1
|
Jiang A, Handley RR, Lehnert K, Snell RG. From Pathogenesis to Therapeutics: A Review of 150 Years of Huntington's Disease Research. Int J Mol Sci 2023; 24:13021. [PMID: 37629202 PMCID: PMC10455900 DOI: 10.3390/ijms241613021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a debilitating neurodegenerative genetic disorder caused by an expanded polyglutamine-coding (CAG) trinucleotide repeat in the huntingtin (HTT) gene. HD behaves as a highly penetrant dominant disorder likely acting through a toxic gain of function by the mutant huntingtin protein. Widespread cellular degeneration of the medium spiny neurons of the caudate nucleus and putamen are responsible for the onset of symptomology that encompasses motor, cognitive, and behavioural abnormalities. Over the past 150 years of HD research since George Huntington published his description, a plethora of pathogenic mechanisms have been proposed with key themes including excitotoxicity, dopaminergic imbalance, mitochondrial dysfunction, metabolic defects, disruption of proteostasis, transcriptional dysregulation, and neuroinflammation. Despite the identification and characterisation of the causative gene and mutation and significant advances in our understanding of the cellular pathology in recent years, a disease-modifying intervention has not yet been clinically approved. This review includes an overview of Huntington's disease, from its genetic aetiology to clinical presentation and its pathogenic manifestation. An updated view of molecular mechanisms and the latest therapeutic developments will also be discussed.
Collapse
Affiliation(s)
- Andrew Jiang
- Applied Translational Genetics Group, Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand; (R.R.H.); (K.L.); (R.G.S.)
| | | | | | | |
Collapse
|
2
|
Yan J, Bading H. The Disruption of NMDAR/TRPM4 Death Signaling with TwinF Interface Inhibitors: A New Pharmacological Principle for Neuroprotection. Pharmaceuticals (Basel) 2023; 16:1085. [PMID: 37631001 PMCID: PMC10458786 DOI: 10.3390/ph16081085] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 07/24/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
With the discovery that the acquisition of toxic features by extrasynaptic NMDA receptors (NMDARs) involves their physical interaction with the non-selective cation channel, TRPM4, it has become possible to develop a new pharmacological principle for neuroprotection, namely the disruption of the NMDAR/TRPM4 death signaling complex. This can be accomplished through the expression of the TwinF domain, a 57-amino-acid-long stretch of TRPM4 that mediates its interaction with NMDARs, but also using small molecule TwinF interface (TI) inhibitors, also known as NMDAR/TRPM4 interaction interface inhibitors. Both TwinF and small molecule TI inhibitors detoxify extrasynaptic NMDARs without interfering with synaptic NMDARs, which serve important physiological functions in the brain. As the toxic signaling of extrasynaptic NMDARs contributes to a wide range of neurodegenerative conditions, TI inhibitors may offer therapeutic options for currently untreatable human neurodegenerative diseases including Amyotrophic Lateral Sclerosis, Alzheimer's disease, and Huntington's disease.
Collapse
Affiliation(s)
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120 Heidelberg, Germany
| |
Collapse
|
3
|
Ogilvie AC, Schultz JL. Memantine Use and Cognitive Decline in Huntington's Disease: An Enroll-HD Study. Mov Disord Clin Pract 2023; 10:1120-1125. [PMID: 37476323 PMCID: PMC10354618 DOI: 10.1002/mdc3.13763] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 04/05/2023] [Accepted: 04/15/2023] [Indexed: 07/22/2023] Open
Abstract
Background Memantine is an N-methyl-d-aspartate (NMDA) receptor antagonist that is used to treat moderate to severe Alzheimer's Dementia (AD) and has been speculated to provide clinical benefits in Huntington's disease (HD). Objective To assess the effectiveness of memantine on the trajectory of cognitive decline in individuals with manifest HD. Methods Using participants from the Enroll-HD study, the primary analysis compared trajectories in cognition over a 5-year period using linear mixed effect models of prevalent and incident memantine users who were propensity-score-matched with non-users on measures of disease progression and demographics. Results In the primary analysis there were no significant differences in the trajectories between memantine users and non-users on any primary outcomes of interest. Conclusions Memantine use was not associated with any clinical benefit for individuals with manifest HD. Further studies are warranted to assess the impact of memantine on clinical outcomes in HD.
Collapse
Affiliation(s)
- Amy C. Ogilvie
- Department of EpidemiologyThe College of Public Health at the University of IowaIowa CityIAUSA
- Department of PsychiatryThe Carver College of Medicine at the University of IowaIowa CityIAUSA
| | - Jordan L. Schultz
- Department of PsychiatryThe Carver College of Medicine at the University of IowaIowa CityIAUSA
- Department of NeurologyThe Carver College of Medicine at the University of IowaIowa CityIAUSA
- Division of Pharmacy Practice and SciencesThe College of Pharmacy at the University of IowaIowa CityIAUSA
| |
Collapse
|
4
|
Danics L, Abbas AA, Kis B, Pircs K. Fountain of youth—Targeting autophagy in aging. Front Aging Neurosci 2023; 15:1125739. [PMID: 37065462 PMCID: PMC10090449 DOI: 10.3389/fnagi.2023.1125739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
As our society ages inexorably, geroscience and research focusing on healthy aging is becoming increasingly urgent. Macroautophagy (referred to as autophagy), a highly conserved process of cellular clearance and rejuvenation has attracted much attention due to its universal role in organismal life and death. Growing evidence points to autophagy process as being one of the key players in the determination of lifespan and health. Autophagy inducing interventions show significant improvement in organismal lifespan demonstrated in several experimental models. In line with this, preclinical models of age-related neurodegenerative diseases demonstrate pathology modulating effect of autophagy induction, implicating its potential to treat such disorders. In humans this specific process seems to be more complex. Recent clinical trials of drugs targeting autophagy point out some beneficial effects for clinical use, although with limited effectiveness, while others fail to show any significant improvement. We propose that using more human-relevant preclinical models for testing drug efficacy would significantly improve clinical trial outcomes. Lastly, the review discusses the available cellular reprogramming techniques used to model neuronal autophagy and neurodegeneration while exploring the existing evidence of autophagy’s role in aging and pathogenesis in human-derived in vitro models such as embryonic stem cells (ESCs), induced pluripotent stem cell derived neurons (iPSC-neurons) or induced neurons (iNs).
Collapse
Affiliation(s)
- Lea Danics
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- Hungarian Centre of Excellence for Molecular Medicine - Semmelweis University (HCEMM-SU), Neurobiology and Neurodegenerative Diseases Research Group, Budapest, Hungary
- Eötvös Loránd Research Network and Semmelweis University (ELKH-SU), Cerebrovascular and Neurocognitive Disorders Research Group, Budapest, Hungary
| | - Anna Anoir Abbas
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- Hungarian Centre of Excellence for Molecular Medicine - Semmelweis University (HCEMM-SU), Neurobiology and Neurodegenerative Diseases Research Group, Budapest, Hungary
| | - Balázs Kis
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- Hungarian Centre of Excellence for Molecular Medicine - Semmelweis University (HCEMM-SU), Neurobiology and Neurodegenerative Diseases Research Group, Budapest, Hungary
| | - Karolina Pircs
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- Hungarian Centre of Excellence for Molecular Medicine - Semmelweis University (HCEMM-SU), Neurobiology and Neurodegenerative Diseases Research Group, Budapest, Hungary
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, Lund University, Lund, Sweden
- *Correspondence: Karolina Pircs,
| |
Collapse
|
5
|
Kakoti BB, Bezbaruah R, Ahmed N. Therapeutic drug repositioning with special emphasis on neurodegenerative diseases: Threats and issues. Front Pharmacol 2022; 13:1007315. [PMID: 36263141 PMCID: PMC9574100 DOI: 10.3389/fphar.2022.1007315] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/12/2022] [Indexed: 11/21/2022] Open
Abstract
Drug repositioning or repurposing is the process of discovering leading-edge indications for authorized or declined/abandoned molecules for use in different diseases. This approach revitalizes the traditional drug discovery method by revealing new therapeutic applications for existing drugs. There are numerous studies available that highlight the triumph of several drugs as repurposed therapeutics. For example, sildenafil to aspirin, thalidomide to adalimumab, and so on. Millions of people worldwide are affected by neurodegenerative diseases. According to a 2021 report, the Alzheimer's disease Association estimates that 6.2 million Americans are detected with Alzheimer's disease. By 2030, approximately 1.2 million people in the United States possibly acquire Parkinson's disease. Drugs that act on a single molecular target benefit people suffering from neurodegenerative diseases. Current pharmacological approaches, on the other hand, are constrained in their capacity to unquestionably alter the course of the disease and provide patients with inadequate and momentary benefits. Drug repositioning-based approaches appear to be very pertinent, expense- and time-reducing strategies for the enhancement of medicinal opportunities for such diseases in the current era. Kinase inhibitors, for example, which were developed for various oncology indications, demonstrated significant neuroprotective effects in neurodegenerative diseases. This review expounds on the classical and recent examples of drug repositioning at various stages of drug development, with a special focus on neurodegenerative disorders and the aspects of threats and issues viz. the regulatory, scientific, and economic aspects.
