Macrophage migration inhibitory factor (MIF) and risk for coronary heart disease: results from the MONICA/KORA Augsburg case-cohort study, 1984-2002

Impact of the MIF -173G/C variant on cardiovascular disease risk: a meta-analysis of 9,047 participants

Introduction

Many factors contribute to the risk of cardiovascular disease (CVD), an umbrella term for several different heart diseases, including inflammation. Macrophage migration inhibitory factor (MIF) is an important immune modulator that has been shown to be involved in the pathogenesis of different heart diseases, so understanding pathogenic variants of the MIF gene is important for risk stratification. We therefore conducted a meta-analysis to investigate whether the MIF -173G/C (rs755622) polymorphism is associated with CVD.

Methods

The PubMed, Science Direct, and Embase databases were searched from inception to June 2023 for case-control studies of the MIF -173G/C polymorphism and its relationship to any type of CVD. Correlations between the MIF -173G/C polymorphism and CVD were estimated by pooling the odds ratios (ORs) with 95% confidence intervals in allelic, dominant, and recessive models using random-effects meta-analysis.

Results

A total of 9,047 participants (4141 CVD cases and 4906 healthy controls) from 11 relevant studies were included. In the total population, there was no significant association between the MIF -173G/C (rs755622) polymorphism and the risk of developing CVD in the three different models. In a stratified analysis by ethnicity, the allelic model (C vs G) was significantly associated with CVD in the Arab and Asian populations (OR = 0.56, CI 0.42 -0.75 and OR = 1.28, CI 1.12 -1.46, respectively); the dominant model (CC+CG vs GG) was significantly associated with CVD in the Arab population (OR = 0.42, CI 0.30 -0.61); while the recessive model (GG+GC vs CC) was associated with CVD susceptibility in the Arab population (OR = 3.84, CI 1.57 -9.41). There were no significant associations between the MIF -173 G/C polymorphism and CVD risk in the European population. Conclusion, the MIF -173G/C polymorphism is associated with CVD in some populations.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, PROSPERO (CRD42023441139).

Genetic Variation of Migration Inhibitory Factor Gene rs2070766 Is Associated With Acute Coronary Syndromes in Chinese Population

Genetic variation of macrophage migration inhibitory factor (MIF) gene has been linked to coronary artery disease. We investigated an association between the polymorphism of MIF gene rs2070766 and acute coronary syndromes (ACS) and the predictive value of MIF gene variation in clinical outcomes. This study involved in 963 ACS patients and 932 control subjects from a Chinese population. All participants were genotyped for the single nucleotide polymorphism (SNP) of MIF gene rs2070766 using SNPscan™. A nomogram model using MIF genetic variation and clinical variables was established to predict risk of ACS. Major adverse cardiovascular events (MACE) were monitored during a follow-up period. The frequency of rs2070766 GG genotype was higher in ACS patients than in control subjects (6.2 vs 3.8%, p = 0.034). Multivariate logistic regression analysis revealed that individuals with mutant GG genotype had a 1.7-fold higher risk of ACS compared with individuals with CC or CG genotypes. Using MIF rs2070766 genotypes and clinical factors, we developed a nomogram model to predict risk of ACS. The nomogram model had a good discrimination with an area under the curve of 0.781 (95% CI: 0.759-0.804), concordance index of 0.784 (95% CI: 0.762-0.806) and well-fitted calibration. During the follow-up period of 25 months, Kaplan-Meier curves demonstrated that ACS patients carrying GG phenotype developed more MACE compared to CC or CG carriers (p < 0.05). GG genotype of MIF gene rs2070766 was associated with a higher risk of ACS in a Chinese population. The GG genotype carriers in ACS patients had worse clinical outcomes compared with those carrying CC or CG genotype. Together with rs2070766 genetic variant of MIF gene, we established a novel nomogram model that can provide individualized prediction for ACS.

Association between MIF gene promoter rs755622 and susceptibility to coronary artery disease and inflammatory cytokines in the Chinese Han population

Macrophage migration inhibitory factor (MIF) is an essential mediator of atherosclerotic plaque progression and instability leading to intracoronary thrombosis, therefore contributing to coronary artery disease (CAD). In this study, we investigated the relationship between MIF gene polymorphism and CAD in Chinese Han population. Three single nucleotide polymorphisms (SNP, rs755622, rs1007888 and rs2096525) of MIF gene were genotyped by TaqMan genotyping assay in 1120 control participants and 1176 CAD patients. Coronary angiography was performed in all CAD patients and Gensini score was used to assess the severity of coronary artery lesions. The plasma levels of MIF and other inflammatory mediators were measured by ELISA. The CAD patients had a higher frequency of CC genotype and C allele of rs755622 compared with that in control subjects (CC genotype: 6.5% vs. 3.9%, P = 0.008, C allele: 24.0% vs. 20.6%, P = 0.005). The rs755622 CC genotype was associated with an increased risk of CAD (OR: 1.804, 95%CI: 1.221-2.664, P = 0.003). CAD patients with a variation of rs755622 CC genotype had significantly higher Gensini score compared with patients with GG or CG genotype (all P < 0.05). In addition, the circulating MIF level was highest in CAD patients carrying rs755622 CC genotype (40.7 ± 4.2 ng/mL) and then followed by GC (37.9 ± 3.4 ng/mL) or GG genotype (36.9 ± 3.7 ng/mL, all P < 0.01). Our study showed an essential relationship between the MIF gene rs755622 variation and CAD in Chinese Han population. Individuals who carrying MIF gene rs755622 CC genotype were more susceptible to CAD and had more severe coronary artery lesion. This variation also had a potential influence in circulating MIF levels.

The Macrophage Migration Inhibitory Factor (MIF) Promoter Polymorphisms (rs3063368, rs755622) Predict Acute Kidney Injury and Death after Cardiac Surgery

Background: Macrophage Migration Inhibitory Factor (MIF) is highly elevated after cardiac surgery and impacts the postoperative inflammation. The aim of this study was to analyze whether the polymorphisms CATT_5–7 (rs5844572/rs3063368,“-794”) and G>C single-nucleotide polymorphism (rs755622,-173) in the MIF gene promoter are related to postoperative outcome. Methods: In 1116 patients undergoing cardiac surgery, the MIF gene polymorphisms were analyzed and serum MIF was measured by ELISA in 100 patients. Results: Patients with at least one extended repeat allele (CATT₇) had a significantly higher risk of acute kidney injury (AKI) compared to others (23% vs. 13%; OR 2.01 (1.40–2.88), p = 0.0001). Carriers of CATT₇ were also at higher risk of death (1.8% vs. 0.4%; OR 5.12 (0.99–33.14), p = 0.026). The GC genotype was associated with AKI (20% vs. GG/CC:13%, OR 1.71 (1.20–2.43), p = 0.003). Multivariate analyses identified CATT₇ predictive for AKI (OR 2.13 (1.46–3.09), p < 0.001) and death (OR 5.58 (1.29–24.04), p = 0.021). CATT₇ was associated with higher serum MIF before surgery (79.2 vs. 50.4 ng/mL, p = 0.008). Conclusion: The CATT₇ allele associates with a higher risk of AKI and death after cardiac surgery, which might be related to chronically elevated serum MIF. Polymorphisms in the MIF gene may constitute a predisposition for postoperative complications and the assessment may improve risk stratification and therapeutic guidance.

Functional variants in the promoter region of macrophage migration inhibitory factor rs755622 gene (MIF G173C) among patients with heart failure: Association with echocardiographic indices and disease severity

BACKGROUND

Heart failure (HF) is a serious public health concern resulting in death. An individual predisposition to HF is determined by relationship between genetic and environmental variables. The macrophage migration inhibitory factor (MIF) is a significant mediator that involved in a variety of inflammatory and cardiovascular diseases. To reveal contribution of MIF rs755622 G173C gene variants in the promoter region towards HF pathogenesis and investigate association between recognized genotype and clinical characteristics.

PATIENTS AND METHODS

We recruited 90 patients with HF, 63 with preserved ejection fraction (HFpEF) and 27 with reduced ejection fraction (HFrEF), and 60 age- and sex- matched controls. MIF rs755622 (G>C) single-nucleotide polymorphism was genotyped by PCR-RFLP method.

