STUDY DESIGN

A nested case-control study measuring serum macrophage migration inhibitory factor concentration at 9-23 weeks' gestation in women who ultimately delivered preterm (n = 60) compared with control women who delivered at term (n = 122). We also examined the connection of macrophage migration inhibitory factor with self-reported psychosocial variables.

RESULTS

Macrophage migration inhibitory factor was elevated in the preterm delivery cases (P = .0004), and log macrophage migration inhibitory factor concentration showed a graded response relationship with likelihood of preterm delivery. High-macrophage migration inhibitory factor was also associated with maternal risk-taking behavior, which itself was a risk factor for preterm delivery. Macrophage migration inhibitory factor remained associated independently with preterm delivery after adjusting regression models for several other preterm delivery risk factors (odds ratio, 3.11, 95% confidence interval, 1.54-6.30).

CONCLUSION

High-serum macrophage migration inhibitory concentration in early to midpregnancy is linked with subsequent preterm delivery.

Programming of human monocytes by the uteroplacental environment

During human pregnancy, monocytes recruited to the uterus (decidua) are modified to promote immune defense and semiallogeneic pregnancy. The purpose of this study was to identify decidual factors involved in programming of monocytes into decidual macrophages by comparing the surface and secretory phenotypes of resting and interferon- gamma (IFN-gamma)-activated monocytes, unfractionated decidual cells, purified term decidual macrophages, and monocyte-derived macrophages. Surface markers for antigen presentation (HLA-DR, CD86), a membrane-bound cytokine interleukin (IL)-15, leukocyte immunoglobulin-like receptors (LILRB1, LILRB2), and secreted anti-inflammatory cytokines (transforming growth factor [TGF]-beta1 and IL-10) were assessed. The results demonstrate that differentiated, activated monocytes closely resemble but are not identical to decidual macrophages. In addition to differential IFN-gamma responsiveness, decidual macrophages were smaller than monocyte-derived macrophages and produced IL-10, which monocyte-derived macrophages did not. Only the unfractionated decidual cells secreted TGF-beta1. These results suggest that activation, differentiation, and decidual signals cooperate to program monocytes into the decidual macrophage phenotype.

Macrophage migration inhibitory factor has a MHC class I-like motif and function

Macrophage migration inhibitory factor (MIF) is found in immune-privileged sites and inhibits cytotoxicity mediated by CD3-ve lymphokine-activated killer cells (LAK). The mechanism by which MIF attenuates LAK cytotoxicity is unknown. We provide evidence that MIF has a major histocompatibility complex (MHC) class I-like motif. A monoclonal antibody (OX18) that binds a conserved region of rat MHC class I proteins binds native MIF. Anti-MIF polyclonal antibodies bind MHC class I. Epitope mapping suggests OX18 binds a loop of MHC class I bound by several receptors for MHC class I. A sequence (PRPEG) within the proposed OX18-binding site on MHC class I exists with a short insertion in MIF. OX18 does not bind MIF that is denatured by SDS-PAGE. This suggests the OX18 epitope is dependent on higher order structure in MIF. Interestingly, MIF inhibits binding of tetramers of MHC class I (H2D(b)) to LAK cells, suggesting it may bind to receptors for MHC class I. MIF may be an example where small regions of MHC class I are used by endogenous and viral proteins to control cytotoxicity mediated by immune cells.

Systemic fetal inflammation and reduced concentrations of macrophage migration inhibitory factor in tracheobronchial aspirate fluid of extremely premature infants

OBJECTIVE

Macrophage migration inhibitory factor is a proinflammatory mediator of innate immunity, enhances cell growth, and plays a role in preterm delivery. We speculated that funisitis, reflecting fetal systemic inflammation, would be associated with higher concentrations of macrophage migration inhibitory factor in airways of extremely premature infants.

STUDY DESIGN

We measured macrophage migration inhibitory factor by enzyme linked immunosorbent assay in tracheobronchial aspirate fluid of 35 ventilated infants less than 30 weeks' gestational age, throughout the first week of life. Three groups were distinguished histologically: chorioamnionitis, funisitis, and control.

