Effect of Duchenne muscular dystrophy on enzymes of energy metabolism in individual muscle fibers

Metabolism ◽  
1987 ◽  
Vol 36 (8) ◽  
pp. 761-767 ◽  
Author(s):  
Maggie M.-Y. Chi ◽  
Carol S. Hintz ◽  
Deidre McKee ◽  
Steven Felder ◽  
Natasha Grant ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Energy Metabolism ◽  
Muscular Dystrophy ◽  
Muscle Fibers ◽  
Individual Muscle ◽  
Enzymes Of Energy Metabolism

scholarly journals In vivo genome editing in mouse restores dystrophin expression in Duchenne muscular dystrophy patient muscle fibers

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Menglong Chen ◽  
Hui Shi ◽  
Shixue Gou ◽  
Xiaomin Wang ◽  
Lei Li ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Genome Editing ◽  
Large Scale ◽  
Gene Editing ◽  
High Efficiency ◽  
Muscle Fibers ◽  
Muscle Cells

Abstract Background Mutations in the DMD gene encoding dystrophin—a critical structural element in muscle cells—cause Duchenne muscular dystrophy (DMD), which is the most common fatal genetic disease. Clustered regularly interspaced short palindromic repeat (CRISPR)-mediated gene editing is a promising strategy for permanently curing DMD. Methods In this study, we developed a novel strategy for reframing DMD mutations via CRISPR-mediated large-scale excision of exons 46–54. We compared this approach with other DMD rescue strategies by using DMD patient-derived primary muscle-derived stem cells (DMD-MDSCs). Furthermore, a patient-derived xenograft (PDX) DMD mouse model was established by transplanting DMD-MDSCs into immunodeficient mice. CRISPR gene editing components were intramuscularly delivered into the mouse model by adeno-associated virus vectors. Results Results demonstrated that the large-scale excision of mutant DMD exons showed high efficiency in restoring dystrophin protein expression. We also confirmed that CRISPR from Prevotella and Francisella 1(Cas12a)-mediated genome editing could correct DMD mutation with the same efficiency as CRISPR-associated protein 9 (Cas9). In addition, more than 10% human DMD muscle fibers expressed dystrophin in the PDX DMD mouse model after treated by the large-scale excision strategies. The restored dystrophin in vivo was functional as demonstrated by the expression of the dystrophin glycoprotein complex member β-dystroglycan. Conclusions We demonstrated that the clinically relevant CRISPR/Cas9 could restore dystrophin in human muscle cells in vivo in the PDX DMD mouse model. This study demonstrated an approach for the application of gene therapy to other genetic diseases.

scholarly journals The microRNA, miR-133b, functions to slow Duchenne muscular dystrophy pathogenesis

2020 ◽  
Author(s):  
Thomas Taetzsch ◽  
Dillon Shapiro ◽  
Randa Eldosougi ◽  
Tracey Myers ◽  
Robert Settlage ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Skeletal Muscles ◽  
Tibialis Anterior Muscle ◽  
Muscle Fibers ◽  
Progressive Degeneration ◽  
Protein Encoding ◽  
Small Muscle ◽  
Encoding Genes

AbstractDuchenne muscular dystrophy (DMD) is characterized by progressive degeneration of skeletal muscles. To date, there are no treatments available to slow or prevent the disease. Hence, it remains essential to identify molecular factors that promote muscle biogenesis since they could serve as therapeutic targets for treating DMD. While the muscle enriched microRNA, miR-133b, has been implicated in the biogenesis of muscle fibers, its role in DMD remains unknown. To assess the role of miR-133b in DMD-affected skeletal muscles, we genetically ablated miR-133b in the mdx mouse model of DMD. In the absence of miR-133b, the tibialis anterior muscle of juvenile and adult mdx mice is populated by small muscle fibers with centralized nuclei, exhibits increased fibrosis, and thickened interstitial space. Additional analysis revealed that loss of miR-133b exacerbates DMD-pathogenesis partly by altering the number of satellite cells and levels of protein-encoding genes, including previously identified miR-133b targets as well as genes involved in cell proliferation and fibrosis. Altogether, our data demonstrate that skeletal muscles utilize miR-133b to mitigate the deleterious effects of DMD.

