Format

Send to

Choose Destination
J Alzheimers Dis. 2012;31(1):167-76. doi: 10.3233/JAD-2012-120328.

Stress hormone leads to memory deficits and altered tau phosphorylation in a model of Alzheimer's disease.

Author information

1
Center for Translational Medicine, Temple University, School of Medicine, Philadelphia, PA 19140, USA.

Abstract

Several studies have linked stress with Alzheimer's disease (AD) vulnerability; however, the mechanism remains to be fully elucidated. In the current paper, we investigated the role of glucocortitcoids on the AD-like phenotype. We administered the glucocorticoid dexamethasone to Tg2576 mice for 4 weeks and then investigated its effect on memory, amyloid-β and tau levels, and metabolism. At the end of the treatment period, we observed that mice receiving dexamethasone had a significant impairment in the fear conditioning paradigm compared with controls. Dexamethasone-treated animals showed a significant increase in the amount of brain soluble Aβ40 levels, but no alteration in the steady state levels of its precursor protein, AβPP, or in the major protease enzymes involved in its metabolism (i.e., ADAM-10, BACE-1, or γ-secretase complex). While total tau protein levels were unaltered between the two groups, we found that dexamethasone significantly reduced tau phosphorylation at specific sites that were mediated by decreases in glycogen synthase kinase-3β protein level activity. Finally, we observed a direct correlation between memory impairments and tau phosphorylation levels. Our study highlights the significant role that glucocorticoids play in exacerbating AD-like cognitive impairments via alteration of tau protein phosphorylation state.

PMID:
22531419
PMCID:
PMC3882896
DOI:
10.3233/JAD-2012-120328
[Indexed for MEDLINE]
Free PMC Article

Publication type, MeSH terms, Substances, Grant support

Supplemental Content

Full text links

Icon for IOS Press Icon for PubMed Central
Loading ...
Support Center