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1
Straub, Volker, Jill A. Rafael, Jeffrey S. Chamberlain, and Kevin P. Campbell. "Animal Models for Muscular Dystrophy Show Different Patterns of Sarcolemmal Disruption." Journal of Cell Biology 139, no. 2 (October 20, 1997): 375–85. http://dx.doi.org/10.1083/jcb.139.2.375.
Full textAbstract:
Genetic defects in a number of components of the dystrophin–glycoprotein complex (DGC) lead to distinct forms of muscular dystrophy. However, little is known about how alterations in the DGC are manifested in the pathophysiology present in dystrophic muscle tissue. One hypothesis is that the DGC protects the sarcolemma from contraction-induced damage. Using tracer molecules, we compared sarcolemmal integrity in animal models for muscular dystrophy and in muscular dystrophy patient samples. Evans blue, a low molecular weight diazo dye, does not cross into skeletal muscle fibers in normal mice. In contrast, mdx mice, a dystrophin-deficient animal model for Duchenne muscular dystrophy, showed significant Evans blue accumulation in skeletal muscle fibers. We also studied Evans blue dispersion in transgenic mice bearing different dystrophin mutations, and we demonstrated that cytoskeletal and sarcolemmal attachment of dystrophin might be a necessary requirement to prevent serious fiber damage. The extent of dye incorporation in transgenic mice correlated with the phenotypic severity of similar dystrophin mutations in humans. We furthermore assessed Evans blue incorporation in skeletal muscle of the dystrophia muscularis (dy/dy) mouse and its milder allelic variant, the dy2J/dy2J mouse, animal models for congenital muscular dystrophy. Surprisingly, these mice, which have defects in the laminin α2-chain, an extracellular ligand of the DGC, showed little Evans blue accumulation in their skeletal muscles. Taken together, these results suggest that the pathogenic mechanisms in congenital muscular dystrophy are different from those in Duchenne muscular dystrophy, although the primary defects originate in two components associated with the same protein complex.
2
Teramoto, Naomi, Hidetoshi Sugihara, Keitaro Yamanouchi, Katsuyuki Nakamura, Koichi Kimura, Tomoko Okano, Takanori Shiga, et al. "Pathological evaluation of rats carrying in-frame mutations in the dystrophin gene: a new model of Becker muscular dystrophy." Disease Models & Mechanisms 13, no. 9 (August 28, 2020): dmm044701. http://dx.doi.org/10.1242/dmm.044701.
Full textAbstract:
ABSTRACTDystrophin, encoded by the DMD gene on the X chromosome, stabilizes the sarcolemma by linking the actin cytoskeleton with the dystrophin-glycoprotein complex (DGC). In-frame mutations in DMD cause a milder form of X-linked muscular dystrophy, called Becker muscular dystrophy (BMD), characterized by the reduced expression of truncated dystrophin. So far, no animal model with in-frame mutations in Dmd has been established. As a result, the effect of in-frame mutations on the dystrophin expression profile and disease progression of BMD remains unclear. In this study, we established a novel rat model carrying in-frame Dmd gene mutations (IF rats) and evaluated the pathology. We found that IF rats exhibited reduced expression of truncated dystrophin in a proteasome-independent manner. This abnormal dystrophin expression caused dystrophic changes in muscle tissues but did not lead to functional deficiency. We also found that the expression of additional dystrophin named dpX, which forms the DGC in the sarcolemma, was associated with the appearance of truncated dystrophin. In conclusion, the outcomes of this study contribute to the further understanding of BMD pathology and help elucidate the efficiency of dystrophin recovery treatments in Duchenne muscular dystrophy, a more severe form of X-linked muscular dystrophy.
3
Spaulding, HR, C. Ballmann, JC Quindry, MB Hudson, and JT Selsby. "Autophagy in the heart is enhanced and independent of disease progression in mus musculus dystrophinopathy models." JRSM Cardiovascular Disease 8 (January 2019): 204800401987958. http://dx.doi.org/10.1177/2048004019879581.
Full textAbstract:
Background Duchenne muscular dystrophy is a muscle wasting disease caused by dystrophin gene mutations resulting in dysfunctional dystrophin protein. Autophagy, a proteolytic process, is impaired in dystrophic skeletal muscle though little is known about the effect of dystrophin deficiency on autophagy in cardiac muscle. We hypothesized that with disease progression autophagy would become increasingly dysfunctional based upon indirect autophagic markers. Methods Markers of autophagy were measured by western blot in 7-week-old and 17-month-old control (C57) and dystrophic (mdx) hearts. Results Counter to our hypothesis, markers of autophagy were similar between groups. Given these surprising results, two independent experiments were conducted using 14-month-old mdx mice or 10-month-old mdx/Utrn± mice, a more severe model of Duchenne muscular dystrophy. Data from these animals suggest increased autophagosome degradation. Conclusion Together these data suggest that autophagy is not impaired in the dystrophic myocardium as it is in dystrophic skeletal muscle and that disease progression and related injury is independent of autophagic dysfunction.
4
Steen, Michelle S., Marvin E. Adams, Yan Tesch, and Stanley C. Froehner. "Amelioration of Muscular Dystrophy by Transgenic Expression of Niemann-Pick C1." Molecular Biology of the Cell 20, no. 1 (January 2009): 146–52. http://dx.doi.org/10.1091/mbc.e08-08-0811.
Full textAbstract:
Duchenne muscular dystrophy (DMD) and other types of muscular dystrophies are caused by the loss or alteration of different members of the dystrophin protein complex. Understanding the molecular mechanisms by which dystrophin-associated protein abnormalities contribute to the onset of muscular dystrophy may identify new therapeutic approaches to these human disorders. By examining gene expression alterations in mouse skeletal muscle lacking α-dystrobrevin (Dtna−/−), we identified a highly significant reduction of the cholesterol trafficking protein, Niemann-Pick C1 (NPC1). Mutations in NPC1 cause a progressive neurodegenerative, lysosomal storage disorder. Transgenic expression of NPC1 in skeletal muscle ameliorates muscular dystrophy in the Dtna−/− mouse (which has a relatively mild dystrophic phenotype) and in the mdx mouse, a model for DMD. These results identify a new compensatory gene for muscular dystrophy and reveal a potential new therapeutic target for DMD.
5
Bergman, Robert L., Karen D. Inzana, William E. Monroe, Linda G. Shell, Ling A. Liu, Eva Engvall, and G. Diane Shelton. "Dystrophin-Deficient Muscular Dystrophy in a Labrador Retriever." Journal of the American Animal Hospital Association 38, no. 3 (May 1, 2002): 255–61. http://dx.doi.org/10.5326/0380255.
Full textAbstract:
Sex-linked muscular dystrophy associated with dystrophin deficiency has been reported in several breeds of dogs and is best characterized in the golden retriever. In this case report, a young, male Labrador retriever with dystrophin-deficient muscular dystrophy is presented. Clinical signs included generalized weakness, lingual hypertrophy, and dysphagia. Electromyographic abnormalities including complex repetitive discharges were present. Serum creatine kinase concentration was dramatically elevated. Histopathological changes within a muscle biopsy specimen confirmed a dystrophic myopathy, and dystrophin deficiency was demonstrated by immunohisto-chemical staining. While X-linked muscular dystrophy has not previously been reported in the Labrador retriever, a hereditary myopathy with an autosomal recessive mode of inheritance has been characterized. A correct diagnosis and classification of these two disorders are critical for breeders and owners since both the mode of inheritance and the prognosis differ.
6
Pelosi, Laura, Laura Forcina, Carmine Nicoletti, Bianca Maria Scicchitano, and Antonio Musarò. "Increased Circulating Levels of Interleukin-6 Induce Perturbation in Redox-Regulated Signaling Cascades in Muscle of Dystrophic Mice." Oxidative Medicine and Cellular Longevity 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1987218.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is an X-linked genetic disease in which dystrophin gene is mutated, resulting in dysfunctional or absent dystrophin protein. The pathology of dystrophic muscle includes degeneration, necrosis with inflammatory cell invasion, regeneration, and fibrous and fatty changes. Nevertheless, the mechanisms by which the absence of dystrophin leads to muscle degeneration remain to be fully elucidated. An imbalance between oxidant and antioxidant systems has been proposed as a secondary effect of DMD. However, the significance and precise extent of the perturbation in redox signaling cascades is poorly understood. We report that mdx dystrophic mice are able to activate a compensatory antioxidant response at the presymptomatic stage of the disease. In contrast, increased circulating levels of IL-6 perturb the redox signaling cascade, even prior to the necrotic stage, leading to severe features and progressive nature of muscular dystrophy.
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Baraibar-Churio, Arantxa, Míriam Bobadilla, Florencio J. D. Machado, Neira Sáinz, Carmen Roncal, Gloria Abizanda, Felipe Prósper, Josune Orbe, and Ana Pérez-Ruiz. "Deficiency of MMP-10 Aggravates the Diseased Phenotype of Aged Dystrophic Mice." Life 11, no. 12 (December 14, 2021): 1398. http://dx.doi.org/10.3390/life11121398.
