MIF and D-DT are potential disease severity modifiers in male MS subjects

Pathogenic contribution of the Macrophage migration inhibitory factor family to major depressive disorder and emerging tailored therapeutic approaches

BACKGROUND

Immunoinflammatory disorders are often accompanied by depression. Here, we review the available preclinical and clinical studies suggesting a role for the pro-inflammatory cytokine Macrophage migration inhibitory factor (MIF) and the second member of the MIF family, D-dopachrome tautomerase (D-DT; DDT), in the pathogenesis of Major Depressive Disorders (MDD).

METHODS

We prepared a narrative review from a search on PubMed of studies pertaining to MDD and MIF, as for October 2019. Both humans and animal studies haves been considered.

RESULTS

Preclinical data show conflicting results on the role of endogenous MIF and DDT in depression. In contrast, several human studies show that circulating MIF levels tend to increase during the course of MDD. Higher levels of inflammatory biomarkers have also been associated with poorer responses to antidepressants and the levels of MIF significantly decrease after treatment, despite this may not be necessarily associated to an improvement in psychiatric symptoms.

LIMITATIONS

This is a narrative and not a systematic review of the literature on the involvement of MIF in MDD. We have highlighted studies performed in humans and in animal models, irrespective of population size and methodological approach.

CONCLUSIONS

This review highlights a role of MIF, and possibly DDT, in the pathogenesis of MDD. Whilst studies in animal models are discordant, the studies in patients with MDD convergently suggest that MIF plays a role in induction and maintenance of the disease. Additional studies are also needed on DDT that often displays synergistic function with MIF and their receptors.

MIF -173G/C polymorphism is associated with NMO disease severity

Our knowledge about genetic factors that drive the worsening of neuromyelitis optica (NMO) is limited. Herein, we analyzed the macrophage migration inhibitory factor (MIF) -173G/C functional polymorphism in NMO patients and controls. Our data reveal that the frequency of the high-expression MIF genotypes (CC/GC) did not differ between the two groups. However, frequency of this genotypes was elevated in patients diagnosed with both optic neuritis and myelitis compared with patients that were diagnosed with only one symptom. Furthermore, patients carrying the CC/CG genotypes had significantly higher disability score. We conclude that MIF is associated with NMO severity rather than susceptibility.

The Role of Macrophage Migration Inhibitory Factor in Alzheimer's Disease: Conventionally Pathogenetic or Unconventionally Protective?

Recent preclinical and clinical observations have offered relevant insights on the etiopathogenesis of late onset Alzheimer′s disease (AD) and upregulated immunoinflammatory events have been described as underlying mechanisms involved in the development of AD. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine produced by several cells of the innate and adaptive immune system, as well as non-immune cells. In the present review, we highlight experimental, genetic, and clinical studies on MIF in rodent models of AD and AD patients, and we discuss emerging therapeutic opportunities for tailored modulation of the activity of MIF, that may potentially be applied to AD patients. Dismantling the exact role of MIF and its receptors in AD may offer novel diagnostic and therapeutic opportunities in AD.

Transcriptomic analysis reveals moderate modulation of macrophage migration inhibitory factor superfamily genes in alcohol use disorders

Alcohol use disorder (AUD) is a primary, chronic and relapsing disease of brain reward, motivation and memory, which is associated with several comorbidities, including major depression and post-traumatic stress disorder. It has been revealed that Ibudilast (IBUD), a dual inhibitor of phosphodiesterase-4 and −10 and of macrophage migration inhibitory factor (MIF), exerts beneficial effects on AUD in rodent models and human patients. Therefore, IBUD has attracted increasing interest, with research focusing on the elucidation of the pathogenic role of MIF and its homologue, D-dopachrome tautomerase (DDT), in the pathogenesis and maintenance of AUD. By using DNA microarray analysis, the current study performed a transcriptomic expression analysis of MIF, DDT and their co-receptors, including CD74, C-X-C chemokine receptor (CXCR)2, CXCR4 and CXCR7 in patients with AUD. The results revealed that the transcriptomic levels of MIF, DDT and their receptors were superimposable in the prefrontal cortex of rodents and patients with AUD and human patients. Furthermore, peripheral blood cells from heavy drinkers exhibited a moderate increase in MIF and DDT levels, both at the baseline and following exposure to alcohol-associated cues, based on individual situations that included alcohol-related stimuli resulting in subsequent alcohol use (buying alcohol and being at a bar, watching others drink alcohol). Considering the overlapping effects of MIF and DDT, the inverse Fisher's χ² test was performed on unadjusted P-values to evaluate the combined effect of MIF and DDT. The results revealed a significant increase in these cytokines in heavy drinkers compared with controls (moderate drinkers). To the best of our knowledge, the present study demonstrated for the first time that MIF and DDT expression was upregulated in the blood of patients with AUD. These results therefore warrant further study to evaluate the role of MIF and DDT in the development and maintenance of AUD, to evaluate their use as biomarkers to predict the psychotherapeutic and pharmacological response of patients with AUD and for use as therapeutic targets.

