P4.26 Toward the identification of druggable pathways involved in disease-related fatigue in Duchenne muscular dystrophy: In vivo and ex vivo studies in dystrophic mdx mice

2011 ◽  
Vol 21 (9-10) ◽  
pp. 712
Author(s):  
R.F. Capogrosso ◽  
A. Cozzoli ◽  
V. Sblendorio ◽  
G.M. Camerino ◽  
R.W. Grange ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Ex Vivo ◽  
Mdx Mice

scholarly journals Soluble guanylate cyclase stimulation mitigates skeletal and cardiac muscle dysfunction in a mdx model of Duchenne muscular dystrophy

2021 ◽  
Author(s):  
Ling Zhang ◽  
Yuanyuan Xu ◽  
Keyvan Yousefi ◽  
Camila I. Irion ◽  
Roger A. Alvarez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Signal Propagation ◽  
Guanosine Monophosphate ◽  
Muscle Pathology ◽  
Mdx Mice

AbstractThe impairment of neuronal nitric oxide synthase (nNOS) signaling contributes to disease pathology in the muscle wasting disorder Duchenne muscular dystrophy (DMD). nNOS signal propagation occurs through nitric oxide sensitive soluble guanylate cyclase (sGC), a critical source of cyclic guanosine monophosphate (cGMP) in muscle. Although both nNOS and sGC activity are impaired in DMD patients, little is known about sGC as a therapeutic target. In this study, we tested the hypothesis that stimulating sGC activity with the allosteric agonist BAY41-8543 mitigates striated muscle pathology in the mdx4cv mouse model of DMD. In contrast to DMD patients, mdx mice exhibited greater basal sGC activity than wild type controls with preservation of cGMP levels due partly to upregulation of sGC in some muscles. Stimulating sGC activity in mdx mice with BAY41-8543 substantially reduced skeletal muscle damage, macrophage densities and inflammation and significantly increased resistance to contraction-induced fatigue. BAY41-8543 also enhanced in vivo diaphragm function while reducing breathing irregularities suggesting improved respiratory function. BAY41-8543 attenuated cardiac hypertrophic remodeling, fibrosis and diastolic dysfunction including left atrium enlargement in aged mdx mice. Overall, sGC stimulation significantly mitigated skeletal and cardio-respiratory dysfunction in mdx4cv mice. Importantly, this study provides compelling pre-clinical evidence supporting sGC as a novel target in DMD and the repurposing of FDA-approved sGC stimulators, such as riociguat and veraciguat, as a novel therapeutic approach for DMD.

scholarly journals Ultrasonography validation for early alteration of diaphragm echodensity and function in the mdx mouse model of Duchenne muscular dystrophy

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245397
Author(s):  
Antonietta Mele ◽  
Paola Mantuano ◽  
Adriano Fonzino ◽  
Francesco Rana ◽  
Roberta Francesca Capogrosso ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Ex Vivo ◽  
Eccentric Contraction ◽  
Invasive Technique ◽  
Mdx Mouse ◽  
Early Stages ◽  
Over Time

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.

scholarly journals Targeting fibrosis in the Duchenne Muscular Dystrophy mice model: an uphill battle

2021 ◽  
Author(s):  
Marine Theret ◽  
Marcela Low ◽  
Lucas Rempel ◽  
Fang Fang Li ◽  
Lin Wei Tung ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Large Scale ◽  
Drug Screen ◽  
Mdx Mice ◽  
Mice Model ◽  
Positive Effects ◽  
In Vitro Drug Screening

AbstractAimFibrosis is the most common complication from chronic diseases, and yet no therapy capable of mitigating its effects is available. Our goal is to unveil specific signallings regulating the fibrogenic process and to identify potential small molecule candidates that block fibrogenic differentiation of fibro/adipogenic progenitors.MethodWe performed a large-scale drug screen using muscle-resident fibro/adipogenic progenitors from a mouse model expressing EGFP under the Collagen1a1 promotor. We first confirmed that the EGFP was expressed in response to TGFβ1 stimulation in vitro. Then we treated cells with TGFβ1 alone or with drugs from two libraries of known compounds. The drugs ability to block the fibrogenic differentiation was quantified by imaging and flow cytometry. From a two-rounds screening, positive hits were tested in vivo in the mice model for the Duchenne muscular dystrophy (mdx mice). The histopathology of the muscles was assessed with picrosirius red (fibrosis) and laminin staining (myofiber size).Key findingsFrom the in vitro drug screening, we identified 21 drugs and tested 3 in vivo on the mdx mice. None of the three drugs significantly improved muscle histopathology.SignificanceThe in vitro drug screen identified various efficient compounds, none of them strongly inhibited fibrosis in skeletal muscle of mdx mice. To explain these observations, we hypothesize that in Duchenne Muscular Dystrophy, in which fibrosis is a secondary event due to chronic degeneration and inflammation, the drugs tested could have adverse effect on regeneration or inflammation, balancing off any positive effects and leading to the absence of significant results.

