Activated mTOR and PKR kinases in lymphocytes correlate with memory and cognitive decline in Alzheimer's disease

Background: The control of translation, involving the kinases mTOR ( mammalian target of rapamycin) and PKR (double-stranded RNA-dependent protein kinase), modulates cell survival and death and is altered in the brains of patients with Alzheimer's disease ( AD). In AD increased susceptibility of lymphocytes to apoptosis has been reported. Methods: We investigated the level of the kinases mTOR and PKR and the eukaryotic initiation factor 2 alpha (eIF2 alpha) in lymphocytes of patients with AD in comparison with controls. In AD patients we also looked for a correlation between activated proteins and cognitive and memory tests. Results: We report significant alterations of the levels of these kinases and eIF2 alpha in lymphocytes of AD patients that were also significantly correlated with cognitive and memory test scores. Conclusion: These results suggest that the levels of mTOR, PKR and eIF2 alpha in lymphocytes could follow the cognitive decline in AD. Copyright (C) 2006 S. Karger AG, Basel.