Intracellular Macrophage Migration Inhibitory Factor Research Articles

Macrophage Migration Inhibitory Factor Promotes Thromboinflammation and Predicts Fast Progression of Aortic Stenosis.

Aortic stenosis (AS) is driven by progressive inflammatory and fibrocalcific processes regulated by circulating inflammatory and valve resident endothelial and interstitial cells. The impact of platelets, platelet-derived mediators, and platelet-monocyte interactions on the acceleration of local valvular inflammation and mineralization is presently unknown. We prospectively enrolled 475 consecutive patients with severe symptomatic AS undergoing aortic valve replacement. Clinical workup included repetitive echocardiography, analysis of platelets, monocytes, chemokine profiling, aortic valve tissue samples for immunohistochemistry, and gene expression analysis. The patients were classified as fast-progressive AS by the median ∆Vmax of 0.45 m/s per year determined by echocardiography. Immunohistological aortic valve analysis revealed enhanced cellularity in fast-progressive AS (slow- versus fast-progressive AS; median [interquartile range], 247 [142.3-504] versus 717.5 [360.5-1234]; P<0.001) with less calcification (calcification area, mm2: 33.74 [27.82-41.86] versus 20.54 [13.52-33.41]; P<0.001). MIF (macrophage migration inhibitory factor)-associated gene expression was significantly enhanced in fast-progressive AS accompanied by significantly elevated MIF plasma levels (mean±SEM; 6877±379.1 versus 9959±749.1; P<0.001), increased platelet activation, and decreased intracellular MIF expression indicating enhanced MIF release upon platelet activation (CD62P, %: median [interquartile range], 16.8 [11.58-23.8] versus 20.55 [12.48-32.28], P=0.005; MIF, %: 4.85 [1.48-9.75] versus 2.3 [0.78-5.9], P<0.001). Regression analysis confirmed that MIF-associated biomarkers are strongly associated with an accelerated course of AS. Our findings suggest a key role for platelet-derived MIF and its interplay with circulating and valve resident monocytes/macrophages in local and systemic thromboinflammation during accelerated AS. MIF-based biomarkers predict an accelerated course of AS and represent a novel pharmacological target to attenuate progression of AS.

Phosphorylation of MIF by PIP4K2a is necessary for cilia biogenesis

Primary cilia are microtubule-based organelles that play important roles in development and tissue homeostasis. Macrophage migration inhibitory factor (MIF) has long been recognized as a secreted cytokine in the pathogenesis of various human diseases, including cancer and autosomal dominant polycystic kidney disease (ADPKD). Unlike other cytokines, unique functional characteristics of intracellular MIF have emerged. In this study, we show that MIF is localized and formed a ring like structure at the proximal end of centrioles, where it regulates cilia biogenesis through affecting 1) the recruitment of TTBK2 to basal body and the removal of CP110 from mother centriole, 2) the accumulation of CEP290 at centriolar satellites, and 3) the trafficking of intraflagellar transport (IFT) related proteins. We also show that MIF functions as a novel transcriptional factor to regulate the expression of genes related to ciliogenesis via binding on the promotors of those genes. MIF also binds chromatin and regulates transcription of genes involved in diverse homeostatic signaling pathways. We identify phosphatidylinositol-5-phosphate 4-kinase type 2 alpha (PIP4K2a) as an upstream regulator of MIF, which interacts with and phosphorylates MIF at S91 to increase its interaction with 14-3-3ζ, resulting in its nuclear translocation and transcription regulation. This study suggests that MIF is a key player in cilia biogenesis and a novel transcriptional regulator in homeostasis, which forward our understanding of how MIF is able to carry out several nonoverlapping functions.

Macrophage migration inhibitory factor (MIF) promotes intervertebral disc degeneration through the NF-κB pathway, and the MIF inhibitor CPSI-1306 alleviates intervertebral disc degeneration in a mouse model.