scholarly journals Menstrual Blood-derived Cells Confer Human Dystrophin Expression in the Murine Model of Duchenne Muscular Dystrophy via Cell Fusion and Myogenic Transdifferentiation

2007 ◽  
Vol 18 (5) ◽  
pp. 1586-1594 ◽  
Author(s):  
Chang-Hao Cui ◽  
Taro Uyama ◽  
Kenji Miyado ◽  
Masanori Terai ◽  
Satoru Kyo ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Progenitor Cells ◽  
Cell Fusion ◽  
Menstrual Blood ◽  
Mdx Mice ◽  
Dystrophin Expression ◽  
Human Dystrophin

Duchenne muscular dystrophy (DMD), the most common lethal genetic disorder in children, is an X-linked recessive muscle disease characterized by the absence of dystrophin at the sarcolemma of muscle fibers. We examined a putative endometrial progenitor obtained from endometrial tissue samples to determine whether these cells repair muscular degeneration in a murine mdx model of DMD. Implanted cells conferred human dystrophin in degenerated muscle of immunodeficient mdx mice. We then examined menstrual blood–derived cells to determine whether primarily cultured nontransformed cells also repair dystrophied muscle. In vivo transfer of menstrual blood–derived cells into dystrophic muscles of immunodeficient mdx mice restored sarcolemmal expression of dystrophin. Labeling of implanted cells with enhanced green fluorescent protein and differential staining of human and murine nuclei suggest that human dystrophin expression is due to cell fusion between host myocytes and implanted cells. In vitro analysis revealed that endometrial progenitor cells and menstrual blood–derived cells can efficiently transdifferentiate into myoblasts/myocytes, fuse to C2C12 murine myoblasts by in vitro coculturing, and start to express dystrophin after fusion. These results demonstrate that the endometrial progenitor cells and menstrual blood–derived cells can transfer dystrophin into dystrophied myocytes through cell fusion and transdifferentiation in vitro and in vivo.

Contractile efficiency of dystrophic mdx mouse muscle: in vivo and ex vivo assessment of adaptation to exercise of functional end points

2017 ◽  
Vol 122 (4) ◽  
pp. 828-843 ◽  
Author(s):  
Roberta Francesca Capogrosso ◽  
Paola Mantuano ◽  
Anna Cozzoli ◽  
Francesca Sanarica ◽  
Ada Maria Massari ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Damage ◽  
Functional Adaptation ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Chronic Exercise ◽  
Exercise Protocol ◽  
Dystrophic Muscle

Progressive weakness is a typical feature of Duchenne muscular dystrophy (DMD) patients and is exacerbated in the benign mdx mouse model by in vivo treadmill exercise. We hypothesized a different threshold for functional adaptation of mdx muscles in response to the duration of the exercise protocol. In vivo weakness was confirmed by grip strength after 4, 8, and 12 wk of exercise in mdx mice. Torque measurements revealed that exercise-related weakness in mdx mice correlated with the duration of the protocol, while wild-type (WT) mice were stronger. Twitch and tetanic forces of isolated diaphragm and extensor digitorum longus (EDL) muscles were lower in mdx compared with WT mice. In mdx, both muscle types exhibited greater weakness after a single exercise bout, but only in EDL after a long exercise protocol. As opposite to WT muscles, mdx EDL ones did not show any exercise-induced adaptations against eccentric contraction force drop. qRT-PCR analysis confirmed the maladaptation of genes involved in metabolic and structural remodeling, while damage-related genes remained significantly upregulated and angiogenesis impaired. Phosphorylated AMP kinase level increased only in exercised WT muscle. The severe histopathology and the high levels of muscular TGF-β1 and of plasma matrix metalloproteinase-9 confirmed the persistence of muscle damage in mdx mice. Therefore, dystrophic muscles showed a partial degree of functional adaptation to chronic exercise, although not sufficient to overcome weakness nor signs of damage. The improved understanding of the complex mechanisms underlying maladaptation of dystrophic muscle paves the way to a better managment of DMD patients. NEW & NOTEWORTHY We focused on the adaptation/maladaptation of dystrophic mdx mouse muscles to a standard protocol of exercise to provide guidance in the development of more effective drug and physical therapies in Duchenne muscular dystrophy. The mdx muscles showed a modest functional adaptation to chronic exercise, but it was not sufficient to overcome the progressive in vivo weakness, nor to counter signs of muscle damage. Therefore, a complex involvement of multiple systems underlies the maladaptive response of dystrophic muscle.

