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Islam MR, Jony MH, Thufa GK, Akash S, Dhar PS, Rahman MM, Afroz T, Ahmed M, Hemeg HA, Rauf A, Thiruvengadam M, Venkidasamy B. A clinical study and future prospects for bioactive compounds and semi-synthetic molecules in the therapies for Huntington's disease. Mol Neurobiol 2024; 61:1237-1270. [PMID: 37698833 DOI: 10.1007/s12035-023-03604-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/21/2023] [Indexed: 09/13/2023]
Abstract
A neurodegenerative disorder (ND) refers to Huntington's disease (HD) which affects memory loss, weight loss, and movement dysfunctions such as chorea and dystonia. In the striatum and brain, HD most typically impacts medium-spiny neurons. Molecular genetics, excitotoxicity, oxidative stress (OS), mitochondrial, and metabolic dysfunction are a few of the theories advanced to explicit the pathophysiology of neuronal damage and cell death. Numerous in-depth studies of the literature have supported the therapeutic advantages of natural products in HD experimental models and other treatment approaches. This article briefly discusses the neuroprotective impacts of natural compounds against HD models. The ability of the discovered natural compounds to suppress HD was tested using either in vitro or in vivo models. Many bioactive compounds considerably lessened the memory loss and motor coordination brought on by 3-nitropropionic acid (3-NP). Reduced lipid peroxidation, increased endogenous enzymatic antioxidants, reduced acetylcholinesterase activity, and enhanced mitochondrial energy generation have profoundly decreased the biochemical change. It is significant since histology showed that therapy with particular natural compounds lessened damage to the striatum caused by 3-NP. Moreover, natural products displayed varying degrees of neuroprotection in preclinical HD studies because of their antioxidant and anti-inflammatory properties, maintenance of mitochondrial function, activation of autophagy, and inhibition of apoptosis. This study highlighted about the importance of bioactive compounds and their semi-synthetic molecules in the treatment and prevention of HD.
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Affiliation(s)
- Md Rezaul Islam
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Maruf Hossain Jony
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Gazi Kaifeara Thufa
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Shopnil Akash
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Puja Sutra Dhar
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Md Mominur Rahman
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Tahmina Afroz
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Muniruddin Ahmed
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, 1207, Dhaka, Bangladesh
| | - Hassan A Hemeg
- Department of Medical Laboratory Technology, College of Applied Medical Sciences, Taibah University, Al-Medinah Al-Monawara, Saudi Arabia
| | - Abdur Rauf
- Department of Chemistry, University of Swabi, Swabi, Khyber Pukhtanukha, Pakistan.
| | - Muthu Thiruvengadam
- Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul, 05029, South Korea.
| | - Baskar Venkidasamy
- Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, 600 077, India.
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García-García E, Ramón-Lainez A, Conde-Berriozabal S, Del Toro D, Escaramis G, Giralt A, Masana M, Alberch J, Rodríguez MJ. VPS13A knockdown impairs corticostriatal synaptic plasticity and locomotor behavior in a new mouse model of chorea-acanthocytosis. Neurobiol Dis 2023; 187:106292. [PMID: 37714309 DOI: 10.1016/j.nbd.2023.106292] [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: 07/28/2023] [Revised: 09/01/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023] Open
Abstract
Chorea-acanthocytosis (ChAc) is an inherited neurodegenerative movement disorder caused by VPS13A gene mutations leading to the absence of protein expression. The striatum is the most affected brain region in ChAc patients. However, the study of the VPS13A function in the brain has been poorly addressed. Here we generated a VPS13A knockdown (KD) model and aimed to elucidate the contribution of VPS13A to synaptic plasticity and neuronal communication in the corticostriatal circuit. First, we infected primary cortical neurons with miR30-shRNA against VPS13A and analyzed its effects on neuronal plasticity. VPS13A-KD neurons showed a higher degree of branching than controls, accompanied by decreased BDNF and PSD-95 levels, indicative of synaptic alterations. We then injected AAV-KD bilaterally in the frontal cortex and two different regions of the striatum of mice and analyzed the effects of VPS13A-KD on animal behavior and synaptic plasticity. VPS13A-KD mice showed modification of the locomotor behavior pattern, with increased exploratory behavior and hyperlocomotion. Corticostriatal dysfunction in VPS13A-KD mice was evidenced by impaired striatal long-term depression (LTD) after stimulation of cortical afferents, which was partially recovered by BDNF administration. VPS13A-KD did not lead to neuronal loss in the cortex or the striatum but induced a decrease in the neuronal release of CX3CL1 and triggered a microglial reaction, especially in the striatum. Notably, CX3CL1 administration partially restored the impaired corticostriatal LTD in VPS13A-KD mice. Our results unveil the involvement of VPS13A in neuronal connectivity modifying BDNF and CX3CL1 release. Moreover, the involvement of VPS13A in synaptic plasticity and motor behavior provides key information to further understand not only ChAc pathophysiology but also other neurological disorders.
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Affiliation(s)
- Esther García-García
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Alba Ramón-Lainez
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Sara Conde-Berriozabal
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Daniel Del Toro
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Georgia Escaramis
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; Biomedical Research Networking Center for Epidemiology and Public Health (CIBERESP), Ministerio de Ciencia e Innovación, Madrid, Spain.
| | - Albert Giralt
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Mercè Masana
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
| | - Jordi Alberch
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, University of Barcelona, E-08036 Barcelona, Spain.
| | - Manuel J Rodríguez
- Dept Biomedical Sciences, School of Medicine and Health Sciences, Institute of Neurosciences, Universitat de Barcelona, E-08036 Barcelona, Spain; August Pi i Sunyer Biomedical Research Institute (IDIBAPS), E-08036 Barcelona, Spain; Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), E-08036 Barcelona, Spain.
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Roth JR, de Moraes RCM, Xu BP, Crawley SR, Khan MA, Melkani GC. Rapamycin reduces neuronal mutant huntingtin aggregation and ameliorates locomotor performance in Drosophila. Front Aging Neurosci 2023; 15:1223911. [PMID: 37823007 PMCID: PMC10562706 DOI: 10.3389/fnagi.2023.1223911] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 09/05/2023] [Indexed: 10/13/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease characterized by movement and cognitive dysfunction. HD is caused by a CAG expansion in exon 1 of the HTT gene that leads to a polyglutamine (PQ) repeat in the huntingtin protein, which aggregates in the brain and periphery. Previously, we used Drosophila models to determine that Htt-PQ aggregation in the heart causes shortened lifespan and cardiac dysfunction that is ameliorated by promoting chaperonin function or reducing oxidative stress. Here, we further study the role of neuronal mutant huntingtin and how it affects peripheral function. We overexpressed normal (Htt-PQ25) or expanded mutant (Htt-PQ72) exon 1 of huntingtin in Drosophila neurons and found that mutant huntingtin caused age-dependent Htt-PQ aggregation in the brain and could cause a loss of synapsin. To determine if this neuronal dysfunction led to peripheral dysfunction, we performed a negative geotaxis assay to measure locomotor performance and found that neuronal mutant huntingtin caused an age-dependent decrease in locomotor performance. Next, we found that rapamycin reduced Htt-PQ aggregation in the brain. These results demonstrate the role of neuronal Htt-PQ in dysfunction in models of HD, suggest that brain-periphery crosstalk could be important to the pathogenesis of HD, and show that rapamycin reduces mutant huntingtin aggregation in the brain.
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Affiliation(s)
- Jonathan R. Roth
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ruan Carlos Macedo de Moraes
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Brittney P. Xu
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Savannah R. Crawley
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Malghalara A. Khan
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Girish C. Melkani
- Department of Pathology, Cellular and Molecular Division, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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Speidell A, Walton S, Campbell LA, Tomassoni-Ardori F, Tessarollo L, Corbo C, Taraballi F, Mocchetti I. Mice deficient for G-protein-coupled receptor 75 display altered presynaptic structural protein expression and disrupted fear conditioning recall. J Neurochem 2023; 165:827-841. [PMID: 36978267 PMCID: PMC10330141 DOI: 10.1111/jnc.15818] [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: 10/11/2022] [Revised: 03/23/2023] [Accepted: 03/26/2023] [Indexed: 03/30/2023]
Abstract
There are a number of G-protein-coupled receptors (GPCRs) that are considered "orphan receptors" because the information on their known ligands is incomplete. Yet, these receptors are important targets to characterize, as the discovery of their ligands may lead to potential new therapies. GPR75 was recently deorphanized because at least two ligands appear to bind to it, the chemokine CCL5 and the eicosanoid 20-Hydroxyeicosatetraenoic acid. Recent reports suggest that GPR75 may play a role in regulating insulin secretion and obesity. However, little is known about the function of this receptor in the brain. To study the function of GPR75, we have generated a knockout (KO) mouse model of this receptor and we evaluated the role that this receptor plays in the adult hippocampus by an array of histological, proteomic, and behavioral endpoints. Using RNAscope® technology, we identified GPR75 puncta in several Rbfox3-/NeuN-positive cells in the hippocampus, suggesting that this receptor has a neuronal expression. Proteomic analysis of the hippocampus in 3-month-old GPR75 KO animals revealed that several markers of synapses, including synapsin I and II are downregulated compared with wild type (WT). To examine the functional consequence of this down-regulation, WT and GPR75 KO mice were tested on a hippocampal-dependent behavioral task. Both contextual memory and anxiety-like behaviors were significantly altered in GPR75 KO, suggesting that GPR75 plays a role in hippocampal activity.
