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Macrophage migration inhibitory factor in systemic lupus erythematosus.

OBJECTIVE: To examine associations between serum macrophage migration inhibitory factor (MIF) and disease-related variables and corticosteroid use in patients with systemic lupus erythematosus (SLE). METHODS: Serum MIF concentration was measured by ELISA in 90 female patients with SLE and 279 healthy controls. Univariate and multivariate regression analyses were used to examine the associations between serum MIF concentration and disease-related indices of SLE and corticosteroid use. RESULTS: Serum MIF concentrations were positively associated with SLE disease damage (SLICC/ACR index), and indices of disease damage were greater in SLE patients with serum MIF concentrations above the normal median value. Serum MIF concentration was also observed to be significantly greater in patients with SLICC/ACR damage index (DI) scores >/= 3. Serum MIF was also positively associated with current corticosteroid dose. Significantly higher SLICC/ACR DI scores were observed in patients with values of serum MIF above the normal median, and this remained significant after adjusting for corticosteroid dose. Serum MIF concentration was also predictive of SLICC/ACR index after 3 years of followup, but this association was partly confounded by corticosteroid dose. Serum MIF was also negatively associated with serum creatinine concentration, independent of disease damage and corticosteroid dose. CONCLUSION: MIF is overexpressed in patients with SLE. While this can be partly explained by corticosteroid use, there is evidence of an association between MIF and lupus-related disease damage.

Adolescent↗

Macrophage migration inhibitory factor promotes tumor invasion and metastasis via the Rho-dependent pathway.

PURPOSE: Macrophage migration inhibitory factor (MIF) plays an important role not only in the immune system but also in tumorigenesis. In this study, we investigated the potential role of MIF in association with tumor invasion and metastasis. METHODS: To assess the function of MIF, we knocked down the MIF mRNA using small interfering RNA (siRNA). Twenty-one base siRNA specific for the mRNA sequence of mouse MIF was introduced to a murine colon cancer cell line, colon 26. Tumor cell invasion was evaluated using a transwell method (8-microm pores) coated with Matrigel on the upperside membrane and with fibronectin on the underside membrane. Moreover, we investigated the signal transduction of lysophosphatidic acid (LPA) relevant to the Rho-dependent pathway and further examined the effect of MIF siRNA on this signal transduction system. In vivo, the tumor cells were pretreated with MIF siRNA and injected into the portal vein, and the effects on metastasis to the liver were evaluated. RESULTS: We found that MIF siRNA markedly reduced the invasion of the cells from the upperside to lowerside membranes. We revealed that the Rho-dependent pathway activated by LPA was suppressed by MIF siRNA. Next, we found that the tyrosine-phosphorylation of focal adhesion kinase and LPA-induced expressions of integrin beta1 were significantly suppressed by MIF siRNA. In vivo, metastasis to the liver was significantly inhibited by pretreatment of the cells with MIF siRNA. CONCLUSION: Taken together, these results suggest that MIF promotes tumor invasion and metastasis via the Rho-dependent pathway.

Animals↗

Mutation screening of the macrophage migration inhibitory factor gene: positive association of a functional polymorphism of macrophage migration inhibitory factor with juvenile idiopathic arthritis.

