scholarly journals Reversal of cardiac and skeletal manifestations of Duchenne muscular dystrophy by cardiosphere-derived cells and their exosomes in mdx dystrophic mice and in human Duchenne cardiomyocytes

2017 ◽  
Author(s):  
Mark A. Aminzadeh ◽  
Russell G. Rogers ◽  
Kenneth Gouin ◽  
Mario Fournier ◽  
Rachel E. Tobin ◽  
...  

Genetic deficiency of dystrophin leads to disability and premature death in Duchenne muscular dystrophy, affecting the heart as well as skeletal muscle. Here we report that cardiosphere-derived cells (CDCs), which are being tested clinically for the treatment of Duchenne cardiomyopathy, improve cardiac and skeletal myopathy in the mdx mouse model of DMD and in human Duchenne cardiomyocytes. Injection of CDCs into the hearts of mdx mice augments cardiac function, ambulatory capacity and survival. Exosomes secreted by human CDCs reproduce the benefits of CDCs in mdx mice and in human Duchenne cardiomyocytes. The findings further motivate the testing of CDCs in Duchenne patients, while identifying exosomes as next-generation therapeutic candidates.

Author(s):  
Ray Mitchell ◽  
Norman E Frederick ◽  
Emily R Holzman ◽  
Francesca Agobe ◽  
Heather C M Allaway ◽  
...  

Dilated cardiomyopathy contributes to morbidity and mortality in Duchenne Muscular Dystrophy (DMD), an inheritable muscle wasting disease caused by a mutation in the dystrophin gene. Preclinical studies in mouse models of muscular dystrophy have demonstrated reduced cardiomyopathy and improved cardiac function following oral treatment with the potent and selective thromboxane A2/prostanoid receptor (TPr) antagonist, ifetroban. Further, a phase 2 clinical trial (NCT03340675, Cumberland Pharmaceutical) is currently recruiting subjects to determine if ifetroban can improve cardiac function in patients with DMD. Although TPr is a promising therapeutic target for the treatment of dilated cardiomyopathy in DMD, little is known about TPr function in coronary arteries that perfuse blood through the cardiac tissue. In the current study, isolated coronary arteries from young (~3-5 months) and aged (~9-12 months) mdx mice, a widely used mouse model of DMD, and age-matched controls were examined using wire myography. Vasoconstriction to increasing concentrations of TPr agonist U-46619(U4) was enhanced in young mdx mice versus controls. Additionally, young mdx mice displayed a significant attenuation in endothelial cell-mediated vasodilation to increasing concentrations of the muscarinic agonist acetylcholine (ACh). Since TPr activation was enhanced in young mdx mice, U4-mediated vasoconstriction was measured in the absence and presence of ifetroban. Ifetroban reduced U4-mediated vasoconstriction in young mdx and both aged mdx and control mice. Overall, our data demonstrate enhanced coronary arterial vasoconstriction to TPr activation in young mdx mice, a phenotype that could be reversed with ifetroban. These data could have important therapeutic implications for improving cardiovascular function in DMD.


2021 ◽  
Author(s):  
Xiaodong Zhou ◽  
Hongsheng Ouyang ◽  
Daxin Pang ◽  
Renzhi Han ◽  
Xiaochun Tang

Abstract Patients with Duchenne muscular dystrophy (DMD) develop severe skeletal and cardiac muscle pathologies, which result in premature death. Therefore, the current therapeutic efforts are mainly targeted to correct dystrophin expression in skeletal muscle and heart. However, it was reported that DMD patients may also exhibit gastrointestinal and nutritional problems. How the pathological alterations in gastrointestinal tissues may contribute to the disease are not fully explored. Here we employed the CRISPR/Cas9 system combined with somatic nuclear transfer technology (SCNT) to establish a porcine model of DMD and explored their pathological alterations. We found that genetic disruption of dystrophin expression led1 to morphological gastrointestinal tract alterations, weakened the gastrointestinal tract digestion and absorption capacity, and eventually led to malnutrition and gastric dysfunction in the DMD pigs. This work provides important insights into the pathogenesis of DMD and highlights the need to consider the gastrointestinal dysfunction as an additional therapeutic target for DMD patients.


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

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.


