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Extracellular matrix (ECM) pathologic remodeling underlies many disorders, including muscular dystrophy. Tissue decellularization removes cellular components while leaving behind ECM components. We generated on-slide decellularized tissue slices from genetically distinct dystrophic mouse models. The ECM of dystrophin- and sarcoglycan-deficient muscles had marked thrombospondin 4 deposition, while dysferlin-deficient muscle had excess decorin. Annexins A2 and A6 were present on all dystrophic decellularized ECMs, but annexin matrix deposition was excessive in dysferlin-deficient muscular dystrophy. Muscle-directed viral expression of annexin A6 resulted in annexin A6 in the ECM. C2C12 myoblasts seeded onto decellularized matrices displayed differential myoblast mobility and fusion. Dystrophin-deficient decellularized matrices inhibited myoblast mobility, while dysferlin-deficient decellularized matrices enhanced myoblast movement and differentiation. Myoblasts treated with recombinant annexin A6 increased mobility and fusion like that seen on dysferlin-deficient decellularized matrix and demonstrated upregulation of ECM and muscle cell differentiation genes. These findings demonstrate specific fibrotic signatures elicit effects on myoblast activity.

This study determined the frequency and impact of symptoms on quality of life in patients diagnosed with limb girdle muscular dystrophy (LGMD). Participants with a diagnosis of LGMD in registries based at the Coalition to Cure Calpain-3, the Jain foundation, and the Global FKRP Registry competed a survey to report the frequency and relative impact of themes and symptoms of LGMD. Frequency, mean impact, and population impact scores were calculated, and responses were categorized by age, symptom duration, gender, employment status, use of assistive devices, and LGMD subtypes. 134 participants completed the survey. The most prevalent themes included an inability to do activities (100%), limitation with mobility (99.3%), and lower extremity weakness (97.0%). Themes with the greatest impact were: limitations with mobility, lower extremity weakness, and an inability to do activities. Symptom duration and the use of assistive devices were associated with the presence of multiple themes. Employment was associated with the impact of several themes with no differences in frequency. The prevalence and impact of these themes vary in the LMGD population. The most prevalent and impactful themes were related to weakness, but additional concerns related to emotional challenges should also be considered in clinical and research settings.

Introduction/aimsThere is debate about whether and to what extent either respiratory or cardiac dysfunction occurs in patients with dysferlinopathy. This study aimed to establish definitively whether dysfunction in either system is part of the dysferlinopathy phenotype.MethodsAs part of the Jain Foundation's International Clinical Outcome Study (COS) for dysferlinopathy, objective measures of respiratory and cardiac function were collected twice, with a 3-y interval between tests, in 188 genetically confirmed patients aged 11-86 y (53% female). Measures included forced vital capacity (FVC), electrocardiogram (ECG), and echocardiogram (echo).ResultsMean FVC was 90% predicted at baseline, decreasing to 88% at year 3. FVC was less than 80% predicted in 44 patients (24%) at baseline and 48 patients (30%) by year 3, including ambulant participants. ECGs showed P-wave abnormalities indicative of delayed trans-atrial conduction in 58% of patients at baseline, representing a risk for developing atrial flutter or fibrillation. The prevalence of impaired left ventricular function or hypertrophy was comparable to that in the general population.DiscussionThese results demonstrate clinically significant respiratory impairment and abnormal atrial conduction in some patients with dysferlinopathy. Therefore, we recommend that annual or biannual follow-up should include FVC measurement, enquiry about arrhythmia symptoms and peripheral pulse palpation to assess cardiac rhythm. However, periodic specialist cardiac review is probably not warranted unless prompted by symptoms or abnormal pulse findings.

[Introduction/Aims] There is debate about whether and to what extent either respiratory or cardiac dysfunction occurs in patients with dysferlinopathy. This study aimed to establish definitively whether dysfunction in either system is part of the dysferlinopathy phenotype., [Methods] As part of the Jain Foundation's International Clinical Outcome Study (COS) for dysferlinopathy, objective measures of respiratory and cardiac function were collected twice, with a 3-y interval between tests, in 188 genetically confirmed patients aged 11–86 y (53% female). Measures included forced vital capacity (FVC), electrocardiogram (ECG), and echocardiogram (echo)., [Results] Mean FVC was 90% predicted at baseline, decreasing to 88% at year 3. FVC was less than 80% predicted in 44 patients (24%) at baseline and 48 patients (30%) by year 3, including ambulant participants. ECGs showed P-wave abnormalities indicative of delayed trans-atrial conduction in 58% of patients at baseline, representing a risk for developing atrial flutter or fibrillation. The prevalence of impaired left ventricular function or hypertrophy was comparable to that in the general population., [Discussion] These results demonstrate clinically significant respiratory impairment and abnormal atrial conduction in some patients with dysferlinopathy. Therefore, we recommend that annual or biannual follow-up should include FVC measurement, enquiry about arrhythmia symptoms and peripheral pulse palpation to assess cardiac rhythm. However, periodic specialist cardiac review is probably not warranted unless prompted by symptoms or abnormal pulse findings.

