Neurodegenerative disease: Two-for-one on potential therapies.

Abstract

Molecules that inhibit the synthesis of the ataxin 2 protein can ameliorate the effects of two neurodegenerative diseases in mouse models, raising hopes for the success of this approach in clinical trials. See Letters p.362 & p.367 Ataxin-2 polyglutamine expansions increase the risk for amyotrophic lateral sclerosis (ALS) and cause spinocerebellar ataxia type 2 (SCA2), two neurodegenerative diseases without a cure. A pair of papers this week report therapeutic approaches towards reducing ataxin 2. Daniel Scoles et al. test antisense oligonucleotides (ASOs) against ataxin-2 in mice models of SCA2 that recreate progressive adult-onset dysfunction and degeneration of the neuronal network. The most promising therapeutic lead is ASO7, which downregulates ATXN2 mRNA and protein and delays the onset of SCA2 phenotypes. Moreover, treatment of symptomatic mice normalizes firing of cerebellar Purkinje cells and improves motor functioning. Nearly all ALS patients have toxic aggregates of the protein TDP-43 in the brain and spinal cord. Lowering ataxin-2 has been shown to suppress TDP-43 toxicity in yeast and flies, and, elsewhere in this issue, Lindsay Becker et al. show that lowering ataxin-2 in mice, genetically or with antisense oligonucleotides, reduces TDP-43 aggregation and toxicity, improves motor function and increases lifespan. Both papers suggest that antisense oligonucleotide-based therapeutic approaches could be used to tackle neurodegeneration. Ataxin-2 polyglutamine expansions increase the risk for amyotrophic lateral sclerosis (ALS) and cause spinocerebellar ataxia type 2 (SCA2), two neurodegenerative diseases without a cure. A pair of papers this week report therapeutic approaches towards reducing ataxin-2. Nearly all ALS patients have toxic aggregates of the protein TDP-43 in the brain and spinal cord. Lowering ataxin-2 has been shown to suppress TDP-43 toxicity in yeast and flies, and Lindsay Becker et al. now show that lowering ataxin-2 in mice, genetically or with antisense oligonucleotides, reduces TDP-43 aggregation and toxicity, improves motor function and increases lifespan. Elsewhere in this issue, Daniel Scoles et al. test antisense oligonucleotides (ASOs) against ataxin-2 in mice models of SCA2 that recreate progressive adult-onset dysfunction and degeneration of the neuronal network. The most promising therapeutic lead is ASO7, which downregulates ATXN2 mRNA and protein and delays the onset of SCA2 phenotypes. Moreover, treatment of symptomatic mice normalizes firing of cerebellar Purkinje cells and improves motor functioning. Both papers suggest that antisense oligonucleotide-based therapeutic approaches could be used to tackle neurodegeneration.