title: Sarcolemmal reorganization in facioscapulohumeral muscular dystrophy.
abstract: OBJECTIVE
  We examined the sarcolemma of skeletal muscle from patients with facioscapulohumeral muscular dystrophy (FSHD1A) to learn if, as in other murine and human muscular dystrophies, its organization and relationship to nearby contractile structures are altered.
  
  
  METHODS
  Unfixed biopsies of control and FSHD deltoid and biceps muscles, snap-frozen at resting length, were cryosectioned, indirectly immunolabeled with fluorescent antibodies to sarcolemmal and myofibrillar markers, and examined with confocal microscopy to localize the immunolabeled proteins. Glutaraldehyde-fixed samples were stained with heavy metals, embedded, thin-sectioned, and examined with electron microscopy to determine the relationship between the sarcolemma and the underlying myofibrils.
  
  
  RESULTS
  Confocal microscopy showed that some of the structures at the sarcolemma in FSHD samples were misaligned with respect to the underlying contractile apparatus. Electron microscopy showed a significant increase in the distance between the sarcolemma and the nearest myofibrils, from less than 100 nm in controls to values as high as 550 nm in FSHD.
  
  
  CONCLUSIONS
  Our results show that the pathophysiology of FSHD includes novel changes in the organization of the sarcolemma and its association with nearby contractile structures and suggest that, as in other muscular dystrophies, the integrity of the sarcolemma may be compromised in FSHD.
authors.affiliation: Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Reed
authors.forename: Neil C
authors.initials: NC
authors.lastname: Porter
authors.forename: John
authors.initials: J
authors.lastname: Strong
authors.forename: David W
authors.initials: DW
authors.lastname: Pumplin
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Corse
authors.forename: Paul W
authors.initials: PW
authors.lastname: Luther
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Flanigan
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Bloch
mesh_terms: D003599:Cytoskeleton / Q000502:physiology; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D020391:Muscular Dystrophy, Facioscapulohumeral / Q000473:pathology* / Q000503:physiopathology*; D012508:Sarcolemma / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D013049:Spectrin / Q000378:metabolism
chemical_list: D009124:Muscle Proteins; D013049:Spectrin