Acidic FGF expression in the surroundings of senile plaques.

Immunohistochemical examination of postmortem brain tissue of Alzheimer's disease revealed that acidic fibroblast growth factor (aFGF) was specifically expressed in a subpopulation of reactive astrocytes which were congregated at the margin of the senile plaque. Double immunostaining indicated that such upregulation of aFGF expression might be related to the presence of reactive microglia rather than beta-amyloid protein deposits. Although, on the other hand, immunohistochemical staining for fibroblast growth factor receptor-1 occurred in some cortical neurons of Alzheimer's disease, the staining pattern did not differ from that in age-matched controls. Possible significance of aFGF-positive astrocytes in the surroundings of the senile plaque will be discussed in relation to receptor mediated or non-mediated mechanisms.