Cell-penetrating peptide–morpholino conjugates alter pre-mRNA splicing of DMD (Duchenne muscular dystrophy) and inhibit murine coronavirus replication in vivo

2007 ◽  
Vol 35 (4) ◽  
pp. 826-828 ◽  
Author(s):  
H.M. Moulton ◽  
S. Fletcher ◽  
B.W. Neuman ◽  
G. McClorey ◽  
D.A. Stein ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Canine Model ◽  
Cell Penetrating Peptides ◽  
Mdx Mice ◽  
Rna Targets ◽  
Cell Penetrating ◽  
Neonatal Stage ◽  
Murine Coronavirus

The cellular uptake of PMOs (phosphorodiamidate morpholino oligomers) can be enhanced by their conjugation to arginine-rich CPPs (cell-penetrating peptides). Here, we discuss our recent findings regarding (R-Ahx-R)4AhxB (Ahx is 6-aminohexanoic acid and B is β-alanine) CPP–PMO conjugates in DMD (Duchenne muscular dystrophy) and murine coronavirus research. An (R-Ahx-R)4AhxB–PMO conjugate was the most effective compound in inducing the correction of mutant dystrophin transcripts in myoblasts derived from a canine model of DMD. Similarly, normal levels of dystrophin expression were restored in the diaphragms of mdx mice, with treatment starting at the neonatal stage, and protein was still detecTable 22 weeks after the last dose of an (R-Ahx-R)4AhxB–PMO conjugate. Effects of length, linkage and carbohydrate modification of this CPP on the delivery of a PMO were investigated in a coronavirus mouse model. An (R-Ahx-R)4AhxB–PMO conjugate effectively inhibited viral replication, in comparison with other peptides conjugated to the same PMO. Shortening the CPP length, modifying it with a mannosylated serine moiety or replacing it with the R9F2 CPP significantly decreased the efficacy of the resulting PPMO (CPP–PMO conjugate). We attribute the success of this CPP to its stability in serum and its capacity to transport PMO to RNA targets in a manner superior to that of poly-arginine CPPs.

scholarly journals Investigating the Potential for Sulforaphane to Attenuate Gastrointestinal Dysfunction in mdx Dystrophic Mice

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4559
Author(s):  
Kristy Swiderski ◽  
Suzannah J. Read ◽  
Audrey S. Chan ◽  
Jin D. Chung ◽  
Jennifer Trieu ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Corn Oil ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Muscle Pathology ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Dystrophic Mice

Gastrointestinal (GI) dysfunction is an important, yet understudied condition associated with Duchenne muscular dystrophy (DMD), with patients reporting bloating, diarrhea, and general discomfort, contributing to a reduced quality of life. In the mdx mouse, the most commonly used mouse model of DMD, studies have confirmed GI dysfunction (reported as altered contractility and GI transit through the small and large intestine), associated with increased local and systemic inflammation. Sulforaphane (SFN) is a natural isothiocyanate with anti-inflammatory and anti-oxidative properties via its activation of Nrf2 signalling that has been shown to improve aspects of the skeletal muscle pathology in dystrophic mice. Whether SFN can similarly improve GI function in muscular dystrophy was unknown. Video imaging and spatiotemporal mapping to assess gastrointestinal contractions in isolated colon preparations from mdx and C57BL/10 mice revealed that SFN reduced contraction frequency when administered ex vivo, demonstrating its therapeutic potential to improve GI function in DMD. To confirm this in vivo, four-week-old male C57BL/10 and mdx mice received vehicle (2% DMSO/corn oil) or SFN (2 mg/kg in 2% DMSO/corn oil) via daily oral gavage five days/week for 4 weeks. SFN administration reduced fibrosis in the diaphragm of mdx mice but did not affect other pathological markers. Gene and protein analysis revealed no change in Nrf2 protein expression or activation of Nrf2 signalling after SFN administration and oral SFN supplementation did not improve GI function in mdx mice. Although ex vivo studies demonstrate SFN’s therapeutic potential for reducing colon contractions, in vivo studies should investigate higher doses and/or alternate routes of administration to confirm SFN’s potential to improve GI function in DMD.