Lumbar intervertebral disc degeneration(IDD) is a prevalent inflammatory disease caused by many proinflammatory factors, such as TNF and IL-1β. Migration inhibitory factor (MIF) is an upstream inflammatory factor widely expressed invivo that is associated with a variety of inflammatory diseases or malignant tumors and has potential therapeutic value in many diseases. We explored the role of MIF in intervertebral disc degeneration by regulating the content of exogenous MIF or the expression of MIF in cells. Upon inducing degeneration of nucleus pulposus (NP) cells with IL-1β, we found that the increase in intracellular and exogenous MIF promoted the catabolism induced by proinflammatory factors in NP cells, while silencing of the MIF gene alleviated the degeneration to some extent. In a mouse model, the intervertebral disc degeneration of MIF-KO mice was significantly less than that of wild-type mice. To explore the treatment of intervertebral disc degeneration, we selected the small-molecular MIF inhibitor CPSI-1306. CPSI-1306 had a therapeutic effect on intervertebral disc degeneration in the mouse model. In summary, we believe that MIF plays an important role in intervertebral disc degeneration and is a potential therapeutic target for the treatment of intervertebral disc degeneration.

Extracellular macrophage migration inhibitory factor (MIF) downregulates adipose hormone-sensitive lipase (HSL) and contributes to obesity

Attenuation of adipose hormone sensitive lipase (HSL) may impair lipolysis and exacerbate obesity. We investigate the role of cytokine, macrophage migration inhibitory factor (MIF) in regulating adipose HSL and adipocyte hypertrophy. Extracellular MIF downregulates HSL in an autocrine fashion, by activating the AMPK/JNK signaling pathway upon binding to its membrane receptor, CD74. WT mice fed high fat diet (HFD), as well as mice overexpressing MIF, both had high circulating MIF levels and showed suppression of HSL during the development of obesity. Blocking the extracellular action of MIF by a neutralizing MIF antibody significantly reduced obesity in HFD mice. Interestingly, intracellular MIF binds with COP9 signalosome subunit 5 (Csn5) and JNK, which leads to an opposing effect to inhibit JNK phosphorylation. With global MIF deletion, adipocyte JNK phosphorylation increased, resulting in decreased HSL expression, suggesting that the loss of MIF's intracellular inhibitory action on JNK was dominant in Mif−/− mice. Adipose tissue from Mif−/− mice also exhibited higher Akt and lower PKA phosphorylation following HFD feeding compared with WT, which may contribute to the downregulation of HSL activation during more severe obesity. Both intracellular and extracellular MIF have opposing effects to regulate HSL, but extracellular actions predominate to downregulate HSL and exacerbate the development of obesity during HFD.

Activity-Based Imaging of Macrophage Migration Inhibitory Factor with a Two-Photon Fluorescent Probe.

Macrophage migration inhibitory factor (MIF), as a cytokine, plays an important role in the pathogenesis of cancer and some other diseases, and it is also one of the potential drug targets for disease treatment. However, due to the lack of simple and effective MIF imaging detection tools, the fluctuation and distribution of MIF in living cells or at lesion sites remain difficult to track precisely and in real time. Here, we report activity-based fluorescent probes, named MIFP1-MIFP3, which are used for real-time imaging and tracking of intracellular MIF, thus establishing a relationship between the fluctuation of MIF and the change of fluorescence signal during the cancer disease process. With the excellent optical properties of two-photon probe imaging, we can easily distinguish multiple cancer cells from normal cells with the representative probe, MIFP3. Moreover, MIFP3 has also been successfully used to directly identify the pathological tissues of patients with clinical liver cancer. These potential MIF probes could provide powerful tools for further study of the physiological function of MIF and will be helpful to promote the accurate diagnosis and therapeutic evaluation of MIF-associated malignancies.