OBJECTIVE: To determine if polymorphisms of the macrophage migration inhibitory factor (MIF) gene are associated with juvenile idiopathic arthritis (JIA). METHODS: Denaturing high-performance liquid chromatography was used to screen the MIF gene in 32 UK Caucasian controls and 88 UK Caucasian JIA patients. Ninety-two healthy UK Caucasian controls were then genotyped for each of the polymorphic positions identified. A panel of 526 UK Caucasian JIA patients and 259 UK Caucasian controls were subsequently genotyped for a single-nucleotide polymorphism (SNP) identified in the 5'-flanking region of the gene, using SNaPshot ddNTP primer extension and capillary electrophoresis. The functional significance of this polymorphism was also studied using luciferase-based reporter gene assays in human T lymphoblast and epithelial cell lines. RESULTS: A tetranucleotide repeat CATT((5-7)) beginning at nucleotide position -794 and 3 SNPs at positions -173 (G to C), +254 (T to C), and +656 (C to G) of the MIF gene were identified. No JIA-specific mutations were found. Allele and genotype frequencies differed significantly between the controls and the JIA patients for the MIF-173 polymorphism. Individuals possessing a MIF-173*C allele had an increased risk of JIA (34.8% versus 21.6%) (odds ratio 1.9, 95% confidence interval 1.4-2.7; P = 0.0002). Furthermore, the MIF-173* G and C variants resulted in altered expression of MIF in a cell type-specific manner. Serum levels of MIF were also significantly higher in individuals who carried a MIF-173*C allele (P = 0.04). CONCLUSION: The -173-MIF*C allele confers increased risk of susceptibility to JIA. Our data suggest a cell type-specific regulation of MIF, which may be central to understanding its role in inflammation.

Alleles↗

Regulation of p53 by macrophage migration inhibitory factor in inflammatory arthritis.

OBJECTIVE: To study the capacity of macrophage migration inhibitory factor (MIF) to regulate proliferation, apoptosis, and p53 in an animal model of rheumatoid arthritis (RA) and in fibroblast-like synoviocytes (FLS) from humans with RA. METHODS: Antigen-induced arthritis (AIA) was induced in MIF(-/-) mice and littermate controls. FLS were obtained from patients with RA. Western blotting and immunohistochemistry were used to measure p53 in cells and tissues. Apoptosis was detected in cells by flow cytometry using TUNEL and annexin V/propidium iodide labeling. Apoptosis in tissue was detected using TUNEL. Proliferation was assessed in cultured cells and tissue by (3)H-thymidine incorporation and Ki-67 immunostaining, respectively. RESULTS: MIF inhibited p53 expression in human RA FLS. Levels of p53 were correspondingly increased in MIF(-/-) mouse tissues and cells. Spontaneous and sodium nitroprusside-induced apoptosis were significantly increased in MIF(-/-) cells. In vitro exposure of FLS to MIF reduced apoptosis and significantly induced FLS proliferation. Synoviocyte proliferation in MIF(-/-) mice was correspondingly reduced. A decrease in the severity of AIA in MIF(-/-) mice was associated with an increase in p53 and apoptosis in synovium. Evidence of in situ proliferation was scant in this model, and no difference in in situ proliferation was detectable in MIF(-/-) mice compared with wild-type mice. CONCLUSION: These results indicate a role for MIF in the regulation of p53 expression and p53-mediated events in the inflamed synovium and support the hypothesis that MIF is of critical importance in the pathogenesis of RA.

Animals↗

Macrophage migration inhibitory factor up-regulates the expression of interleukin-8 messenger RNA in synovial fibroblasts of rheumatoid arthritis patients: common transcriptional regulatory mechanism between interleukin-8 and interleukin-1beta.

