Elevated IL-4 and IFN-γ Levels in Muscle Tissue of Patients with Dermatomyositis

Increased expression of the p-STAT3/IL-17 signaling pathway in patients with dermatomyositis

OBJECTIVES

The aim is to explore the roles of phosphorylated signal transduction and activator of transcription 3 (p-STAT3) and interleukin (IL)-17 in patients with dermatomyositis (DM).

METHODS

A total of 20 DM patients and 12 healthy controls were enrolled. Flow cytometry combined with counting was used to detect the number of Th17 cells. Western blotting and immunohistochemistry were used to examine the muscle levels of p-STAT3 and IL-17, and serum levels of IL-17 were measured by enzyme-linked immunosorbent assays.

RESULTS

Muscle p-STAT3 and IL-17 levels, the number of Th17 cells, and serum IL-17 levels were markedly increased in DM. p-STAT3 and IL-17 were co-expressed in the muscle of DM patients. The p-STAT3 levels were correlated with the number of Th17 cells as well as muscle and serum IL-17 levels. The correlations of the p-STAT3 level with elevated levels of transaminases, myocardial enzymes, and the health assessment questionnaire score were significantly positive, while the correlation with manual muscle testing-8 was significantly negative. A receiver operating characteristic curve indicated the good predictive value of p-STAT3 for the occurrence of DM.

CONCLUSIONS

The increased p-STAT3/IL-17 signaling pathway activation in DM patients may induce muscle inflammation and necrosis, and it may be a potential target for DM.

Major histocompatibility complex I-induced endoplasmic reticulum stress mediates the secretion of pro-inflammatory muscle-derived cytokines

Major histocompatibility complex (MHC) I is an important component of intracellular antigen presentation. However, improper expression of MHC I upon the cell surface has been associated with several autoimmune diseases. Myositis is a rare acquired autoimmune disease which targets skeletal muscle, and MHC I overexpression on the surface of muscle fibres and immune cell infiltration are clinical hallmarks. MHC I overexpression may have an important pathogenic role, mediated by the activation of the endoplasmic reticulum (ER) stress response. Given the evidence that muscle is a diverse source of cytokines, we aimed to investigate whether MHC I overexpression can modify the profile of muscle-derived cytokines and what role the ER stress pathway may play. Using C2C12 myoblasts we overexpressed MHC I with a H-2k^b vector in the presence or absence of salubrinal an ER stress pathway modifying compound. MHC I overexpression induced ER stress pathway activation and elevated cytokine gene expression. MHC I overexpression caused significant release of cytokines and chemokines, which was attenuated in the presence of salubrinal. Conditioned media from MHC I overexpressing cells induced in vitro T-cell chemotaxis, atrophy of healthy myotubes and modified mitochondrial function, features which were attenuated in the presence of salubrinal. Collectively, these data suggest that MHC I overexpression can induce pro-inflammatory cytokine/chemokine release from C2C12 myoblasts, a process which appears to be mediated in-part by the ER stress pathway.

Past, Present, and Future in Dermatomyositis Therapeutics

Purpose of review

This review highlights current and emerging pharmacologic therapies for the treatment of dermatomyositis (DM). Current clinical evidence, in addition to recently published and ongoing clinical trials for various drugs in development, are summarized in this review.

Recent findings

There has been significant progress in the research and development of potential treatments in DM. The FDA recently approved Octagam® 10% Immune Globulin Intravenous (IVIg) for the treatment of DM. Several drug targets are being explored as viable therapeutic options in phase 2 and phase 3 clinical trials; at the forefront of these are JAK inhibitors (tofacitinib and baricitinib) and T-cell co-stimulation blockers (i.e. abatacept). In addition, clinical trials are currently under way for therapeutics targeting novel molecular pathways, including immunoproteasome inhibitors, anti-B cell therapy, anti-interferon drugs, complement inhibitors, and phosphodiesterase-4 inhibitors.

Summary

With the large number of clinical trials, multiple novel therapeutics in development, and improved classification and outcome measures, the treatment landscape for DM will continue to rapidly evolve in the coming years as more options become available.

