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Pan K, Jinnah HA, Hess EJ, Smith Y, Villalba RM. Ultrastructural analysis of nigrostriatal dopaminergic terminals in a knockin mouse model of DYT1 dystonia. Eur J Neurosci 2024; 59:1407-1427. [PMID: 38123503 DOI: 10.1111/ejn.16197] [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: 03/08/2023] [Revised: 11/02/2023] [Accepted: 11/05/2023] [Indexed: 12/23/2023]
Abstract
DYT1 dystonia is associated with decreased striatal dopamine release. In this study, we examined the possibility that ultrastructural changes of nigrostriatal dopamine terminals could contribute to this neurochemical imbalance using a serial block face/scanning electron microscope (SBF/SEM) and three-dimensional reconstruction to analyse striatal tyrosine hydroxylase-immunoreactive (TH-IR) terminals and their synapses in a DYT1(ΔE) knockin (DYT1-KI) mouse model of DYT1 dystonia. Furthermore, to study possible changes in vesicle packaging capacity of dopamine, we used transmission electron microscopy to assess the synaptic vesicle size in striatal dopamine terminals. Quantitative comparative analysis of 80 fully reconstructed TH-IR terminals in the WT and DYT1-KI mice indicate (1) no significant difference in the volume of TH-IR terminals; (2) no major change in the proportion of axo-spinous versus axo-dendritic synapses; (3) no significant change in the post-synaptic density (PSD) area of axo-dendritic synapses, while the PSDs of axo-spinous synapses were significantly smaller in DYT1-KI mice; (4) no significant change in the contact area between TH-IR terminals and dendritic shafts or spines, while the ratio of PSD area/contact area decreased significantly for both axo-dendritic and axo-spinous synapses in DYT1-KI mice; (5) no significant difference in the mitochondria volume; and (6) no significant difference in the synaptic vesicle area between the two groups. Altogether, these findings suggest that abnormal morphometric changes of nigrostriatal dopamine terminals and their post-synaptic targets are unlikely to be a major source of reduced striatal dopamine release in DYT1 dystonia.
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Affiliation(s)
- Ke Pan
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Physical Therapy & Human Movement Sciences, Northwestern University, Chicago, Illinois, USA
| | - Hyder A Jinnah
- Department of Neurology, Emory University, Atlanta, Georgia, USA
- Department of Human Genetics and Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Ellen J Hess
- Department of Neurology, Emory University, Atlanta, Georgia, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
| | - Yoland Smith
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Neurology, Emory University, Atlanta, Georgia, USA
| | - Rosa M Villalba
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
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2
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Fan Y, Si Z, Wang L, Zhang L. DYT- TOR1A dystonia: an update on pathogenesis and treatment. Front Neurosci 2023; 17:1216929. [PMID: 37638318 PMCID: PMC10448058 DOI: 10.3389/fnins.2023.1216929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
DYT-TOR1A dystonia is a neurological disorder characterized by involuntary muscle contractions and abnormal movements. It is a severe genetic form of dystonia caused by mutations in the TOR1A gene. TorsinA is a member of the AAA + family of adenosine triphosphatases (ATPases) involved in a variety of cellular functions, including protein folding, lipid metabolism, cytoskeletal organization, and nucleocytoskeletal coupling. Almost all patients with TOR1A-related dystonia harbor the same mutation, an in-frame GAG deletion (ΔGAG) in the last of its 5 exons. This recurrent variant results in the deletion of one of two tandem glutamic acid residues (i.e., E302/303) in a protein named torsinA [torsinA(△E)]. Although the mutation is hereditary, not all carriers will develop DYT-TOR1A dystonia, indicating the involvement of other factors in the disease process. The current understanding of the pathophysiology of DYT-TOR1A dystonia involves multiple factors, including abnormal protein folding, signaling between neurons and glial cells, and dysfunction of the protein quality control system. As there are currently no curative treatments for DYT-TOR1A dystonia, progress in research provides insight into its pathogenesis, leading to potential therapeutic and preventative strategies. This review summarizes the latest research advances in the pathogenesis, diagnosis, and treatment of DYT-TOR1A dystonia.
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Affiliation(s)
- Yuhang Fan
- Department of Neurology, the Second Hospital of Jilin University, Changchun, China
| | - Zhibo Si
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, China
| | - Linlin Wang
- Department of Ultrasound, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Lei Zhang
- Department of Neurology, the Second Hospital of Jilin University, Changchun, China
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3
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Ponterio G, Faustini G, El Atiallah I, Sciamanna G, Meringolo M, Tassone A, Imbriani P, Cerri S, Martella G, Bonsi P, Bellucci A, Pisani A. Alpha-Synuclein is Involved in DYT1 Dystonia Striatal Synaptic Dysfunction. Mov Disord 2022; 37:949-961. [PMID: 35420219 PMCID: PMC9323501 DOI: 10.1002/mds.29024] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/24/2022] [Accepted: 03/19/2022] [Indexed: 12/26/2022] Open
Abstract
Background The neuronal protein alpha‐synuclein (α‐Syn) is crucially involved in Parkinson's disease pathophysiology. Intriguingly, torsinA (TA), the protein causative of DYT1 dystonia, has been found to accumulate in Lewy bodies and to interact with α‐Syn. Both proteins act as molecular chaperones and control synaptic machinery. Despite such evidence, the role of α‐Syn in dystonia has never been investigated. Objective We explored whether α‐Syn and N‐ethylmaleimide sensitive fusion attachment protein receptor proteins (SNAREs), that are known to be modulated by α‐Syn, may be involved in DYT1 dystonia synaptic dysfunction. Methods We used electrophysiological and biochemical techniques to study synaptic alterations in the dorsal striatum of the Tor1a+/Δgag mouse model of DYT1 dystonia. Results In the Tor1a+/Δgag DYT1 mutant mice, we found a significant reduction of α‐Syn levels in whole striata, mainly involving glutamatergic corticostriatal terminals. Strikingly, the striatal levels of the vesicular SNARE VAMP‐2, a direct α‐Syn interactor, and of the transmembrane SNARE synaptosome‐associated protein 23 (SNAP‐23), that promotes glutamate synaptic vesicles release, were markedly decreased in mutant mice. Moreover, we detected an impairment of miniature glutamatergic postsynaptic currents (mEPSCs) recorded from striatal spiny neurons, in parallel with a decreased asynchronous release obtained by measuring quantal EPSCs (qEPSCs), which highlight a robust alteration in release probability. Finally, we also observed a significant reduction of TA striatal expression in α‐Syn null mice. Conclusions Our data demonstrate an unprecedented relationship between TA and α‐Syn, and reveal that α‐Syn and SNAREs alterations characterize the synaptic dysfunction underlying DYT1 dystonia. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.
