APOPTOTIC CELL-DEATH INDUCED BY BETA-AMYLOID(1-42) PEPTIDE IS CELL-TYPE DEPENDENT

beta-Amyloid peptide (A beta), a proteolytic fragment of the beta-amyl oid precursor protein, is a major component of senile plaques in the b rain of Alzheimer's disease patients. This neuropathological feature i s accompanied by increased neuronal cell loss in the brain and there i s evidence that A beta is directly neurotoxic. In the present study re duced cell viability in four different neuroblastoma cell types was ob served after treatment with human A beta(1-42) for 1 day. Of the cell types tested rat PC12 and human IMR32 cells were most susceptible to A beta toxicity. Chromosomal condensation and fragmentation of nuclei w ere seen in PC12, NB(2)a, and B104 cells but not in IMR32 cells irresp ective of their high sensitivity to A beta. Electrophoretic analysis o f cellular DNA confirmed internucleosomal DNA fragmentation typical fo r apoptosis in all cell types except IMR32. These findings suggest tha t the form of A beta-induced cell death (necrosis or apoptosis) may de pend on the cell type.