RESULTS

The GG genotype of MIF rs755622 gene polymorphism was more frequent in HF patients than in controls which increased the risk of HF by about 4.25 times (p<0.05). The distribution of the GG, GC and CC genotypes of MIF were 42%, 21% and 0.0% among HFrEF, and 33.3%, 55.6% and 11.1% among HFpEF respectively. Higher frequency of MIF rs755622 G allele among HFrEF (100%) compared to HFpEF (88.9%) (p = 0.007). MIF-GG genotype variant had significantly lower LVEF. In multivariate analysis, MIF-GG genotype was independent risk predictor among HF (OR 4.6).

CONCLUSION

MIF rs755622 (GG) could be considered as a probable genotypic risk factor for HF, especially in those with HFrEF which increases the possibility that MIF contribute to HF progression. MIF genotype assay may serve as early predictor and help to recognize those at great risk of developing HF.

MIF -173G/C (rs755622) polymorphism modulates coronary artery disease risk: evidence from a systematic meta-analysis

BACKGROUND

Coronary artery disease (CAD) remains one of the major causes of death in humans. Genetic testing may allow early detection and prevention of this disease. This study aimed to investigate the association between the macrophage migration inhibitory factor (MIF) -173G/C (rs755622) polymorphism and susceptibility to CAD based on a meta-analysis.

METHODS

We searched several databases to identify observational case-control studies investigating the association between the MIF -173G > C (rs755622) polymorphism and CAD risk published before July 30, 2019. Data were analyzed using the STATA software.

RESULTS

Six studies, comprising a total of 1172 CAD cases and 1564 controls evaluated for MIF polymorphisms, were included. The occurrence of CAD was found to be associated with the C allele of the MIF rs755622 SNP in the total population (C/G, OR = 1.489, 95% CI = 1.223-1.813). Further, MIF -173G/C polymorphism was significantly associated with CAD under the allelic model in the Asian (C/G, OR = 1.775, 95% CI = 1.365-2.309) and Caucasian (C/G, OR = 1.288, 95% CI 1.003-1.654) subgroups. The data showed that the risk of CAD was higher in the population carrying the C allele.

CONCLUSIONS

We found evidence of associations between MIF -173C/G and CAD susceptibility in the Asian and Caucasian populations.

MIF gene rs755622 polymorphism positively associated with acute coronary syndrome in Chinese Han population: case-control study

Macrophage migration inhibitory factor (MIF) has been recognized as a major player in the pathogenesis of atherosclerosis. This study determined the association between polymorphisms of MIF gene and acute coronary syndrome (ACS). The polymorphism of MIF gene (rs755622, rs1007888 and rs2096525) was analyzed in 1153 healthy controls and 699 ACS cases in Chinese Han population. Plasma MIF level was also measured in part of ACS patients (139/19.9%) and healthy controls (129/11.2%) randomly. Most participants including healthy controls and ACS patients carried rs755622 GG (63.1% vs. 56.7%) and CG genotypes (33.1% vs. 38.9%) and G allele of rs755622 (79.6% vs. 76.1%, respectively), while CC genotype (3.8% vs. 4.4%) and C allele (20.4% vs. 23.9%) carriers were the lowest. Multivariate logistic regression analysis showed that carriers with rs755622 C allele had a higher risk of ACS compared to other genotypes (AOR = 1.278, 95% CI: 1.042-1.567). In addition, CC genotype carriers had the highest plasma levels of MIF than other genotype carriers. The MIF level in ACS patients with CC genotype was significantly higher than ACS patients carrying GG genotype and healthy controls carrying 3 different genotypes of MIF gene rs755622. Our findings indicate that MIF gene rs755622 variant C allele is associated with increased risk of ACS. Identification of this MIF gene polymorphism may help for predicting the risk of ACS.

Circulating MIF Levels Predict Clinical Outcomes in Patients With ST-Elevation Myocardial Infarction After Percutaneous Coronary Intervention

BACKGROUND

The purpose of the study was to assess the value of admission macrophage migration inhibitory factor (MIF) levels in predicting clinical outcomes in ST-elevation myocardial infarction (STEMI) patients.

METHODS

For this study we recruited 498 STEMI patients after they received percutaneous coronary intervention (PCI), 40 with stable angina pectoris and 137 healthy participants. Plasma MIF levels were measured at admission and after PCI. The primary end points were in-hospital mortality and major adverse cardio-and/or cerebrovascular events (MACCE) during hospitalization and 3.2-year follow-up period.

RESULTS

Admission MIF levels were elevated in 88.4% of STEMI patients over the upper reference limit of healthy controls and it was 3- to 7-fold higher than that in stable angina pectoris and control groups (122 ± 61 vs 39 ± 19 vs 17 ± 8 ng/mL; P < 0.001). Admission MIF levels were significantly higher in patients who died after myocardial infarction vs survivors. For predicting in-hospital mortality using the optimal cutoff value (127.8 ng/mL) of MIF, the area under the receiver operating characteristic curve for MIF was 0.820, similar area under the receiver operating characteristic curve values for predicting short-term outcomes were observed for high-sensitivity troponin T, CK-MB, N-terminal probrain natriuretic peptide, and Global Registry of Acute Coronary Events (GRACE) score. Although peak high-sensitivity troponin T and N-terminal probrain natriuretic peptide also predicted MACCE during the follow-up period, only higher admission MIF levels predicted in-hospital mortality and MACCE during the 3.2-year follow-up. Multivariate regression analysis showed the independent predictive value of a higher admission MIF level (≥ 127.8 ng/mL) on in-hospital mortality (odds ratio, 9.1; 95% confidence interval, 1.7-47.2) and 3.2-year MACCE (hazard ratio, 2.8; 95% confidence interval, 1.5-5.6).

CONCLUSIONS

A higher admission MIF level is an independent predictor for in-hospital mortality and long-term MACCE in STEMI patients who underwent PCI.

Elevated plasma macrophage migration inhibitor factor as a risk factor for the development of post-stroke depression in ischemic stroke

BACKGROUND

Macrophage migration inhibitory factor (MIF), a central cytokine of the innate immunity and inflammatory responses, has been reported to link to the pathophysiology of cardiovascular disease and depression. The aim of this study was to test the possible association between plasma MIF and the development of post-stroke depression (PSD) in Chinese patients with acute ischemic stroke (AIS).

METHODS

The first-ever AIS patients who were hospitalized at Affiliated Hospital of Weifang Medical College during the period from November 2015 to September 2017 were included. Neurological and neuropsychological evaluations were conducted at the 3-month follow-up. Plasma concentrations of MIF were tested by Quantikine Human MIF Immunoassay. Plasma levels of homocysteine (HCY), C-reactive protein (CRP) and Interleukin 6 (IL-6) were also tested. Results were expressed as percentages for categorical variables and as medians (Interquartile range-IQR) for the continuous variables.

RESULTS

Finally, 333 stroke patients were included, and 95 out of those patients (28.5%) were classified as major depression. In the patients with major depression, plasma levels of MIF were higher compared with those in patients free-depression [27.3(IQR, 23.5-34.9) ng/ml vs. 20.9(IQR, 17.0-24.8) ng/ml; Z = 8.369, P < 0.001]. For each 1unit increase of MIF, the unadjusted and adjusted risk of PSD increased by 18% (odds ratios [OR]: 1.18; 95% confidence interval [CI], 1.13-1.23, P < 0.001) and 11% (1.11; 1.02-1.16, P = 0.001), respectively. In a multivariate model using the elevated levels of MIF (≥median) vs. normal (<median) together with the other significant clinical variables, the marker displayed prognostic information (PSD: OR for fourth quartile, 3.05 [95% CI, 1.65-6.11; P < 0.001]). When MIF was added to the model containing established significant risk factors, Area Under the Receiver Operating Characteristic curve (AUROC; standard error) was increased from 0.81(0.025) to 0.86(0.019). A significant difference in the AUROC between the established risk factors alone and the addition of MIF was observed (difference, 0.05[0.006]; P = 0.004).

