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Sanz-Alcázar A, Britti E, Delaspre F, Medina-Carbonero M, Pazos-Gil M, Tamarit J, Ros J, Cabiscol E. Mitochondrial impairment, decreased sirtuin activity and protein acetylation in dorsal root ganglia in Friedreich Ataxia models. Cell Mol Life Sci 2023; 81:12. [PMID: 38129330 PMCID: PMC10739563 DOI: 10.1007/s00018-023-05064-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 11/16/2023] [Accepted: 11/25/2023] [Indexed: 12/23/2023]
Abstract
Friedreich ataxia (FA) is a rare, recessive neuro-cardiodegenerative disease caused by deficiency of the mitochondrial protein frataxin. Mitochondrial dysfunction, a reduction in the activity of iron-sulfur enzymes, iron accumulation, and increased oxidative stress have been described. Dorsal root ganglion (DRG) sensory neurons are among the cellular types most affected in the early stages of this disease. However, its effect on mitochondrial function remains to be elucidated. In the present study, we found that in primary cultures of DRG neurons as well as in DRGs from the FXNI151F mouse model, frataxin deficiency resulted in lower activity and levels of the electron transport complexes, mainly complexes I and II. In addition, altered mitochondrial morphology, indicative of degeneration was observed in DRGs from FXNI151F mice. Moreover, the NAD+/NADH ratio was reduced and sirtuin activity was impaired. We identified alpha tubulin as the major acetylated protein from DRG homogenates whose levels were increased in FXNI151F mice compared to WT mice. In the mitochondria, superoxide dismutase (SOD2), a SirT3 substrate, displayed increased acetylation in frataxin-deficient DRG neurons. Since SOD2 acetylation inactivates the enzyme, and higher levels of mitochondrial superoxide anion were detected, oxidative stress markers were analyzed. Elevated levels of hydroxynonenal bound to proteins and mitochondrial Fe2+ accumulation was detected when frataxin decreased. Honokiol, a SirT3 activator, restores mitochondrial respiration, decreases SOD2 acetylation and reduces mitochondrial superoxide levels. Altogether, these results provide data at the molecular level of the consequences of electron transport chain dysfunction, which starts negative feedback, contributing to neuron lethality. This is especially important in sensory neurons which have greater susceptibility to frataxin deficiency compared to other tissues.
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Affiliation(s)
- Arabela Sanz-Alcázar
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Elena Britti
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Fabien Delaspre
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Marta Medina-Carbonero
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Maria Pazos-Gil
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Jordi Tamarit
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Joaquim Ros
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain
| | - Elisa Cabiscol
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, IRBLleida, Edifici Biomedicina I, Av. Rovira Roure, 80, 25198, Lleida, Catalonia, Spain.
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Bouchard C, Gérard C, Yanyabé SGF, Majeau N, Aloui M, Buisson G, Yameogo P, Couture V, Tremblay JP. Finding an Appropriate Mouse Model to Study the Impact of a Treatment for Friedreich Ataxia on the Behavioral Phenotype. Genes (Basel) 2023; 14:1654. [PMID: 37628705 PMCID: PMC10454134 DOI: 10.3390/genes14081654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by a GAA repeat in the intron 1 of the frataxin gene (FXN) leading to a lower expression of the frataxin protein. The YG8sR mice are Knock-Out (KO) for their murine frataxin gene but contain a human frataxin transgene derived from an FRDA patient with 300 GAA repeats. These mice are used as a FRDA model but even with a low frataxin concentration, their phenotype is mild. We aimed to find an optimized mouse model with a phenotype comparable to the human patients to study the impact of therapy on the phenotype. We compared two mouse models: the YG8sR injected with an AAV. PHP.B coding for a shRNA targeting the human frataxin gene and the YG8-800, a new mouse model with a human transgene containing 800 GAA repeats. Both mouse models were compared to Y47R mice containing nine GAA repeats that were considered healthy mice. Behavior tests (parallel rod floor apparatus, hanging test, inverted T beam, and notched beam test) were carried out from 2 to 11 months and significant differences were noticed for both YG8sR mice injected with an anti-FXN shRNA and the YG8-800 mice compared to healthy mice. In conclusion, YG8sR mice have a slight phenotype, and injecting them with an AAV-PHP.B expressing an shRNA targeting frataxin does increase their phenotype. The YG8-800 mice have a phenotype comparable to the human ataxic phenotype.
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Affiliation(s)
- Camille Bouchard
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Catherine Gérard
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Solange Gni-fiene Yanyabé
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Nathalie Majeau
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Malek Aloui
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
| | - Gabrielle Buisson
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
| | - Pouiré Yameogo
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Vanessa Couture
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Jacques P. Tremblay
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
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