Neuronal cell death is preceded by cell cycle events at all stages of Alzheimer's disease

Y Yang, EJ Mufson, K Herrup - Journal of Neuroscience, 2003 - Soc Neuroscience
Y Yang, EJ Mufson, K Herrup
Journal of Neuroscience, 2003Soc Neuroscience
Cell cycle events play a major role in the loss of neurons in advanced Alzheimer's disease
(AD). It is currently unknown, however, whether the same is true for the neuronal losses in
early disease stages. To explore this issue we analyzed brain autopsy material from
individuals clinically categorized with mild cognitive impairment (MCI), many if not most of
whom will progress to AD. Immunocytochemistry for three cell cycle-related proteins,
proliferating cell nuclear antigen, cyclin D, and cyclin B, was performed on sections from …
Cell cycle events play a major role in the loss of neurons in advanced Alzheimer's disease (AD). It is currently unknown, however, whether the same is true for the neuronal losses in early disease stages. To explore this issue we analyzed brain autopsy material from individuals clinically categorized with mild cognitive impairment (MCI), many if not most of whom will progress to AD. Immunocytochemistry for three cell cycle-related proteins, proliferating cell nuclear antigen, cyclin D, and cyclin B, was performed on sections from hippocampus, basal nucleus of Meynert, and entorhinal cortex. The results obtained from MCI cases were compared with material from individuals diagnosed with AD and those without cognitive impairment. In both hippocampus and basal nucleus, there was a significant percentage of cell cycle immunopositive neurons in the MCI cases. These percentages were similar to those found in the AD cases but significantly higher than non-cognitively impaired controls. In entorhinal cortex, the density of cell cycle-positive neurons was greater in MCI than in AD. However, we observed large variations in the percentages of immunopositive neurons from individual to individual. These findings lend support to the hypothesis that both the mechanism of cell loss (a cell cycle-induced death) and the rate of cell loss (a slow atrophy over several months) are identical at all stages of the AD disease process. The implication of the findings for human clinical trials is discussed.
Soc Neuroscience