title: Redox factor-1 in muscle biopsies of patients with inclusion-body myositis.
abstract: To determine whether redox factor-1 (Ref-1) participates in the pathogenesis of inclusion-body myositis (IBM), we immunolocalized Ref-1 in muscle biopsies of IBM patients by light- and electron-microscopy. Approximately 70-80% of the IBM vacuolated muscle fibers had focal inclusions strongly immunoreactive for Ref-1. By immunoelectronmicroscopy, Ref-1 was localized to paired-helical filaments, 6-10 nm amyloid-like fibrils and amorphous material. Virtually all regenerating and necrotic muscle fibers in various muscle biopsies had diffusely strong Ref-1 immunoreactivity. At all neuromuscular junctions, postsynaptically there was strong Ref-1 immunoreactivity. Our study suggests that Ref-1 plays a role in IBM pathogenesis, and in other pathologic and normal processes of human muscle.
authors.affiliation: USC Neuromuscular Center, Department of Neurology, University of Southern California Keck School of Medicine, Good Samaritan Hospital, Los Angeles, CA 90017-1912, USA.
authors.forename: A
authors.initials: A
authors.lastname: Broccolini
authors.forename: W K
authors.initials: WK
authors.lastname: Engel
authors.forename: R B
authors.initials: RB
authors.lastname: Alvarez
authors.forename: V
authors.initials: V
authors.lastname: Askanas
mesh_terms: D001706:Biopsy; D019757:Carbon-Oxygen Lyases / Q000032:analysis*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D006801:Humans; D016253:Microscopy, Immunoelectron; D018482:Muscle, Skeletal / Q000473:pathology* / Q000648:ultrastructure; D018979:Myositis, Inclusion Body / Q000473:pathology*
chemical_list: D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase