Distinct regulation of cell cycle and survival in lymphocytes from patients with Alzheimer's disease and amyotrophic lateral sclerosis.

Alterations in cell cycle progression seem to be associated with neuronal death in Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). We previously reported disturbances in the control of cell survival/death fate in immortalized lymphocytes from AD patients. These cell cycle dysfunction and impaired apoptosis were considered systemic manifestations of AD disease. The purpose of this study was to evaluate whether these abnormalities are characteristic of AD, or they may be seen in other neurodegenerative disorders such ALS. Our results indicate that alterations in signaling molecules, Akt and ERK1/2, and in the cyclin-dependent kinase complex inhibitors (CDKis) p21(Cip1) and p27(Kip1) are detectable in lymphoblasts from AD patients, but not in ALS patients, suggesting that these variables may be considered for the development of biomarkers of AD. However, lymphocytes from ALS patients do not represent a useful model to study cell cycle-related events associated with neurodegeneration of motoneurons.