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Mazere J, Dilharreguy B, Catheline G, Vidailhet M, Deffains M, Vimont D, Ribot B, Barse E, Cif L, Mazoyer B, Langbour N, Pisani A, Allard M, Lamare F, Guehl D, Fernandez P, Burbaud P. Striatal and cerebellar vesicular acetylcholine transporter expression is disrupted in human DYT1 dystonia. Brain 2021; 144:909-923. [PMID: 33638639 DOI: 10.1093/brain/awaa465] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/03/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022] Open
Abstract
Early-onset torsion dystonia (TOR1A/DYT1) is a devastating hereditary motor disorder whose pathophysiology remains unclear. Studies in transgenic mice suggested abnormal cholinergic transmission in the putamen, but this has not yet been demonstrated in humans. The role of the cerebellum in the pathophysiology of the disease has also been highlighted but the involvement of the intrinsic cerebellar cholinergic system is unknown. In this study, cholinergic neurons were imaged using PET with 18F-fluoroethoxybenzovesamicol, a radioligand of the vesicular acetylcholine transporter (VAChT). Here, we found an age-related decrease in VAChT expression in the posterior putamen and caudate nucleus of DYT1 patients versus matched controls, with low expression in young but not in older patients. In the cerebellar vermis, VAChT expression was also significantly decreased in patients versus controls, but independently of age. Functional connectivity within the motor network studied in MRI and the interregional correlation of VAChT expression studied in PET were also altered in patients. These results show that the cholinergic system is disrupted in the brain of DYT1 patients and is modulated over time through plasticity or compensatory mechanisms.
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Affiliation(s)
- Joachim Mazere
- Department of Nuclear Medicine, CHU de Bordeaux, France.,Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Bixente Dilharreguy
- Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Gwenaëlle Catheline
- Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Marie Vidailhet
- Institut du Cerveau et de la Moelle épinière (ICM) UMR 1127, hôpital de la Pitié-Salpétrière, Department of Neurology, AP-HP, Sorbonne Université, 75013, Paris, France
| | - Marc Deffains
- Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France
| | - Delphine Vimont
- Department of Nuclear Medicine, CHU de Bordeaux, France.,Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Bastien Ribot
- Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France
| | - Elodie Barse
- Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Laura Cif
- Department of Neurosurgery, CHU de Montpellier, 34000, France
| | - Bernard Mazoyer
- Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France
| | - Nicolas Langbour
- Centre de Recherche en Psychiatrie, CH de la Milétrie, 86000, Poitiers, France
| | - Antonio Pisani
- Department of Brain and Behavioural Sciences, University of Pavia, Italy.,IRCCS Mondino Foundation, Pavia, Italy
| | - Michèle Allard
- Department of Nuclear Medicine, CHU de Bordeaux, France.,Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Frédéric Lamare
- Department of Nuclear Medicine, CHU de Bordeaux, France.,Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Dominique Guehl
- Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France.,Service de Neurophysiologie Clinique, Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
| | - Philippe Fernandez
- Department of Nuclear Medicine, CHU de Bordeaux, France.,Institute of Cognitive and Integrative Neurosciences, CNRS UMR 5287, Bordeaux University, F33000, Bordeaux, France
| | - Pierre Burbaud
- Institut des Maladies Neurodégénératives (IMN, CNRS U5393), Université de Bordeaux, 33076, Bordeaux, France.,Service de Neurophysiologie Clinique, Pôle des Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
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DYT-TOR1A subcellular proteomics reveals selective vulnerability of the nuclear proteome to cell stress. Neurobiol Dis 2021; 158:105464. [PMID: 34358617 DOI: 10.1016/j.nbd.2021.105464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 07/07/2021] [Accepted: 08/02/2021] [Indexed: 11/23/2022] Open
Abstract
TorsinA is a AAA+ ATPase that shuttles between the ER lumen and outer nuclear envelope in an ATP-dependent manner and is functionally implicated in nucleocytoplasmic transport. We hypothesized that the DYT-TOR1A dystonia disease-causing variant, ΔE TorsinA, may therefore disrupt the normal subcellular distribution of proteins between the nuclear and cytosolic compartments. To test this hypothesis, we performed proteomic analysis on nuclear and cytosolic subcellular fractions from DYT-TOR1A and wildtype mouse embryonic fibroblasts (MEFs). We further examined the compartmental proteomes following exposure to thapsigargin (Tg), an endoplasmic reticulum (ER) stressor, because DYT-TOR1A dystonia models have previously shown abnormalities in cellular stress responses. Across both subcellular compartments, proteomes of DYT-TOR1A cells showed basal state disruptions consistent with an activated stress response, and in response to thapsigargin, a blunted stress response. However, the DYT-TOR1A nuclear proteome under Tg cell stress showed the most pronounced and disproportionate degree of protein disruptions - 3-fold greater than all other conditions. The affected proteins extended beyond those typically associated with stress responses, including enrichments for processes critical for neuronal synaptic function. These findings highlight the advantage of subcellular proteomics to reveal events that localize to discrete subcellular compartments and refine thinking about the mechanisms and significance of cell stress in DYT-TOR1A pathogenesis.
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Mutant Allele-Specific CRISPR Disruption in DYT1 Dystonia Fibroblasts Restores Cell Function. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 21:1-12. [PMID: 32502938 PMCID: PMC7270506 DOI: 10.1016/j.omtn.2020.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/15/2020] [Accepted: 05/12/2020] [Indexed: 12/16/2022]
Abstract
Most individuals affected with DYT1 dystonia have a heterozygous 3-bp deletion in the TOR1A gene (c.907_909delGAG). The mutation appears to act through a dominant-negative mechanism compromising normal torsinA function, and it is proposed that reducing mutant torsinA may normalize torsinA activity. In this study, we used an engineered Cas9 variant from Streptococcus pyogenes (SpCas9-VRQR) to target the mutation in the TOR1A gene in order to disrupt mutant torsinA in DYT1 patient fibroblasts. Selective targeting of the DYT1 allele was highly efficient with most common non-homologous end joining (NHEJ) edits, leading to a predicted premature stop codon with loss of the torsinA C terminus (delta 302–332 aa). Structural analysis predicted a functionally inactive status of this truncated torsinA due to the loss of residues associated with ATPase activity and binding to LULL1. Immunoblotting showed a reduction of the torsinA protein level in Cas9-edited DYT1 fibroblasts, and a functional assay using HSV infection indicated a phenotypic recovery toward that observed in control fibroblasts. These findings suggest that the selective disruption of the mutant TOR1A allele using CRISPR-Cas9 inactivates mutant torsinA, allowing the remaining wild-type torsinA to exert normal function.
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