INDUCTION OF BETA-AMYLOID PRECURSOR PROTEIN ISOFORM MESSENGER-RNAS BY BFGF IN ASTROCYTES

ALL three major transcripts of beta-amyloid precursor protein (APP) were expressed in astrocytes. The ratio for APP695, APP751 and APP770 isoform mRNAs being 1:4:2. Treatment with bFGF and EGF produced upregulation of APP mRNAs in cultured astrocytes in varying proportions. In comparison with controls, increases in APP mRNAs in bFGF and EGF treated groups were about 4.5 and 2 fold, respectively. The elevation in mRNAs of KPI-containing isoforms APP751 and APP770 was relatively more than the elevation in mRNA of APP695 isoform. Our findings provide further evidence for the involvement of astrocytes in a cascade of events leading to the development of senile plaques in Alzheimer's disease and Down's syndrome.