Full textAbstract:
Matrix metalloproteinases (MMPs) have been implicated in the progression of muscular dystrophy, and recent studies have reported the role of MMP-10 in skeletal muscle pathology of young dystrophic mice. Nevertheless, its involvement in dystrophin-deficient hearts remains unexplored. Here, we aimed to investigate the involvement of MMP-10 in the progression of severe muscular dystrophy and to characterize MMP-10 loss in skeletal and cardiac muscles of aged dystrophic mice. We examined the histopathological effect of MMP-10 ablation in aged mdx mice, both in the hind limb muscles and heart tissues. We found that MMP-10 loss compromises survival rates of aged mdx mice, with skeletal and cardiac muscles developing a chronic inflammatory response. Our findings indicate that MMP-10 is implicated in severe muscular dystrophy progression, thus identifying a new area of research that could lead to future therapies for dystrophic muscles.
8
Sitzia, Clementina, Andrea Farini, Federica Colleoni, Francesco Fortunato, Paola Razini, Silvia Erratico, Alessandro Tavelli, et al. "Improvement of Endurance of DMD Animal Model Using Natural Polyphenols." BioMed Research International 2015 (2015): 1–17. http://dx.doi.org/10.1155/2015/680615.
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Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, is characterized by muscular wasting caused by dystrophin deficiency that ultimately ends in force reduction and premature death. In addition to primary genetic defect, several mechanisms contribute to DMD pathogenesis. Recently, antioxidant supplementation was shown to be effective in the treatment of multiple diseases including muscular dystrophy. Different mechanisms were hypothesized such as reduced hydroxyl radicals, nuclear factor-κB deactivation, and NO protection from inactivation. Following these promising evidences, we investigated the effect of the administration of a mix of dietary natural polyphenols (ProAbe) on dystrophic mdx mice in terms of muscular architecture and functionality. We observed a reduction of muscle fibrosis deposition and myofiber necrosis together with an amelioration of vascularization. More importantly, the recovery of the morphological features of dystrophic muscle leads to an improvement of the endurance of treated dystrophic mice. Our data confirmed that ProAbe-based diet may represent a strategy to coadjuvate the treatment of DMD.
9
Niebrój-Dobosz, Irena, and Irena Hausmanowa-Petrusewicz. "The involvement of oxidative stress in determining the severity and progress of pathological processes in dystrophin-deficient muscles." Acta Biochimica Polonica 52, no. 2 (May 25, 2005): 449–52. http://dx.doi.org/10.18388/abp.2005_3458.
Full textAbstract:
In both forms of muscular dystrophy, the severe Duchenne's muscular dystrophy (DMD) with lifespan shortened to about 20 years and the milder Becker dystrophy (BDM) with normal lifespan, the gene defect is located at chromosome locus Xp21. The location is the same in the experimental model of DMD in the mdx mice. As the result of the gene defect a protein called dystrophin is either not synthesized, or is produced in traces. Although the structure of this protein is rather well established there are still many controversies about the dystrophin function. The most accepted suggestion supposes that it stabilizes sarcolemma in the course of the contraction-relaxation cycle. Solving the problem of dystrophin function is a prerequisite for introduction of an effective therapy. Among the different factors which might be responsible for the appearance and progress of dystrophic changes in muscles there is an excessive action of oxidative stress. In this review data indicating the influence of oxidative stress on the severity of the pathologic processes in dystrophy are discussed. Several pieces of data indicating the action of oxidative damage to different macromolecules in DMD/BDM are presented. Special attention is devoted to the degree of oxidative damage to muscle proteins, the activity of neuronal nitric oxide synthase (nNOS) and their involvement in defining the severity of the dystrophic processes. It is indicated that the severity of the morbid process is related to the degree of oxidative damage to muscle proteins and the decrease of the nNOS activity in muscles. Estimation of the degree of the destructive action of oxidative stress in muscular dystrophy may be a useful marker facilitating introduction of an effective antioxidant therapy and regulation of nNOS activity.
10
Ibrahim Sory, P., T. Sidi, L. Guida, K. Boureima, M. Alassane Bameye, T. Mohomodine Ibrahim, K. Abdoulaye, and C. Idrissa Ahmadou. "Dystrophie Musculaire de Duchenne: Aspects cliniques, biologiques et évolutifs à propos de cinq cas dans le service de Rhumatologie au CHU du Point G." Rhumatologie Africaine Francophone 6, no. 2 (January 19, 2024): 18–23. http://dx.doi.org/10.62455/raf.v6i2.53.
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Résumé
La dystrophie musculaire de Duchenne (DMD) due à la non expression de la dystrophine est liée au chromosome X. Décrite au 19e siècle, est la plus courante dystrophie musculaire de l’enfant [1, 2]. L’incidence est estimée à 30 cas pour 100 000 naissances [1, 2].
But- étudier les caractères cliniques, biologiques et évolutifs de la dystrophie musculaire de Duchenne.
Patients et Méthodes :
Il s’est agi d’une étude rétrospective portant sur 5 dossiers de DMD, colligés en 7 ans.
Résultats
Nous rapportons cinq dossiers de garçons colligés entre 2005 et 2012,
2012, d’âge moyen de 7 ans avec des extrêmes de 1 et 12 ans. L’hypertrophie des mollets et la présence d’un signe de Gowers chez 4/5 patients. Le caractère familial était présent chez 2 garçons âgés de 5 et 10 ans à l’inclusion dont un mariage consanguin. L’examen anatomopathologique musculaire a conclu à des lésions dystrophiques. L’immunohistochimie n’a pas trouvé d’expression de la dystrophine. La corticothérapie précocement instituée à 0,5 mg/kg/jour associée à la rééducation kinésithérapie a maintenu l’autonomie des patients.
Conclusion
La corticothérapie retarderait les complications cardio-pulmonaires. Associée à la rééducation kinésithérapie et aux conseils pratiques elle a diminué les chutes.
Mots clés : Dystrophie – Musculaire – Duchenne, Rhumatologie Bamako
Abstract:
Introduction Duchenne’s muscular dystrophy (DMD) caused by no dystrophin expression is linked to X chromosome. Described in the 19th century, it is the most common muscular dystrophy of the child [1, 2]. The incidence is estimated at 30 cases per 100 000 births [1, 2]. Goal - Study clinical, biological and evolutive aspects of the Duchenne's Muscular Dystrophy.
Patients and Methods:
It was a retrospective study about 5 cases of DMD, collected in 7 years [2005-2012].
Results During our study from the period of 2005 to 2012, we had 5 cases of boys with an average age of 7 years and the extreme age from 1 year to 12 years. The calf’s hypertrophy and the presence of a Gowers’s sign in 4/5 patients. Family caracteristic was present in two boys aged 5 and 10 years with a consanguineous marriage. Muscular Histological examination concluded dystrophic lesions. The immunohistiochemistry found no expression of dystrophin. Corticosteroids early established at 0.5 mg / kg / day combined with physiotherapy rehabilitation maintained the autonomy of patients. .
Conclusion Corticosteroids would slow douwn cardiopulmonary complications. Associated with the physiotherapy rehabilitation and practical advice, it has decreased falls.
Keywords: Duchenne’s muscular dystrophy, Rheumatology, Bamako
11
Blake, Derek J., Andrew Weir, Sarah E. Newey, and Kay E. Davies. "Function and Genetics of Dystrophin and Dystrophin-Related Proteins in Muscle." Physiological Reviews 82, no. 2 (April 1, 2002): 291–329. http://dx.doi.org/10.1152/physrev.00028.2001.
Full textAbstract:
The X-linked muscle-wasting disease Duchenne muscular dystrophy is caused by mutations in the gene encoding dystrophin. There is currently no effective treatment for the disease; however, the complex molecular pathology of this disorder is now being unravelled. Dystrophin is located at the muscle sarcolemma in a membrane-spanning protein complex that connects the cytoskeleton to the basal lamina. Mutations in many components of the dystrophin protein complex cause other forms of autosomally inherited muscular dystrophy, indicating the importance of this complex in normal muscle function. Although the precise function of dystrophin is unknown, the lack of protein causes membrane destabilization and the activation of multiple pathophysiological processes, many of which converge on alterations in intracellular calcium handling. Dystrophin is also the prototype of a family of dystrophin-related proteins, many of which are found in muscle. This family includes utrophin and α-dystrobrevin, which are involved in the maintenance of the neuromuscular junction architecture and in muscle homeostasis. New insights into the pathophysiology of dystrophic muscle, the identification of compensating proteins, and the discovery of new binding partners are paving the way for novel therapeutic strategies to treat this fatal muscle disease. This review discusses the role of the dystrophin complex and protein family in muscle and describes the physiological processes that are affected in Duchenne muscular dystrophy.
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Carberry, Steven, Margit Zweyer, Dieter Swandulla, and Kay Ohlendieck. "Profiling of Age-Related Changes in theTibialis AnteriorMuscle Proteome of the mdx Mouse Model of Dystrophinopathy." Journal of Biomedicine and Biotechnology 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/691641.