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Affiliation(s)
- Andrew Speidell
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Washington, DC
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC
| | - Sofia Walton
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Washington, DC
| | - Lee A Campbell
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Washington, DC
| | | | | | - Claudia Corbo
- School of Medicine and Surgery Nanomedicine Center, University of Milano-Bicocca, Milan, Italy
- IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - Francesca Taraballi
- Center for Musculoskeletal Regeneration, Houston Methodist Research Institute
- Orthopedics and Sports Medicine, Houston Methodist Hospital, Houston, TX
| | - Italo Mocchetti
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Washington, DC
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC
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5
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Longhena F, Faustini G, Brembati V, Pizzi M, Benfenati F, Bellucci A. An updated reappraisal of synapsins: structure, function and role in neurological and psychiatric disorders. Neurosci Biobehav Rev 2021; 130:33-60. [PMID: 34407457 DOI: 10.1016/j.neubiorev.2021.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023]
Abstract
Synapsins (Syns) are phosphoproteins strongly involved in neuronal development and neurotransmitter release. Three distinct genes SYN1, SYN2 and SYN3, with elevated evolutionary conservation, have been described to encode for Synapsin I, Synapsin II and Synapsin III, respectively. Syns display a series of common features, but also exhibit distinctive localization, expression pattern, post-translational modifications (PTM). These characteristics enable their interaction with other synaptic proteins, membranes and cytoskeletal components, which is essential for the proper execution of their multiple functions in neuronal cells. These include the control of synapse formation and growth, neuron maturation and renewal, as well as synaptic vesicle mobilization, docking, fusion, recycling. Perturbations in the balanced expression of Syns, alterations of their PTM, mutations and polymorphisms of their encoding genes induce severe dysregulations in brain networks functions leading to the onset of psychiatric or neurological disorders. This review presents what we have learned since the discovery of Syn I in 1977, providing the state of the art on Syns structure, function, physiology and involvement in central nervous system disorders.
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Affiliation(s)
- Francesca Longhena
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Viviana Brembati
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Marina Pizzi
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Fabio Benfenati
- Italian Institute of Technology, Via Morego 30, Genova, Italy; IRCSS Policlinico San Martino Hospital, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Laboratory for Preventive and Personalized Medicine, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
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6
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Lum PT, Sekar M, Gan SH, Bonam SR, Shaikh MF. Protective Effect of Natural Products against Huntington's Disease: An Overview of Scientific Evidence and Understanding Their Mechanism of Action. ACS Chem Neurosci 2021; 12:391-418. [PMID: 33475334 DOI: 10.1021/acschemneuro.0c00824] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Huntington's disease (HD), a neurodegenerative disease, normally starts in the prime of adult life, followed by a gradual occurrence of characteristic psychiatric disturbances and cognitive and motor dysfunction. To the best of our knowledge, there is no treatment available to completely mitigate the progression of HD. Among various therapeutic approaches, exhaustive literature reports have confirmed the medicinal benefits of natural products in HD experimental models. Building on this information, this review presents a brief overview of the neuroprotective mechanism(s) of natural products against in vitro/in vivo models of HD. Relevant studies were identified from several scientific databases, including PubMed, ScienceDirect, Scopus, and Google Scholar. After screening through literature from 2005 to the present, a total of 14 medicinal plant species and 30 naturally isolated compounds investigated against HD based on either in vitro or in vivo models were included in the present review. Behavioral outcomes in the HD in vivo model showed that natural compounds significantly attenuated 3-nitropropionic acid (3-NP) induced memory loss and motor incoordination. The biochemical alteration has been markedly alleviated with reduced lipid peroxidation, increased endogenous enzymatic antioxidants, reduced acetylcholinesterase activity, and increased mitochondrial energy production. Interestingly, following treatment with certain natural products, 3-NP-induced damage in the striatum was ameliorated, as seen histologically. Overall, natural products afforded varying degrees of neuroprotection in preclinical studies of HD via antioxidant and anti-inflammatory properties, preservation of mitochondrial function, inhibition of apoptosis, and induction of autophagy.
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Affiliation(s)
- Pei Teng Lum
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, Ipoh, 30450 Perak, Malaysia
| | - Mahendran Sekar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, Ipoh, 30450 Perak, Malaysia
| | - Siew Hua Gan
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia
| | - Srinivasa Reddy Bonam
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, Paris 75006, France
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, 47500 Selangor, Malaysia
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Skotte NH, Andersen JV, Santos A, Aldana BI, Willert CW, Nørremølle A, Waagepetersen HS, Nielsen ML. Integrative Characterization of the R6/2 Mouse Model of Huntington's Disease Reveals Dysfunctional Astrocyte Metabolism. Cell Rep 2019; 23:2211-2224. [PMID: 29768217 DOI: 10.1016/j.celrep.2018.04.052] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/23/2018] [Accepted: 04/12/2018] [Indexed: 01/05/2023] Open
Abstract
Huntington's disease is a fatal neurodegenerative disease, where dysfunction and loss of striatal and cortical neurons are central to the pathogenesis of the disease. Here, we integrated quantitative studies to investigate the underlying mechanisms behind HD pathology in a systems-wide manner. To this end, we used state-of-the-art mass spectrometry to establish a spatial brain proteome from late-stage R6/2 mice and compared this with wild-type littermates. We observed altered expression of proteins in pathways related to energy metabolism, synapse function, and neurotransmitter homeostasis. To support these findings, metabolic 13C labeling studies confirmed a compromised astrocytic metabolism and regulation of glutamate-GABA-glutamine cycling, resulting in impaired release of glutamine and GABA synthesis. In recent years, increasing attention has been focused on the role of astrocytes in HD, and our data support that therapeutic strategies to improve astrocytic glutamine homeostasis may help ameliorate symptoms in HD.
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Affiliation(s)
- Niels H Skotte
- Proteomics Program, The Novo Nordisk Foundation Centre for Protein Research, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens V Andersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alberto Santos
- Proteomics Program, The Novo Nordisk Foundation Centre for Protein Research, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Blanca I Aldana
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cecilie W Willert
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Nørremølle
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael L Nielsen
- Proteomics Program, The Novo Nordisk Foundation Centre for Protein Research, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.
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Mohseni Ahooyi T, Torkzaban B, Shekarabi M, Tahrir FG, Decoppet EA, Cotto B, Langford D, Amini S, Khalili K. Perturbation of synapsins homeostasis through HIV-1 Tat-mediated suppression of BAG3 in primary neuronal cells. Cell Death Dis 2019; 10:473. [PMID: 31209204 PMCID: PMC6572798 DOI: 10.1038/s41419-019-1702-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/06/2019] [Accepted: 03/14/2019] [Indexed: 02/02/2023]
Abstract
HIV-1 Tat is known to be released by HIV infected non-neuronal cells in the brain, and after entering neurons, compromises brain homeostasis by impairing pro-survival pathways, thus contributing to the development of HIV-associated CNS disorders commonly observed in individuals living with HIV. Here, we demonstrate that synapsins, phosphoproteins that are predominantly expressed in neuronal cells and play a vital role in modulating neurotransmitter release at the pre-synaptic terminal, and neuronal differentiation become targets for Tat through autophagy and protein quality control pathways. We demonstrate that the presence of Tat in neurons results in downregulation of BAG3, a co-chaperone for heat shock proteins (Hsp70/Hsc70) that is implicated in protein quality control (PQC) processes by eliminating mis-folded and damaged proteins, and selective macroautophagy. Our results show that treatment of cells with Tat or suppression of BAG3 expression by siRNA in neuronal cells disturbs subcellular distribution of synapsins and synaptotagmin 1 (Syt1) leading to their accumulation in the neuronal soma and along axons in a punctate pattern, rather than being properly distributed at axon-terminals. Further, our results revealed that synapsins partially lost their stability and their removal via lysosomal autophagy was noticeably impaired in cells with low levels of BAG3. The observed impairment of lysosomal autophagy, under this condition, is likely caused by cells losing their ability to process LC3-I to LC3-II, in part due to a decrease in the ATG5 levels upon BAG3 knockdown. These observations ascribe a new function for BAG3 in controlling synaptic communications and illuminate a new downstream target for Tat to elicit its pathogenic effect in impacting neuronal cell function and behavior.
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Affiliation(s)
- Taha Mohseni Ahooyi
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA.
| | - Bahareh Torkzaban
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Masoud Shekarabi
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Farzaneh G Tahrir
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Emilie A Decoppet
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Bianca Cotto
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Dianne Langford
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Shohreh Amini
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA
| | - Kamel Khalili
- Department of Neuroscience Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500N. Broad Street, Philadelphia, PA, 19140, USA.
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9
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Chen S, Yu C, Rong L, Li CH, Qin X, Ryu H, Park H. Altered Synaptic Vesicle Release and Ca 2+ Influx at Single Presynaptic Terminals of Cortical Neurons in a Knock-in Mouse Model of Huntington's Disease. Front Mol Neurosci 2018; 11:478. [PMID: 30618623 PMCID: PMC6311661 DOI: 10.3389/fnmol.2018.00478] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/06/2018] [Indexed: 12/21/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the huntingtin (HTT) gene, which leads to progressive loss of neurons starting in the striatum and cortex. One possible mechanism for this selective loss of neurons in the early stage of HD is altered neurotransmission at synapses. Despite the recent finding that presynaptic terminals play an important role in HD, neurotransmitter release at synapses in HD remains poorly understood. Here, we measured synaptic vesicle release in real time at single presynaptic terminals during electrical field stimulation. We found the increase in synaptic vesicle release at presynaptic terminals in primary cortical neurons in a knock-in mouse model of HD (zQ175). We also found the increase in Ca2+ influx at presynaptic terminals in HD neurons during the electrical stimulation. Consistent with increased Ca2+-dependent neurotransmission in HD neurons, the increase in vesicle release and Ca2+ influx was rescued with Ca2+ chelators or by blocking N-type voltage-gated Ca2+ channels, suggesting N-type voltage-gated Ca2+ channels play an important role in HD. Taken together, our results suggest that the increased synaptic vesicles release due to increased Ca2+ influx at presynaptic terminals in cortical neurons contributes to the selective neurodegeneration of these neurons in early HD and provide a possible therapeutic target.
