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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-10-20
pubmed:abstractText
Human beta-amyloid precursor protein (APP) transgenic mice are commonly used to test potential therapeutics for Alzheimer's disease. We have characterized the dynamics of beta-amyloid (Abeta) generation and deposition following gamma-secretase inhibition with compound LY-411575 [N(2)-[(2S)-2-(3,5-difluorophenyl)-2-hydroxyethanoyl]-N(1)-[(7S)-5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl]-L-alaninamide]. Kinetic studies in preplaque mice distinguished a detergent-soluble Abeta pool in brain with rapid turnover (half-lives for Abeta40 and Abeta42 were 0.7 and 1.7 h) and a much more stable, less soluble pool. Abeta in cerebrospinal fluid (CSF) reflected the changes in the soluble brain Abeta pool, whereas plasma Abeta turned over more rapidly. In brain, APP C-terminal fragments (CTF) accumulated differentially. The half-lives for gamma-secretase degradation were estimated as 0.4 and 0.1 h for C99 and C83, respectively. Three different APP transgenic lines responded very similarly to gamma-secretase inhibition regardless of the familial Alzheimer's disease mutations in APP. Amyloid deposition started with Abeta42, whereas Abeta38 and Abeta40 continued to turn over. Chronic gamma-secretase inhibition lowered amyloid plaque formation to a different degree in different brain regions of the same mice. The extent was inversely related to the initial amyloid load in the region analyzed. No evidence for plaque removal below baseline was obtained. gamma-Secretase inhibition led to a redistribution of intracellular Abeta and an elevation of CTFs in neuronal fibers. In CSF, Abeta showed a similar turnover as in preplaque animals demonstrating its suitability as marker of newly generated, soluble Abeta in plaque-bearing brain. This study supports the use of APP transgenic mice as translational models to characterize Abeta-lowering therapeutics.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1521-0103
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
327
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
411-24
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Dynamics of Abeta turnover and deposition in different beta-amyloid precursor protein transgenic mouse models following gamma-secretase inhibition.
pubmed:affiliation
Novartis Institutes for BioMedical Research, Basel, Switzerland.
pubmed:publicationType
Journal Article