The dystrophin-deficient (mdx) mouse remains the most commonly used model for Duchenne muscular dystrophy (DMD). Mdx mice show a predominantly covert cardiomyopathy, the hallmark of which is fibrosis. We compared mdx and normal mice at six ages (3, 6, 9, 12, 15, and 18 months) using in vivo assessment of cardiac function, selective collagen staining, and measures of TGF-β mRNA, Evans blue dye infiltration, macrophage infiltration, and aortic wall thickness. Clear temporal progression was demonstrated, including early fragility of cardiomyocyte membranes, which has an unrelated impact on cardiac function but is associated with macrophage infiltration and fibrosis. Aortic wall thickness is less in older mdx mice. Mdx mice display impaired responses to inotropic challenge from a young age; this is indicative of altered adrenoreceptor function. We draw attention to the paradox of ongoing fibrosis in mdx hearts without a strong molecular signature (in the form of TGF-β mRNA expression).
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http://dx.doi.org/10.1002/mus.21716 | DOI Listing |
Muscle Nerve
January 2025
Department of Anatomy, Federal University of Alfenas (UNIFAL-MG), Alfenas, Brazil.
Introduction/aims: Duchenne muscular dystrophy (DMD) is caused by pathogenic variants in the DMD gene, making muscle fibers susceptible to contraction-induced membrane damage. Given the potential beneficial action of cannabidiol (CBD), we evaluated the in vitro effect of full-spectrum CBD oil on the viability of dystrophic muscle fibers and the in vivo effect on myopathy of the mdx mouse, a DMD model.
Methods: In vitro, dystrophic cells from the mdx mouse were treated with full-spectrum CBD oil and assessed with cell viability and cytotoxic analyses.
Am J Pathol
January 2025
Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095-1606; Molecular, Cellular & Integrative Physiology Program, University of California, Los Angeles, CA 90095-1606; Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA 90095. Electronic address:
Duchenne muscular dystrophy (DMD) is a lethal, muscle-wasting, genetic disease that is greatly amplified by an immune response to the diseased muscles. The mdx mouse model of DMD was used to test whether the pathology can be reduced by treatments with a CTLA4-Ig fusion protein that blocks costimulatory signals required for activation of T-cells. CTLA4-Ig treatments reduced mdx sarcolemma lesions and reduced the numbers of activated T-cells, macrophages and antigen presenting cells in mdx muscle and reduced macrophage invasion into muscle fibers.
View Article and Find Full Text PDFSkelet Muscle
January 2025
Department of Anesthesia and Critical Care, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Background: Duchenne muscular dystrophy (DMD) is a prevalent, fatal degenerative muscle disease with no effective treatments. Mdx mouse model of DMD exhibits impaired muscle performance, oxidative stress, and dysfunctional autophagy. Although antioxidant treatments may improve the mdx phenotype, the precise molecular mechanisms remain unclear.
View Article and Find Full Text PDFbioRxiv
January 2025
Institute of Muscle Biology and Cachexia, University of Houston College of Pharmacy, Houston, TX, USA.
Skeletal muscle regeneration in adults is predominantly driven by satellite cells. Loss of satellite cell pool and function leads to skeletal muscle wasting in many conditions and disease states. Here, we demonstrate that the levels of fibroblast growth factor-inducible 14 (Fn14) are increased in satellite cells after muscle injury.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Life Science and Public Health, Università Cattolica del Sacro Cuore, Rome, Italy.
Inefficient targeting of muscle stem cells (MuSCs), also called satellite cells, represents a major bottleneck of current therapeutic strategies for muscular dystrophies, as it precludes the possibility of promoting compensatory regeneration. Here we describe a muscle-targeting delivery platform, based on gold nanoparticles, that enables the release of therapeutic oligonucleotides into MuSCs. We demonstrate that AuNPs conjugation to an aptamer against α7/β1 integrin dimers directs either local or systemic delivery of microRNA-206 to MuSCs, thereby promoting muscle regeneration and improving muscle functionality, in a mouse model of Duchenne Muscular Dystrophy.
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