Hsp90 as a Myokine: Its Association with Systemic Inflammation after Exercise Interventions in Patients with Myositis and Healthy Subjects

Compelling evidence supports the health benefits of physical exercise on the immune system, possibly through the molecules secreted by the skeletal muscles known as myokines. Herein, we assessed the impact of exercise interventions on plasma Heat shock protein 90 (Hsp90) levels in 27 patients with idiopathic inflammatory myopathies (IIM) compared with 23 IIM patients treated with standard-of-care immunosuppressive therapy only, and in 18 healthy subjects undergoing strenuous eccentric exercise, and their associations with the traditional serum markers of muscle damage and inflammation. In contrast to IIM patients treated with pharmacotherapy only, in whom we demonstrated a significant decrease in Hsp90 over 24 weeks, the 24-week exercise program resulted in a stabilization of Hsp90 levels. These changes in Hsp90 levels were associated with changes in several inflammatory cytokines/chemokines involved in the pathogenesis of IIM or muscle regeneration in general. Strenuous eccentric exercise in healthy volunteers induced a brief increase in Hsp90 levels with a subsequent return to baseline levels at 14 days after the exercise, with less pronounced correlations to systemic inflammation. In this study, we identified Hsp90 as a potential myokine and mediator for exercise-induced immune response and as a potential biomarker predicting improvement after physiotherapy in muscle endurance in IIM.

A novel model of dermatomyositis induced by membrane antigen and calciphylaxis in rats

Dermatomyositis (DM) is a severe autoimmune disease of the connective tissue characterized by inflammatory and degenerative changes in the skin and muscle. However, the lack of experimental models of DM represents a challenge for the development of effective drugs. The aim of the present study was to establish a pharmacodynamic rat model of DM that would recapitulate the clinical manifestation seen in patients. The DM model was established using membrane antigen-induced autoimmune injury, followed by toxin-induced subcutaneous calciphylaxis. The rats were divided into five groups and were subcutaneously injected with membrane antigen. Of these, four antigen-immunized groups then received dihydrotestosterone (DHT), iron-dextrin (Fe-Dex), polymyxin (PMX) either individually or in combination to induce cutaneous calciphylaxis. The clinical manifestation score, ratio of infiltrated lymphocytes, ratio of arteriole calcified nodules in skeletal muscles, serum antibody levels [anti-histidyl tRNA synthetase (Jo-1) and anti-melanoma differentiation-associated protein 5 (MDA5)] and serum cytokine levels [tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ)] were then detected. The results demonstrated that all five autoimmune groups displayed local cutaneous swelling and weakness, increased serum antibody and cytokine levels, and T lymphocyte infiltration in perimysial and perivascular sites. Moreover, pathological changes indicative of calciphylaxis were observed in the PMX and DHT + Fe-Dex + PMX. Among all groups, the rats in the PMX and DHT + Fe-Dex + PMX displayed characteristics most closely resembling those of DM pathogenesis in patients. In conclusion, membrane antigen immunization combined with toxin-induced calciphylaxis can be used as a DM model in rats. This model may be used for the development of effective drugs for DM treatment.

Highly Multiplexed Mass Cytometry Identifies the Immunophenotype in the Skin of Dermatomyositis

Dermatomyositis (DM) is a rare, systemic autoimmune disease that most frequently affects the skin, muscles, and lungs. The inflammatory infiltrate in the skin has not been fully characterized, and, in this study, we took a single-cell, unbiased approach using imaging mass cytometry. Substantial monocyte‒macrophage diversity was observed, with the CD14+ population correlating positively with Cutaneous Dermatomyositis Disease Area and Severity Index scores (P = 0.031). The T-cell compartment revealed CD4+ T, CD8+ T, and FOXP3+ T cells. Activated (CD69+) circulating memory T cells correlated positively with Cutaneous Dermatomyositis Disease Area and Severity Index scores (P = 0.0268). IFN-β protein was highly upregulated in the T-cell, macrophage, dendritic cell, and endothelial cell populations of DM skin. Myeloid dendritic cells expressed phosphorylated peroxisome proliferator‒activated receptor γ, phosphorylated IRF3, IL-4, and IL-31, and their quantity correlated with itch as measured in Skindex-29. Plasmacytoid dendritic cells colocalized with IFN-γ in addition to the known colocalization with IFN-β. Nuclear phosphorylated peroxisome proliferator‒activated receptor γ expression was found in the DM endothelium. Imaging mass cytometry allows us to characterize single cells in the immune cell population and identify upregulated cytokines and inflammatory pathways in DM. These findings have important implications for the development of future targeted therapies for DM.