CONCLUSION

The present study demonstrated that elevated plasma levels of MIF at admission were associated with increased risk of PSD in the next three months and might be useful in identifying stroke at risk for PSD for early prevention strategies.

The influence of low-grade inflammation on platelets in patients with stable coronary artery disease

Inflammation is likely to be involved in all stages of atherosclerosis. Numerous inflammatory biomarkers are currently being studied, and even subtle increases in inflammatory biomarkers have been associated with increased risk of cardiovascular events in patients with coronary artery disease (CAD). Low-grade inflammation may influence both platelet production and platelet activation potentially leading to enhanced platelet aggregation. Thrombopoietin is considered the primary regulator of platelet production, but it likely acts in conjunction with numerous cytokines, of which many have altered levels in CAD. Previous studies have shown that high-sensitive C-reactive protein (CRP) independently predicts increased platelet aggregation in stable CAD patients. Increased levels of CRP, fibrinogen, interleukin-6, stromal cell-derived factor-1, CXC motif ligand 16, macrophage migration inhibitory factor, RANTES, calprotectin, and copeptin have been associated with increased risk of cardiovascular events in CAD patients. Additionally, some of these inflammatory markers have been associated with enhanced platelet activation and aggregation. However, CRP and other inflammatory markers provide only limited additional predictive value to classical risk factors such as smoking, blood pressure, and cholesterol levels. Existing data do not clarify whether inflammation simply accompanies CAD and increased production and aggregation of platelets, or whether a causal relationship exists. In this review, we provide a comprehensive overview of inflammatory markers in stable CAD with particular emphasis on platelet production, activation, and aggregation in CAD patients.

Macrophage Migration Inhibitory Factor Predicts Outcome in Complex Aortic Surgery

The perioperative inflammatory response is associated with outcome after complex aortic repair. Macrophage migration inhibitory factor (MIF) shows protective effects in ischemia-reperfusion (IR), but also adverse pro-inflammatory effects in acute inflammation, potentially leading to adverse outcome, which should be investigated in this trial. This prospective study enrolled 52 patients, of whom 29 (55.7%) underwent open repair (OR) and 23 (44.3%) underwent endovascular repair (ER) between 2014 and 2015. MIF serum levels were measured until 72 h post-operatively. We used linear mixed models and ROC analysis to analyze the MIF time-course and its diagnostic ability. Compared to ER, OR induced higher MIF release perioperatively; at 12 h after ICU admission, MIF levels were similar between groups. MIF course was significantly influenced by baseline MIF level (P = 0.0016) and acute physiology and chronic health evaluation (APACHE) II score (P = 0.0005). MIF level at 24 h after ICU admission showed good diagnostic value regarding patient survival [sensitivity, 80.0% (28.4–99.5%); specificity, 51.2% (35.1–67.1%); AUC, 0.688 (0.534–0.816)] and discharge modality [sensitivity, 87.5% (47.3–99.7%); specificity, 73.7% (56.9–86.6%), AUC, 0.789 (0.644–0.896)]. Increased perioperative MIF-levels are related to an increased risk of adverse outcome in complex aortic surgery and may represent a biomarker for risk stratification in complex aortic surgery.

Lower circulating migration inhibitory factor protein is associated with metabolic syndrome and diabetes

Aim: The controversial relationship between macrophage migration inhibitory factor (MIF) and the likelihood of cardiometabolic diseases was investigated. Results/methodology: Assayed MIF protein from 1225 adults was cross-sectionally analyzed. MIF was independently inversely associated with age, total testosterone and positively with high-density lipoprotein-cholesterol. In men MIF correlation with age, testosterone and waist circumference converted from inverse in the upper to positive in the bottom MIF third. Both metabolic syndrome and diabetes were significantly associated, in combined gender, with the intermediate (vs the highest) MIF tertile at an odds ratio 1.6. Coronary heart disease was not significantly related with MIF in either gender. Discussion/conclusion: Findings are consistent with oxidative damage to MIF protein and its involvement in autoimmune activation, likely more extensive in women.

MIF family cytokines in cardiovascular diseases and prospects for precision-based therapeutics

INTRODUCTION

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with chemokine-like functions that increasingly is being studied in different aspects of cardiovascular disease. MIF was first identified as a proinflammatory and pro-survival mediator within the immune system, and a second structurally related MIF family member, D-dopachrome tautomerase (a.k.a. MIF-2), was reported recently. Both MIF family members are released by myocardium and modulate the manifestations of cardiovascular disease, specifically in myocardial ischemia. Areas covered: A scientific overview is provided for the involvement of MIF family cytokines in the inflammatory pathogenesis of atherosclerosis, myocardial infarction, and ischemia-reperfusion injury. We summarize findings of experimental, human genetic and clinical studies, and suggest therapeutic opportunities for modulating the activity of MIF family proteins that potentially may be applied in a MIF allele specific manner. Expert opinion: Knowledge of MIF, MIF-2 and their receptor pathways are under active investigation in different types of cardiovascular diseases, and novel therapeutic opportunities are being identified. Clinical translation may be accelerated by accruing experience with MIF-directed therapies currently in human testing in cancer and autoimmunity.

MIF Gene Polymorphism rs755622 Is Associated With Coronary Artery Disease and Severity of Coronary Lesions in a Chinese Kazakh Population: A Case-Control Study

Inflammation plays an important role in the pathogenesis of atherosclerosis. Recent studies indicate that macrophage migration inhibitory factor (MIF) is a potent proinflammatory cytokine which mediates the inflammatory process during atherosclerosis. The polymorphism of MIF gene (rs755622 [-173G/C], rs1007888, and rs2096525) were genotyped by TaqMan single nucleotide polymorphism (SNP) genotyping assay in 320 patients with coronary artery disease (CAD) and 603 controls in a Chinese Kazakh population. Coronary angiography was performed on all CAD patients and Gensini score was used to assess the severity of coronary artery lesions. The frequency of the CC genotype and C allele of rs755622 were significantly higher in CAD patients than that in control subjects (8.4% vs. 5.1%, P < 0.001, 30.3% vs. 22.1%, P < 0.001, respectively). Multivariate logistic regression analysis showed that individuals with CC genotype or C allele had a higher risk for CAD (CC genotype vs. GG genotype, OR = 2.224, 95% CI, 1.239-3.992, P = 0.007, and C allele vs. G allele, OR = 1.473, 95% CI, 1.156-1.876, P = 0.002, respectively). Moreover, CAD patients with rs755622 C allele (CC + CG genotype) have higher levels of Gensini score when compared to C allele noncarriers (32.74 ± 26.66 vs. 21.44 ± 19.40, P < 0.001, adjusted). Our results suggested that the CC genotype and C allele of MIF rs755622 SNP may be a genetic marker for the risk of CAD and potentially predict the severity of CAD in Chinese Kazakh population.

Pathogenic roles of macrophage migration inhibitory factor during dengue virus infection

Dengue virus (DENV) infection is the most common cause of viral hemorrhagic fever, which can lead to life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Hemorrhage and plasma leakage are two major hallmarks of DHF/DSS. Because the mechanisms causing these pathogenic changes are unclear, there is no effective therapy against DHF/DSS. In this review, we focus on the possible pathogenic effects of a pleiotropic cytokine, macrophage migration inhibitory factor (MIF), on the pathogenesis of DENV infection. MIF is a critical mediator of the host immune response and inflammation, and there is a correlation between the serum levels of MIF and disease severity in dengue patients. Furthermore, MIF knock-out mice exhibit less severe clinical disease and lethality. However, the role of MIF in the pathogenesis of DHF/DSS is not limited to immune cell recruitment. Recent evidence indicates that DENV infection induced MIF production and may contribute to vascular hyperpermeability and viral replication during DENV infection. The expression of both adhesion and coagulation molecules on MIF-stimulated monocytes and endothelial cells is also increased, which may contribute to inflammatory and anticoagulatory states during DHF/DSS. Therefore, blocking MIF production or its function may provide a solution for the treatment and prevention of DHF/DSS.

Increased circulating macrophage migration inhibitory factor levels are associated with coronary artery disease

BACKGROUND

To evaluate the macrophage migration inhibitory factor and E-selectin levels in patients with acute coronary syndrome.

