Department of Neurology, School of Medicine Chiba University, Japan.
The localization of mRNA of interferon-alpha (IFNA21) was examined in human brain tissues from neurologically normal, Parkinson's and Alzheimer's disease (AD) cases, using an in situ hybridization method. In all cases, signals for the mRNA of IFNA21 were detected in the white matter microglial cells. In AD brains, a few neurons in the parietal lobe were intensely labeled. These results suggest that one type of IFN-alpha protein is constitutively expressed in white matter microglial cells, and that expression of IFN-alpha in neuronal cells may play some role in AD pathology.