RESULTS

Unexpectedly, funisitis was associated with significantly decreased macrophage migration inhibitory factor in tracheobronchial aspirate fluid on day 1 (P < .01) and levels remained lower than in the chorioamnionitis group thereafter. For the 35 patients in total, macrophage migration inhibitory factor steadily declined.

CONCLUSION

Decreased macrophage migration inhibitory factor concentrations in airways of extremely premature infants with systemic fetal inflammation early in life might predispose them to pulmonary infection and interfere with maturation of the lung, contributing to adverse pulmonary outcome.

Macrophage migration inhibitory factor is up-regulated in human first-trimester placenta stimulated by soluble antigen of Toxoplasma gondii, resulting in increased monocyte adhesion on villous explants

Considering the potential role of macrophage migration inhibitory factor (MIF) in the inflammation process in placenta when infected by pathogens, we investigated the production of this cytokine in chorionic villous explants obtained from human first-trimester placentas stimulated with soluble antigen from Toxoplasma gondii (STAg). Parallel cultures were performed with villous explants stimulated with STAg, interferon-gamma (IFN-gamma), or STAg plus IFN-gamma. To assess the role of placental MIF on monocyte adhesiveness to human trophoblast, explants were co-cultured with human myelomonocytic THP-1 cells in the presence or absence of supernatant from cultures treated with STAg (SPN), SPN plus anti-MIF antibodies, or recombinant MIF. A significantly higher concentration of MIF was produced and secreted by villous explants treated with STAg or STAg plus IFN-gamma after 24-hour culture. Addition of SPN or recombinant MIF was able to increase THP-1 adhesion, which was inhibited after treatment with anti-MIF antibodies. This phenomenon was associated with intercellular adhesion molecule expression by villous explants. Considering that the processes leading to vertical dissemination of T. gondii remain widely unknown, our results demonstrate that MIF production by human first-trimester placenta is up-regulated by parasite antigen and may play an essential role as an autocrine/paracrine mediator in placental infection by T. gondii.

Antigen-presenting cells and materno-fetal tolerance: an emerging role for dendritic cells

During pregnancy, a delicate balance of innate and adaptive immune responses at the maternal-fetal interface promotes survival of the semi-allogeneic embryo and, at the same time, allows effective immunity to protect the mother from environmental pathogens. As in other tissues, antigen handling and processing in the decidualized endometrium constitutes a primary event in the onset of immune responses and is therefore likely to determine their stimulatory or tolerogenic nature. Maternal antigen-presenting cells [macrophages and dendritic cells (DCs)] are scattered throughout the decidualized endometrium during all stages of pregnancy and appear to be important players in this feto-maternal immune adjustment. This review focuses on the characterization of decidual macrophages and DCs, as well as their involvement in cell-cell interactions within the decidual leukocyte network, which are likely to influence uterine and placental homeostasis as well as the local maternal immune responses to the fetus during pregnancy.

Postgestational effects of macrophage migration inhibitory factor on embryonic implantation in mice

OBJECTIVE

To investigate in vivo the effects of macrophage migration inhibitory factor (MIF) on endometrial receptivity and embryonic implantation.

DESIGN

A murine experimental model.

SETTING

Animal facilities at Research Center of Saint-François d'Assise Hospital.

ANIMAL(S)

Ten-week-old B6C3F-1 female mice.

INTERVENTION(S)

Intraperitoneal injections of recombinant mouse MIF or saline (control) the day after successful mating and during the peri-implantation period.

MAIN OUTCOME MEASURE(S)

Markers of uterine receptivity, including integrins and vascular endothelial growth factor (VEGF) were assessed using real-time polymerase chain reaction (PCR) and immunohistochemistry.

RESULT(S)

Quantitative real-time PCR and immunohistochemical analyses indicated that MIF induced a marked increase in alpha(v) (alphav), beta3 (beta3) integrin subunits and VEGF mRNA, and protein expression in the endometrium. The MIF (10 microg/mL) significantly increased the number of von Willebrand factor-stained microvessels, and a significant correlation between VEGF expression and the number of von Willebrand factor-stained vessels was observed. Moreover, a tendency for an enhanced pregnancy rate (PR) in MIF-treated mice was seen compared with controls.