Collapse
Affiliation(s)
- Bibhuti Bhusan Kakoti
- Department of Pharmaceutical Sciences, Faculty of Science and Engineering, Dibrugarh University, Dibrugarh, India
| | | | | |
Collapse
|
6
|
Lawlor M, Zigo M, Kerns K, Cho IK, Easley IV CA, Sutovsky P. Spermatozoan Metabolism as a Non-Traditional Model for the Study of Huntington’s Disease. Int J Mol Sci 2022; 23:ijms23137163. [PMID: 35806166 PMCID: PMC9266437 DOI: 10.3390/ijms23137163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 12/10/2022] Open
Abstract
Huntington’s Disease (HD) is a fatal autosomal dominant neurodegenerative disease manifested through motor dysfunction and cognitive deficits. Decreased fertility is also observed in HD animal models and HD male patients, due to altered spermatogenesis and sperm function, thus resulting in reduced fertilization potential. Although some pharmaceuticals are currently utilized to mitigate HD symptoms, an effective treatment that remedies the pathogenesis of the disease is yet to be approved by the FDA. Identification of genes and relevant diagnostic biomarkers and therapeutic target pathways including glycolysis and mitochondrial complex-I-dependent respiration may be advantageous for early diagnosis, management, and treatment of the disease. This review addresses the HD pathway in neuronal and sperm metabolism, including relevant gene and protein expression in both neurons and spermatozoa, indicated in the pathogenesis of HD. Furthermore, zinc-containing and zinc-interacting proteins regulate and/or are regulated by zinc ion homeostasis in both neurons and spermatozoa. Therefore, this review also aims to explore the comparative role of zinc in both neuronal and sperm function. Ongoing studies aim to characterize the products of genes implicated in HD pathogenesis that are expressed in both neurons and spermatozoa to facilitate studies of future treatment avenues in HD and HD-related male infertility. The emerging link between zinc homeostasis and the HD pathway could lead to new treatments and diagnostic methods linking genetic sperm defects with somatic comorbidities.
Collapse
Affiliation(s)
- Meghan Lawlor
- Division of Animal Science, University of Missouri, Columbia, MO 65211, USA; (M.L.); (M.Z.); (K.K.)
| | - Michal Zigo
- Division of Animal Science, University of Missouri, Columbia, MO 65211, USA; (M.L.); (M.Z.); (K.K.)
| | - Karl Kerns
- Division of Animal Science, University of Missouri, Columbia, MO 65211, USA; (M.L.); (M.Z.); (K.K.)
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - In Ki Cho
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; (I.K.C.); (C.A.E.IV)
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Charles A. Easley IV
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602, USA; (I.K.C.); (C.A.E.IV)
- Regenerative Bioscience Center, University of Georgia, Athens, GA 30602, USA
| | - Peter Sutovsky
- Division of Animal Science, University of Missouri, Columbia, MO 65211, USA; (M.L.); (M.Z.); (K.K.)
- Department of Obstetrics, Gynecology and Women’s Health, University of Missouri, Columbia, MO 65211, USA
- Correspondence: ; Tel.: +1-(573)-882-3329
| |
Collapse
|
7
|
Network medicine for disease module identification and drug repurposing with the NeDRex platform. Nat Commun 2021; 12:6848. [PMID: 34824199 PMCID: PMC8617287 DOI: 10.1038/s41467-021-27138-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/04/2021] [Indexed: 12/17/2022] Open
Abstract
Traditional drug discovery faces a severe efficacy crisis. Repurposing of registered drugs provides an alternative with lower costs and faster drug development timelines. However, the data necessary for the identification of disease modules, i.e. pathways and sub-networks describing the mechanisms of complex diseases which contain potential drug targets, are scattered across independent databases. Moreover, existing studies are limited to predictions for specific diseases or non-translational algorithmic approaches. There is an unmet need for adaptable tools allowing biomedical researchers to employ network-based drug repurposing approaches for their individual use cases. We close this gap with NeDRex, an integrative and interactive platform for network-based drug repurposing and disease module discovery. NeDRex integrates ten different data sources covering genes, drugs, drug targets, disease annotations, and their relationships. NeDRex allows for constructing heterogeneous biological networks, mining them for disease modules, prioritizing drugs targeting disease mechanisms, and statistical validation. We demonstrate the utility of NeDRex in five specific use-cases.
Collapse
|
8
|
Kim A, Lalonde K, Truesdell A, Gomes Welter P, Brocardo PS, Rosenstock TR, Gil-Mohapel J. New Avenues for the Treatment of Huntington's Disease. Int J Mol Sci 2021; 22:ijms22168363. [PMID: 34445070 PMCID: PMC8394361 DOI: 10.3390/ijms22168363] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/11/2022] Open
Abstract
Huntington’s disease (HD) is a neurodegenerative disorder caused by a CAG expansion in the HD gene. The disease is characterized by neurodegeneration, particularly in the striatum and cortex. The first symptoms usually appear in mid-life and include cognitive deficits and motor disturbances that progress over time. Despite being a genetic disorder with a known cause, several mechanisms are thought to contribute to neurodegeneration in HD, and numerous pre-clinical and clinical studies have been conducted and are currently underway to test the efficacy of therapeutic approaches targeting some of these mechanisms with varying degrees of success. Although current clinical trials may lead to the identification or refinement of treatments that are likely to improve the quality of life of those living with HD, major efforts continue to be invested at the pre-clinical level, with numerous studies testing novel approaches that show promise as disease-modifying strategies. This review offers a detailed overview of the currently approved treatment options for HD and the clinical trials for this neurodegenerative disorder that are underway and concludes by discussing potential disease-modifying treatments that have shown promise in pre-clinical studies, including increasing neurotropic support, modulating autophagy, epigenetic and genetic manipulations, and the use of nanocarriers and stem cells.
Collapse
Affiliation(s)
- Amy Kim
- Island Medical Program and Faculty of Medicine, University of British Columbia, Victoria, BC V8P 5C2, Canada; (A.K.); (K.L.)
| | - Kathryn Lalonde
- Island Medical Program and Faculty of Medicine, University of British Columbia, Victoria, BC V8P 5C2, Canada; (A.K.); (K.L.)
| | - Aaron Truesdell
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada;
- Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Priscilla Gomes Welter
- Neuroscience Graduate Program, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil; (P.G.W.); (P.S.B.)
| | - Patricia S. Brocardo
- Neuroscience Graduate Program, Federal University of Santa Catarina, Florianópolis 88040-900, Brazil; (P.G.W.); (P.S.B.)
| | - Tatiana R. Rosenstock
- Institute of Cancer and Genomic Science, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Department of Pharmacology, University of São Paulo, São Paulo 05508-000, Brazil
| | - Joana Gil-Mohapel
- Island Medical Program and Faculty of Medicine, University of British Columbia, Victoria, BC V8P 5C2, Canada; (A.K.); (K.L.)
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada;
- Correspondence: ; Tel.: +1-250-472-4597; Fax: +1-250-472-5505
| |
Collapse
|
9
|
Czeredys M. Dysregulation of Neuronal Calcium Signaling via Store-Operated Channels in Huntington's Disease. Front Cell Dev Biol 2020; 8:611735. [PMID: 33425919 PMCID: PMC7785827 DOI: 10.3389/fcell.2020.611735] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder that is characterized by motor, cognitive, and psychiatric problems. It is caused by a polyglutamine expansion in the huntingtin protein that leads to striatal degeneration via the transcriptional dysregulation of several genes, including genes that are involved in the calcium (Ca2+) signalosome. Recent research has shown that one of the major Ca2+ signaling pathways, store-operated Ca2+ entry (SOCE), is significantly elevated in HD. SOCE refers to Ca2+ flow into cells in response to the depletion of endoplasmic reticulum Ca2+ stores. The dysregulation of Ca2+ homeostasis is postulated to be a cause of HD progression because the SOCE pathway is indirectly and abnormally activated by mutant huntingtin (HTT) in γ-aminobutyric acid (GABA)ergic medium spiny neurons (MSNs) from the striatum in HD models before the first symptoms of the disease appear. The present review summarizes recent studies that revealed a relationship between HD pathology and elevations of SOCE in different models of HD, including YAC128 mice (a transgenic model of HD), cellular HD models, and induced pluripotent stem cell (iPSC)-based GABAergic medium spiny neurons (MSNs) that are obtained from adult HD patient fibroblasts. SOCE in MSNs was shown to be mediated by currents through at least two different channel groups, Ca2+ release-activated Ca2+ current (ICRAC) and store-operated Ca2+ current (ISOC), which are composed of stromal interaction molecule (STIM) proteins and Orai or transient receptor potential channel (TRPC) channels. Their role under physiological and pathological conditions in HD are discussed. The role of Huntingtin-associated protein 1 isoform A in elevations of SOCE in HD MSNs and potential compounds that may stabilize elevations of SOCE in HD are also summarized. Evidence is presented that shows that the dysregulation of molecular components of SOCE or pathways upstream of SOCE in HD MSN neurons is a hallmark of HD, and these changes could lead to HD pathology, making them potential therapeutic targets.
Collapse
Affiliation(s)
- Magdalena Czeredys
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| |
Collapse
|
10
|
Masnata M, Salem S, de Rus Jacquet A, Anwer M, Cicchetti F. Targeting Tau to Treat Clinical Features of Huntington's Disease. Front Neurol 2020; 11:580732. [PMID: 33329322 PMCID: PMC7710872 DOI: 10.3389/fneur.2020.580732] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/17/2020] [Indexed: 12/16/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by severe motor, cognitive and psychiatric impairments. While motor deficits often confirm diagnosis, cognitive dysfunctions usually manifest early in the disease process and are consistently ranked among the leading factors that impact the patients' quality of life. The genetic component of HD, a mutation in the huntingtin (HTT) gene, is traditionally presented as the main contributor to disease pathology. However, accumulating evidence suggests the implication of the microtubule-associated tau protein to the pathogenesis and therefore, proposes an alternative conceptual framework where tau and mutant huntingtin (mHTT) act conjointly to drive neurodegeneration and cognitive dysfunction. This perspective on disease etiology offers new avenues to design therapeutic interventions and could leverage decades of research on Alzheimer's disease (AD) and other tauopathies to rapidly advance drug discovery. In this mini review, we examine the breadth of tau-targeting treatments currently tested in the preclinical and clinical settings for AD and other tauopathies, and discuss the potential application of these strategies to HD.
