title: Amyloid beta protein 42(43) in cerebrospinal fluid of patients with Alzheimer's disease.
abstract: To investigate the pathomechanism of amyloid beta protein (A beta) deposition in brains with Alzheimer's disease (AD), cerebrospinal fluid (CSF) levels of A beta species (CSF-A beta) with different carboxy termini, i.e. A betaX-40 and A betaX-42(43) as well as A beta1-40 and A beta1-42(43), were measured in patients with AD and age-matched controls without dementia (CTR) using sandwich enzyme-linked immunosorbent assays (ELISAs). The present study revealed that both CSF-A betaX-42(43) and A beta1-42(43) levels were significantly lower in the AD patients (P<0.005) than in the CTR group, whereas neither CSF-A betaX-40 nor CSF-A beta1-40 levels showed any differences between the two groups. In addition, although there was no difference between the ratios of A betaX-40 to A beta1-40 in the AD and CTR groups, the ratios of A betaX-42(43) to A beta1-42(43) were increased in the AD group compared with those in the CTR group (P<0.05). Therefore, it can be assumed that the ratios of amino terminal truncations and/or modifications of CSF-A beta42(43) with carboxy termini ending at residue 42(43) were more increased in the AD group than in the CTR group. Increased adsorption of A beta42(43) to A beta deposition in AD brains, decreased secretion of A beta42(43) to CSF and/or increased clearance of A beta42(43) from CSF might explain the diminished levels of A beta42(43) in the CSF of AD patients. In addition, CSF-A beta42(43) could reflect increased amino terminal truncations and/or modifications of A beta42(43) in AD brains.
authors.affiliation: Department of Neurology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tamaoka
authors.forename: N
authors.initials: N
authors.lastname: Sawamura
authors.forename: T
authors.initials: T
authors.lastname: Fukushima
authors.forename: S
authors.initials: S
authors.lastname: Shoji
authors.forename: E
authors.initials: E
authors.lastname: Matsubara
authors.forename: M
authors.initials: M
authors.lastname: Shoji
authors.forename: S
authors.initials: S
authors.lastname: Hirai
authors.forename: Y
authors.initials: Y
authors.lastname: Furiya
authors.forename: R
authors.initials: R
authors.lastname: Endoh
authors.forename: H
authors.initials: H
authors.lastname: Mori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D012737:Sex Factors
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)