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Affiliation(s)
- Sidong Chen
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Chenglong Yu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Li Rong
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Chun Hei Li
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Xianan Qin
- Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Hoon Ryu
- Department of Neurology, Boston University School of Medicine, Boston, MA, United States
| | - Hyokeun Park
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong.,Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong.,State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
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10
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Mirza FJ, Zahid S. The Role of Synapsins in Neurological Disorders. Neurosci Bull 2017; 34:349-358. [PMID: 29282612 DOI: 10.1007/s12264-017-0201-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 10/27/2017] [Indexed: 12/12/2022] Open
Abstract
Synapsins serve as flagships among the presynaptic proteins due to their abundance on synaptic vesicles and contribution to synaptic communication. Several studies have emphasized the importance of this multi-gene family of neuron-specific phosphoproteins in maintaining brain physiology. In the recent times, increasing evidence has established the relevance of alterations in synapsins as a major determinant in many neurological disorders. Here, we give a comprehensive description of the diverse roles of the synapsin family and the underlying molecular mechanisms that contribute to several neurological disorders. These physiologically important roles of synapsins associated with neurological disorders are just beginning to be understood. A detailed understanding of the diversified expression of synapsins may serve to strategize novel therapeutic approaches for these debilitating neurological disorders.
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Affiliation(s)
- Fatima Javed Mirza
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Saadia Zahid
- Neurobiology Research Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
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11
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Chen G, Ma Q, Goswami D, Shang J, Miller GM. Modulation of nuclear REST by alternative splicing: a potential therapeutic target for Huntington's disease. J Cell Mol Med 2017; 21:2974-2984. [PMID: 28524599 PMCID: PMC5661251 DOI: 10.1111/jcmm.13209] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/22/2017] [Indexed: 02/06/2023] Open
Abstract
Huntington's disease (HD) is caused by a genetically mutated huntingtin (mHtt) protein with expanded polyQ stretch, which impairs cytosolic sequestration of the repressor element-1 silencing transcription factor (REST), resulting in excessive nuclear REST and subsequent repression of neuronal genes. We recently demonstrated that REST undergoes extensive, context-dependent alternative splicing, of which exon-3 skipping (∆E3 )-a common event in human and nonhuman primates-causes loss of a motif critical for REST nuclear targeting. This study aimed to determine whether ∆E3 can be targeted to reduce nuclear REST and rescue neuronal gene expression in mouse striatal-derived, mHtt-expressing STHdhQ111/Q111 cells-a well-established cellular model of HD. We designed two morpholino antisense oligos (ASOs) targeting the splice sites of Rest E3 and examined their effects on ∆E3 , nuclear Rest accumulation and Rest-controlled gene expression in STHdhQ111/Q111 cells. We found that (1) the ASOs treatment significantly induced ∆E3 , reduced nuclear Rest, and rescued transcription and/or mis-splicing of specific neuronal genes (e.g. Syn1 and Stmn2) in STHdhQ111/Q111 cells; and (2) the ASOs-induced transcriptional regulation was dependent on ∆E3 induction and mimicked by siRNA-mediated knock-down of Rest expression. Our findings demonstrate modulation of nuclear REST by ∆E3 and its potential as a new therapeutic target for HD and provide new insights into environmental regulation of genome function and pathogenesis of HD. As ∆E3 is modulated by cellular signalling and linked to various types of cancer, we anticipate that ∆E3 contributes to environmentally tuned REST function and may have a broad range of clinical implications.
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Affiliation(s)
- Guo‐Lin Chen
- Department of Pharmaceutical Sciences and Center for Drug DiscoverySchool of PharmacyNortheastern UniversityBostonMAUSA
- Guangxi Collaborative Innovation Center for BiomedicineGuangxi Medical UniversityNanningGuangxiChina
- Research Center for Regenerative Medicine of GuangxiGuangxi Medical UniversityNanningGuangxiChina
| | - Qi Ma
- Department of PsychiatryInstitute for Human PerformanceSUNY Upstate Medical UniversitySyracuseNYUSA
| | - Dharmendra Goswami
- Center for the Study of Traumatic EncephalopathyBoston University School of MedicineBostonMAUSA
- Department of NeurologyBoston University School of MedicineBostonMAUSA
- VA Boston HealthCare SystemBostonMAUSA
| | - Jianyu Shang
- Department of Pharmaceutical Sciences and Center for Drug DiscoverySchool of PharmacyNortheastern UniversityBostonMAUSA
| | - Gregory M. Miller
- Department of Pharmaceutical Sciences and Center for Drug DiscoverySchool of PharmacyNortheastern UniversityBostonMAUSA
- Department of Chemical EngineeringSchool of EngineeringNortheastern UniversityBostonMAUSA
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12
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Silva FR, Miranda AS, Santos RP, Olmo IG, Zamponi GW, Dobransky T, Cruz JS, Vieira LB, Ribeiro FM. N-type Ca2+ channels are affected by full-length mutant huntingtin expression in a mouse model of Huntington's disease. Neurobiol Aging 2017; 55:1-10. [DOI: 10.1016/j.neurobiolaging.2017.03.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/06/2017] [Accepted: 03/09/2017] [Indexed: 11/30/2022]
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13
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Li YC, Kavalali ET. Synaptic Vesicle-Recycling Machinery Components as Potential Therapeutic Targets. Pharmacol Rev 2017; 69:141-160. [PMID: 28265000 DOI: 10.1124/pr.116.013342] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Presynaptic nerve terminals are highly specialized vesicle-trafficking machines. Neurotransmitter release from these terminals is sustained by constant local recycling of synaptic vesicles independent from the neuronal cell body. This independence places significant constraints on maintenance of synaptic protein complexes and scaffolds. Key events during the synaptic vesicle cycle-such as exocytosis and endocytosis-require formation and disassembly of protein complexes. This extremely dynamic environment poses unique challenges for proteostasis at synaptic terminals. Therefore, it is not surprising that subtle alterations in synaptic vesicle cycle-associated proteins directly or indirectly contribute to pathophysiology seen in several neurologic and psychiatric diseases. In contrast to the increasing number of examples in which presynaptic dysfunction causes neurologic symptoms or cognitive deficits associated with multiple brain disorders, synaptic vesicle-recycling machinery remains an underexplored drug target. In addition, irrespective of the involvement of presynaptic function in the disease process, presynaptic machinery may also prove to be a viable therapeutic target because subtle alterations in the neurotransmitter release may counter disease mechanisms, correct, or compensate for synaptic communication deficits without the need to interfere with postsynaptic receptor signaling. In this article, we will overview critical properties of presynaptic release machinery to help elucidate novel presynaptic avenues for the development of therapeutic strategies against neurologic and neuropsychiatric disorders.
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Affiliation(s)
- Ying C Li
- Departments of Neuroscience (Y.C.L., E.T.K.) and Physiology (E.T.K.), University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ege T Kavalali
- Departments of Neuroscience (Y.C.L., E.T.K.) and Physiology (E.T.K.), University of Texas Southwestern Medical Center, Dallas, Texas
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14
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Tyebji S, Hannan AJ. Synaptopathic mechanisms of neurodegeneration and dementia: Insights from Huntington's disease. Prog Neurobiol 2017; 153:18-45. [PMID: 28377290 DOI: 10.1016/j.pneurobio.2017.03.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 03/19/2017] [Accepted: 03/30/2017] [Indexed: 12/20/2022]
Abstract
Dementia encapsulates a set of symptoms that include loss of mental abilities such as memory, problem solving or language, and reduces a person's ability to perform daily activities. Alzheimer's disease is the most common form of dementia, however dementia can also occur in other neurological disorders such as Huntington's disease (HD). Many studies have demonstrated that loss of neuronal cell function manifests pre-symptomatically and thus is a relevant therapeutic target to alleviate symptoms. Synaptopathy, the physiological dysfunction of synapses, is now being approached as the target for many neurological and psychiatric disorders, including HD. HD is an autosomal dominant and progressive degenerative disorder, with clinical manifestations that encompass movement, cognition, mood and behaviour. HD is one of the most common tandem repeat disorders and is caused by a trinucleotide (CAG) repeat expansion, encoding an extended polyglutamine tract in the huntingtin protein. Animal models as well as human studies have provided detailed, although not exhaustive, evidence of synaptic dysfunction in HD. In this review, we discuss the neuropathology of HD and how the changes in synaptic signalling in the diseased brain lead to its symptoms, which include dementia. Here, we review and discuss the mechanisms by which the 'molecular orchestras' and their 'synaptic symphonies' are disrupted in neurodegeneration and dementia, focusing on HD as a model disease. We also explore the therapeutic strategies currently in pre-clinical and clinical testing that are targeted towards improving synaptic function in HD.
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Affiliation(s)
- Shiraz Tyebji
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia.
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15
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Gratuze M, Cisbani G, Cicchetti F, Planel E. Is Huntington's disease a tauopathy? Brain 2016; 139:1014-25. [DOI: 10.1093/brain/aww021] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/08/2016] [Indexed: 11/12/2022] Open
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16
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Nguyen KQ, Rymar VV, Sadikot AF. Impaired TrkB Signaling Underlies Reduced BDNF-Mediated Trophic Support of Striatal Neurons in the R6/2 Mouse Model of Huntington's Disease. Front Cell Neurosci 2016; 10:37. [PMID: 27013968 PMCID: PMC4783409 DOI: 10.3389/fncel.2016.00037] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 02/01/2016] [Indexed: 11/13/2022] Open
Abstract
The principal projection neurons of the striatum are critically dependent on an afferent supply of brain derived neurotrophic factor (BDNF) for neurotrophic support. These neurons express TrkB, the cognate receptor for BDNF, which activates signaling pathways associated with neuronal survival and phenotypic maintenance. Impairment of the BDNF-TrkB pathway is suspected to underlie the early dysfunction and prominent degeneration of striatal neurons in Huntington disease (HD). Some studies in HD models indicate that BDNF supply is reduced, while others suggest that TrkB signaling is impaired earlier in disease progression. It remains important to determine whether a primary defect in TrkB signaling underlies reduced neurotrophic support and the early vulnerability of striatal neurons in HD. Using the transgenic R6/2 mouse model of HD we found that prior to striatal degeneration there are early deficits in striatal protein levels of activated phospho-TrkB and the downstream-regulated protein DARPP-32. In contrast, total-TrkB and BDNF protein levels remained normal. Primary neurons cultured from R6/2 striatum exhibited reduced survival in response to exogenous BDNF applications. Moreover, BDNF activation of phospho-TrkB and downstream signal transduction was attenuated in R6/2 striatal cultures. These results suggest that neurotrophic support of striatal neurons is attenuated early in disease progression due to defects in TrkB signal transduction in the R6/2 model of HD.