OBJECTIVE: Interleukin-8 (IL-8) plays an important role in the migration of inflammatory cells into the synovium and joint fluids in rheumatoid arthritis (RA). This study was undertaken to investigate the IL-8 inductive activity of the macrophage migration inhibitory factor (MIF) in RA synovial fibroblasts. The regulatory mechanism of IL-8 was compared with that of IL-1beta. METHODS: MIF-induced IL-8 and IL-1beta transcriptional activation was studied in RA synovial fibroblasts by Northern blot analysis, enzyme-linked immunosorbent assay, and electromobility shift assay. The effect of anti-MIF antibody administration on murine passive collagen-induced arthritis (CIA) was also evaluated by histologic examination and reverse transcriptase-polymerase chain reaction. RESULTS: MIF up-regulated the IL-8 messenger RNA (mRNA) and protein levels in a dose-dependent manner. The IL-8 mRNA up-regulation started 1 hour poststimulation by MIF, and reached a maximum level at 6 hours. IL-1beta mRNA was also up-regulated by MIF. The mRNA up-regulation of IL-8 and IL-1beta by MIF was inhibited by 2 tyrosine kinase inhibitors, a protein kinase C (PKC) inhibitor, an activator protein 1 (AP-1) inhibitor, and by an NF-kappaB inhibitor. A cAMP-dependent kinase inhibitor did not inhibit it. MIF enhanced AP-1 and NF-kappaB binding activities in a dose-dependent manner. Passive CIA enhanced mRNA levels of macrophage inflammatory protein 2 and cytokine-induced neutrophil chemoattractants and, moreover, migration and proliferation of inflammatory cells within the synovium, which were suppressed by administration of an anti-MIF antibody. CONCLUSION: MIF may play an important role in the migration of inflammatory cells into the synovium of rheumatoid joints via induction of IL-8. MIF up-regulates IL-8 and IL-1beta mRNA via tyrosine kinase-, PKC-, AP-1-, and NF-kappaB-dependent pathways.

Arthritis, Rheumatoid↗

Reduced leukocyte-endothelial cell interactions in the inflamed microcirculation of macrophage migration inhibitory factor-deficient mice.

OBJECTIVE: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with established roles in a range of inflammatory conditions. However, it is not known whether MIF influences inflammation via the direct promotion of leukocyte-endothelial cell interactions. Therefore, the aim of these experiments was to investigate the ability of MIF to regulate leukocyte-endothelial cell interactions in the inflamed microvasculature. METHODS: Intravital microscopy was used to examine postcapillary venules in the cremaster muscle and synovium of wild-type and MIF(-/-) mice. Leukocyte-endothelial cell interactions (rolling, adhesion, emigration) were compared under a range of inflammatory conditions. RESULTS: In cremasteric postcapillary venules of MIF(-/-) mice, lipopolysaccharide (LPS)-induced leukocyte rolling, adhesion, and emigration were significantly reduced relative to that in wild-type mice. Similar responses were observed in response to tumor necrosis factor alpha and histamine. Examination of the synovial microvasculature following exposure to carrageenan revealed that leukocyte rolling and adhesion in synovial postcapillary venules and leukocyte entry into the joint space were also reduced significantly in MIF(-/-) mice. In each of these models, the level of P-selectin-dependent rolling was reduced in MIF(-/-) mice. Despite this, no difference in P-selectin expression was observed following LPS treatment. However, microvascular shear forces were elevated in MIF(-/-) mice, raising a possible mechanism to explain the reduced interactions in these animals. CONCLUSION: MIF(-/-) mice consistently displayed a reduction in P-selectin-dependent rolling, suggesting that MIF exerts proinflammatory effects, in part, via the promotion of P-selectin-mediated rolling. Together, these data indicate that MIF promotes interactions between leukocytes and endothelial cells, thereby enhancing the entry of leukocytes into sites of inflammation.

Animals↗

Regulation of Toll-like receptor 4 expression in mouse colon by macrophage migration inhibitory factor.

Recent studies have indicated that macrophage migration inhibitory factor (MIF) and Toll-like receptor (TLR) play an important role in the regulation of innate immune responses. In this study, we investigated the effect of MIF on the expression of TLR4, a receptor that recognizes lipopolysaccharide, in colon using MIF-deficient mice. TLR4 mRNA expression in the colon tissues was determined by northern blot analysis. Western blot analysis and immunohistochemistry in the colon tissues were performed to evaluate the expression of TLR4 protein. The expressions of TLR4 mRNA and protein were remarkably down-regulated in colon tissues of MIF-deficient mice compared with wild-type mice and up-regulated by treatment with recombinant MIF. Immunohistochemical study revealed the presence of TLR4-positive staining in mononuclear cells in the lamina propria and intraepithelial mononuclear cells as well as weak staining in epithelial cells and crypts in colon tissues of wild-type mice. In contrast, MIF-deficient mice did not show TLR4-positive staining in the colonic mucosa. In MIF-deficient mice injected with recombinant mouse MIF (rMIF), TLR4-positive staining cells were observed in colon tissues similar to the findings in wild-type mice. Administration of dextran sulfate sodium (DSS) up-regulated the expression of TLR4 in the colons of WT mice but not in those of MIF-deficient mice. Furthermore, pretreatment with rMIF up-regulated the expression of TLR4 in response to DSS in MIF-deficient mice. Our results suggest that MIF affects the expression of TLR4 in mouse colon under both normal and colitic conditions.