Collapse
Affiliation(s)
- Maria Masnata
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Shireen Salem
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | - Aurelie de Rus Jacquet
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Mehwish Anwer
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec, Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| |
Collapse
|
11
|
Palomino‐Hernandez O, Margreiter MA, Rossetti G. Challenges in RNA Regulation in Huntington's Disease: Insights from Computational Studies. Isr J Chem 2020. [DOI: 10.1002/ijch.202000021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Oscar Palomino‐Hernandez
- Computational Biomedicine, Institute of Neuroscience and Medicine (INM-9)/Instute for advanced simulations (IAS-5)Forschungszentrum Juelich 52425 Jülich Germany
- Faculty 1RWTH Aachen 52425 Aachen Germany
- Computation-based Science and Technology Research CenterThe Cyprus Institute Nicosia 2121 Cyprus
- Institute of Life ScienceThe Hebrew University of Jerusalem Jerusalem 91904 Israel
| | - Michael A. Margreiter
- Computational Biomedicine, Institute of Neuroscience and Medicine (INM-9)/Instute for advanced simulations (IAS-5)Forschungszentrum Juelich 52425 Jülich Germany
- Faculty 1RWTH Aachen 52425 Aachen Germany
| | - Giulia Rossetti
- Computational Biomedicine, Institute of Neuroscience and Medicine (INM-9)/Instute for advanced simulations (IAS-5)Forschungszentrum Juelich 52425 Jülich Germany
- Jülich Supercomputing Centre (JSC)Forschungszentrum Jülich 52425 Jülich Germany
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation University Hospital AachenRWTH Aachen University Pauwelsstraße 30 52074 Aachen Germany
| |
Collapse
|
12
|
Kumar A, Kumar V, Singh K, Kumar S, Kim YS, Lee YM, Kim JJ. Therapeutic Advances for Huntington's Disease. Brain Sci 2020; 10:brainsci10010043. [PMID: 31940909 PMCID: PMC7016861 DOI: 10.3390/brainsci10010043] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023] Open
Abstract
Huntington’s disease (HD) is a progressive neurological disease that is inherited in an autosomal fashion. The cause of disease pathology is an expansion of cytosine-adenine-guanine (CAG) repeats within the huntingtin gene (HTT) on chromosome 4 (4p16.3), which codes the huntingtin protein (mHTT). The common symptoms of HD include motor and cognitive impairment of psychiatric functions. Patients exhibit a representative phenotype of involuntary movement (chorea) of limbs, impaired cognition, and severe psychiatric disturbances (mood swings, depression, and personality changes). A variety of symptomatic treatments (which target glutamate and dopamine pathways, caspases, inhibition of aggregation, mitochondrial dysfunction, transcriptional dysregulation, and fetal neural transplants, etc.) are available and some are in the pipeline. Advancement in novel therapeutic approaches include targeting the mutant huntingtin (mHTT) protein and the HTT gene. New gene editing techniques will reduce the CAG repeats. More appropriate and readily tractable treatment goals, coupled with advances in analytical tools will help to assess the clinical outcomes of HD treatments. This will not only improve the quality of life and life span of HD patients, but it will also provide a beneficial role in other inherited and neurological disorders. In this review, we aim to discuss current therapeutic research approaches and their possible uses for HD.
Collapse
Affiliation(s)
- Ashok Kumar
- Department of Genetics, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow 226014, UP, India;
| | - Vijay Kumar
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
- Correspondence: (V.K.); (J.-J.K.)
| | - Kritanjali Singh
- Central Research Station, Subharti Medical College, Swami Vivekanand Subharti University, Meerut 250002, India;
| | - Sukesh Kumar
- PG Department of Botany, Nalanda College, Bihar Sharif, Magadh University, Bihar 824234, India;
| | - You-Sam Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
| | - Yun-Mi Lee
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
| | - Jong-Joo Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
- Correspondence: (V.K.); (J.-J.K.)
| |
Collapse
|
13
|
Chang WT, Puspitasari F, Garcia-Miralles M, Yeow LY, Tay HC, Koh KB, Tan LJ, Pouladi MA, Chuang KH. Connectomic imaging reveals Huntington-related pathological and pharmaceutical effects in a mouse model. NMR IN BIOMEDICINE 2018; 31:e4007. [PMID: 30260561 DOI: 10.1002/nbm.4007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 07/05/2018] [Accepted: 07/31/2018] [Indexed: 06/08/2023]
Abstract
Recent studies suggest that neurodegenerative diseases could affect brain structure and function in disease-specific network patterns; however, how spontaneous activity affects structural covariance network (SC) is not clear. We hypothesized that hyper-excitability in Huntington disease (HD) disrupts the coordinated structural and functional connectivity, and treatment with memantine helps to reduce excitotoxicity and normalize the connectivity. MRI was conducted to measure somatosensory activation, resting-state functional-connectivity (rsFC), SC, amplitude of low frequency fluctuation (ALFF) and ALFF covariance (ALFFC) in the YAC128 mouse model of HD. We found somatosensory activation was unchanged but the subcortical ALFF was increased in HD mice, indicating subcortical but not cortical hyperactivity. The reduced sensorimotor rsFC but spared hippocampal and default mode networks in the HD mice was consistent with the more pronounced impairment in motor function compared with cognitive performance. The disease suppressed SC globally and reduced ALFFC in the basal ganglia network as well as its anti-correlation with the default mode network. By comparing these connectivity measures, we found that the originally coupled rsFC-SC relationship was impaired whereas SC-ALFFC correlation was increased by HD, suggesting disease facilitated covariation of brain volume and activity amplitude but not neural synchrony. The comparison with mono-synaptic axonal projection supports the hypothesis that rsFC, but not SC or ALFFC, is highly dependent on structural connectivity under healthy conditions. Treatment with memantine had a strong effect on normalizing the SC and reducing ALFF while slightly increasing other connectivity measures and restoring the rsFC-SC coupling, which is consistent with its effect on alleviating hyper-excitability and improving the coordinated neural growth. These results indicate that HD affects the cerebral structure-function relationship which could be partially reverted by NMDA antagonism. These connectivity measures provide unique insights into pathological and pharmaceutical effects in brain circuitry, and could be translatable biomarkers for evaluating drug effect and refining its efficacy.
Collapse
Affiliation(s)
- Wei-Tang Chang
- Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Fiftarina Puspitasari
- Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Marta Garcia-Miralles
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
| | - Ling Yun Yeow
- Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Hui-Chien Tay
- Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Katrianne Bethia Koh
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
| | - Liang Juin Tan
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
| | - Mahmoud A Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Medicine, National University of Singapore, Singapore, Singapore
| | - Kai-Hsiang Chuang
- Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
- Queensland Brain Institute, University of Queensland, Brisbane, Australia
- Centre for Advanced Imaging, University of Queensland, Brisbane, Australia
| |
Collapse
|
14
|
Potkin KT, Potkin SG. New directions in therapeutics for Huntington disease. FUTURE NEUROLOGY 2018; 13:101-121. [PMID: 30800004 DOI: 10.2217/fnl-2017-0035] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/06/2018] [Indexed: 11/21/2022]
Abstract
Huntington disease (HD) is an autosomal dominantly inherited neurodegenerative disease that affects motor, cognitive and psychiatric functions, and ultimately leads to death. The pathology of the disease is based on an expansion of CAG repeats in exon 1 of the huntingtin gene on chromosome 4, which produces a mutant huntingtin protein (mHtt). This protein is involved in neurotoxicity and brain atrophy, and can form β-sheets and abnormal mHtt aggregates. Currently, there are no approved effective treatments for HD, although tetrabenazine (Xenazine™) and deutetrabenazine (AUSTEDO™) have been approved for treatment of the motor symptom chorea in HD. This literature review aims to address the latest research on promising therapeutics based on influencing the hypothesized pathological mechanisms.
Collapse
Affiliation(s)
- Katya T Potkin
- Stony Brook School of Medicine, 101 Nicolls Rd, Stony Brook, NY 11794, USA.,Stony Brook School of Medicine, 101 Nicolls Rd, Stony Brook, NY 11794, USA
| | - Steven G Potkin
- Professor Emeritus, Department of Psychiatry & Human Behavior, University of California, Irvine, CA 92697, USA.,Professor Emeritus, Department of Psychiatry & Human Behavior, University of California, Irvine, CA 92697, USA
| |
Collapse
|
15
|
Durães F, Pinto M, Sousa E. Old Drugs as New Treatments for Neurodegenerative Diseases. Pharmaceuticals (Basel) 2018; 11:ph11020044. [PMID: 29751602 PMCID: PMC6027455 DOI: 10.3390/ph11020044] [Citation(s) in RCA: 168] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases are increasing in number, given that the general global population is becoming older. They manifest themselves through mechanisms that are not fully understood, in many cases, and impair memory, cognition and movement. Currently, no neurodegenerative disease is curable, and the treatments available only manage the symptoms or halt the progression of the disease. Therefore, there is an urgent need for new treatments for this kind of disease, since the World Health Organization has predicted that neurodegenerative diseases affecting motor function will become the second-most prevalent cause of death in the next 20 years. New therapies can come from three main sources: synthesis, natural products, and existing drugs. This last source is known as drug repurposing, which is the most advantageous, since the drug’s pharmacokinetic and pharmacodynamic profiles are already established, and the investment put into this strategy is not as significant as for the classic development of new drugs. There have been several studies on the potential of old drugs for the most relevant neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, Multiple Sclerosis and Amyotrophic Lateral Sclerosis.