D-dopachrome tautomerase from Japanese sea bass ( Lateolabrax japonicus) is a chemokine-like cytokine and functional homolog of macrophage migration inhibitory factor

D-dopachrome tautomerase (DDT), a member of the macrophage migration inhibitory factor (MIF) protein superfamily, is a newly described cytokine with chemokine-like characteristics. However, research on fish DDT remains limited. In this study, we identified a DDT homolog (LjDDT) from the Japanese sea bass, Lateolabrax japonicus. Sequence analysis showed that LjDDT had typical sequence features of known DDT and MIF homologs and was most closely related to DDT of rock bream ( Oplegnathus fasciatus). LjDDT transcripts were detected in all tested tissues of healthy Japanese sea bass, with the highest expression found in the liver. Upon infection with Vibrio harveyi, LjDDT transcripts were significantly down-regulated in the three tested tissues, including the liver, spleen, and head kidney. Recombinant LjDDT (rLjDDT) and the corresponding antibody (anti-rLjDDT) were subsequently prepared. The administration of 100 μg/g anti-rLjDDT had a statistically significant protective effect on the survival of V. harveyi-infected fish. Moreover, rLjDDT was able to induce the migration of monocytes/macrophages (MO/MФ) and lymphocytes both in vitro and in vivo, but without significant influence on the migration of neutrophils. rLjDDT exhibited chemotactic activity for lipopolysaccharide (LPS) -stimulated M1-type MO/ MΦ in vitro, but not for cAMP-stimulated M2-type MO/MΦ. Furthermore, the knockdown of LjCD74, but not LjCXCR4, significantly down-regulated the rLjDDT-enhanced migration of MO/MΦ and relieved the rLjMIF-inhibited migration of MO/MΦ. These results indicate that LjCD74 may be the major chemotactic receptor of LjDDT and LjMIF in Japanese sea bass MO/MΦ. Combined rLjDDT+ rLjMIF treatment had no significant effect on the migration of MsiRNA, LjCD74si-, or LjCXCR4sitreated MO/MΦ compared to the control group, suggesting that the roles of LjDDT and LjMIF may be antagonistic. In conclusion, our study demonstrates for the first time that DDT may play a role in the immune responses of fish against bacterial infection through chemotactic recruitment of MO/MΦ via mediation of CD74 as an antagonist of MIF.

In Silico and In Vivo Analysis of IL37 in Multiple Sclerosis Reveals Its Probable Homeostatic Role on the Clinical Activity, Disability, and Treatment with Fingolimod

We evaluated the in silico expression and circulating levels of interleukin (IL)37 in patients with different forms of multiple sclerosis (MS) and also upon treatment with different disease-modifying drugs. The combined interpretation of the resulting data strengthens and extends the current emerging concept that endogenous IL37 plays an important role in determining onset and progression of MS. The in silico analysis revealed that production of IL37 from cluster of differentiation (CD)4+ T cells from MS patients was reduced in vitro as compared to healthy controls. The analysis of the datasets also demonstrated that “higher” levels of IL37 production from PBMC entailed significant protection from MS relapses. In addition, the in vivo part of the study showed that IL37 was selectively augmented in the sera of MS patients during a relapse and that treatment with the high potency disease-modifying drug fingolimod significantly increased the frequency of patients with circulating blood levels of IL37 (6/9, 66%) as compared to patients receiving no treatment (n = 48) or platform therapy (n = 59) who had levels of IL37 below the limit of the sensitivity of the assay. This finding therefore anticipates that fingolimod may at least partially exert its beneficial effects in MS by upregulating the production of IL37.

Overexpression of Macrophage Migration Inhibitory Factor and Its Homologue D-Dopachrome Tautomerase as Negative Prognostic Factor in Neuroblastoma

Neuroblastoma (NB) represents one of the most frequent pediatric solid tumors. Macrophage migration inhibitory factor (MIF) is a cytokine exerting multiple biological functions. More recently, a second member of the MIF family of cytokine has been identified, the D-dopachrome tautomerase (DDT), that exerts several overlapping functions with MIF. Growing evidence suggests a key role for MIF and DDT in the development of cancer. The aim of this study is to characterize the prognostic value of MIF and DDT in NB. We show that higher expression levels of MIF and DDT in Stage 4 NB samples are associated with a poorer prognosis, independently of the presence of MYCN amplification. Moreover, higher levels of MIF are mostly enriched by Th1 cells, while lower levels of MIF are associated with an increased proportion of B cells, Cytotoxic T cells, Dendritic cells and Natural Killer T cells. We also show that treatment with the histone deacetylase (HDAC) inhibitor, vorinostat, of the NB cell line, SH-SY5Y, determines a significant reduction in the expression of both MIF and DDT. Finally, MIF and DDT inhibition by short interfering RNA is able to revert vincristine sensitivity in vitro. Overall, our data suggest that MIF exert pro-tumorigenic properties in NB, likely by dampening antigen presentation and cytotoxic immune responses, and we propose the HDAC inhibitors as a potential therapeutic strategy for NB patients.

A selective small-molecule inhibitor of macrophage migration inhibitory factor-2 (MIF-2), a MIF cytokine superfamily member, inhibits MIF-2 biological activity

Cytokine macrophage migration inhibitory factor-2 (MIF-2 or D-dopachrome tautomerase) is a recently characterized second member of the MIF cytokine superfamily in mammalian genomes. MIF-2 shares pro-inflammatory and tumorigenic properties with the clinical target MIF (MIF-1), but the precise contribution of MIF-2 to immune physiology or pathology is unclear. Like MIF-1, MIF-2 has intrinsic keto-enol tautomerase activity and mediates biological functions by engaging the cognate, common MIF family receptor CD74. Evidence that the catalytic site of MIF family cytokines has a structural role in receptor binding has prompted exploration of tautomerase inhibitors as potential biological antagonists and therapeutic agents, although few catalytic inhibitors inhibit receptor activation. Here we describe the discovery and biochemical characterization of a selective small-molecule inhibitor of MIF-2. An in silico screen of 1.6 million compounds targeting the MIF-2 tautomerase site yielded several hits for potential catalytic inhibitors of MIF-2 and identified 4-(3-carboxyphenyl)-2,5-pyridinedicarboxylic acid (4-CPPC) as the most functionally potent compound. We found that 4-CPPC has an enzymatic IC₅₀ of 27 μm and 17-fold selectivity for MIF-2 versus MIF-1. An in vitro binding assay for MIF-1/MIF-2 to the CD74 ectodomain (sCD74) indicated that 4-CPPC inhibits MIF-2-CD74 binding in a dose-dependent manner (0.01-10 μm) without influencing MIF-1-CD74 binding. Notably, 4-CPPC inhibited MIF-2-mediated activation of CD74 and reduced CD74-dependent signal transduction. These results open opportunities for development of more potent and pharmacologically auspicious MIF-2 inhibitors to investigate the distinct functions of this MIF family member in vivo.

Upregulated Expression of Macrophage Migration Inhibitory Factor, Its Analogue D-Dopachrome Tautomerase, and the CD44 Receptor in Peripheral CD4 T Cells from Clinically Isolated Syndrome Patients with Rapid Conversion to Clinical Defined Multiple Sclerosis

Background and objectives: Macrophage Migration Inhibitory Factor (MIF) and D-Dopachrome Tautomerase (DDT) are two pleiotropic and primarily, but not exclusively, proinflammatory cytokines belonging to the MIF family of cytokines that have recently been shown to be implicated in the pathogenesis of progressive forms of human progressive Multiple Sclerosis (MS) and the experimental model counterpart in rodents. Materials and Methods: We have presently evaluated a transcriptomic analysis of the expression of MIF, DDT, their receptors CD74 and CD44, and MIF co-receptors CXCR2, CXCR4, and CXCR7 in peripheral blood of patients with Clinically Isolated Syndrome (CIS), with rapid progression to clinical defined MS. Results: Our analysis reveals that MIF, DDT, and CD44 are overexpressed in CD4⁺ T cells from patients with CIS, as compared to healthy controls. Accordingly, a significant overlap was observed between the genes overexpressed in CD4⁺ T cells from patients with CIS and the genes belonging to the MIF regulatory network. This upregulated expression appeared to be unique for CD4⁺ T cells, as other immune cells including CD8⁺ T cells, B cells, and monocytes from these patients exhibited expression levels of these molecules that were superimposable to those observed in healthy controls. Conclusions: Overall, our data suggest that the overexpression MIF cytokine family signature may occur in CD4⁺ T cells from patients with CIS, and that this phenomenon may be implicated in the pathogenesis of the disease, offering the possibility to represent both a diagnostic marker and a therapeutic target.

Role of B cells and antibodies in multiple sclerosis

Multiple sclerosis (MS) is a chronically progressive auto-immune mediated inflammatory demyelinating disease of the central nervous system (CNS) which manifests as disturbances in sensorimotor function and cognitive impairment. Although believed to be a T-cell mediated disease, the role of B cells has recently become a central issue in MS pathogenesis. Both antibody dependent and independent theories have been suggested to play a role in the initiation of inflammatory demyelination. Antibody dependent mechanisms include formation of autoantibodies targeting specific tissues in the CNS and B cell antigen presentation to T cells, leading to subsequent activation and cytokine secretion. Antibody independent mechanisms entail formation of ectopic lymphoid structures, cytokine production and secretion of neurotoxic factors. Moreover, breach of peripheral tolerance mechanisms due to disturbances in regulatory T cell functioning has also been described. B cell depletion through anti-CD20 monoclonal antibody utilization and other immunomodulatory therapies have been promising in reducing episodes of relapse and slowing progression, further strengthening the concept that B cells and antibodies are significant players in formation of brain lesions in MS.