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Affiliation(s)
- Giulia Ponterio
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Ilham El Atiallah
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giuseppe Sciamanna
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,UniCamillus-Saint Camillus International University of Health Sciences, Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Annalisa Tassone
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Paola Imbriani
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | | | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Antonio Pisani
- IRCCS Fondazione Mondino, Pavia, Italy.,Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
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Tassone A, Martella G, Meringolo M, Vanni V, Sciamanna G, Ponterio G, Imbriani P, Bonsi P, Pisani A. Vesicular Acetylcholine Transporter Alters Cholinergic Tone and Synaptic Plasticity in DYT1 Dystonia. Mov Disord 2021; 36:2768-2779. [PMID: 34173686 PMCID: PMC9291835 DOI: 10.1002/mds.28698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/18/2021] [Accepted: 06/07/2021] [Indexed: 11/17/2022] Open
Abstract
Background Acetylcholine‐mediated transmission plays a central role in the impairment of corticostriatal synaptic activity and plasticity in multiple DYT1 mouse models. However, the nature of such alteration remains unclear. Objective The aim of the present work was to characterize the mechanistic basis of cholinergic dysfunction in DYT1 dystonia to identify potential targets for pharmacological intervention. Methods We utilized electrophysiology recordings, immunohistochemistry, enzymatic activity assays, and Western blotting techniques to analyze in detail the cholinergic machinery in the dorsal striatum of the Tor1a+/− mouse model of DYT1 dystonia. Results We found a significant increase in the vesicular acetylcholine transporter (VAChT) protein level, the protein responsible for loading acetylcholine (ACh) from the cytosol into synaptic vesicles, which indicates an altered cholinergic tone. Accordingly, in Tor1a+/− mice we measured a robust elevation in basal ACh content coupled to a compensatory enhancement of acetylcholinesterase (AChE) enzymatic activity. Moreover, pharmacological activation of dopamine D2 receptors, which is expected to reduce ACh levels, caused an abnormal elevation in its content, as compared to controls. Patch‐clamp recordings revealed a reduced effect of AChE inhibitors on cholinergic interneuron excitability, whereas muscarinic autoreceptor function was preserved. Finally, we tested the hypothesis that blockade of VAChT could restore corticostriatal long‐term synaptic plasticity deficits. Vesamicol, a selective VAChT inhibitor, rescued a normal expression of synaptic plasticity. Conclusions Overall, our findings indicate that VAChT is a key player in the alterations of striatal plasticity and a novel target to normalize cholinergic dysfunction observed in DYT1 dystonia. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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Affiliation(s)
- Annalisa Tassone
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Valentina Vanni
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Giuseppe Sciamanna
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Giulia Ponterio
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Paola Imbriani
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Antonio Pisani
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation, Pavia, Italy
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5
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Xu L, Yang Z, Li W, Luo Z, Zhang C, Huang X, Ma S, Long Y, Chu Y, Qian Y, Wang X, Sun H. Cellular analysis of a novel mutation p. Ser287Tyr in TOR1A in late-onset isolated dystonia. Neurobiol Dis 2020; 140:104851. [PMID: 32243914 DOI: 10.1016/j.nbd.2020.104851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/06/2020] [Accepted: 03/29/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Variations in TOR1A were thought to be associated with early-onset isolated dystonia. The variant S287Y (NM_000113.2: c.860C > A, p. Ser287Tyr, rs766483672) was found in our late-onset isolated dystonia patient. This missense variant is adjacent to R288Q (c.863G > A, p. Arg288Gln), which was reported to be associated with isolated dystonia. The potentially pathogenic role of S287Y is not conclusively known. METHODS Cytological and molecular biological analyses were performed in vitro to determine whether this variant damages the structure and function of the cell. RESULTS Compared with the SH-SY5Y cells overexpressing wild-type TOR1A, the cells overexpressing the protein with S287Y have an enlarged peri-nuclear space. The same changes in nuclear morphology were also found in the cells overexpressing the pathogenic variants ΔE (NM_000113.2:c.904_906delGAG, p. Glu302del), F205I (NM_000113.2:c.613 T > A, p. Phe205Ile), and R288Q (NM_000113.2:c.863G > A, p. Arg288Gln). Mutated proteins with S287Y presented a higher tendency to form dimers under reducing conditions. The same tendencies were observed in other mutated proteins but not in wild-type torsinA. CONCLUSIONS TorsinA with S287Y damages the structure of the cell nucleus and may be a novel pathogenic mutation that causes isolated dystonia.
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Affiliation(s)
- Longjiang Xu
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Zhaoqing Yang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Wenwu Li
- The Department of Neurology, The People's Hospital of ChuXiong Yi Autonomous Prefecture, Chuxiong, China
| | - Zhiling Luo
- The Department of Ultrasound, Yunnan Fuwai Cardiovascular Hospital, Kunming, China
| | - Changjun Zhang
- Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Shiyan, China
| | - Xiaoqin Huang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Shaohui Ma
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Yuzhou Long
- The Second People's Hospital of Yunnan Province, Kunming, China
| | - Yan Chu
- The Second People's Hospital of Yunnan Province, Kunming, China
| | - Yuan Qian
- Yunnan Key Laboratory of Laboratory Medicine, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiuyun Wang
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Hao Sun
- The Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China.
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6
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Unraveling Molecular Mechanisms of THAP1 Missense Mutations in DYT6 Dystonia. J Mol Neurosci 2020; 70:999-1008. [PMID: 32112337 PMCID: PMC7334247 DOI: 10.1007/s12031-020-01490-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Mutations in THAP1 (THAP domain-containing apoptosis-associated protein 1) are responsible for DYT6 dystonia. Until now, more than eighty different mutations in THAP1 gene have been found in patients with primary dystonia, and two third of them are missense mutations. The potential pathogeneses of these missense mutations in human are largely elusive. In the present study, we generated stable transfected human neuronal cell lines expressing wild-type or mutated THAP1 proteins found in DYT6 patients. Transcriptional profiling using microarrays revealed a set of 28 common genes dysregulated in two mutated THAP1 (S21T and F81L) overexpression cell lines suggesting a common mechanism of these mutations. ChIP-seq showed that THAP1 can bind to the promoter of one of these genes, superoxide dismutase 2 (SOD2). Overexpression of THAP1 in SK-N-AS cells resulted in increased SOD2 protein expression, whereas fibroblasts from THAP1 patients have less SOD2 expression, which indicates that SOD2 is a direct target gene of THAP1. In addition, we show that some THAP1 mutations (C54Y and F81L) decrease the protein stability which might also be responsible for altered transcription regulation due to dosage insufficiency. Taking together, the current study showed different potential pathogenic mechanisms of THAP1 mutations which lead to the same consequence of DYT6 dystonia.
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7
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Bonsi P, Ponterio G, Vanni V, Tassone A, Sciamanna G, Migliarini S, Martella G, Meringolo M, Dehay B, Doudnikoff E, Zachariou V, Goodchild RE, Mercuri NB, D'Amelio M, Pasqualetti M, Bezard E, Pisani A. RGS9-2 rescues dopamine D2 receptor levels and signaling in DYT1 dystonia mouse models. EMBO Mol Med 2019; 11:emmm.201809283. [PMID: 30552094 PMCID: PMC6328939 DOI: 10.15252/emmm.201809283] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Dopamine D2 receptor signaling is central for striatal function and movement, while abnormal activity is associated with neurological disorders including the severe early-onset DYT1 dystonia. Nevertheless, the mechanisms that regulate D2 receptor signaling in health and disease remain poorly understood. Here, we identify a reduced D2 receptor binding, paralleled by an abrupt reduction in receptor protein level, in the striatum of juvenile Dyt1 mice. This occurs through increased lysosomal degradation, controlled by competition between β-arrestin 2 and D2 receptor binding proteins. Accordingly, we found lower levels of striatal RGS9-2 and spinophilin. Further, we show that genetic depletion of RGS9-2 mimics the D2 receptor loss of DYT1 dystonia striatum, whereas RGS9-2 overexpression rescues both receptor levels and electrophysiological responses in Dyt1 striatal neurons. This work uncovers the molecular mechanism underlying D2 receptor downregulation in Dyt1 mice and in turn explains why dopaminergic drugs lack efficacy in DYT1 patients despite significant evidence for striatal D2 receptor dysfunction. Our data also open up novel avenues for disease-modifying therapeutics to this incurable neurological disorder.
