Presence of BACE1 and BACE2 in muscle fibres of patients with sporadic inclusion-body myositis

Sporadic inclusion-body myositis (IBM) is the most common, progressive musc le disease of older Individuals. We Investigated the presence of BACE1 and BACE2-two beta secretases that cleave amyloid-beta -precursor protein-in mu scle-biopsy samples from patients with IBM and from controls. On immunofluo rescence, BACE1 and BACE2 co-localised with amyloid beta in IBM vacuolated muscle fibres, but were not found In controls. Immunoblotting showed Increa sed BACE2 but not BACE1 in patients with IBM compared with controls. Our st udy suggests that both of these proteases might participate In processing o f amyloid-beta -precursor protein in IBM muscle fibres.