scholarly journals The Immune System in Duchenne Muscular Dystrophy Pathogenesis

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1447
Author(s):  
Luana Tripodi ◽  
Chiara Villa ◽  
Davide Molinaro ◽  
Yvan Torrente ◽  
Andrea Farini
Keyword(s):  
Skeletal Muscle ◽  
T Cells ◽  
Immune System ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Point Of View ◽  
Central Tolerance ◽  
Immune System Activation ◽  
Killer T Cells

Growing evidence demonstrates the crosstalk between the immune system and the skeletal muscle in inflammatory muscle diseases and dystrophic conditions such as Duchenne Muscular Dystrophy (DMD), as well as during normal muscle regeneration. The rising of inflammation and the consequent activation of the immune system are hallmarks of DMD: several efforts identified the immune cells that invade skeletal muscle as CD4+ and CD8+ T cells, Tregs, macrophages, eosinophils and natural killer T cells. The severity of muscle injury and inflammation dictates the impairment of muscle regeneration and the successive replacement of myofibers with connective and adipose tissue. Since immune system activation was traditionally considered as a consequence of muscular wasting, we recently demonstrated a defect in central tolerance caused by thymus alteration and the presence of autoreactive T-lymphocytes in DMD. Although the study of innate and adaptive immune responses and their complex relationship in DMD attracted the interest of many researchers in the last years, the results are so far barely exhaustive and sometimes contradictory. In this review, we describe the most recent improvements in the knowledge of immune system involvement in DMD pathogenesis, leading to new opportunities from a clinical point-of-view.

Reparative dysfunction during muscle regeneration in Duchenne muscular dystrophy: therapeutic approaches to modulating the muscle environment and muscle stem cells

2019 ◽  
Author(s):  
◽  
Michael Everette Nance
Keyword(s):  
Skeletal Muscle ◽  
Stem Cells ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Genetic Mutation ◽  
Critical Determinant ◽  
Muscle Stem Cells ◽  
Dystrophin Protein

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Duchenne muscular dystrophy (DMD) is a lethal muscular dystrophy resulting from functional loss of the dystrophin protein, a critical sub-sarcolemmal protein involved in membrane stability. While reparative dysfunction is thought to be a critical determinant of disease progression in humans, regeneration is not significantly impaired in the murine muscular dystrophy (mdx) model. Furthermore, it is not well understood if reparative dysfunction is related to inherent defects in stem cells or chronic alterations in the muscle environment due to disease related remodeling. To address these observed discrepancies, we adapted a whole muscle transplant model to study the in vivo regeneration of intact pieces of skeletal muscle from normal and dystrophic dogs (cDMD), a physiological and clinically relevant model to humans. Regeneration in cDMD muscle grafts was significantly attenuated compared to normal and predisposed to the development of skeletal muscle tumors. We used an adeno-associated virus (AAV) expressing a micro-dystrophin protein to specifically rescue the muscle environment by preventing fiber damage while retaining dystrophin-null SCs. AAV.micro-dystrophin rescued the environment by improving fibrosis, stiffness, and fiber orientation, which significantly improved early muscle regeneration but not late regeneration (2 greater than and less than 4 months post-transplant) via enhancing muscle stem cells differentiation. We next developed Cre- and CRISPR-cas9 gene editing strategies to test the ability of AAV serotype 9 to transduce and treat the genetic mutation in muscle stem cells. We observed efficient SC transduction when used as a single vector expressing Cre. Dual-vector CRISPR-cas9 SC transduction was inefficient and likely related to the requirement for two vectors, promoter usage, and mechanistic differences between Cre-recombination and CRISPR genome editing.

scholarly journals The PKA-p38MAPK-NFAT5-Organic Osmolytes Pathway in Duchenne Muscular Dystrophy: From Essential Player in Osmotic Homeostasis, Inflammation and Skeletal Muscle Regeneration to Therapeutic Target