Collapse
Affiliation(s)
- Fernando Durães
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
- CIIMAR, Interdisciplinary Center of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos P, 4450-208 Matosinhos, Portugal.
| | - Madalena Pinto
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
- CIIMAR, Interdisciplinary Center of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos P, 4450-208 Matosinhos, Portugal.
| | - Emília Sousa
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
- CIIMAR, Interdisciplinary Center of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos P, 4450-208 Matosinhos, Portugal.
| |
Collapse
|
16
|
Mackay JP, Nassrallah WB, Raymond LA. Cause or compensation?-Altered neuronal Ca 2+ handling in Huntington's disease. CNS Neurosci Ther 2018; 24:301-310. [PMID: 29427371 DOI: 10.1111/cns.12817] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/11/2018] [Accepted: 01/11/2018] [Indexed: 02/03/2023] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder of typically middle-aged onset for which there is no disease-modifying treatment. Caudate and putamen medium-sized spiny projection neurons (SPNs) most severely degenerate in HD. However, it is unclear why mutant huntingtin protein (mHTT) is preferentially toxic to these neurons or why symptoms manifest only relatively late in life. mHTT interacts with numerous neuronal proteins. Likewise, multiple SPN cellular processes have been described as altered in various HD models. Among these, altered neuronal Ca2+ influx and intracellular Ca2+ handling feature prominently and are addressed here. Specifically, we focus on extrasynaptic NMDA-type glutamate receptors, endoplasmic reticulum IP3 receptors, and mitochondria. As mHTT is expressed throughout development, compensatory processes will likely be mounted to mitigate any deleterious effects. Although some compensations can lessen mHTT's disruptive effects, others-such as upregulation of the ER-refilling store-operated Ca2+ channel response-contribute to pathogenesis. A causation-based approach is therefore necessary to decipher the complex sequence of events linking mHTT to neurodegeneration, and to design rational therapeutic interventions. With this in mind, we highlight evidence, or lack thereof, that the above alterations in Ca2+ handling occur early in the disease process, clearly interact with mHTT, and show disease-modifying potential when reversed in animals.
Collapse
Affiliation(s)
- James P Mackay
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wissam B Nassrallah
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.,Graduate Program in Neuroscience and MD/PhD Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lynn A Raymond
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
17
|
Abstract
Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disease characterized by progressive motor, behavioral, and cognitive decline, ending in death. Despite the discovery of the underlying genetic mutation more than 20 years ago, treatment remains focused on symptomatic management. Chorea, the most recognizable symptom, responds to medication that reduces dopaminergic neurotransmission. Psychiatric symptoms such as depression and anxiety may also respond well to symptomatic therapies. Unfortunately, many other symptoms do not respond to current treatments. Furthermore, high-quality evidence for treatment of HD in general remains limited. To date, there has been minimal success with identifying a disease-modifying therapy based upon molecular models. However, one of the emerging gene silencing techniques may provide a breakthrough in treating this devastating disease.
Collapse
Affiliation(s)
- Kara J Wyant
- Department of Neurology, University of Michigan, 1324 Taubman Center, SPC 5322, 1500 E. Medical Center Drive, Ann Arbor, 48109-5322, USA.
| | - Andrew J Ridder
- Department of Neurology, University of Michigan, 1324 Taubman Center, SPC 5322, 1500 E. Medical Center Drive, Ann Arbor, 48109-5322, USA
| | - Praveen Dayalu
- Department of Neurology, University of Michigan, 1324 Taubman Center, SPC 5322, 1500 E. Medical Center Drive, Ann Arbor, 48109-5322, USA
| |
Collapse
|
18
|
Veerman SRT, Schulte PFJ, Deijen JB, de Haan L. Adjunctive memantine in clozapine-treated refractory schizophrenia: an open-label 1-year extension study. Psychol Med 2017; 47:363-375. [PMID: 27776560 DOI: 10.1017/s0033291716002476] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND In a recent placebo-controlled, double-blind crossover trial (n = 52), significant beneficial effects on memory (d = 0.30) and negative symptoms (d = 0.29) were found after 12 weeks of memantine augmentation in patients with clozapine-refractory schizophrenia. In this open-label 1-year extension study we report the long-term effects and tolerability of memantine add-on therapy to clozapine. METHOD Completers of the first trial who experienced beneficial effects during 12 weeks of memantine treatment received memantine for 1 year. Primary endpoints were memory and executive function using the Cambridge Neuropsychological Test Automated Battery, the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression Severity Scale (CGI-S). RESULTS Of 31 randomized controlled trial completers who experienced beneficial effects from memantine, 24 received memantine for 1 year. The small improvement in memory found in the memantine condition in the placebo-controlled trial remained stable in the extension study. Executive function did not improve. After 26 weeks of memantine add-on therapy to clozapine, PANSS negative symptoms (r = 0.53), PANSS positive symptoms (r = 0.50) and PANSS total symptoms (r = 0.54) significantly improved. Even further significant improvement in all these measures was observed between 26 weeks and 52 weeks of memantine, with effect sizes varying from 0.39 to 0.51. CGI-S showed a non-significant moderate improvement at 26 weeks (r = 0.36) and 52 weeks (r = 0.34). Memantine was well tolerated without serious adverse effects. CONCLUSIONS In the 1-year extension phase the favourable effect of adjunctive memantine on memory was sustained and we observed further improvement of negative, positive and overall symptoms in patients with clozapine-treated refractory schizophrenia.
Collapse
Affiliation(s)
- S R T Veerman
- Mental Health Service Noord-Holland Noord,Community Mental Health Division,Flexible Assertive Community Treatment,Alkmaar,The Netherlands
| | - P F J Schulte
- Mental Health Service Noord-Holland Noord,Division for Specialized Treatment,Treatment Centre for Bipolar Disorders,Alkmaar,The Netherlands
| | - J B Deijen
- Vrije Universiteit,Faculty of Behavioural and Movement Sciences,Section Clinical Neuropsychology,Amsterdam,The Netherlands
| | - L de Haan
- Early Psychosis Department,Academic Medical Centre,University of Amsterdam,Academic Psychiatric Centre,Arkin,Amsterdam,The Netherlands
| |
Collapse
|
19
|
Majláth Z, Török N, Toldi J, Vécsei L. Memantine and Kynurenic Acid: Current Neuropharmacological Aspects. Curr Neuropharmacol 2016; 14:200-9. [PMID: 26564141 PMCID: PMC4825950 DOI: 10.2174/1570159x14666151113123221] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/22/2015] [Accepted: 12/03/2015] [Indexed: 12/31/2022] Open
Abstract
Glutamatergic neurotransmission, of special importance in the human brain, is implicated in key brain functions such as synaptic plasticity and memory. The excessive activation of N-methyl- D-aspartate (NMDA) receptors may result in excitotoxic neuronal damage; this process has been implicated in the pathomechanism of different neurodegenerative disorders, such as Alzheimer’s disease (AD). Memantine is an uncompetitive antagonist of NMDA receptors with a favorable pharmacokinetic profile, and is therefore clinically well tolerated. Memantine is approved for the treatment of AD, but may additionally be beneficial for other dementia forms and pain conditions. Kynurenic acid
(KYNA) is an endogenous antagonist of NMDA receptors which has been demonstrated under experimental conditions to be neuroprotective. The development of a well-tolerated NMDA antagonist may offer a novel therapeutic option for the treatment of neurodegenerative disease and pain syndromes. KYNA may be a valuable candidate for future drug development.
Collapse
Affiliation(s)
| | | | | | - László Vécsei
- Department of Neurology, Faculty of Medicine, University of Szeged, Albert Szent-Györgyi Clinical Center, Semmelweis u. 6. H-6725 Szeged, Hungary.
| |
Collapse
|
20
|
Neuropeptide Y (NPY) as a therapeutic target for neurodegenerative diseases. Neurobiol Dis 2016; 95:210-24. [PMID: 27461050 DOI: 10.1016/j.nbd.2016.07.022] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/29/2016] [Accepted: 07/20/2016] [Indexed: 12/16/2022] Open
Abstract
Neuropeptide Y (NPY) and NPY receptors are widely expressed in the mammalian central nervous system. Studies in both humans and rodent models revealed that brain NPY levels are altered in some neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and Machado-Joseph disease. In this review, we will focus on the roles of NPY in the pathological mechanisms of these disorders, highlighting NPY as a neuroprotective agent, as a neural stem cell proliferative agent, as an agent that increases trophic support, as a stimulator of autophagy and as an inhibitor of excitotoxicity and neuroinflammation. Moreover, the effect of NPY in some clinical manifestations commonly observed in Alzheimer's disease, Parkinson's disease, Huntington's disease and Machado-Joseph disease, such as depressive symptoms and body weight loss, are also discussed. In conclusion, this review highlights NPY system as a potential therapeutic target in neurodegenerative diseases.
Collapse
|
21
|
Mason SL, Barker RA. Novel targets for Huntington's disease: future prospects. Degener Neurol Neuromuscul Dis 2016; 6:25-36. [PMID: 30050366 PMCID: PMC6053088 DOI: 10.2147/dnnd.s83808] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is an incurable, inherited, progressive, neurodegenerative disorder that is characterized by a triad of motor, cognitive, and psychiatric problems. Despite the noticeable increase in therapeutic trials in HD in the last 20 years, there have, to date, been very few significant advances. The main hope for new and emerging therapeutics for HD is to develop a neuroprotective compound capable of slowing down or even stopping the progression of the disease and ultimately prevent the subtle early signs from developing into manifest disease. Recently, there has been a noticeable shift away from symptomatic therapies in favor of more mechanistic-based interventions, a change driven by a better understanding of the pathogenesis of this disorder. In this review, we discuss the status of, and supporting evidence for, potential novel treatments of HD that are currently under development or have reached the level of early Phase I/II clinical trials.