Animals↗

A single nucleotide polymorphism of macrophage migration inhibitory factor is related to inflammatory response in coronary bypass surgery using cardiopulmonary bypass.

OBJECTIVE: Cardiac surgery causes induction and release of inflammatory mediators that may be regulated by genetic background. Macrophage migration inhibitory factor (MIF) is a proinflammatory mediator that is known to be up-regulated in patients undergoing cardiac operations. Here we analyzed genotype distribution and allele frequency of the MIF-173*G/C single nucleotide polymorphism (SNP) and MIF plasma levels in patients undergoing surgical revascularization with (on-pump, n=45) and without (off-pump, n=34) cardiopulmonary bypass (CPB). METHODS: Genotyping was performed using a real-time PCR-based system with a hybridization probe system specific for the MIF-173*G/C SNP. In on-pump patients, blood samples were drawn before start of CPB, after termination of CPB and 12h postoperatively. In off-pump patients, blood samples were collected before stabilizer placement, after removal of the stabilizer and 12h postoperatively. MIF levels were measured using ELISA technique. RESULTS: Genotype distribution and allele frequencies were comparable between on-pump and off-pump patients. When comparing patients according to MIF genotype, a significant increase of MIF plasma levels after completed coronary bypass grafting using CPB was found in patients heterozygous for the MIF-173*G/C SNP (p<0.05). Moreover, on-pump patients showed significantly decreased MIF plasma levels after 12h postoperatively (p<0.05). In off-pump patients, MIF plasma levels were not significantly different over the time-course and were independent of the genotype. CONCLUSIONS: Patients carrying the C-allele showed significantly increased levels of the proinflammatory cytokine MIF compared to G/G homozygous when revascularization was carried out using CPB. The G/C genotype may be associated with a severe inflammatory reaction and therefore preoperative screening could be beneficial for patients undergoing cardiac surgery using CPB.

Adult↗

Characterisation of macrophage migration inhibitory factor from Eimeria species infectious to chickens.

Macrophage migration inhibitory factor (MIF) was the first cytokine to be identified almost 40 years ago. Homologues of MIF have been isolated recently from invertebrates, making it an interesting molecule from an evolutionary as well as functional perspective. The present study represents the first report of MIF homologues in apicomplexan parasites, belonging to the genus Eimeria. A single full-length clone was isolated from Eimeria acervulina that shared between 35 and 38% amino acid identity with MIFs of vertebrates. A MIF cDNA from Eimeria tenella shared 64% amino acid identity with E. acervulina MIF. The mRNA expression was highest in merozoites, whereas developing oocysts and sporozoites expressed low to undetectable levels. Protein expression patterns were nearly identical to that observed by reverse transcriptase polymerase chain reaction (RT-PCR), suggesting strong developmental regulation. Immunofluorescence staining and co-localisation studies of E. acervulina merozoites indicated that MIF is distributed throughout the cytosol, and appears to be concentrated in the apical end of the parasite. The presence of MIF was detected in excretory/secretory (ES) products collected from E. acervulina merozoites, and isoelectric focusing indicated that three MIF isoforms are present in this stage. Phylogenetic analysis revealed that apicomplexan MIF sequences form a sister relationship to MIF-like molecules from Arabidopsis thaliana.

