Cytokines and Chemokines as Regulators of Skeletal Muscle Inflammation: Presenting the Case of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy is a severe inherited muscle disease that affects 1 in 3500 boys worldwide. Infiltration of skeletal muscle by inflammatory cells is an important facet of disease pathophysiology and is strongly associated with disease severity in the individual patient. In the chronic inflammation that characterizes Duchenne muscle, cytokines and chemokines are considered essential activators and recruiters of inflammatory cells. In addition, they provide potential beneficiary effects on muscle fiber damage control and tissue regeneration. In this review, current knowledge of cytokine and chemokine expression in Duchenne muscular dystrophy and its relevant animal disease models is listed, and implications for future therapeutic avenues are discussed.

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Multiomics Analysis of the mdx/mTR Mouse Model of Duchenne Muscular Dystrophy

10.1101/589424 ◽

2019 ◽

Cited By ~ 1

Author(s):

Douglas W Van Pelt ◽

Yalda A Kharaz ◽

Dylan C Sarver ◽

Logan R Eckhardt ◽

Justin T Dzierzawski ◽

...

Keyword(s):

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Muscle Metabolism ◽

Muscle Disease ◽

Protein Abundance ◽

Pathological Changes ◽

Hindlimb Muscles ◽

Dystrophin Protein ◽

Insight Into

AbstractDuchenne muscular dystrophy (DMD) is a progressive neuromuscular disease characterized by extensive muscle weakness. Patients with DMD lack a functional dystrophin protein, which transmits force and organizes the cytoskeleton of skeletal muscle. Multiomic studies evaluate combined changes in the transcriptome, proteome, and metabolome, and have been proposed as a way to obtain novel insight about disease processes from preclinical models. We therefore sought to use this approach to study pathological changes in dystrophic muscles. We evaluated hindlimb muscles of male mdx/mTR mice, which lack a functional dystrophin protein and have deficits in satellite cell abundance and proliferative capacity. Wild type (WT) C57BL/6J mice served as controls. Muscle fiber contractility was measured, along with changes in the transcriptome using RNA sequencing, and in the proteome, metabolome, and lipidome using mass spectroscopy. While mdx/mTR mice displayed gross pathological changes and continued cycles of degeneration and regeneration, we found no differences in fiber contractility between strains. However, there were numerous changes in the transcriptome and proteome related to protein balance, contractile elements, extracellular matrix, and metabolism. There was only a 53% agreement in fold change data between the proteome and transcriptome, highlighting the need to study protein abundance along with gene expression measures. Numerous changes in markers of skeletal muscle metabolism were observed, with dystrophic muscles exhibiting elevated glycolytic metabolites. These findings highlight the utility of multiomics in studying muscle disease, and provide additional insight into the pathological changes in dystrophic muscles that might help to guide evidence-based exercise prescription in DMD patients.

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Chloroquine Decreases Cardiomyocyte Autophagy and Improves Cardiac Function in a Mouse Model of Duchenne Muscular Dystrophy

10.21203/rs.3.rs-149383/v1 ◽

2021 ◽

Author(s):

Takaya Hirata ◽

Shiro Baba ◽

Kentaro Akagi ◽

Daisuke Yoshinaga ◽

Katsutsugu Umeda ◽

...

Keyword(s):

Heart Failure ◽

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Left Ventricular ◽

Muscle Disease ◽

Therapeutic Modality ◽

Cardiomyocyte Autophagy ◽

And Function ◽

Ventricle Size

Abstract Background: Duchenne muscular dystrophy (DMD), a severe degenerative skeletal and cardiac muscle disease, has a poor prognosis, and no curative treatments are available. Because autophagy has been reported to contribute to skeletal muscle degeneration, therapies targeting autophagy are expected to improve skeletal muscle hypofunction. However, the role of this regulatory mechanism has not been evaluated clearly in DMD cardiomyocytes. Methods: In the present study, we demonstrated that autophagy was enhanced in the cardiomyocytes of mdx mice, a model of DMD, and that increased autophagy contributed to the development of cardiomyopathy in this context. Results: As assessed by GFP-mRFP-LC3 transfection, autophagosomes were more abundant in cardiomyocytes of mdx mice compared with control wild-type (WT) mice. The number of autophagosomes was significantly enhanced by isoproterenol-induced cardiac stress (4 weeks) in cardiomyocytes of mdx but not WT mice. Simultaneously, isoproterenol increased cardiomyocyte fibrosis in mdx but not WT mice. Administration of chloroquine, an autophagy inhibitor, significantly decreased cardiomyocyte autophagy and fibrosis in mdx mice, even after isoproterenol treatment. Left ventricle size and function were evaluated by echocardiography. Left ventricular contraction was decreased in mdx mice after isoproterenol treatment compared with control mice, which was alleviated by chloroquine administration.Conclusions: These findings suggested that heart failure of DMD could be associated with autophagy. Therefore, autophagy inhibitors, such as chloroquine, are a potential therapeutic modality for heart failure in DMD patients.