Full textAbstract:
X-linked muscular dystrophy is a highly progressive disease of childhood and characterized by primary genetic abnormalities in the dystrophin gene. Senescent mdx specimens were used for a large-scale survey of potential age-related alterations in the dystrophic phenotype, because the established mdx animal model of dystrophinopathy exhibits progressive deterioration of muscle tissue with age. Since the mdxtibialis anteriormuscle is a frequently used model system in muscular dystrophy research, we employed this particular muscle to determine global changes in the dystrophic skeletal muscle proteome. The comparison of mdx mice aged 8 weeks versus 22 months by mass-spectrometry-based proteomics revealed altered expression levels in 8 distinct protein species. Increased levels were shown for carbonic anhydrase, aldolase, and electron transferring flavoprotein, while the expressions of pyruvate kinase, myosin, tropomyosin, and the small heat shock protein Hsp27 were found to be reduced in aged muscle. Immunoblotting confirmed age-dependent changes in the density of key muscle proteins in mdx muscle. Thus, segmental necrosis in mdxtibialis anteriormuscle appears to trigger age-related protein perturbations due to dystrophin deficiency. The identification of novel indicators of progressive muscular dystrophy might be useful for the establishment of a muscle subtype-specific biomarker signature of dystrophinopathy.
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Niranjan, Nandita, Satvik Mareedu, Yimin Tian, Kasun Kodippili, Nadezhda Fefelova, Antanina Voit, Lai-Hua Xie, Dongsheng Duan, and Gopal J. Babu. "Sarcolipin overexpression impairs myogenic differentiation in Duchenne muscular dystrophy." American Journal of Physiology-Cell Physiology 317, no. 4 (October 1, 2019): C813—C824. http://dx.doi.org/10.1152/ajpcell.00146.2019.
Full textAbstract:
Reduction in the expression of sarcolipin (SLN), an inhibitor of sarco(endo)plasmic reticulum (SR) Ca2+-ATPase (SERCA), ameliorates severe muscular dystrophy in mice. However, the mechanism by which SLN inhibition improves muscle structure remains unclear. Here, we describe the previously unknown function of SLN in muscle differentiation in Duchenne muscular dystrophy (DMD). Overexpression of SLN in C2C12 resulted in decreased SERCA pump activity, reduced SR Ca2+ load, and increased intracellular Ca2+ ([Formula: see text]) concentration. In addition, SLN overexpression resulted in altered expression of myogenic markers and poor myogenic differentiation. In dystrophin-deficient dog myoblasts and myotubes, SLN expression was significantly high and associated with defective [Formula: see text] cycling. The dystrophic dog myotubes were less branched and associated with decreased autophagy and increased expression of mitochondrial fusion and fission proteins. Reduction in SLN expression restored these changes and enhanced dystrophic dog myoblast fusion during differentiation. In summary, our data suggest that SLN upregulation is an intrinsic secondary change in dystrophin-deficient myoblasts and could account for the [Formula: see text] mishandling, which subsequently contributes to poor myogenic differentiation. Accordingly, reducing SLN expression can improve the [Formula: see text] cycling and differentiation of dystrophic myoblasts. These findings provide cellular-level supports for targeting SLN expression as a therapeutic strategy for DMD.
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Spaulding, Hannah R., Tiffany Quindry, Kayleen Hammer, John C. Quindry, and Joshua T. Selsby. "Nutraceutical and pharmaceutical cocktails did not improve muscle function or reduce histological damage in D2-mdx mice." Journal of Applied Physiology 127, no. 4 (October 1, 2019): 1058–66. http://dx.doi.org/10.1152/japplphysiol.00162.2019.
Full textAbstract:
Progressive muscle injury and weakness are hallmarks of Duchenne muscular dystrophy. We showed previously that quercetin (Q) partially protected dystrophic limb muscles from disease-related injury. As quercetin activates PGC-1α through Sirtuin-1, an NAD+-dependent deacetylase, the depleted NAD+ in dystrophic skeletal muscle may limit quercetin efficacy; hence, supplementation with the NAD+ donor, nicotinamide riboside (NR), may facilitate quercetin efficacy. Lisinopril (Lis) protects skeletal muscle and improves cardiac function in dystrophin-deficient mice; therefore, it was included in this study to evaluate the effects of lisinopril used with quercetin and NR. Our purpose was to determine the extent to which Q, NR, and Lis decreased dystrophic injury. We hypothesized that Q, NR, or Lis alone would improve muscle function and decrease histological injury and when used in combination would have additive effects. Muscle function of 11-mo-old DBA (healthy), D2-mdx (dystrophin-deficient), and D2-mdx mice was assessed after treatment with Q, NR, and/or Lis for 7 mo. To mimic typical pharmacology of patients with Duchenne muscular dystrophy, a group was treated with prednisolone (Pred) in combination with Q, NR, and Lis. At 11 mo of age, dystrophin deficiency decreased specific tension and tetanic force in the soleus and extensor digitorum longus muscles and was not corrected by any treatment. Dystrophic muscle was more sensitive to contraction-induced injury, which was partially offset in the QNRLisPred group, whereas fatigue was similar between all groups. Treatments did not decrease histological damage. These data suggest that treatment with Q, NR, Lis, and Pred failed to adequately maintain dystrophic limb muscle function or decrease histological damage. NEW & NOTEWORTHY Despite a compelling rationale and previous evidence to the contrary in short-term investigations, quercetin, nicotinamide riboside, or Lisinopril, alone or in combination, failed to restore muscle function or decrease histological injury in dystrophic limb muscle from D2-mdx mice after long-term administration. Importantly, we also found that in the D2-mdx model, an emerging and relatively understudied model of Duchenne muscular dystrophy dystrophin deficiency caused profound muscle dysfunction and histopathology in skeletal muscle.
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Vieira, Natassia M., Janelle M. Spinazzola, Matthew S. Alexander, Yuri B. Moreira, Genri Kawahara, Devin E. Gibbs, Lillian C. Mead, Sergio Verjovski-Almeida, Mayana Zatz, and Louis M. Kunkel. "Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy." Proceedings of the National Academy of Sciences 114, no. 23 (May 22, 2017): 6080–85. http://dx.doi.org/10.1073/pnas.1703556114.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by X-linked inherited mutations in the DYSTROPHIN (DMD) gene. Absence of dystrophin protein from the sarcolemma causes severe muscle degeneration, fibrosis, and inflammation, ultimately leading to cardiorespiratory failure and premature death. Although there are several promising strategies under investigation to restore dystrophin protein expression, there is currently no cure for DMD, and identification of genetic modifiers as potential targets represents an alternative therapeutic strategy. In a Brazilian golden retriever muscular dystrophy (GRMD) dog colony, two related dogs demonstrated strikingly mild dystrophic phenotypes compared with those typically observed in severely affected GRMD dogs despite lacking dystrophin. Microarray analysis of these “escaper” dogs revealed reduced expression of phosphatidylinositol transfer protein-α (PITPNA) in escaper versus severely affected GRMD dogs. Based on these findings, we decided to pursue investigation of modulation of PITPNA expression on dystrophic pathology in GRMD dogs, dystrophin-deficient sapje zebrafish, and human DMD myogenic cells. In GRMD dogs, decreased expression of Pitpna was associated with increased phosphorylated Akt (pAkt) expression and decreased PTEN levels. PITPNA knockdown by injection of morpholino oligonucleotides in sapje zebrafish also increased pAkt, rescued the abnormal muscle phenotype, and improved long-term sapje mutant survival. In DMD myotubes, PITPNA knockdown by lentiviral shRNA increased pAkt and increased myoblast fusion index. Overall, our findings suggest PIPTNA as a disease modifier that accords benefits to the abnormal signaling, morphology, and function of dystrophic skeletal muscle, and may be a target for DMD and related neuromuscular diseases.
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Spiro, Alfred J. "Muscular Dystrophy." Pediatrics In Review 16, no. 11 (November 1, 1995): 437. http://dx.doi.org/10.1542/pir.16.11.437.
Full textAbstract:
Several varieties of muscular dystrophy can be distinguished on clinical, genetic, morphologic, and physiologic grounds. The classification includes Duchenne and Becker muscular dystrophies, both X-linked disorders; facioscapulohumeral muscular dystrophy, which is autosomal dominant; and limb-girdle muscular dystrophy, generally autosomal recessive. Duchenne muscular dystrophy (DMD), which occurs in approximately 1 in 3500 live male births, has no recognizable signs or symptoms at birth. However, markedly elevated serum creatine kinase always is demonstrable, even at birth. A molecular diagnosis can be made at any time in the patient's lifetime by demonstrating the defect in the dystrophin gene, the absence of dystrophin in a muscle biopsy, and the characteristic morphologic abnormalities.
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Koenig, Xaver, Janine Ebner, and Karlheinz Hilber. "Voltage-Dependent Sarcolemmal Ion Channel Abnormalities in the Dystrophin-Deficient Heart." International Journal of Molecular Sciences 19, no. 11 (October 23, 2018): 3296. http://dx.doi.org/10.3390/ijms19113296.
Full textAbstract:
Mutations in the gene encoding for the intracellular protein dystrophin cause severe forms of muscular dystrophy. These so-called dystrophinopathies are characterized by skeletal muscle weakness and degeneration. Dystrophin deficiency also gives rise to considerable complications in the heart, including cardiomyopathy development and arrhythmias. The current understanding of the pathomechanisms in the dystrophic heart is limited, but there is growing evidence that dysfunctional voltage-dependent ion channels in dystrophin-deficient cardiomyocytes play a significant role. Herein, we summarize the current knowledge about abnormalities in voltage-dependent sarcolemmal ion channel properties in the dystrophic heart, and discuss the potentially underlying mechanisms, as well as their pathophysiological relevance.