The inhibitory effects of MIF on accumulation of canine degenerative myelopathy-associated mutant SOD1 aggregation

Canine degenerative myelopathy (DM) is a progressive neurodegenerative disorder, which is commonly associated with c.118G > A (p. E40K) missense mutation in the superoxide dismutase 1 (SOD1) gene. Mutant SOD1 protein (SOD1E40K) is likely to be misfolded, acquire insolubility, aggregate in the cytoplasm of neural cells, and lead to degeneration of the nervous tissues. Along with a chaperone activity, macrophage migration inhibitory factor (MIF) is a multifunctional protein that has been shown to directly inhibit human mutant SOD1 misfolding and enhance survival of mutant SOD1-expressing motor neurons. The purpose of this study was to determine whether MIF also inhibits DM-related SOD1E40K misfolding and accumulation of SOD1 aggregates.Human embryonic kidney 293A cells were transfected SOD1cWT or SOD1E40K with or without MIF. The percentages of cells containing transfected SOD1 aggregates were measured by immunocytochemistry, and the amount of SOD1E40K in the insoluble fraction was evaluated by immunoblotting. The percentage of cells with SOD1E40K aggregates and the amount of insoluble SOD1E40K protein decreased in the presence of MIF. Because the chaperone activity of MIF assists in SOD1E40K folding and enhances the refolding and degradation of misfolded SOD1E40K, the results of this study suggests that MIF regulates the accumulation of SOD1 aggregates by its chaperone activity. We propose that enhancing intracellular MIF chaperone activity could be an effective therapeutic strategy for DM.

Targeting Macrophage Migration Inhibitory Factor in Acute Pancreatitis and Pancreatic Cancer.

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine implicated in the pathogenesis of inflammation and cancer. It is produced by various cells and circulating MIF has been identified as a biomarker for a range of diseases. Extracellular MIF mainly binds to the cluster of differentiation 74 (CD74)/CD44 to activate downstream signaling pathways. These in turn activate immune responses, enhance inflammation and can promote cancer cell proliferation and invasion. Extracellular MIF also binds to the C-X-C chemokine receptors cooperating with or without CD74 to activate chemokine response. Intracellular MIF is involved in Toll-like receptor and inflammasome-mediated inflammatory response. Pharmacological inhibition of MIF has been shown to hold great promise in treating inflammatory diseases and cancer, including small molecule MIF inhibitors targeting the tautomerase active site of MIF and antibodies that neutralize MIF. In the current review, we discuss the role of MIF signaling pathways in inflammation and cancer and summarize the recent advances of the role of MIF in experimental and clinical exocrine pancreatic diseases. We expect to provide insights into clinical translation of MIF antagonism as a strategy for treating acute pancreatitis and pancreatic cancer.

In Vivo Imaging of the Macrophage Migration Inhibitory Factor in Liver Cancer with an Activity-Based Probe.

The macrophage migration inhibitory factor (MIF), a vital cytokine and biomarker, has been suggested to closely associate with the pathogenesis of liver cancer. However, a simple and effective approach for monitoring the change and distribution of cellular MIF is currently lacking and urgently needed, which could be helpful for a better understanding of its role in the progression of cancer. Herein, we report a novel activity-based probe, TPP2, which allows for direct labeling and imaging of endogenous MIF activity within live cells, clinical tissues, and in vivo in a mouse model of liver cancer. With this probe, we have intuitively observed the dynamic change of intracellular MIF activity by both flow cytometry and confocal imaging. We further found that TPP2 permits the identification and distinguishing of liver cancer in vitro and in vivo with high sensitivity and selectivity toward MIF. Our observations indicate that TPP2 could provide a promising new imaging approach for elucidating the MIF-related biological functions in liver cancer.

Revisiting the secretion mechanism(s) of macrophage migration inhibitory factor-welcome to the "UPS club".

Revisiting the secretion mechanism(s) of macrophage migration inhibitory factor-welcome to the "UPS club".

Cross-kingdom mimicry of the receptor signaling and leukocyte recruitment activity of a human cytokine by its plant orthologs

Cross-kingdom mimicry of the receptor signaling and leukocyte recruitment activity of a human cytokine by its plant orthologs

Obacunone causes sustained expression of MKP-1 thus inactivating p38 MAPK to suppress pro-inflammatory mediators through intracellular MIF.