CONCLUSION(S)

These findings reveal that after gestation, MIF may play an important role in endometrial receptivity and embryonic implantation.

Macrophage migration inhibitory factor up-regulates alpha(v)beta(3) integrin and vascular endothelial growth factor expression in endometrial adenocarcinoma cell line Ishikawa

Human endometrium undergoes a series of dynamic physiological changes during the menstrual cycle of reproductive age women. Many factors, including hormones, cytokines, growth factors, matrix metalloproteinases and integrins, are essential for the success of embryonic implantation into endometrial tissue. Herein, we used a well-differentiated endometrial adenocarcinoma cell line, Ishikawa, to investigate in vitro the role played by macrophage migration inhibitory factor (MIF) in the regulation of endometrial receptivity markers. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that MIF induced a slight increase in alpha(v) (alphav) mRNA integrin subunit expression during the first 12h, but reached a significant difference after 24h MIF treatment compared to control, whereas beta(3) (beta3) integrin subunit displayed significant increase in mRNA 2h following treatment. Immunocytofluorescence showed strong alphav and beta3 immunostaining at 25 ng/ml MIF, and Western blotting clearly indicated increased alphav and beta3 protein expression. MIF treatment significantly stimulated vascular endothelial growth factor (VEGF) mRNA expression in a dose- and time-dependent manner after 24 h treatment. Moreover, immunocytofluorescence revealed positive VEGF immunostaining compared to control, and analysis by ELISA of VEGF release in culture supernatants demonstrated that MIF (25 ng/ml) significantly induced VEGF secretion at 12 and 24 h. In conclusion, this study provides evidence that MIF directly up-regulates alphavbeta3 integrin and VEGF expression in human endometrial Ishikawa cells and may advance our understanding of factors involved in the establishment of endometrial receptivity and successful implantation.

Imbalance in seminal fluid MIF indicates male infertility

Macrophage migration inhibitory factor (MIF) is a ubiquitous cytokine that functions in reproduction and plays an important role in sperm maturation and motility. Here we reveal a correlation between MIF levels in human seminal fluid and fertility status. We identify an abnormal biphasic profile of MIF in the seminal fluid of patients with impaired sperm parameters. Our findings may be of interest for the development of a diagnostic method for fertility status.

Imbalance in seminal fluid MIF indicates male infertility

Macrophage migration inhibitory factor (MIF) is a ubiquitous cytokine that functions in reproduction and plays an important role in sperm maturation and motility. Here we reveal a correlation between MIF levels in human seminal fluid and fertility status. We identify an abnormal biphasic profile of MIF in the seminal fluid of patients with impaired sperm parameters. Our findings may be of interest for the development of a diagnostic method for fertility status.

Macrophage migration inhibitory factor in patients with preterm parturition and microbial invasion of the amniotic cavity

OBJECTIVE

Macrophage migration inhibitory factor (MIF) has emerged as an important mediator of septic shock. The administration of MIF increases lethality during endotoxemia, whereas neutralization of this cytokine prevents endotoxic shock and death associated with bacterial infection. The objective of this study was to determine whether there is a change in the amniotic fluid concentration of MIF in intra-amniotic infection and human parturition.

STUDY DESIGN

A cross-sectional study was conducted in women in the following categories: (1) mid-trimester (n = 84); (2) preterm labor and intact membranes who delivered at term (n = 33), who delivered preterm (n = 53) and preterm labor with intra-amniotic infection (n = 23); (3) preterm premature rupture of membranes (PROM) with (n = 25) and without intra-amniotic infection (n = 26); and (4) term with intact membranes, in labor (n = 52) and not in labor (n = 31). MIF concentrations in amniotic fluid were determined using a sensitive and specific immunoassay. MIF concentrations in maternal plasma were also determined in patients with preterm labor and intact membranes. Immunohistochemistry was conducted in chorioamniotic membranes obtained from a different set of patients presenting with preterm labor with (n = 18) and without (n = 20) histologic chorioamnionitis. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure MIF mRNA expression in chorioamniotic membranes of patients with preterm labor with (n = 13) and without (n = 13) histologic chorioamnionitis. Parametric and non-parametric, receiver-operating characteristic (ROC) curve, survival analysis, and Cox regression model were used for analysis.

