Glycogen synthase kinase-3 is increased in white cells early in Alzheimer's disease

Alzheimer's disease (AD) is a disorder without a molecular marker in peripheral tissues or a disease modifying treatment. As increasing evidence has suggested a role for glycogen synthase kinase-3 (GSK-3) in the pathogenesis of the condition we measured total GSK-3 protein (alpha and beta isoforms) and GSK-3 activity (serine 9 phosphorylation) in a group of healthy elderly people, in AD and in mild cognitive impairment (MCI). Total GSK-3 protein was increased in both AD and in MCI without a compensatory decrease in activity. These data suggest that GSK-3 assays might be a useful diagnostic marker in a readily available tissue and moreover that GSK-3 activity is increased in the prodromal phase of the disorder suggesting that inhibition of GSK-3 might be a useful therapeutic strategy.