Amino Acid Sequence↗

Blockade of macrophage migration inhibitory factor ameliorates experimental autoimmune myocarditis.

Macrophage migration inhibitory factor (MIF) is a cytokine that plays a critical role in the regulation of macrophage effector functions and T-cell activation. However, its role in the pathogenesis of experimental autoimmune myocarditis (EAM) has remained unresolved. In this study, we studied the role of the MIF in EAM. We investigated the expression of MIF in EAM using enzyme-linked immunosorbent assay, Northern blotting, and immunohistochemistry. Moreover, a neutralizing antibody (Ab) to MIF was injected intraperitoneally from day 0 to 20 (experiment 1), or from day 13 to 19 (experiment 2), after the immunization. Disease severity was estimated by the macroscopic and microscopic findings for the heart, heart weight to body weight ratio, and cellular and humoral immune responses on day 21. Enhanced MIF protein and mRNA expression in the heart tissue and an elevated serum MIF concentration were confirmed in EAM. In experiment 1, the anti-MIF Ab treatment markedly inhibited the onset of EAM. Moreover, a significant reduction in disease severity was also achieved even after the delayed anti-MIF Ab treatment in experiment 2. Furthermore, we demonstrated that MIF blockade decreased the expression of VCAM-1, TNF-alpha, and IL-1beta and the migration of T-cells and macrophages in the EAM heart. These results demonstrate an important role of MIF in the pathogenesis of EAM and suggest that MIF blockade may be a promising new strategy for the treatment of myocarditis.

Animals↗

Regulation of macrophage migration inhibitory factor expression by glucocorticoids in vivo.

Glucocorticoid hormones are important anti-inflammatory agents because of their anti-inflammatory and proapoptotic action within the immune system. Their clinical usefulness remains limited however by side effects that result in part from their growth inhibitory action on sensitive target tissues. The protein mediator, macrophage migration inhibitory factor (MIF), is an important regulator of the host immune response and exhibits both glucocorticoid-antagonistic and growth-regulatory properties. MIF has been shown to contribute significantly to the development of immunopathology in several models of inflammatory disease. Although there is emerging evidence for a functional interaction between MIF and glucocorticoids in vitro, little is known about their reciprocal influence in vivo. We investigated the expression of MIF in rat tissues after ablation of the hypothalamic-pituitary-adrenal axis and after high-dose glucocorticoid administration. MIF expression is constitutive and independent of the influence of adrenal hormones. Hypophysectomy and the attendent loss of pituitary hormones, by contrast, decreased MIF protein content in the adrenal gland. Administration of dexamethasone was found to increase MIF protein expression in those organs that are considered to be sensitive to the growth inhibitory effects of glucocorticoids (immune and endocrine tissues, skin, and muscle). This increase was most likely because of a posttranscriptional regulatory effect because tissue MIF mRNA levels were not influenced by dexamethasone treatment. Finally, MIF immunoneutralization enhanced lymphocyte egress from blood during stress-induced lymphocyte redistribution, consistent with a functional interaction between MIF and glucocorticoids on immune cell trafficking in vivo. These findings suggest a role for MIF in both the homeostatic and physiological action of glucocorticoids in vivo.

Adrenal Glands↗

Macrophage migration inhibitory factor and development of type-1 diabetes in non-obese diabetic mice.