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Affiliation(s)
- Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Giulia Ponterio
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Valentina Vanni
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Annalisa Tassone
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Giuseppe Sciamanna
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Sara Migliarini
- Unit of Cell and Developmental Biology, Department of Biology, University of Pisa, Pisa, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Benjamin Dehay
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Evelyne Doudnikoff
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Venetia Zachariou
- Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rose E Goodchild
- Department of Neurosciences, VIB-KU Leuven Center for Brain and Disease Research, KU Leuven, Leuven, Belgium
| | - Nicola B Mercuri
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systems Medicine, University Tor Vergata, Rome, Italy
| | - Marcello D'Amelio
- Laboratory Molecular Neurosciences, IRCCS Fondazione Santa Lucia, Rome, Italy.,Unit of Molecular Neurosciences, Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Massimo Pasqualetti
- Unit of Cell and Developmental Biology, Department of Biology, University of Pisa, Pisa, Italy.,Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy
| | - Erwan Bezard
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Antonio Pisani
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Rome, Italy .,Department of Systems Medicine, University Tor Vergata, Rome, Italy
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8
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Gonzalez-Alegre P. Advances in molecular and cell biology of dystonia: Focus on torsinA. Neurobiol Dis 2019; 127:233-241. [DOI: 10.1016/j.nbd.2019.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/20/2019] [Accepted: 03/09/2019] [Indexed: 12/15/2022] Open
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9
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Structural and Functional Characterization of the Interaction of Snapin with the Dopamine Transporter: Differential Modulation of Psychostimulant Actions. Neuropsychopharmacology 2018; 43:1041-1051. [PMID: 28905875 PMCID: PMC5854797 DOI: 10.1038/npp.2017.217] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 12/12/2022]
Abstract
The importance of dopamine (DA) neurotransmission is emphasized by its direct implication in several neurological and psychiatric disorders. The DA transporter (DAT), target of psychostimulant drugs, is the key protein that regulates spatial and temporal activity of DA in the synaptic cleft via the rapid reuptake of DA into the presynaptic terminal. There is strong evidence suggesting that DAT-interacting proteins may have a role in its function and regulation. Performing a two-hybrid screening, we identified snapin, a SNARE-associated protein implicated in synaptic transmission, as a new binding partner of the carboxyl terminal of DAT. Our data show that snapin is a direct partner and regulator of DAT. First, we determined the domains required for this interaction in both proteins and characterized the DAT-snapin interface by generating a 3D model. Using different approaches, we demonstrated that (i) snapin is expressed in vivo in dopaminergic neurons along with DAT; (ii) both proteins colocalize in cultured cells and brain and, (iii) DAT and snapin are present in the same protein complex. Moreover, by functional studies we showed that snapin produces a significant decrease in DAT uptake activity. Finally, snapin downregulation in mice produces an increase in DAT levels and transport activity, hence increasing DA concentration and locomotor response to amphetamine. In conclusion, snapin/DAT interaction represents a direct link between exocytotic and reuptake mechanisms and is a potential target for DA transmission modulation.
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10
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Zhang J, Weinrich JAP, Russ JB, Comer JD, Bommareddy PK, DiCasoli RJ, Wright CVE, Li Y, van Roessel PJ, Kaltschmidt JA. A Role for Dystonia-Associated Genes in Spinal GABAergic Interneuron Circuitry. Cell Rep 2017; 21:666-678. [PMID: 29045835 PMCID: PMC5658202 DOI: 10.1016/j.celrep.2017.09.079] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 09/08/2017] [Accepted: 09/24/2017] [Indexed: 12/17/2022] Open
Abstract
Spinal interneurons are critical modulators of motor circuit function. In the dorsal spinal cord, a set of interneurons called GABApre presynaptically inhibits proprioceptive sensory afferent terminals, thus negatively regulating sensory-motor signaling. Although deficits in presynaptic inhibition have been inferred in human motor diseases, including dystonia, it remains unclear whether GABApre circuit components are altered in these conditions. Here, we use developmental timing to show that GABApre neurons are a late Ptf1a-expressing subclass and localize to the intermediate spinal cord. Using a microarray screen to identify genes expressed in this intermediate population, we find the kelch-like family member Klhl14, implicated in dystonia through its direct binding with torsion-dystonia-related protein Tor1a. Furthermore, in Tor1a mutant mice in which Klhl14 and Tor1a binding is disrupted, formation of GABApre sensory afferent synapses is impaired. Our findings suggest a potential contribution of GABApre neurons to the deficits in presynaptic inhibition observed in dystonia.
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Affiliation(s)
- Juliet Zhang
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA; Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA
| | - Jarret A P Weinrich
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA; Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA
| | - Jeffrey B Russ
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA; Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - John D Comer
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA; Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Praveen K Bommareddy
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
| | - Richard J DiCasoli
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
| | - Christopher V E Wright
- Vanderbilt University Program in Developmental Biology, Vanderbilt Center for Stem Cell Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Yuqing Li
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Peter J van Roessel
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Julia A Kaltschmidt
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA; Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA; Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065, USA; Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
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11
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Rittiner JE, Caffall ZF, Hernández-Martinez R, Sanderson SM, Pearson JL, Tsukayama KK, Liu AY, Xiao C, Tracy S, Shipman MK, Hickey P, Johnson J, Scott B, Stacy M, Saunders-Pullman R, Bressman S, Simonyan K, Sharma N, Ozelius LJ, Cirulli ET, Calakos N. Functional Genomic Analyses of Mendelian and Sporadic Disease Identify Impaired eIF2α Signaling as a Generalizable Mechanism for Dystonia. Neuron 2016; 92:1238-1251. [PMID: 27939583 DOI: 10.1016/j.neuron.2016.11.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/27/2016] [Accepted: 11/04/2016] [Indexed: 01/09/2023]
Abstract
Dystonia is a brain disorder causing involuntary, often painful movements. Apart from a role for dopamine deficiency in some forms, the cellular mechanisms underlying most dystonias are currently unknown. Here, we discover a role for deficient eIF2α signaling in DYT1 dystonia, a rare inherited generalized form, through a genome-wide RNAi screen. Subsequent experiments including patient-derived cells and a mouse model support both a pathogenic role and therapeutic potential for eIF2α pathway perturbations. We further find genetic and functional evidence supporting similar pathway impairment in patients with sporadic cervical dystonia, due to rare coding variation in the eIF2α effector ATF4. Considering also that another dystonia, DYT16, involves a gene upstream of the eIF2α pathway, these results mechanistically link multiple forms of dystonia and put forth a new overall cellular mechanism for dystonia pathogenesis, impairment of eIF2α signaling, a pathway known for its roles in cellular stress responses and synaptic plasticity.
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Affiliation(s)
| | | | | | | | - James L Pearson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Department of RNAi Screening Facility, Duke University, Durham, NC 27708, USA
| | | | - Anna Y Liu
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Changrui Xiao
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Samantha Tracy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | | | - Patrick Hickey
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Julia Johnson
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Burton Scott
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Mark Stacy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Rachel Saunders-Pullman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Susan Bressman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kristina Simonyan
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth T Cirulli
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Nicole Calakos
- Department of Neurology, Duke University, Durham, NC 27708, USA; Department of Neurobiology, Duke University, Durham, NC 27708, USA.