Obacunone (OBA) is a highly oxygenated triterpenoid with various pharmacological activities. In this study, we explored its anti-inflammatory effect and underlying mechanisms in LPS-activated macrophages. Our data showed that OBA potently decreased pro-inflammatory mediators (eg, NO, IL-6, IL-1β, and MCP-1) at the transcriptional and translational levels without cytotoxicity. A mechanism study showed that OBA significantly suppressed p38-mediated AP-1 signaling by stabilizing the mRNA of mitogen-activated protein kinase phosphatase 1 (MKP-1), thus prolonging the expression time of the MKP-1 protein. Next, we used computational target-fishing technology to predict the possible target of OBA. Only one potential target, macrophage migration inhibitory factor (MIF), was presented. Experimentally, the interaction between OBA and MIF was also confirmed. By using an anti-mouse MIF antibody, extracellular MIF (exMIF) was neutralized. Our results showed that autocrine MIF had slight influence on the pro-inflammatory mediator production. Correspondingly, the anti-inflammatory activity of OBA was also not affected. Accordingly, we knocked down the MIF gene in RAW 264.7 cells and obtained stable MIF deficient cells MIF(-), in which the effects of OBA on p38 phosphorylation, AP-1 activation, and pro-inflammatory mediator production in response to LPS nearly disappeared. In contrast to MIF(+) cells, the MKP-1 protein expression time of the MIF(-) cells was markedly prolonged. We conclude that OBA exerts its anti-inflammatory effect by targeting intracellular MIF (inMIF) inhibition to regulate the MKP-1/p38/AP-1 pathway. Our findings also provide a chain of evidence that the inhibition of inMIF, rather than exMIF, may become a novel target for inflammation.

Macrophage migration inhibitory factor interacts with thioredoxin-interacting protein and induces NF-κB activity

The nuclear factor kappa B (NF-κB) pathway is pivotal in controlling survival and apoptosis of cancer cells. Macrophage migration inhibitory factor (MIF), a cytokine that regulates the immune response and tumorigenesis under inflammatory conditions, is upregulated in various tumors. However, the intracellular functions of MIF are unclear. In this study, we found that MIF directly interacted with thioredoxin-interacting protein (TXNIP), a tumor suppressor and known inhibitor of NF-κB activity, and MIF significantly induced NF-κB activation. MIF competed with TXNIP for NF-κB activation, and the intracellular MIF induced NF-κB target genes, including c-IAP2, Bcl-xL, ICAM-1, MMP2 and uPA, by inhibiting the interactions between TXNIP and HDACs or p65. Furthermore, we identified the interaction motifs between MIF and TXNIP via site-directed mutagenesis of their cysteine (Cys) residues. Cys57 and Cys81 of MIF and Cys36 and Cys120 of TXNIP were responsible for the interaction. MIF reversed the TXNIP-induced suppression of cell proliferation and migration. Overall, we suggest that MIF induces NF-κB activity by counter acting the inhibitory effect of TXNIP on the NF-κB pathway via direct interaction with TXNIP. These findings reveal a novel intracellular function of MIF in the progression of cancer.

Targeted intracellular accumulation of macrophage migration inhibitory factor in the reperfused heart mediates cardioprotection.

