Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-9-22
pubmed:abstractText
Although much maligned, the amyloid-beta (Abeta) protein has been shown to possess a number of trophic properties that emanate from the protein's ability to bind Cu, Fe and Zn. Abeta belongs to a group of proteins that capture redox metal ions (even under mildly acidotic conditions), thereby preventing them from participating in redox cycling with other ligands. The coordination of Cu appears to be crucial for Abeta's own antioxidant activity that has been demonstrated both in vitro as well as in the brain, cerebrospinal fluid and plasma. The chelation of Cu by Abeta would therefore be predicted to dampen oxidative stress in the mildly acidotic and oxidative environment that accompanies acute brain trauma and Alzheimer's disease (AD). Given that oxidative stress promotes Abeta generation, the formation of diffuse amyloid plaques is likely to be a compensatory response to remove reactive oxygen species. This review weighs up the evidence supporting both the trophic and toxic properties of Abeta, and while evidence for direct Abeta neurotoxicity in vivo is scarce, we postulate that the product of Abeta's antioxidant activity, hydrogen peroxide (H(2)O(2)), is likely to mediate toxicity as the levels of this oxidant rise with the accumulation of Abeta in the AD brain. We propose that metal ion chelators, antioxidants, antiinflammatories and amyloid-lowering drugs that target the reduction of H(2)O(2) and/or Abeta generation may be efficacious in decreasing neurotoxicity. However, given the antioxidant activity of Abeta, we suggest that the excessive removal of Abeta may prevent adequate chelation of metal ions and removal of O(2)(-z.ccirf;), leading to enhanced, rather than reduced, neuronal oxidative stress.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:author
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-16
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Amyloid-beta: a chameleon walking in two worlds: a review of the trophic and toxic properties of amyloid-beta.
pubmed:affiliation
Institute of Pathology, Case Western Reserve University, 2085 Adelbert Road, Cleveland, OH 44106, USA. csa4@po.cwru.edu
pubmed:publicationType
Journal Article, Review