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Understanding the Process of Fibrosis in Duchenne Muscular Dystrophy

BioMed Research International ◽

10.1155/2014/965631 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 89

Author(s):

Yacine Kharraz ◽

Joana Guerra ◽

Patrizia Pessina ◽

Antonio L. Serrano ◽

Pura Muñoz-Cánoves

Keyword(s):

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Inflammatory Cells ◽

Dystrophin Gene ◽

New Developments ◽

Muscle Stem Cells ◽

Muscle Fibrosis ◽

Tissue Healing ◽

And Function

Fibrosis is the aberrant deposition of extracellular matrix (ECM) components during tissue healing leading to loss of its architecture and function. Fibrotic diseases are often associated with chronic pathologies and occur in a large variety of vital organs and tissues, including skeletal muscle. In human muscle, fibrosis is most readily associated with the severe muscle wasting disorder Duchenne muscular dystrophy (DMD), caused by loss of dystrophin gene function. In DMD, skeletal muscle degenerates and is infiltrated by inflammatory cells and the functions of the muscle stem cells (satellite cells) become impeded and fibrogenic cells hyperproliferate and are overactivated, leading to the substitution of skeletal muscle with nonfunctional fibrotic tissue. Here, we review new developments in our understanding of the mechanisms leading to fibrosis in DMD and several recent advances towards reverting it, as potential treatments to attenuate disease progression.

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Faculty Opinions recommendation of microRNA-206 promotes skeletal muscle regeneration and delays progression of Duchenne muscular dystrophy in mice.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717397850.793153110 ◽

2012 ◽

Author(s):

Michael Rudnicki ◽

Alessandra Pasut

Keyword(s):

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Muscle Regeneration ◽

Skeletal Muscle Regeneration

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Genotype characterization and delayed loss of ambulation by glucocorticoids in a large cohort of patients with Duchenne muscular dystrophy

Orphanet Journal of Rare Diseases ◽

10.1186/s13023-021-01837-x ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Shu Zhang ◽

◽

Dongdong Qin ◽

Liwen Wu ◽

Man Li ◽

...

Keyword(s):

Clinical Trials ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Hazard Ratio ◽

Large Cohort ◽

Muscle Disease ◽

Clinical Progression ◽

Large Deletions ◽

The Mean ◽

Lower Hazard

Abstract Background Duchenne muscular dystrophy (DMD) is the most common genetic muscle disease in human. We aimed to describe the genotype distribution in a large cohort of Chinese DMD patients and their delayed loss of ambulation by glucocorticoid (GC) treatments. This is to facilitate protocol designs and outcome measures for the emerging DMD clinical trials. Results A total of 1163 patients with DMD were recruited and genotyped. Genotype variations were categorized as large deletions, large duplications, and small mutations. Large deletions were further analyzed for those amenable to exon-skipping therapies. Participants aged 5 years or older were grouped into GC-treated and GC-naïve groups. Clinical progression among different genotypes and their responses to GC treatments were measured by age at loss of ambulation (LOA). Among the mutation genotypes, large deletions, large duplications, and small mutations accounted for 68.79%, 7.14%, and 24.07%, respectively. The mean age at diagnosis was 4.59 years; the median ages at LOA for the GC-naïve, prednisone/prednisolone-treated, and deflazacort-treated groups were 10.23, 12.02, and 13.95 years, respectively. The “deletion amenable to skipping exon 44” subgroup and the nonsense-mutation subgroup had older ages at LOA than the “other deletions” subgroup. Subgroups were further analyzed by both genotypes and GC status. All genotypes showed significant beneficial responses to GC treatment. Deletions amenable to skipping exon 44 showed a lower hazard ratio (0.155). The mean age at death was 18.57 years in this DMD group. Conclusion Genotype variation influences clinical progression in certain DMD groups. Beneficial responses to GC treatment were observed among all DMD genotypes. Compared with other genotypes, deletions amenable to skipping exon 44 had a lower hazard ratio, which may indicate a stronger protective effect of GC treatments on this subgroup. These data are valuable for designing future clinical trials, as clinical outcomes may be influenced by the genotypes.

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Wearable robotic exoskeletons: A socio-philosophical perspective on Duchenne muscular dystrophy research

Paladyn Journal of Behavioral Robotics ◽

10.1515/pjbr-2020-0027 ◽

2020 ◽

Vol 11 (1) ◽

pp. 404-413

Author(s):

Alexandra Kapeller ◽

Michael H. Nagenborg ◽

Kostas Nizamis

Keyword(s):

