Effects of the monomeric, oligomeric, and fibrillar Aβ42 peptides on the proliferation and differentiation of adult neural stem cells from subventricular zone

Abstract

The incidence of amyloid plaques, composed mainly of β-amyloid peptides (Aβ), does not correlate well with the severity of neurodegeneration in patients with Alzheimer's disease (AD). The effects of Aβ42 on neurons or neural stem cells (NSCs) in terms of the aggregated form remain controversial. We prepared three forms of oligomeric, fibrillar, and monomeric Aβ42 peptides and investigated their effects on the proliferation and neural differentiation of adult NSCs, according to the degree of aggregation or concentration. A low micromolar concentration (1 μmol/L) of oligomeric Aβ42 increased the proliferation of adult NSCs remarkably in a neurosphere assay. It also enhanced the neuronal differentiation of adult NSCs and their ability to migrate. These results provide us with valuable information regarding the effects of Aβ42 on NSCs in the brains of patients with AD. © 2007 The Authors.