Dysregulation of cytokine coding genes in peripheral blood of bipolar patients

BACKGROUND

The role of immune response dysregulation has been previously noticed in the pathogenesis of bipolar disorder (BD).

METHODS

In the current investigation, we compared expression levels of eight cytokines and a chemokine (CXCL8) in the peripheral blood of BD patients and healthy subjects. All BD patients were in euthymic phase.

RESULTS

We found higher expression of IL-1B, IL-10, IFN-G, TNF-a, TGF-B and IL-2 in male patients compared with male controls (ExR=3.44, P<0.0001, ExR=2.54, P<0.0001; ExR=2.39, P<0.0001; ExR=2.74, P<0.0001; ExR=2.32, P<0.0001; ExR=1.87, P = 0.04 respectively). For these cytokines, no significant differences were found between female patients and female controls. While expression of IL-6 was higher in male patients compared with male controls (ExR=2.07, P = 0.006), in female subjects the opposite trend was detected (ExR=0.44, P = 0.02). However, no significant difference was detected between female subjects. Expression levels of IL-17 were not different between patients and controls or between any subgroups of them. We found significant correlations between expression of IFN-G and age at disease onset (R = 0.25, P = 0.04) as well as expression of CXCL8 and both age of patients and age at disease onset (R = 0.26, P = 0.03; R = 0.25, P = 0.04). Moreover, inverse correlation was detected between expression of TNF-a and age in control group (R=-0.34, P = 0.008).

CONCLUSION

Combination of transcript levels of six genes could differentiate BD patients from healthy subjects with diagnostic power of 0.85 (Sensitivity=78%, Specificity=80% and P<0.0001). The current investigation highlights the role of cytokine coding genes in the pathogenesis of BD and potentiates them as diagnostic biomarkers.

Macrophage migration inhibitory factor (MIF) as a therapeutic target for rheumatoid arthritis and systemic lupus erythematosus

Introduction. Macrophage migration inhibitory factor (MIF) is a pleiotropic inflammatory cytokine with upstream regulatory roles in innate and adaptive immunity and is implicated in the pathogenesis of autoimmune diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Several classes of MIF inhibitors such as small molecule inhibitors and peptide inhibitors are in clinical development. Areas covered. The role of MIF in the pathogenesis of RA and SLE is examined; the authors review the structure, physiology and signaling characteristics of MIF and the related cytokine D-DT/MIF-2. The preclinical and clinical trial data for MIF inhibitors are also reviewed; information was retrieved from PubMed and ClinicalTrials.gov using the keywords MIF, D-DT/MIF-2, CD74, CD44, CXCR2, CXCR4, Jab-1, rheumatoid arthritis, systemic lupus erythematosus, MIF inhibitor, small molecule, anti-MIF, anti-CD74, and peptide inhibitor. Expert opinion. Studies in mice and in humans demonstrate the therapeutic potential of MIF inhibition for RA and SLE. MIF- directed approaches could be particularly efficacious in patients with high expression MIF genetic polymorphisms. In patients with RA and SLE and high expression MIF alleles, targeted MIF inhibition could be a precision medicine approach to treatment. Anti-MIF pharmacotherapies could also be steroid-sparing in patients with chronic glucocorticoid dependence or refractory autoimmune disease.

MIF/CD74 axis participates in inflammatory activation of Schwann cells following sciatic nerve injury

Based on deep RNA sequencing of distal segments of lesioned sciatic nerves, a huge number of differentially expression genes (DEGs) were thus obtained and functionally analyzed. The inflammatory response was denoted as one of most significant biological processes following sciatic nerve injury. In the present study, ingenuity pathway analysis (IPA) demonstrated that macrophage migration inhibitory factor (MIF) was identified as a core regulator of inflammatory response through interaction with CD74 membrane receptor. By establishment of rat sciatic nerve transection model, we displayed that MIF was upregulated following sciatic nerve axotomy, in colocalization with Schwann cells (SCs). MIF promoted migration, proliferation, together with inflammatory responses of SCs in vitro. Immunoprecipitation showed that MIF interacted with CD74 receptor, through which to activate intracellular ERK and JNK signaling pathways. Interference of CD74 receptor using specific siRNA showed that the transcription of proinflammatory cytokines including TNF-α, IL-1β, as well as cytokine receptor TLR4 in SCs was significantly attenuated, supporting an participation of MIF/CD74 signal axis in SCs inflammatory response. The data provide a novel role of MIF in eliciting inflammatory response of peripheral nerve injury, which might be beneficial for precise therapy of peripheral nerve inflammation.