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Kolobynina KG, Solovyova VV, Levay K, Rizvanov AA, Slepak VZ. Emerging roles of the single EF-hand Ca2+ sensor tescalcin in the regulation of gene expression, cell growth and differentiation. J Cell Sci 2016; 129:3533-3540. [PMID: 27609838 DOI: 10.1242/jcs.191486] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Tescalcin (TESC, also known as calcineurin-homologous protein 3, CHP3) is a 24-kDa EF-hand Ca2+-binding protein that has recently emerged as a regulator of cell differentiation and growth. The TESC gene has also been linked to human brain abnormalities, and high expression of tescalcin has been found in several cancers. The expression level of tescalcin changes dramatically during development and upon signal-induced cell differentiation. Recent studies have shown that tescalcin is not only subjected to up- or down-regulation, but also has an active role in pathways that drive cell growth and differentiation programs. At the molecular level, there is compelling experimental evidence showing that tescalcin can directly interact with and regulate the activities of the Na+/H+ exchanger NHE1, subunit 4 of the COP9 signalosome (CSN4) and protein kinase glycogen-synthase kinase 3 (GSK3). In hematopoetic precursor cells, tescalcin has been shown to couple activation of the extracellular signal-regulated kinase (ERK) cascade to the expression of transcription factors that control cell differentiation. The purpose of this Commentary is to summarize recent efforts that have served to characterize the biochemical, genetic and physiological attributes of tescalcin, and its unique role in the regulation of various cellular functions.
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Affiliation(s)
- Ksenia G Kolobynina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Valeria V Solovyova
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Konstantin Levay
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Albert A Rizvanov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Vladlen Z Slepak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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13
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Demircioglu FE, Sosa BA, Ingram J, Ploegh HL, Schwartz TU. Structures of TorsinA and its disease-mutant complexed with an activator reveal the molecular basis for primary dystonia. eLife 2016; 5:e17983. [PMID: 27490483 PMCID: PMC4999309 DOI: 10.7554/elife.17983] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/03/2016] [Indexed: 01/07/2023] Open
Abstract
The most common cause of early onset primary dystonia, a neuromuscular disease, is a glutamate deletion (ΔE) at position 302/303 of TorsinA, a AAA+ ATPase that resides in the endoplasmic reticulum. While the function of TorsinA remains elusive, the ΔE mutation is known to diminish binding of two TorsinA ATPase activators: lamina-associated protein 1 (LAP1) and its paralog, luminal domain like LAP1 (LULL1). Using a nanobody as a crystallization chaperone, we obtained a 1.4 Å crystal structure of human TorsinA in complex with LULL1. This nanobody likewise stabilized the weakened TorsinAΔE-LULL1 interaction, which enabled us to solve its structure at 1.4 Å also. A comparison of these structures shows, in atomic detail, the subtle differences in activator interactions that separate the healthy from the diseased state. This information may provide a structural platform for drug development, as a small molecule that rescues TorsinAΔE could serve as a cure for primary dystonia.
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Affiliation(s)
- F Esra Demircioglu
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Brian A Sosa
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Jessica Ingram
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Hidde L Ploegh
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Thomas U Schwartz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States,
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14
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Abstract
Torsin ATPases (Torsins) belong to the widespread AAA+ (ATPases associated with a variety of cellular activities) family of ATPases, which share structural similarity but have diverse cellular functions. Torsins are outliers in this family because they lack many characteristics of typical AAA+ proteins, and they are the only members of the AAA+ family located in the endoplasmic reticulum and contiguous perinuclear space. While it is clear that Torsins have essential roles in many, if not all metazoans, their precise cellular functions remain elusive. Studying Torsins has significant medical relevance since mutations in Torsins or Torsin-associated proteins result in a variety of congenital human disorders, the most frequent of which is early-onset torsion (DYT1) dystonia, a severe movement disorder. A better understanding of the Torsin system is needed to define the molecular etiology of these diseases, potentially enabling corrective therapy. Here, we provide a comprehensive overview of the Torsin system in metazoans, discuss functional clues obtained from various model systems and organisms and provide a phylogenetic and structural analysis of Torsins and their regulatory cofactors in relation to disease-causative mutations. Moreover, we review recent data that have led to a dramatically improved understanding of these machines at a molecular level, providing a foundation for investigating the molecular defects underlying the associated movement disorders. Lastly, we discuss our ideas on how recent progress may be utilized to inform future studies aimed at determining the cellular role(s) of these atypical molecular machines and their implications for dystonia treatment options.
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Affiliation(s)
- April E Rose
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Rebecca S H Brown
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Christian Schlieker
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and.,b Department of Cell Biology , Yale School of Medicine , New Haven , CT , USA
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15
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Cerebellar synaptogenesis is compromised in mouse models of DYT1 dystonia. Exp Neurol 2015; 271:457-67. [DOI: 10.1016/j.expneurol.2015.07.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/01/2015] [Accepted: 07/07/2015] [Indexed: 12/16/2022]
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Yokoi F, Chen HX, Dang MT, Cheetham CC, Campbell SL, Roper SN, Sweatt JD, Li Y. Behavioral and electrophysiological characterization of Dyt1 heterozygous knockout mice. PLoS One 2015; 10:e0120916. [PMID: 25799505 PMCID: PMC4370625 DOI: 10.1371/journal.pone.0120916] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 01/28/2015] [Indexed: 12/19/2022] Open
Abstract
DYT1 dystonia is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most of the patients have a trinucleotide deletion (ΔGAG) corresponding to a glutamic acid in the C-terminal region (torsinA(ΔE)). Dyt1 ΔGAG heterozygous knock-in (KI) mice, which mimic ΔGAG mutation in the endogenous gene, exhibit motor deficits and deceased frequency of spontaneous excitatory post-synaptic currents (sEPSCs) and normal theta-burst-induced long-term potentiation (LTP) in the hippocampal CA1 region. Although Dyt1 KI mice show decreased hippocampal torsinA levels, it is not clear whether the decreased torsinA level itself affects the synaptic plasticity or torsinA(ΔE) does it. To analyze the effect of partial torsinA loss on motor behaviors and synaptic transmission, Dyt1 heterozygous knock-out (KO) mice were examined as a model of a frame-shift DYT1 mutation in patients. Consistent with Dyt1 KI mice, Dyt1 heterozygous KO mice showed motor deficits in the beam-walking test. Dyt1 heterozygous KO mice showed decreased hippocampal torsinA levels lower than those in Dyt1 KI mice. Reduced sEPSCs and normal miniature excitatory post-synaptic currents (mEPSCs) were also observed in the acute hippocampal brain slices from Dyt1 heterozygous KO mice, suggesting that the partial loss of torsinA function in Dyt1 KI mice causes action potential-dependent neurotransmitter release deficits. On the other hand, Dyt1 heterozygous KO mice showed enhanced hippocampal LTP, normal input-output relations and paired pulse ratios in the extracellular field recordings. The results suggest that maintaining an appropriate torsinA level is important to sustain normal motor performance, synaptic transmission and plasticity. Developing therapeutics to restore a normal torsinA level may help to prevent and treat the symptoms in DYT1 dystonia.
