Abstract

Amyloid-beta peptide plaque in the brain is the primary diagnostic criterion of Alzheimer's disease . The physiological role of Abeta are poorly understood. We have previously determined an Abeta interacting domain in the promoters of AD-associated genes . This AbetaID interacts in a DNA sequence-specific manner with Abeta. We now demonstrate novel Abeta activity as a possible transcription factor. Herein, we detected Abeta-chromatin interaction in cell culture by ChIP assay. We observed that human neuroblastoma cells treated with FITC conjugated Abeta1-40 localized Abeta to the nucleus in the presence of H2O2-mediated oxidative stress. Furthermore, primary rat fetal cerebrocortical cultures were transfected with APP and BACE1 promoter-luciferase fusions, and rat PC12 cultures were transfected with polymorphic APP promoter-CAT fusion clones. Transfected cells were treated with different Abeta peptides and/or H2O2. Abeta treatment of cell cultures produced a DNA sequence-specific response in cells transfected with polymorphic APP clones. Our results suggest the Abeta peptide may regulate its own production through feedback on its precursor protein and BACE1, leading to amyloidogenesis in AD