A Naturally Occurring Human Minidysferlin Protein Repairs Sarcolemmal Lesions in a Mouse Model of Dysferlinopathy

Krahn, Martin; Wein, Nicolas; Bartoli, Marc; Lostal, William; Courrier, Sébastien; Bourg-Alibert, N.; Nguyen, Karine; Vial, Christophe; Streichenberger, Nathalie; Labelle, Véronique; Depétris, D.; Pécheux, Christophe; Cau, Pierre; Richard, Isabelle; Lévy, Nicolas

doi:10.1126/scitranslmed.3000951

Cited by 75 publications

(74 citation statements)

References 39 publications

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“…Currently, no causal pharmacological treatment is available for patients affected by the progressive and debilitating muscular dystrophies caused by dysferlin deficiency. Based on clinical observations of dysferlinopathy patients with internally truncated dysferlin molecules and mild phenotype (26,27), exon-skipping strategies have been developed (28,29), analogous to strategies currently tested in patients with dystrophinopathies (30,31). Other experimental treatment possibilities include the generation of small dysferlin molecules suitable for adeno-associated virus (AAV)-mediated gene delivery (27), or expression of dysferlin coding fragments which recombine after dual adeno-associated virus-mediated gene transfer to generate one transcript able to produce the full-length protein (32).…”

Section: Discussionmentioning

confidence: 99%

“…Based on clinical observations of dysferlinopathy patients with internally truncated dysferlin molecules and mild phenotype (26,27), exon-skipping strategies have been developed (28,29), analogous to strategies currently tested in patients with dystrophinopathies (30,31). Other experimental treatment possibilities include the generation of small dysferlin molecules suitable for adeno-associated virus (AAV)-mediated gene delivery (27), or expression of dysferlin coding fragments which recombine after dual adeno-associated virus-mediated gene transfer to generate one transcript able to produce the full-length protein (32). Stop codon read-through, using Ataluren (PTC124), has been suggested as a possible therapy for patients harboring non-sense mutations (33), and cell based therapies have also been recently proposed using mesangioblasts (34).…”

Section: Discussionmentioning

confidence: 99%

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Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Azakir

Fulvio

Kinter

et al. 2012

Journal of Biological Chemistry

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Background: Dysferlin encoded by mis-sense alleles is rapidly degraded in skeletal muscle. Results: Proteasomal inhibitors increase dysferlin levels, restore membrane repair and myotube formation in patient-derived myoblasts harboring mis-sense mutated dysferlin. Conclusion: Proteasomal inhibition restores function of mis-sense mutated dysferlin. Significance: Inhibiting the degradation of mis-sense mutated dysferlin may be a therapeutic strategy for dysferlinopathies with certain mis-sense mutations.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Azakir

Fulvio

Kinter

et al. 2012

Journal of Biological Chemistry

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“…Furthermore, biologically derived mini-dysferlin C72 bears similarity to a truncated dysferlin identified in a mildly affected dysferlinopathy patient with a genomic deletion within the DYSF gene (Krahn et al, 2010). Remarkably, this patient-derived minidysferlin also bears the last two C2 domains and transmembrane domain and was shown to functionally restore defective membrane repair when expressed in dysferlin-deficient mouse muscle fibers (Krahn et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

Calpains, Cleaved Mini-Dysferlin_C72, and L-Type Channels Underpin Calcium-Dependent Muscle Membrane Repair

et al. 2013

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Dysferlin is proposed as a key mediator of calcium-dependent muscle membrane repair, although its precise role has remained elusive. Dysferlin interacts with a new membrane repair protein, mitsugumin 53 (MG53), an E3 ubiquitin ligase that shows rapid recruitment to injury sites. Using a novel ballistics assay in primary human myotubes, we show it is not full-length dysferlin recruited to sites of membrane injury but an injury-specific calpain-cleavage product, mini-dysferlin C72 . Mini-dysferlin C72 -rich vesicles are rapidly recruited to injury sites and fuse with plasma membrane compartments decorated by MG53 in a process coordinated by L-type calcium channels. Collective interplay between activated calpains, dysferlin, and L-type channels explains how muscle cells sense a membrane injury and mount a specialized response in the unique local environment of a membrane injury. Mini-dysferlin C72 and MG53 form an intricate lattice that intensely labels exposed phospholipids of injury sites, then infiltrates and stabilizes the membrane lesion during repair. Our results extend functional parallels between ferlins and synaptotagmins. Whereas otoferlin exists as long and short splice isoforms, dysferlin is subject to enzymatic cleavage releasing a synaptotagmin-like fragment with a specialized protein-or phospholipid-binding role for muscle membrane repair.