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Affiliation(s)
- Khanh Q Nguyen
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Vladimir V Rymar
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Abbas F Sadikot
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
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17
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Noda Y, Shimazawa M, Tanaka H, Tamura S, Inoue T, Tsuruma K, Hara H. VGF and striatal cell damage in in vitro and in vivo models of Huntington's disease. Pharmacol Res Perspect 2015; 3:e00140. [PMID: 26171223 PMCID: PMC4492756 DOI: 10.1002/prp2.140] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 03/04/2015] [Accepted: 03/10/2015] [Indexed: 11/11/2022] Open
Abstract
Huntington's disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements, and at present there is no effective treatment for HD. Therapeutic options for HD are limited to symptomatic treatment approaches and there is no cure for this devastating disease. Here, we examined whether SUN N8075, (2S)-1-(4-amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl)phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate, which exerts neuroprotective effects by antioxidant effects and induction of VGF nerve growth factor inducible (VGF), has beneficial effects in STHdh cells derived from striatum of knock-in HD mice and R6/2 HD mice. In an in vitro study, SUN N8075 inhibited the cell death caused by mutant huntingtin (mHtt) and upregulated the VGF mRNA level via the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, 30 amino acid of VGF C-terminal peptide, AQEE-30 inhibited the cell death and the aggregation of mHtt. In an in vivo study, SUN N8075 improved the survival and the clasping response in the R6/2 mice. Furthermore, SUN N8075 increased the number of surviving neurons in the striatum of the R6/2 mice. These findings suggest that SUN N8075 may be an effective candidate for HD treatments.
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Affiliation(s)
- Yasuhiro Noda
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Hirotaka Tanaka
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Shigeki Tamura
- Asubio Pharma Co., Ltd. 6-4-3, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Teruyoshi Inoue
- Asubio Pharma Co., Ltd. 6-4-3, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Kazuhiro Tsuruma
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
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18
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Gratuze M, Noël A, Julien C, Cisbani G, Milot-Rousseau P, Morin F, Dickler M, Goupil C, Bezeau F, Poitras I, Bissonnette S, Whittington RA, Hébert SS, Cicchetti F, Parker JA, Samadi P, Planel E. Tau hyperphosphorylation and deregulation of calcineurin in mouse models of Huntington's disease. Hum Mol Genet 2014; 24:86-99. [DOI: 10.1093/hmg/ddu456] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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19
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Xu Q, Huang S, Song M, Wang CE, Yan S, Liu X, Gaertig MA, Yu SP, Li H, Li S, Li XJ. Synaptic mutant huntingtin inhibits synapsin-1 phosphorylation and causes neurological symptoms. ACTA ACUST UNITED AC 2013; 202:1123-38. [PMID: 24081492 PMCID: PMC3787372 DOI: 10.1083/jcb.201303146] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Polyglutamine-expanded huntingtin specifically targeted to synapses binds to synapsin-1, inhibits its phosphorylation, and causes defects in neurotransmitter release and age-dependent defects in neurological function. Many genetic mouse models of Huntington’s disease (HD) have established that mutant huntingtin (htt) accumulates in various subcellular regions to affect a variety of cellular functions, but whether and how synaptic mutant htt directly mediates HD neuropathology remains to be determined. We generated transgenic mice that selectively express mutant htt in the presynaptic terminals. Although it was not overexpressed, synaptic mutant htt caused age-dependent neurological symptoms and early death in mice as well as defects in synaptic neurotransmitter release. Mass spectrometry analysis of synaptic fractions and immunoprecipitation of synapsin-1 from HD CAG150 knockin mouse brains revealed that mutant htt binds to synapsin-1, a protein whose phosphorylation is critical for neurotransmitter release. We found that polyglutamine-expanded exon1 htt binds to the C-terminal region of synapsin-1 to reduce synapsin-1 phosphorylation. Our findings point to a critical role for synaptic htt in the neurological symptoms of HD, providing a new therapeutic target.
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Affiliation(s)
- Qiaoqiao Xu
- Department of Histology and Anatomy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430032, China
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20
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Chan B, Cottrell JR, Li B, Larson KC, Ashford CJ, Levenson JM, Laeng P, Gerber DJ, Song J. Development of a high-throughput AlphaScreen assay for modulators of synapsin I phosphorylation in primary neurons. ACTA ACUST UNITED AC 2013; 19:205-14. [PMID: 24088370 DOI: 10.1177/1087057113505905] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alterations in synaptic transmission have been implicated in a number of psychiatric and neurological disorders. The discovery of small-molecule modulators of proteins that regulate neurotransmission represents a novel therapeutic strategy for these diseases. However, high-throughput screening (HTS) approaches in primary neurons have been limited by challenges in preparing and applying primary neuronal cultures under conditions required for generating sufficiently robust and sensitive HTS assays. Synapsin I is an abundant presynaptic protein that plays a critical role in neurotransmission through tethering synaptic vesicles to the actin cytoskeleton. It has several phosphorylation sites that regulate its modulation of synaptic vesicle trafficking and, therefore, the efficacy of synaptic transmission. Here, we describe the development of a rapid, sensitive, and homogeneous assay to detect phospho-synapsin I (pSYN1) in primary cortical neurons in 384-well plates using AlphaScreen technology. From results of a pilot screening campaign, we show that the assay can identify compounds that modulate synapsin I phosphorylation via multiple signaling pathways. The implementation of the AlphaScreen pSYN1 assay and future development of additional primary neuronal HTS assays provides an attractive approach for discovery of novel classes of therapeutic candidates for a variety of CNS disorders.
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Affiliation(s)
- Betty Chan
- 1Galenea Corporation, Wakefield, MA, USA
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21
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Fusco FR, Anzilotti S, Giampà C, Dato C, Laurenti D, Leuti A, Colucci D'Amato L, Perrone L, Bernardi G, Melone MA. Changes in the expression of extracellular regulated kinase (ERK 1/2) in the R6/2 mouse model of Huntington's disease after phosphodiesterase IV inhibition. Neurobiol Dis 2012; 46:225-33. [DOI: 10.1016/j.nbd.2012.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 01/09/2012] [Accepted: 01/21/2012] [Indexed: 11/29/2022] Open
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22
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Crittenden JR, Graybiel AM. Basal Ganglia disorders associated with imbalances in the striatal striosome and matrix compartments. Front Neuroanat 2011; 5:59. [PMID: 21941467 PMCID: PMC3171104 DOI: 10.3389/fnana.2011.00059] [Citation(s) in RCA: 300] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 08/18/2011] [Indexed: 11/24/2022] Open
Abstract
The striatum is composed principally of GABAergic, medium spiny striatal projection neurons (MSNs) that can be categorized based on their gene expression, electrophysiological profiles, and input–output circuits. Major subdivisions of MSN populations include (1) those in ventromedial and dorsolateral striatal regions, (2) those giving rise to the direct and indirect pathways, and (3) those that lie in the striosome and matrix compartments. The first two classificatory schemes have enabled advances in understanding of how basal ganglia circuits contribute to disease. However, despite the large number of molecules that are differentially expressed in the striosomes or the extra-striosomal matrix, and the evidence that these compartments have different input–output connections, our understanding of how this compartmentalization contributes to striatal function is still not clear. A broad view is that the matrix contains the direct and indirect pathway MSNs that form parts of sensorimotor and associative circuits, whereas striosomes contain MSNs that receive input from parts of limbic cortex and project directly or indirectly to the dopamine-containing neurons of the substantia nigra, pars compacta. Striosomes are widely distributed within the striatum and are thought to exert global, as well as local, influences on striatal processing by exchanging information with the surrounding matrix, including through interneurons that send processes into both compartments. It has been suggested that striosomes exert and maintain limbic control over behaviors driven by surrounding sensorimotor and associative parts of the striatal matrix. Consistent with this possibility, imbalances between striosome and matrix functions have been reported in relation to neurological disorders, including Huntington’s disease, L-DOPA-induced dyskinesias, dystonia, and drug addiction. Here, we consider how signaling imbalances between the striosomes and matrix might relate to symptomatology in these disorders.
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Affiliation(s)
- Jill R Crittenden
- Brain and Cognitive Sciences Department and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA
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Striatal-enriched protein tyrosine phosphatase expression and activity in Huntington's disease: a STEP in the resistance to excitotoxicity. J Neurosci 2011; 31:8150-62. [PMID: 21632937 DOI: 10.1523/jneurosci.3446-10.2011] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Striatal-enriched protein tyrosine phosphatase (STEP) is highly expressed in striatal projection neurons, the neuronal population most affected in Huntington's disease. Here, we examined STEP expression and phosphorylation, which regulates its activity, in N-terminal exon-1 and full-length mutant huntingtin mouse models. R6/1 mice displayed reduced STEP protein levels in the striatum and cortex, whereas its phosphorylation was increased in the striatum, cortex, and hippocampus. The early increase in striatal STEP phosphorylation levels correlated with a deregulation of the protein kinase A pathway, and decreased calcineurin activity at later stages further contributes to an enhancement of STEP phosphorylation and inactivation. Accordingly, we detected an accumulation of phosphorylated ERK2 and p38, two targets of STEP, in R6/1 mice striatum at advanced stages of the disease. Activation of STEP participates in excitotoxic-induced cell death. Because Huntington's disease mouse models develop resistance to excitotoxicity, we analyzed whether decreased STEP activity was involved in this process. After intrastriatal quinolinic acid (QUIN) injection, we detected higher phosphorylated STEP levels in R6/1 than in wild-type mice, suggesting that STEP inactivation could mediate neuroprotection in R6/1 striatum. In agreement, intrastriatal injection of TAT-STEP increased QUIN-induced cell death. R6/2, Tet/HD94, and Hdh(Q7/Q111) mice striatum also displayed decreased STEP protein and increased phosphorylation levels. In Tet/HD94 mice striatum, mutant huntingtin transgene shutdown reestablished STEP expression. In conclusion, the STEP pathway is severely downregulated in the presence of mutant huntingtin and may participate in compensatory mechanisms activated by striatal neurons that lead to resistance to excitotoxicity.
