title: Iron is a specific cofactor for distinct oxidation- and aggregation-dependent Aβ toxicity mechanisms in a Drosophila model.
abstract: Metals, including iron, are present at high concentrations in amyloid plaques in individuals with Alzheimer's disease, where they are also thought to be cofactors in generating oxidative stress and modulating amyloid formation. In this study, we present data from several Drosophila models of neurodegenerative proteinopathies indicating that the interaction between iron and amyloid beta peptide (Aβ) is specific and is not seen for other aggregation-prone polypeptides. The interaction with iron is likely to be important in the dimerisation of Aβ and is mediated by three N-terminal histidines. Transgenic fly lines systematically expressing all combinations of His>Ala substitutions in Aβ were generated and used to study the pathological role of these residues. Developmental eye phenotypes, longevity and histological examinations indicate that the N-terminal histidines have distinct position-dependent and -independent mechanisms. The former mediate the toxic effects of metals and Aβ aggregation under non-oxidising conditions and the latter are relevant under oxidising conditions. Understanding how Aβ mediates neurotoxic effects in vivo will help to better target pathological pathways using aggregation blockers and metal-modifying agents.
authors.affiliation: Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Ott
authors.affiliation: Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Dziadulewicz
authors.affiliation: Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK MedImmune Limited, Aaron Klug Building, Granta Park, Cambridge CB21 6GH, UK dcc26@cam.ac.uk.
authors.forename: Damian C
authors.initials: DC
authors.lastname: Crowther
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D019943:Amino Acid Substitution; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D004195:Disease Models, Animal; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005293:Ferritins / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D007501:Iron / Q000378:metabolism*; D010084:Oxidation-Reduction; D010641:Phenotype; D066329:Protein Aggregates; D066263:Protein Aggregation, Pathological / Q000209:etiology / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D066329:Protein Aggregates; D011994:Recombinant Proteins; D006639:Histidine; D005293:Ferritins; D007501:Iron
keywords: Alzheimer's disease; Amyloid beta peptide; Drosophila; Iron; Metal; Oxidative stress