Muscle membrane-skeleton protein changes and histopathological characterization of muscle-eye-brain disease.
Muscle-eye-brain disease belongs to congenital muscular dystrophies with central nervous system abnormalities. The etiology of MEB is still unknown, but abnormal immunoreactivity for laminin-2 has been reported. To evaluate disease progression in muscle tissue, 32 biopsy specimens from 17 muscle-eye-brain patients were analysed. The samples of four patients were studied by immunohistochemical techniques and by quantitative Western blotting. The samples showed a great variation in the muscle pathology. Regenerative fibers and mild fiber size variation were present in over 60%. At infancy, necrotic and regenerative fibers were common, while fat infiltration was the most prominent finding in the age group over five years. In quantitative studies, the amount of laminin alpha 2 chain was clearly reduced to 10-20% of normal. In contrast, laminin beta 2 chain was overexpressed in the Western blotting studies. These findings may reflect a yet unidentified primary disturbance in the basement membrane composition and function.
Auranen
M
M
Department of Anatomy, University of Helsinki, Finland. mauranen@cc.helsinki.fi
Rapola
J
J
Pihko
H
H
Haltia
M
M
Leivo
I
I
Soinila
S
S
Virtanen
I
I
Kalimo
H
H
Anderson
L V
LV
Santavuori
P
P
Somer
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D015153:Blotting, Western; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D049030:Dystroglycans; D016189:Dystrophin / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007797:Laminin / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism* / Q000473:pathology*; D009136:Muscular Dystrophies / Q000151:congenital / Q000378:metabolism* / Q000473:pathology*
D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D016189:Dystrophin; D007797:Laminin; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D049030:Dystroglycans