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Zhu S, Zhang Y, Bai G, Li H. Necrostatin-1 ameliorates symptoms in R6/2 transgenic mouse model of Huntington's disease. Cell Death Dis 2011; 2:e115. [PMID: 21359116 PMCID: PMC3043604 DOI: 10.1038/cddis.2010.94] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Seredenina T, Gokce O, Luthi-Carter R. Decreased striatal RGS2 expression is neuroprotective in Huntington's disease (HD) and exemplifies a compensatory aspect of HD-induced gene regulation. PLoS One 2011; 6:e22231. [PMID: 21779398 PMCID: PMC3136499 DOI: 10.1371/journal.pone.0022231] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 06/17/2011] [Indexed: 02/04/2023] Open
Abstract
Background The molecular phenotype of Huntington's disease (HD) is known to comprise highly reproducible changes in gene expression involving striatal signaling genes. Here we test whether individual changes in striatal gene expression are capable of mitigating HD-related neurotoxicity. Methodology/Principal Findings We used protein-encoding and shRNA-expressing lentiviral vectors to evaluate the effects of RGS2, RASD2, STEP and NNAT downregulation in HD. Of these four genes, only RGS2 and RASD2 modified mutant htt fragment toxicity in cultured rat primary striatal neurons. In both cases, disease modulation was in the opposite of the predicted direction: whereas decreased expression of RGS2 and RASD2 was associated with the HD condition, restoring expression enhanced degeneration of striatal cells. Conversely, silencing of RGS2 or RASD2 enhanced disease-related changes in gene expression and resulted in significant neuroprotection. These results indicate that RGS2 and RASD2 downregulation comprises a compensatory response that allows neurons to better tolerate huntingtin toxicity. Assessment of the possible mechanism of RGS2-mediated neuroprotection showed that RGS2 downregulation enhanced ERK activation. These results establish a novel link between the inhibition of RGS2 and neuroprotective modulation of ERK activity. Conclusions Our findings both identify RGS2 downregulation as a novel compensatory response in HD neurons and suggest that RGS2 inhibition might be considered as an innovative target for neuroprotective drug development.
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Affiliation(s)
- Tamara Seredenina
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ozgun Gokce
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ruth Luthi-Carter
- Laboratory of Functional Neurogenomics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- * E-mail:
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Rosenstock TR, Bertoncini CRA, Teles AV, Hirata H, Fernandes MJS, Smaili SS. Glutamate-induced alterations in Ca2+ signaling are modulated by mitochondrial Ca2+ handling capacity in brain slices of R6/1 transgenic mice. Eur J Neurosci 2011; 32:60-70. [PMID: 20608968 DOI: 10.1111/j.1460-9568.2010.07268.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expansion of CAGs repeats and characterized by alterations in mitochondrial functions. Although changes in Ca(2+) handling have been suggested, the mechanisms involved are not completely understood. The aim of this study was to investigate the possible alterations in Ca(2+) handling capacity and the relationship with mitochondrial dysfunction evaluated by NAD(P)H fluorescence, reactive oxygen species levels, mitochondrial membrane potential (DeltaPsi(m)) measurements and respiration in whole brain slices from R6/1 mice of different ages, evaluated in situ by real-time real-space microscopy. We show that the cortex and striatum of the 9-month-old R6/1 transgenic mice present a significant sustained increase in cytosolic Ca(2+) induced by glutamate (Glu). This difference in Glu response was partially reduced in R6/1 when in the absence of extracellular Ca(2+), indicating that N-methyl-D-aspartate receptors participation in this response is more important in transgenic mice. In addition, Glu also lead to a decrease in NAD(P)H fluorescence, a loss in DeltaPsi(m) and a further increase in respiration, which may have evoked a decrease in mitochondrial Ca(2+) Ca(2+)(m) uptake capacity. Taken together, these results show that alterations in Ca(2+) homeostasis in transgenic mice are associated with a decrease in Ca(2+)(m) uptake mechanism with a diminished Ca(2+) handling ability that ultimately causes dysfunctions and worsening of the neurodegenerative and the disease processes.
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Affiliation(s)
- T R Rosenstock
- Departamento de Farmacologia, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
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Han I, You Y, Kordower JH, Brady ST, Morfini GA. Differential vulnerability of neurons in Huntington's disease: the role of cell type-specific features. J Neurochem 2010; 113:1073-91. [PMID: 20236390 DOI: 10.1111/j.1471-4159.2010.06672.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abnormal expansion of a polyglutamine tract in huntingtin (Htt) protein results in Huntington's disease (HD), an autosomal dominant neurodegenerative disorder involving progressive loss of motor and cognitive function. Contrasting with the ubiquitous tissue expression of polyglutamine-expanded Htt, HD pathology is characterized by the increased vulnerability of specific neuronal populations within the striatum and the cerebral cortex. Morphological, biochemical, and functional characteristics of neurons affected in HD that might render these cells more vulnerable to the toxic effects of polyglutamine-Htt are covered in this review. The differential vulnerability of neurons observed in HD is discussed in the context of various major pathogenic mechanisms proposed to date, and in line with evidence showing a 'dying-back' pattern of degeneration in affected neuronal populations.
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Affiliation(s)
- Ina Han
- Department of Anatomy and Cell Biology. University of Illinois at Chicago, Chicago, Illinois 60612, USA
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28
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Crittenden JR, Dunn DE, Merali FI, Woodman B, Yim M, Borkowska AE, Frosch MP, Bates GP, Housman DE, Lo DC, Graybiel AM. CalDAG-GEFI down-regulation in the striatum as a neuroprotective change in Huntington's disease. Hum Mol Genet 2010; 19:1756-65. [PMID: 20147317 DOI: 10.1093/hmg/ddq055] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Huntingtin protein (Htt) is ubiquitously expressed, yet Huntington's disease (HD), a fatal neurologic disorder produced by expansion of an Htt polyglutamine tract, is characterized by neurodegeneration that occurs primarily in the striatum and cerebral cortex. Such discrepancies between sites of expression and pathology occur in multiple neurodegenerative disorders associated with expanded polyglutamine tracts. One possible reason is that disease-modifying factors are tissue-specific. Here, we show that the striatum-enriched protein, CalDAG-GEFI, is severely down-regulated in the striatum of mouse HD models and is down-regulated in HD individuals. In the R6/2 transgenic mouse model of HD, striatal neurons with the largest aggregates of mutant Htt have the lowest levels of CalDAG-GEFI. In a brain-slice explant model of HD, knock-down of CalDAG-GEFI expression rescues striatal neurons from pathology induced by transfection of polyglutamine-expanded Htt exon 1. These findings suggest that the striking down-regulation of CalDAG-GEFI in HD could be a protective mechanism that mitigates Htt-induced degeneration.
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Affiliation(s)
- Jill R Crittenden
- McGovern Institute for Brain Research, MIT, 43 Vassar Street, Building 46-6133, Cambridge, MA, USA
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29
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Morfini GA, Burns M, Binder LI, Kanaan NM, LaPointe N, Bosco DA, Brown RH, Brown H, Tiwari A, Hayward L, Edgar J, Nave KA, Garberrn J, Atagi Y, Song Y, Pigino G, Brady ST. Axonal transport defects in neurodegenerative diseases. J Neurosci 2009; 29:12776-86. [PMID: 19828789 PMCID: PMC2801051 DOI: 10.1523/jneurosci.3463-09.2009] [Citation(s) in RCA: 335] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 08/04/2009] [Indexed: 12/26/2022] Open
Abstract
Adult-onset neurodegenerative diseases (AONDs) comprise a heterogeneous group of neurological disorders characterized by a progressive, age-dependent decline in neuronal function and loss of selected neuronal populations. Alterations in synaptic function and axonal connectivity represent early and critical pathogenic events in AONDs, but molecular mechanisms underlying these defects remain elusive. The large size and complex subcellular architecture of neurons render them uniquely vulnerable to alterations in axonal transport (AT). Accordingly, deficits in AT have been documented in most AONDs, suggesting a common defect acquired through different pathogenic pathways. These observations suggest that many AONDs can be categorized as dysferopathies, diseases in which alterations in AT represent a critical component in pathogenesis. Topics here address various molecular mechanisms underlying alterations in AT in several AONDs. Illumination of such mechanisms provides a framework for the development of novel therapeutic strategies aimed to prevent axonal and synaptic dysfunction in several major AONDs.
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Affiliation(s)
- Gerardo A Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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30
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Alterations in cortical excitation and inhibition in genetic mouse models of Huntington's disease. J Neurosci 2009; 29:10371-86. [PMID: 19692612 DOI: 10.1523/jneurosci.1592-09.2009] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Previously, we identified progressive alterations in spontaneous EPSCs and IPSCs in the striatum of the R6/2 mouse model of Huntington's disease (HD). Medium-sized spiny neurons from these mice displayed a lower frequency of EPSCs, and a population of cells exhibited an increased frequency of IPSCs beginning at approximately 40 d, a time point when the overt behavioral phenotype begins. The cortex provides the major excitatory drive to the striatum and is affected during disease progression. We examined spontaneous EPSCs and IPSCs of somatosensory cortical pyramidal neurons in layers II/III in slices from three different mouse models of HD: the R6/2, the YAC128, and the CAG140 knock-in. Results revealed that spontaneous EPSCs occurred at a higher frequency, and evoked EPSCs were larger in behaviorally phenotypic mice whereas spontaneous IPSCs were initially increased in frequency in all models and subsequently decreased in R6/2 mice after they displayed the typical R6/2 overt behavioral phenotype. Changes in miniature IPSCs and evoked IPSC paired-pulse ratios suggested altered probability of GABA release. Also, in R6/2 mice, blockade of GABA(A) receptors induced complex discharges in slices and seizures in vivo at all ages. In conclusion, altered excitatory and inhibitory inputs to pyramidal neurons in the cortex in HD appear to be a prevailing deficit throughout the development of the disease. Furthermore, the differences between synaptic phenotypes in cortex and striatum are important for the development of future therapeutic approaches, which may need to be targeted early in the development of the phenotype.