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Disability Studies ◽

Philosophy Of Technology ◽

Research Projects ◽

Philosophical Perspective ◽

Individual Model ◽

Engineering Sciences ◽

The Social ◽

The Individual

AbstractRecently, several research projects in the Netherlands have focused on the development of wearable robotic exoskeletons (WREs) for individuals with Duchenne muscular dystrophy (DMD). Such research on WREs is often treated solely within the disciplines of biomedical and mechanical engineering, overlooking insights from disability studies and philosophy of technology. We argue that mainly two such insights should receive attention: the problematization of the ableism connected to the individual model of disability and the stigmatization by assistive technology. While disability studies have largely rejected the individual model of disability, the engineering sciences seem to still locate disability in an individual’s body, not questioning their own problematization of disability. Additionally, philosophy of technology has argued that technologies are not neutral instruments but shape users’ actions and perceptions. The design of WREs may convey a message about the understanding of disability, which can be comprehended as a challenge and an opportunity: stigmatization needs to be avoided and positive views on disability can be evoked. This article aims to highlight the benefits of considering these socio-philosophical perspectives by examining the case of WREs for people with DMD and proposing design principles for WREs. These principles may enhance acceptability of WREs, not only by individuals with DMD but also by other users, and help engineers to better place their work in the social context.

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Autophagy in the heart is enhanced and independent of disease progression in mus musculus dystrophinopathy models

JRSM Cardiovascular Disease ◽

10.1177/2048004019879581 ◽

2019 ◽

Vol 8 ◽

pp. 204800401987958

Author(s):

HR Spaulding ◽

C Ballmann ◽

JC Quindry ◽

MB Hudson ◽

JT Selsby

Keyword(s):

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Disease Progression ◽

Gene Mutations ◽

Dystrophin Gene ◽

Mdx Mice ◽

Dystrophin Deficiency ◽

Muscle Wasting Disease ◽

Dystrophin Protein

Background Duchenne muscular dystrophy is a muscle wasting disease caused by dystrophin gene mutations resulting in dysfunctional dystrophin protein. Autophagy, a proteolytic process, is impaired in dystrophic skeletal muscle though little is known about the effect of dystrophin deficiency on autophagy in cardiac muscle. We hypothesized that with disease progression autophagy would become increasingly dysfunctional based upon indirect autophagic markers. Methods Markers of autophagy were measured by western blot in 7-week-old and 17-month-old control (C57) and dystrophic (mdx) hearts. Results Counter to our hypothesis, markers of autophagy were similar between groups. Given these surprising results, two independent experiments were conducted using 14-month-old mdx mice or 10-month-old mdx/Utrn± mice, a more severe model of Duchenne muscular dystrophy. Data from these animals suggest increased autophagosome degradation. Conclusion Together these data suggest that autophagy is not impaired in the dystrophic myocardium as it is in dystrophic skeletal muscle and that disease progression and related injury is independent of autophagic dysfunction.

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The KATP channel Kir6.2 subunit content is higher in glycolytic than oxidative skeletal muscle fibers

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00663.2010 ◽

2011 ◽

Vol 301 (4) ◽

pp. R916-R925 ◽

Cited By ~ 18

Author(s):

Krystyna Banas ◽

Charlene Clow ◽

Bernard J. Jasmin ◽

Jean-Marc Renaud

Keyword(s):

Skeletal Muscle ◽

Cross Sections ◽

Fiber Type ◽

Energy Levels ◽

Muscle Fibers ◽

Metabolic Stress ◽

Oxidative Capacity ◽

Fiber Types ◽

Fiber Damage ◽

The Individual

It has long been suggested that in skeletal muscle, the ATP-sensitive K+ channel (KATP) channel is important in protecting energy levels and that abolishing its activity causes fiber damage and severely impairs function. The responses to a lack of KATP channel activity vary between muscles and fibers, with the severity of the impairment being the highest in the most glycolytic muscle fibers. Furthermore, glycolytic muscle fibers are also expected to face metabolic stress more often than oxidative ones. The objective of this study was to determine whether the t-tubular KATP channel content differs between muscles and fiber types. KATP channel content was estimated using a semiquantitative immunofluorescence approach by staining cross sections from soleus, extensor digitorum longus (EDL), and flexor digitorum brevis (FDB) muscles with anti-Kir6.2 antibody. Fiber types were determined using serial cross sections stained with specific antimyosin I, IIA, IIB, and IIX antibodies. Changes in Kir6.2 content were compared with changes in CaV1.1 content, as this Ca2+ channel is responsible for triggering Ca2+ release from sarcoplasmic reticulum. The Kir6.2 content was the lowest in the oxidative soleus and the highest in the glycolytic EDL and FDB. At the individual fiber level, the Kir6.2 content within a muscle was in the order of type IIB > IIX > IIA ≥ I. Interestingly, the Kir6.2 content for a given fiber type was significantly different between soleus, EDL, and FDB, and highest in FDB. Correlations of relative fluorescence intensities from the Kir6.2 and CaV1.1 antibodies were significant for all three muscles. However, the variability in content between the three muscles or individual fibers was much greater for Kir6.2 than for CaV1.1. It is suggested that the t-tubular KATP channel content increases as the glycolytic capacity increases and as the oxidative capacity decreases and that the expression of KATP channels may be linked to how often muscles/fibers face metabolic stress.

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