New advances in inclusion-body myositis.
The major new advances in seeking the pathogenic mechanisms of sporadic inclusion-body myositis and hereditary inclusion-body myopathy are discussed. Hypotheses are presented regarding the possible causes and significance of amyloid deposits in sporadic inclusion-body myositis and the roles of abnormally accumulated ubiquitin, beta-amyloid protein, beta-amyloid precursor protein, alpha 1-antichymotrypsin, hyperphosphorylated tau, and prion protein in the vacuolated muscle fibers in both sporadic inclusion-body myositis and hereditary inclusion-body myopathy. Because hereditary inclusion-body myopathy is virtually free of Congophilic amyloid deposits but, like sporadic inclusion-body myositis, contains large accumulations of beta-amyloid protein, it is possible that the lesions in hereditary inclusion-body myopathy may represent "early" changes. There are striking similarities between the pathology of inclusion-body myositis muscle and brains affected by Alzheimer's disease in regard to accumulation of ubiquitin, beta-amyloid protein and its precursor protein, alpha 1-antichymotrypsin, and hyperphosphorylated tau.
Askanas
V
V
University of Southern California School of Medicine, Los Angeles.
Engel
W K
WK
D000682:Amyloid / Q000032:analysis; D006801:Humans; D002479:Inclusion Bodies / Q000737:chemistry*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009132:Muscles / Q000648:ultrastructure; D017285:Polymyositis / Q000150:complications / Q000235:genetics / Q000473:pathology*; D014452:Ubiquitins / Q000032:analysis; D000514:alpha 1-Antichymotrypsin / Q000032:analysis
D000682:Amyloid; D014452:Ubiquitins; D000514:alpha 1-Antichymotrypsin