Quantitative proteomic analyses of CD4+ and CD8+ T cells reveal differentially expressed proteins in multiple sclerosis patients and healthy controls

Background

Multiple sclerosis (MS) is an autoimmune, neuroinflammatory disease, with an unclear etiology. However, T cells play a central role in the pathogenesis by crossing the blood–brain-barrier, leading to inflammation of the central nervous system and demyelination of the protective sheath surrounding the nerve fibers. MS has a complex inheritance pattern, and several studies indicate that gene interactions with environmental factors contribute to disease onset.

Methods

In the current study, we evaluated T cell dysregulation at the protein level using electrospray liquid chromatography–tandem mass spectrometry to get novel insights into immune-cell processes in MS. We have analyzed the proteomic profiles of CD4⁺ and CD8⁺ T cells purified from whole blood from 13 newly diagnosed, treatment-naive female patients with relapsing–remitting MS and 14 age- and sex-matched healthy controls.

Results

An overall higher protein abundance was observed in both CD4⁺ and CD8⁺ T cells from MS patients when compared to healthy controls. The differentially expressed proteins were enriched for T-cell specific activation pathways, especially CTLA4 and CD28 signaling in CD4⁺ T cells. When selectively analyzing proteins expressed from the genes most proximal to > 200 non-HLA MS susceptibility polymorphisms, we observed differential expression of eight proteins in T cells between MS patients and healthy controls, and there was a correlation between the genotype at three MS genetic risk loci and protein expressed from proximal genes.

Conclusion

Our study provides evidence for proteomic differences in T cells from relapsing–remitting MS patients compared to healthy controls and also identifies dysregulation of proteins encoded from MS susceptibility genes.

Electronic supplementary material

The online version of this article (10.1186/s12014-019-9241-5) contains supplementary material, which is available to authorized users.

Correlation between Plasma Macrophage Migration Inhibitory Factor Levels and Long-Term Prognosis in Patients with Acute Myocardial Infarction Complicated with Diabetes

Macrophage migration inhibitory factor (MIF), a widely expressed pleiotropic cytokine, is reportedly involved in several cardiovascular diseases, in addition to inflammatory diseases. Plasma MIF levels are elevated in the early phase of acute cardiac infarction. This study is aimed at investigating the correlation between plasma MIF levels and cardiac function and prognosis in patients with acute ST-segment elevation myocardial infarction (STEMI) with or without diabetes mellitus. Overall, 204 patients with STEMI who underwent emergency percutaneous coronary intervention were enrolled: 57 and 147 patients in the diabetes and nondiabetes STEMI groups, respectively. Sixty-five healthy people were selected as controls. Plasma MIF levels were measured at the time of diagnosis. Basic clinical data and echocardiographic findings within 72 h of admission were collected. Patients were followed up, and echocardiograms were reviewed at the 12-month follow-up. Plasma MIF levels were significantly higher in the diabetes and nondiabetes STEMI groups than in the control group and in patients with Killip grade ≥ II STEMI than in those with Killip grade I. Plasma MIF levels were negatively correlated with the left ventricular ejection fraction (LVEF) of myocardial infarction in patients with or without diabetes in the acute phase of infarction, whereas the left ventricular diastolic dysfunction (LVDD) was positively correlated. MIF levels in the nondiabetes STEMI group were positively correlated with N-terminal pro-b-type natriuretic peptide levels and were associated with LVEF and LVDD at the 12-month follow-up. The risk of adverse cardiovascular and cerebrovascular events was significantly higher in the MIF high-level group (≥52.7 ng/mL) than in the nondiabetes STEMI group 36 months after presentation. Thus, MIF levels in STEMI patients with or without diabetes can reflect acute cardiac function. In STEMI patients without diabetes, MIF levels can also indicate cardiac function and long-term prognosis at the 12-month follow-up.

Macrophage migration inhibitory factor regulates innate γδ T-cell responses via IL-17 expression

T cells expressing invariant γδ antigen receptors (γδ T cells) bridge innate and adaptive immunity and facilitate barrier responses to pathogens. Macrophage migration inhibitory factor (MIF) is an upstream mediator of host defense that up-regulates the expression of pattern recognition receptors and sustains inflammatory responses by inhibiting activation-induced apoptosis in monocytes and macrophages. Surprisingly, Mif^-/- γδ T cells, when compared with wild type, were observed to produce >10-fold higher levels of the proinflammatory cytokine IL-17 after stimulation with gram-positive exotoxins. High-IL-17 expression was associated with the characteristic features of IL-17-producing γδ T (γδ17) cells, including expression of IL-23R, IL-1R1, and the transcription factors RORγt and Sox13. In the gram-positive model of shock mediated by toxic shock syndrome toxin (TSST-1), Mif^-/- mice succumbed to death more quickly with increased pulmonary neutrophil accumulation and higher production of cytokines, including IL-1β and IL-23. Mif^-/- γδ T cells also produced high levels of IL-17 in response to Mycobacterium lipomannan, and depletion of γδ T cells improved survival from acutely lethal Mycobacterium infection or TSST-1 administration. These data indicate that MIF deficiency is associated with a compensatory amplification of γδ17 cell responses, with implications for innate immunity and IL-17-mediated pathology in situations such as gram-positive toxic shock or Mycobacterium infection.-Kim, H. K., Garcia, A. B., Siu, E., Tilstam, P., Das, R., Roberts, S., Leng, L., Bucala, R. Macrophage migration inhibitory factor regulates innate γδ T-cell responses via IL-17 expression.