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Affiliation(s)
- Fumiaki Yokoi
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Huan-Xin Chen
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Mai Tu Dang
- Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Chad C. Cheetham
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Susan L. Campbell
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steven N. Roper
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - J. David Sweatt
- Department of Neurobiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Yuqing Li
- Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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17
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Yokoi F, Dang MT, Liu J, Gandre JR, Kwon K, Yuen R, Li Y. Decreased dopamine receptor 1 activity and impaired motor-skill transfer in Dyt1 ΔGAG heterozygous knock-in mice. Behav Brain Res 2014; 279:202-10. [PMID: 25451552 DOI: 10.1016/j.bbr.2014.11.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 11/21/2014] [Indexed: 01/08/2023]
Abstract
DYT1 dystonia is a movement disorder caused by a trinucleotide deletion (ΔGAG) in DYT1 (TOR1A), corresponding to a glutamic acid loss in the C-terminal region of torsinA. Functional alterations in the basal ganglia circuits have been reported in both DYT1 dystonia patients and rodent models. Dyt1 ΔGAG heterozygous knock-in (KI) mice exhibit motor deficits and decreased striatal dopamine receptor 2 (D2R) binding activity, suggesting a malfunction of the indirect pathway. However, the role of the direct pathway in pathogenesis of dystonia is not yet clear. Here, we report that Dyt1 KI mice exhibit significantly decreased striatal dopamine receptor 1 (D1R) binding activity and D1R protein levels, suggesting the alteration of the direct pathway. The decreased D1R may be caused by translational or post-translational processes since Dyt1 KI mice had normal levels of striatal D1R mRNA and a normal number of striatal neurons expressing D1R. Levels of striatal ionotropic glutamate receptor subunits, dopamine transporter, acetylcholine muscarinic M4 receptor and adenosine A2A receptor were not altered suggesting a specificity of affected polytopic membrane-associated proteins. Contribution of the direct pathway to motor-skill learning has been suggested in another pharmacological rat model injected with a D1R antagonist. In the present study, we developed a novel motor skill transfer test for mice and found deficits in Dyt1 KI mice. Further characterization of both the direct and the indirect pathways in Dyt1 KI mice will aid the development of novel therapeutic drugs.
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Affiliation(s)
- Fumiaki Yokoi
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610-0236, USA
| | - Mai T Dang
- Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jun Liu
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jason R Gandre
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610-0236, USA
| | - Kelly Kwon
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610-0236, USA
| | - Robert Yuen
- Department of Radiology, School of Medicine, Saint Louis University, Saint Louis, MO 63104, USA
| | - Yuqing Li
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610-0236, USA.
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18
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Harata NC. Current Gaps in the Understanding of the Subcellular Distribution of Exogenous and Endogenous Protein TorsinA. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2014; 4:260. [PMID: 25279252 PMCID: PMC4175402 DOI: 10.7916/d8js9nr2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 08/25/2014] [Indexed: 12/01/2022]
Abstract
Background An in-frame deletion leading to the loss of a single glutamic acid residue in the protein torsinA (ΔE-torsinA) results in an inherited movement disorder, DYT1 dystonia. This autosomal dominant disease affects the function of the brain without causing neurodegeneration, by a mechanism that remains unknown. Methods We evaluated the literature regarding the subcellular localization of torsinA. Results Efforts to elucidate the pathophysiological basis of DYT1 dystonia have relied partly on examining the subcellular distribution of the wild-type and mutated proteins. A typical approach is to introduce the human torsinA gene (TOR1A) into host cells and overexpress the protein therein. In both neurons and non-neuronal cells, exogenous wild-type torsinA introduced in this manner has been found to localize mainly to the endoplasmic reticulum, whereas exogenous ΔE-torsinA is predominantly in the nuclear envelope or cytoplasmic inclusions. Although these outcomes are relatively consistent, findings for the localization of endogenous torsinA have been variable, leaving its physiological distribution a matter of debate. Discussion As patients’ cells do not overexpress torsinA proteins, it is important to understand why the reported distributions of the endogenous proteins are inconsistent. We propose that careful optimization of experimental methods will be critical in addressing the causes of the differences among the distributions of endogenous (non-overexpressed) vs. exogenously introduced (overexpressed) proteins.
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Affiliation(s)
- N Charles Harata
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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19
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Groen JL, Ritz K, Warner TT, Baas F, Tijssen MAJ. DRD1 rare variants associated with tardive-like dystonia: a pilot pathway sequencing study in dystonia. Parkinsonism Relat Disord 2014; 20:782-5. [PMID: 24768614 DOI: 10.1016/j.parkreldis.2014.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 04/03/2014] [Accepted: 04/06/2014] [Indexed: 12/14/2022]
Abstract
The dystonias are a clinical heterogeneous group with a complex genetic background. To gain more insight in genetic risk factors in dystonia we used a pathway sequence approach in patients with an extreme dystonia phenotype (n = 26). We assessed all coding and non-coding variants in candidate genes in D1-like subclass of dopamine receptor genes (DRD1, DRD5) and the synaptic vesicle pathway linked to torsinA (TOR1A, STON2, SNAPIN, KLC1 and THAP1), spanning 96 Kb. Two rare missense variants in DRD1 were found: c.68G>A(p.Arg23His) in the screening group and c.776C>A(p.Ser259Tyr) in an additional screen of 15 selected dystonia patients. Genetic burden analysis of DRD1 rare variants in patients (4.8%) versus European American controls from ESP (0.72%) reveals an OR 5.35 (95% CI 1.29-23.1). No rare missense SNVs in the synaptic vesicle pathway were found. Sequencing of TOR1A showed variant enrichment in haplotype 2, possibly accountable for contradictive results in previous association studies. Two new rare SNVs were detected in THAP1, including a nonsense mutation (p.Gln167Ter) and a splice site variant (c.72-1G>A). Screening for rare SNV of candidate pathways in a phenotype extreme population appears to be a promising alternative method to identify genetic risk factors in complex disorders like primary torsion dystonia. These findings indicate a role for rare genetic variation in dopamine processing genes in dystonia pathophysiology.
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Affiliation(s)
- Justus L Groen
- Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Katja Ritz
- Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Tom T Warner
- Department of Clinical Neurosciences, UCL Institute of Neurology, London, UK
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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20
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Bhansali M, Shemshedini L. COP9 subunits 4 and 5 target soluble guanylyl cyclase α1 and p53 in prostate cancer cells. Mol Endocrinol 2014; 28:834-45. [PMID: 24725084 DOI: 10.1210/me.2014-1017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Our laboratory previously has identified soluble guanylyl cyclase α1 (sGCα1) as a direct target of androgen receptor and essential for prostate cancer cell growth via a pathway independent of nitric oxide (NO) signaling. We identified the COP9 signalosome subunit 4 (CSN4) as a novel interacting partner for sGCα1. Importantly, the CSN4-sGCα1 interaction inhibits sGCα1 proteasomal degradation. Consistent with this, disruption of CSN4 led to a significant decrease in prostate cancer cell proliferation, which was significantly but not completely rescued by sGCα1 overexpression, opening the possibility of an additional target of CSN4. Interestingly, immunoprecipitation experiments showed that p53 is found in the CSN4-sGCα1 cytoplasmic protein complex. However, in contrast to sGCα1, p53 protein stability was compromised by CSN4, leading to prostate cancer cell survival and proliferation. Interestingly, we observed that CSN4 was overexpressed in prostate tumors, and its protein level correlates directly with sGCα1 and inversely with p53 proteins, mimicking what was observed in prostate cancer cells. Our data further showed that CSN4 silencing decreased CSN5 protein levels and suggest that the CSN4 effects on sGCα1 and p53 proteins are mediated by CSN5. Lastly, our study showed that caseine kinase-2 (CK2) was involved in regulating p53 and sGCα1 protein stability as determined by both disruption of CK2 expression and inhibition of its kinase activity. Collectively, our study has identified a novel endogenous CSN4-CSN5-CK2 complex with sGCα1and p53 that oppositely controls the stability of these 2 proteins and provides prostate cancer cells an important mechanism for survival and proliferation.