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 350
Author(s):  
Sandrine Herbelet ◽  
Caroline Merckx ◽  
Boel De Paepe
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Protein Kinase ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Janus Kinase ◽  
Skeletal Muscle Regeneration ◽  
Organic Osmolytes ◽  
Nuclear Factor ◽  
Osmotic Homeostasis

In Duchenne muscular dystrophy (DMD), the absence of dystrophin from the dystrophin-associated protein complex (DAPC) causes muscle membrane instability, which leads to myofiber necrosis, hampered regeneration, and chronic inflammation. The resulting disabled DAPC-associated cellular pathways have been described both at the molecular and the therapeutical level, with the Toll-like receptor nuclear factor kappa-light-chain-enhancer of activated B cells pathway (NF-ƘB), Janus kinase/signal transducer and activator of transcription proteins, and the transforming growth factor-β pathways receiving the most attention. In this review, we specifically focus on the protein kinase A/ mitogen-activated protein kinase/nuclear factor of activated T-cells 5/organic osmolytes (PKA-p38MAPK-NFAT5-organic osmolytes) pathway. This pathway plays an important role in osmotic homeostasis essential to normal cell physiology via its regulation of the influx/efflux of organic osmolytes. Besides, NFAT5 plays an essential role in cell survival under hyperosmolar conditions, in skeletal muscle regeneration, and in tissue inflammation, closely interacting with the master regulator of inflammation NF-ƘB. We describe the involvement of the PKA-p38MAPK-NFAT5-organic osmolytes pathway in DMD pathophysiology and provide a clear overview of which therapeutic molecules could be of potential benefit to DMD patients. We conclude that modulation of the PKA-p38MAPK-NFAT5-organic osmolytes pathway could be developed as supportive treatment for DMD in conjunction with genetic therapy.

scholarly journals In situ localisation of single-stranded DNA breaks in nuclei of a subpopulation of cells within regenerating skeletal muscle of the dystrophic mdx mouse

1992 ◽  
Vol 102 (3) ◽  
pp. 653-662 ◽  
Author(s):  
G.R. Coulton ◽  
B. Rogers ◽  
P. Strutt ◽  
M.J. Skynner ◽  
D.J. Watt
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Dna Polymerase ◽  
Muscle Regeneration ◽  
Regenerative Process ◽  
Muscle Fibres ◽  
Dna Breaks ◽  
Expression Of Genes ◽  
Muscle Lesions

Degeneration of muscle fibres during the early stages of Duchenne Muscular Dystrophy (DMD) is accompanied by muscle fibre regeneration where cell division and myoblast fusion to form multinucleate myotubes within the lesions appear to recapitulate the events of normal muscle development. The mechanisms that govern the expression of genes regulating differentiation of myoblasts in regenerating skeletal muscle are of great interest for the development of future therapies designed to stimulate muscle regeneration. We show here that single-stranded breaks in DNA are localised in nuclei, using an exogenously applied medium containing labelled deoxynucleotides and the Klenow fragment of DNA polymerase I. The nuclei of a sub-population of cells lying in the inflammatory infiltrate of lesions in the skeletal muscle of the muscular dystrophic mouse (mdx), a genetic homologue of DMD, were labelled in this fashion. By contrast, labelled cells were completely absent from the muscles of normal non-myopathic animals (C57BL/10) and non-lesioned areas of mdx muscles. Cells expressing the muscle-specific regulatory gene, myogenin, were also found within mononucleate cells and myotubes within similar mdx muscle lesions. While we cannot yet say that the cells labelled by the DNA polymerase reaction are in fact differentiating, they were found only in significant numbers within mdx muscle lesions where new muscle fibres appear, providing strong circumstantial evidence that they are intimately associated with the regenerative process. Using a range of nucleases and different DNA polymerases, we show that the DNA polymerase-labelling reaction observed was DNA-dependent and most probably due to infilling of naturally occurring single-stranded gaps in DNA. Since the regenerative process in human Duchenne Muscular Dystrophy is apparently less effective than that seen in mdx mice, continued study of single-stranded DNA breaks may help to elucidate further the mechanisms controlling the expression of genes that characterise the myogenic process during skeletal muscle regeneration. Such findings might be applied in the development of future therapies designed to stimulate muscle regeneration in human dystrophies.