MATERIALS/METHODS

We examined the plasma migration inhibitory factor and E-selectin levels in 87 patients who presented with chest pain at our hospital. The patients were classified into two groups according to their cardiac status. Sixty-five patients had acute myocardial infarction, and 22 patients had non-cardiac chest pain (non-coronary disease). We designated the latter group of patients as the control group. The patients who presented with acute myocardial infarction were further divided into two subgroups: ST-elevated myocardial infarction (n = 30) and non-ST elevated myocardial infarction (n = 35).

RESULTS

We found higher plasma migration inhibitory factor levels in both acute myocardial infarction subgroups than in the control group. However, the E-selectin levels were similar between the acute myocardial infarction and control patients. In addition, we did not find a significant difference in the plasma migration inhibitory factor levels between the ST elevated myocardial infarction and NST-elevated myocardial infarction subgroups.

DISCUSSION

The circulating concentrations of migration inhibitory factor were significantly increased in acute myocardial infarction patients, whereas the soluble E-selectin levels were similar between acute myocardial infarction patients and control subjects. Our results suggest that migration inhibitory factor may play a role in the atherosclerotic process.

Macrophage migration inhibitory factor deficiency ameliorates high-fat diet induced insulin resistance in mice with reduced adipose inflammation and hepatic steatosis

Macrophage infiltration is a critical determinant of high-fat diet induced adipose tissue inflammation and insulin resistance. The precise mechanisms underpinning the initiation of macrophage recruitment and activation are unclear. Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine, displays chemokine-like properties. Circulating MIF levels are elevated during obesity however its role in high-fat diet induced adipose inflammation and insulin resistance remains elusive. Wildtype and MIF-/- C57Bl\6J mice were fed chow or high-fat diet. Body weight and food intake was assessed. Glucose homeostasis was monitored by glucose and insulin tolerance tests. Adipose tissue macrophage recruitment and adipose tissue insulin sensitivity was evaluated. Cytokine secretion from stromal vascular fraction, adipose explants and bone marrow macrophages was measured. Inflammatory signature and insulin sensitivity of 3T3-L1-adipocytes co-cultured with wildtype and MIF-/- macrophage was quantified. Hepatic triacylglyceride levels were assessed. MIF-/- exhibited reduced weight gain. Age and weight-matched obese MIF-/- mice exhibited improved glucose homeostasis coincident with reduced adipose tissue M1 macrophage infiltration. Obese MIF-/- stromal vascular fraction secreted less TNFα and greater IL-10 compared to wildtype. Activation of JNK was impaired in obese MIF-/-adipose, concomitant with pAKT expression. 3T3-L1-adipocytes cultured with MIF-/- macrophages had reduced pro-inflammatory cytokine secretion and improved insulin sensitivity, effects which were also attained with MIF inhibitor ISO-1. MIF-/- liver exhibited reduced hepatic triacyglyceride accumulation, enhanced pAKT expression and reduced NFκB activation. MIF deficiency partially protects from high-fat diet induced insulin resistance by attenuating macrophage infiltration, ameliorating adipose inflammation, which improved adipocyte insulin resistance ex vivo. MIF represents a potential therapeutic target for treatment of high-fat diet induced insulin resistance.

Impact of counterbalance between macrophage migration inhibitory factor and its inhibitor Gremlin-1 in patients with coronary artery disease

OBJECTIVE

Monocyte infiltration is a critical step in the pathophysiology of plaque instability in coronary artery disease (CAD). Macrophage migration inhibitory factor (MIF) is involved in atherosclerotic plaque progression and instability leading to intracoronary thrombosis. Gremlin-1 (Grem1) has been recently identified as endogenous inhibitor of MIF. To date there are no data on the clinical impact of this interaction in cardiovascular patients.

METHODS AND RESULTS

Plasma levels of MIF and Grem1 were determined by enzyme-linked immunoassay in patients with acute coronary syndromes (ACS, n = 120; stable CAD, n = 166 and healthy control subjects, n = 25). MIF levels were significantly increased in ACS compared to stable CAD and healthy control (ACS: median 2.85; IQR 3.52 ng/ml; versus SAP: median 1.22; IQR 2.99 ng/ml; versus healthy control: median 0.10; IQR 0.09 ng/ml, p < 0.001). Grem1 levels were significantly higher in ACS and stable CAD patients compared to healthy control (ACS: median 211.00; IQR 130.47 ng/ml; SAP: median 220.20; IQR 120.93 ng/ml, versus healthy control: median 90.57; IQR 97.68 ng/ml, p < 0.001). Grem1/MIF ratio was independently associated with ACS, whereas the single parameters were not associated with the presence of ACS. Furthermore, Grem1/MIF ratio was associated with angiographic signs of intracoronary thrombi and severity of thrombus burden.

CONCLUSION

These novel findings suggest a potential role of Grem1/MIF ratio to indicate acuity of CAD and the grade of plaque stability. Prospective angiographic cohort studies involving plaque imaging techniques are warranted to further characterize the prognostic role of this novel risk marker in CAD patients.

Macrophage migration inhibitory factor (MIF) knockout preserves cardiac homeostasis through alleviating Akt-mediated myocardial autophagy suppression in high-fat diet-induced obesity

Background

Macrophage migration inhibitory factor (MIF) plays a role in the development of obesity and diabetes. However, whether MIF plays a role in fat diet-induced obesity and associated cardiac anomalies still remains unknown. The aim of this study was to examine the impact of MIF knockout on high fat diet-induced obesity, obesity-associated cardiac anomalies and the underlying mechanisms involved with a focus on Akt-mediated autophagy.

Methods

Adult male wild-type (WT) and MIF knockout (MIF^−/−) mice were placed on 45% high fat diet for 5 months. Oxygen consumption, CO₂ production, respiratory exchange ratio (RER), locomotor activity, and heat generation were measured using energy calorimeter. Echocardiographic, cardiomyocyte mechanical and intracellular Ca²⁺ properties were assessed. Apoptosis was examined using TUNEL staining and western blot analysis. Akt signaling pathway and autophagy markers were evaluated. Cardiomyocytes isolated from WT and MIF^−/− mice were treated with recombinant mouse MIF (rmMIF).

Results

High fat diet feeding elicited increased body weight gain, insulin resistance, and caloric disturbance in WT and MIF^−/− mice. High fat diet induced unfavorable geometric, contractile and histological changes in the heart, the effects of which were alleviated by MIF knockout. In addition, fat diet-induced cardiac anomalies were associated with Akt activation and autophagy suppression, which were nullified by MIF deficiency. In cardiomyocytes from WT mice, autophagy was inhibited by exogenous rmMIF through Akt activation. In addition, MIF knockout rescued palmitic acid-induced suppression of cardiomyocyte autophagy, the effect of which was nullified by rmMIF.

Conclusions

These results indicate that MIF knockout preserved obesity-associated cardiac anomalies without affecting fat diet-induced obesity, probably through restoring myocardial autophagy in an Akt-dependent manner. Our findings provide new insights for the role of MIF in obesity and associated cardiac anomalies.

Oxidative stress-mediated (sex-specific) loss of protection against type-2 diabetes by macrophage migration inhibitory factor (MIF)-173G/C polymorphism

BACKGROUND

The archetypical yet atypical cytokine macrophage migration inhibitory factor (MIF) fulfills pleiotropic immune functions in inflammatory diseases. Evidence emerging from both expression and functional studies implicates MIF in various aspects of cardiovascular diseases. We aimed to determine the covariates of MIF-173G/C polymorphism and its influence on type-2 diabetes risk in a sample representative of middle-aged Turks.

METHODS

Randomly selected 2250 Turkish adults (mean age; 49.7±11.9, 48.5% male) were genotyped for -173G/C polymorphism using hybridization probes in Real-Time PCR LC480 device.