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31
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Xifró X, Giralt A, Saavedra A, García-Martínez JM, Díaz-Hernández M, Lucas JJ, Alberch J, Pérez-Navarro E. Reduced calcineurin protein levels and activity in exon-1 mouse models of Huntington's disease: role in excitotoxicity. Neurobiol Dis 2009; 36:461-9. [PMID: 19733666 DOI: 10.1016/j.nbd.2009.08.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 08/03/2009] [Accepted: 08/28/2009] [Indexed: 11/28/2022] Open
Abstract
Calcineurin is a serine/threonine phosphatase involved in the regulation of glutamate receptors signaling. Here, we analyzed whether the regulation of calcineurin protein levels and activity modulates the susceptibility of striatal neurons to excitotoxicity in R6/1 and R6/1:BDNF+/- mouse models of Huntington's disease. We show that calcineurin inhibition in wild-type mice drastically reduced quinolinic acid-induced striatal cell death. Moreover, calcineurin A and B were differentially regulated during disease progression with a specific reduction of calcineurin A protein levels and calcineurin activity at the onset of the disease in R6/1:BDNF+/- mice. Analysis of the conditional mouse model Tet/HD94 showed that mutant huntingtin specifically controls calcineurin A protein levels. Finally, calcineurin activation induced by intrastriatal quinolinic acid injection in R6/1 mouse was lower than in wild-type mice. Therefore, reduction of calcineurin activity by alteration of calcineurin A expression participates in the pathophysiology of Huntington's disease and contributes to the excitotoxic resistance observed in exon-1 mouse models.
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Affiliation(s)
- Xavier Xifró
- Departament de Biologia Cel.lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, IDIBAPS, Casanova 143, E-08036 Barcelona, Spain
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32
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Polyglutamine gene function and dysfunction in the ageing brain. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1779:507-21. [PMID: 18582603 DOI: 10.1016/j.bbagrm.2008.05.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 04/29/2008] [Accepted: 05/30/2008] [Indexed: 11/23/2022]
Abstract
The coordinated regulation of gene expression and protein interactions determines how mammalian nervous systems develop and retain function and plasticity over extended periods of time such as a human life span. By studying mutations that occur in a group of genes associated with chronic neurodegeneration, the polyglutamine (polyQ) disorders, it has emerged that CAG/glutamine stretches play important roles in transcriptional regulation and protein-protein interactions. However, it is still unclear what the many structural and functional roles of CAG and other low-complexity sequences in eukaryotic genomes are, despite being the most commonly shared peptide fragments in such proteomes. In this review we examine the function of genes responsible for at least 10 polyglutamine disorders in relation to the nervous system and how expansion mutations lead to neuronal dysfunction, by particularly focusing on Huntington's disease (HD). We argue that the molecular and cellular pathways that turn out to be dysfunctional during such diseases, as a consequence of a CAG expansion, are also involved in the ageing of the central nervous system. These are pathways that control protein degradation systems (including molecular chaperones), axonal transport, redox-homeostasis and bioenergetics. CAG expansion mutations confer novel properties on proteins that lead to a slow-progressing neuronal pathology and cell death similar to that found in other age-related conditions such as Alzheimer's and Parkinson's diseases.
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33
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Apostol BL, Simmons DA, Zuccato C, Illes K, Pallos J, Casale M, Conforti P, Ramos C, Roarke M, Kathuria S, Cattaneo E, Marsh JL, Thompson LM. CEP-1347 reduces mutant huntingtin-associated neurotoxicity and restores BDNF levels in R6/2 mice. Mol Cell Neurosci 2008; 39:8-20. [PMID: 18602275 DOI: 10.1016/j.mcn.2008.04.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 03/27/2008] [Accepted: 04/11/2008] [Indexed: 01/09/2023] Open
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the protein Huntingtin (Htt). We previously reported that mutant Htt expression activates the ERK1/2 and JNK pathways [Apostol, B.L., Illes, K., Pallos, J., Bodai, L., Wu, J., Strand, A., Schweitzer, E.S., Olson, J.M., Kazantsev, A., Marsh, J.L., Thompson, L.M., 2006. Mutant huntingtin alters MAPK signaling pathways in PC12 and striatal cells: ERK1/2 protects against mutant huntingtin-associated toxicity. Hum. Mol. Genet. 15, 273-285]. Chemical and genetic modulation of these pathways promotes cell survival and death, respectively. Here we test the ability of two closely related compounds, CEP-11004 and CEP-1347, which inhibit Mixed Lineage Kinases (MLKs) and are neuroprotective, to suppress mutant Htt-mediated pathogenesis in multiple model systems. CEP-11004/CEP-1347 treatment significantly decreased toxicity in mutant Htt-expressing cells that evoke a strong JNK response. However, suppression of cellular dysfunction in cell lines that exhibit only mild Htt-associated toxicity and little JNK activation was associated with activation of ERK1/2. These compounds also reduced neurotoxicity in immortalized striatal neurons from mutant knock-in mice and Drosophila expressing a mutant Htt fragment. Finally, CEP-1347 improved motor performance in R6/2 mice and restored expression of BDNF, a critical neurotrophic factor that is reduced in HD. These studies suggest a novel therapeutic approach for a currently untreatable neurodegenerative disease, HD, via CEP-1347 up-regulation of BDNF.
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Affiliation(s)
- Barbara L Apostol
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697, USA
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34
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Romero E, Cha GH, Verstreken P, Ly CV, Hughes RE, Bellen HJ, Botas J. Suppression of neurodegeneration and increased neurotransmission caused by expanded full-length huntingtin accumulating in the cytoplasm. Neuron 2008; 57:27-40. [PMID: 18184562 DOI: 10.1016/j.neuron.2007.11.025] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 06/21/2007] [Accepted: 11/06/2007] [Indexed: 11/26/2022]
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by expansion of a translated CAG repeat in the N terminus of the huntingtin (htt) protein. Here we describe the generation and characterization of a full-length HD Drosophila model to reveal a previously unknown disease mechanism that occurs early in the course of pathogenesis, before expanded htt is imported into the nucleus in detectable amounts. We find that expanded full-length htt (128Qhtt(FL)) leads to behavioral, neurodegenerative, and electrophysiological phenotypes. These phenotypes are caused by a Ca2+-dependent increase in neurotransmitter release efficiency in 128Qhtt(FL) animals. Partial loss of function in synaptic transmission (syntaxin, Snap, Rop) and voltage-gated Ca2+ channel genes suppresses both the electrophysiological and the neurodegenerative phenotypes. Thus, our data indicate that increased neurotransmission is at the root of neuronal degeneration caused by expanded full-length htt during early stages of pathogenesis.
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Affiliation(s)
- Eliana Romero
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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35
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Xifró X, García-Martínez JM, Del Toro D, Alberch J, Pérez-Navarro E. Calcineurin is involved in the early activation of NMDA-mediated cell death in mutant huntingtin knock-in striatal cells. J Neurochem 2008; 105:1596-612. [PMID: 18221365 DOI: 10.1111/j.1471-4159.2008.05252.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Excitotoxicity has been proposed as one of the mechanisms involved in the specific loss of striatal neurons that occurs in Huntington's disease. Here, we studied the role of calcineurin in the vulnerability of striatal neurons expressing mutant huntingtin to excitotoxicity. To this end, we induced excitotoxicity by adding NMDA to a striatal precursor cell line expressing full-length wild-type (STHdh(Q7/Q7)) or mutant (STHdh(Q111/Q111)) huntingtin. We observed that cell death appeared earlier in STHdh(Q111/Q111) cells than in STHdh(Q7/Q7) cells. Interestingly, these former cells expressed higher levels of calcineurin A that resulted in a greater increase of its activity after NMDA receptor stimulation. Moreover, transfection of full-length mutant huntingtin in different striatal-derived cells (STHdh(Q7/Q7), M213 and primary cultures) increased calcineurin A protein levels. To determine whether high levels of calcineurin A might account for the earlier activation of cell death in mutant huntingtin knock-in cells, wild-type cells were transfected with calcineurin A. Calcineurin A-transfected STHdh(Q7/Q7) cells displayed a significant increase in cell death compared with that recorded in green fluorescent protein-transfected cells after NMDA treatment. Notably, addition of the calcineurin inhibitor FK-506 produced a more robust reduction in cell death in mutant huntingtin knock-in cells than it did in wild-type cells. These results suggest that high levels of calcineurin A could account for the increased vulnerability of striatal cells expressing mutant huntingtin to excitotoxicity.
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Affiliation(s)
- Xavier Xifró
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
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36
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Cavalli A, Bolognesi ML, Minarini A, Rosini M, Tumiatti V, Recanatini M, Melchiorre C. Multi-target-directed ligands to combat neurodegenerative diseases. J Med Chem 2008; 51:347-72. [PMID: 18181565 DOI: 10.1021/jm7009364] [Citation(s) in RCA: 823] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Andrea Cavalli
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy.