Cytokines and inflammatory mediators as promising markers of polymyositis/dermatomyositis

PURPOSE OF REVIEW

Idiopathic inflammatory myopathies (IIMs), known also as myositis, represent challenging group of heterogeneous muscle disorders characterized by symmetric proximal muscle weakness and evidence of muscle inflammation. The purpose of this review is to provide important updates on cytokines and inflammatory mediators related to myositis.

RECENT FINDINGS

In the past 5 years, multiple studies brought a fresh insight into the pathogenesis of myositis by introducing new factors or further characterizing the role of the well established mediators in myositis. Among the mediators reviewed in this article, special attention was paid to interferons, C-X-C motif chemokine ligand 10, interleukin-18 and the IL23/Th17 axis. Some of the recent work has also focused on the nontraditional cytokines, such as adipokines, myokines, S100 proteins, High Mobility Group Box 1 or B-cell activating factor and on several anti-inflammatory mediators. Moreover, microRNAs and their potential to reflect the disease activity or to regulate the inflammatory processes in myositis have recently been subject of intensive investigation. Some of the above-mentioned mediators have been proposed as promising clinical biomarkers or therapeutic targets for myositis.

SUMMARY

Several recent studies contributed to a better understanding of the pathogenesis of myositis and highlighted the clinical significance of certain inflammatory mediators. Application of these new findings may help to develop innovative approaches for patients' phenotyping, disease activity monitoring and potentially novel therapies.

Serum levels of interleukins and S100A8/A9 correlate with clinical severity in patients with dermatomyositis-associated interstitial lung disease

Background

Dermatomyositis (DM) is a systemic autoimmune inflammatory disorder that affects primarily skin, muscle and lung, frequently associated with interstitial lung disease (ILD). The objective of this study is to investigate the association between serum cytokines and clinical severity in patients with DM-ILD.

Methods

Serum samples of 30 healthy controls, 14 DM patients without ILD and 40 DM patients with ILD were collected. Serum S100A8/A9 levels were analyzed by enzyme-linked immunosorbent assay (ELISA) and levels of interleukins were measured by cytometric beads array (CBA). Then we performed multivariate logistic regression analysis to determine factors independently associated with ILD development.

Results

Serum IL-4, IL-6 and S100A8/A9 levels were significantly higher in DM patients with ILD than those in healthy controls (p = 0.0013, 0.0017 and < 0.0001, respectively). Serum IL-10 level of patients was dramatically lower than that in controls (p = 0.0001). In DM patients, the levels were significantly higher in patients with A/SIP than in those with CIP (p = 0.0046, 0.0339 and 0.0133) or without ILD (p = 0.0165, 0.0370 and < 0.0001). IL-4 (r = 0.1171, p = 0.0040), IL-6 (r = 0.1174, p = 0.0040) and IL-10 (r = − 0.1829, p = 0.0003) were significantly correlated with S100A8/A9 in DM-ILD patients. S100A8/A9 was significantly correlated with high-resolution computed tomography (HRCT) (r = 0.1642, p = 0.0157) and lung function (DLCO%: r = − 0.2066, p = 0.0061, FVC%: r = − 0.2156, p = 0.0050). Moreover, logistic regression analysis revealed that S100A8/A9 levels were independently associated with ILD development in DM patients (p = 0.004).

Conclusions

Serum level of S100A8/A9 may be a valuable predictor for assessing the clinical severity of DM-ILD patients. Serum IL-4, IL-6 and IL-10 levels were highly correlated with S100A8/A9, so these cytokines may play a synergistic effect on the progression of DM-ILD.

Clinical trials and novel therapeutics in dermatomyositis

INTRODUCTION

Currently, there are no proven drugs that are FDA approved for the treatment of dermatomyositis (DM), even though multiple clinical trials are ongoing to evaluate safety and efficacy of novel therapeutics in DM. The purpose of this review is to highlight the biological plausibility, existing clinical evidence as well as completed and ongoing clinical trials for various drugs in pipeline for development for use in dermatomyositis.

AREAS COVERED

The drugs with the strongest evidence have been included in this review with a focus on the mechanism of their action pertaining to the disease process, clinical studies including completed and ongoing trials. With better understanding of the underlying pathophysiologic process, there are new molecular targets that have been identified that can be targeted by these novel drugs, predominantly biologic drugs.