Muscle repair in dysferlinopathies is defective. Although macrophage (Mø)-rich infiltrates are prominent in damaged skeletal muscles of patients with dysferlinopathy, the contribution of the immune system to the disease pathology remains to be fully explored. Numbers of both pro-inflammatory M1 Mø and effector T cells are increased in muscle of dysferlin-deficient BlAJ mice. In addition, symptomatic BlAJ mice have increased muscle production of immunoproteasome. In vitro analyses using bone marrow-derived Mø of BlAJ mice show that immunoproteasome inhibition results in C3aR1 and C5aR1 downregulation and upregulation of M2-associated signaling. Administration of immunoproteasome inhibitor ONX-0914 to BlAJ mice rescues muscle function by reducing muscle infiltrates and fibro-adipogenesis. These findings reveal an important role of immunoproteasome in the progression of muscular dystrophy in BlAJ mouse and suggest that inhibition of immunoproteasome may produce therapeutic benefit in dysferlinopathy.

INTRODUCTION: We conducted an open-label study to examine the effects of the flavonoid (-)-epicatechin in seven ambulatory adult patients with Becker muscular dystrophy (BMD). METHODS: Seven participants received (-)-epicatechin 50 mg twice per day for 8 weeks. Pre- and postprocedures included biceps brachii biopsy to assess muscle structure and growth-relevant endpoints by western blotting, mitochondria volume measurement, and cristae abundance by electron microscopy, graded exercise testing, and muscle strength and function tests. RESULTS: Western blotting showed significantly increased levels of enzymes modulating cellular bioenergetics (liver kinase B1 and 5-adenosine monophosphate-activated protein kinase). Peroxisome proliferator-activated receptor gamma coactivator-1alpha, a transcriptional coactivator of genes involved in mitochondrial biogenesis and cristae-associated mitofilin levels, increased as did cristae abundance. Muscle and plasma follistatin increased significantly while myostatin decreased. Markers of skeletal muscle regeneration myogenin, myogenic regulatory factor-5, myoblast determination protein 1, myocyte enhancer factor-2, and structure-associated proteins, including dysferlin, utrophin, and intracellular creatine kinase, also increased. Exercise testing demonstrated decreased heart rate, maximal oxygen consumption per kilogram, and plasma lactate levels at defined workloads. Tissue saturation index improved in resting and postexercise states. DISCUSSION: (-)-Epicatechin, an exercise mimetic, appears to have short-term positive effects on tissue biomarkers indicative of mitochondrial biogenesis and muscle regeneration, and produced improvements in graded exercise testing parameters in patients with BMD.

IntroductionDysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice.MethodsMuscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice.ResultsMuscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles.DiscussionWe conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies.

IntroductionDysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice.MethodsMuscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice.ResultsMuscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles.DiscussionWe conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies.

QC 20220301

Skeletal muscle undergoes many micro-membrane lesions at physiological state. Based on their sizes and magnitude these lesions are repaired via different complexes on a specific spatio-temporal manner. One of the major repair complex is a dysferlin-dependent mechanism. Accordingly, mutations in the DYSF gene encoding dysferlin results in the development of several muscle pathologies called dysferlinopathies, where abnormalities of the membrane repair process have been characterized in patients and animal models. Recent efforts have been deployed to decipher the function of dysferlin, they shed light on its direct implication in sarcolemma resealing after injuries. These discoveries served as a strong ground to design therapeutic approaches for dysferlin-deficient patients. This review detailed the different partners and function of dysferlin and positions the sarcolemma repair in normal and pathological conditions.