AIMS/HYPOTHESIS: T-cell activation by specific antigen has been found to increase macrophage migration inhibitory factor (MIF) expression, indicating its role as an important feature of T-cell activation in vitro and in vivo. To date, the potential role of MIF in the development of autoimmune-mediated diabetes mellitus has not been studied. METHODS: MIF-mRNA expression in splenic lymphocytes of spontaneously diabetic non-obese diabetic (NOD) mice (n=6), cyclophosphamide-treated NOD mice (n=6), 14-day-old non-diabetic NOD mice (n=7) and C57/Bl6 control mice (n=6) was monitored using an internally standardised competitive reverse transcription-polymerase chain reaction, and the MIF-protein levels were determined using Western blot analysis. In addition, the impact of intraperitoneally administered recombinant MIF-protein treatment on diabetes incidence in NOD mice was evaluated. RESULTS: MIF-mRNA expression was markedly increased in splenic lymphocytes of spontaneously diabetic NOD mice as well as in 8-week-old NOD mice treated with cyclophosphamide compared with 2-week-old non-diabetic NOD and healthy C57BL/6 control mice. Western blot analyses showed decreased lymphocytic MIF-protein content in diabetic as well as in cyclophosphamide-treated animals compared with 2-week-old non-diabetic NOD and healthy C57BL/6 mice, probably as a consequence of increased protein secretion. Furthermore, treatment of NOD mice with recombinant MIF-protein at 25 microg twice a week, from age 6 to 11 weeks, led to an increased diabetes incidence (86%; n=7) compared with untreated control groups (55%; n=20) at week 34. CONCLUSIONS/INTERPRETATION: In this study, we report for the first time that MIF-mRNA expression in splenic lymphocytes is up-regulated during development of cell-mediated diabetes in non-NOD mice. The data of our preliminary study suggest a possible role of MIF in autoimmune-inflammatory events, such as type-1 diabetes and also that anti-MIF therapeutic strategy might serve to attenuate autoimmune processes.

Age of Onset↗

Biochemical and mutational investigations of the enzymatic activity of macrophage migration inhibitory factor.

The protein mediator MIF has been identified as being released from immune cells by glucocorticoid stimulation and to counter-regulate glucocorticoid action. MIF also has been described recently to exhibit dopachrome tautomerase activity and to be structurally homologous to the bacterial enzymes 4-oxalocrotonate tautomerase (4-OT) and 5-carboxymethyl-2-hydroxymuconate isomerase (CHMI). We performed site-directed mutagenesis and biochemical analyses of mouse MIF in order to identify amino acid residues and protein domains that are essential for enzymatic reactivity. Mutant proteins which lacked a free N-terminal proline residue were enzymatically inactive, as was a preparation of native MIF modified covalently at its N terminus by 3-bromopyruvate, suggesting that this proline has a catalytic function. Substitutions of the internal histidine residues 42 and 63 did not affect enzymatic activity, indicating that these basic residues are not involved in dopachrome tautomerization. Carboxy-truncated forms of MIF (residues 1-110 and 1-104) also were inactive, affirming the role of the carboxy terminus in stable trimer formation and the importance of the trimer for enzymatic activity. Additional evidence for the homotrimeric structure of MIF under native solution conditions was obtained by SDS-PAGE analysis of MIF after chemical cross-linking at low protein concentrations. The enzymatic activity of MIF was found to be reversibly inhibited by micromolar concentrations of fatty acids with chain lengths of at least 16 carbon atoms. Of note, molecular modeling of the substrate L-dopachrome methyl ester into the active site of MIF suggests an acid-catalyzed enzymatic mechanism that is different from that deduced from studies of the enzymes 4-OT and CHMI. Finally, in vitro analysis of an enzymatically inactive MIF species (P2 --> S) indicates that the glucocorticoid counter-regulatory activity of MIF can be functionally dissociated from its tautomerization activity.

Amino Acid Sequence↗

Up-regulation of macrophage migration inhibitory factor in acute renal allograft rejection in the rat.

