Glial S100B protein modulates mutant ataxin-1 aggregation and toxicity: TRTK12 peptide, a potential candidate for SCA1 therapy.

Non-cell autonomous involvement of glial cells in the pathogenesis of polyglutamine diseases is gaining recognition in the ataxia field. We previously demonstrated that Purkinje cells (PCs) in polyglutamine disease spinocerebellar ataxia-1 (SCA1) contain cytoplasmic vacuoles rich in Bergmann glial protein S100B. The vacuolar formation in SCA1 PCs is accompanied with an abnormal morphology of dendritic spines.

Bergmann glial S100B activates myo-inositol monophosphatase 1 and Co-localizes to purkinje cell vacuoles in SCA1 transgenic mice.

Spinocerebellar ataxia-1 (SCA1) is a late onset neurodegenerative disease caused by the expansion of a polyglutamine repeat within ataxin-1 protein. The toxic effects triggered by mutant ataxin-1 result in degeneration of the neurons in cerebellum, brain stem and spinocerebellar tracts. The targeted overexpression of mutant ataxin-1 in cerebellar Purkinje cells (PCs) of the SCA1 transgenic mice results in the formation of cytoplasmic vacuoles in PCs.