2020 ◽  
Author(s):  
Justin S. Dhindsa ◽  
Angela L. McCall ◽  
Laura M. Strickland ◽  
Anna F. Fusco ◽  
Amanda F. Kahn ◽  
...  

AbstractSkeletal muscle weakness due to loss of dystrophin is a well-documented pathological hallmark of Duchenne muscular dystrophy (DMD). In contrast, the neuropathology of this disease remains understudied. Here, we characterize an axonopathy in the phrenic and hypoglossal (XII) nerves of mdx mice. We observe nerve dysfunction that we propose contributes to respiratory failure, the most common cause of death in DMD.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Alex C Chang ◽  
Sang-Ging Ong ◽  
Joseph Wu ◽  
Helen M Blau

Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive disease that is result of mutations in the dystrophin gene and is the most common myopathic disease in humans with a prevalence of one in every 3500 males. Dystrophin is crucial for the formation of a dystrophin-glycoprotein complex (DGC), which connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix in both skeletal and cardiac muscles. In the heart, loss of dystrophin leads to increased fibrosis and death in the third decade of life due to dilated cardiomyopathy. A conundrum in studying and developing therapies for DMD has been the lack of a mouse model that fully recapitulates the clinical phenotype, as mice that lack dystrophin (mdx model), unlike patients, exhibit only mild skeletal muscle defects, essentially no cardiac defects and have a relatively normal lifespan. Our lab reasoned that the difference in the manifestation of the disease in mice and humans could be telomere length, as mice have substantially longer telomeres than humans. We created a novel mouse model with shortened telomere lengths (similar to humans) that fully recapitulates the skeletal muscle (Cell. 2010;143:1059-1071; the mdx/mTRKO model) and cardiac muscle phenotype of DMD (Nat Cell Biol. 2013; 15:895-904; dilated cardiomyopathy). Interestingly, we observed a relative 45% reduction in cardiomyocyte telomere length in our mdx/mTRKO animals (3 animals per group, N = 300-400) as well as patient samples (4 DMD patient samples, N = 40-95). Here we present new evidence of mitochondrial dysfunction and telomere dysfunction.


2016 ◽  
Vol 594 (11) ◽  
pp. 3095-3110 ◽  
Author(s):  
Jessica R. Terrill ◽  
Gavin J. Pinniger ◽  
Jamie A. Graves ◽  
Miranda D. Grounds ◽  
Peter G. Arthur

2021 ◽  
Vol 23 (1) ◽  
pp. 470
Author(s):  
Olga Mucha ◽  
Katarzyna Kaziród ◽  
Paulina Podkalicka ◽  
Kinga Rusin ◽  
Józef Dulak ◽  
...  

Dysregulation of autophagy may contribute to the progression of various muscle diseases, including Duchenne muscular dystrophy (DMD). Heme oxygenase-1 (HO-1, encoded by Hmox1), a heme-degrading enzyme, may alleviate symptoms of DMD, inter alia, through anti-inflammatory properties. In the present study, we determined the role of HO-1 in the regulation of autophagy and mitophagy in mdx animals, a commonly used mouse model of the disease. In the gastrocnemius of 6-week-old DMD mice, the mRNA level of mitophagy markers: Bnip3 and Pink1, as well as autophagy regulators, e.g., Becn1, Map1lc3b, Sqstm1, and Atg7, was decreased. In the dystrophic diaphragm, changes in the latter were less prominent. In older, 12-week-old dystrophic mice, diminished expressions of Pink1 and Sqstm1 with upregulation of Atg5, Atg7, and Lamp1 was depicted. Interestingly, we demonstrated higher protein levels of autophagy regulator, LC3, in dystrophic muscles. Although the lack of Hmox1 in mdx mice influenced blood cell count and the abundance of profibrotic proteins, no striking differences in mRNA and protein levels of autophagy and mitophagy markers were found. In conclusion, we demonstrated complex, tissue, and age-dependent dysregulation of mitophagic and autophagic markers in DMD mice, which are not affected by the additional lack of Hmox1.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Corinne A. Betts ◽  
Amer F. Saleh ◽  
Carolyn A. Carr ◽  
Sofia Muses ◽  
Kim E. Wells ◽  
...  

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