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37
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Cortical and brainstem LTP-like plasticity in Huntington's disease. Brain Res Bull 2008; 75:107-14. [DOI: 10.1016/j.brainresbull.2007.07.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 07/27/2007] [Accepted: 07/27/2007] [Indexed: 11/24/2022]
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38
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Roze E, Bettuing S, Deyts C, Marcon E, Brami‐Cherrier K, Pagès C, Humbert S, Mérienne K, Caboche J. Mitogen‐ and stress‐activated protein kinase‐1 deficiency is involved in expanded‐huntingtin‐induced transcriptional dysregulation and striatal death. FASEB J 2007; 22:1083-93. [DOI: 10.1096/fj.07-9814] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Emmanuel Roze
- Université Pierre et Marie Curie‐Paris 6, CNRS, UMR 7102ParisFrance
- Service de NeurologieHôpital Saint‐AntoineAssitance Publique‐Hôpitaux de ParisParisFrance
| | | | - Carole Deyts
- Université Pierre et Marie Curie‐Paris 6, CNRS, UMR 7102ParisFrance
| | - Estelle Marcon
- Université Pierre et Marie Curie‐Paris 6, CNRS, UMR 7102ParisFrance
| | | | - Christiane Pagès
- Université Pierre et Marie Curie‐Paris 6, CNRS, UMR 7102ParisFrance
| | | | - Karine Mérienne
- Institut de Génétique et de Biologie Moléculaire et CellulaireDépartement de pathologie moléculaire; INSERM, U596; CNRS, UMR 7104IllkirchFrance
| | - Jocelyne Caboche
- Université Pierre et Marie Curie‐Paris 6, CNRS, UMR 7102ParisFrance
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39
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Cepeda C, Wu N, André VM, Cummings DM, Levine MS. The corticostriatal pathway in Huntington's disease. Prog Neurobiol 2006; 81:253-71. [PMID: 17169479 PMCID: PMC1913635 DOI: 10.1016/j.pneurobio.2006.11.001] [Citation(s) in RCA: 233] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 10/08/2006] [Accepted: 11/03/2006] [Indexed: 11/21/2022]
Abstract
The corticostriatal pathway provides most of the excitatory glutamatergic input into the striatum and it plays an important role in the development of the phenotype of Huntington's disease (HD). This review summarizes results obtained from genetic HD mouse models concerning various alterations in this pathway. Evidence indicates that dysfunctions of striatal circuits and cortical neurons that make up the corticostriatal pathway occur during the development of the HD phenotype, well before there is significant neuronal cell loss. Morphological changes in the striatum are probably primed initially by alterations in the intrinsic functional properties of striatal medium-sized spiny neurons. Some of these alterations, including increased sensitivity of N-methyl-D-aspartate receptors in subpopulations of neurons, might be constitutively present but ultimately require abnormalities in the corticostriatal inputs for the phenotype to be expressed. Dysfunctions of the corticostriatal pathway are complex and there are multiple changes as demonstrated by significant age-related transient and more chronic interactions with the disease state. There also is growing evidence for changes in cortical microcircuits that interact to induce dysfunctions of the corticostriatal pathway. The conclusions of this review emphasize, first, the general role of neuronal circuits in the expression of the HD phenotype and, second, that both cortical and striatal circuits must be included in attempts to establish a framework for more rational therapeutic strategies in HD. Finally, as changes in cortical and striatal circuitry are complex and in some cases biphasic, therapeutic interventions should be regionally specific and take into account the temporal progression of the phenotype.
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Affiliation(s)
- Carlos Cepeda
- Mental Retardation Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
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40
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Cummings DM, Milnerwood AJ, Dallérac GM, Waights V, Brown JY, Vatsavayai SC, Hirst MC, Murphy KPSJ. Aberrant cortical synaptic plasticity and dopaminergic dysfunction in a mouse model of huntington's disease. Hum Mol Genet 2006; 15:2856-68. [PMID: 16905556 DOI: 10.1093/hmg/ddl224] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Predictive genetic testing for Huntington's disease (HD) has revealed early cognitive deficits in asymptomatic gene carriers, such as altered working memory, executive function and impaired recognition memory. The perirhinal cortex processes aspects of recognition memory and the underlying mechanism is believed to be long-term depression (LTD) of excitatory neurotransmission, the converse of long-term potentiation (LTP). We have used the R6/1 mouse model of HD to assess synaptic plasticity in the perirhinal cortex. We report here a progressive derailment of both LTD and short-term plasticity at perirhinal synapses. Layer II/III neurones gradually lose their ability to support LTD, show early nuclear localization of mutant huntingtin and display a progressive loss of membrane integrity (depolarization and loss of cell capacitance) accompanied by a reduction in the expression of D1 and D2 dopamine receptors visualized in layer I of the perirhinal cortex. Importantly, abnormalities in both short-term and long-term plasticity can be reversed by the introduction of a D2 dopamine receptor agonist (Quinpirole), suggesting that alterations in dopaminergic signalling may underlie early cognitive dysfunction in HD.
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Affiliation(s)
- Damian M Cummings
- Huntington's Disease Research Forum, Department of Biological Sciences, Open University, Milton Keynes, UK
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41
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Crocker SF, Costain WJ, Robertson HA. DNA microarray analysis of striatal gene expression in symptomatic transgenic Huntington's mice (R6/2) reveals neuroinflammation and insulin associations. Brain Res 2006; 1088:176-86. [PMID: 16626669 DOI: 10.1016/j.brainres.2006.02.102] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 02/03/2006] [Accepted: 02/26/2006] [Indexed: 11/21/2022]
Abstract
Huntington's disease (HD) is an inherited, progressive neurodegenerative disorder caused by CAG repeat expansion in the gene that codes for the protein huntingtin. The underlying neuropathological events leading to the selectivity of striatal neuronal loss are unknown. However, the huntingtin mutation interferes at several levels of normal cell function. The complexity of this disease makes microarray analysis an appealing technique to begin the identification of common pathways that may contribute to the pathology. In this study, striatal tissue was extracted for gene expression profiling from wild-type and symptomatic transgenic Huntington mice (R6/2) expressing part of the human Huntington's disease gene. We interrogated a 15 K high-density mouse EST array not previously used for HD and identified 170 significantly differentially expressed ESTs in symptomatic R6/2 mice. Of the 80 genes with known function, 9 genes had previously been identified as altered in HD. 71 known genes were associated with HD for the first time. The data obtained from this study confirm and extend previous observations using DNA microarray techniques on genetic models for HD, revealing novel changes in expression in a number of genes not previously associated with HD. Further bioinformatic analysis, using software to construct biological association maps, focused attention on proteins such as insulin and TH1-mediated cytokines, suggesting that they may be important regulators of affected genes. These results may provide insight into the regulation and interaction of genes that contribute to adaptive and pathological processes involved in HD.
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Affiliation(s)
- Susan F Crocker
- Brain Repair Centre, Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
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42
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Brooks SP, Betteridge H, Trueman RC, Jones L, Dunnett SB. Selective extra-dimensional set shifting deficit in a knock-in mouse model of Huntington's disease. Brain Res Bull 2006; 69:452-7. [PMID: 16624677 DOI: 10.1016/j.brainresbull.2006.02.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 02/17/2006] [Accepted: 02/19/2006] [Indexed: 11/17/2022]
Abstract
People with early-stage Huntington's disease have been found to have a specific deficit in performing an extra-dimensional shift. To date no evidence of this deficit has been identified in transgenic or knock-in rodent models of the disease. The aim of the present paper then, was to test whether homozygous knock-in mice derived from the Hdh(CAG(150)) mouse line were impaired in any of five 2-choice discrimination tasks (simple, compound, compound reversal, intra-dimensional shift and extra-dimensional shift), and whether these mice were impaired at recalling these tasks on the following day. On the extra-dimensional shift task the Hdh(CAG(150)) homozygous mice required a greater number of trials to reach criteria than mice and the percentage of correct choices within the trials was also significantly reduced compared with the animals. For the recall tasks, a deficit for recalling the compound reversal test was found in the Hdh(CAG(150)) homozygous mice for both number of trials required to reach criteria and percentage of correct choices within the trials. Recall for the intra-dimensional shift task was also impaired in these animals when measured by the percentage of correct choices. Our results demonstrate a pronounced deficit in the Hdh(CAG(150)) mice not only on extra-dimensional shift performance in agreement with human studies, but also on recall tasks for both the compound reversal and the intra-dimensional shift tasks.
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Affiliation(s)
- S P Brooks
- Cardiff University, Schools of Biological Sciences, Museum Avenue, PO Box 911, Cardiff CF10 3US, Wales, UK.
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43
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Johnson MA, Rajan V, Miller CE, Wightman RM. Dopamine release is severely compromised in the R6/2 mouse model of Huntington's disease. J Neurochem 2006; 97:737-46. [PMID: 16573654 DOI: 10.1111/j.1471-4159.2006.03762.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, alterations in dopamine signaling have been implicated in Huntington's disease. In this work, dopamine release and uptake was measured in striatal slices from the R6/2 transgenic mouse model of Huntington's disease using fast-scan cyclic voltammetry at carbon-fiber microelectrodes. Dopamine release in brain slices from 6-week-old R6/2 mice is substantially reduced (53% of wild type), while dopamine uptake is unaffected. In agreement with this, R6/2 mice injected with the dopamine uptake inhibitor cocaine exhibited a blunted motor activity response (54% of wild type). At 10 weeks of age, an even more dramatic motor activity decrease in response to cocaine injection (21% of wild type) was observed. Moreover, the pre-drug activity of 10-week-old R6/2 mice was significantly reduced (by 37%) compared with 6-week-old R6/2 mice. Striatal dopamine release decreased with age, indicating that progressive alterations in dopaminergic pathways may affect motor activity. The inhibition constants of cocaine and methamphetamine (METH) determined in brain slices differed little between genotype or age group, suggesting that the decreased responses to cocaine and METH arise from compromised dopamine release rather than differences in uptake or drug action. Collectively, these data demonstrate (i) a reduction in the ability of dopamine terminals to release dopamine and (ii) the importance of this attenuation of release on the motor symptoms of Huntington's disease.
