Related Experiment Video
Updated: Aug 25, 2025
A Simple Composite Phenotype Scoring System for Evaluating Mouse Models of Cerebellar Ataxia
Published on: May 21, 2010
Mutant Ataxin-2 Expression in Aged Animals Aggravates Neuropathological Features Associated with Spinocerebellar
Inês T Afonso1,2,3, Patrícia Lima1,2, André Conceição1,2,3,4
1Algarve Biomedical Center-Research Institute, 8005-139 Faro, Portugal.
Abstract:
Spinocerebellar ataxia type 2 (SCA2) is a rare autosomal, dominantly inherited disease, in which the affected individuals have a disease onset around their third life decade. The molecular mechanisms underlying SCA2 are not yet completely understood, for which we hypothesize that aging plays a role in SCA2 molecular pathogenesis. In this study, we performed a striatal injection of mutant ataxin-2 mediated by lentiviral vectors, in young and aged animals. Twelve weeks post-injection, we analyzed the striatum for SCA2 neuropathological features and specific aging hallmarks. Our results show that aged animals had a higher number of mutant ataxin-2 aggregates and more neuronal marker loss, compared to young animals. Apoptosis markers, cleaved caspase-3, and cresyl violet staining also indicated increased neuronal death in the aged animal group. Additionally, mRNA levels of microtubule-associated protein 1 light-chain 3B (LC3) and sequestosome-1 (SQSTM1/p62) were altered in the aged animal group, suggesting autophagic pathway dysfunction. This work provides evidence that aged animals injected with expanded ataxin-2 had aggravated SCA2 disease phenotype, suggesting that aging plays an important role in SCA2 disease onset and disease progression.
Insights
Aging exacerbates spinocerebellar ataxia type 2 (SCA2) by increasing mutant ataxin-2 aggregates and neuronal death. This study suggests aging significantly impacts SCA2 pathogenesis and progression.
Area of Science:
- Neuroscience
- Genetics
- Aging Research
Background:
- Spinocerebellar ataxia type 2 (SCA2) is a rare, autosomal dominant neurodegenerative disorder.
- The precise molecular mechanisms of SCA2 pathogenesis remain unclear, prompting investigation into the role of aging.
Purpose of the Study:
- To investigate the influence of aging on the molecular pathogenesis and neuropathological features of spinocerebellar ataxia type 2 (SCA2).
Main Methods:
- Striatal injection of mutant ataxin-2 using lentiviral vectors in young and aged animal models.
- Analysis of SCA2 neuropathological markers and aging hallmarks 12 weeks post-injection.
- Assessment of apoptosis and autophagic pathway markers (LC3, SQSTM1/p62).
Main Results:
- Aged animals exhibited significantly higher numbers of mutant ataxin-2 aggregates and greater neuronal marker loss compared to young animals.
- Increased neuronal death was observed in aged animals, indicated by apoptosis markers and staining.
- Altered mRNA levels of LC3 and SQSTM1/p62 in aged animals suggest impaired autophagic pathway function.
Conclusions:
- Aging significantly aggravates the SCA2 disease phenotype, characterized by increased protein aggregation and neurodegeneration.
- The findings provide evidence that aging is a critical factor in the onset and progression of SCA2.
- Autophagic pathway dysfunction may contribute to the exacerbated SCA2 phenotype in aged individuals.