RESULTS

The MIF-173CC genotype prevailed in 3.7% in men and 2.9% in women. C-allele carriage was associated linearly with wider waist girth, independently of fasting glucose, and was further related to higher apolipoprotein B (apoB) (p<0.05) in men, but not women. Logistic regression analysis showed the C-allele carriage to tend to predict new-onset diabetes (RR 1.51; [95% CI 0.98; 2.32]), additively to age and fasting glucose in men, but not in women. In contrast, risk for established (baseline) diabetes mellitus was lower (OR=0.49, 95% Cl 0.26-0.93, p=0.03) in heterozygotes, after adjustment for atherogenic dyslipidemia and other confounders.

CONCLUSION

MIF-173GC polymorphism independently contributes to abdominal obesity and is related to apoB concentrations apparently in men alone. Tendency of the -173C-allele carriage to predict new-onset diabetes independently was also confined to men. These gender-modulated associations suggest novel gene-gender-environmental interactions originating from a proinflammatory state.

Role of MIF in myocardial ischaemia and infarction: insight from recent clinical and experimental findings

First discovered in 1966 as an inflammatory cytokine, MIF (macrophage migration inhibitory factor) has been extensively studied for its pivotal role in a variety of inflammatory diseases, including rheumatoid arthritis and atherosclerosis. Although initial studies over a decade ago reported increases in circulating MIF levels following acute MI (myocardial infarction), the dynamic changes in MIF and its pathophysiological significance following MI have been unknown until recently. In the present review, we summarize recent experimental and clinical studies examining the diverse functions of MIF across the spectrum of acute MI from brief ischaemia to post-infarct healing. Following an acute ischaemic insult, MIF is rapidly released from jeopardized cardiomyocytes, followed by a persistent MIF production and release from activated immune cells, resulting in a sustained increase in circulating levels of MIF. Recent studies have documented two distinct actions of MIF following acute MI. In the supra-acute phase of ischaemia, MIF mediates cardioprotection via several distinct mechanisms, including metabolic activation, apoptosis suppression and antioxidative stress. In prolonged myocardial ischaemia, however, MIF promotes inflammatory responses with largely detrimental effects on cardiac function and remodelling. The pro-inflammatory properties of MIF are complex and involve MIF derived from cardiac and immune cells contributing sequentially to the innate immune response evoked by MI. Emerging evidence on the role of MIF in myocardial ischaemia and infarction highlights a significant potential for the clinical use of MIF agonists or antagonists and as a unique cardiac biomarker.

Macrophage migration inhibitory factor deficiency augments doxorubicin-induced cardiomyopathy

Background

Recent evidence has depicted a role of macrophage migration inhibitory factor (MIF) in cardiac homeostasis under pathological conditions. This study was designed to evaluate the role of MIF in doxorubicin‐induced cardiomyopathy and the underlying mechanism involved with a focus on autophagy.

Methods and Results

Wild‐type (WT) and MIF knockout (MIF^−/−) mice were given saline or doxorubicin (20 mg/kg cumulative, i.p.). A cohort of WT and MIF^−/− mice was given rapamycin (6 mg/kg, i.p.) with or without bafilomycin A1 (BafA1, 3 μmol/kg per day, i.p.) for 1 week prior to doxorubicin challenge. To consolidate a role for MIF in the maintenance of cardiac homeostasis following doxorubicin challenge, recombinant mouse MIF (rmMIF) was given to MIF^−/− mice challenged with or without doxorubicin. Echocardiographic, cardiomyocyte function, and intracellular Ca²⁺ handling were evaluated. Autophagy and apoptosis were examined. Mitochondrial morphology and function were examined using transmission electron microscopy, JC‐1 staining, MitoSOX Red fluorescence, and mitochondrial respiration complex assay. DHE staining was used to evaluate reactive oxygen species (ROS) generation. MIF knockout exacerbated doxorubicin‐induced mortality and cardiomyopathy (compromised fractional shortening, cardiomyocyte and mitochondrial function, apoptosis, and ROS generation). These detrimental effects of doxorubicin were accompanied by defective autophagolysosome formation, the effect of which was exacerbated by MIF knockout. Rapamycin pretreatment rescued doxorubicin‐induced cardiomyopathy in WT and MIF^−/− mice. Blocking autophagolysosome formation using BafA1 negated the cardioprotective effect of rapamycin and rmMIF.

Conclusions

Our data suggest that MIF serves as an indispensable cardioprotective factor against doxorubicin‐induced cardiomyopathy with an underlying mechanism through facilitating autophagolysosome formation.

Inflammatory biomarkers for predicting cardiovascular disease

The pathology of cardiovascular disease (CVD) is complex; multiple biological pathways have been implicated, including, but not limited to, inflammation and oxidative stress. Biomarkers of inflammation and oxidative stress may serve to help identify patients at risk for CVD, to monitor the efficacy of treatments, and to develop new pharmacological tools. However, due to the complexities of CVD pathogenesis there is no single biomarker available to estimate absolute risk of future cardiovascular events. Furthermore, not all biomarkers are equal; the functions of many biomarkers overlap, some offer better prognostic information than others, and some are better suited to identify/predict the pathogenesis of particular cardiovascular events. The identification of the most appropriate set of biomarkers can provide a detailed picture of the specific nature of the cardiovascular event. The following review provides an overview of existing and emerging inflammatory biomarkers, pro-inflammatory cytokines, anti-inflammatory cytokines, chemokines, oxidative stress biomarkers, and antioxidant biomarkers. The functions of each biomarker are discussed, and prognostic data are provided where available.

Proinflammatory cytokines, adiponectin, and increased risk of primary cardiovascular events in diabetic patients with or without renal dysfunction: results from the ESTHER study

OBJECTIVE

Inflammatory processes contribute to both diabetes and cardiovascular risk. We wanted to investigate whether circulating concentrations of proinflammatory immune mediators and adiponectin in diabetic patients are associated with incident cardiovascular events.

RESEARCH DESIGN AND METHODS

In 1,038 participants with diabetes of the population-based ESTHER study, of whom 326 showed signs of renal dysfunction, Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for the association of increasing concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), IL-18, macrophage migration inhibitory factor (MIF), adiponectin, and leptin with cardiovascular events (myocardial infarction, stroke, or fatal cardiovascular event) during a follow-up period of 8 years.

RESULTS

During follow-up, 161 subjects with diabetes experienced a primary cardiovascular event. Proinflammatory markers were not associated with a higher risk for primary cardiovascular events in the total study population after adjustment for multiple confounders. However, IL-6 and MIF were associated with cardiovascular events in subjects with renal dysfunction (HR for the comparison of top vs. bottom tertile 1.98 [95% CI 1.12-3.52], P [trend] = 0.10 for IL-6; 1.48 [0.87-2.51], P [trend] = 0.04 for MIF). Adiponectin levels were associated with cardiovascular events in the total population (1.48 [1.01-2.21], P [trend] = 0.03), and the association was even more pronounced in the subgroup with renal dysfunction (1.97 [1.08-3.57], P [trend] = 0.02).

CONCLUSIONS

In particular, the absence of an association between CRP and a U-shaped association of adiponectin levels with incident cardiovascular events show that associations between circulating immune mediators and cardiovascular risk differ between diabetic patients and subjects of the general population.

Arrest Functions of the MIF Ligand/Receptor Axes in Atherogenesis

Macrophage migration inhibitory factor (MIF) has been defined as an important chemokine-like function (CLF) chemokine with an essential role in monocyte recruitment and arrest. Adhesion of monocytes to the vessel wall and their transendothelial migration are critical in atherogenesis and many other inflammatory diseases. Chemokines carefully control all steps of the monocyte recruitment process. Those chemokines specialized in controlling arrest are typically immobilized on the endothelial surface, mediating the arrest of rolling monocytes by chemokine receptor-triggered pathways. The chemokine receptor CXCR2 functions as an important arrest receptor on monocytes. An arrest function has been revealed for the bona fide CXCR2 ligands CXCL1 and CXCL8, but genetic studies also suggested that additional arrest chemokines are likely to be involved in atherogenic leukocyte recruitment. While CXCR2 is known to interact with numerous CXC chemokine ligands, the CLF chemokine MIF, which structurally does not belong to the CXC chemokine sub-family, was surprisingly identified as a non-cognate ligand of CXCR2, responsible for critical arrest functions during the atherogenic process. MIF was originally identified as macrophage migration inhibitory factor (this function being eponymous), but is now known as a potent inflammatory cytokine with CLFs including chemotaxis and leukocyte arrest. This review will cover the mechanisms underlying these functions, including MIF’s effects on LFA1 integrin activity and signal transduction, and will discuss the structural similarities between MIF and the bona fide CXCR2 ligand CXCL8 while emphasizing the structural differences. As MIF also interacts with CXCR4, a chemokine receptor implicated in CXCL12-elicited lymphocyte arrest, the arrest potential of the MIF/CXCR4 axis will also be scrutinized as well as the recently identified role of pericyte MIF in attracting leukocytes exiting through venules as part of the pericyte “motility instruction program.”

