Macrophage migration inhibitory factor urinary excretion revisited – MIF a potent predictor of the immunosuppressive treatment outcomes in patients with proliferative primary glomerulonephritis

Distinct patterns of serum and urine macrophage migration inhibitory factor kinetics predict death in sepsis: a prospective, observational clinical study

Macrophage migration inhibitory factor (MIF) has been considered as a biomarker in sepsis, however the predictive value of the pattern of its kinetics in the serum and in the urine has remained unclarified. It is also unclear whether the kinetics of MIF are different between males and females. We conducted a single-center prospective, observational study with repeated measurements of MIF in serum and urine on days 0, 2, and 4 from admission to the intensive care unit (ICU) in 50 adult septic patients. We found that in patients who died within 90 days, there was an increase in serum MIF level from day 0 to 4, whereas in the survivors there was rather a decrease (p = 0.018). The kinetics were sex-dependent as the same difference in the pattern was present in males (p = 0.014), but not in females (p = 0.418). We also found that urine MIF was markedly lower in patients who died than in survivors of sepsis (p < 0.050). Urine MIF levels did not show temporal changes: there was no meaningful difference between day 0 and 4. These results suggest that kinetics of serum MIF during the initial days from ICU admission can predict death, especially in male patients. Additionally, lower urine MIF levels can also indicate death without showing meaningful temporal kinetics.

Macrophage migration inhibitory factor levels are associated with disease activity and possible complications in membranous nephropathy

Membranous nephropathy (MN) is an autoimmune disease characterized by the deposition of immunoglobulin G (IgG) and complementary components in the epithelium of the glomerular capillary wall. Macrophage migration inhibitory factor (MIF) is an inflammatory mediator released by macrophages. MIF plays a key regulatory function in the pathogenesis of immune-mediated glomerulonephritis. This study aimed to investigate whether MIF level could be associated with the activity of MN. Plasma and urine samples from 57 MN patients and 20 healthy controls were collected. The MIF levels in plasma and urine were determined by an enzyme-linked immunosorbent assay (ELISA) kit. The expression of MIF in the renal specimens from 5 MN patients was detected by immunohistochemistry (IHC). The associations of the plasma and urinary levels of MIF and glomerular MIF expression with clinical and pathological characteristics were analyzed. It was revealed that with the increase of MIF levels in plasma and urine, the severity of renal pathological injury in MN patients gradually increased. Correlation analysis showed that the MIF levels in plasma were positively correlated with the platelet (PLT) count (r = 0.302, P = 0.022), and inversely correlated with the prothrombin time (PT) (r =  - 0.292, P = 0.028) in MN patients. The MIF levels in plasma were positively correlated with the C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) (r = 0.651, P < 0.0001; r = 0.669, P < 0.0001) in MN patients. The urinary levels of MIF were positively correlated with ESR (r = 0.562, P < 0.0001). IHC suggested that MIF was expressed in glomerular basement membrane and tubulointerstitial areas. MIF levels in plasma and urine could reflect the severity of MN, and MIF levels in plasma and urine could be associated with venous thrombosis and infectious complications in MN patients. The glomerular MIF expression could be used to indicate the activity of MN.

Co-Delivery of Dexamethasone and Captopril by α8 Integrin Antibodies Modified Liposome-PLGA Nanoparticle Hybrids for Targeted Anti-Inflammatory/Anti-Fibrosis Therapy of Glomerulonephritis

Purpose

Mesangial cells-mediated glomerulonephritis refers to a category of immunologically mediated glomerular injuries characterized by infiltration of circulating inflammatory cells, proliferation of mesangial cells, and the common pathological manifestation to the later stage is renal fibrosis, accompanied by excessive accumulation of extracellular matrix (ECM). Treatment regimens include glucocorticoids and immunosuppressive agents, but their off-target distribution causes severe systemic toxicity. Hence, specific co-delivery of “anti-inflammatory/anti-fibrosis” drugs to the glomerular mesangial cell (MC) region is expected to produce better therapeutic effects.

Methods

A novel kidney-targeted nanocarrier drug delivery system targeting MCs was constructed using passive targeting resulting from the difference in pore size between the glomerular endothelial layer and the basement membrane, and active targeting based on the specific binding of antibodies and antigens. Specifically, a liposome-nanoparticle hybrid (PLGA-LNHy) was formed by coating the surface of PLGA nanoparticles (NPs) with a phospholipid bilayer, and then PLGA-LNHy was co-modified with PEG and α8 integrin antibodies to obtain PLGA immunoliposomes (PLGA-ILs).

Results

The results showed that the obtained NPs had a core-shell structure, uniform and suitable particle size (119.1 ± 2.31 nm), low cytotoxicity, and good mesangial cell-entry ability, which can successfully accumulate in the glomerular MC region. Both dexamethasone (DXMS) and captopril (CAP) were loaded onto PLGA-ILs with a drug loading of 10.22 ± 1.00% for DXMS and 6.37 ± 0.25% for CAP (DXMS/CAP@PLGA-ILs). In vivo pharmacodynamics showed that DXMS/CAP@PLGA-ILs can effectively improve the pathological changes in the mesangial area and positive expression of proliferating cell nuclear antigen (PCNA) in glomeruli as well as reduce the expression of inflammatory factors, fibrotic factors and reactive oxygen species (ROS). Thus, renal inflammation and fibrosis were relieved.