Recent studies have identified a key role for macrophage migration inhibitory factor (MIF) in a number of immune cell-mediated diseases. The current study investigated the potential role of MIF in acute allograft rejection. Lewis rats underwent bilateral nephrectomy and then received an orthotopic DA renal allograft or an orthotopic Lewis renal isograft. Groups of six animals were killed at day 1 or 5 after transplantation. No immunosuppression was used. Animals receiving a renal allograft exhibited severe rejection on day 5, as shown by high levels of serum creatinine, very low rates of creatinine clearance, and severe tubulitis with a dense macrophage and T cell infiltrate. In contrast, isografts had normal renal function on day 5 with no histological evidence of rejection. Northern blotting showed that renal MIF mRNA expression was unchanged at day 1, but was increased 3.5-fold on day 5. In situ hybridization showed a marked increase in MIF mRNA expression by tubular cells and MIF mRNA expression by many infiltrating mononuclear cells in day 5 allografts. Immunostaining confirmed an increase in tubular MIF protein expression, particularly in areas of severe tubular damage with prominent leucocytic infiltration. Double staining showed that many infiltrating macrophages and T cells expressed the MIF protein in day 5 allografts. There was only a minor increase in MIF expression in day 5 isografts, demonstrating that neither surgical injury nor stress cause significant up-regulation of MIF expression in allograft rejection. In conclusion, this study has demonstrated that local MIF production is specifically increased in acute renal allograft rejection. These results suggest that MIF may play an important role in the cellular immune response mediating acute allograft rejection.

Acute Disease↗

Macrophage migration inhibitory factor activates antigen-presenting dendritic cells and induces inflammatory cytokines in ulcerative colitis.

The level of macrophage migration inhibitory factor (MIF) and the functions of dendritic cells (DC) are up-regulated in the peripheral blood, and the numbers of MIF-expressing cells and mature DC are increased at the colonic mucosa from patients with ulcerative colitis (UC). However, a functional relationship between MIF and DC, and the role of MIF in the pathogenesis of UC, are not clear. In this study, we showed that a pure population of peripheral blood DC is a new and still unknown source of MIF. DC from UC patients produced significantly higher levels of MIF (17 x 5 +/- 9 x 8 ng/ml, n = 10) compared with patients with Crohns disease (CD) (4 x 6 +/- 2 x 5 ng/ml, n = 5, P< 0 x 01) and control subjects (5 x 0 +/- 2 x 6 ng/ml, n = 10, P< 0 x 01). A double immunofluorescence study revealed the expression of MIF by CD83-positive mature DC at the colonic mucosa from UC patients. Blood DC treated with high amounts of MIF (500 ng/ml) showed a significantly higher stimulatory capacity (43287 +/- 5998 CPM, n = 5) in an allogenic mixed leucocyte reaction compared with untreated DC (27528 +/- 8823 CPM, n = 5, P< 0 x 05). Study of intracellular cytokine expression showed that MIF induced significant levels of interleukin (IL)-1 and IL-8 in monocytes and DC from UC and CD patients. These results showing the capacity of MIF to induce increased functional capacity of DC, and to produce IL-1 and IL-8 from monocytes and DC, indicate a role of MIF in the induction and/or perpetuation of the inflammatory environment in UC.

Cells, Cultured↗

Macrophage migration inhibitory factor in the sera and at the colonic mucosa in patients with ulcerative colitis: clinical implications and pathogenic significance.

BACKGROUND: Inflammatory cytokines produced by activated macrophages are implicated in the pathogenesis of ulcerative colitis (UC). With the theory that macrophage migration inhibitory factor (MIF) may have a role in the accumulation of macrophages, we studied MIF in UC. MATERIALS AND METHODS: A total of 27 patients with UC, 14 patients with Crohn's diseases (CD), 11 patients with other forms of colitis and 26 normal controls were enrolled in the study. The levels of MIF in the sera and culture supernatant were measured by an enzyme-linked immunosorbent assay. MIF, macrophages and T cells were localized at the colonic mucosa by immunohistochemistry. RESULTS: The levels of MIF in the sera were significantly higher in UC than in normal controls (P < 0.05), in serum C-reactive protein (CRP) -positive cases with UC than in CRP-negative cases with UC (P < 0.05), and in patients with severe colitis with UC than in mild colitis with UC (P < 0.05). There was a positive relationship between serum MIF levels with the CRP levels and activities of colitis. However, the levels of MIF in patients with CD and other forms of colitis were not significantly different from their levels in normal controls and UC. Infiltrating cells at the colonic mucosa in UC and CD expressed MIF. CONCLUSIONS: These data suggest a role of MIF in the pathogenesis of UC. MIF may be used as a marker of disease activity in UC and control of MIF production may have therapeutic implications.