Macrophage migration inhibitory factor plays a permissive role in the maintenance of cardiac contractile function under starvation through regulation of autophagy

AIMS

The cytokine macrophage migration inhibitory factor (MIF) protects the heart through AMPK activation. Autophagy, a conserved pathway for bulk degradation of intracellular proteins and organelles, helps preserve and recycle energy and nutrients for cells to survive under starvation. This study was designed to examine the role of MIF in cardiac homeostasis and autophagy regulation following an acute starvation challenge.

METHODS AND RESULTS

Wild-type (WT) and MIF knockout mice were starved for 48 h. Echocardiographic data revealed little effect of starvation on cardiac geometry, contractile and intracellular Ca²⁺ properties. MIF deficiency unmasked an increase in left ventricular end-systolic diameter, a drop in fractional shortening associated with cardiomyocyte contractile and intracellular Ca²⁺ anomalies following starvation. Interestingly, the unfavourable effect of MIF deficiency was associated with interruption of starvation-induced autophagy. Furthermore, restoration of autophagy using rapamycin partially protected against starvation-induced cardiomyocyte contractile defects. In our in vitro model of starvation, neonatal mouse cardiomyocytes from WT and MIF-/- mice and H9C2 cells were treated with serum free-glucose free DMEM for 2 h. MIF depletion dramatically attenuated starvation-induced autophagic vacuole formation in neonatal mouse cardiomyocytes and exacerbated starvation-induced cell death in H9C2 cells.

CONCLUSION

In summary, these results indicate that MIF plays a permissive role in the maintenance of cardiac contractile function under starvation by regulation of autophagy.

Job strain-associated inflammatory burden and long-term risk of coronary events: findings from the MONICA/KORA Augsburg case-cohort study

BACKGROUND

We examined the association between job strain and coronary heart disease (CHD) and investigated the role of markers of inflammation and endothelial dysfunction as possible mediators of job strain-associated CHD risk.

METHODS

The sample (n = 1027) included employed participants (35-64 years old, 68% male) from the population-based MONICA/KORA (Monitoring of Trends and Determinants in Cardiovascular Disease/Kooperative Gesundheitsforschung in der Region Augsburg) studies. At baseline Karasek's Job Strain Index was assessed during standardized personal interviews, and nine biological markers were measured (1984-1995). Participants were followed (average, 12 years) to assess incident events (sudden cardiac death or fatal and nonfatal myocardial infarction). In this case-cohort design, the final sample contained 114 cases and 913 noncases.

RESULTS

Baseline distributions of cardiometabolic risk factors were significantly different between cases and noncases, with no detectable job strain-specific differences. However, cases with high job strain had higher monocyte chemoattractant protein-1, interleukin (IL)-8, and IL-18 compared with noncases with high job strain. High-sensitivity C-reactive protein, IL-6, and soluble intercellular adhesion molecule-1 were increased in cases versus noncases, regardless of work stress. Job strain was associated with incident coronary events in Cox proportional hazards models adjusted for age, sex, and survey (hazard ratio = 2.57, 95% confidence interval = 1.09-6.07) and after adjustment for CHD risk factors (2.35, 1.003-5.49). Adjustment for monocyte chemoattractant protein-1 or IL-8 increased this risk estimate by 14.5% or 9.4%, respectively, whereas adjustment for C-reactive protein and soluble intercellular adhesion molecule-1 led to decreased hazard ratios (-9.9% and -5.5%, respectively).

CONCLUSIONS

Job strain increased CHD risk in healthy workers; the associated inflammatory burden may contribute to stress-related coronary pathogenesis.

Association between MIF gene polymorphisms and carotid artery atherosclerosis

Atherosclerosis is a chronic inflammatory disorder. Macrophage migration inhibitory factor (MIF) is a potent cytokine that plays an important role in the regulation of immune responses. Polymorphisms including five- to eight-repeat CATT variants ((CATT)(5-8)) and G-173C in the promoter region of the MIF gene are associated with altered levels of MIF gene transcription. The purpose of the study is to investigate the relationship between promoter polymorphisms of the MIF gene and the severity of carotid artery atherosclerosis (CAA). The severity of CAA was assessed in 593 individuals with a history of ischemic stroke by using sonographic examination, and the MIF promoter polymorphisms of these individuals were genotyped. The carriage of (CATT)7 (compared to genotypes composed of (CATT)5, (CATT)6, or both), carriage of C allele (compared to GG), and carriage of the haplotype (CATT)7-C (compared to genotypes composed of (CATT)5-G, (CATT)6-G, or both) were significantly associated with an increase in the severity of CAA. We conclude that polymorphisms in the MIF gene promoter are associated with CAA severity in ischemic stroke patients. These genetic variants may serve as markers for individual susceptibility to CAA.

Macrophage migration inhibitory factor inhibition is deleterious for high-fat diet-induced cardiac dysfunction

Aims

Development of metabolic syndrome is associated with impaired cardiac performance, mitochondrial dysfunction and pro-inflammatory cytokine increase, such as the macrophage migration inhibitory factor MIF. Depending on conditions, MIF may exert both beneficial and deleterious effects on the myocardium. Therefore, we tested whether pharmacological inhibition of MIF prevented or worsened metabolic syndrome-induced myocardial dysfunction.

Methods and Results

C57BL/6J mice were fed for ten weeks with 60% fat-enriched diet (HFD) or normal diet (ND). MIF inhibition was obtained by injecting mice twice a week with ISO-1, for three consecutive weeks. Then, triglycerides, cholesterol, fat mass, glucose intolerance, insulin resistance, ex vivo cardiac contractility, animal energetic substrate utilization assessed by indirect calorimetry and mitochondrial respiration and biogenesis were evaluated. HFD led to fat mass increase, dyslipidemia, glucose intolerance and insulin resistance. ISO-1 did not alter these parameters. However, MIF inhibition was responsible for HFD-induced cardiac dysfunction worsening. Mouse capacity to increase oxygen consumption in response to exercise was reduced in HFD compared to ND, and further diminished in ISO-1-treated HFD group. Mitochondrial respiration was reduced in HFD mice, treated or not with ISO-1. Compared to ND, mitochondrial biogenesis signaling was upregulated in the HFD as demonstrated by mitochondrial DNA amount and PGC-1α expression. However, this increase in biogenesis was blocked by ISO-1 treatment.

Conclusion

MIF inhibition achieved by ISO-1 was responsible for a reduction in HFD-induced mitochondrial biogenesis signaling that could explain majored cardiac dysfunction observed in HFD mice treated with MIF inhibitor.

The vascular biology of macrophage migration inhibitory factor (MIF). Expression and effects in inflammation, atherogenesis and angiogenesis

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with chemokine-like functions. MIF is a critical mediator of the host immune and inflammatory response. Dysregulated MIF expression has been demonstrated to contribute to various acute and chronic inflammatory conditions as well as cancer development. More recently, MIF has been identified as an important pro-atherogenic factor. Its blockade could even aid plaque regression in advanced atherosclerosis. Promotion of atherogenic leukocyte recruitment processes has been recognised as a major underlying mechanism of MIF in vascular pathology. However, MIF's role in vascular biology is not limited to immune cell recruitment as recent evidence also points to a role for this mediator in neo-angiogenesis / vasculogenesis by endothelial cell activation and endothelial progenitor cell recruitment. On the basis of introducing MIF's chemokine-like functions, the current article focusses on MIF's role in vascular biology and pathology.

