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Weber JJ, Anger SC, Pereira Sena P, Incebacak Eltemur RD, Huridou C, Fath F, Gross C, Casadei N, Riess O, Nguyen HP. Calpains as novel players in the molecular pathogenesis of spinocerebellar ataxia type 17. Cell Mol Life Sci 2022; 79:262. [PMID: 35482253 PMCID: PMC9050766 DOI: 10.1007/s00018-022-04274-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 03/07/2022] [Accepted: 03/25/2022] [Indexed: 11/23/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is a neurodegenerative disease caused by a polyglutamine-encoding trinucleotide repeat expansion in the gene of transcription factor TATA box-binding protein (TBP). While its underlying pathomechanism is elusive, polyglutamine-expanded TBP fragments of unknown origin mediate the mutant protein’s toxicity. Calcium-dependent calpain proteases are protagonists in neurodegenerative disorders. Here, we demonstrate that calpains cleave TBP, and emerging C-terminal fragments mislocalize to the cytoplasm. SCA17 cell and rat models exhibited calpain overactivation, leading to excessive fragmentation and depletion of neuronal proteins in vivo. Transcriptome analysis of SCA17 cells revealed synaptogenesis and calcium signaling perturbations, indicating the potential cause of elevated calpain activity. Pharmacological or genetic calpain inhibition reduced TBP cleavage and aggregation, consequently improving cell viability. Our work underlines the general significance of calpains and their activating pathways in neurodegenerative disorders and presents these proteases as novel players in the molecular pathogenesis of SCA17.
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Affiliation(s)
- Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Stefanie Cari Anger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Priscila Pereira Sena
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,Graduate School of Cellular Neuroscience, University of Tübingen, 72074, Tübingen, Germany
| | - Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Chrisovalantou Huridou
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Florian Fath
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Caspar Gross
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
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Bonomo R, Latorre A, Bhatia KP. Self-Injurious Behaviour in SCA17: A New Clinical Observation. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2019; 9:tre-09-672. [PMID: 31565537 PMCID: PMC6744813 DOI: 10.7916/tohm.v0.672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 08/06/2019] [Indexed: 12/01/2022]
Abstract
Background Self-injurious behaviour has historically been associated with borderline personality disorder. Nevertheless, over recent years, it has been reported in numerous neurological syndromes, especially hyperkinesias. Case report Two cases of SCA17 manifested self-injurious behaviour, namely repetitive scratching of the skin resulting in severe excoriations. In one of them, the abnormal behaviour was associated with the inability to resist the impulse to commit the act along with relief following the damage. Discussion This is the first report describing self-injurious behaviour in SCA17, but the mechanisms underlying it are still not clear. Further studies are needed to clarify the pathophysiology of such manifestation in hyperkinetic syndromes.
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Affiliation(s)
- Roberta Bonomo
- Department of Clinical and Movement Neurosciences, University College London (UCL) Institute of Neurology, London, UK.,Department "G.F. Ingrassia", Section of Neurosciences, University of Catania, Catania, IT
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, University College London (UCL) Institute of Neurology, London, UK.,Department of Human Neurosciences, Sapienza University of Rome, Rome, IT
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, University College London (UCL) Institute of Neurology, London, UK
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Amato D, Kruyer A, Samaha AN, Heinz A. Hypofunctional Dopamine Uptake and Antipsychotic Treatment-Resistant Schizophrenia. Front Psychiatry 2019; 10:314. [PMID: 31214054 PMCID: PMC6557273 DOI: 10.3389/fpsyt.2019.00314] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/23/2019] [Indexed: 01/07/2023] Open
Abstract
Antipsychotic treatment resistance in schizophrenia remains a major issue in psychiatry. Nearly 30% of patients with schizophrenia do not respond to antipsychotic treatment, yet the underlying neurobiological causes are unknown. All effective antipsychotic medications are thought to achieve their efficacy by targeting the dopaminergic system. Here we review early literature describing the fundamental mechanisms of antipsychotic drug efficacy, highlighting mechanistic concepts that have persisted over time. We then reconsider the original framework for understanding antipsychotic efficacy in light of recent advances in our scientific understanding of the dopaminergic effects of antipsychotics. Based on these new insights, we describe a role for the dopamine transporter in the genesis of both antipsychotic therapeutic response and primary resistance. We believe that this discussion will help delineate the dopaminergic nature of antipsychotic treatment-resistant schizophrenia.
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Affiliation(s)
- Davide Amato
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Andreas Heinz
- Department of Psychiatry, Charité University Medicine Berlin, Campus Charité Mitte, Berlin, Germany
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Synergistic Toxicity of Polyglutamine-Expanded TATA-Binding Protein in Glia and Neuronal Cells: Therapeutic Implications for Spinocerebellar Ataxia 17. J Neurosci 2017; 37:9101-9115. [PMID: 28821675 DOI: 10.1523/jneurosci.0111-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/09/2017] [Accepted: 07/24/2017] [Indexed: 01/12/2023] Open
Abstract
Spinocerebellar ataxia 17 (SCA17) is caused by polyglutamine (polyQ) repeat expansion in the TATA-binding protein (TBP) and is among a family of neurodegenerative diseases in which polyQ expansion leads to preferential neuronal loss in the brain. Although previous studies have demonstrated that expression of polyQ-expanded proteins in glial cells can cause neuronal injury via noncell-autonomous mechanisms, these studies investigated animal models that overexpress transgenic mutant proteins. Since glial cells are particularly reactive to overexpressed mutant proteins, it is important to investigate the in vivo role of glial dysfunction in neurodegeneration when mutant polyQ proteins are endogenously expressed. In the current study, we generated two conditional TBP-105Q knock-in mouse models that specifically express mutant TBP at the endogenous level in neurons or in astrocytes. We found that mutant TBP expression in neuronal cells or astrocytes alone only caused mild neurodegeneration, whereas severe neuronal toxicity requires the expression of mutant TBP in both neuronal and glial cells. Coculture of neurons and astrocytes further validated that mutant TBP in astrocytes promoted neuronal injury. We identified activated inflammatory signaling pathways in mutant TBP-expressing astrocytes, and blocking nuclear factor κB (NF-κB) signaling in astrocytes ameliorated neurodegeneration. Our results indicate that the synergistic toxicity of mutant TBP in neuronal and glial cells plays a critical role in SCA17 pathogenesis and that targeting glial inflammation could be a potential therapeutic approach for SCA17 treatment.SIGNIFICANCE STATEMENT Mutant TBP with polyglutamine expansion preferentially affects neuronal viability in SCA17 patients. Whether glia, the cells that support and protect neurons, contribute to neurodegeneration in SCA17 remains mostly unexplored. In this study, we provide both in vivo and in vitro evidence arguing that endogenous expression of mutant TBP in neurons and glia synergistically impacts neuronal survival. Hyperactivated inflammatory signaling pathways, particularly the NF-κB pathway, underlie glia-mediated neurotoxicity. Moreover, blocking NF-κB activity with small chemical inhibitors alleviated such neurotoxicity. Our study establishes glial dysfunction as an important component of SCA17 pathogenesis and suggests targeting glial inflammation as a potential therapeutic approach for SCA17 treatment.
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