Prominent expression of presenilin-1 in senile plaques and reactive astrocytes in Alzheimer's disease brain.

Mutations in the presenilin 1 (PS-1) gene account for most cases of autosomal dominant early-onset familial Alzheimer's disease (AD). In order to elucidate the cellular expression profile of PS-1 we used a novel N-terminal monoclonal antibody against human PS-1. Immunohistochemical staining was observed strongly in senile plaques, and reactive astrocytes of gray and white matter. Neuronal immunoreactivity, however, was found to be only moderate. RT-PCR analysis of PS-1 mRNA revealed expression throughout human development as well as in human glioma cell lines. Altered PS-1 function may contribute to plaque formation in AD.