Collapse
Affiliation(s)
| | - Roger A Barker
- John van Geest Centre for Brain Repair, .,Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| |
Collapse
|
22
|
Cunha MP, Lieberknecht V, Ramos-Hryb AB, Olescowicz G, Ludka FK, Tasca CI, Gabilan NH, Rodrigues ALS. Creatine affords protection against glutamate-induced nitrosative and oxidative stress. Neurochem Int 2016; 95:4-14. [PMID: 26804444 DOI: 10.1016/j.neuint.2016.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 01/07/2016] [Accepted: 01/18/2016] [Indexed: 12/11/2022]
Abstract
Creatine has been reported to exert beneficial effects in several neurodegenerative diseases in which glutamatergic excitotoxicity and oxidative stress play an etiological role. The purpose of this study was to investigate the protective effects of creatine, as compared to the N-Methyl-d-Aspartate (NMDA) receptor antagonist dizocilpine (MK-801), against glutamate or hydrogen peroxide (H2O2)-induced injury in human neuroblastoma SH-SY5Y cells. Exposure of cells to glutamate (60-80 mM) or H2O2 (200-300 μM) for 24 h decreased cellular viability and increased dichlorofluorescein (DCF) fluorescence (indicative of increased reactive oxygen species, ROS) and nitric oxide (NO) production (assessed by mono-nitrogen oxides, NOx, levels). Creatine (1-10 mM) or MK-801 (0.1-10 μM) reduced glutamate- and H2O2-induced toxicity. The protective effect of creatine against glutamate-induced toxicity involves its antioxidant effect, since creatine, similar to MK-801, prevented the increase on DCF fluorescence induced by glutamate or H2O2. Furthermore, creatine or MK-801 blocked glutamate- and H2O2-induced increases in NOx levels. In another set of experiments, the repeated, but not acute, administration of creatine (300 mg/kg, po) in mice prevented the decreases on cellular viability and mitochondrial membrane potential (assessed by tetramethylrhodamine ethyl ester, TMRE, probe) of hippocampal slices incubated with glutamate (10 mM). Creatine concentration-dependent decreased the amount of nitrite formed in the reaction of oxygen with NO produced from sodium nitroprusside solution, suggesting that its protective effect against glutamate or H2O2-induced toxicity might be due to its scavenger activity. Overall, the results suggest that creatine may be useful as adjuvant therapy for neurodegenerative disease treatments.
Collapse
Affiliation(s)
- Mauricio P Cunha
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil.
| | - Vicente Lieberknecht
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Ana Belén Ramos-Hryb
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Gislaine Olescowicz
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Fabiana K Ludka
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Carla I Tasca
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Nelson H Gabilan
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| | - Ana Lúcia S Rodrigues
- Department of Biochemistry, Center of Biological Sciences, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, 88040-900, Florianópolis, SC, Brazil
| |
Collapse
|
23
|
Lauterbach EC. Six psychotropics for pre-symptomatic & early Alzheimer's (MCI), Parkinson's, and Huntington's disease modification. Neural Regen Res 2016; 11:1712-1726. [PMID: 28123400 PMCID: PMC5204212 DOI: 10.4103/1673-5374.194708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The quest for neuroprotective drugs to slow the progression of neurodegenerative diseases (NDDs), including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), has been largely unrewarding. Preclinical evidence suggests that repurposing quetiapine, lithium, valproate, fluoxetine, donepezil, and memantine for early and pre-symptomatic disease-modification in NDDs may be promising and can spare regulatory barriers. The literature of these psychotropics in early stage and pre-symptomatic AD, PD, and HD is reviewed and propitious findings follow. Mild cognitive impairment (MCI) phase of AD: salutary human randomized controlled trial findings for low-dose lithium and, in selected patients, donepezil await replication. Pre-symptomatic AD: human epidemiological data indicate that lithium reduces AD risk. Animal model studies (AMS) reveal encouraging results for quetiapine, lithium, donepezil, and memantine. Early PD: valproate AMS findings show promise. Pre-symptomatic PD: lithium and valproate AMS findings are encouraging. Early HD: uncontrolled clinical data indicate non-progression with lithium, fluoxetine, donepezil, and memantine. Pre-symptomatic HD: lithium and valproate are auspicious in AMS. Many other promising findings awaiting replication (valproate in MCI; lithium, valproate, fluoxetine in pre-symptomatic AD; lithium in early PD; lithium, valproate, fluoxetine in pre-symptomatic PD; donepezil in early HD; lithium, fluoxetine, memantine in pre-symptomatic HD) are reviewed. Dose- and stage-dependent effects are considered. Suggestions for signal-enhancement in human trials are provided for each NDD stage.
Collapse
Affiliation(s)
- Edward C Lauterbach
- Professor Emeritus of Psychiatry and Neurology, Mercer University School of Medicine, Macon, GA, USA
| |
Collapse
|
24
|
Gonzalez G, DiGirolamo G, Romero-Gonzalez M, Smelson D, Ziedonis D, Kolodziej M. Memantine improves buprenorphine/naloxone treatment for opioid dependent young adults. Drug Alcohol Depend 2015; 156:243-253. [PMID: 26454835 PMCID: PMC4652072 DOI: 10.1016/j.drugalcdep.2015.09.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 09/11/2015] [Accepted: 09/15/2015] [Indexed: 01/24/2023]
Abstract
BACKGROUND Opioid use disorders are considered a serious public health problem among young adults. Current treatment is limited to long-term opioid substitution therapy, with high relapse rates after discontinuation. This study evaluated the co-administration of memantine to brief buprenorphine pharmacotherapy as a treatment alternative. METHODS 13-week double-blind placebo-controlled trial evaluating 80 young adult opioid dependent participants treated with buprenorphine/naloxone 16-4mg/day and randomized to memantine (15mg or 30mg) or placebo. Primary outcomes were a change in the weekly mean proportion of opioid use, and cumulative abstinence rates after rapid buprenorphine discontinuation on week 9. RESULTS Treatment retention was not significantly different between groups. The memantine 30mg group was significantly less likely to relapse and to use opioids after buprenorphine discontinuation. Among participants abstinent on week 8, those in the memantine 30mg group (81.9%) were significantly less likely to relapse after buprenorphine was discontinued compared to the placebo group (30%) (p<0.025). Also, the memantine 30mg group had significantly reduced opioid use (mean=0, SEM±0.00) compared to the placebo group (mean=0.33, SEM±0.35; p<0.004) during the last 2 weeks of study participation. CONCLUSIONS Memantine 30mg significantly improved short-term treatment with buprenorphine/naloxone for opioid dependent young adults by reducing relapse and opioid use after buprenorphine discontinuation. Combined short-term treatment with buprenorphine/naloxone may be an effective alternative treatment to long-term methadone or buprenorphine maintenance in young adults.
Collapse
Affiliation(s)
- Gerardo Gonzalez
- Division of Addiction Psychiatry, University of Massachusetts Medical School, USA; VA Central Western Massachusetts Healthcare System, USA; MAYU of New England, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Abstract
Huntington disease (HD) is an autosomal dominant inherited neurodegenerative disease characterized by progressive motor, behavioral, and cognitive decline, culminating in death. It is caused by an expanded CAG repeat in the huntingtin gene. Even years before symptoms become overt, mutation carriers show subtle but progressive striatal and cerebral white matter atrophy by volumetric MRI. Although there is currently no direct treatment of HD, management options are available for several symptoms. A better understanding of HD pathogenesis, and more sophisticated clinical trials using newer biomarkers, may lead to meaningful treatments. This article reviews the current knowledge of HD pathogenesis and treatment.
Collapse
Affiliation(s)
- Praveen Dayalu
- Department of Neurology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Roger L Albin
- Department of Neurology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA; Neuroscience Research, Veterans Affairs Medical Center, 2215 Fuller Road, Ann Arbor, MI 48105, USA
| |
Collapse
|
26
|
N-Acetylcysteine improves mitochondrial function and ameliorates behavioral deficits in the R6/1 mouse model of Huntington's disease. Transl Psychiatry 2015; 5:e492. [PMID: 25562842 PMCID: PMC4312826 DOI: 10.1038/tp.2014.131] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/06/2014] [Accepted: 10/26/2014] [Indexed: 12/02/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder, involving psychiatric, cognitive and motor symptoms, caused by a CAG-repeat expansion encoding an extended polyglutamine tract in the huntingtin protein. Oxidative stress and excitotoxicity have previously been implicated in the pathogenesis of HD. We hypothesized that N-acetylcysteine (NAC) may reduce both excitotoxicity and oxidative stress through its actions on glutamate reuptake and antioxidant capacity. The R6/1 transgenic mouse model of HD was used to investigate the effects of NAC on HD pathology. It was found that chronic NAC administration delayed the onset and progression of motor deficits in R6/1 mice, while having an antidepressant-like effect on both R6/1 and wild-type mice. A deficit in the astrocytic glutamate transporter protein, GLT-1, was found in R6/1 mice. However, this deficit was not ameliorated by NAC, implying that the therapeutic effect of NAC is not due to rescue of the GLT-1 deficit and associated glutamate-induced excitotoxicity. Assessment of mitochondrial function in the striatum and cortex revealed that R6/1 mice show reduced mitochondrial respiratory capacity specific to the striatum. This deficit was rescued by chronic treatment with NAC. There was a selective increase in markers of oxidative damage in mitochondria, which was rescued by NAC. In conclusion, NAC is able to delay the onset of motor deficits in the R6/1 model of Huntington's disease and it may do so by ameliorating mitochondrial dysfunction. Thus, NAC shows promise as a potential therapeutic agent in HD. Furthermore, our data suggest that NAC may also have broader antidepressant efficacy.