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Affiliation(s)
- Meenakshi Bhansali
- Department of Biological Sciences, University of Toledo, Toledo, Ohio 43606
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21
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Levay K, Slepak VZ. Regulation of Cop9 signalosome activity by the EF-hand Ca2+-binding protein tescalcin. J Cell Sci 2014; 127:2448-59. [PMID: 24659803 DOI: 10.1242/jcs.139592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Ca(2+)-binding protein tescalcin is known to be involved in hematopoietic cell differentiation; however, this mechanism is poorly understood. Here, we identify CSN4 (subunit 4 of the COP9 signalosome) as a novel binding partner of tescalcin. The COP9 signalosome (CSN) is a multiprotein complex that is essential for development in all eukaryotes. This interaction is selective, Ca(2+)-dependent and involves the PCI domain of CSN4 subunit. We then investigated tescalcin and CSN activity in human erythroleukemia HEL and promyelocytic leukemia K562 cells and find that phorbol 12-myristate 13-acetate (PMA)-induced differentiation, resulting in the upregulation of tescalcin, coincides with reduced deneddylation of cullin-1 (Cul1) and stabilization of p27(Kip1) - molecular events that are associated with CSN activity. The knockdown of tescalcin led to an increase in Cul1 deneddylation, expression of F-box protein Skp2 and the transcription factor c-Jun, whereas the levels of cell cycle regulators p27(Kip1) and p53 decreased. These effects are consistent with the hypothesis that tescalcin might play a role as a negative regulator of CSN activity towards Cul1 in the process of induced cell differentiation.
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Affiliation(s)
- Konstantin Levay
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Vladlen Z Slepak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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22
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Ledoux MS, Dauer WT, Warner TT. Emerging common molecular pathways for primary dystonia. Mov Disord 2014; 28:968-81. [PMID: 23893453 DOI: 10.1002/mds.25547] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 12/23/2022] Open
Abstract
The dystonias are a group of hyperkinetic movement disorders whose principal cause is neuron dysfunction at 1 or more interconnected nodes of the motor system. The study of genes and proteins that cause familial dystonia provides critical information about the cellular pathways involved in this dysfunction, which disrupts the motor pathways at the systems level. In recent years study of the increasing number of DYT genes has implicated a number of cell functions that appear to be involved in the pathogenesis of dystonia. A review of the literature published in English-language publications available on PubMed relating to the genetics and cellular pathology of dystonia was performed. Numerous potential pathogenetic mechanisms have been identified. We describe those that fall into 3 emerging thematic groups: cell-cycle and transcriptional regulation in the nucleus, endoplasmic reticulum and nuclear envelope function, and control of synaptic function. © 2013 Movement Disorder Society.
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Affiliation(s)
- Mark S Ledoux
- Department of Neurology, University of Tennessee Health Science Center Memphis, Tennessee 38163, USA
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23
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Pre-synaptic release deficits in a DYT1 dystonia mouse model. PLoS One 2013; 8:e72491. [PMID: 23967309 PMCID: PMC3742515 DOI: 10.1371/journal.pone.0072491] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 07/17/2013] [Indexed: 01/01/2023] Open
Abstract
DYT1 early-onset generalized torsion dystonia (DYT1 dystonia) is an inherited movement disorder caused by mutations in one allele of DYT1 (TOR1A), coding for torsinA. The most common mutation is a trinucleotide deletion (ΔGAG), which causes a deletion of a glutamic acid residue (ΔE) in the C-terminal region of torsinA. Although recent studies using cultured cells suggest that torsinA contributes to protein processing in the secretory pathway, endocytosis, and the stability of synaptic proteins, the nature of how this mutation affects synaptic transmission remains unclear. We previously reported that theta-burst-induced long-term potentiation (LTP) in the CA1 region of the hippocampal slice is not altered in Dyt1 ΔGAG heterozygous knock-in (KI) mice. Here, we examined short-term synaptic plasticity and synaptic transmission in the hippocampal slices. Field recordings in the hippocampal Schaffer collaterals (SC) pathway revealed significantly enhanced paired pulse ratios (PPRs) in Dyt1 ΔGAG heterozygous KI mice, suggesting an impaired synaptic vesicle release. Whole-cell recordings from the CA1 neurons showed that Dyt1 ΔGAG heterozygous KI mice exhibited normal miniature excitatory post-synaptic currents (mEPSC), suggesting that action-potential independent spontaneous pre-synaptic release was normal. On the other hand, there was a significant decrease in the frequency, but not amplitude or kinetics, of spontaneous excitatory post-synaptic currents (sEPSC) in Dyt1 ΔGAG heterozygous KI mice, suggesting that the action-potential dependent pre-synaptic release was impaired. Moreover, hippocampal torsinA was significantly reduced in Dyt1 ΔGAG heterozygous KI mice. Although the hippocampal slice model may not represent the neurons directly associated with dystonic symptoms, impaired release of neurotransmitters caused by partial dysfunction of torsinA in other brain regions may contribute to the pathophysiology of DYT1 dystonia.
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Casper C, Kalliolia E, Warner TT. Recent advances in the molecular pathogenesis of dystonia-plus syndromes and heredodegenerative dystonias. Curr Neuropharmacol 2013; 11:30-40. [PMID: 23814535 PMCID: PMC3580789 DOI: 10.2174/157015913804999432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/17/2012] [Accepted: 08/29/2012] [Indexed: 12/04/2022] Open
Abstract
The majority of studies investigating the molecular pathogenesis and cell biology underlying dystonia have been performed in individuals with primary dystonia. This includes monogenic forms such as DYT1and DYT6 dystonia, and primary focal dystonia which is likely to be multifactorial in origin. In recent years there has been renewed interest in non-primary forms of dystonia including the dystonia-plus syndromes and heredodegenerative disorders. These are caused by a variety of genetic mutations and their study has contributed to our understanding of the neuronal dysfunction that leads to dystonia These findings have reinforced themes identified from study of primary dystonia including abnormal dopaminergic signalling, cellular trafficking and mitochondrial function. In this review we highlight recent advances in the understanding of the dystonia-plus syndromes and heredodegenerative dystonias.
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Affiliation(s)
- Catharina Casper
- Department of Clinical Neurosciences, UCL Institute of Neurology, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
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Puglisi F, Vanni V, Ponterio G, Tassone A, Sciamanna G, Bonsi P, Pisani A, Mandolesi G. Torsin A Localization in the Mouse Cerebellar Synaptic Circuitry. PLoS One 2013; 8:e68063. [PMID: 23840813 PMCID: PMC3686744 DOI: 10.1371/journal.pone.0068063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/24/2013] [Indexed: 11/19/2022] Open
Abstract
Torsin A (TA) is a ubiquitous protein belonging to the superfamily of proteins called "ATPases associated with a variety of cellular activities" (AAA(+) ATPase). To date, a great deal of attention has been focused on neuronal TA since its mutant form causes early-onset (DYT1) torsion dystonia, an inherited movement disorder characterized by sustained muscle contractions and abnormal postures. Interestingly, it has been proposed that TA, by interacting with the cytoskeletal network, may contribute to the control of neurite outgrowth and/or by acting as a chaperone at synapses could affect synaptic vesicle turnover and neurotransmitter release. Accordingly, both its peculiar developmental expression in striatum and cerebellum and evidence from DYT1 knock-in mice suggest that TA may influence dendritic arborization and synaptogenesis in the brain. Therefore, to better understand TA function a detailed description of its localization at synaptic level is required. Here, we characterized by means of rigorous quantitative confocal analysis TA distribution in the mouse cerebellum at postnatal day 14 (P14), when both cerebellar synaptogenesis and TA expression peak. We observed that the protein is broadly distributed both in cerebellar cortex and in the deep cerebellar nuclei (DCN). Of note, Purkinje cells (PC) express high levels of TA also in the spines and axonal terminals. In addition, abundant expression of the protein was found in the main GABA-ergic and glutamatergic inputs of the cerebellar cortex. Finally, TA was observed also in glial cells, a cellular population little explored so far. These results extend our knowledge on TA synaptic localization providing a clue to its potential role in synaptic development.
