CRISPR/Cas correction of muscular dystrophies

Muscular dystrophies constitute a group of genetic disorders that cause weakness and progressive loss of skeletal muscle mass. Among them, Miyoshi muscular dystrophy 1 (MMD1), limb girdle muscular dystrophy type R2 (LGMDR2/2B), and LGMDR12 (2L) are characterized by mutation in gene encoding key membrane-repair protein, which leads to severe dysfunctions in sarcolemma repair. Cell membrane disruption is a physiological event induced by mechanical stress, such as muscle contraction and stretching. Like many eukaryotic cells, muscle fibers possess a protein machinery ensuring fast resealing of damaged plasma membrane. Members of the annexins A (ANXA) family belong to this protein machinery. ANXA are small soluble proteins, twelve in number in humans, which share the property of binding to membranes exposing negatively-charged phospholipids in the presence of calcium (Ca2+). Many ANXA have been reported to participate in membrane repair of varied cell types and species, including human skeletal muscle cells in which they may play a collective role in protection and repair of the sarcolemma. Here, we discuss the participation of ANXA in membrane repair of healthy skeletal muscle cells and how dysregulation of ANXA expression may impact the clinical severity of muscular dystrophies.

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Role of CMR Imaging in Diagnostics and Evaluation of Cardiac Involvement in Muscle Dystrophies

Current Heart Failure Reports ◽

10.1007/s11897-021-00521-2 ◽

2021 ◽

Author(s):

Edyta Blaszczyk ◽

Jan Gröschel ◽

Jeanette Schulz-Menger

Keyword(s):

Clinical Care ◽

Fatty Infiltration ◽

Severe Heart Failure ◽

Diffuse Fibrosis ◽

Muscular Dystrophies ◽

Invasive Technique ◽

Myocardial Tissue ◽

Therapeutic Decisions ◽

Cardiovascular Evaluation ◽

Unique Capability

Abstract Purpose of Review This review aims to outline the utility of cardiac magnetic resonance (CMR) in patients with different types of muscular dystrophies for the assessment of myocardial involvement, risk stratification and in guiding therapeutic decisions. Recent Findings In patients suffering from muscular dystrophies (MD), even mild initial dysfunction may lead to severe heart failure over a time course of years. CMR plays an increasing role in the diagnosis and clinical care of these patients, mostly due to its unique capability to precisely characterize subclinical and progressive changes in cardiac geometry, function in order to differentiate myocardial injury it allows the identification of inflammation, focal and diffuse fibrosis as well as fatty infiltration. CMR may provide additional information in addition to the physical examination, laboratory tests, ECG, and echocardiography. Summary Further trials are needed to investigate the potential impact of CMR on the therapeutic decision-making as well as the assessment of long-term prognosis in different forms of muscular dystrophies. In addition to the basic cardiovascular evaluation, CMR can provide a robust, non-invasive technique for the evaluation of subclinical myocardial tissue injury like fat infiltration and focal and diffuse fibrosis. Furthermore, CMR has a unique capability to detect the progression of myocardial tissue damage in patients with a preserved systolic function.

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THE MUSCULAR DYSTROPHIES.

The Lancet ◽

10.1016/s0140-6736(01)50056-2 ◽

1925 ◽

Vol 206 (5336) ◽

pp. 1179-1180

Keyword(s):

Muscular Dystrophies

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Bioengineered in vitro skeletal muscles as new tools for muscular dystrophies preclinical studies

Journal of Tissue Engineering ◽

10.1177/2041731420981339 ◽

2021 ◽

Vol 12 ◽

pp. 204173142098133

Author(s):

Juan M. Fernández-Costa ◽

Xiomara Fernández-Garibay ◽

Ferran Velasco-Mallorquí ◽

Javier Ramón-Azcón

Keyword(s):

Skeletal Muscle ◽

Tissue Engineering ◽

Electrical Stimulation ◽

Skeletal Muscles ◽

Screening Tools ◽

Muscular Dystrophies ◽

Preclinical Studies ◽

Technological Advances ◽

Topographical Cues

Muscular dystrophies are a group of highly disabling disorders that share degenerative muscle weakness and wasting as common symptoms. To date, there is not an effective cure for these diseases. In the last years, bioengineered tissues have emerged as powerful tools for preclinical studies. In this review, we summarize the recent technological advances in skeletal muscle tissue engineering. We identify several ground-breaking techniques to fabricate in vitro bioartificial muscles. Accumulating evidence shows that scaffold-based tissue engineering provides topographical cues that enhance the viability and maturation of skeletal muscle. Functional bioartificial muscles have been developed using human myoblasts. These tissues accurately responded to electrical and biological stimulation. Moreover, advanced drug screening tools can be fabricated integrating these tissues in electrical stimulation platforms. However, more work introducing patient-derived cells and integrating these tissues in microdevices is needed to promote the clinical translation of bioengineered skeletal muscle as preclinical tools for muscular dystrophies.

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Thigh and Leg Muscle MRI Findings in GNE Myopathy

Journal of Neuromuscular Diseases ◽

10.3233/jnd-210629 ◽

2021 ◽

pp. 1-8

Author(s):

Farzad Fatehi ◽

Soroor Advani ◽

Ali Asghar Okhovat ◽

Bentolhoda Ziaadini ◽

Hosein Shamshiri ◽

...

Keyword(s):

Tibialis Anterior ◽

Vastus Lateralis ◽

Fatty Infiltration ◽

Muscular Dystrophies ◽

Tibialis Posterior ◽

Muscle Mri ◽

Muscle Involvement ◽

Fat Infiltration ◽

Gne Myopathy ◽

Adductor Magnus

Background: Muscle MRI protocols have been developed to assess muscle involvement in a wide variety of muscular dystrophies. Different muscular dystrophies can involve muscle groups in characteristic patterns. These patterns can be identified in muscle MRI in the form of fatty infiltration. Objective: This study was conducted to add the existing knowledge of muscle MRI in GNE myopathy and evaluate the correlation of muscular involvement with different gene mutations. Methods: The MRI scans of the 18 GNE patients were analyzed retrospectively. Cluster analysis was done for grouping the muscles and patients. Results: The four muscles with the highest fat infiltration were adductor magnus, tibialis anterior, semitendinosus, and semimembranosus. Furthermore, three clusters of muscle involvement were found, including cluster 1, typical muscle involvement indicating muscles with the highest infiltration: extensor digitorum longus, gracilis, biceps femoris, soleus, gastrocnemius medial, adductor longus, tibialis anterior, adductor magnus, semimembranosus, semitendinosus; cluster 2, less typical muscle involvement indicating muscles with intermediate fat infiltration, peroneus longus, gastrocnemius lateral, and minimal fat infiltration in most of the patients, i.e., tibialis posterior; and cluster 3, atypical muscle involvement with low-fat infiltration: rectus femoris, sartorius, vastus intermedius, vastus medialis, and vastus lateralis. Conclusions: This study found three clusters of muscle involvement and three groups of patients among GNE patients. Hamstring muscles and the anterior compartment of the lower leg were the muscles with the highest fat infiltration. Moreover, a weak genotype-muscle MRI association was found in which tibialis posterior was more involved in patients with the most frequent mutation, i.e., C.2228T > C (p.M743T) mutation; however, this finding may be related to longer disease duration.

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