Collapse
|
27
|
Abstract
Changes in the level and activity of brain-derived neurotrophic factor (BDNF) have been described in a number of neurodegenerative disorders since early 1990s. However, only in Huntington disease (HD) gain- and loss-of-function experiments have mechanistically linked these abnormalities with the genetic defect.In this chapter we will describe how huntingtin protein, whose mutation causes HD, is involved in the physiological control of BDNF synthesis and transport in neurons and how both processes are simultaneously disrupted in HD. We will describe the underlying molecular mechanisms and discuss pre-clinical data concerning the impact of the experimental manipulation of BDNF levels on HD progression. These studies have revealed that a major loss of BDNF protein in the brain of HD patients may contribute to the clinical manifestations of the disease. The experimental strategies under investigation to increase brain BDNF levels in animal models of HD will also be described, with a view to ultimately improving the clinical treatment of this condition.
Collapse
Affiliation(s)
- Chiara Zuccato
- Department of Biosciences and Centre for Stem cell Research, Università degli Studi di Milano, Via Viotti 3/5, 20133, Milan, Italy,
| | | |
Collapse
|
28
|
Chakraborty J, Rajamma U, Mohanakumar KP. A mitochondrial basis for Huntington's disease: therapeutic prospects. Mol Cell Biochem 2013; 389:277-91. [PMID: 24374792 DOI: 10.1007/s11010-013-1951-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Accepted: 12/19/2013] [Indexed: 01/12/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant disease, with overt movement dysfunctions. Despite focused research on the basis of neurodegeneration in HD for last few decades, the mechanism for the site-specific lesion of neurons in the brain is not clear. All the explanations that partially clarify the phenomenon of neurodegeneration leads to one organelle, mitochondrion, which is severely affected in HD at the level of electron transport chain, Ca(2+) buffering efficiency and morphology. But, with the existing knowledge, it is not clear whether the cell death processes in HD initiate from mitochondria, though the Huntingtin (Htt) aggregates show close proximity to this organelle, or do some extracellular stimuli like TNFα or FasL trigger the process. Mainly because of the disparity in the different available experimental models, the results are quite confusing or at least inconsistent to a great extent. The fact remains that the mutant Htt protein was seen to be associated with mitochondria directly, and as the striatum is highly enriched with dopamine and glutamate, it may make the striatal mitochondria more vulnerable because of the presence of dopa-quinones, and due to an imbalance in Ca(2+). The current therapeutic strategies are based on symptomatic relief, and, therefore, mainly target neurotransmitter(s) and their receptors to modulate behavioral outputs, but none of them targets mitochondria or try to address the basic molecular events that cause neurons to die in discrete regions of the brain, which could probably be resulting from grave mitochondrial dysfunctions. Therefore, targeting mitochondria for their protection, while addressing symptomatic recovery, holds a great potential to tone down the progression of the disease, and to provide better relief to the patients and caretakers.
Collapse
Affiliation(s)
- J Chakraborty
- Laboratory of Clinical and Experimental Neuroscience, Division of Cell Biology & Physiology, CSIR-Indian Institute of Chemical Biology, Rooms 117&119, 4, Raja S. C. Mullick Road, Kolkata, 700 032, India
| | | | | |
Collapse
|
29
|
Abstract
Synaptic activity initiates biochemical processes that have various outcomes, including the formation of memories, increases in neuronal survival and the development of chronic pain and addiction. Virtually all activity-induced, long-lasting adaptations of brain functions require a dialogue between synapses and the nucleus that results in changes in gene expression. Calcium signals that are induced by synaptic activity and propagate into the nucleus are a major route for synapse-to-nucleus communication. Recent findings indicate that diverse forms of neuroadaptation require calcium transients in the nucleus to switch on the necessary genomic programme. Deficits in nuclear calcium signalling as a result of a reduction in synaptic activity or increased extrasynaptic NMDA receptor signalling may underlie the aetiologies of various diseases, including neurodegeneration and cognitive dysfunction.
Collapse
Affiliation(s)
- Hilmar Bading
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany. Hilmar.Bading@ uni-hd.de
| |
Collapse
|
30
|
Gil-Mohapel JM. Screening of therapeutic strategies for Huntington's disease in YAC128 transgenic mice. CNS Neurosci Ther 2012; 18:77-86. [PMID: 21501423 DOI: 10.1111/j.1755-5949.2011.00246.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Huntington’s disease (HD) is a hereditary neurodegenerative disorder caused by an unstable expansion of cytosine-adenine-guanine (CAG) repeats in the HD gene. The symptoms include cognitive dysfunction and severe motor impairment with loss of voluntary movement coordination that is later replaced by bradykinesia and rigidity. The neuropathology is characterized by neuronal loss mainly in the striatum and cortex, and the appearance of neuronal intranuclear inclusions of mutant huntingtin. The mechanisms responsible for neurodegeneration are still not fully understood although excitotoxicity and a consequent increase in intracellular calcium concentration as well as the activation of caspases and calapins are known to play a key role. There is currently no satisfactory treatment or cure for this disease. The YAC128 transgenic mice express the full-length human HD gene with 128 CAG repeats and constitute a unique model for the study of HD as they replicate the slow and biphasic progression of behavioral deficits characteristic of the human condition and show striatal neuronal loss. As such, these transgenic mice have been an invaluable model not only for the elucidation of the neurodegenerative pathways in HD, but also for the screening and development of new therapeutic approaches. Here, I will review the unique characteristics of this transgenic HD model and will provide a summary of the therapies that have been tested in these mice, namely: potentiation of the protective roles of wild-type huntingtin and mutant huntingtin aggregation, transglutaminase inhibition, inhibition of glutamate- and dopamine-induced toxicity, apoptosis inhibition, use of essential fatty acids, and the novel approach of intrabody gene therapy. The insights obtained from these and future studies will help identify potential candidates for clinical trials and will ultimately contribute to the discovery of a successful treatment for this devastating neurodegenerative disorder.
Collapse
Affiliation(s)
- Joana M Gil-Mohapel
- Division of Medical Sciences, Island Medical Program, University of Victoria, British Columbia, Canada.
| |
Collapse
|
31
|
Ehrnhoefer DE, Wong BKY, Hayden MR. Convergent pathogenic pathways in Alzheimer's and Huntington's diseases: shared targets for drug development. Nat Rev Drug Discov 2011; 10:853-67. [PMID: 22015920 DOI: 10.1038/nrd3556] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases, exemplified by Alzheimer's disease and Huntington's disease, are characterized by progressive neuropsychiatric dysfunction and loss of specific neuronal subtypes. Although there are differences in the exact sites of pathology, and the clinical profiles of these two conditions only partially overlap, considerable similarities in disease mechanisms and pathogenic pathways can be observed. These shared mechanisms raise the possibility of exploiting common therapeutic targets for drug development. As Huntington's disease has a monogenic cause, it is possible to accurately identify individuals who carry the Huntington's disease mutation but do not yet manifest symptoms. These individuals could act as a model for Alzheimer's disease to test therapeutic interventions that target shared pathogenic pathways.
Collapse
Affiliation(s)
- Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, British Columbia V5Z 4H4, Canada
| | | | | |
Collapse
|
32
|
Abstract
It has been more than 17 years since the causative mutation for Huntington's disease was discovered as the expansion of the triplet repeat in the N-terminal portion of the Huntingtin (HTT) gene. In the intervening time, researchers have discovered a great deal about Huntingtin's involvement in a number of cellular processes. However, the role of Huntingtin in the key pathogenic mechanism leading to neurodegeneration in the disease process has yet to be discovered. Here, we review the body of knowledge that has been uncovered since gene discovery and include discussions of the HTT gene, CAG triplet repeat expansion, HTT expression, protein features, posttranslational modifications, and many of its known protein functions and interactions. We also highlight potential pathogenic mechanisms that have come to light in recent years.
Collapse
Affiliation(s)
- Karen N McFarland
- Department of Neurology, University of Florida, Gainesville, FL 32610-0236, USA.
| | | |
Collapse
|
33
|
Ondo WG, Shinawi L, Davidson A, Lai D. Memantine for non-motor features of Parkinson's disease: a double-blind placebo controlled exploratory pilot trial. Parkinsonism Relat Disord 2010; 17:156-9. [PMID: 21193343 DOI: 10.1016/j.parkreldis.2010.12.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 11/03/2010] [Accepted: 12/03/2010] [Indexed: 11/29/2022]
Abstract
OBJECT To perform an exploratory study evaluating memantine for several common non-motor problems in Parkinson's disease. METHODS We conducted a single center, double-blind, placebo controlled pilot trial of memantine, titrated to 20 mg/day, in PD subjects. Inclusion criteria were intentionally broad and included both fluctuating and non-fluctuating patients. After baseline assessments, subjects (N = 40) were randomized to drug and placebo groups. They received a battery of traditional and non-motor assessments. After a safety call (2 weeks after baseline) they returned for identical assessments at week 8. An 8-week open label extension was started if desired. RESULTS Subject demographics (age 69.1 ± 7.8; 24 males), were similar in the drug and placebo groups. Four dropped from the study while on drug vs. none on placebo. Two of 36 remaining dropped out over the 8-week open label section. Of the 34 who completed the final open label visit, 24 elected to be prescribed memantine after the study. During the controlled trial, there was no significant change in UPDRS section I or II, Epworth sleepiness scale, fatigue severity scale, Hamilton depression scale, Conner adult inventory, PD Quality of Life-39, or clinical global impressions. UPDRS "on" motor scores tended to improved, p = 0.19. CONCLUSION Memantine was well tolerated in PD; however, specific measures of sleepiness, fatigue, depression, and attention did not significantly improve. The majority of subjects elected to stay on the drug after the open label extension suggesting some unassessed benefit.