Job strain associated CRP is mediated by leisure time physical activity: results from the MONICA/KORA study

BACKGROUND

Psychological stress at work is considered a cardiac risk factor, yet whether it acts directly through neuroimmune processes, or indirectly by increasing behavioral risk factors, is uncertain. Cross-sectional associations between job strain and serum biomarkers of inflammation and endothelial dysfunction were investigated. Secondary analyses explored the role of psychosocial/cardiometabolic risk factors as mediators of job stress associated inflammation in healthy workers.

METHODS

Information on risk factors was obtained in standardized personal interviews of a subcohort of working participants in the MONICA/KORA population (n = 951). Work stress was measured by the Karasek job strain index. Biomarkers were measured from non-fasting venous blood. Multivariate regression analyses were used to examine the association of job strain with inflammatory biomarkers. Mediation analysis (Sobel test) was used to determine the effect of psychosocial risk factors on the association between job strain and C-reactive protein (CRP).

RESULTS

High job strain was reported by half (n = 482, 50.7%) of the study participants. While workers with high job strain were more likely to have adverse workplace conditions (competition with coworkers, job dissatisfaction and insecurity), sleeping problems, depressive symptoms, a Type A personality, and be physically inactive, no differences in cardiometabolic risk factors were detected. A strong and robust association between job strain and CRP was observed in age and sex adjusted models, as well as models adjusted for classic coronary heart disease risk factors (β = 0.39, p = 0.006 and β = 0.27, p = 0.03, respectively). Adjustment for physical activity abrogated this effect (β = 0.23, p = 0.07), and a mediating effect of physical activity on stress-associated inflammation was demonstrated (p = 0.04).

CONCLUSIONS

The analyses provide evidence for both a direct and an indirect effect of job strain on inflammation.

High postoperative blood levels of macrophage migration inhibitory factor are associated with less organ dysfunction in patients after cardiac surgery

Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine that exerts protective effects during myocardial ischemia/reperfusion injury. We hypothesized that elevated MIF levels in the early postoperative time course might be inversely associated with postoperative organ dysfunction as assessed by the simplified acute physiology score (SAPS) II and sequential organ failure assessment (SOFA) score in patients after cardiac surgery. A total of 52 cardiac surgical patients (mean age [± SD] 67 ± 10 years; EuroScore: 7) were enrolled in this monocenter, prospective observational study. Serum levels of MIF and clinical data were obtained after induction of anesthesia, at admission to the intensive care unit (ICU), 4 h after admission and at the first and second postoperative day. To characterize the magnitude of MIF release, we compared blood levels of samples from cardiac surgical patients with those obtained from healthy volunteers. We assessed patient outcomes using the SAPS II at postoperative d 1 and SOFA score for the first 3 d of the eventual ICU stay. Compared to healthy volunteers, patients had already exhibited elevated MIF levels prior to surgery (64 ± 50 versus 13 ± 17 ng/mL; p < 0.05). At admission to the ICU, MIF levels reached peak values (107 ± 95 ng/mL; p < 0.01 versus baseline) that decreased throughout the observation period and had already reached preoperative values 4 h later. Postoperative MIF values were inversely correlated with SAPS II and SOFA scores during the early postoperative stay. Moreover, MIF values on postoperative d 1 were related to the calculated cardiac power index (r = 0.420, p < 0.05). Elevated postoperative MIF levels are inversely correlated with organ dysfunction in patients after cardiac surgery.

Energy expenditure regulation via macrophage migration inhibitory factor in obesity and in vitro anti-macrophage migration inhibitory factor effect of Alpinia officinarum Hance extraction

OBJECTIVE

To compare the resting energy expenditure in different macrophage migration inhibitory factor (MIF) genotypes and to identify the in vitro effects of Alpinia officinarum Hance extract (AOHE) on MIF expression in obese and nonobese persons.

METHODS

In the fasting state, obese and nonobese persons were assessed for the measurement of resting energy expenditure rate (REE) by indirect calorimetry. We compared it with the expected amount ([REE measured by indirect calorimetry / predicted REE according to Harris Benedict equations] x 100). Participants were classified into those with normal REE (≥100) vs those with impaired REE (<100). Body composition was analyzed. Real-time polymerase chain reaction was performed using specific primer pairs for MIF messenger RNA, and β-actin was used as the internal control.

RESULTS

The study included 69 obese and 103 non-obese participants. The proportions of MIF genotypes were slightly different in obese and nonobese participants. However, the proportions of MIF genotypes were significantly different in participants with normal REE and those with low REE. The MIF gene was highly expressed in the obese group compared with MIF expression in the nonobese group. Body fat mass and MIF expression were higher in participants with the GG genotype than in the other genotype groups. MIF expression was inversely associated with REE in both groups (r = -0.36, P = .04). After treatment of peripheral blood mononuclear cells with AOHE, MIF expression differed according to MIF genotype.

CONCLUSIONS

Our results indicate that AOHE is a major modulator of MIF-dependent pathologic conditions in obesity and are consistent with mounting evidence that defines a regulating role for MIF in cytokine production in an inflammatory state in in vitro studies.

TGF-β1 content in atherosclerotic plaques, TGF-β1 serum concentrations and incident coronary events

BACKGROUND

We tested the hypothesis that high TGF-β1 content in atherosclerotic plaques and high TGF-β1 serum levels are associated with lower risk of coronary events in two independent prospective studies.

MATERIALS AND METHODS

In the prospective Athero-Express biobank study, total TGF-β1 plaque levels were measured in 632 atherosclerotic lesions from patients who underwent carotid endarterectomy. In a population-based case-cohort study within the Monitoring of trends and determinants in cardiovascular disease (MONICA)/Cooperative Health Research in the Region of Augsburg (KORA) Augsburg studies, baseline total TGF-β1 serum levels were measured in 333 individuals with and 1728 without incident coronary events.

RESULTS

Patients with TGF-β1 content in their plaques above the study median did not have a lower risk of coronary events than patients with lower TGF-β1 levels [adjusted HR (95% CI) 1·46 (0·83-2·53); P = 0·16; mean follow-up 2·6 ± 0·7 years] in the Athero-Express biobank study. Cox proportional hazard models adjusting for age, sex, body mass index, metabolic factors, lifestyle factors and survey did not reveal a significant association between TGF-β1 serum levels and incident coronary events [HR (95% CI) for increasing TGF-β1 tertiles 1·0, 1·22 (0·88-1·68), 1·13 (0·82-1·57); P = 0·47; mean follow-up: 10·8 ± 4·6 years] in the MONICA/KORA Augsburg studies.

CONCLUSION

Our results indicate that high TGF-β1 content in human atherosclerotic plaques and high serum levels of TGF-β1 are not associated with reduced risk of coronary events.

RANTES/CCL5 and risk for coronary events: results from the MONICA/KORA Augsburg case-cohort, Athero-Express and CARDIoGRAM studies

BACKGROUND

The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events.

METHODS AND FINDINGS

We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±4.8 years). Cox proportional hazard models adjusting for age, sex, body mass index, metabolic factors and lifestyle factors revealed no significant association between RANTES and incident coronary events (HR [95% CI] for increasing RANTES tertiles 1.0, 1.03 [0.75-1.42] and 1.11 [0.81-1.54]). None of six CCL5 single nucleotide polymorphisms and no common haplotype showed significant associations with coronary events. Also in the CARDIoGRAM study (>22,000 cases, >60,000 controls), none of these CCL5 SNPs was significantly associated with coronary artery disease. In the prospective Athero-Express biobank study, RANTES plaque levels were measured in 606 atherosclerotic lesions from patients who underwent carotid endarterectomy. RANTES content in atherosclerotic plaques was positively associated with macrophage infiltration and inversely associated with plaque calcification. However, there was no significant association between RANTES content in plaques and risk for coronary events (mean follow-up 2.8±0.8 years).

CONCLUSIONS

High RANTES plaque levels were associated with an unstable plaque phenotype. However, the absence of associations between (i) RANTES serum levels, (ii) CCL5 genotypes and (iii) RANTES content in carotid plaques and either coronary artery disease or incident coronary events in our cohorts suggests that RANTES may not be a novel coronary risk biomarker. However, the potential relevance of RANTES levels in platelet-poor plasma needs to be investigated in further studies.

