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

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.

Antioxidant response element activator, BTZO-1, improves the developmental competence of bovine oocytes

Increased reactive oxygen species (ROS) generation may disrupt the oocytes function and their competence. In this study, we introduced BTZO-1, a new supplement that can regulate the oxidative stress. Addition of BTZO-1 during IVM of bovine oocytes improved their developmental competence in the term of improvement of blastocyst rates. In addition, the quality of the produced embryos was improved by decreasing the apoptosis level by showing a decreased number of TUNNEL positive cells.

Expression of macrophage migration inhibitory factor (MIF) in bovine oviducts is higher in the postovulatory phase than during the oestrus and luteal phase

Whether macrophage migration inhibitory factor (MIF) in the bovine oviduct is important for early embryogenesis has not been well substantiated. The aim of the present study was to test the hypothesis that bovine oviduct expresses higher levels of MIF during the post-ovulation phase. Both ampullary and isthmic samples were collected from Japanese black heifers during oestrus (Day 0; n=5), postovulation (Day 3; n=6) and luteal phase (Days 9-12; n=5). MIF mRNA and protein were extracted from the ampullary and isthmic samples and their levels measured by real-time polymerase chain reaction and western blot analysis respectively. Fluorescent immunohistochemistry was performed on frozen ampullary and isthmic sections using antibodies against MIF. MIF mRNA and protein expression was higher in the postovulatory phase than during oestrus and the luteal phase (P<0.05). Fluorescent immunohistochemistry confirmed that in all phases of the oestrous cycle evaluated, the primary site of MIF expression in the ampulla and isthmus was the tunica mucosa. In conclusion, the bovine ampulla and isthmus have higher MIF expression during the postovulatory phase. Further studies are needed to clarify the role of MIF in bovine oviducts.

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 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.

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.

Enhanced beta-catenin expression and inflammation are associated with human ectopic tubal pregnancy

STUDY QUESTION

Is there a molecular link between Wnt signaling in fallopian tube inflammation and ectopic tubal implantation?

SUMMARY ANSWER

Enhanced beta-catenin expression, reduced E-cadherin expression and glycogen accumulation in the tubal epithelia and hyperplasia in tubal arteries were found in ectopic tubal pregnancy, consistent with the effects induced by Wnt signaling and inflammation.

WHAT IS KNOWN ALREADY

Chronic inflammation caused by infection can alter gene expression in the fallopian tube cells possibly leading to the development of ectopic pregnancy. Knockout mouse models have shown a relationship between Wnt/beta-catenin signaling and predisposition to tubal ectopic pregnancy.

STUDY DESIGN, SIZE, DURATION

Women with ectopic tubal pregnancy (n = 18) were included in the case group, while women with chronic salpingitis (n = 13) and non-pregnant women undergoing sterilization procedures or salpingectomy for benign uterine disease (n = 10) were set as the controls. This study was performed between January 2012 and November 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The ampullary segments of fallopian tubes were collected from patients. Tissues of tubal pregnancy were separated into implantation sites and non-implantation sites. Beta-catenin and E-cadherin expression were determined using immunohistological and immunofluorescence staining. Glycogen production was measured with periodic acid Schiff by staining. The diameter and wall thickness of tubal arteries were evaluated by histological analysis method.

MAIN RESULTS AND THE ROLE OF CHANCE

Immunohistological staining revealed that beta-catenin protein expression was 100% positive in the ectopic pregnant and inflamed tubal tissues, and the staining intensity was significantly higher than in non-pregnant tubal tissues. In contrast, E-cadherin expression was reduced in ectopic pregnant fallopian tubes, possibly as a consequence of increased Wnt signaling. Moreover, glycogen accumulated in the tubal cells, and hyperplasia was observed in the tubal arteries with ectopic pregnancy, which is consistent with the effects induced by Wnt signaling and inflammation. All these changes could create the permissive environment that promotes embryos to ectopically implant into the fallopian tube.

LIMITATIONS, REASONS FOR CAUTION

This finding requires a further confirmation about what activates Wnt signaling in ectopic tubal pregnancies. Also, it is generally recognized that Chlamydia infection is associated with ectopic pregnancy, and disturbs tubal epithelia via the Wnt signaling. However, the infection type in the samples used was salpingitis.

WIDER IMPLICATIONS OF THE FINDINGS

A better understanding of the underlying mechanisms leading to ectopic pregnancies may contribute to our knowledge of the pathogenesis of tubal disorders and infertility and to the prevention of tubal ectopic pregnancy.

A critical regulatory role for macrophage migration inhibitory factor in hyperoxia-induced injury in the developing murine lung

BACKGROUND

The role and mechanism of action of MIF in hyperoxia-induced acute lung injury (HALI) in the newborn lung are not known. We hypothesized that MIF is a critical regulatory molecule in HALI in the developing lung.

METHODOLOGY

We studied newborn wild type (WT), MIF knockout (MIFKO), and MIF lung transgenic (MIFTG) mice in room air and hyperoxia exposure for 7 postnatal (PN) days. Lung morphometry was performed and mRNA and protein expression of vascular mediators were analyzed.