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Affiliation(s)
- Michael A Johnson
- Department of Chemistry, The University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA
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44
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Li JY, Popovic N, Brundin P. The use of the R6 transgenic mouse models of Huntington's disease in attempts to develop novel therapeutic strategies. NeuroRx 2006; 2:447-64. [PMID: 16389308 PMCID: PMC1144488 DOI: 10.1602/neurorx.2.3.447] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Huntington's disease (HD) is a genetic neurodegenerative disorder. Since identification of the disease-causing gene in 1993, a number of genetically modified animal models of HD have been generated. The first transgenic mouse models, R6/1 and R6/2 lines, were established 8 years ago. The R6/2 mice have been the best characterized and the most widely used model to study pathogenesis of HD and therapeutic interventions. In the present review, we especially focus on the characteristics of R6 transgenic mouse models and, in greater detail, describe the different therapeutic strategies that have been tested in these mice. We also, at the end, critically assess the relevance of the HD mouse models compared with the human disease and discuss how they can be best used in the future.
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Affiliation(s)
- Jia Yi Li
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund, Sweden.
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Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder that generally begins in middle age with abnormalities of movement, cognition, personality, and mood. Neuronal loss is most marked among the medium-sized projection neurons of the dorsal striatum. HD is an autosomal dominant genetic disorder caused by a CAG expansion in exon 1 of the HD gene, encoding an expanded polyglutamine (polyQ) tract near the N-terminus of the protein huntingtin. Despite identification of the gene mutation more than a decade ago, the normal function of this ubiquitously expressed protein is still under investigation and the mechanisms underlying selective neurodegeneration in HD remain poorly understood. Detailed postmortem analyses of brains of HD patients have provided important clues, and HD transgenic and knock-in mouse models have facilitated investigations into potential pathogenic mechanisms. Subcellular fractionation and immunolocalization studies suggest a role for huntingtin in organelle transport, protein trafficking, and regulation of energy metabolism. Consistent with this, evidence from vertebrate and invertebrate models of HD indicates that expression of the polyQ-expanded form of huntingtin results in early impairment of axonal transport and mitochondrial function. As well, alteration in activity of the N-methyl-d-aspartate (NMDA) type glutamate receptor, which has been implicated as a main mediator of excitotoxic neuronal death, especially in the striatum, is an early effect of mutant huntingtin. Proteolysis and nuclear localization of huntingtin also occur relatively early, while formation of ubiquitinated aggregates of huntingtin and transcriptional dysregulation occur as late effects of the gene mutation. Although each of these processes may contribute to neuronal loss in HD, here we review the data to support a strong role for NMDA receptor (NMDAR)-mediated excitotoxicity and mitochondrial dysfunction in conferring selective neuronal vulnerability in HD.
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Affiliation(s)
- Catherine M Cowan
- Department of Psychiatry, Division of Neuroscience, Brain Research Centre University of British Columbia, Vancouver, British Columbia V6T 1Z3
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Apostol BL, Illes K, Pallos J, Bodai L, Wu J, Strand A, Schweitzer ES, Olson JM, Kazantsev A, Marsh JL, Thompson LM. Mutant huntingtin alters MAPK signaling pathways in PC12 and striatal cells: ERK1/2 protects against mutant huntingtin-associated toxicity. Hum Mol Genet 2005; 15:273-85. [PMID: 16330479 DOI: 10.1093/hmg/ddi443] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine (polyQ) tract within the huntingtin protein (Htt). Identifying the pathways that are altered in response to the mutant protein is crucial for understanding the cellular processes impacted by the disease as well as for the rational development of effective pharmacological interventions. Here, expression profiling of a cellular HD model identifies genes that implicate altered mitogen-activated protein kinase (MAPK) signaling. Targeted biochemical studies and pharmacological modulation of these MAPK pathways suggest that mutant Htt affects signaling at upstream points such that both ERK and JNK are activated. Modulation of the ERK pathway suggests that this pathway is associated with cell survival, whereas inhibition of JNK was found to effectively suppress pathogenesis. These studies suggest that pharmacological intervention in MAPK pathways, particularly at the level of ERK activation, may be an appropriate approach to HD therapy.
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Affiliation(s)
- Barbara L Apostol
- Department of Psychiatry and Human Behavior, University of California, Irvine, 92697, USA
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Smith R, Petersén A, Bates GP, Brundin P, Li JY. Depletion of rabphilin 3A in a transgenic mouse model (R6/1) of Huntington's disease, a possible culprit in synaptic dysfunction. Neurobiol Dis 2005; 20:673-84. [PMID: 15967669 DOI: 10.1016/j.nbd.2005.05.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Revised: 04/08/2005] [Accepted: 05/02/2005] [Indexed: 01/15/2023] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by progressive psychiatric, cognitive, and motor disturbances. We studied the expression of synaptic vesicle proteins in the R6/1 transgenic mouse model of HD. We observed that the levels of rabphilin 3A, a protein involved in exocytosis, is substantially decreased in synapses of most brain regions in R6/1 mice. The appearance of the reduction coincides with the onset of motor deficits and behavioral disturbances. Double immunohistochemistry did not show colocalization between rabphilin 3A and huntingtin aggregates in the HD mice. Using in situ hybridization, we demonstrated that rabphilin 3A mRNA expression was substantially reduced in the R6/1 mouse cortex compared to wild-type mice. Our results indicate that a decrease in mRNA levels underlie the depletion of protein levels of rabphilin 3A, and we suggest that this reduction may be involved in causing impaired synaptic transmission in R6/1 mice.
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Affiliation(s)
- Ruben Smith
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC A10, 221 84 Lund, Sweden
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Sun Z, Wang HB, Deng YP, Lei WL, Xie JP, Meade CA, Del Mar N, Goldowitz D, Reiner A. Increased calbindin-D28k immunoreactivity in striatal projection neurons of R6/2 Huntington's disease transgenic mice. Neurobiol Dis 2005; 20:907-17. [PMID: 15990326 DOI: 10.1016/j.nbd.2005.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 05/17/2005] [Accepted: 05/25/2005] [Indexed: 10/25/2022] Open
Abstract
Striatal degeneration in Huntington's disease (HD) is associated with increases in perikaryal calbindin immunolabeling in yet-surviving striatal projection neurons. Since similar increases have also been observed in surviving striatal projection neurons after intrastriatal injection of the excitotoxin quinolinic acid, the increased calbindin in HD striatum has been interpreted to suggest an excitotoxic process in HD. We used immunolabeling to assess if calbindin is elevated in striatal projection neurons of R6/2 HD transgenic mice. These mice bear exon 1 of the human huntingtin gene with 144 CAG repeats and show some of the neuropathological signs (e.g., neuronal intranuclear inclusions) and clinical traits (e.g., wasting prior to early death) of HD. We found an increased frequency of calbindin-immunoreactive neuronal perikarya in the striatum of 6- and 12-week-old R6/2 mice compared to wild-type controls. This increase was most notable in the normally calbindin-poor dorsolateral striatum. We found no significant changes in the total area of striatum occupied by the calbindin-negative striosomes and no consistent changes in striatal calbindin mRNA. The increase in calbindin in R6/2 striatal neurons was thus limited to the matrix compartment, and it may be triggered by increased Ca2+ entry due to the demonstrated heightened NMDA sensitivity of these neurons. The data further support the similarity of R6/2 mice to HD, and are consistent with the occurrence of an excitotoxic process in striatum in both.
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Affiliation(s)
- Z Sun
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Avenue, Memphis, TN 38163, USA
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Levine MS, Cepeda C, Hickey MA, Fleming SM, Chesselet MF. Genetic mouse models of Huntington's and Parkinson's diseases: illuminating but imperfect. Trends Neurosci 2004; 27:691-7. [PMID: 15474170 DOI: 10.1016/j.tins.2004.08.008] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Genetic mouse models based on identification of genes that cause Huntington's and Parkinson's diseases have revolutionized understanding of the mechanistic pathophysiological progression of these disorders. These models allow the earliest manifestations of the diseases to be identified, and they display behavioral, neuropathological and electrophysiological deficits that can be followed over time in mechanistic and drug studies. An intriguing feature is that they do not reproduce the relatively selective and massive cell loss characterizing the human diseases. There is more information on Huntington's disease models because the disorder involves a single gene that was identified over ten years ago; genetic mutations causing Parkinson's disease are rare and were discovered more recently, and models of the disease have been generated only within the past few years.
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Affiliation(s)
- Michael S Levine
- Mental Retardation Research Center, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Freeman W, Morton AJ. Regional and progressive changes in brain expression of complexin II in a mouse transgenic for the Huntington's disease mutation. Brain Res Bull 2004; 63:45-55. [PMID: 15121238 DOI: 10.1016/j.brainresbull.2003.12.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 12/12/2003] [Indexed: 11/16/2022]
Abstract
Changes in mRNA expression of soluble NSF-attachment protein receptors (SNAREs) and SNARE-associated proteins have been shown to occur in a number of disorders such as schizophrenia, Alzheimer's disease and Parkinson's disease. We have shown previously that there is a decrease in protein levels of the SNARE-associated protein, complexin II (CPLXII) in Huntington's disease brain and in the R6/2 mouse model of Huntington's disease. In the current study, we used quantitative in situ hybridisation to examine mRNA expression of SNAREs (25 kDa synaptosome-associated protein (SNAP-25), syntaxin-1A and synaptobrevin-2) and SNARE-associated proteins (alpha-SNAP, CPLXI and CPLXII) in brain of R6/2 mice and their wild type littermates between 3 and 15 weeks of age. We found an early and progressive decrease of CPLXII expression in R6/2 mice brains. In contrast, no changes in SNARE expression were seen in R6/2 brains compared with wild type brain. Further, while decreased expression of alpha-SNAP and CPLXI was seen, this was not until 15 weeks of age and even then the changes were small. We suggest that downregulation of expression of mRNA encoding SNARE-associated proteins, first CPLXII and later CPLXI and alpha-SNAP, contributes to the progressive neuropathology of the R6/2 mouse model of Huntington's disease.
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Affiliation(s)
- Whitney Freeman
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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