Conclusion

We have provided a strategy to increase nanoparticle accumulation in MCs with the potential to implement regulatory effects of anti-inflammatory and anti-fibrosis in glomerulonephritis (GN).

Immune modulation by the macrophage migration inhibitory factor (MIF) family: D-dopachrome tautomerase (DDT) is not (always) a backup system

Human macrophage migration inhibition factor (MIF) is a protein with cytokine and chemokine properties that regulates a diverse range of physiological functions related to innate immunity and inflammation. Most research has focused on the role of MIF in different inflammatory diseases. D-dopachrome tautomerase (DDT), a different molecule with structural similarities to MIF, which shares receptors and biological functions, has recently been reported, but little is known about its roles and mechanisms. In this review, we sought to understand the similarities and differences between these molecules by summarizing what is known about their different structures, receptors and mechanisms regulating their expression and biological activities with an emphasis on immunological aspects.

MALDI-MSI Pilot Study Highlights Glomerular Deposits of Macrophage Migration Inhibitory Factor as a Possible Indicator of Response to Therapy in Membranous Nephropathy

PURPOSE

Membranous nephropathy (MN) is the most frequent cause of nephrotic syndrome in adults and the disease course is characterized by the "rule of third", with one-third of patients experiencing complete remission and the remaining experiencing relapses or progression of the disease. Additionally, the therapeutic approach is not standardized, leading to further heterogeneity in terms of response and outcome.

EXPERIMENTAL DESIGN

In this pilot study, MALDI-MSI analysis is performed on renal biopsies (n = 13) obtained from two homogeneous groups of patients, which differentially responded to the immunosuppressive treatments (Ponticelli regimen).

RESULTS

A signal at m/z 1303 displays the greatest discriminatory power when comparing the two groups and is observed to be of higher intensity in the glomeruli of the non-responding patients. The corresponding tryptic peptide is identified as macrophage migration inhibitory factor (MIF).

CONCLUSIONS AND CLINICAL RELEVANCE

Despite much effort being made in recent years to understand the pathogenesis of MN, a biomarker able to predict the outcome of these patients following therapeutic treatment is still lacking. Here, a protein (MIF), verified by immunohistochemistry, that can differentiate between these MN patients and could be a valuable starting point for a further study focused on verifying its predictive role in therapy response is highlighted.

CXCR7 Targeting and Its Major Disease Relevance

Chemokine receptors are the target of small peptide chemokines. They play various important roles in physiological and pathological processes. CXCR7, later renamed ACKR3, is a non-classical seven transmembrane-spanning receptor whose function as a signaling or non-signaling scavenger/decoy receptor is currently under debate. Even for cell signaling mechanisms, there has been inconsistency on whether CXCR7 couples to G-proteins or β-arrestins. Several reasons may contribute to this uncertainty or controversy. In one hand, it has been neglected that CXCR7 has more than five natural ligands and unfortunately, most of the prior research only studied SDF-1 (CXCL12) and/or I-TAC (CXCL11); on the other hand, there are mounting evidence supporting ligand and tissue bias for receptor signaling, but limited such information is available for CXCR7. In this review we focus on summarizing the endogenous and exogenous ligands of CXCR7, the main diseases related to CXCR7 and the biased signaling events happening on CXCR7. These three aspects of CXCR7 pharmacologic properties may explain why the contradicting opinions of whether CXCR7 is a signaling or non-signaling receptor exist. Further, potential new direction and perspective for the study of CXCR7 biology and pharmacology are highlighted.

Myocardial Expression of Macrophage Migration Inhibitory Factor in Patients with Heart Failure

Macrophage migration inhibitory factor (MIF) is a pleiotropic inflammatory protein and contributes to several different inflammatory and ischemic/hypoxic diseases. MIF was shown to be cardioprotective in experimental myocardial ischemia/reperfusion injury and its expression is regulated by the transcription factor hypoxia-inducible factor (HIF)-1α. We here report on MIF expression in the failing human heart and assess myocardial MIF in different types of cardiomyopathy. Myocardial tissue samples from n = 30 patients were analyzed by quantitative Real-Time PCR. MIF and HIF-1α mRNA expression was analyzed in myocardial samples from patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM) and from patients after heart transplantation (HTX). MIF expression was elevated in myocardial samples from patients with ICM compared to NICM. Transplanted hearts showed lower MIF levels compared to hearts from patients with ICM. Expression of HIF-1α was analyzed and was shown to be significantly increased in ICM patients compared to patients with NICM. MIF and HIF-1α mRNA is expressed in the human heart. MIF and HIF-1α expression depends on the underlying type of cardiomyopathy. Patients with ICM show increased myocardial MIF and HIF-1α expression.