Increased CD74 binding and EAE treatment efficacy of a modified DRα1 molecular construct

Multiple sclerosis (MS) is a demyelinating and degenerative disease of the central nervous system (CNS) with a strong inflammatory component that affects more than 2 million people worldwide (and at least 400,000 in the United States). In MS, macrophage migration inhibitory factor (MIF) and D-dopachrome tautomerase (D-DT) enhance the inflammatory event as a result of their interaction with their cognate receptor CD74. Therefore, the search for new agents aimed at blocking this interaction is critical for therapeutic purposes and will be of paramount importance for the treatment of MS. DRα1-MOG-35-55 constructs have been demonstrated to be effective in the treatment of experimental autoimmune encephalomyelitis (EAE) a mouse model for MS. This effect is directly correlated with the binding to its cell surface receptor, CD74, apparently preventing or blocking the binding of two inflammatory factors, MIF and D-DT. Here we report that a single amino acid substitution (L50Q) in the DRα1 domain of the human and mouse DRα1-MOG-35-55 constructs (notated as DRhQ and DRmQ, respectively) possessed increased affinity for CD74, a greater capacity to block MIF binding, the ability to inhibit pERK1/2 signaling and increased therapeutic activity in mice with EAE. These data suggest that binding affinity for CD74 could serve as an in vitro indicator of biological potency of DRhQ and thus support its possible clinical utility as an effective therapy for MS and perhaps other diseases in which there is an inflammatory reaction driven by MIF and D-DT.

Mesenchymal stem cell-based therapy for autoimmune diseases: emerging roles of extracellular vesicles

In autoimmune disease body's own immune system knows healthy cells as undesired and foreign cells. Over 80 types of autoimmune diseases have been recognized. Currently, at clinical practice, treatment strategies for autoimmune disorders are based on relieving symptoms and preventing difficulties. In other words, there is no effective and useful therapy up to now. It has been well-known that mesenchymal stem cells (MSCs) possess immunomodulatory effects. This strongly suggests that MSCs might be as a novel modality for treatment of autoimmune diseases. Supporting this notion a few preclinical and clinical studies indicate that MSCs ameliorate autoimmune disorders. Interestingly, it has been found that the beneficial effects of MSCs in autoimmune disorders are not relying only on direct cell-to-cell communication but on their capability to produce a broad range of paracrine factors including growth factors, cytokines and extracellular vehicles (EVs). EVs are multi-signal messengers that play a serious role in intercellular signaling through carrying cargo such as mRNA, miRNA, and proteins. Numerous studies have shown that MSC-derived EVs are able to mimic the effects of the cell of origin on immune cells. In this review, we discuss the current studies dealing with MSC-based therapies in autoimmune diseases and provide a vision and highlight in order to introduce MSC-derived EVs as an alternative and emerging modality for autoimmune disorders.

Analysis of serum macrophage migration inhibitory factor and D-dopachrome tautomerase in systemic sclerosis

Objectives

Macrophage migration inhibitory factor (MIF) and D‐dopachrome tautomerase (DDT), members of the same cytokine superfamily, are linked to the pathogenesis of a number of inflammatory diseases. The aim of this study was to investigate their clinical relevance in systemic sclerosis (SSc).

Methods

Serum MIF and DDT were quantified in 105 SSc patients by ELISA and levels compared to healthy controls (HC) (47) and patients with systemic lupus erythematosus (SLE) (184). Clinical parameters included organ involvement, serum laboratory markers and results of pulmonary function tests, and overall disease activity assessed using the European Scleroderma Trials and Research group (EUSTAR) activity index.

Results

There was no significant difference in serum DDT concentrations between patients with SSc and HC. However, serum MIF was significantly increased in SSc compared to both HC and SLE cohorts. Serum MIF was increased in SSc patients with low forced vital capacity (FVC) and was also associated with the use of angiotensin II receptor blockers and beta blockers in SSc, confirmed after adjusting for the presence of systemic hypertension and low FVC. Serum DDT was significantly higher in SSc patients with low FEV1 and negatively correlated with EUSTAR score, particularly in patients with limited disease.

