Loss of supervillin causes myopathy with myofibrillar disorganization and autophagic vacuoles
UMass Chan AffiliationsLuna Lab
Division of Cell Biology and Imaging, Department of Radiology
Amino Acids, Peptides, and Proteins
Cellular and Molecular Physiology
Molecular and Cellular Neuroscience
Musculoskeletal, Neural, and Ocular Physiology
Nervous System Diseases
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AbstractThe muscle specific isoform of the supervillin protein (SV2), encoded by the SVIL gene, is a large sarcolemmal myosin II- and F-actin-binding protein. Supervillin (SV2) binds and co-localizes with costameric dystrophin and binds nebulin, potentially attaching the sarcolemma to myofibrillar Z-lines. Despite its important role in muscle cell physiology suggested by various in vitro studies, there are so far no reports of any human disease caused by SVIL mutations. We here report four patients from two unrelated, consanguineous families with a childhood/adolescence onset of a myopathy associated with homozygous loss-of-function mutations in SVIL. Wide neck, anteverted shoulders and prominent trapezius muscles together with variable contractures were characteristic features. All patients showed increased levels of serum creatine kinase but no or minor muscle weakness. Mild cardiac manifestations were observed. Muscle biopsies showed complete loss of large supervillin isoforms in muscle fibres by western blot and immunohistochemical analyses. Light and electron microscopic investigations revealed a structural myopathy with numerous lobulated muscle fibres and considerable myofibrillar alterations with a coarse and irregular intermyofibrillar network. Autophagic vacuoles, as well as frequent and extensive deposits of lipoproteins, including immature lipofuscin, were observed. Several sarcolemma-associated proteins, including dystrophin and sarcoglycans, were partially mis-localized. The results demonstrate the importance of the supervillin (SV2) protein for the structural integrity of muscle fibres in humans and show that recessive loss-of-function mutations in SVIL cause a distinctive and novel myopathy.
Hedberg-Oldfors C, Meyer R, Nolte K, Abdul Rahim Y, Lindberg C, Karason K, Thuestad IJ, Visuttijai K, Geijer M, Begemann M, Kraft F, Lausberg E, Hitpass L, Götzl R, Luna EJ, Lochmüller H, Koschmieder S, Gramlich M, Gess B, Elbracht M, Weis J, Kurth I, Oldfors A, Knopp C. Loss of supervillin causes myopathy with myofibrillar disorganization and autophagic vacuoles. Brain. 2020 Aug 1;143(8):2406-2420. doi: 10.1093/brain/awaa206. PMID: 32779703; PMCID: PMC7447519. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/41534
Full author list omitted for brevity. For the full list of authors, see article.