EXPERT OPINION

There are various drugs being evaluated in phase II/III clinical trials that hold promise in DM. At the forefront of these are immunoglobulin, Lenabasum, and Abatacept for which phase III clinical trials are ongoing. In addition, promising clinical studies are ongoing or reported for KZR-616, anti-B cell therapy, anti-interferon drugs, and Repository Corticotrophin Injection (RCI).

A high level of serum neopterin is associated with rapidly progressive interstitial lung disease and reduced survival in dermatomyositis

Neopterin is primarily synthesized and released by activated macrophages/monocytes upon stimulation with interferon-γ and is considered as a marker for macrophage activation. This study aimed to analyze the serum levels of neopterin in patients with dermatomyositis (DM) in association with clinical manifestations, laboratory data and patient prognosis. One hundred and eighty-two consecutive DM patients and 30 healthy controls were retrospectively enrolled into the study. Serum levels of neopterin were significantly increased in DM patients compared to healthy controls (P < 0·001). High serum neopterin levels were associated with anti-melanoma differentiation-associated gene (MDA5) antibody, rapidly progressive interstitial lung disease (RP-ILD) and characteristic DM cutaneous involvement. Longitudinal assessment of serum samples revealed that the serum neopterin levels were closely correlated with disease severity (β = 30·24, P < 0·001). In addition, a significant increase in serum neopterin concentration of non-survivors was observed when compared to that of survivors (P < 0·001). Receiver operator characteristic curves showed that serum neopterin could distinguish non-survivors and survivors at an optimal cut-off level of 22·1 nmol/l with a sensitivity and specificity of 0·804 and 0·625, respectively (P < 0·001). Kaplan-Meier survival curves revealed that DM patients with serum neopterin > 22·1 nmol/l had a significantly higher mortality compared to the patient group with serum neopterin < 22·1 nmol/l (log-rank P < 0·001). Multivariate regression analysis identified high serum neopterin concentration to be an independent risk factor for poor prognosis in DM (adjusted hazard ratio = 4·619, 95% confidence interval = 2·092-10·195, P < 0·001). In conclusion, increased serum levels of neopterin were significantly associated with RP-ILD and reduced survival in DM patients, suggesting it as a promising biomarker in disease evaluation of DM.

Integrated therapy decreases the mortality of patients with polymyositis and dermatomyositis: A Taiwan-wide population-based retrospective study

ETHNOPHARMACOLOGICAL RELEVANCE

The issue of whether integrated treatment with conventional medicine (CM) and herbal medicine (HM) can reduce mortality in patients with polymyositis/dermatomyositis (PM/DM) had not been addressed.

AIM OF THE STUDY

In this study, we investigated the effect of integrated therapy on mortality in a retrospective PM/DM cohort in the Taiwan National Health Insurance Research Database (NHIRD).

MATERIALS AND METHODS

Patients with PM/DM were retrospectively enrolled from the PM/DM Registry of Catastrophic Illnesses cohort in the Taiwan NHIRD between 1997 and 2011. The patients were divided into an integrated medicine (IM) group that received CM and HM and a non-IM group that received CM alone. The Cox proportional hazards regression model and Kaplan-Meier method were used to evaluate the hazard ratio (HR) for mortality.

RESULTS

Three hundred and eighty-five of 2595 patients with newly diagnosed PM/DM had received IM and 99 had received non-IM. The adjusted HR for mortality was lower in the IM group than in the non-IM group (0.42, 95% confidence interval 0.26-0.68, p < 0.001). The adjusted HR for mortality was also lower in the IM group that had received CM plus HM than in the group that received CM alone (0.48, 95% confidence interval 0.28-0.84, p < 0.05). The core pattern of HM prescriptions integrated with methylprednisolone, methotrexate, azathioprine, or cyclophosphamide to decrease mortality included "San-Qi" (Panax notoginseng), "Bai-Ji" (Bletilla striata), "Chen-Pi" (Citrus reticulata), "Hou-Po" (Magnolia officinalis), and "Dan-Shan" (Salvia miltiorrhiza).

CONCLUSION

Integrated therapy has reduced mortality in patients with PM/DM in Taiwan. Further investigation of the clinical effects and pharmaceutical mechanism involved is needed.