Amyloid beta protein and its 3-kDa fragment are present in the axoplasm fraction of the white matter in human brain.
Production of the soluble amyloid beta-protein (A beta) precedes abnormal accumulation of A beta amyloid in the brains of subjects with Alzheimer's disease. To determine the cellular source and generating mechanisms of soluble A beta in the human brain, we separated an axoplasm fraction from the cerebral white matter and analyzed it. The axoplasm fraction contained secretory isoforms of beta-amyloid precursor protein (APP) and 11.5 kDa A beta-bearing carboxyl-terminal fragments (CTFs) of APP. Furthermore, soluble 4 kDa A beta and 3 kDa fragments of A beta (p3) were obtained from the axoplasm fraction. These results suggest that amyloidogenic 4 kDa A beta is intracellularly produced in cerebral neurons and carried through the axons in human brain.
Tokuda
T
T
Department of Medicine (Neurology), Shinshu University School of Medicine, Matsumoto, Japan.
Kametani
F
F
Tanaka
K
K
Sahara
N
N
Ikeda
S
S
Yanagisawa
N
N
D000368:Aged; D016229:Amyloid beta-Peptides / Q000032:analysis*; D001369:Axons / Q000737:chemistry* / Q000473:pathology / Q000648:ultrastructure; D001921:Brain / Q000473:pathology*; D001923:Brain Chemistry; D003600:Cytosol / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000473:pathology*; D010446:Peptide Fragments / Q000032:analysis*; D012016:Reference Values
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments