An immunohistochemical study of cathepsin E in Alzheimer-type dementia brains.

We studied the immunohistochemical localization of cathepsin E (cath E) in the brains of patients with Alzheimer disease (AD) and control brains. In the normal brain cathepsin E immunoreactivity was detectable in a small number (below 5%) of neocortical and hippocampal neurons. In AD brains cathepsin E antigen was revealed in most large cortical and hippocampal pyramids and in neurons of the Nuc. basalis of Meynert. Cathepsin E was also present in cerebral microvessels, microglia, and in senile plaques. The enzyme might play roles in the process of neurodegeneration taking place in AD.