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Affiliation(s)
- Francesca Puglisi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Valentina Vanni
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Giulia Ponterio
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Annalisa Tassone
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Giuseppe Sciamanna
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Paola Bonsi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
| | - Antonio Pisani
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
- * E-mail:
| | - Georgia Mandolesi
- Department of Systems Medicine, University of Rome Tor Vergata/Laboratory of Neurophysiology and Synaptic Plasticity, Fondazione Santa Lucia, Rome, Italy
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Restani L, Giribaldi F, Manich M, Bercsenyi K, Menendez G, Rossetto O, Caleo M, Schiavo G. Botulinum neurotoxins A and E undergo retrograde axonal transport in primary motor neurons. PLoS Pathog 2012; 8:e1003087. [PMID: 23300443 PMCID: PMC3531519 DOI: 10.1371/journal.ppat.1003087] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 11/02/2012] [Indexed: 11/18/2022] Open
Abstract
The striking differences between the clinical symptoms of tetanus and botulism have been ascribed to the different fate of the parental neurotoxins once internalised in motor neurons. Tetanus toxin (TeNT) is known to undergo transcytosis into inhibitory interneurons and block the release of inhibitory neurotransmitters in the spinal cord, causing a spastic paralysis. In contrast, botulinum neurotoxins (BoNTs) block acetylcholine release at the neuromuscular junction, therefore inducing a flaccid paralysis. Whilst overt experimental evidence supports the sorting of TeNT to the axonal retrograde transport pathway, recent findings challenge the established view that BoNT trafficking is restricted to the neuromuscular junction by highlighting central effects caused by these neurotoxins. These results suggest a more complex scenario whereby BoNTs also engage long-range trafficking mechanisms. However, the intracellular pathways underlying this process remain unclear. We sought to fill this gap by using primary motor neurons either in mass culture or differentiated in microfluidic devices to directly monitor the endocytosis and axonal transport of full length BoNT/A and BoNT/E and their recombinant binding fragments. We show that BoNT/A and BoNT/E are internalised by spinal cord motor neurons and undergo fast axonal retrograde transport. BoNT/A and BoNT/E are internalised in non-acidic axonal carriers that partially overlap with those containing TeNT, following a process that is largely independent of stimulated synaptic vesicle endo-exocytosis. Following intramuscular injection in vivo, BoNT/A and TeNT displayed central effects with a similar time course. Central actions paralleled the peripheral spastic paralysis for TeNT, but lagged behind the onset of flaccid paralysis for BoNT/A. These results suggest that the fast axonal retrograde transport compartment is composed of multifunctional trafficking organelles orchestrating the simultaneous transfer of diverse cargoes from nerve terminals to the soma, and represents a general gateway for the delivery of virulence factors and pathogens to the central nervous system. Botulinum neurotoxins are the most toxic molecules known to mankind, and as a result, are currently listed among the top bio-threats. However, their ability to bind specifically to neurons and their inhibitory effects on regulated secretion prompted their clinical use in pathologies characterised by increased muscular tone, such as dystonia and various forms of spasticity, or abnormal secretion, such as drooling and excessive sweating, to cite a few. As a consequence, botulinum neurotoxin A, which is the serotype most commonly used in human therapy, has become the treatment of choice for an ever-expanding number of pathological and non-pathological (e.g. cosmetic) conditions. All current indications show that the systemic effects and toxicity of botulinum neurotoxin A are minimised by the specific route of administration (local injection) and the low diffusion of this molecule in tissues. However, recent reports suggest that in contrast to this common belief, botulinum neurotoxin A is able to reach distal sites in the body and may have previously unanticipated effects in the central nervous system. In this study, we demonstrate that botulinum neurotoxin A and E enter alternative endocytic pathway(s) in addition to synaptic vesicle recycling, and undergo long-range transport in a non degradative compartment in spinal cord motor neurons. Our results show that axonal retrograde transport is a common pathway for the dissemination in the central nervous system of pathogens and virulence factors important for human and animal health.
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Affiliation(s)
- Laura Restani
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- CNR, Neuroscience Institute, Pisa, Italy
| | - Francesco Giribaldi
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Maria Manich
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Kinga Bercsenyi
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Guillermo Menendez
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- * E-mail:
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Kakazu Y, Koh JY, Iwabuchi S, Gonzalez-Alegre P, Harata NC. Miniature release events of glutamate from hippocampal neurons are influenced by the dystonia-associated protein torsinA. Synapse 2012; 66:807-22. [PMID: 22588999 DOI: 10.1002/syn.21571] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 05/09/2012] [Indexed: 12/23/2022]
Abstract
TorsinA is an evolutionarily conserved AAA+ ATPase, and human patients with an in-frame deletion of a single glutamate (ΔE) codon from the encoding gene suffer from autosomal-dominant, early-onset generalized DYT1 dystonia. Although only 30-40% of carriers of the mutation show overt motor symptoms, most experience enhanced excitability of the central nervous system. The cellular mechanism responsible for this change in excitability is not well understood. Here we show the effects of the ΔE-torsinA mutation on miniature neurotransmitter release from neurons. Neurotransmitter release was characterized in cultured hippocampal neurons obtained from wild-type, heterozygous, and homozygous ΔE-torsinA knock-in mice using two approaches. In the first approach, patch-clamp electrophysiology was used to record glutamate-mediated miniature excitatory postsynaptic currents (mEPSCs) in the presence of the Na⁺ channel blocker tetrodotoxin (TTX) and absence of GABA(A) receptor antagonists. The intervals between mEPSC events were significantly shorter in neurons obtained from the mutant mice than in those obtained from wild-type mice. In the second approach, the miniature exocytosis of synaptic vesicles was detected by imaging the unstimulated release of FM dye from the nerve terminals in the presence of TTX. Cumulative FM dye release was higher in neurons obtained from the mutant mice than in those obtained from wild-type mice. The number of glutamatergic nerve terminals was also assessed, and we found that this number was unchanged in heterozygous relative to wild-type neurons, but slightly increased in homozygous neurons. Notably, in both heterozygous and homozygous neurons, the unitary synaptic charge during each mEPSC event was unchanged. Overall, our results suggest more frequent miniature glutamate release in neurons with ΔE-torsinA mutations. This change may be one of the underlying mechanisms by which the excitability of the central nervous system is enhanced in the context of DYT1 dystonia. Moreover, qualitative differences between heterozygous and homozygous neurons with respect to certain synaptic properties indicate that the abnormalities observed in homozygotes may reflect more than a simple gene dosage effect.