Conclusion

Although not significantly linked to specific clinical parameters, serum MIF was significantly higher in SSc patients than in HC and SLE patients, suggesting a fundamental role for MIF in SSc. DDT, while closely related to MIF, did not show a similar expression profile, suggesting functional differences between these molecules.

Role of MIF and D-DT in immune-inflammatory, autoimmune, and chronic respiratory diseases: from pathogenic factors to therapeutic targets

Macrophage migration inhibitory factor (MIF) is a protein that acts as a cytokine-, enzyme-, endocrine- and chaperon-like molecule. It binds to the cell-surface receptor CD74 in association with CD44, which activates the downstream signal transduction pathway. In addition, MIF acts also as a noncognate ligand for C-X-C chemokine receptor type 2 (CXCR2), type 4 (CXCR4), and type 7 (CXCR7). Recently, D-dopachrome tautomerase (D-DT), a second member of the MIF superfamily, was identified. From a pharmacological and clinical point of view, the nonredundant biological properties of MIF and D-DT anticipate potential synergisms from their simultaneous inhibition. Here, we focus on the role of MIF and D-DT in human immune-inflammatory, autoimmune, and chronic respiratory diseases, providing an update on the progress made in the identification of specific small-molecule inhibitors of these proteins.

From Systemic Inflammation to Neuroinflammation: The Case of Neurolupus

It took decades to arrive at the general consensus dismissing the notion that the immune system is independent of the central nervous system. In the case of uncontrolled systemic inflammation, the relationship between the two systems is thrown off balance and results in cognitive and emotional impairment. It is specifically true for autoimmune pathologies where the central nervous system is affected as a result of systemic inflammation. Along with boosting circulating cytokine levels, systemic inflammation can lead to aberrant brain-resident immune cell activation, leakage of the blood⁻brain barrier, and the production of circulating antibodies that cross-react with brain antigens. One of the most disabling autoimmune pathologies known to have an effect on the central nervous system secondary to the systemic disease is systemic lupus erythematosus. Its neuropsychiatric expression has been extensively studied in lupus-like disease murine models that develop an autoimmunity-associated behavioral syndrome. These models are very useful for studying how the peripheral immune system and systemic inflammation can influence brain functions. In this review, we summarize the experimental data reported on murine models developing autoimmune diseases and systemic inflammation, and we explore the underlying mechanisms explaining how systemic inflammation can result in behavioral deficits, with a special focus on in vivo neuroimaging techniques.

Genetic Variant rs755622 Regulates Expression of the Multiple Sclerosis Severity Modifier D-Dopachrome Tautomerase in a Sex-Specific Way

Multiple sclerosis (MS) is a sex-specific autoimmune disease involving central nervous system. Previous studies determined that macrophage migration inhibitory factor (MIF) and its homologue D-dopachrome tautomerase (DDT) sex-specifically affect MS progression. Moreover, other studies reported that rs755622 polymorphism in promoter region of MIF gene is associated with risk of MS and affects the promoter activity to regulate MIF expression in a sex-specific way. Given that MIF and DDT share a part of promoter sequence, we surmise that rs755622 can also regulate DDT expression in a sex-specific way. However, this has not yet been studied. Here, we used five large-scale expression quantitative trait loci (eQTLs) and two RNA-seq datasets from brain and blood to assess the potential influence of rs755622 variant on expression of DDT in different genders by the linear regression and differential expression analysis. The results show that the minor allele frequency of rs755622 and expression of DDT are significantly increased in males for MS subjects and this minor allele variant can significantly upregulate DDT expression for males but not females, which suggests that the regulation of DDT expression level by rs755622 can affect MS progression in males. These findings further support and expand conclusions of previous studies and may help to better understand the mechanisms of MS.

Structural Plasticity in the C-Terminal Region of Macrophage Migration Inhibitory Factor-2 Is Associated with an Induced Fit Mechanism for a Selective Inhibitor

We report the first reversible and selective small molecule inhibitor of pro-inflammatory protein macrophage migration inhibitory factor-2 (also known as MIF-2 or d-DT). 4-(3-Carboxyphenyl)-2,5-pyridinedicarboxylic acid (4-CPPC) shows competitive binding with a 13-fold selectivity for human MIF-2 versus human MIF-1. The crystal structure of MIF-2 complexed with 4-CPPC reveals an induced fit mechanism that is not observed in the numerous MIF-1/inhibitor complexes. Crystallographic analysis demonstrates the structural source of 4-CPPC binding and selectivity for MIF-2. 4-CPPC can be employed to reveal previously unrecognized functions of MIF-1 in biological systems in which both MIF-1 and MIF-2 are expressed, to improve our knowledge of the MIF family of proteins, and to provide new mechanistic insights that can be utilized for the development of potent and selective pharmacological modulators of MIF-2.