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Gargan, Stephen, Paul Dowling, Margit Zweyer, Michael Henry, Paula Meleady, Dieter Swandulla, and Kay Ohlendieck. "Proteomic Identification of Markers of Membrane Repair, Regeneration and Fibrosis in the Aged and Dystrophic Diaphragm." Life 12, no. 11 (October 22, 2022): 1679. http://dx.doi.org/10.3390/life12111679.
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Deficiency in the membrane cytoskeletal protein dystrophin is the underlying cause of the progressive muscle wasting disease named Duchenne muscular dystrophy. In order to detect novel disease marker candidates and confirm the complexity of the pathobiochemical signature of dystrophinopathy, mass spectrometric screening approaches represent ideal tools for comprehensive biomarker discovery studies. In this report, we describe the comparative proteomic analysis of young versus aged diaphragm muscles from wild type versus the dystrophic mdx-4cv mouse model of X-linked muscular dystrophy. The survey confirmed the drastic reduction of the dystrophin-glycoprotein complex in the mdx-4cv diaphragm muscle and concomitant age-dependent changes in key markers of muscular dystrophy, including proteins involved in cytoskeletal organization, metabolite transportation, the cellular stress response and excitation-contraction coupling. Importantly, proteomic markers of the regulation of membrane repair, tissue regeneration and reactive myofibrosis were detected by mass spectrometry and changes in key proteins were confirmed by immunoblotting. Potential disease marker candidates include various isoforms of annexin, the matricellular protein periostin and a large number of collagens. Alterations in these proteoforms can be useful to evaluate adaptive, compensatory and pathobiochemical changes in the intracellular cytoskeleton, myofiber membrane integrity and the extracellular matrix in dystrophin-deficient skeletal muscle tissues.
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Gambino, Anya N., Pamela J. Mouser, G. Diane Shelton, and Nena J. Winand. "Emergent Presentation of a Cat with Dystrophin-Deficient Muscular Dystrophy." Journal of the American Animal Hospital Association 50, no. 2 (March 1, 2014): 130–35. http://dx.doi.org/10.5326/jaaha-ms-5973.
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This report describes a case of feline dystrophin-deficient muscular dystrophy (DDMD) with an atypical clinical presentation. A novel gene mutation is reported to be responsible for dystrophin-deficient hypertrophic muscular dystrophy. In an emergency setting, clinicians should be aware of muscular dystrophy in young cats and the importance of elevated creatine kinase (CK) activity. Muscular dystrophy is rare but can present both a diagnostic and therapeutic challenge in an emergency setting. Patients with muscular dystrophy have a progressive disease with no specific treatment and have an increased risk for death during their hospital stay.
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Wehling, Michelle, Melissa J. Spencer, and James G. Tidball. "A nitric oxide synthase transgene ameliorates muscular dystrophy in mdx mice." Journal of Cell Biology 155, no. 1 (October 1, 2001): 123–32. http://dx.doi.org/10.1083/jcb.200105110.
Full textAbstract:
Dystrophin-deficient muscles experience large reductions in expression of nitric oxide synthase (NOS), which suggests that NO deficiency may influence the dystrophic pathology. Because NO can function as an antiinflammatory and cytoprotective molecule, we propose that the loss of NOS from dystrophic muscle exacerbates muscle inflammation and fiber damage by inflammatory cells. Analysis of transgenic mdx mice that were null mutants for dystrophin, but expressed normal levels of NO in muscle, showed that the normalization of NO production caused large reductions in macrophage concentrations in the mdx muscle. Expression of the NOS transgene in mdx muscle also prevented the majority of muscle membrane injury that is detectable in vivo, and resulted in large decreases in serum creatine kinase concentrations. Furthermore, our data show that mdx muscle macrophages are cytolytic at concentrations that occur in dystrophic, NOS-deficient muscle, but are not cytolytic at concentrations that occur in dystrophic mice that express the NOS transgene in muscle. Finally, our data show that antibody depletions of macrophages from mdx mice cause significant reductions in muscle membrane injury. Together, these findings indicate that macrophages promote injury of dystrophin-deficient muscle, and the loss of normal levels of NO production by dystrophic muscle exacerbates inflammation and membrane injury in muscular dystrophy.
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Hilton, Stephanie, Matthias Christen, Thomas Bilzer, Vidhya Jagannathan, Tosso Leeb, and Urs Giger. "Dystrophin (DMD) Missense Variant in Cats with Becker-Type Muscular Dystrophy." International Journal of Molecular Sciences 24, no. 4 (February 6, 2023): 3192. http://dx.doi.org/10.3390/ijms24043192.
Full textAbstract:
Muscular dystrophy due to dystrophin deficiency in humans is phenotypically divided into a severe Duchenne and milder Becker type. Dystrophin deficiency has also been described in a few animal species, and few DMD gene variants have been identified in animals. Here, we characterize the clinical, histopathological, and molecular genetic aspects of a family of Maine Coon crossbred cats with clinically mild and slowly progressive muscular dystrophy. Two young adult male littermate cats exhibited abnormal gait and muscular hypertrophy with macroglossia. Serum creatine kinase activities were highly increased. Histopathologically, dystrophic skeletal muscle exhibited marked structural changes including atrophic, hypertrophic, and necrotic muscle fibers. Immunohistochemistry showed irregularly reduced expression of dystrophin but the staining of other muscle proteins such as β- and γ-sarcoglycans as well as desmin was also diminished. Whole genome sequencing of one affected cat and genotyping of the littermate found both to be hemizygous mutant at a single DMD missense variant (c.4186C>T). No other protein-changing variants in candidate genes for muscular dystrophy were detected. In addition, one clinically healthy male littermate was hemizygous wildtype, while the queen and one female littermate were clinically healthy, but heterozygous. The predicted amino acid exchange (p.His1396Tyr) resides in a conserved central rod spectrin domain of dystrophin. Various protein modeling programs did not predict major disruption of the dystrophin protein by this substitution, but the altered charge of the region may still affect protein function. This study represents the first genotype-to-phenotype correlation of Becker-type dystrophin deficiency in companion animals.
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Pákozdy, Á., M. Leschnik, B. Nell, U. Kolm, Z. Virányi, B. Belényi, M. Molnár, and T. Bilzer. "Myotonic dystrophy in two European grey wolves ( Canis lupus )." Acta Veterinaria Hungarica 55, no. 1 (March 1, 2007): 87–95. http://dx.doi.org/10.1556/avet.55.2007.1.9.
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Two related European Grey wolves ( Canis lupus ) with the history of muscle stiffness beginning at 2 weeks of age were examined in this study. Muscle tone and muscle mass were increased in both animals. Muscle stiffness was worsened by stress so that the animals fell into lateral recumbency. Blood chemistry revealed mildly increased serum creatine kinase activity. Abnormal potentials typical of myotonic discharges were recorded by electromyography. Cataract, first-degree atrioventricular (AV) block and inhomogeneous myocardial texture by ultrasound suggested extramuscular involvement. Myopathology demonstrated dystrophic signs in the muscle biopsy specimen. The presumptive diagnosis based on the in vivo findings was myotonic dystrophy. Immunochemistry of the striated muscles revealed focal absence of dystrophin 1 and beta-dystroglycan in both cases. Cardiac and ophthalmologic involvement suggested a disorder very similar to a human form of myotonic dystrophy. This is the first description of myotonic dystrophy in wolves.
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Mázala, Davi A. G., Robert W. Grange, and Eva R. Chin. "The role of proteases in excitation-contraction coupling failure in muscular dystrophy." American Journal of Physiology-Cell Physiology 308, no. 1 (January 1, 2015): C33—C40. http://dx.doi.org/10.1152/ajpcell.00267.2013.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is one of the most frequent types of muscular dystrophy. Alterations in intracellular calcium (Ca2+) handling are thought to contribute to the disease severity in DMD, possibly due to the activation of Ca2+-activated proteases. The purpose of this study was twofold: 1) to determine whether prolonged excitation-contraction (E-C) coupling disruption following repeated contractions is greater in animals lacking both dystrophin and utrophin ( mdx/Utr−/−) compared with mice lacking only dystrophin ( mdx); and 2) to assess whether protease inhibition can prevent E-C coupling failure following repeated tetani in these dystrophic mouse models. Excitation-contraction coupling was assessed using Fura-2 ratio, as an index of intracellular free Ca2+ concentration, in response to electrical stimulation of single muscle fibers from the flexor digitorum brevis muscle. Resting Fura-2 ratio was higher in dystrophic compared with control (Con) fibers, but peak Fura-2 ratios during stimulation were similar in dystrophic and Con fibers. One hour after a series of repeated tetani, peak Fura-2 ratios were reduced by 30 ± 5.6%, 23 ± 2%, and 36 ± 3.1% in mdx, mdx/Utr+/−, and mdx/Utr−/−, respectively, with the greatest reduction in mdx/Utr−/− fibers ( P < 0.05). Protease inhibition attenuated this decrease in peak Fura-2 ratio. These data indicate that E-C coupling impairment after repeated contractions is greatest in fibers lacking both dystrophin and utrophin and that prevention of protease activation can mitigate the prolonged E-C coupling impairment. These data further suggest that acute protease inhibition may be useful in reducing muscle weakness in DMD.
