Characterization and expression of presenilin 1 in mouse brain

The expression pattern of presenilin 1 (PS-1) in adult mouse brain was investigated using antibodies to specific peptides of PS-1. One antibody, Alz14A, specifically detected a 53 kDa protein in retinoic acid-treated P19 cells and mouse brain protein extracts consistent with the predicted PS-1 molecular weight. Immunohistochemical staining revealed that PS-1 was localized predominantly in large neurons in areas that were known to be affected by Alzheimer disease (AD) such as the hippocampal formation, entorhinal cortex and the subiculum. Selected neurons in other regions not known to be directly affected by AD, such as thalamic nuclei, Purkinje cells, large neurons in the brainstem and the gray matter of the spinal cord, and the dorsal root ganglion, also expressed PS-1. These observations suggest that other as yet identified factors might interact with mutated presenilins to cause neurodegeneration in AD-affected areas.