scholarly journals Duchenne and Becker Muscular Dystrophies: A Review of Animal Models, Clinical End Points, and Biomarker Quantification

2017 ◽  
Vol 45 (7) ◽  
pp. 961-976 ◽  
Author(s):  
Kristin Wilson ◽  
Crystal Faelan ◽  
Janet C. Patterson-Kane ◽  
Daniel G. Rudmann ◽  
Steven A. Moore ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Animal Models ◽  
Protein Expression ◽  
Neuromuscular Disorders ◽  
Muscle Fibers ◽  
Becker Muscular Dystrophy ◽  
Therapeutic Interventions ◽  
Fluorescent Intensity ◽  
Individual Muscle ◽  
Automated Method

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are neuromuscular disorders that primarily affect boys due to an X-linked mutation in the DMD gene, resulting in reduced to near absence of dystrophin or expression of truncated forms of dystrophin. Some newer therapeutic interventions aim to increase sarcolemmal dystrophin expression, and accurate dystrophin quantification is critical for demonstrating pharmacodynamic relationships in preclinical studies and clinical trials. Current challenges with measuring dystrophin include the variation in protein expression within individual muscle fibers and across whole muscle samples, the presence of preexisting dystrophin-positive revertant fibers, and trace amounts of residual dystrophin. Immunofluorescence quantification of dystrophin can overcome many of these challenges, but manual quantification of protein expression may be complicated by variations in the collection of images, reproducible scoring of fluorescent intensity, and bias introduced by manual scoring of typically only a few high-power fields. This review highlights the pathology of DMD and BMD, discusses animal models of DMD and BMD, and describes dystrophin biomarker quantitation in DMD and BMD, with several image analysis approaches, including a new automated method that evaluates protein expression of individual muscle fibers.

Abstract 478: Connexin-43 Reduction Rescues Cardiac and Skeletal Muscle Pathology in a Novel Mouse Model of Duchenne Muscular Dystrophy Symptomatic Carriers

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Julie Nouet ◽  
Eric Himelman ◽  
Diego Fraidenraich
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Muscle Fiber ◽  
Connexin 43 ◽  
Muscle Fibers ◽  
Skeletal Muscle Fiber ◽  
Muscle Pathology ◽  
Female Carriers

Duchenne muscular dystrophy (DMD) and its associated cardiomyopathy manifest in 8-10% of all female carriers however research remains male-centric. Although underrepresented, symptomatic females face the risk of cardiac, respiratory, and skeletal muscle problems. Basic research and clinical trials exclude female carriers therefore developments in treatment expose females to unknown safety and efficacy issues. The bottleneck is largely due to the absence of a faithful mouse model. To generate a mouse model, we injected mdx embryonic stem cells (ESCs) into wild-type (WT) blastocysts ( mdx /WT chimera). The cardiac and skeletal muscle phenotype recapitulates the same generated as a consequence of x-inactivation in human manifesting female patients. In the heart, mdx /WT chimeras develop fibrotic cardiomyopathy. In the skeletal muscle, we found evidence of fibrosis, inflammation and muscle weakness. We found that Connexin-43 (Cx43), the primary gap junctional protein in the heart, was pathologically enhanced and remodeled in mdx /WT chimeras. Cx43 was also enhanced in the dystrophic skeletal muscle. Genetic reduction of Cx43-copy number protected mdx /WT chimeras from cardiac and skeletal muscle fiber damage. The latter result was unexpected because Cx43 is not expressed in mature muscle fibers. Upon further investigation, Cx43 was localized to the mononuclear cells invading the interstitial space between dystrophic skeletal muscle fibers. Pathologically enhanced activity of Cx43 in mdx FACS-macrophages was observed via ethidium bromide uptake and the Cx43 hemichannel peptide mimetic, Gap19, inhibited Cx43 function in a dose-dependent manner. Because an excess of Cx43 has been associated with cell death, we believe that Cx43 reduction in invading mdx macrophages benefits the skeletal muscle of understudied DMD carriers, perhaps by a paracrine mechanism involving macrophage-skeletal muscle fiber communication.

scholarly journals Sarcoplasmic reticulum Ca2+ permeation explored from the lumen side in mdx muscle fibers under voltage control

