scholarly journals The Effect of Vitamin D Supplementation on Skeletal Muscle in the mdx Mouse Model of Duchenne Muscular Dystrophy

Sports ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 96
Author(s):  
Danielle A. Debruin ◽  
Nicola Andreacchio ◽  
Erik D. Hanson ◽  
Cara A. Timpani ◽  
Emma Rybalka ◽  
...  

Vitamin D (VitD) has shown to be beneficial in reversing muscle weakness and atrophy associated with VitD deficiency. Duchenne muscular dystrophy is characterized by worsening muscle weakness and muscle atrophy, with VitD deficiency commonly observed. This study aimed to investigate the effect of VitD supplementation on dystrophic skeletal muscle. Eight-week old female control (C57BL/10; n = 29) and dystrophic (C57BL/mdx; n = 23) mice were randomly supplemented with one of three VitD enriched diets (1000, 8000 & 20,000 IU/kg chow). Following a four-week feeding period, the extensor digitorum longus (EDL) and soleus muscles contractile and fatigue properties were tested ex vivo, followed by histological analysis. As expected, mdx muscles displayed higher mass yet lower specific forces and a rightward shift in their force frequency relationship consistent with dystrophic pathology. There was a trend for mdx muscle mass to be larger following the 20,000 IU/kg diet, but this did not result in improved force production. Fiber area in the EDL was larger in mdx compared to controls, and there were higher amounts of damage in both muscles, with VitD supplementation having no effect. Four weeks of VitD supplementation did not appear to have any impact upon dystrophic skeletal muscle pathology at this age.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David W. Hammers ◽  
Cora C. Hart ◽  
Michael K. Matheny ◽  
Lillian A. Wright ◽  
Megan Armellini ◽  
...  

2019 ◽  
Vol 28 (16) ◽  
pp. 2686-2695 ◽  
Author(s):  
Pamela Barraza-Flores ◽  
Tatiana M Fontelonga ◽  
Ryan D Wuebbles ◽  
Hailey J Hermann ◽  
Andreia M Nunes ◽  
...  

Abstract Duchenne muscular dystrophy (DMD) is a devastating X-linked disease affecting ~1 in 5000 males. DMD patients exhibit progressive muscle degeneration and weakness, leading to loss of ambulation and premature death from cardiopulmonary failure. We previously reported that mouse Laminin-111 (msLam-111) protein could reduce muscle pathology and improve muscle function in the mdx mouse model for DMD. In this study, we examined the ability of msLam-111 to prevent muscle disease progression in the golden retriever muscular dystrophy (GRMD) dog model of DMD. The msLam-111 protein was injected into the cranial tibial muscle compartment of GRMD dogs and muscle strength and pathology were assessed. The results showed that msLam-111 treatment increased muscle fiber regeneration and repair with improved muscle strength and reduced muscle fibrosis in the GRMD model. Together, these findings support the idea that Laminin-111 could serve as a novel protein therapy for the treatment of DMD.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Nadia Milad ◽  
Zoe White ◽  
Arash Y. Tehrani ◽  
Stephanie Sellers ◽  
Fabio M.V. Rossi ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245397
Author(s):  
Antonietta Mele ◽  
Paola Mantuano ◽  
Adriano Fonzino ◽  
Francesco Rana ◽  
Roberta Francesca Capogrosso ◽  
...  

The mdx mouse model of Duchenne muscular dystrophy is characterized by functional and structural alterations of the diaphragm since early stages of pathology, closely resembling patients’ condition. In recent years, ultrasonography has been proposed as a useful longitudinal non-invasive technique to assess mdx diaphragm dysfunction and evaluate drug efficacy over time. To date, only a few preclinical studies have been conducted. Therefore, an independent validation of this method by different laboratories is needed to increase results reliability and reduce biases. Here, we performed diaphragm ultrasonography in 3- and 6-month-old mdx mice, the preferred age-window for pharmacology studies. The alteration of diaphragm function over time was measured as diaphragm ultrasound movement amplitude. At the same time points, a first-time assessment of diaphragm echodensity was performed, as an experimental index of progressive loss of contractile tissue. A parallel evaluation of other in vivo and ex vivo dystrophy-relevant readouts was carried out. Both 3- and 6-month-old mdx mice showed a significant decrease in diaphragm amplitude compared to wild type (wt) mice. This index was well-correlated either with in vivo running performance or ex vivo isometric tetanic force of isolated diaphragm. In addition, diaphragms from 6-month-old dystrophic mice were also highly susceptible to eccentric contraction ex vivo. Importantly, we disclosed an age-dependent increase in echodensity in mdx mice not observed in wt animals, which was independent from abdominal wall thickness. This was accompanied by a notable increase of pro-fibrotic TGF-β1 levels in the mdx diaphragm and of non-muscle tissue amount in diaphragm sections stained by hematoxylin & eosin. Our findings corroborate the usefulness of diaphragm ultrasonography in preclinical drug studies as a powerful tool to monitor mdx pathology progression since early stages.


