title: [beta-amyloid cascade: current status and future directions].
abstract: The deposition of amyloid beta peptides (A beta) is one of the pathological hallmarks of Alzheimer's disease (AD) brains. A beta are composed of 40-42 amino acid peptides that are proteolytically cleaved from beta APP. The deposition as diffuse plaques of a species of A beta ending at the 42nd residue (A beta 42) is one of the earliest pathological changes of AD. Importantly, mutations in beta APP genes located in positions flanking the A beta sequences have been shown to cosegregate with the clinical manifestations of AD in a subset of familial AD (FAD) pedigrees. Moreover, mutations in presenilin (PS) 1 and 2, novel polytopic membrane proteins identified as causative molecules for the majority of FAD, also increase the production of A beta 42. These results support the notion that A beta (42) plays a key role in the cascadic development of AD. Recently, PS 1 and PS 2 are shown to be the catalytic subunits of gamma-secretase that cleave the intramembrane segments of beta APP and Notch. Future therapeutic approaches to reduce amyloid deposition, including inhibitors for beta- and gamma-secretases, as well as beta-amyloid vaccine therapy, raise high hopes towards the cure and prevention of AD, although the outcome thereof would be key to the consistency of amyloid cascade hypothesis.
authors.affiliation: Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, University of Tokyo.
authors.forename: T
authors.initials: T
authors.lastname: Iwatsubo
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology* / Q000628:therapy; D053829:Amyloid Precursor Protein Secretases; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D016282:Aspartic Acid Endopeptidases; D010450:Endopeptidases / Q000502:physiology; D006801:Humans; D016233:Immunotherapy, Active; D008565:Membrane Proteins / Q000235:genetics; D009154:Mutation; D010446:Peptide Fragments / Q000378:metabolism; D053764:Presenilin-1; D053766:Presenilin-2
chemical_list: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D008565:Membrane Proteins; C508853:PSEN1 protein, human; C508861:PSEN2 protein, human; D010446:Peptide Fragments; D053764:Presenilin-1; D053766:Presenilin-2; C092862:amyloid beta-protein (10-43); D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human