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Corrado, K., J. A. Rafael, P. L. Mills, N. M. Cole, J. A. Faulkner, K. Wang, and J. S. Chamberlain. "Transgenic mdx mice expressing dystrophin with a deletion in the actin-binding domain display a "mild Becker" phenotype." Journal of Cell Biology 134, no. 4 (August 15, 1996): 873–84. http://dx.doi.org/10.1083/jcb.134.4.873.
Full textAbstract:
The functional significance of the actin-binding domain of dystrophin, the protein lacking in patients with Duchenne muscular dystrophy, has remained elusive. Patients with deletions of this domain (domain I) typically express low levels of the truncated protein. Whether the moderate to severe phenotypes associated with such deletions result from loss of an essential function, or from reduced levels of a functional protein, is unclear. To address this question, we have generated transgenic mice that express wild-type levels of a dystrophin deleted for the majority of the actin-binding domain. The transgene derived protein lacks amino acids 45-273, removing 2 of 3 in vitro identified actin interacting sites and part of hinge 1. Examination of the effect of this deletion in mice lacking wild-type dystrophin (mdx) suggests that a functional domain I is not essential for prevention of a dystrophic phenotype. However, in contrast to deletions in the central rod domain and to full-length dystrophin, both of which are functional at only 20% of wild-type levels, proteins with a deletion in domain I must be expressed at high levels to prevent a severe dystrophy. These results are also in contrast to the severe dystrophy resulting from truncation of the COOH-terminal domain that links dystrophin to the extracellular matrix. The mild phenotype observed in mice with domain I-deletions indicates that an intact actin-binding domain is not essential, although it does contribute to an important function of dystrophin. These studies also suggest the link between dystrophin and the subsarcolemmal cytoskeleton involves more than a simple attachment of domain I to actin filaments.
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Rubi, Lena, Vaibhavkumar S. Gawali, Helmut Kubista, Hannes Todt, Karlheinz Hilber, and Xaver Koenig. "Proper Voltage-Dependent Ion Channel Function in Dysferlin-Deficient Cardiomyocytes." Cellular Physiology and Biochemistry 36, no. 3 (2015): 1049–58. http://dx.doi.org/10.1159/000430278.
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Background/Aims: Dysferlin plays a decisive role in calcium-dependent membrane repair in myocytes. Mutations in the encoding DYSF gene cause a number of myopathies, e.g. limb-girdle muscular dystrophy type 2B (LGMD2B). Besides skeletal muscle degenerative processes, dysferlin deficiency is also associated with cardiac complications. Thus, both LGMD2B patients and dysferlin-deficient mice develop a dilated cardiomyopathy. We and others have recently reported that dystrophin-deficient ventricular cardiomyocytes from mouse models of Duchenne muscular dystrophy show significant abnormalities in voltage-dependent ion channels, which may contribute to the pathophysiology in dystrophic cardiomyopathy. The aim of the present study was to investigate if dysferlin, like dystrophin, is a regulator of cardiac ion channels. Methods and Results: By using the whole cell patch-clamp technique, we compared the properties of voltage-dependent calcium and sodium channels, as well as action potentials in ventricular cardiomyocytes isolated from the hearts of normal and dysferlin-deficient (dysf) mice. In contrast to dystrophin deficiency, the lack of dysferlin did not impair the ion channel properties and left action potential parameters unaltered. In connection with normal ECGs in dysf mice these results suggest that dysferlin deficiency does not perturb cardiac electrophysiology. Conclusion: Our study demonstrates that dysferlin does not regulate cardiac voltage-dependent ion channels, and implies that abnormalities in cardiac ion channels are not a universal characteristic of all muscular dystrophy types.
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Yeadon, J. E., H. Lin, S. M. Dyer, and S. J. Burden. "Dystrophin is a component of the subsynaptic membrane." Journal of Cell Biology 115, no. 4 (November 15, 1991): 1069–76. http://dx.doi.org/10.1083/jcb.115.4.1069.
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A subsynaptic protein of Mr approximately 300 kD is a major component of Torpedo electric organ postsynaptic membranes and copurifies with the AChR and the 43-kD subsynaptic protein. mAbs against this protein react with neuromuscular synapses in higher vertebrates, but not at synapses in dystrophic muscle. The Torpedo 300-kD protein comigrates in SDS-PAGE with murine dystrophin and reacts with antibodies against murine dystrophin. The sequence of a partial cDNA isolated by screening an expression library with mAbs against the Torpedo 300-kD protein shows striking homology to mammalian dystrophin, and in particular to the b isoform of dystrophin. These results indicate that dystrophin is a component of the postsynaptic membrane at neuromuscular synapses and raise the possibility that loss of dystrophin from synapses in dystrophic muscle may have consequences that contribute to muscular dystrophy.
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Watchko, Jon F., Terrence L. O'Day, and Eric P. Hoffman. "Functional characteristics of dystrophic skeletal muscle: insights from animal models." Journal of Applied Physiology 93, no. 2 (August 1, 2002): 407–17. http://dx.doi.org/10.1152/japplphysiol.01242.2001.
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Muscular dystrophies are a clinically and genetically heterogeneous group of disorders that show myofiber degeneration and regeneration. Identification of animal models of muscular dystrophy has been instrumental in research on the pathogenesis, pathophysiology, and treatment of these disorders. We review our understanding of the functional status of dystrophic skeletal muscle from selected animal models with a focus on 1) the mdx mouse model of Duchenne muscular dystrophy, 2) the Bio 14.6 δ-sarcoglycan-deficient hamster model of limb-girdle muscular dystrophy, and 3) transgenic null mutant murine lines of sarcoglycan (α, β, δ, and γ) deficiencies. Although biochemical data from these models suggest that the dystrophin-sarcoglycan-dystroglycan-laminin network is critical for structural integrity of the myofiber plasma membrane, emerging studies of muscle physiology suggest a more complex picture, with specific functional deficits varying considerably from muscle to muscle and model to model. It is likely that changes in muscle structure and function, downstream of the specific, primary biochemical deficiency, may alter muscle contractile properties.
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Gumerson, Jessica D., and Daniel E. Michele. "The Dystrophin-Glycoprotein Complex in the Prevention of Muscle Damage." Journal of Biomedicine and Biotechnology 2011 (2011): 1–13. http://dx.doi.org/10.1155/2011/210797.
Full textAbstract:
Muscular dystrophies are genetically diverse but share common phenotypic features of muscle weakness, degeneration, and progressive decline in muscle function. Previous work has focused on understanding how disruptions in the dystrophin-glycoprotein complex result in muscular dystrophy, supporting a hypothesis that the muscle sarcolemma is fragile and susceptible to contraction-induced injury in multiple forms of dystrophy. Although benign in healthy muscle, contractions in dystrophic muscle may contribute to a higher degree of muscle damage which eventually overwhelms muscle regeneration capacity. While increased susceptibility of muscle to mechanical injury is thought to be an important contributor to disease pathology, it is becoming clear that not all DGC-associated diseases share this supposed hallmark feature. This paper outlines experimental support for a function of the DGC in preventing muscle damage and examines the evidence that supports novel functions for this complex in muscle that when impaired, may contribute to the pathogenesis of muscular dystrophy.
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Dosani, Minaj, and Harish Kumar Singhal. "An Ayurvedic Approach in Muscular Dystrophy in Children." International Journal of Health Sciences and Research 14, no. 3 (March 9, 2024): 105–16. http://dx.doi.org/10.52403/ijhsr.20240318.
Full textAbstract:
Duchenne muscular dystrophy stands out as the most prevalent and severe form of childhood muscular dystrophy, impacting approximately one in every 5200 male births. It results from dystrophin deficiency, a condition inherited through X-linked recessive traits due to a missing or altered dystrophin protein encoded by the DMD gene located on chromosome Xp21. Unfortunately, this myopathy is currently incurable, often leading to mortality between the ages of 20-25. The primary pharmaceutical intervention for Duchenne muscular dystrophy involves corticosteroids, though they come with long-term negative consequences.In the realm of Ayurveda, Duchenne muscular dystrophy falls under the classification of Medomamsa dushti, attributed to Vata doshas and stemming from Bheejabagahaavyava dushti. Ayurvedic strategies for management emphasize the promotion of regeneration in neuromuscular illnesses, employing a combination of Ayurvedic oral drugs and Panchakarma therapies. Key words: DMD, Dystrophin, Muscular Dystrophy, Medovaha Srotodushti
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Beckers, Evy, Ine Cornelis, Sofie F. M. Bhatti, Pascale Smets, G. Diane Shelton, Ling T. Guo, Luc Peelman, and Bart J. G. Broeckx. "A Nonsense Variant in the DMD Gene Causes X-Linked Muscular Dystrophy in the Maine Coon Cat." Animals 12, no. 21 (October 25, 2022): 2928. http://dx.doi.org/10.3390/ani12212928.
Full textAbstract:
(1) Feline dystrophin-deficient muscular dystrophy (ddMD) is a fatal disease characterized by progressive weakness and degeneration of skeletal muscles and is caused by variants in the DMD gene. To date, only two feline causal variants have been identified. This study reports two cases of male Maine coon siblings that presented with muscular hypertrophy, growth retardation, weight loss, and vomiting. (2) Both cats were clinically examined and histopathology and immunofluorescent staining of the affected muscle was performed. DMD mRNA was sequenced to identify putative causal variants. (3) Both cats showed a significant increase in serum creatine kinase activity. Electromyography and histopathological examination of the muscle samples revealed abnormalities consistent with a dystrophic phenotype. Immunohistochemical testing revealed the absence of dystrophin, confirming the diagnosis of dystrophin-deficient muscular dystrophy. mRNA sequencing revealed a nonsense variant in exon 11 of the feline DMD gene, NC_058386.1 (XM_045050794.1): c.1180C>T (p.(Arg394*)), which results in the loss of the majority of the dystrophin protein. Perfect X-linked segregation of the variant was established in the pedigree. (4) ddMD was described for the first time in the Maine coon and the c.1180C>T variant was confirmed as the causal variant.
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Lewis, Caroline, Harald Jockusch, and Kay Ohlendieck. "Proteomic Profiling of the Dystrophin-Deficient MDX Heart Reveals Drastically Altered Levels of Key Metabolic and Contractile Proteins." Journal of Biomedicine and Biotechnology 2010 (2010): 1–20. http://dx.doi.org/10.1155/2010/648501.
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Although Duchenne muscular dystrophy is primarily classified as a neuromuscular disease, cardiac complications play an important role in the course of this X-linked inherited disorder. The pathobiochemical steps causing a progressive decline in the dystrophic heart are not well understood. We therefore carried out a fluorescence difference in-gel electrophoretic analysis of 9-month-old dystrophin-deficient versus age-matched normal heart, using the established MDX mouse model of muscular dystrophy-related cardiomyopathy. Out of 2,509 detectable protein spots, 79 2D-spots showed a drastic differential expression pattern, with the concentration of 3 proteins being increased, including nucleoside diphosphate kinase and lamin-A/C, and of 26 protein species being decreased, including ATP synthase, fatty acid binding-protein, isocitrate dehydrogenase, NADH dehydrogenase, porin, peroxiredoxin, adenylate kinase, tropomyosin, actin, and myosin light chains. Hence, the lack of cardiac dystrophin appears to trigger a generally perturbed protein expression pattern in the MDX heart, affecting especially energy metabolism and contractile proteins.
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Kikuchi, Tateki. "Caveolin-3: A Causative Process of Chicken Muscular Dystrophy." Biomolecules 10, no. 9 (August 20, 2020): 1206. http://dx.doi.org/10.3390/biom10091206.
Full textAbstract:
The etiology of chicken muscular dystrophy is the synthesis of aberrant WW domain containing E3 ubiquitin-protein ligase 1 (WWP1) protein made by a missense mutation of WWP1 gene. The β-dystroglycan that confers stability to sarcolemma was identified as a substrate of WWP protein, which induces the next molecular collapse. The aberrant WWP1 increases the ubiquitin ligase-mediated ubiquitination following severe degradation of sarcolemmal and cytoplasmic β-dystroglycan, and an erased β-dystroglycan in dystrophic αW fibers will lead to molecular imperfection of the dystrophin-glycoprotein complex (DGC). The DGC is a core protein of costamere that is an essential part of force transduction and protects the muscle fibers from contraction-induced damage. Caveolin-3 (Cav-3) and dystrophin bind competitively to the same site of β-dystroglycan, and excessive Cav-3 on sarcolemma will block the interaction of dystrophin with β-dystroglycan, which is another reason for the disruption of the DGC. It is known that fast-twitch glycolytic fibers are more sensitive and vulnerable to contraction-induced small tears than slow-twitch oxidative fibers under a variety of diseased conditions. Accordingly, the fast glycolytic αW fibers must be easy with rapid damage of sarcolemma corruption seen in chicken muscular dystrophy, but the slow oxidative fibers are able to escape from these damages.
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Echigoya, Yusuke, Akinori Nakamura, Tetsuya Nagata, Nobuyuki Urasawa, Kenji Rowel Q. Lim, Nhu Trieu, Dharminder Panesar, et al. "Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy." Proceedings of the National Academy of Sciences 114, no. 16 (April 3, 2017): 4213–18. http://dx.doi.org/10.1073/pnas.1613203114.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising therapeutic options, yet PMOs have shown very little efficacy in cardiac muscle. To increase therapeutic potency in cardiac muscle, we tested a next-generation morpholino: arginine-rich, cell-penetrating peptide-conjugated PMOs (PPMOs) in the canine X-linked muscular dystrophy in Japan (CXMDJ) dog model of DMD. A PPMO cocktail designed to skip dystrophin exons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMDJ dogs. Intravenous injections with PPMOs restored dystrophin expression in the myocardium and cardiac Purkinje fibers, as well as skeletal muscles. Vacuole degeneration of cardiac Purkinje fibers, as seen in DMD patients, was ameliorated in PPMO-treated dogs. Although symptoms and functions in skeletal muscle were not ameliorated by i.v. treatment, electrocardiogram abnormalities (increased Q-amplitude and Q/R ratio) were improved in CXMDJ dogs after intracoronary or i.v. administration. No obvious evidence of toxicity was found in blood tests throughout the monitoring period of one or four systemic treatments with the PPMO cocktail (12 mg/kg/injection). The present study reports the rescue of dystrophin expression and recovery of the conduction system in the heart of dystrophic dogs by PPMO-mediated multiexon skipping. We demonstrate that rescued dystrophin expression in the Purkinje fibers leads to the improvement/prevention of cardiac conduction abnormalities in the dystrophic heart.
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González-Jamett, Arlek, Walter Vásquez, Gabriela Cifuentes-Riveros, Rafaela Martínez-Pando, Juan C. Sáez, and Ana M. Cárdenas. "Oxidative Stress, Inflammation and Connexin Hemichannels in Muscular Dystrophies." Biomedicines 10, no. 2 (February 21, 2022): 507. http://dx.doi.org/10.3390/biomedicines10020507.
Full textAbstract:
Muscular dystrophies (MDs) are a heterogeneous group of congenital neuromuscular disorders whose clinical signs include myalgia, skeletal muscle weakness, hypotonia, and atrophy that leads to progressive muscle disability and loss of ambulation. MDs can also affect cardiac and respiratory muscles, impairing life-expectancy. MDs in clude Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy and limb-girdle muscular dystrophy. These and other MDs are caused by mutations in genes that encode proteins responsible for the structure and function of skeletal muscles, such as components of the dystrophin-glycoprotein-complex that connect the sarcomeric-actin with the extracellular matrix, allowing contractile force transmission and providing stability during muscle contraction. Consequently, in dystrophic conditions in which such proteins are affected, muscle integrity is disrupted, leading to local inflammatory responses, oxidative stress, Ca2+-dyshomeostasis and muscle degeneration. In this scenario, dysregulation of connexin hemichannels seem to be an early disruptor of the homeostasis that further plays a relevant role in these processes. The interaction between all these elements constitutes a positive feedback loop that contributes to the worsening of the diseases. Thus, we discuss here the interplay between inflammation, oxidative stress and connexin hemichannels in the progression of MDs and their potential as therapeutic targets.
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Krupnick, Alexander S., Jianliang Zhu, Taitan Nguyen, Daniel Kreisel, Keki R. Balsara, Edward B. Lankford, Charles C. Clark, Sanford Levine, Hansell H. Stedman, and Joseph B. Shrager. "Inspiratory loading does not accelerate dystrophy inmdx mouse diaphragm: implications for regenerative therapy." Journal of Applied Physiology 94, no. 2 (February 1, 2003): 411–19. http://dx.doi.org/10.1152/japplphysiol.00689.2002.
Full textAbstract:
Since the finding that the mdx mouse diaphragm, in contrast to limb muscles, undergoes progressive degeneration analogous to that seen in Duchenne muscular dystrophy, the relationship between the workload on a muscle and the pathogenesis of dystrophy has remained controversial. We increased the work performed by the mdx mouse diaphragm in vivo by tracheal banding and evaluated the progression of dystrophic changes in that muscle. Despite the establishment of dramatically increased respiratory workload and accelerated myofiber damage documented by Evans blue dye, no change in the pace of progression of dystrophy was seen in banded animals vs. unbanded, sham-operated controls. At the completion of the study, more centrally nucleated fibers were evident in the diaphragms of banded mdx mice than in sham-operated mdx controls, indicating that myofiber regeneration increases to meet the demands of the work-induced damage. These data suggest that there is untapped regenerative capacity in dystrophin-deficient muscle and validates experimental efforts aimed at augmenting regeneration within skeletal muscle as a therapeutic strategy in the treatment of dystrophinopathies.
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Peter, Angela K., Jamie L. Marshall, and Rachelle H. Crosbie. "Sarcospan reduces dystrophic pathology: stabilization of the utrophin–glycoprotein complex." Journal of Cell Biology 183, no. 3 (November 3, 2008): 419–27. http://dx.doi.org/10.1083/jcb.200808027.
Full textAbstract:
Mutations in the dystrophin gene cause Duchenne muscular dystrophy and result in the loss of dystrophin and the entire dystrophin–glycoprotein complex (DGC) from the sarcolemma. We show that sarcospan (SSPN), a unique tetraspanin-like component of the DGC, ameliorates muscular dystrophy in dystrophin-deficient mdx mice. SSPN stabilizes the sarcolemma by increasing levels of the utrophin–glycoprotein complex (UGC) at the extrasynaptic membrane to compensate for the loss of dystrophin. Utrophin is normally restricted to the neuromuscular junction, where it replaces dystrophin to form a functionally analogous complex. SSPN directly interacts with the UGC and functions to stabilize utrophin protein without increasing utrophin transcription. These findings reveal the importance of protein stability in the prevention of muscular dystrophy and may impact the future design of therapeutics for muscular dystrophies.
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lordlin, Dr R. T. J. R. Lordlin, and Dr Franklin Shaju. "PHYSIO IN DUCHENNE MUSCULAR DYSTROPHY (DMD)." IDC International Journal 8, no. 4 (October 10, 2021): 1–4. http://dx.doi.org/10.47211/idcij.2021.v08i04.001.
Full textAbstract:
Duchenne muscular dystrophy is the most common and severe form of muscular dystrophy and is caused by mutations in the dystrophin gene. Dystrophin, together with several other protein components, is part of a complex known as the dystrophin glycoprotein complex (DGC). The DGC plays an essential role in maintaining the structural integrity of the muscle cell membrane by providing a link between the extracellular matrix and the cytoskeleton
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Saotome, Masao, Yuji Yoshitomi, Shunichi Kojima, and Morio Kuramochi. "Dilated Cardiomyopathy of Becker-Type Muscular Dystrophy with Exon 4 Deletion." Angiology 52, no. 5 (May 2001): 343–47. http://dx.doi.org/10.1177/000331970105200508.
Full textAbstract:
The authors report a 47-year-old man with Becker-type muscular dystrophy presenting with dilated cardiomyopathy. Left ventriculography showed diffuse severe hypokinesia: left ventric ular end-diastolic volume index 193 mL/m2, left ventricular end-systolic volume index 143 mL/m 2, and left ventricular ejection fraction 26%. Skeletal muscle biopsy demonstrated a dystrophic process. Genetic analysis revealed a deletion of exon 4. There was a difference in immunos taining pattern between skeletal muscles and cardiac muscles. Severe cardiac dysfunction in this case may be associated with the damage in dystrophin-deficient fibers.
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Joseph, Josiane, Dong Cho, and Jason Doles. "Metabolomic Analyses Reveal Extensive Progenitor Cell Deficiencies in a Mouse Model of Duchenne Muscular Dystrophy." Metabolites 8, no. 4 (October 3, 2018): 61. http://dx.doi.org/10.3390/metabo8040061.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is a musculoskeletal disorder that causes severe morbidity and reduced lifespan. Individuals with DMD have an X-linked mutation that impairs their ability to produce functional dystrophin protein in muscle. No cure exists for this disease and the few therapies that are available do not dramatically delay disease progression. Thus, there is a need to better understand the mechanisms underlying DMD which may ultimately lead to improved treatment options. The muscular dystrophy (MDX) mouse model is frequently used to explore DMD disease traits. Though some studies of metabolism in dystrophic mice exist, few have characterized metabolic profiles of supporting cells in the diseased environment. Using nontargeted metabolomics we characterized metabolic alterations in muscle satellite cells (SCs) and serum of MDX mice. Additionally, live-cell imaging revealed MDX-derived adipose progenitor cell (APC) defects. Finally, metabolomic studies revealed a striking elevation of acylcarnitines in MDX APCs, which we show can inhibit APC proliferation. Together, these studies highlight widespread metabolic alterations in multiple progenitor cell types and serum from MDX mice and implicate dystrophy-associated metabolite imbalances in APCs as a potential contributor to adipose tissue disequilibrium in DMD.
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Wells, Dominic J., Aurora Ferrer, and Kim E. Wells. "Immunological hurdles in the path to gene therapy for Duchenne muscular dystrophy." Expert Reviews in Molecular Medicine 4, no. 23 (November 4, 2002): 1–23. http://dx.doi.org/10.1017/s146239940200515x.
Full textAbstract:
Patients with Duchenne muscular dystrophy (DMD), an X-linked lethal muscle-wasting disease, have abnormal expression of the protein dystrophin within their muscle fibres. In the mdx mouse model of this condition, both germline and neonatal somatic gene transfers of dystrophin cDNAs have demonstrated the potential of gene therapy in treating DMD. However, in many DMD patients, there appears to be no dystrophin expression when muscle biopsies are immunostained or western blots are performed. This raises the possibility that the expression of dystrophin following gene transfer might trigger a destructive immune response against this ‘neoantigen’. Immune responses can also be generated against the gene transfer vector used to transfect the dystrophic muscle, and the combined immune response could further damage the already inflamed muscle. These problems are now beginning to be investigated in immunocompetent mdx mice. Although much work remains to be done, there are promising indications that these immune responses might not prove as much of a concern as originally envisaged.
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Chen, Yi-Wen, Po Zhao, Rehannah Borup, and Eric P. Hoffman. "Expression Profiling in the Muscular Dystrophies." Journal of Cell Biology 151, no. 6 (December 11, 2000): 1321–36. http://dx.doi.org/10.1083/jcb.151.6.1321.
Full textAbstract:
We used expression profiling to define the pathophysiological cascades involved in the progression of two muscular dystrophies with known primary biochemical defects, dystrophin deficiency (Duchenne muscular dystrophy) and α-sarcoglycan deficiency (a dystrophin-associated protein). We employed a novel protocol for expression profiling in human tissues using mixed samples of multiple patients and iterative comparisons of duplicate datasets. We found evidence for both incomplete differentiation of patient muscle, and for dedifferentiation of myofibers to alternative lineages with advancing age. One developmentally regulated gene characterized in detail, α-cardiac actin, showed abnormal persistent expression after birth in 60% of Duchenne dystrophy myofibers. The majority of myofibers (∼80%) remained strongly positive for this protein throughout the course of the disease. Other developmentally regulated genes that showed widespread overexpression in these muscular dystrophies included embryonic myosin heavy chain, versican, acetylcholine receptor α-1, secreted protein, acidic and rich in cysteine/osteonectin, and thrombospondin 4. We hypothesize that the abnormal Ca2+ influx in dystrophin- and α-sarcoglycan–deficient myofibers leads to altered developmental programming of developing and regenerating myofibers. The finding of upregulation of HLA-DR and factor XIIIa led to the novel identification of activated dendritic cell infiltration in dystrophic muscle; these cells mediate immune responses and likely induce microenvironmental changes in muscle. We also document a general metabolic crisis in dystrophic muscle, with large scale downregulation of nuclear-encoded mitochondrial gene expression. Finally, our expression profiling results show that primary genetic defects can be identified by a reduction in the corresponding RNA.
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Dubowitz, Victor, and Ronald D. Cohn. "Dystrophin and Duchenne dystrophy." Neuromuscular Disorders 25, no. 5 (May 2015): 361–62. http://dx.doi.org/10.1016/j.nmd.2015.03.013.
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Cho, Min-Sub, and Jong-Mok Lee. "Pathologically and Genetically Diagnosed Subclinical Symptomatic Duchenne Muscular Dystrophy Carrier: Broadened Spectrum of Clinical Phenotype." Journal of the Korean Neurological Association 39, no. 2 (May 1, 2021): 85–88. http://dx.doi.org/10.17340/jkna.2021.2.5.
Full textAbstract:
A 29-year-old female presented with an elevated level of serum creatine kinase without subjective weakness. Neurologic examination showed the subtle motor weakness of the right arm. Muscle biopsy showed dystrophic changes and a mosaic pattern of dystrophin expression. The diagnosis was confirmed by multiplex ligation-dependent probe amplification and whole-exome sequencing, revealing heterozygous deletion of exon 44 in the DMD gene. Here, we introduce a subclinical symptomatic Duchenne muscular dystrophy carrier, which broadens the clinical spectrum of phenotype.
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Howlett, S. E., C. R. Triggle, and T. B. Hoekman. "Effects of noradrenaline, serotonin, and selected antagonists on the vascular smooth muscle of normal and dystrophic chickens." Canadian Journal of Physiology and Pharmacology 64, no. 5 (May 1, 1986): 545–49. http://dx.doi.org/10.1139/y86-090.
Full textAbstract:
The pathogenesis of the human muscular dystrophies is unknown, and several competing hypotheses have been proposed. The vascular hypothesis states that muscle fibre necrosis occurs in dystrophy as a result of transient muscle ischemia. Although abnormalities of the vascular system may be demonstrated in dystrophy, their role in pathogenesis remains obscure. The responses to serotonin (5-HT) and noradrenaline (NA) were examined in isolated ischiatic artery preparations from normal and genetically dystrophic chickens. The tension generated in response to 5-HT was greater in arteries from normal chickens than in arteries from dystrophic chickens, whereas responses to NA were similar. Analysis of the concentration–response relationships demonstrated that the dystrophic ischiatic artery was less sensitive to 5-HT than was the normal artery, although the sensitivity to NA was similar in both vessels. The results of this study are not consistent with the view that muscle fibre necrosis in avian dystrophy is a consequence of muscle anoxia. These data do demonstrate pharmacological differences between dystrophic avian arteries and arteries from normal chickens, but their presence may represent merely the expression of dystrophy in vascular smooth muscle.