Small-molecule inhibitors of macrophage migration inhibitory factor (MIF) as an emerging class of therapeutics for immune disorders

Macrophage migration inhibitory factor (MIF) is an important cytokine for which an increasing number of functions is being described in the pathogenesis of inflammation and cancer. Nevertheless, the availability of potent and druglike MIF inhibitors that are well-characterized in relevant disease models remains limited. Development of highly potent and selective small-molecule MIF inhibitors and validation of their use in relevant disease models will advance drug discovery. In this review, we provide an overview of recent advances in the identification of MIF as a pharmacological target in the pathogenesis of inflammatory diseases and cancer. We also give an overview of the current developments in the discovery and design of small-molecule MIF inhibitors and define future aims in this field.

Overexpression of macrophage migration inhibitory factor and functionally-related genes, D-DT, CD74, CD44, CXCR2 and CXCR4, in glioblastoma

The macrophage migration inhibition factor (MIF) is a cytokine with multiple biological functions, including the cancer-associated processes, cell cycle deregulation, angiogenesis and metastatization. The present study investigated the expression of MIF and its functionally associated genes (D-DT, CD74, CD44, CXCR2 and CXCR4) in glioblastoma multiforme (GBM). The data were obtained from The Cancer Genome Atlas databank, through the cBioportal web-based utility (cbioportal.org/). A significant increase was observed in the majority of these genes in GBM samples compared with lower grade gliomas, however no significant correlation among the selected genes and the overall survival of the patients was identified. In contrast, the expression of MIF exhibited a trend toward an increase in overall survival and a significant increase of MIF expression was observed in samples of patients who underwent neoadjuvant treatment. In conclusion these data indicate that MIF and its receptors are involved in GBM progression and maintenance. Deciphering the precise biological significance in GBM would favor the adoption of tailored approaches to modulate the function of MIF and its associated genes for the treatment of the disease.

Contribution of the macrophage migration inhibitory factor superfamily of cytokines in the pathogenesis of preclinical and human multiple sclerosis: In silico and in vivo evidences

Macrophage migration inhibitory factor (MIF) is a cytokine with pleiotropic actions involved in the pathogenesis of autoimmune disorders, including Multiple Sclerosis (MS). We have first evaluated in silico the involvement of MIF, its homologue D-DT, and the receptors CD74, CD44, CXCR2 and CXCR4 in encephalitogenic T cells from a mouse model of MS, the Experimental Allergic Encephalomyelitis (EAE), as well as in circulating T helper cells from MS patients. We show an upregulation of the receptors involved in MIF signaling both in the animal model and in patients. Also, a significant increase in MIF receptors is found in the CNS lesions associated to MS. Finally, the specific inhibitor of MIF, ISO-1, improved both ex vivo and in vivo the features of EAE. Overall, our data indicate that there is a significant involvement of the MIF pathway in MS ethiopathogenesis and that interventions specifically blocking MIF receptors may represent useful therapeutic approaches in the clinical setting.

Atypical microdeletion in 22q11 deletion syndrome reveals new candidate causative genes: A case report and literature review

RATIONALE

22q11 deletion syndrome, the most common chromosomal microdeletion disease, is caused by megabase-sized deletions on chromosome 22q11.2. It is characterized by a wide spectrum of congenital anomalies in velopharyngeal and facial, cardiac, genitourinary, vertebroskeletal, respiratory, digestive, and central nervous systems. Phenotype-genotype studies have revealed several causative genes that regulate the development of the third and fourth pharyngeal arches in human. However, the exact pathogenesis of this syndrome remains unknown. Herein, we report a case of 22q11 deletion syndrome with an atypical microdeletion of 125 kb.

PATIENT CONCERNS

A 15-year-old Chinese girl presented with symptoms of facial dysmorphia, cardiac defects, velopharyngeal insufficiency, splenomegaly, immunodeficiency, and thrombocytopenia.

DIAGNOSES

Microarray analysis revealed a 22q11.23 deletion of 125 kb (chromosome 22: 24276973-24402263), suggesting the diagnosis of 22q11 deletion syndrome. The haploinsufficient genes included GSTT2B, GSTT2, DDTL, DDT, GSTTP1, LOC391322, GSTT1, and GSTTP2.

INTERVENTIONS

The patient was administrated glucocorticoids and calcium supplements.

OUTCOMES

No epistaxis or petechiae episode occurred during the follow-up; her platelet count ranged between 60 × 10 and 80 × 10/L.

LESSONS

Although none of the previous reported causative genes were affected in the patient, her clinical manifestations were typical of 22q11 deletion syndrome, apart from her progressive splenomegaly. This case indicated 8 new candidate pathogenic genes for 22q11 deletion syndrome. Given that the loss of these genes was sufficient to induce 22q11DS defects, whether these genes directly influence the pathogenesis of 22q11DS or through interactions with known hotspot mutations is worthy of research.