Adult↗

Macrophage migration inhibitory factor is a critical mediator of severe acute pancreatitis.

BACKGROUND & AIMS: Macrophage migration inhibitory factor (MIF), originally described as an inhibitor of the random migration of macrophages, has been shown recently to be involved in the pathogenesis of several inflammatory diseases such as sepsis. The aim of this study was to clarify the role of MIF in acute pancreatitis (AP). METHODS: Hemorrhagic necrotizing pancreatitis and edematous pancreatitis were induced by the injection of taurocholic acid (TCA pancreatitis) and cerulein (cerulein pancreatitis), respectively, on male Wistar rats. MIF levels in ascitic fluids, serum, and the organs were determined. The effects of anti-MIF antibody were examined on the prognosis of rats with TCA pancreatitis and of female CD-1 mice with choline-deficient, ethionine-supplemented, diet-induced model of severe AP. In addition, serum MIF levels in AP patients and in healthy controls were measured. RESULTS: Serum and ascitic MIF levels in TCA pancreatitis were increased rapidly and decreased gradually thereafter. Ascitic MIF levels were also increased in cerulein pancreatitis, but to a lesser degree. MIF level was increased in the lung in TCA pancreatitis, but not in the pancreas and the liver. Prophylactic (1 hour before and immediately after induction) administration of anti-MIF antibody significantly improved the survival rate of rats with TCA pancreatitis. The survival rate of mice with severe AP was also improved significantly by the antibody treatment. Serum MIF levels were higher in severe AP patients than mild AP patients and healthy controls. CONCLUSIONS: These results suggest a role of MIF in the pathogenesis of severe AP.

Acute Disease↗

Macrophage migration inhibitory factor is associated with aneurysmal expansion.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine released mainly from macrophages and activated lymphocytes. Both atherosclerosis and abdominal aortic aneurysm (AAA) are inflammatory diseases tightly linked to the function of these cells. The correlation and contribution of MIF to these human diseases remain unknown, although a recent rabbit study showed expression of this cytokine in atherosclerotic lesions. MATERIAL AND METHODS: MIF immunohistochemistry was performed on tissue sections from five normal aortas, seven atherosclerotic carotids, and six AAAs. A group of 112 men with small AAAs (defined as 3 to 5 cm) was recruited at the time of diagnosis, had serum samples taken, and was followed annually for 1 to 5 years (mean, 2.9 years) and referred for surgery if the AAA exceeded 5 cm in diameter. Of this study group, 98 had serum MIF measured with an enzyme-linked immunosorbent assay and 61 had detectable levels. RESULTS: In human atherosclerotic and aneurysmal lesions, MIF protein colocalized in macrophages, endothelial cells, and smooth muscle cells, but normal arteries had negligible MIF expression. Furthermore, serum-MIF levels correlated significantly with annual expansion rate (r = 0.28; P =.005), persisting after adjustment for initial AAA size, smoking habits, diastolic blood pressure, ankle blood pressure index, and age. After exclusion of 38 cases with MIF levels below the detection limit, initial AAA size was also significantly correlated with the MIF levels (r = 0.42; P =.001), persisting after adjustment for similar confounders, and the correlation coefficient with expansion rate increased to 0.42 (P =.001). CONCLUSION: Highly expressed MIF in macrophages, endothelial cells, and smooth muscle cells in lesions from atherosclerosis and AAA and significant association between serum MIF level and AAA initial size and AAA expansion rate in a group of patients with AAA suggest a potential involvement of this proinflammatory cytokine in the pathogenesis of these cardiovascular diseases.

Aged↗