Journal de la maladie d'Alzheimer et du parkinsonisme

Abstrait

Involvement of PKR in Alzheimer's Disease

Jacques Hugon, François Mouton-Liger, Julien Dumurgier, Pauline Lapalus, Magali Prévôt, Sandrine Indart, Jean Louis Laplanche and Claire Paquet

Alzheimer’s disease (AD) is characterized by memory troubles followed by aphasia apraxia and agnosia associated with behavioral disturbances. Neuropathological lesions include senile plaques formed by Aβ peptide, neurofibrillary tangles made of hyperphosphorylated tau and neuronal loss. The cause of AD is unknown but Aβ peptide could be responsible for neuronal degeneration. PKR is a stress and pro-apoptotic kinase that controls protein translation via the phosphorylation of the eukariotic initiation factor 2α (eIF2α). Activated PKR accumulates in affected neurons in AD brains and the phosphorylation of PKR can be induced by Aβ peptide. We have found increased levels of PKR in the cerebrospinal fluid of AD patients and PKR level is a good predictor of the cognitive decline. In addition PKR can modulate the levels of BACE1, an APP cleaving enzyme, and can influence tau phosphorylation. Altogether, PKR represents a potential new biomarker and a valid new therapeutic target for neuroprotection in AD.