De neutrofila granulocyterna ingår i det icke specifika immunförsvaret och fagocyterarmikroorganismer och rester från kroppens egna celler. Neutrofilen innehåller fyra olika typerav granula, som vid aktivering av cellen kan uppregleras till plasmamembranet. Proteinetdysferlin har bevisats förekomma i membranet i en del av dessa granuler. Det tros ha en roll imembran fusion och underhåll av membranet.Dysferlin är ett transmembrant protein av typ II, och proteinet saknas i funktionellt tillståndvid sjukdomstillstånden Limb-Girdle muskeldystrofi 2B och Miyoshi myopati. I arbetetkommer en metod att utvecklas som skall användas till att studera proteinet dysferlin hos deneutrofila granulocyterna vid olika funktionella tillstånd. Mängden dysferlin iplasmamembranet hos oaktiverade och aktiverade celler jämförs också i arbetet.Antikroppar har använts för att märka in dysferlinet. En primär antikropp som binder tillproteinet och en sekundär antikropp som binder till den primära. Den sekundära antikroppenhar en fluorescent färg konjugerad. För analyserna har en FACS som ger diagram överfluorescenssignalen använts och ett konfokalmikroskop som avbildar cellen i olika skikt, vilkakan användas för att ta fram en tredimensionell bild av cellen.Både intracellulär och extracellulär inmärkning av dysferlin har gjorts och olika parametrarhar varierats mellan försöken. FACS analyserna har visat på att dysferlin möjligtvis skullekunna finnas i små mängder i plasmamembranet hos oaktiverade celler. Mängden dysferlin iplasmamembranet ökar vid aktivering av cellen, till följd av uppreglering av granula. Studier ikonfokalmikroskopet har visat på att dysferlin finns i cellmembranet hos aktiverade celler ochatt det finns lokaliserat till cytoplasman hos oaktiverade celler.

De neutrofila granulocyterna ingår i det icke specifika immunförsvaret och fagocyterarmikroorganismer och rester från kroppens egna celler. Neutrofilen innehåller fyra olika typerav granula, som vid aktivering av cellen kan uppregleras till plasmamembranet. Proteinetdysferlin har bevisats förekomma i membranet i en del av dessa granuler. Det tros ha en roll imembran fusion och underhåll av membranet.Dysferlin är ett transmembrant protein av typ II, och proteinet saknas i funktionellt tillståndvid sjukdomstillstånden Limb-Girdle muskeldystrofi 2B och Miyoshi myopati. I arbetetkommer en metod att utvecklas som skall användas till att studera proteinet dysferlin hos deneutrofila granulocyterna vid olika funktionella tillstånd. Mängden dysferlin iplasmamembranet hos oaktiverade och aktiverade celler jämförs också i arbetet.Antikroppar har använts för att märka in dysferlinet. En primär antikropp som binder tillproteinet och en sekundär antikropp som binder till den primära. Den sekundära antikroppenhar en fluorescent färg konjugerad. För analyserna har en FACS som ger diagram överfluorescenssignalen använts och ett konfokalmikroskop som avbildar cellen i olika skikt, vilkakan användas för att ta fram en tredimensionell bild av cellen.Både intracellulär och extracellulär inmärkning av dysferlin har gjorts och olika parametrarhar varierats mellan försöken. FACS analyserna har visat på att dysferlin möjligtvis skullekunna finnas i små mängder i plasmamembranet hos oaktiverade celler. Mängden dysferlin iplasmamembranet ökar vid aktivering av cellen, till följd av uppreglering av granula. Studier ikonfokalmikroskopet har visat på att dysferlin finns i cellmembranet hos aktiverade celler ochatt det finns lokaliserat till cytoplasman hos oaktiverade celler.

© 2017 Umakhanova, Bardakov, Mavlikeev, Chernova, Magomedova, Akhmedova, Yakovlev, Dalgatov, Fedotov, Isaev and Deev.To date, over 30 genes with mutations causing limb-girdle muscle dystrophy have been described. Dysferlinopathies are a form of limb-girdle muscle dystrophy type 2B with an incidence ranging from 1:1,300 to 1:200,000 in different populations. In 1996, Dr. S. N. Illarioshkin described a family from the Botlikhsky district of Dagestan, where limb-girdle muscle dystrophy type 2B and Miyoshi myopathy were diagnosed in 12 members from three generations of a large Avar family. In 2000, a previously undescribed mutation in the DYSF gene (c.TG573/574AT; p. Val67Asp) was detected in the affected members of this family. Twenty years later, in this work, we re-examine five known and seven newly affected family members previously diagnosed with dysferlinopathy. We observed disease progression in family members who were previously diagnosed and noted obvious clinical polymorphism of the disease. A typical clinical case is provided.