2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Nicolette Johnson ◽  
Jennifer Levy ◽  
Isabella Grumbach ◽  
Mark Anderson ◽  
Kevin Campbell

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Segatto ◽  
Roberta Szokoll ◽  
Raffaella Fittipaldi ◽  
Cinzia Bottino ◽  
Lorenzo Nevi ◽  
...  

AbstractDuchenne muscular dystrophy (DMD) affects 1 in 3500 live male births. To date, there is no effective cure for DMD, and the identification of novel molecular targets involved in disease progression is important to design more effective treatments and therapies to alleviate DMD symptoms. Here, we show that protein levels of the Bromodomain and extra-terminal domain (BET) protein BRD4 are significantly increased in the muscle of the mouse model of DMD, the mdx mouse, and that pharmacological inhibition of the BET proteins has a beneficial outcome, tempering oxidative stress and muscle damage. Alterations in reactive oxygen species (ROS) metabolism are an early event in DMD onset and they are tightly linked to inflammation, fibrosis, and necrosis in skeletal muscle. By restoring ROS metabolism, BET inhibition ameliorates these hallmarks of the dystrophic muscle, translating to a beneficial effect on muscle function. BRD4 direct association to chromatin regulatory regions of the NADPH oxidase subunits increases in the mdx muscle and JQ1 administration reduces BRD4 and BRD2 recruitment at these regions. JQ1 treatment reduces NADPH subunit transcript levels in mdx muscles, isolated myofibers and DMD immortalized myoblasts. Our data highlight novel functions of the BET proteins in dystrophic skeletal muscle and suggest that BET inhibitors may ameliorate the pathophysiology of DMD.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Julie Nouet ◽  
Eric Himelman ◽  
Diego Fraidenraich

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.


2001 ◽  
Vol 47 (3) ◽  
pp. 451-458 ◽  
Author(s):  
Angelika Hammerer-Lercher ◽  
Petra Erlacher ◽  
Reginald Bittner ◽  
Rudolf Korinthenberg ◽  
Daniela Skladal ◽  
...  

Abstract Background: Because of controversial earlier studies, the purpose of this study was to provide novel experimental and additional clinical data regarding the possible reexpression of cardiac troponin T (cTnT) in regenerating skeletal muscle in Duchenne muscular dystrophy (DMD). Methods: Plasma from 14 patients (mean age, 7.5 years; range, 5.7–19.4 years) with DMD was investigated for creatine kinase (CK), the CK MB isoenzyme (CKMB), cTnT and cardiac troponin I (cTnI), and myoglobin. cTnT concentrations were measured by an ELISA (second-generation assay; Roche) using the ES 300 Analyzer. cTnI, myoglobin, and CKMB were measured by an ELISA using the ACCESS System (Beckman Diagnostics). Troponin isoform expression was studied by Western blot analysis in remnants of skeletal muscle biopsies of three patients with DMD and in an animal model of DMD (mdx mice; n = 6). Results: There was no relation of cTnT and cTnI to clinical evidence for cardiac failure. cTnI concentrations remained below the upper reference limit in all patients. cTnT was increased (median, 0.11 μg/L; range, 0.06–0.16 μg/L) in 50% of patients. The only significant correlation was found for CK (median, 3938 U/L; range, 2763–5030 U/L) with age (median, 7.5 years; range, 6.8–10.9 years; r = −0.762; P = 0.042). Western blot analysis of human or mouse homogenized muscle specimens showed no evidence for cardiac TnT and cTnI expression, despite strong signals for skeletal muscle troponin isoforms. Conclusions: We found no evidence for cTnT reexpression in human early-stage DMD and in mdx mouse skeletal muscle biopsies. Discrepancies of cTnT and cTnI in plasma samples of DMD patients were found, but neither cTnT nor cTnI plasma concentrations were related with other clinical evidence for cardiac involvement.


Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4311-4318 ◽  
Author(s):  
Chiara Dell'Agnola ◽  
Zejing Wang ◽  
Rainer Storb ◽  
Stephen J. Tapscott ◽  
Christian S. Kuhr ◽  
...  

Abstract Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene on the X-chromosome that result in skeletal and cardiac muscle damage and premature death. Studies in mice, including the mdx mouse model of DMD, have demonstrated that circulating bone marrow–derived cells can participate in skeletal muscle regeneration, but the potential clinical utility of treating human DMD by allogeneic marrow transplantation from a healthy donor remains unknown. To assess whether allogeneic hematopoietic cell transplantation (HCT) provides clinically relevant levels of donor muscle cell contribution in dogs with canine X-linked muscular dystrophy (c-xmd), 7 xmd dogs were given hematopoietic cell (HC) transplants from nonaffected littermates. Compared with the pretransplantation baseline, the number of dystrophin-positive fibers and the amount of wild-type dystrophin RNA did not increase after HCT, with observation periods ranging from 28 to 417 days. Similar results were obtained when the recipient dogs were given granulocyte colony-stimulating factor (G-CSF) after their initial transplantation to mobilize the cells. Despite successful allogeneic HCT and a permissive environment for donor muscle engraftment, there was no detectable contribution of bone marrow–derived cells to either skeletal muscle or muscle precursor cells assayed by clonal analyses at a level of sensitivity that should detect as little as 0.1% donor contribution.


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