Project description:FK506 binding protein 51kDa (FKBP51/FKBP5) is part of a mature heat shock protein 90kDa (Hsp90) chaperone complex that preserves tau. Microarray analysis of human brains reveal that FKBP51 gene expression selectively increased with age and Alzheimer's disease, which correlated with demethylation of the regulatory regions in the FKBP5 gene. Moreover, FKBP51 levels significantly correlated with Braak pathological staging. In addition, we show that in brains devoid of FKBP51, tau levels are reduced. Recombinant FKBP51 and Hsp90 synergize to block tau clearance through the proteasome and produce T22-positive tau oligomers. Overexpression of FKBP51 in a tau transgenic mouse model revealed that FKBP51 preserved tau species, including phosphorylated and oligomeric tau that have been linked to Alzheimer's disease pathogenesis. FKBP51 blocked amyloid formation and decreased tangle load in the brain. These alterations in tau turnover and aggregate structure culminated in enhanced neurotoxicity. We propose a model where age-associated increases in FKBP51 levels can out-compete the association of other pro-degradation Hsp90 co-chaperones, resulting in neurotoxic tau accumulation. Thus, strategies aimed at attenuating FKBP51 levels or its interaction with Hsp90 could be therapeutically relevant for Alzheimer's disease and other tauopathies. These AD cases were processed simultaneously with the control cases (young and aged) included in GSE11882 Postmortem brain tissue was collected from ADRC brain banks. Cases were preferentially selected where 3 or more brain regions were available
Project description:The R47H variant of TREM2 is associated with higher risk of Alzheimer's disease. We generated mice expressing the common variant or R47H variant of human TREM2 in the absence of murine TREM2 on the 5XFAD mouse model of Alzheimer's disease.
Project description:To identify molecular pathological alterations in AD brains, we performed interspecies comparative microarray analyses using RNAs prepared from postmortem human brain tissues donated for the Hisayama study and hippocampal RNAs from the triple-transgenic mouse model of AD (3xTg-AD) Three-way ANOVA of microarray data from frontal cortex, temporal cortex and hippocampus with presence/absence of AD and vascular dementia, and sex, as factors revealed that the gene expression profile is most significantly altered in the hippocampi of AD brains. Comparative analyses of the brains of AD patients and a mouse model of AD showed that genes involved in non-insulin dependent DM and obesity were significantly altered in both, as were genes related to psychiatric disorders and Alzheimer’s disease.
Project description:To identify molecular pathological alterations in AD brains, we performed interspecies comparative microarray analyses using RNAs prepared from postmortem human brain tissues donated for the Hisayama study and hippocampal RNAs from the triple-transgenic mouse model of AD (3xTg-AD) Three-way ANOVA of microarray data from frontal cortex, temporal cortex and hippocampus with presence/absence of AD and vascular dementia, and sex, as factors revealed that the gene expression profile is most significantly altered in the hippocampi of AD brains. Comparative analyses of the brains of AD patients and a mouse model of AD showed that genes involved in non-insulin dependent DM and obesity were significantly altered in both, as were genes related to psychiatric disorders and Alzheimer’s disease.
Project description:Microarray analysis on human neuroblastoma cells exposed to iron, B-amyloid or the B-amyloid iron complex. Alzheimer's disease is associated with an abnormal accumulation of certain metal ions.
Project description:Reactive astrogliosis is a well-known and recognised marker of Alzheimer's Disease (AD). The aim of this study is to functionally visualise reactive astrocyte-mediated neuronal hypometabolism in the brains that is associated with AD and neuroinflammation. To investigate alterations of acetate and glucose metabolism and the effect thereof in AD-like astrocytes, primary astrocyte cultures were treated with acetate in the presence or absence of amyloid beta (Aβ) oligomers. On comparison, we found that acetate treatment upregulated the expression of acetate transporter MCT1 (Slc16a1) as well as that of enzymes involved in the urea cycle and subsequent GABA synthesis. We could, therefore, conclude that MCT1-mediated uptake of acetate into astrocytes triggered GABA synthesis by upregulating enzymes involved in putrescine production and degradation.
Project description:Here we analyze the gene expression and chromatin accessibility landscape of immune cells in the brains of 5XFAD mice, a common model of Alzheimer's disease, bearing knock-in of human APOE variants in the mouse APOE locus, and aged to 10, 20, 60, or 96 weeks of age.