title: Soluble pool of Abeta amyloid as a determinant of severity of neurodegeneration in Alzheimer's disease.
abstract: Genetic evidence strongly supports the view that Abeta amyloid production is central to the cause of Alzheimer's disease. The kinetics, compartmentation, and form of Abeta and its temporal relation to the neurodegenerative process remain uncertain. The levels of soluble and insoluble Abeta were determined by using western blot techniques, and the findings were assessed in relation to indices of severity of disease. The mean level of soluble Abeta is increased threefold in Alzheimer's disease and correlates highly with markers of disease severity. In contrast, the level of insoluble Abeta (also a measure of total amyloid load) is found only to discriminate Alzheimer's disease from controls, and does not correlate with disease severity or numbers of amyloid plaques. These findings support the concept of several interacting pools of Abeta, that is, a large relatively static insoluble pool that is derived from a constantly turning over smaller soluble pool. The latter may exist in both intracellular and extracellular compartments, and contain the basic forms of Abeta that cause neurodegeneration. Reducing the levels of these soluble Abeta species by threefold to levels found in normal controls might prove to be a goal of future therapeutic intervention.
authors.affiliation: Department of Pathology, University of Melbourne, Victoria, Australia.
authors.forename: C A
authors.initials: CA
authors.lastname: McLean
authors.forename: R A
authors.initials: RA
authors.lastname: Cherny
authors.forename: F W
authors.initials: FW
authors.lastname: Fraser
authors.forename: S J
authors.initials: SJ
authors.lastname: Fuller
authors.forename: M J
authors.initials: MJ
authors.lastname: Smith
authors.forename: K
authors.initials: K
authors.lastname: Beyreuther
authors.forename: A I
authors.initials: AI
authors.lastname: Bush
authors.forename: C L
authors.initials: CL
authors.lastname: Masters
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D004314:Down Syndrome / Q000378:metabolism / Q000473:pathology; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D009422:Nervous System Diseases / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity; D011699:Putamen / Q000378:metabolism; D012016:Reference Values; D012044:Regression Analysis; D012720:Severity of Illness Index; D012995:Solubility; D013788:Thalamus / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides