Programmed cell death (apoptosis) in Alzheimer's disease and Creutzfeldt-Jakob disease

The aim of our study was the estimation of the apoptosis process using in situ-end labelling of DNA breaks method on paraffin sections in 5 human cases of Alzheimer's disease (AD), 6 of Creutzfeldt-Jakob disease (CJD) and in 25 mice infected experimentally with the Fujisaki strain of CJD, killed sequentially at one-week intervals. The numbers of apoptotic cells in CJD-infected mice in the later stages of the disease and in terminally ill mice were progressively higher that at the early stage of the disease. Further, we found a correlation between the intensity of apoptosis and major lesions hallmark of disease--the intensity of spongiform changes in the cerebral cortex but not in the accumulation of PrP in CJD infected mice. The number of A beta-amyloid plaques in AD was not related to apoptotic index. Our study showed that apoptosis is a very important event in these neurodegenerative diseases and may become a basic mechanism in loss of neurons.