An iron-export ferroxidase activity of β-amyloid protein precursor is inhibited by zinc in Alzheimer’s Disease

An iron-export ferroxidase activity of β-amyloid protein precursor is inhibited by zinc in Alzheimer’s Disease

Alzheimer’s Disease (AD) is complicated by pro-oxidant intraneuronal Fe 2+ elevation as well as extracellular Zn 2+ accumulation within amyloid plaque. We found that the AD β-amyloid protein precursor (APP) possesses ferroxidase activity mediated by a conserved H-ferritin-like active site, which is...

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Bibliographic Details
Published in:Cell 2010-09, Vol.142 (6), p.857-867
Main Authors: Duce, James A., Tsatsanis, Andrew, Cater, Michael A., James, Simon A., Robb, Elysia, Wikhe, Krutika, Leong, Su Ling, Perez, Keyla, Johanssen, Timothy, Greenough, Mark A., Cho, Hyun-Hee, Galatis, Denise, Moir, Robert D., Masters, Colin L., McLean, Catriona, Tanzi, Rudolph E., Cappai, Roberto, Barnham, Kevin J., Ciccotosto, Giuseppe D., Rogers, Jack T., Bush, Ashley I.
Format: Article
Language:eng
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Summary:Alzheimer’s Disease (AD) is complicated by pro-oxidant intraneuronal Fe 2+ elevation as well as extracellular Zn 2+ accumulation within amyloid plaque. We found that the AD β-amyloid protein precursor (APP) possesses ferroxidase activity mediated by a conserved H-ferritin-like active site, which is inhibited specifically by Zn 2+ . Like ceruloplasmin, APP catalytically oxidizes Fe 2+ , loads Fe 3+ into transferrin, and has a major interaction with ferroportin in HEK293T cells (that lack ceruloplasmin) and in human cortical tissue. Ablation of APP in HEK293T cells and primary neurons induces marked iron retention, whereas increasing APP695 promotes iron export. Unlike normal mice, APP−/− mice are vulnerable to dietary iron exposure, which causes Fe 2+ accumulation and oxidative stress in cortical neurons. Paralleling iron accumulation, APP ferroxidase activity in AD post-mortem neocortex is inhibited by endogenous Zn 2+ , which we demonstrate can originate from Zn 2+ -laden amyloid aggregates and correlates with Aβ burden. Abnormal exchange of cortical zinc may link amyloid pathology with neuronal iron accumulation in AD.
ISSN:0092-8674
1097-4172