Factors influencing the expression of A beta PP/APLP in glial cells

The abnormal processing of the amyloid beta precursor protein (A beta PP) t o generate the neurotoxic 40-42 amino acid A beta peptide is a pivotal even t in the early stages of Alzheimer's disease (AD). Therefore, factors that control A beta PP expression, and its amyloid precursor-like protein (APLP) homologue, would be expected to influence A beta generation and the associ ated neural cell death. Both hydrogen peroxide (with associated free radica l production) and exposure to hypoxia significantly decreased the expressio n of A beta PP/APLP in glial cells. In contrast, however, the glucocorticoi d dexamethasone increased cellular A beta PP/APLP levels. These results dem onstrate that the control of A beta PP/APLP expression is multifactorial an d agents that have been proposed to play a role in the early stages of AD c an influence A beta PP/APLP levels.