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“…Thus, these model systems may not fully represent the role of dysferlin in mature myofibers. Studies performed in mature muscle have relied on electron microscopy of dysferlinopathic muscle and on laser wounding to study dysferlin and its function as a sarcolemmal repair protein (2,3,(36)(37)(38). However, the ability of laser wounding to predict the outcome of interventional treatments for dysferlinopathies has been recently questioned (39).…”

Section: Discussionmentioning

confidence: 99%

Dysferlin stabilizes stress-induced Ca ²⁺ signaling in the transverse tubule membrane

Kerr

Ziman

Mueller

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

114

176

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Dysferlinopathies, most commonly limb girdle muscular dystrophy 2B and Miyoshi myopathy, are degenerative myopathies caused by mutations in the DYSF gene encoding the protein dysferlin. Studies of dysferlin have focused on its role in the repair of the sarcolemma of skeletal muscle, but dysferlin's association with calcium (Ca 2+ ) signaling proteins in the transverse (t-) tubules suggests additional roles. Here, we reveal that dysferlin is enriched in the t-tubule membrane of mature skeletal muscle fibers. Following experimental membrane stress in vitro, dysferlin-deficient muscle fibers undergo extensive functional and structural disruption of the t-tubules that is ameliorated by reducing external [Ca 2+ ] or blocking L-type Ca 2+ channels with diltiazem. Furthermore, we demonstrate that diltiazem treatment of dysferlin-deficient mice significantly reduces eccentric contraction-induced t-tubule damage, inflammation, and necrosis, which resulted in a concomitant increase in postinjury functional recovery. Our discovery of dysferlin as a t-tubule protein that stabilizes stress-induced Ca 2+ signaling offers a therapeutic avenue for limb girdle muscular dystrophy 2B and Miyoshi myopathy patients.excitation-contraction coupling | dihydropyridine receptor | triad junction | muscle injury D ysferlinopathies are degenerative myopathies secondary to mutations in the gene encoding the protein dysferlin. These myopathies, most commonly limb girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy (MM), are independent of motor neuron activation (1), indicating that they are myogenic in origin. Dysferlin is a 230-kDa protein composed of seven C2 domains with homology to synaptotagmin (2, 3) and a single transmembrane domain near its C terminus (4, 5). The complexity of dysferlin's potential role in muscle is highlighted by the number of its purported functions, including membrane repair (2, 3), vesicle fusion (4), microtubule regulation (5, 6), cell adhesion (7,8), and intercellular signaling (9). Understanding the contributions of dysferlin to the maintenance of normal skeletal muscle function is critical for the development of appropriate therapies for patients diagnosed with LGMD2B and MM.Recently, we demonstrated the localization of dysferlin at the A-I junction in mature muscle fibers (10). These results agree with earlier reports associating dysferlin with the dihydropyridine receptor (DHPR, L-type Ca 2+ channel), Ahnak, caveolin 3, and several other proteins involved in Ca 2+ -based signaling and the function of transverse (t-) tubules (11)(12)(13)(14). Consistent with this localization and the potential for a functional role in this specialized compartment, dysferlin-deficient murine muscle demonstrates altered transverse tubule (t-tubule) structure (15) as well as increased oxidative stress (16, 17), inflammation, and necrosis (18-20) after injury.Here we demonstrate that dysferlin is enriched in the t-tubule membrane, where it contributes to the maintenance of the t-tubule and Ca 2+ homeostasis. We show...

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A Naturally Occurring Human Minidysferlin Protein Repairs Sarcolemmal Lesions in a Mouse Model of Dysferlinopathy

Abstract: A naturally occurring miniversion of the dysferlin protein found in a patient shows that gene therapy by minigene transfer may be possible in dysferlinopathies.

Cited by 75 publications

References 39 publications

Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Calpains, Cleaved Mini-Dysferlin_C72, and L-Type Channels Underpin Calcium-Dependent Muscle Membrane Repair

Dysferlin stabilizes stress-induced Ca ²⁺ signaling in the transverse tubule membrane

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A Naturally Occurring Human Minidysferlin Protein Repairs Sarcolemmal Lesions in a Mouse Model of Dysferlinopathy

Abstract: A naturally occurring miniversion of the dysferlin protein found in a patient shows that gene therapy by minigene transfer may be possible in dysferlinopathies.

Cited by 75 publications

References 39 publications

Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells

Calpains, Cleaved Mini-DysferlinC72, and L-Type Channels Underpin Calcium-Dependent Muscle Membrane Repair

Dysferlin stabilizes stress-induced Ca 2+ signaling in the transverse tubule membrane

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Resources

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Calpains, Cleaved Mini-Dysferlin_C72, and L-Type Channels Underpin Calcium-Dependent Muscle Membrane Repair

Dysferlin stabilizes stress-induced Ca ²⁺ signaling in the transverse tubule membrane