RESULTS

Immunoreactive MIF was detectable in 96% (313/327) of amniotic fluid samples. The concentration of amniotic fluid MIF at term was higher than that in the mid-trimester (p = 0.004). Intra-amniotic infection in women with preterm labor and preterm PROM was associated with a significant increase in median amniotic fluid MIF concentration (p < 0.001 and 0.004, respectively). Patients with preterm labor with sterile amniotic fluid who delivered preterm had a significantly higher median amniotic fluid MIF concentration than those who delivered at term (p = 0.007). Among patients with preterm labor with intact membranes, survival analysis indicated that the median amniocentesis-to-delivery interval was significantly shorter in patients whose amniotic fluid concentrations of MIF were above 302 ng/ml than those below this cutoff value (p < 0.001). Human parturition at term was not associated with changes in the amniotic fluid MIF concentrations (p > 0.05). There was no significant difference in median maternal plasma MIF concentrations among patients with preterm labor and intact membranes who delivered at term, those who delivered preterm, and those who had intra-amniotic infection (p > 0.05 for all comparisons). Immunohistochemistry demonstrated that MIF protein was present in amniotic epithelial cells, and the mean percentage of immunoreactive MIF-staining cells was higher in patients with histologic chorioamnionitis than in those without this lesion (p = 0.03). Similarly, the mean MIF mRNA expression was higher in chorioamniotic membranes obtained from patients with histologic chorioamnionitis than in those without this lesion (p = 0.03).

CONCLUSIONS

Intra-amniotic infection and preterm parturition, but not term parturition, are associated with a significant increase in amniotic fluid MIF concentrations. Among patients with preterm labor with intact membranes, elevated amniotic fluid concentrations of MIF are associated with intra-amniotic inflammation, histologic chorioamnionitis, and shorter amniocentesis-to-delivery interval. These changes in amniotic fluid were not reflected in maternal plasma. An increased expression of MIF protein and mRNA in chorioamniotic membranes was observed in patients with histologic choricamnionitis.

The role of macrophage migration inhibitory factor in maintaining the immune privilege at the fetal–maternal interface

Macrophage migration inhibitory factor (MIF) is a pivotal regulator of the innate and adaptive immunity affecting the response and behavior of macrophages and lymphocytes. MIF is also implicated in other fundamental cellular processes including angiogenesis and cell proliferation. Several studies examined the expression of MIF in reproductive organs and tissues and its involvement in different aspects of human and animal reproduction. The goal of this review was to summarize these findings and discuss, in particular, the role of MIF in the maintenance of the immune privilege at the human fetal-maternal interface.

Oxygen regulation of macrophage migration inhibitory factor in human placenta

Macrophage migration inhibitory factor (MIF) is an important proinflammatory cytokine involved in regulation of macrophage function. In addition, MIF may also play a role in murine and human reproduction. Although both first trimester trophoblast and decidua express MIF, the regulation and functional significance of this cytokine during human placental development remains unclear. We assessed MIF expression throughout normal human placental development, as well as in in vitro (chorionic villous explants) and in vivo (high altitude placentae) models of human placental hypoxia. Dimethyloxalylglycine (DMOG), which stabilizes hypoxia inducible factor-1 under normoxic conditions, was also used to mimic the effects of hypoxia on MIF expression. Quantitative real-time PCR and Western blot analysis showed high MIF protein and mRNA expression at 7-10 wk and lower levels at 11-12 wk until term. Exposure of villous explants to 3% O(2) resulted in increased MIF expression and secretion relative to standard conditions (20% O(2)). DMOG treatment under 20% O(2) increased MIF expression. In situ hybridization and immunohistochemistry showed elevated MIF expression in low oxygen-induced extravillous trophoblast cells. Finally, a significant increase in MIF transcript was observed in placental tissues from high-altitude pregnancies. Hence, three experimental models of placental hypoxia (early gestation, DMOG treatment, and high altitude) converge in stimulating increased MIF, supporting the conclusion that placental-derived MIF is an oxygen-responsive cytokine highly expressed in physiological in vivo and in in vitro low oxygen conditions.