Collapse
Affiliation(s)
- William G Ondo
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
| | | | | | | |
Collapse
|
34
|
Miller BR, Bezprozvanny I. Corticostriatal circuit dysfunction in Huntington's disease: intersection of glutamate, dopamine and calcium. FUTURE NEUROLOGY 2010; 5:735-756. [PMID: 21977007 DOI: 10.2217/fnl.10.41] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Huntington's disease (HD) is a noncurable and progressive autosomal-dominant neurodegenerative disorder that results from a polyglutamine expansion in the amino-terminal region of the huntingtin protein. The generation of rodent HD models has revealed that cellular dysfunction, rather than cell death alone, occurs early in the disease progression, appearing even before overt symptom onset. Much evidence has now established that dysfunction of the corticostriatal circuit is key to HD symptomology. In this article, we summarize the most current findings that implicate glutamate, dopamine and calcium signaling in this system and discuss how they work in concert to disrupt corticostriatal function. In addition, we highlight therapeutic strategies related to altered corticostriatal signaling in HD.
Collapse
Affiliation(s)
- Benjamin Ray Miller
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | | |
Collapse
|
35
|
Rammes G, Danysz W, Parsons CG. Pharmacodynamics of memantine: an update. Curr Neuropharmacol 2010; 6:55-78. [PMID: 19305788 PMCID: PMC2645549 DOI: 10.2174/157015908783769671] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 05/10/2007] [Accepted: 11/05/2007] [Indexed: 01/12/2023] Open
Abstract
Memantine received marketing authorization from the European Agency for the Evaluation of Medicinal Products (EMEA) for the treatment of moderately severe to severe Alzheimer s disease (AD) in Europe on 17(th) May 2002 and shortly thereafter was also approved by the FDA for use in the same indication in the USA. Memantine is a moderate affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist with strong voltage-dependency and fast kinetics. Due to this mechanism of action (MOA), there is a wealth of other possible therapeutic indications for memantine and numerous preclinical data in animal models support this assumption. This review is intended to provide an update on preclinical studies on the pharmacodynamics of memantine, with an additional focus on animal models of diseases aside from the approved indication. For most studies prior to 1999, the reader is referred to a previous review [196].In general, since 1999, considerable additional preclinical evidence has accumulated supporting the use of memantine in AD (both symptomatic and neuroprotective). In addition, there has been further confirmation of the MOA of memantine as an uncompetitive NMDA receptor antagonist and essentially no data contradicting our understanding of the benign side effect profile of memantine.
Collapse
Affiliation(s)
- G Rammes
- Clinical Neuropharmacology, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | | | | |
Collapse
|
36
|
Huang K, Kang MH, Askew C, Kang R, Sanders SS, Wan J, Davis NG, Hayden MR. Palmitoylation and function of glial glutamate transporter-1 is reduced in the YAC128 mouse model of Huntington disease. Neurobiol Dis 2010; 40:207-15. [PMID: 20685337 DOI: 10.1016/j.nbd.2010.05.027] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 05/20/2010] [Accepted: 05/25/2010] [Indexed: 11/29/2022] Open
Abstract
Excitotoxicity plays a key role in the selective vulnerability of striatal neurons in Huntington disease (HD). Decreased glutamate uptake by glial cells could account for the excess glutamate at the synapse in patients as well as animal models of HD. The major molecule responsible for clearing glutamate at the synapses is glial glutamate transporter GLT-1. In this study, we show that GLT-1 is palmitoylated at cysteine38 (C38) and further, that this palmitoylation is drastically reduced in HD models both in vitro and in vivo. Palmitoylation is required for normal GLT-1 function. Blocking palmitoylation either with the general palmitoylation inhibitor, 2-bromopalmitate, or with a GLT-1 C38S mutation, severely impairs glutamate uptake activity. In addition, GLT-1-mediated glutamate uptake is indeed impaired in the YAC128 HD mouse brain, with the defect in the striatum evident as early as 3 months prior to obvious neuropathological findings, and in both striatum and cortex at 12 months. These phenotypes are not a result of changes in GLT1 protein expression, suggesting a crucial role of palmitoylation in GLT-1 function. Thus, it appears that impaired GLT-1 palmitoylation is present early in the pathogenesis of HD, and may influence decreased glutamate uptake, excitotoxicity, and ultimately, neuronal cell death in HD.
Collapse
Affiliation(s)
- Kun Huang
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | | | | | | | | |
Collapse
|
37
|
SANTHAKUMAR V, JONES RT, MODY I. Developmental regulation and neuroprotective effects of striatal tonic GABAA currents. Neuroscience 2010; 167:644-55. [PMID: 20206233 PMCID: PMC2907073 DOI: 10.1016/j.neuroscience.2010.02.048] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 02/17/2010] [Accepted: 02/19/2010] [Indexed: 11/24/2022]
Abstract
Striatal neurons are known to express GABA(A) receptor subunits that underlie both phasic and tonic inhibition. Striatal projection neurons, or medium spiny neurons (MSNs), are divided into two classes: MSNs containing the dopamine D1 receptor (D1-MSNs) form the direct pathway to the substantia nigra and facilitate movement while MSNs expressing the dopamine D2 receptor (D2-MSNs) form the pallidal pathway that inhibits movement. Consequently, modulating inhibition in distinct classes of MSNs will differentially impact downstream network activity and motor behavior. Given the powerful role of extrasynaptic inhibition in controlling neuronal excitability, we examined the nature of striatal tonic inhibition and its potential role in preventing excitotoxicity. Consistent with earlier studies in young (P16-P25) mice, tonic GABA currents in D2-MSNs were larger than in D1-MSNs. However, with age (>P30 mice) the tonic GABA currents increased in D1-MSNs but decreased in D2-MSNs. These data demonstrate a developmental switch in the MSN subtype expressing larger tonic GABA currents. Compared to wild-type, MSNs from adult mice lacking the GABA(A)R delta subunit (Gabrd(-/-) mice) had both decreased tonic GABA currents and reduced survival following an in vitro excitotoxic challenge with quinolinic acid. Furthermore, muscimol-induced tonic GABA currents were accompanied by reduced acute swelling of striatal neurons after exposure to NMDA in WT mice but not in Gabrd(-/-) mice. Our data are consistent with a role for tonic inhibition mediated by GABA(A)R delta subunits in neuroprotection against excitotoxic insults in the adult striatum.
Collapse
Affiliation(s)
- V. SANTHAKUMAR
- Departments of Neurology and Physiology, David Geffen School of Medicine at the University of California, Los Angeles, CA 90095, USA
| | - R. T. JONES
- Departments of Neurology and Physiology, David Geffen School of Medicine at the University of California, Los Angeles, CA 90095, USA
- Neurobiology Graduate Program, University of California, Los Angeles, CA 90095, USA
| | - I. MODY
- Departments of Neurology and Physiology, David Geffen School of Medicine at the University of California, Los Angeles, CA 90095, USA
| |
Collapse
|
38
|
Tarawneh R, Galvin JE. Potential future neuroprotective therapies for neurodegenerative disorders and stroke. Clin Geriatr Med 2010; 26:125-47. [PMID: 20176298 PMCID: PMC2828394 DOI: 10.1016/j.cger.2009.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The cellular mechanisms underlying neuronal loss and neurodegeneration have been an area of interest in the last decade. Although neurodegenerative diseases such as Alzheimer disease, Parkinson disease, and Huntington disease each have distinct clinical symptoms and pathologies, they all share common mechanisms such as protein aggregation, oxidative injury, inflammation, apoptosis, and mitochondrial injury that contribute to neuronal loss. Although cerebrovascular disease has different causes from the neurodegenerative disorders, many of the same common disease mechanisms come into play following a stroke. Novel therapies that target each of these mechanisms may be effective in decreasing the risk of disease, abating symptoms, or slowing down their progression. Although most of these therapies are experimental, and require further investigation, a few seem to offer promise.
Collapse
Affiliation(s)
- Rawan Tarawneh
- Alzheimer Disease Research Center, Washington University School of Medicine, St Louis, MO, 63108
- Department of Neurology, Washington University School of Medicine, St Louis, MO, 63108
| | - James E. Galvin
- Alzheimer Disease Research Center, Washington University School of Medicine, St Louis, MO, 63108
- Department of Neurobiology, Washington University School of Medicine, St Louis, MO, 63108
| |
Collapse
|
39
|
|
40
|
Balance between synaptic versus extrasynaptic NMDA receptor activity influences inclusions and neurotoxicity of mutant huntingtin. Nat Med 2009; 15:1407-13. [PMID: 19915593 PMCID: PMC2789858 DOI: 10.1038/nm.2056] [Citation(s) in RCA: 320] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 10/02/2009] [Indexed: 02/07/2023]
Abstract
The neurodegenerative disorder Huntington disease (HD) is caused by an expanded CAG repeat in the huntingtin gene, resulting in loss of striatal and cortical neurons. Although, the gene product is widely expressed, it remains unclear why neurons are selectively targeted. Here, we demonstrate the relationship between synaptic and extrasynaptic activity, inclusion formation of mutant huntingtin protein (mtHtt), and neuronal survival. Synaptic NMDA receptor (NMDAR) activity induces mtHtt inclusions via a TCP1 ring complex (TRiC)-dependent mechanism, rendering neurons more resistant to mtHtt-mediated cell death. In contrast, stimulation of extrasynaptic NMDARs increases vulnerability of mtHtt-neurons to cell death by impairing a neuroprotective CREB—PGC-1α cascade and increasing the small guanine nucleotide-binding protein Rhes, which is known to sumoylate and disaggregate mtHtt. Treatment of transgenic YAC128 HD mice with low-dose memantine blocks extrasynaptic (but not synaptic) NMDARs and ameliorates neuropathological and behavioral manifestations. By contrast, high-dose memantine also blocks synaptic NMDAR activity, decreases neuronal inclusions, and worsens these outcomes. Our findings offer a rational therapeutic approach for protecting susceptible neurons in HD.