RESULTS

MIF mRNA and protein expression were significantly increased in WT lungs at PN7 of hyperoxia exposure. The pattern of expression of Angiopoietin 2 protein (in MIFKO>WT>MIFTG) was similar to the mortality pattern (MIFKO>WT>MIFTG) in hyperoxia at PN7. In room air, MIFKO and MIFTG had modest but significant increases in chord length, compared to WT. This was associated with decreased expression of Angiopoietin 1 and Tie 2 proteins in the MIFKO and MIFTG, as compared to the WT control lungs in room air. However, on hyperoxia exposure, while the chord length was increased from their respective room air controls, there were no differences between the 3 genotypes.

CONCLUSION

These data point to the potential roles of Angiopoietins 1, 2 and their receptor Tie2 in the MIF-regulated response in room air and upon hyperoxia exposure in the neonatal lung.

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

Endometriosis, a disease of reproductive age women, is a major cause of infertility, menstrual disorders and pelvic pain. Little is known about its etiopathology, but chronic pelvic inflammation is a common feature in affected women. Beside symptomatic treatment of endometriosis-associated pain, only two main suboptimal therapeutic approaches (hormonal and invasive surgery) are generally recommended to patients and no specific targeted treatment is available. Our studies led to the detection of a marked increase in the expression of macrophage migration inhibitory factor (MIF) in the eutopic endometrium, the peripheral blood and the peritoneal fluid of women with endometriosis, and in early, vascularized and active endometriotic lesions. Herein, we developed a treatment model of endometriosis, where human endometrial tissue was first allowed to implant into the peritoneal cavity of nude mice, to assess in vivo the effect of a specific antagonist of MIF (ISO-1) on the progression of endometriosis and evaluate its efficacy as a potential therapeutic tool. Administration of ISO-1 led to a significant decline of the number, size and in situ dissemination of endometriotic lesions. We further showed that ISO-1 may act by significantly inhibiting cell adhesion, tissue remodeling, angiogenesis and inflammation as well as by altering the balance of pro- and anti-apoptotic factors. Actually, mice treatment with ISO-1 significantly reduced the expression of cell adhesion receptors αv and ß3 integrins (P<0.05), matrix metalloproteinases (MMP) 2 and 9 (P<0.05), vascular endothelial cell growth factor (VEGF) (P<0.01), interleukin 8 (IL8) (P<0.05), cyclooxygenease (COX)2 (P<0.001) and the anti-apoptotic protein Bcl2 (P<0.01), but significantly induced the expression of Bax (P<0.05), a potent pro-apoptotic protein. These data provide evidence that specific inhibition of MIF alters endometriotic tissue growth and progression in vivo and may represent a promising potential therapeutic avenue.

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.

Diclofenac sodium inhibits NFkappaB transcription in osteoclasts

A non-steroidal anti-inflammatory drug, diclofenac, acts efficiently against inflammation; however, down-regulation of diclofenac on bone remodeling has raised concerns. The inhibitory mechanisms of diclofenac are poorly understood. We hypothesized that diclofenac down-regulates osteoclast differentiation and activation via inhibition of the translocation of phosphorylated nuclear factor kappa B (NFkappaB). When osteoclasts prepared from mouse hematopoietic stem cells were treated with diclofenac, tartrateresistant acid phosphatase-positive multinucleated cells decreased in a concentration-dependent manner. Pit formation assay revealed the abolition of osteoclastic bone resorption; levels of cathepsin K transcripts, an osteoclastic resorption marker, were down-regulated time-dependently. Diclofenac induced the accumulation of the inhibitor of kappa B in cytosol, which led to suppression of the nuclear translocation of NFkappaB and phosphorylated NFkappaB. These results suggest that the novel mechanism of diclofenac for bone remodeling is associated with phosphorylated NFkappaB reduction, which regulates osteoclast differentiation and activation.

Up-regulation of cyclooxygenase-2 expression and prostaglandin E2 production in human endometriotic cells by macrophage migration inhibitory factor: involvement of novel kinase signaling pathways

Cyclooxygenase (COX) is the rate-limiting enzyme in the metabolic conversion of arachidonic acid to prostaglandins (PGs), including prostaglandin E(2) (PGE(2)), a major mediator of inflammation and angiogenesis. Herein, we report that macrophage migration inhibitory factor (MIF), a potent proinflammatory and growth-promoting factor found at elevated concentrations in the peritoneal fluid of women with endometriosis and active endometriosis lesions, acts directly on ectopic endometrial cells to stimulate the synthesis of COX-2, the inducible form of COX, and the release of PGE(2). MIF treatment strongly activated p38 and ERK MAPK, and specific inhibitors of both pathways completely blocked basal and MIF-induced PGE(2) synthesis. Whereas p38 inhibitors negatively affected the stimulated synthesis of COX-2 and that of PGE(2), ERK inhibitors only decreased the production of PGE(2). These findings show for the first time a direct role for MIF in the up-regulation of COX-2 synthesis and PGE(2) secretion in ectopic endometrial cells. They further indicate that whereas p38 and ERK MAPK signaling pathways both play a significant role in the regulation of basal and MIF-induced synthesis of PGE(2) by ectopic endometrial cells, only p38 kinase is involved in the regulation of COX-2 expression in these cells. This suggests that MIF acts at more than one level to stimulate the synthesis of PGE(2) and triggers the coordinate activation of multiple enzymes in the biosynthesis pathway. Our data provide evidence for a novel mechanism by which MIF can induce a proinflammatory phenotype in ectopic endometrial cells, and favor the establishment of endometriosis and its related clinical symptoms.