Differential regulation of colony stimulating factor 1 and macrophage migration inhibitory factor expression by inflammatory cytokines in term human decidua: implications for macrophage trafficking at the fetal-maternal interface

Macrophages are a major component of the leukocyte population of human pregnant endometrium. Although several crucial functions have been ascribed to these cells, the mechanisms underlying macrophage trafficking in the placental bed are poorly understood. The aim of this study was to evaluate the in vivo expression of two potentially antagonistic macrophage-targeting chemokines, colony stimulating factor 1 (CSF1, also known as M-CSF) and macrophage migration inhibitory factor (MIF), in term decidua, and to examine the effects of the inflammatory cytokines tumor necrosis factor (TNF, also known as TNF alpha) and interleukin 1beta (IL1B) on CSF1 and MIF expression in cultured decidual cells. The expression of CSF1 and MIF in term decidua was evaluated by immunohistochemistry. Cultured decidual cells were primed with estradiol (E2) or with E2+medroxyprogesterone acetate (MPA), and then incubated with corresponding steroid(s) with or without TNF or IL1B. The levels of CSF1 and MIF protein and mRNA were assessed by ELISA and quantitative RT-PCR, respectively. Immunostaining for CSF1 and MIF was observed in term decidua. The levels of secreted CSF1 and MIF were similarly unchanged whether the decidual cells were incubated with E2 or with E2+MPA. The CSF1 levels significantly increased in cultures exposed to E2 or E2+MPA plus TNF or IL1B. In contrast, the MIF levels in TNF- and IL1B-treated cells were not changed significantly from the control cultures. The ELISA data were confirmed by quantitative RT-PCR analysis. These results indicate that CSF1 and MIF are involved in regulating macrophage trafficking at the fetal-maternal interface, and suggest a mechanism by which inflammatory cytokines influence pregnancy by regulating decidual macrophage infiltration.

Migration inhibitory factor secretion by polarized uterine epithelial cells is enhanced in response to the TLR3 agonist poly (I:C)

PROBLEM

Uterine epithelial cells produce cytokines that stimulate leukocytes in response to a microbial insult. The goals of this study were to determine if uterine epithelial cells produce the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF), and to see if toll-like receptor (TLR) agonists stimulate MIF secretion.

METHODS OF STUDY

Human uterine epithelial cells were isolated and grown in cell culture inserts. Levels of MIF secretion were examined by ELISA and MIF messenger RNA (mRNA) expression was examined using real time RT-PCR.

RESULTS

Uterine epithelial cells constitutively secrete MIF and exposure to the TLR3 agonist poly (I:C) resulted in enhanced apical secretion of MIF. MIF secretion appeared to be from pre-formed intracellular stores, since exposure of epithelial cells to poly (I:C) had little effect on the expression of MIF-mRNA.

CONCLUSIONS

These results demonstrate that uterine epithelial cells constitutively produce MIF and stimulation with poly (I:C) results in enhanced MIF production. This suggests that MIF secretion by uterine epithelial cells may play a critical role in innate immune responses against viral pathogens mediated through TLR3.

Human decidual natural killer cells as a source and target of macrophage migration inhibitory factor

The human uterine mucosa of early pregnancy is largely populated by CD56(bright) natural killer (NK) cells (uterine (u) NK cells). The specific functions of these cells are still unknown, but their interaction and response to foetal trophoblasts are thought to be important for the establishment of a successful pregnancy. The study reported herein shows that uNK cells respond to, and produce, macrophage migration inhibitory factor (MIF), a cytokine highly expressed in the human placenta and in the cyclic and pregnant endometrium. Recombinant human MIF reduced in a dose-dependent manner the cytolytic activity of purified uNK cells against K562 cells. RT-PCR, Western blot analysis and ELISA demonstrated the synthesis and secretion of the cytokine by uNK cells. Double immunofluorescence staining showed the presence of MIF in uterine CD56 + cells. Finally, neutralization of the endogenous cytokine by a polyclonal antibody resulted in a sharp increase in the cytolytic activity of uNK cells. These findings indicate the existence of a previously unrevealed paracrine and autocrine action of MIF on uNK cells and support its contribution to the immune privilege at the maternal-foetal interface.