S-nitrosation of macrophage migration inhibitory factor (MIF) has been shown to be cytoprotective in myocardial ischaemia/reperfusion (I/R) injury. Since the exact mechanism of action is unknown, we here characterise the cardioprotective effects of targeted intracellular accumulation of MIF in myocardial I/R injury. We used different in vivo, ex vivo and in vitro models of myocardial I/R and hypoxia/reoxygenation (H/R) injury to determine MIF levels by immunoblots and ELISA in different phases of reperfusion and reoxygenation, respectively. We discovered a rapid decrease of cardiac MIF that was specific to the early phase of reperfusion. Posttranslational modification of MIF via S-nitrosation--proofed by a modified version of the Biotin Switch Assay--prevented this rapid decrease, leading to a targeted intracellular accumulation of MIF in the early phase of reperfusion. Intracellular MIF accumulation preserved the intracellular ability of MIF to reduce oxidative stress as shown by hydrogen peroxide and aconitase activity measurements. Infarct size measurements by TTC staining showed an overall enhanced cardioprotective effect of this protein by reduction of reperfusion injury. In summary, we have unravelled a novel mechanism of MIF-mediated cardioprotection. Targeted intracellular accumulation of MIF by S-nitrosation may offer a novel therapeutic approach in the treatment of myocardial I/R-injury.

Macrophage Migration Inhibitory Factor as a Chaperone Inhibiting Accumulation of Misfolded SOD1

Mutations in superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by loss of motor neurons and accompanied by accumulation of misfolded SOD1 onto the cytoplasmic faces of intracellular organelles, including mitochondria and the endoplasmic reticulum (ER). Using inhibition of misfolded SOD1 deposition onto mitochondria as an assay, a chaperone activity abundant in nonneuronal tissues is now purified and identified to be the multifunctional macrophage migration inhibitory factor (MIF), whose activities include an ATP-independent protein folding chaperone. Purified MIF is shown to directly inhibit mutant SOD1 misfolding. Elevating MIF in neuronal cells suppresses accumulation of misfolded SOD1 and its association with mitochondria and the ER and extends survival of mutant SOD1-expressing motor neurons. Accumulated MIF protein is identified to be low in motor neurons, implicating correspondingly low chaperone activity as a component of vulnerability to mutant SOD1 misfolding and supporting therapies to enhance intracellular MIF chaperone activity.

Macrophage migration inhibitory factor counter‐regulates dexamethasone‐induced annexin 1 expression and influences the release of eicosanoids in murine macrophages

Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine and glucocorticoid (GC) counter-regulator, has emerged as an important modulator of inflammatory responses. However, the molecular mechanisms of MIF counter-regulation of GC still remain incomplete. In the present study, we investigated whether MIF mediated the counter-regulation of the anti-inflammatory effect of GC by affecting annexin 1 in RAW264.7 macrophages. We found that stimulation of RAW264.7 macrophages with lipopolysaccharide (LPS) resulted in down-regulation of annexin 1, while GC dexamethasone (Dex) or Dex plus LPS led to significant up-regulation of annexin 1 expression. RNA interference-mediated knockdown of intracellular MIF increased annexin 1 expression with or without incubation of Dex, whereas Dex-induced annexin 1 expression was counter-regulated by the exogenous application of recombinant MIF. Moreover, recombinant MIF counter-regulated, in a dose-dependent manner, inhibition of cytosolic phospholipase A2α (cPLA2α) activation and prostaglandin E2 (PGE2 ) and leukotriene B4 (LTB4 ) release by Dex in RAW264.7 macrophages stimulated with LPS. Endogenous depletion of MIF enhanced the effects of Dex, reflected by further decease of cPLA2α expression and lower PGE2 and LTB4 release in RAW264.7 macrophages. Based on these data, we suggest that MIF counter-regulates Dex-induced annexin 1 expression, further influencing the activation of cPLA2α and the release of eicosanoids. These findings will add new insights into the mechanisms of MIF counter-regulation of GC.

P14: Time dependent regulation of MIF by S-nitros(yl)ation reduces apoptosis in myocardial I/R-injury