scholarly journals Cellular senescence-mediated exacerbation of Duchenne muscular dystrophy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hidetoshi Sugihara ◽  
Naomi Teramoto ◽  
Katsuyuki Nakamura ◽  
Takanori Shiga ◽  
Taku Shirakawa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Strength ◽  
Progenitor Cells ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Mesenchymal Progenitor Cells

Abstract Duchenne muscular dystrophy (DMD) is a progressive disease characterised by chronic muscle degeneration and inflammation. Our previously established DMD model rats (DMD rats) have a more severe disease phenotype than the broadly used mouse model. We aimed to investigate the role of senescence in DMD using DMD rats and patients. Senescence was induced in satellite cells and mesenchymal progenitor cells, owing to the increased expression of CDKN2A, p16- and p19-encoding gene. Genetic ablation of p16 in DMD rats dramatically restored body weight and muscle strength. Histological analysis showed a reduction of fibrotic and adipose tissues invading skeletal muscle, with increased muscle regeneration. Senolytic drug ABT263 prevented loss of body weight and muscle strength, and increased muscle regeneration in rats even at 8 months—the late stage of DMD. Moreover, senescence markers were highly expressed in the skeletal muscle of DMD patients. In situ hybridization of CDKN2A confirmed the expression of it in satellite cells and mesenchymal progenitor cells in patients with DMD. Collectively, these data provide new insights into the integral role of senescence in DMD progression.

scholarly journals microRNA-206 promotes skeletal muscle regeneration and delays progression of Duchenne muscular dystrophy in mice

2012 ◽  
Vol 122 (6) ◽  
pp. 2054-2065 ◽  
Author(s):  
Ning Liu ◽  
Andrew H. Williams ◽  
Johanna M. Maxeiner ◽  
Svetlana Bezprozvannaya ◽  
John M. Shelton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Skeletal Muscle Regeneration

Reduced Hedgehog signalling in Duchenne muscular dystrophy impairs muscle regeneration and function

2017 ◽  
Vol 27 ◽  
pp. S13
Author(s):  
S. Devenport ◽  
C.M. Penton ◽  
N. Salgado ◽  
H. Wang ◽  
K. Flanigan ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Hedgehog Signalling ◽  
And Function

scholarly journals MiRNAs and Muscle Regeneration: Therapeutic Targets in Duchenne Muscular Dystrophy

2021 ◽  
Vol 22 (8) ◽  
pp. 4236
Author(s):  
Amelia Eva Aránega ◽  
Estefanía Lozano-Velasco ◽  
Lara Rodriguez-Outeiriño ◽  
Felicitas Ramírez de Acuña ◽  
Diego Franco ◽  
...  
Keyword(s):  
Stem Cell ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Regeneration ◽  
Transcriptional Control ◽  
Neuromuscular Disorders ◽  
Critical Role ◽  
Gene Replacement ◽  
Control Of Gene Expression ◽  
Muscle Disorders

microRNAs (miRNAs) are small non-coding RNAs required for the post-transcriptional control of gene expression. MicroRNAs play a critical role in modulating muscle regeneration and stem cell behavior. Muscle regeneration is affected in muscular dystrophies, and a critical point for the development of effective strategies for treating muscle disorders is optimizing approaches to target muscle stem cells in order to increase the ability to regenerate lost tissue. Within this framework, miRNAs are emerging as implicated in muscle stem cell response in neuromuscular disorders and new methodologies to regulate the expression of key microRNAs are coming up. In this review, we summarize recent advances highlighting the potential of miRNAs to be used in conjunction with gene replacement therapies, in order to improve muscle regeneration in the context of Duchenne Muscular Dystrophy (DMD).

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

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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