Acidic and basic fibroblast growth factor-like immunoreactivity in the striatum and midbrain in Huntington's disease

The immunohistochemical localizations of acidic and basic fibroblast growth factor (aFGF and bFGF) were investigated in the striatum and midbrain of Huntington's disease (HD) and control cases using specific antibodies. In the striatum of control cases, the ependymal cell layer was stained for aFGF and bFGF. In addition, a few subependymal astrocytes were positive for aFGF, and some neurons stained weakly for bFGF. In HD striatum, many astrocytes and remaining neurons were strongly stained for aFGF. aFGF-positive astrocytes were particularly conspicuous in the subependymal region of the caudate but appeared throughout the caudate and putamen. The number of bFGF-positive astrocytes was slightly increased. In contrast to the caudate/putamen, the globus pallidus, nucleus of the oculomotor nerve and substantia nigra showed very similar patterns for both aFGF and bFGF in control and most HD brains. Reports that FGF can protect against glutamate neurotoxicity, and that the FGF receptor (FGFR3), with its gene located in the HD region on chromosome 4, appears in striatal neurons, make it tempting to speculate on a possibly important role for FGF-FGFR3 interactions in HD pathology.