First Author | Garden GA | Year | 2002 |
Journal | J Neurosci | Volume | 22 |
Issue | 12 | Pages | 4897-905 |
PubMed ID | 12077187 | Mgi Jnum | J:77530 |
Mgi Id | MGI:2181931 | Doi | 10.1523/JNEUROSCI.22-12-04897.2002 |
Citation | Garden GA, et al. (2002) Polyglutamine-expanded ataxin-7 promotes non-cell-autonomous purkinje cell degeneration and displays proteolytic cleavage in ataxic transgenic mice. J Neurosci 22(12):4897-905 |
abstractText | Spinocerebellar ataxia (SCA) type 7 is an inherited neurodegenerative disorder caused by expansion of a polyglutamine tract within the ataxin-7 protein. To determine the molecular basis of polyglutamine neurotoxicity in this and other related disorders, we produced SCA7 transgenic mice that express ataxin-7 with 24 or 92 glutamines in all neurons of the CNS, except for Purkinje cells. Transgenic mice expressing ataxin-7 with 92 glutamines (92Q) developed a dramatic neurological phenotype presenting as a gait ataxia and culminating in premature death. Despite the absence of expression of polyglutamine-expanded ataxin-7 in Purkinje cells, we documented severe Purkinje cell degeneration in 92Q SCA7 transgenic mice. We also detected an N-terminal truncation fragment of ataxin-7 in transgenic mice and in SCA7 patient material with both anti-ataxin-7 and anti-polyglutamine specific antibodies. The appearance of truncated ataxin-7 in nuclear aggregates correlates with the onset of a disease phenotype in the SCA7 mice, suggesting that nuclear localization and proteolytic cleavage may be important features of SCA7 pathogenesis. The non-cell-autonomous nature of the Purkinje cell degeneration in our SCA7 mouse model indicates that polyglutamine-induced dysfunction in adjacent or connecting cell types contributes to the neurodegeneration. |