Background Macrophage migration inhibitory factor (MIF) is cardioprotective in myocardial ischemia/reperfusion (I/R) injury. MIF reduces apoptosis by its extracellular chemokine-like functions and the inhibition of the JNK pathway via intracellular JAB 1 binding. Unbound intracellular MIF reduces oxidative stress via its oxidoreductase activity. S -Nitros(yl)ation of MIF after nitrite application in I/R injury is a phenomenon of the early phase of reperfusion. S -Nitros(yl)ation enhances MIF’s cardioprotective properties: increase of the enzyme-like activity, reduction of infarct sizes and apoptosis. S -Nitros(yl)ation of MIF and MIF/JAB 1 interaction both depend on MIF’s cysteine 81. Whether S -nitros(yl)ation of MIF influences MIF/JAB 1 interaction during different phases of reperfusion and whether this affects MIF’s intra-and extracellular properties, is unclear. Hypothesis S -Nitros(yl)ation of MIF regulates its binding to JAB 1, its localization and its consecutive signaling pathways differentially in the various phases of reperfusion. Methods/Results TUNEL staining of murine hearts after in vivo I/R injury showed reduced apoptosis after S -nitros(yl)ation of MIF (14.5 ± 1.0% vs. 8.0 ± 3.5%, p In early phase of reperfusion, MIF/JAB 1 interaction was reduced upon S -nitros(yl)ation (0.3 ± 0.06% vs. 0.11 ± 0.04%, n = 4, p n = 5). Intracellular MIF protects from ROS induced damage: aconitase acitivity was higher after S -nitros(yl)ation than in control (2.1 ± 0.5 mU/mg protein vs. 1.25 ± 0.5 mU/mg protein, n = 3, p After 4 h of reperfusion, S -nitros(yl)ation and its effect on MIF/JAB 1 interaction was vanished: MIF/JAB 1 interaction was not different in both groups (0.34 ± 0.09% vs. 0.32 ± 0,05%, n = 5, p = ns). MIF concentrations in coronary effluent were higher after S -nitros(yl)ation than in control (4.9 ± 2 ng/min/g heart vs. 0.7 ± 0.3 ng/min/g heart, n = 5) showing time-delayed MIF release. Conclusion S -Nitros(yl)ation of MIF in I/R-injury reduces the MIF/JAB 1 interaction and MIF’s secretion. This detains MIF in the cell during early phase of reperfusion, where MIF reduces oxidative stress. In late phase-when S -nitros(yl)ation of MIF has vanished-MIF is released to the extracellular space, where other signaling pathways can be activated. Disclosure Nothing to disclose.

Release of macrophage migration inhibitory factor by neuroendocrine-differentiated LNCaP cells sustains the proliferation and survival of prostate cancer cells

The acquisition of neuroendocrine (NE) characteristics by prostate cancer (PCa) cells is closely related to tumour progression and hormone resistance. The mechanisms by which NE cells influence PCa growth and progression are not fully understood. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine involved in oncogenic processes, and MIF serum levels correlate with aggressiveness of PCa. Here, we investigated the regulation and the functional consequences of MIF expression during NE transdifferentiation of PCa cells. NE differentiation (NED) of LNCaP cells, initiated either by increasing intracellular levels of cAMP or by culturing cells in an androgen-depleted medium, was associated with markedly increased MIF release. Yet, intracellular MIF protein and mRNA levels and MIF gene promoter activity decreased during NED of LNCaP cells, suggesting that NED favours MIF release despite decreasing MIF synthesis. Adenoviral-mediated forced MIF expression in NE-differentiated LNCaP cells increased cell proliferation without affecting the expression of NE markers. Addition of exogenous recombinant MIF to LNCaP and PC-3 cells stimulated the AKT and ERK1/2 signalling pathways, the expression of genes involved in PCa, as well as proliferation and resistance to paclitaxel and thapsigargin-induced apoptosis. Altogether, these data provide evidence that increased MIF release during NED in PCa may facilitate cancer progression or recurrence, especially following androgen deprivation. Thus, MIF could represent an attractive target for PCa therapy.