scholarly journals Age-Dependent Dysregulation of Muscle Vasculature and Blood Flow Recovery after Hindlimb Ischemia in the mdx Model of Duchenne Muscular Dystrophy

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 481
Author(s):  
Paulina Podkalicka ◽  
Olga Mucha ◽  
Katarzyna Kaziród ◽  
Iwona Bronisz-Budzyńska ◽  
Sophie Ostrowska-Paton ◽  
...  
Keyword(s):  
Blood Flow ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Blood Vessels ◽  
Mdx Mice ◽  
Hindlimb Ischemia ◽  
Double Positive ◽  
Functional Studies ◽  
Age Dependent ◽  
Dystrophic Mice

Duchenne muscular dystrophy (DMD), caused by a lack of functional dystrophin, is characterized by progressive muscle degeneration. Interestingly, dystrophin is also expressed in endothelial cells (ECs), and insufficient angiogenesis has already been hypothesized to contribute to DMD pathology, however, its status in mdx mice, a model of DMD, is still not fully clear. Our study aimed to reveal angiogenesis-related alterations in skeletal muscles of mdx mice compared to wild-type (WT) counterparts. By investigating 6- and 12-week-old mice, we sought to verify if those changes are age-dependent. We utilized a broad spectrum of methods ranging from gene expression analysis, flow cytometry, and immunofluorescence imaging to determine the level of angiogenic markers and to assess muscle blood vessel abundance. Finally, we implemented the hindlimb ischemia (HLI) model, more biologically relevant in the context of functional studies evaluating angiogenesis/arteriogenesis processes. We demonstrated that both 6- and 12-week-old dystrophic mice exhibited dysregulation of several angiogenic factors, including decreased vascular endothelial growth factor A (VEGF) in different muscle types. Nonetheless, in younger, 6-week-old mdx animals, neither the abundance of CD31+α-SMA+ double-positive blood vessels nor basal blood flow and its restoration after HLI was affected. In 12-week-old mdx mice, although a higher number of CD31+α-SMA+ double-positive blood vessels and an increased percentage of skeletal muscle ECs were found, the abundance of pericytes was diminished, and blood flow was reduced. Moreover, impeded perfusion recovery after HLI associated with a blunted inflammatory and regenerative response was evident in 12-week-old dystrophic mice. Hence, our results reinforce the hypothesis of age-dependent angiogenic dysfunction in dystrophic mice. In conclusion, we suggest that older mdx mice constitute an appropriate model for preclinical studies evaluating the effectiveness of vascular-based therapies aimed at the restoration of functional angiogenesis to mitigate DMD severity.

Have Duchenne Muscular Dystrophy Patients an Increased Cancer Risk?

2021 ◽  
pp. 1-5
Author(s):  
Gian Luca Vita ◽  
Luisa Politano ◽  
Angela Berardinelli ◽  
Giuseppe Vita
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Systematic Investigation ◽  
Mdx Mice ◽  
True Incidence ◽  
Patients With Cancer ◽  
Dmd Gene ◽  
Age Range ◽  
Prevalence Of Cancer

Background: Increasing evidence suggests that Duchenne muscular dystrophy (DMD) gene is involved in the occurrence of different types of cancer. Moreover, development of sarcomas was reported in mdx mice, the murine model of DMD, in older age. So far, nine isolated DMD patients were reported with concomitant cancer, four of whom with rhabdomyosarcoma (RMS), but no systematic investigation was performed about the true incidence of cancer in DMD. Methods: All members of the Italian Association of Myology were asked about the occurrence of cancer in their DMD patients in the last 30 years. Results: Four DMD patients with cancer were reported after checking 2455 medical records. One developed brain tumour at the age of 35 years. Two patients had alveolar RMS at 14 and 17 years of age. The fourth patient had a benign enchondroma when 11-year-old. Conclusion: Prevalence of cancer in general in the Italian DMD patients does not seem to be different from that in the general population with the same age range. Although the small numbers herein presented do not allow definitive conclusion, the frequent occurrence of RMS in DMD patients raises an alert for basic researchers and clinicians. The role of DMD gene in cancer merits further investigations.

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