Benzisothiazolones as modulators of macrophage migration inhibitory factor

Substituted N-phenylbenzisothiazolones have been investigated as inhibitors of the tautomerase activity of the proinflammatory cytokine MIF (macrophage migration inhibitory factor). Numerous compounds were found to possess antagonist activity in the low micromolar range with the most potent being the 6-hydroxy analog 1w. Compound 1w and the p-cyano analog 1c were also shown to exhibit significant inhibition of the binding of MIF to its transmembrane receptor CD74. Consistently, both compounds were also found to retard the MIF-dependent phosphorylation of ERK1/2 in human synovial fibroblasts.

Association of early repolarization pattern on ECG with risk of cardiac and all-cause mortality: a population-based prospective cohort study (MONICA/KORA)

BACKGROUND

Early repolarization pattern (ERP) on electrocardiogram was associated with idiopathic ventricular fibrillation and sudden cardiac arrest in a case-control study and with cardiovascular mortality in a Finnish community-based sample. We sought to determine ERP prevalence and its association with cardiac and all-cause mortality in a large, prospective, population-based case-cohort study (Monitoring of Cardiovascular Diseases and Conditions [MONICA]/KORA [Cooperative Health Research in the Region of Augsburg]) comprised of individuals of Central-European descent.

METHODS AND FINDINGS

Electrocardiograms of 1,945 participants aged 35-74 y, representing a source population of 6,213 individuals, were analyzed applying a case-cohort design. Mean follow-up was 18.9 y. Cause of death was ascertained by the 9th revision of the International Classification of Disease (ICD-9) codes as documented in death certificates. ERP-attributable effects on mortality were determined by a weighted Cox proportional hazard model adjusted for covariables. Prevalence of ERP was 13.1% in our study. ERP was associated with cardiac and all-cause mortality, most pronounced in those of younger age and male sex; a clear ERP-age interaction was detected (p = 0.005). Age-stratified analyses showed hazard ratios (HRs) for cardiac mortality of 1.96 (95% confidence interval [CI] 1.05-3.68, p = 0.035) for both sexes and 2.65 (95% CI 1.21-5.83, p = 0.015) for men between 35-54 y. An inferior localization of ERP further increased ERP-attributable cardiac mortality to HRs of 3.15 (95% CI 1.58-6.28, p = 0.001) for both sexes and to 4.27 (95% CI 1.90-9.61, p<0.001) for men between 35-54 y. HRs for all-cause mortality were weaker but reached significance.

CONCLUSIONS

We found a high prevalence of ERP in our population-based cohort of middle-aged individuals. ERP was associated with about a 2- to 4-fold increased risk of cardiac mortality in individuals between 35 and 54 y. An inferior localization of ERP was associated with a particularly increased risk. Please see later in the article for the Editors' Summary.

Macrophage migration inhibitory factor is a therapeutic target in treatment of non-insulin-dependent diabetes mellitus

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in the pathogenesis of a variety of autoimmune inflammatory diseases. Here, we investigated the role of MIF in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM) using MIF(-/-) mice and a mouse model of streptozotocin (STZ)-induced NIDDM. Following single injection of STZ, MIF(+/+) BALB/c mice showed a significant increase in blood glucose levels, developed polyuria, and succumbed to disease. In contrast, no such increase in blood glucose was observed in MIF(-/-) BALB/c mice treated with STZ. These mice produced significantly less inflammatory cytokines and resistin as compared with MIF(+/+) mice and failed to develop clinical disease. Finally, oral administration of a small-molecule MIF antagonist, CPSI-1306, to outbred ICR mice following induction of NIDDM significantly lowered blood glucose levels in the majority of animals, which was also associated with a significant reduction in the levels of the proinflammatory cytokines IL-6 and TNF-alpha in the sera. Taken together, these results demonstrate that MIF is involved in the pathogenesis of NIDDM and is a therapeutic target to treat this disease.

The macrophage migration inhibitory factor (MIF) gene polymorphism in Czech and Russian patients with myocardial infarction

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a cytokine implicated in early and advanced atherosclerosis. The aim of this study was to investigate whether polymorphism of MIF gene is associated with myocardial infarction (MI).

METHODS

Single nucleotide polymorphism (SNP) in MIF gene (-173G/C, rs755622) was investigated in Czech (n=219) and Russian (n=240) MI patients and population control from the same geographical areas (Czech, n=137; Russian, n=174). Further, another SNP (rs1007888) located within the 3' flanking region of the MIF gene was investigated in Czech MI patients and control subjects.

RESULTS

There were no significant differences in the distribution of MIF -173G/C genotypes, alleles or carriage rates between case and control groups in either populations. However, the GG genotype of the MIF SNP rs1007888 was associated with MI in Czech female patients (p=0.027).

CONCLUSIONS

Taken together with previous reports, our study suggests that particular MIF gene polymorphisms may contribute to MI susceptibility in females.

Sustained changes in lipid profile and macrophage migration inhibitory factor levels after anti-tumour necrosis factor therapy in rheumatoid arthritis

Background:

Macrophage migration inhibitory factor (MIF) has recently emerged as an important cytokine possibly linking rheumatoid arthritis (RA) and atherogenesis. Because atherogenesis is accelerated in RA this study was conducted to investigate whether anti-tumour necrosis factor (TNF) therapy could lead to sustained downregulation of systemic MIF levels and improvement in lipid profiles.

Methods:

Fifty RA patients with active disease (disease activity score in 28 joints (DAS28) ⩾3.2), who started adalimumab therapy at 40 mg every other week, were included. At baseline, weeks 16 and 52 serum levels of MIF and lipids were assessed. In addition, the DAS28 and serum C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were determined.

Results:

After 16 weeks of adalimumab therapy, both DAS28 and MIF levels were significantly decreased (p<0.001 and p = 0.020, respectively). This was sustained up to week 52 (p<0.001 and p = 0.012, respectively). CRP levels and ESR were significantly reduced after 16 and 52 weeks of adalimumab therapy (p<0.001). High-density lipoprotein cholesterol levels increased at week 16 (p<0.001), but returned to baseline at week 52. Apolipoprotein (apo) A-I levels increased at week 16 (p<0.001) and remained stable (p = 0.005). This resulted in an improved apo B/A-I ratio.

Conclusions:

The results underline the sustained downregulation of MIF as a potential new mechanism by which anti-TNF therapy might reduce vascular inflammation, and as such perhaps cardiovascular morbidity in RA patients. This hypothesis is supported by an improved apo B/A-I ratio as well as reduced CRP levels in these patients.

Chemokine-like functions of MIF in atherosclerosis

The cytokine macrophage migration inhibitory factor (MIF) is a unique pro-inflammatory regulator of many acute and chronic inflammatory diseases. In the pathogenesis of atherosclerosis, chronic inflammation of the arterial wall characterized by chemokine-mediated influx of leukocytes plays a central role. The contribution of MIF to atherosclerotic vascular disease has come into focus of many studies in recent years. MIF is highly expressed in macrophages and endothelial cells of different types of atherosclerotic plaques, and functional studies established the contribution of MIF to lesion progression and plaque inflammation. This proatherogenic effect may partly be explained by the finding that MIF regulates inflammatory cell recruitment to lesion areas. Similar to chemokines, MIF induces integrin-dependent arrest and transmigration of monocytes and T cells. These chemokine-like functions are mediated through interaction of MIF with the chemokine receptors CXCR2 and CXCR4 as a non-canonical ligand. In atherogenic monocyte recruitment, MIF-induced monocyte adhesion involves CD74 and CXCR2, which form a signaling receptor complex. In addition to lesion progression, MIF has been implicated in plaque destabilization, since MIF is predominantly expressed in vulnerable plaques and can induce collagen-degrading matrix metalloproteinases. The latter could be a relevant mechanism in atherosclerotic abdominal aneurysm formation, where MIF expression is correlated with aneurysmal expansion. In summary, MIF has been identified as an important regulator of atherosclerotic vascular disease with exceptional chemokine-like functions. Detailed analysis of the interaction of MIF with its receptors could provide valuable information for drug development for the anti-inflammatory treatment of established and unstable atherosclerosis.