biostudies-literatureEverett JNCRR NIH HHSNIMHD NIH HHSAlzheimer's AssociationUniversity of WarwickEngineering and Physical Sciences Research CouncilUniversity of Texas at San Antonio11782-11796https://www.ebi.ac.uk/biostudies/studies/S-EPMC6034173biostudies-literatureUnknown10(25)Altered metabolism of biometals in the brain is a key feature of Alzheimer's disease, and biometal interactions with amyloid-β are linked to amyloid plaque formation. Iron-rich aggregates, including evidence for the mixed-valence iron oxide magnetite, are associated with amyloid plaques. To test the hypothesis that increased chemical reduction of iron, as observed in vitro in the presence of aggregating amyloid-β, may occur at sites of amyloid plaque formation in the human brain, the nanoscale distribution and physicochemical states of biometals, particularly iron, were characterised in isolated amyloid plaque cores from human Alzheimer's disease cases using synchrotron X-ray spectromicroscopy. In situ X-ray magnetic circular dichroism revealed the presence of magnetite: a finding supporteNanoscaleNanoscale synchrotron X-ray speciation of iron and calcium compounds in amyloid plaque cores from Alzheimer's disease subjects.PMC6034173EP/N033191/1- EP/N033140/1G12MD007591EP/K035193/117458075G12RR013646AARFD-17-529742EP/N033191/1G12 RR013646EP/N033140/1G12 MD007591Everett JLermyte FDobson JPerry GTjendana-Tjhin VTelling NDHands-Portman ICollingwood JFPlascencia-Villa GBrooks JfalseNanoscale synchrotron X-ray speciation of iron and calcium compounds in amyloid plaque cores from Alzheimer's disease subjects.Altered metabolism of biometals in the brain is a key feature of Alzheimer's disease, and biometal interactions with amyloid-β are linked to amyloid plaque formation. Iron-rich aggregates, including evidence for the mixed-valence iron oxide magnetite, are associated with amyloid plaques. To test the hypothesis that increased chemical reduction of iron, as observed in vitro in the presence of aggregating amyloid-β, may occur at sites of amyloid plaque formation in the human brain, the nanoscale distribution and physicochemical states of biometals, particularly iron, were characterised in isolated amyloid plaque cores from human Alzheimer's disease cases using synchrotron X-ray spectromicroscopy. In situ X-ray magnetic circular dichroism revealed the presence of magnetite: a finding supporte2018-01-01T00:00:00Z2018 Jul2026-07-15T19:38:04.725Z2026-07-09T03:07:38.112ZS-EPMC60341732968824010.1039/c7nr06794a