Inhibiting the HSP90 chaperone destabilizes macrophage migration inhibitory factor and thereby inhibits breast tumor progression

Intracellular macrophage migration inhibitory factor (MIF) often becomes stabilized in human cancer cells. MIF can promote tumor cell survival, and elevated MIF protein correlates with tumor aggressiveness and poor prognosis. However, the molecular mechanism facilitating MIF stabilization in tumors is not understood. We show that the tumor-activated HSP90 chaperone complex protects MIF from degradation. Pharmacological inhibition of HSP90 activity, or siRNA-mediated knockdown of HSP90 or HDAC6, destabilizes MIF in a variety of human cancer cells. The HSP90-associated E3 ubiquitin ligase CHIP mediates the ensuing proteasome-dependent MIF degradation. Cancer cells contain constitutive endogenous MIF-HSP90 complexes. siRNA-mediated MIF knockdown inhibits proliferation and triggers apoptosis of cultured human cancer cells, whereas HSP90 inhibitor-induced apoptosis is overridden by ectopic MIF expression. In the ErbB2 transgenic model of human HER2-positive breast cancer, genetic ablation of MIF delays tumor progression and prolongs overall survival of mice. Systemic treatment with the HSP90 inhibitor 17AAG reduces MIF expression and blocks growth of MIF-expressing, but not MIF-deficient, tumors. Together, these findings identify MIF as a novel HSP90 client and suggest that HSP90 inhibitors inhibit ErbB2-driven breast tumor growth at least in part by destabilizing MIF.

Macrophage migration inhibitory factor, Toll-like receptor 4, and CD14 polymorphisms with altered expression levels in patients with ulcerative colitis

Ulcerative colitis is a multifactorial disease in which genetic factors play a major role. Functional mutations in the genes related to innate immune response exacerbate mucosal damage coupled with persistent inflammation. The cytokine macrophage migration inhibitory factor (MIF), CD14, and Toll-like receptor 4 (TLR4) are the central players with clearly defined roles in inflammation. The aim of this study was to investigate the association between MIF-173G > C, CD14-159C > T, and TLR4-299A > G polymorphisms and mononuclear cell expression in patients with ulcerative colitis (UC). Genotyping of MIF-173G > C, CD14-159C > T, and TLR4-299A > G polymorphisms was performed by amplification refractory mutation system-polymerase chain reaction and allele-specific amplification in 139 and 176 patients with UC and controls, respectively. Simultaneously, the expression levels of intracellular MIF, mCD14, and mTLR4 were determined in mononuclear cells using a flow cytometer. Polymorphisms in CD14-159C > T and TLR4-299A > G significantly affected mCD14 and mTLR4 expression levels and also increased susceptibility to UC. Although intracellular MIF expression levels differed among patient and control groups, the polymorphism in MIF 173G > C was not observed to be associated with a risk of UC.

Macrophage Migration Inhibitory Factor Provides Cardioprotection During Ischemia/Reperfusion by Reducing Oxidative Stress

Macrophage migration inhibitory factor (MIF) is a multifunctional protein that exhibits an intrinsic thiol protein oxidoreductase activity and proinflammatory activities. In the present study to examine intracellular MIF redox function, exposure of MIF-deficient cardiac fibroblasts to oxidizing conditions resulted in a 2.3-fold increase (p < 0.001) in intracellular ROS that could be significantly reduced by adenoviral-mediated reexpression of recombinant MIF. In an animal model of myocardial injury by ischemia/reperfusion (I/R), MIF-deficient hearts exhibited higher levels of oxidative stress than did wild-type hearts, as measured by significantly higher oxidized glutathione levels (decreased GSH/GSSG ratio), increased protein oxidation, reduced aconitase activity, and increased mitochondrial injury (increased cytochrome c release). The increased myocardial oxidative stress after I/R was reflected by larger infarct size (INF) in MIF-deficient hearts versus wild-type (WT) hearts (21 ± 6% vs. 8 ± 3% INF/LV; p < 0.05). In vivo hemodynamic measurements showed that left ventricular (LV) contractile function of MIF-deficient hearts subjected to 15-min ischemia failed to recover during reperfusion compared with WT hearts (LV developed pressure and ± dP/dt; p = 0.02). These data represent the first in vivo evidence in support of a cardioprotective role of MIF in the postischemic heart by reducing oxidative stress.