Decrease of dynamin 2 levels in late-onset Alzheimer's disease alters Abeta metabolism.

Late-onset Alzheimer's disease (LOAD) is significantly associated with a single nucleotide polymorphism located in the dynamin (DNM) 2 gene, especially in non-carriers of the apolipoprotein E-epsilon4 allele. In this study we used real-time PCR to show that DNM2 mRNA is significantly reduced in the cortex of AD brains and in the peripheral blood of dementia patients. Neuroblastoma cells transfected with a dominant negative DNM2 had increased amyloid beta protein (Abeta) secretion and most of the amyloid precursor protein (APP) in these cells was localized to the plasma membrane. In addition, these cells were rich in flotillin, which is a component of lipid rafts. These data suggest that DNM2 expression is reduced in LOAD, which results in the accumulation of APP in lipid raft-rich plasma membranes. Consequently, Abeta secretion may increase in LOAD neurons.