Amyloid beta protein-induced zinc sequestration leads to synaptic loss via dysregulation of the ProSAP2/Shank3 scaffold.
Mol Neurodegener
; 6: 65, 2011 Sep 22.
Article
em En
| MEDLINE
| ID: mdl-21939532
ABSTRACT
BACKGROUND:
Memory deficits in Alzheimer's disease (AD) manifest together with the loss of synapses caused by the disruption of the postsynaptic density (PSD), a network of scaffold proteins located in dendritic spines. However, the underlying molecular mechanisms remain elusive. Since it was shown that ProSAP2/Shank3 scaffold assembly within the PSD is Zn2+-dependent and that the amyloid beta protein (Aß) is able to bind Zn2+, we hypothesize that sequestration of Zn2+ ions by Aß contributes to ProSAP/Shank platform malformation.RESULTS:
To test this hypothesis, we designed multiple in vitro and in vivo assays demonstrating ProSAP/Shank dysregulation in rat hippocampal cultures following Aß oligomer accumulation. These changes were independent from alterations on ProSAP/Shank transcriptional level. However, application of soluble Aß prevented association of Zn2+ ions with ProSAP2/Shank3 in a cell-based assay and decreased the concentration of Zn2+ clusters within dendrites. Zn2+ supplementation or saturation of Aß with Zn2+ ions prior to cell treatment was able to counter the effects induced by Aß on synapse density and ProSAP2/Shank3 levels at the PSD. Interestingly, intracellular Zn2+ levels in APP-PS1 mice and human AD hippocampus are reduced along with a reduction in synapse density and synaptic ProSAP2/Shank3 and Shank1 protein levels.CONCLUSIONS:
We conclude that sequestration of Zn2+ ions by Aß significantly contributes to changes in ProSAP2/Shank3 platforms. These changes in turn lead to less consolidated (mature) synapses reflected by a decrease in Shank1 protein levels at the PSD and decreased synapse density in hippocampal neurons.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article