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Affiliation(s)
- Yasuhiro Kakazu
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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28
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Untethering the nuclear envelope and cytoskeleton: biologically distinct dystonias arising from a common cellular dysfunction. Int J Cell Biol 2012; 2012:634214. [PMID: 22611399 PMCID: PMC3352338 DOI: 10.1155/2012/634214] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/12/2011] [Accepted: 01/08/2012] [Indexed: 12/31/2022] Open
Abstract
Most cases of early onset DYT1 dystonia in humans are caused by a GAG deletion in the TOR1A gene leading to loss of a glutamic acid (ΔE) in the torsinA protein, which underlies a movement disorder associated with neuronal dysfunction without apparent neurodegeneration. Mutation/deletion of the gene (Dst) encoding dystonin in mice results in a dystonic movement disorder termed dystonia musculorum, which resembles aspects of dystonia in humans. While torsinA and dystonin proteins do not share modular domain architecture, they participate in a similar function by modulating a structural link between the nuclear envelope and the cytoskeleton in neuronal cells. We suggest that through a shared interaction with the nuclear envelope protein nesprin-3α, torsinA and the neuronal dystonin-a2 isoform comprise a bridge complex between the outer nuclear membrane and the cytoskeleton, which is critical for some aspects of neuronal development and function. Elucidation of the overlapping roles of torsinA and dystonin-a2 in nuclear/endoplasmic reticulum dynamics should provide insights into the cellular mechanisms underlying the dystonic phenotype.
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Fernández-Alvarez E, Nardocci N. Update on pediatric dystonias: etiology, epidemiology, and management. Degener Neurol Neuromuscul Dis 2012; 2:29-41. [PMID: 30890876 DOI: 10.2147/dnnd.s16082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dystonia is a movement disorder characterized by sustained muscle contractions producing twisting, repetitive, and patterned movements or abnormal postures. Dystonia is among the most commonly observed movement disorders in clinical practice both in adults and children. It is classified on the basis of etiology, age at onset of symptoms, and distribution of affected body regions. Etiology The etiology of pediatric dystonia is quite heterogeneous. There are many different genetic syndromes and several causes of symptomatic syndromes. Dystonia can be secondary to virtually any pathological process that affects the motor system, and particularly the basal ganglia. Classification The etiological classification distinguishes primary dystonia with no identifiable exogenous cause or evidence of neurodegeneration and secondary syndromes. Treatment Treatment for most forms of dystonia is symptomatic and includes drugs (systemic or focal treatments, such as botulinum toxin) and surgical procedures. There are several medications including anticholinergic, dopamine-blocking and depleting agents, baclofen, and benzodiazepines. In patients with dopamine synthesis defects L-dopa treatment may be very useful. Botulinum toxin treatment may be helpful in controlling the most disabling symptoms of segmental or focal dystonia. Long-term electrical stimulation of the globus pallidum internum appears to be especially successful in children suffering from generalized dystonia.
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Affiliation(s)
| | - Nardo Nardocci
- Child Neurology Department, Fondazione IRCCS Istituto Neurologico "C. Besta", Milano, Italy
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Kakazu Y, Koh JY, Ho KWD, Gonzalez-Alegre P, Harata NC. Synaptic vesicle recycling is enhanced by torsinA that harbors the DYT1 dystonia mutation. Synapse 2012; 66:453-64. [PMID: 22213465 DOI: 10.1002/syn.21534] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 11/20/2011] [Accepted: 12/17/2011] [Indexed: 11/08/2022]
Abstract
Early-onset generalized dystonia, DYT1, is caused by a mutation in the gene encoding the evolutionarily conserved AAA+ ATPase torsinA. Synaptic abnormalities have been implicated in DYT1 dystonia, but the details of the synaptic pathophysiology are only partially understood. Here, we demonstrate a novel role for torsinA in synaptic vesicle recycling, using cultured hippocampal neurons from a knock-in mouse model of DYT1 dystonia (ΔE-torsinA) and live-cell imaging with styryl FM dyes. Neurons from heterozygous ΔE-torsinA mice released a larger fraction of the total recycling pool (TRP) during a single round of electrical stimulation than did wild-type neurons. Moreover, when the neurons were subjected to prior high activity, the time course of release was shortened. In neurons from homozygous mice, these enhanced exocytosis phenotypes were similar, but in addition the size of the TRP was reduced. Notably, when release was triggered by applying a calcium ionophore rather than electrical stimuli, neither a single nor two ΔE-torsinA alleles affected the time course of release. Thus, the site of action of ΔE-torsinA is at or upstream of the rise in calcium concentration in nerve terminals. Our results suggest that torsinA regulates synaptic vesicle recycling in central neurons. They also indicate that this regulation is influenced by neuronal activity, further supporting the idea that synaptic abnormalities contribute to the pathophysiology of DYT1 dystonia.
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Affiliation(s)
- Yasuhiro Kakazu
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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31
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Schapira AHV, Hillbom M. Publishing changes and information delivery in the clinical neurosciences. Eur J Neurol 2011. [DOI: 10.1111/j.1468-1331.2011.03594.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Phukan J, Albanese A, Gasser T, Warner T. Primary dystonia and dystonia-plus syndromes: clinical characteristics, diagnosis, and pathogenesis. Lancet Neurol 2011; 10:1074-85. [PMID: 22030388 DOI: 10.1016/s1474-4422(11)70232-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The dystonias are a heterogeneous group of hyperkinetic movement disorders characterised by involuntary sustained muscle contractions that lead to abnormal postures and repetitive movements. Dystonia syndromes represent common movement disorders and yet are often misdiagnosed or unrecognised. In recent years, there have been substantial advances in the understanding of the spectrum of clinical features that encompass dystonia syndromes, from severe generalised childhood dystonia that is often genetic in origin, to adult-onset focal dystonias and rarer forms of secondary dystonias, to dystonia as a feature of other types of CNS dysfunction. There has also been a rationalisation of the classification of dystonia and a greater understanding of the causes of dystonic movements from the study of genetics, neurophysiology, and functional imaging in the most prevalent form of dystonia syndrome, primary dystonia.
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Affiliation(s)
- Julie Phukan
- Department of Clinical Neurosciences, UCL Institute of Neurology, Royal Free Campus, London, UK
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33
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Lalli S, Canavese C, Zorzi G, Nardocci N, Albanese A. Diagnostic issues in childhood and adult dystonia. ACTA ACUST UNITED AC 2011; 5:483-500. [DOI: 10.1517/17530059.2011.615831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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34
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Li W, Zang B, Liu C, Lu L, Wei N, Cao K, Deng XW, Wang X. TSA1 interacts with CSN1/CSN and may be functionally involved in Arabidopsis seedling development in darkness. J Genet Genomics 2011; 38:539-46. [PMID: 22133685 DOI: 10.1016/j.jgg.2011.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 08/03/2011] [Accepted: 08/04/2011] [Indexed: 01/30/2023]
Abstract
The COP9 signalosome (CSN) is a multiprotein complex which participates in diverse cellular and developmental processes. CSN1, one of the subunits of CSN, is essential for assembly of the multiprotein complex via PCI (proteasome, COP9 signalosome and initiation factor 3) domain in the C-terminal half of CSN1. However, the role of the N-terminal domain (NTD) of CSN1, which is critical for the function of CSN, is not completely understood. Using a yeast two-hybrid (Y2H) screen, we found that the NTD of CSN1 interacts with TSK-associating protein 1 (TSA1), a reported Ca(2+)-binding protein. The interaction between CSN1 and TSA1 was confirmed by co-immunoprecipitation in Arabidopsis. tsa1 mutants exhibited a short hypocotyl phenotype in darkness but were similar to wild-type Arabidopsis under white light, which suggested that TSA1 might regulate Arabidopsis hypocotyl development in the dark. Furthermore, the expression of TSA1 was significantly lower in a csn1 null mutant (fus6), while CSN1 expression did not change in a tsa1 mutant with weak TSA1 expression. Together, these findings suggest a functional relationship between TSA1 and CSN1 in seedling development.
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Affiliation(s)
- Wenjun Li
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, Fudan University, Shanghai, China
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