Ubiquitinated inclusions in inclusion-body myositis patients are immunoreactive for cathepsin D but not beta-amyloid.
The nature of the inclusions in the human muscle disease inclusion-body myositis (IBM) has been the subject of debate. Parallels with Alzheimer's disease have been drawn after these inclusions were found to be ubiquitinated, and immunoreactive with antibodies to beta-amyloid (A beta) and certain amyloid-associated proteins. We have used a battery of antibodies against A beta and associated proteins to immunostain muscle biopsies from patients with IBM. Although the inclusions are ubiquitinated, we could not show immunoreactivity for A beta or the associated proteins investigated. We did, however, find that the ubiquitinated inclusions colocalised with the lysosomal marker, cathepsin D.
D000544:Alzheimer Disease / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000276:immunology* / Q000378:metabolism; D002402:Cathepsin D / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D008247:Lysosomes / Q000378:metabolism / Q000648:ultrastructure; D009135:Muscular Diseases / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D009220:Myositis / Q000276:immunology*; D014452:Ubiquitins / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D014452:Ubiquitins; D002402:Cathepsin D