2012 ◽  
Vol 139 (3) ◽  
pp. 209-218 ◽  
Author(s):  
Gaëlle Robin ◽  
Christine Berthier ◽  
Bruno Allard
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Sarcoplasmic Reticulum ◽  
Muscular Dystrophy ◽  
Action Potentials ◽  
Muscle Fibers ◽  
Cyclopiazonic Acid ◽  
Recovery Phase ◽  
Resting Potential ◽  
Mdx Mice

Under resting conditions, external Ca2+ is known to enter skeletal muscle cells, whereas Ca2+ stored in the sarcoplasmic reticulum (SR) leaks into the cytosol. The nature of the pathways involved in the sarcolemmal Ca2+ entry and in the SR Ca2+ leak is still a matter of debate, but several lines of evidence suggest that these Ca2+ fluxes are up-regulated in Duchenne muscular dystrophy. We investigated here SR calcium permeation at resting potential and in response to depolarization in voltage-controlled skeletal muscle fibers from control and mdx mice, the mouse model of Duchenne muscular dystrophy. Using the cytosolic Ca2+ dye Fura2, we first demonstrated that the rate of Ca2+ increase in response to cyclopiazonic acid (CPA)–induced inhibition of SR Ca2+-ATPases at resting potential was significantly higher in mdx fibers, which suggests an elevated SR Ca2+ leak. However, removal of external Ca2+ reduced the rate of CPA-induced Ca2+ increase in mdx and increased it in control fibers, which indicates an up-regulation of sarcolemmal Ca2+ influx in mdx fibers. Fibers were then loaded with the low-affinity Ca2+ dye Fluo5N-AM to measure intraluminal SR Ca2+ changes. Trains of action potentials, chloro-m-cresol, and depolarization pulses evoked transient Fluo5N fluorescence decreases, and recovery of voltage-induced Fluo5N fluorescence changes were inhibited by CPA, demonstrating that Fluo5N actually reports intraluminal SR Ca2+ changes. Voltage dependence and magnitude of depolarization-induced SR Ca2+ depletion were found to be unchanged in mdx fibers, but the rate of the recovery phase that followed depletion was found to be faster, indicating a higher SR Ca2+ reuptake activity in mdx fibers. Overall, CPA-induced SR Ca2+ leak at −80 mV was found to be significantly higher in mdx fibers and was potentiated by removal of external Ca2+ in control fibers. The elevated passive SR Ca2+ leak may contribute to alteration of Ca2+ homeostasis in mdx muscle.

Structural proteins of the opaque muscle fibers in Duchenne muscular dystrophy

Neurology ◽  
1985 ◽  
Vol 35 (9) ◽  
pp. 1364-1364 ◽  
Author(s):  
M. Uchino ◽  
S. Araki ◽  
O. Yoshida ◽  
K. Uekawa
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Fibers ◽  
Structural Proteins

Levels of enzymes of energy metabolism are controlled by activity of cultured rat myotubes

1983 ◽  
Vol 244 (5) ◽  
pp. C348-C355 ◽  
Author(s):  
J. C. Lawrence ◽  
W. J. Salsgiver
Keyword(s):  
Energy Metabolism ◽  
Muscle Activity ◽  
Cultured Cells ◽  
Contractile Activity ◽  
Muscle Fibers ◽  
Oxidative Enzymes ◽  
Ionophore A23187 ◽  
Enzymes Of Energy Metabolism ◽  
Types Of Muscle Fibers

We have investigated the effects of inhibiting the spontaneous activity of cultured rat myotubes on several representative enzymes of glycolytic and oxidative metabolism. The results presented demonstrate that contractile activity in the absence of nerves can regulate the amounts of these enzymes and indicate that muscle activity may partially control development of the metabolic types of muscle fibers. Control muscle cells have relatively high levels of glycolytic enzymes and low oxidative enzymes and metabolically most closely resemble fast glycolytic fibers. The divalent cation ionophore A23187 caused enzyme levels of the cultured cells to change towards those found in tonically contracting skeletal muscle fibers in vivo. The evidence presented suggests that calcium may mediate certain of the effects associated with muscle contraction on enzymes of energy metabolism.

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