Glial cell activation precedes neurodegeneration in the cerebellar cortex of the YG8–800 murine model of Friedreich ataxia

Friedreich ataxia is a hereditary neurodegenerative disorder resulting from reduced levels of the protein frataxin due to an expanded GAA repeat in the FXN gene. This deficiency causes progressive degeneration of specific neuronal populations in the cerebellum and the consequent loss of movement coo...

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Detalles Bibliográficos
Autores: Vicente-Acosta, Andrés, Herranz-Martín, Saúl, Pazos, Maria Ruth, Galán-Cruz, Jorge, Amores, Mario, Loria, Frida, Díaz-Nido, Javier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/387508
Acceso en línea:http://hdl.handle.net/10261/387508
Access Level:acceso abierto
Palabra clave:Cerebellum
Frataxin
Friedreich ataxia
Glial cells
Neurodegeneration.
Descripción
Sumario:Friedreich ataxia is a hereditary neurodegenerative disorder resulting from reduced levels of the protein frataxin due to an expanded GAA repeat in the FXN gene. This deficiency causes progressive degeneration of specific neuronal populations in the cerebellum and the consequent loss of movement coordination and equilibrium, which are some of the main symptoms observed in affected individuals. Like in other neurodegenerative diseases, previous studies suggest that glial cells could be involved in the neurodegenerative process and disease progression in patients with Friedreich ataxia. In this work, we followed and characterized the progression of changes in the cerebellar cortex in the latest version of Friedreich ataxia humanized mouse model, YG8–800 (Fxn:YG8s(GAA)), which carries a human FXN transgene containing >800 GAA repeats. Comparative analyses of behavioral, histopathological, and biochemical parameters were conducted between the control strain Y47R and YG8–800 mice at different time points. Our findings revealed that YG8–800 mice exhibit an ataxic phenotype characterized by poor motor coordination, decreased body weight, cerebellar atrophy, neuronal loss, and changes in synaptic proteins. Additionally, early activation of glial cells, predominantly astrocytes and microglia, was observed preceding neuronal degeneration, as was increased expression of key proinflammatory cytokines and downregulation of neurotrophic factors. Together, our results show that the YG8–800 mouse model exhibits a stronger phenotype than previous experimental murine models, reliably recapitulating some of the features observed in humans. Accordingly, this humanized model could represent a valuable tool for studying Friedreich ataxia molecular disease mechanisms and for preclinical evaluation of possible therapies.