The "Funding" section should be: This work was funded by Human Stem Cells Institute PJSC and Roman V. Deev. Theoretical part of this work was supported by Russian Scientific Foundation grant (14-15-00916). Ivan A. Yakovlev and Mikhail O. Mavlikeev were supported by the Russian Government Program of Competitive Growth of Kazan Federal University. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way.

Dysferlinopathies belong to neuromuscular diseases associated with aberrant expression and/or function of dysferlin protein in skeletal muscle, which is caused by mutations in the dysf (dystrophy-associated fer-1-like, DYSF) gene. Because of the large size of the codon-optimized dysf coding region (6243 bp), adenoviral vectors are suitable for the creation of genetic constructs, which are capable of delivering a large amount of recombinant genetic information into both dividing and non-dividing cells, as well as provide a high level of transgene expression. We generated a recombinant adenovirus serotype 5 encoding a codon-optimized gene for human dysferlin (Ad5-Dysf) and analysed recombinant protein expression in vitro in HEK-293T cell line.

Dysferlinopathies is a group of autosomal-recessive inherited neuromuscular diseases, which are characterized by defect in mRNA expression or in functionioning of dysferlin protein, appearing in about 1/200 000 births. Dysferlin is encoded by DYSF gene (Dystrophy-associated fer-1- like). It's disruption can cause various types of primary dysferlinopathies, which include Miyoshi myopathy (MM), Limb-girdle Muscular Dystrophy type 2B (LGMD2B) and distal myopathy with anterior tibial onset. Also, dysferlin deficiency can be associated with other diseases, such as caveolin- And calpainopathies. Here we discuss dysferlin protein structure and function, it's clinical phenotypes, known animal models and developing treatment strategies for dysferlinopathies. © Human stem cells institute, 2013.

The "Funding" section should be: This work was funded by Human Stem Cells Institute PJSC and Roman V. Deev. Theoretical part of this work was supported by Russian Scientific Foundation grant (14-15-00916). Ivan A. Yakovlev and Mikhail O. Mavlikeev were supported by the Russian Government Program of Competitive Growth of Kazan Federal University. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way.

© 2017 Umakhanova, Bardakov, Mavlikeev, Chernova, Magomedova, Akhmedova, Yakovlev, Dalgatov, Fedotov, Isaev and Deev.To date, over 30 genes with mutations causing limb-girdle muscle dystrophy have been described. Dysferlinopathies are a form of limb-girdle muscle dystrophy type 2B with an incidence ranging from 1:1,300 to 1:200,000 in different populations. In 1996, Dr. S. N. Illarioshkin described a family from the Botlikhsky district of Dagestan, where limb-girdle muscle dystrophy type 2B and Miyoshi myopathy were diagnosed in 12 members from three generations of a large Avar family. In 2000, a previously undescribed mutation in the DYSF gene (c.TG573/574AT; p. Val67Asp) was detected in the affected members of this family. Twenty years later, in this work, we re-examine five known and seven newly affected family members previously diagnosed with dysferlinopathy. We observed disease progression in family members who were previously diagnosed and noted obvious clinical polymorphism of the disease. A typical clinical case is provided.

Dysferlinopathies is a group of autosomal-recessive inherited neuromuscular diseases, which are characterized by defect in mRNA expression or in functionioning of dysferlin protein, appearing in about 1/200 000 births. Dysferlin is encoded by DYSF gene (Dystrophy-associated fer-1- like). It's disruption can cause various types of primary dysferlinopathies, which include Miyoshi myopathy (MM), Limb-girdle Muscular Dystrophy type 2B (LGMD2B) and distal myopathy with anterior tibial onset. Also, dysferlin deficiency can be associated with other diseases, such as caveolin- And calpainopathies. Here we discuss dysferlin protein structure and function, it's clinical phenotypes, known animal models and developing treatment strategies for dysferlinopathies. © Human stem cells institute, 2013.

Dysferlinopathies belong to neuromuscular diseases associated with aberrant expression and/or function of dysferlin protein in skeletal muscle, which is caused by mutations in the dysf (dystrophy-associated fer-1-like, DYSF) gene. Because of the large size of the codon-optimized dysf coding region (6243 bp), adenoviral vectors are suitable for the creation of genetic constructs, which are capable of delivering a large amount of recombinant genetic information into both dividing and non-dividing cells, as well as provide a high level of transgene expression. We generated a recombinant adenovirus serotype 5 encoding a codon-optimized gene for human dysferlin (Ad5-Dysf) and analysed recombinant protein expression in vitro in HEK-293T cell line.