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Faqih, M. Izza Zulfana, Wahyu Tri Sudaryanto, and Salma Muazzaroh. "ACTIVE ASSISTED MOVEMENT DALAM MENJAGA KEMAMPUAN FUNGSIONAL PADA KONDISI DUCHENNE MUSCULAR DYSTROPHY." Journal of Innovation Research and Knowledge 3, no. 1 (July 1, 2023): 5047–52. http://dx.doi.org/10.53625/jirk.v3i1.5990.
Full textAbstract:
Background: Duchenne muscular dystrophy which is a recessive x-linked disorder that often affects males. Duchenne muscular dystrophy is caused by mutations in the dystrophin gene at the Xp21 locus so that dystrophin protein is not produced or dystrophin deficiency and structural abnormalities occur. Dystrophinopathies are X-linked recessive disorders affecting 1 in 5,000 to 1 in 6,000 live male births. The prevalence of DMD is less than 10 cases per 100,000 males. Objective: Physiotherapy management in this case aims to determine the benefits of providing physiotherapy interventions in the form of active assisted and passive movement and stretching in patients with Duchenne muscular dystrophy. Methods: This case report was conducted at PLDPI Surakarta by taking patients with Duchenne muscular dystrophy cases by providing physiotherapy modalities in the form of active assisted and passive movement and stretching for 3 physiotherapy sessions. Furthermore, measurements were taken with the GMFM and XOTR Scale in the first to third physiotherapy. Results: From the physiotherapy management given, it was found that functional ability and muscle strength remained unchanged and did not develop. Conclusion: Physiotherapy management in this case report is proven to be able to maintain functional ability and muscle strength in patients with Duchenne muscular dystrophy.
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Assereto, Stefania, Silvia Stringara, Federica Sotgia, Gloria Bonuccelli, Aldobrando Broccolini, Marina Pedemonte, Monica Traverso, et al. "Pharmacological rescue of the dystrophin-glycoprotein complex in Duchenne and Becker skeletal muscle explants by proteasome inhibitor treatment." American Journal of Physiology-Cell Physiology 290, no. 2 (February 2006): C577—C582. http://dx.doi.org/10.1152/ajpcell.00434.2005.
Full textAbstract:
In this report, we have developed a novel method to identify compounds that rescue the dystrophin-glycoprotein complex (DGC) in patients with Duchenne or Becker muscular dystrophy. Briefly, freshly isolated skeletal muscle biopsies (termed skeletal muscle explants) from patients with Duchenne or Becker muscular dystrophy were maintained under defined cell culture conditions for a 24-h period in the absence or presence of a specific candidate compound. Using this approach, we have demonstrated that treatment with a well-characterized proteasome inhibitor, MG-132, is sufficient to rescue the expression of dystrophin, β-dystroglycan, and α-sarcoglycan in skeletal muscle explants from patients with Duchenne or Becker muscular dystrophy. These data are consistent with our previous findings regarding systemic treatment with MG-132 in a dystrophin-deficient mdx mouse model (Bonuccelli G, Sotgia F, Schubert W, Park D, Frank PG, Woodman SE, Insabato L, Cammer M, Minetti C, and Lisanti MP. Am J Pathol 163: 1663–1675, 2003). Our present results may have important new implications for the possible pharmacological treatment of Duchenne or Becker muscular dystrophy in humans.
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Rovina, Davide, Elisa Castiglioni, Francesco Niro, Sara Mallia, Giulio Pompilio, and Aoife Gowran. "“Betwixt Mine Eye and Heart a League Is Took”: The Progress of Induced Pluripotent Stem-Cell-Based Models of Dystrophin-Associated Cardiomyopathy." International Journal of Molecular Sciences 21, no. 19 (September 23, 2020): 6997. http://dx.doi.org/10.3390/ijms21196997.
Full textAbstract:
The ultimate goal of precision disease modeling is to artificially recreate the disease of affected people in a highly controllable and adaptable external environment. This field has rapidly advanced which is evident from the application of patient-specific pluripotent stem-cell-derived precision therapies in numerous clinical trials aimed at a diverse set of diseases such as macular degeneration, heart disease, spinal cord injury, graft-versus-host disease, and muscular dystrophy. Despite the existence of semi-adequate treatments for tempering skeletal muscle degeneration in dystrophic patients, nonischemic cardiomyopathy remains one of the primary causes of death. Therefore, cardiovascular cells derived from muscular dystrophy patients’ induced pluripotent stem cells are well suited to mimic dystrophin-associated cardiomyopathy and hold great promise for the development of future fully effective therapies. The purpose of this article is to convey the realities of employing precision disease models of dystrophin-associated cardiomyopathy. This is achieved by discussing, as suggested in the title echoing William Shakespeare’s words, the settlements (or “leagues”) made by researchers to manage the constraints (“betwixt mine eye and heart”) distancing them from achieving a perfect precision disease model.
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Szűcs, Zsuzsanna, Éva Pinti, Irén Haltrich, Orsolya Pálné Szén, Tibor Nagy, Endre Barta, Gábor Méhes, et al. "An Ultra-Rare Manifestation of an X-Linked Recessive Disorder: Duchenne Muscular Dystrophy in a Female Patient." International Journal of Molecular Sciences 23, no. 21 (October 28, 2022): 13076. http://dx.doi.org/10.3390/ijms232113076.
Full textAbstract:
Duchenne muscular dystrophy (DMD) is the most common inherited muscle dystrophy. Patients are characterized by muscle weakness, gross motor delay, and elevated serum creatinine kinase (CK) levels. The disease is caused by mutations in the DMD gene located on the X chromosome. Due to the X-linked recessive inheritance pattern, DMD most commonly affects males, who are generally diagnosed between the age of 3–5 years. Here we present an ultra-rare manifestation of DMD in a female patient. Cytogenetic examination showed that she has a t(X;10)(p21.1;p12.1) translocation, which turned out to affect the DMD gene with one of the breakpoints located in exon 54 (detected by genome sequencing). The X-inactivation test revealed skewed X-inactivation (ratio 99:1). Muscle histology and dystrophin immunohistochemistry showed severe dystrophic changes and highly reduced dystrophin expression, respectively. These results, in accordance with the clinical picture and a highly elevated serum CK, led to the diagnosis of DMD. In conclusion, although in very rare cases, DMD can manifest in female patients as well. In this case, a balanced X-autosome reciprocal translocation disrupts the DMD gene and skewed X-inactivation leads to the manifestation of the DMD phenotype.
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Nogami, Ken'ichiro, Yusuke Maruyama, Fusako Sakai-Takemura, Norio Motohashi, Ahmed Elhussieny, Michihiro Imamura, Satoshi Miyashita, et al. "Pharmacological activation of SERCA ameliorates dystrophic phenotypes in dystrophin-deficient mdx mice." Human Molecular Genetics 30, no. 11 (April 5, 2021): 1006–19. http://dx.doi.org/10.1093/hmg/ddab100.
Full textAbstract:
Abstract Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder characterized by progressive muscular weakness because of the loss of dystrophin. Extracellular Ca2+ flows into the cytoplasm through membrane tears in dystrophin-deficient myofibers, which leads to muscle contracture and necrosis. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) takes up cytosolic Ca2+ into the sarcoplasmic reticulum, but its activity is decreased in dystrophic muscle. Here, we show that an allosteric SERCA activator, CDN1163, ameliorates dystrophic phenotypes in dystrophin-deficient mdx mice. The administration of CDN1163 prevented exercise-induced muscular damage and restored mitochondrial function. In addition, treatment with CDN1163 for 7 weeks enhanced muscular strength and reduced muscular degeneration and fibrosis in mdx mice. Our findings provide preclinical proof-of-concept evidence that pharmacological activation of SERCA could be a promising therapeutic strategy for DMD. Moreover, CDN1163 improved muscular strength surprisingly in wild-type mice, which may pave the new way for the treatment of muscular dysfunction.
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Sazani, Peter, Kirk P. Van Ness, Doreen L. Weller, Duane Poage, Keith Nelson, and and Stephen B. Shrewsbury. "Chemical and Mechanistic Toxicology Evaluation of Exon Skipping Phosphorodiamidate Morpholino Oligomers in mdx Mice." International Journal of Toxicology 30, no. 3 (May 2011): 322–33. http://dx.doi.org/10.1177/1091581811403504.
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AVI-4658 is a phosphorodiamidate morpholino oligomer (PMO) designed to induce skipping of dystrophin exon 51 and restore its expression in patients with Duchenne muscular dystrophy (DMD). Preclinically, restoration of dystrophin in the dystrophic mdx mouse model requires skipping of exon 23, achieved with the mouse-specific PMO, AVI-4225. Herein, we report the potential toxicological consequences of exon skipping and dystrophin restoration in mdx mice using AVI-4225. We also evaluated the toxicological effects of AVI-4658 in both mdx and wild-type mice. In both studies, animals were dosed once weekly for 12 weeks up to the maximum feasible dose of 960 mg/kg per injection. Both AVI-4658 and AVI-4225 were well-tolerated at all doses. Findings in AVI-4225-treated animals were generally limited to mild renal tubular basophilia/vacuolation, without any significant changes in renal function and with evidence of reversing. No toxicity associated with the mechanism of action of AVI-4225 in a dystrophic animal was observed.