S. Koyano et al., Neuronal intranuclear inclusions in spinocerebellar ataxia type 2: triple-labeling immunofluorescent study, NEUROSCI L, 273(2), 1999, pp. 117-120
Spinocerebellar ataxia type 2 (SCA2) is associated with an expansion of CAG
/polyglutamine-repeat of a gene of unknown function. We performed an immuno
histochemical study to identify the immunolocalization of the disease prote
in ataxin-2 in normal and SCA2 patients. Although normal and expanded ataxi
n-2 were ubiquitously localized to the cytoplasm of neurons, ubiquitinated
intranuclear inclusions were observed selectively in 1-2% of neurons of aff
ected brain regions except the cerebellum. Triple-labeling immunofluorescen
ce revealed that ataxin-2, expanded polyglutamine and ubiquitin were coloca
lized to these neuronal intranuclear inclusions (Nls), indicating that SCA2
shares morphological characteristics common to other neurological disorder
s associated with an expansion of CAG/polyglutamine-repeat. Lack of Nls in
the cerebellar lesion, however, suggests the discrepancy between formation
of Nls and neuronal degeneration in SCA2. (C) 1999 Elsevier Science Ireland
Ltd. All rights reserved.