The mutated
ataxin-1 protein in
spinocerebellar ataxia 1 (
SCA1) targets Purkinje cells (PCs) of the cerebellum and causes progressive
ataxia due to loss of PCs and neurons of the brainstem. The exact mechanism of this cellular loss is still not clear. Currently, there are no treatments for
SCA1; however, understanding of the mechanisms that regulate
SCA1 pathology is essential for devising new
therapies for
SCA1 patients. We previously established a connection between the loss of intracellular
calcium-buffering and
calcium-signalling
proteins with initiation of neurodegeneration in
SCA1 transgenic (Tg) mice. Recently,
acid-sensing ion channel 1a (ASIC1a) have been implicated in
calcium-mediated toxicity in many
brain disorders. Here, we report generating
SCA1 Tg mice in the ASIC1a knockout (KO) background and demonstrate that the deletion of ASIC1a gene expression causes suppression of the
SCA1 disease phenotype. Loss of the ASIC1a channel in
SCA1/ASIC1a KO mice resulted in the improvement of motor deficit and decreased PC degeneration. Interestingly, the expression of the ASIC1 variant, ASIC1b, was upregulated in the cerebellum of both
SCA1/ASIC1a KO and ASIC1a KO animals as compared to the wild-type (WT) and
SCA1 Tg mice. Further, these
SCA1/ASIC1a KO mice exhibited translocation of PC
calcium-binding protein calbindin-D28k from the nucleus to the cytosol in young animals, which otherwise have both cytosolic and nuclear localization. Furthermore, in addition to higher expression of
calcium-buffering
protein parvalbumin, PCs of the older
SCA1/ASIC1a KO mice showed a decrease in morphologic abnormalities as compared to the age-matched
SCA1 animals. Our data suggest that ASIC1a may be a mediator of
SCA1 pathogenesis and targeting ASIC1a could be a novel approach to treat
SCA1.