Collapse
|
41
|
Thomas SJ, Grossberg GT. Memantine: a review of studies into its safety and efficacy in treating Alzheimer's disease and other dementias. Clin Interv Aging 2009; 4:367-77. [PMID: 19851512 PMCID: PMC2762361 DOI: 10.2147/cia.s6666] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Memantine is an uncompetitive N-methyl-D-aspartate receptor antagonist with moderate affinity. Its mechanism of action is neuroprotective and potentially therapeutic in several neuropsychiatric diseases. It has been approved by the FDA for the treatment of moderate to severe Alzheimer's disease (AD) either as a monotherapy or in combination with cholinesterase inhibitors. This review covers key studies of memantine's safety and efficacy in treating moderate to severe AD. It also covers current research into other dementias including but not exclusively mild AD and vascular dementia. Other studies on the efficacy of memantine for other neuropsychiatric diseases are discussed. Memantine is a safe and effective drug that merits further research on several topics. Clinicians should be aware of new studies and potential uses of memantine because of its safety and efficacy.
Collapse
Affiliation(s)
- Stuart J Thomas
- Department of Neurology and Psychiatry, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - George T Grossberg
- Department of Neurology and Psychiatry, Saint Louis University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
42
|
Abstract
BACKGROUND Cognitive symptoms are associated with functional disability in Huntington disease; yet, few controlled trials have examined cognitive treatments that could improve patient independence and quality of life. Atomoxetine is a norepinephrine reuptake inhibitor approved for treatment of attention-deficit/hyperactivity disorder. METHODS Twenty participants with mild Huntington disease who complained of inattention were randomized to receive atomoxetine (80 mg/d) or placebo in a 10-week double-blind crossover study. Primary outcome measures were self-reported attention and attention and executive neuropsychological composite scores. Secondary outcomes were psychiatric and motor symptom scores. RESULTS The rate of reported adverse effects while on atomoxetine was 56% (vs 35% on placebo), which most commonly included dry mouth (39%), loss of appetite (22%), insomnia (22%), and dizziness (17%). There were no serious adverse events related to atomoxetine. There were statistically significant, although mild, increases in heart rate and diastolic blood pressure on atomoxetine, consistent with other studies and not requiring medical referral. There were no significant improvements while on atomoxetine compared with placebo on primary outcomes. However, there was evidence of significant placebo effects on self-reported attention and psychiatric functions. There were no group differences on the Unified Huntington's Disease Rating total motor score. CONCLUSIONS Atomoxetine demonstrated no advantages over placebo for primary or secondary outcomes. Although atomoxetine was not effective at improving attention at this dose, its safety and tolerability were similar to other studies.
Collapse
|
43
|
Abstract
Huntington's disease (HD) is a relentless neurodegenerative disease that results in profound disability through a triad of motor, cognitive and neuropsychiatric symptoms. At present, there are very few therapeutic interventions available with the exception of a limited number of drugs that offer mild symptomatic relief. Although the genetic basis of the disease has been identified, the mechanisms behind the cellular pathogenesis are still not clear and as a result no candidate drugs with the potential for disease modification have been found clinically until now. One of the major limitations in assessing the usefulness of drug treatments in HD is the lack of well-designed, double-blind, placebo-controlled clinical trials. Most studies have been open-label, using a small number of patients and tend to concentrate on the motor features of the disease, primarily the chorea. This review discusses the treatments now used for HD before evaluating the newer drugs at present being explored in both the clinic and in the laboratory in mouse models of the disease.
Collapse
Affiliation(s)
- Sarah L Mason
- Cambridge Centre for Brain Repair, ED Adrian Building, Forvie Site, Robinson Way, Cambridge CB20PY, UK.
| | | |
Collapse
|
44
|
Bauer PO, Nukina N. The pathogenic mechanisms of polyglutamine diseases and current therapeutic strategies. J Neurochem 2009; 110:1737-65. [PMID: 19650870 DOI: 10.1111/j.1471-4159.2009.06302.x] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Expansion of CAG trinucleotide repeat within the coding region of several genes results in the production of proteins with expanded polyglutamine (PolyQ) stretch. The expression of these pathogenic proteins leads to PolyQ diseases, such as Huntington's disease or several types of spinocerebellar ataxias. This family of neurodegenerative disorders is characterized by constant progression of the symptoms and molecularly, by the accumulation of mutant proteins inside neurons causing their dysfunction and eventually death. So far, no effective therapy actually preventing the physical and/or mental decline has been developed. Experimental therapeutic strategies either target the levels or processing of mutant proteins in an attempt to prevent cellular deterioration, or they are aimed at the downstream pathologic effects to reverse or ameliorate the caused damages. Certain pathomechanistic aspects of PolyQ disorders are discussed here. Relevance of disease models and recent knowledge of therapeutic possibilities is reviewed and updated.
Collapse
Affiliation(s)
- Peter O Bauer
- Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Saitama, Japan
| | | |
Collapse
|
45
|
Mestre T, Ferreira J, Coelho MM, Rosa M, Sampaio C. Therapeutic interventions for disease progression in Huntington's disease. Cochrane Database Syst Rev 2009; 2009:CD006455. [PMID: 19588392 PMCID: PMC7390161 DOI: 10.1002/14651858.cd006455.pub2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal dominant neurodegenerative disease with an average onset between the fourth and fifth decade of life; it leads to death 15 to 20 years after the onset of symptoms. Although several drugs seem effective in controlling the incapacitating manifestations of HD, no specific therapy is known. The present review aims at analysing the best available data on therapeutic interventions investigated with the goal of modifying the progression of the disease as measured in terms of survival, disability or progression of HD core symptoms. OBJECTIVES Evaluate the effectiveness of therapeutic interventions aimed at modifying disease progression in HD. SEARCH STRATEGY The search strategy developed for the Movement Disorders Group was undertaken. The Cochrane Controlled Trials Register, Medline, EMBASE and Clinical Trials Database of the United States National Institute of Health were thoroughly searched until December 2007. SELECTION CRITERIA All randomised, double-blinded, placebo-controlled clinical trials of therapeutics investigated with the goal of modifying disease progression in HD were included. Participants should have genetically confirmed diagnosis of HD or compatible symptoms and a family history. Trials had a follow-up duration of more than three months and at least ten participants. All pharmacological and non-pharmacological interventions were included. DATA COLLECTION AND ANALYSIS Two reviewers independently assessed the eligibility of identified trials. The methodological quality was assessed and eligible data were registered onto standardised forms. An intention-to-treat analysis was conducted, when feasible. If data were not available in the original publication, the principal investigator of the trial was contacted for further information. A meta-analysis was to be conducted when possible; otherwise, a descriptive summary of the results was provided. The software Revman 5.0.15 was used for statistical analysis. MAIN RESULTS Eight trials were included involving a total of 1366 HD patients. The duration of the studies ranged between 30 and 144 weeks (median: 52 weeks). The following interventions were selected: vitamin E, Idebenone, Baclofen, Lamotrigine, creatine, coenzyme Q10 + Remacemide, ethyl-eicosapentanoic acid and Riluzole. No trials produced positive results for the selected efficacy outcome measures. A descriptive summary of the trials is provided. The selected interventions were found to be generally safe and well tolerated. AUTHORS' CONCLUSIONS Only pharmacological interventions were included and none proved to be effective as a disease-modifying therapy for HD. Further trials with greater methodological quality should be conducted using more sensitive biological markers. Pre-symptomatic mutation carriers should be included in future studies.
Collapse
Affiliation(s)
- Tiago Mestre
- Institute of Molecular MedicineNeurological Clinical Research UnitHospital de Santa MariaAv. Prof. Egas MonizLisboaPortugal1649‐028
| | - Joaquim Ferreira
- Faculdade de Medicina de LisboaLaboratório de Farmacologia Clínica e TerapêuticaHospital de Santa MariaAv. Prof. Egas MonizLisboaPortugal1649‐028
| | - Miguel M Coelho
- Faculdade de Medicina de LisboaLaboratório de Farmacologia Clínica e TerapêuticaHospital de Santa MariaAv. Prof. Egas MonizLisboaPortugal1649‐028
| | - Mário Rosa
- Institute of Molecular MedicineNeurological Clinical Research UnitHospital de Santa MariaAv. Prof. Egas MonizLisboaPortugal1649‐028
| | - Cristina Sampaio
- Faculdade de Medicina de LisboaLaboratório de Farmacologia Clínica e TerapêuticaHospital de Santa MariaAv. Prof. Egas MonizLisboaPortugal1649‐028
| | | |
Collapse
|
46
|
Coba MP, Pocklington AJ, Collins MO, Kopanitsa MV, Uren RT, Swamy S, Croning MDR, Choudhary JS, Grant SGN. Neurotransmitters drive combinatorial multistate postsynaptic density networks. Sci Signal 2009; 2:ra19. [PMID: 19401593 PMCID: PMC3280897 DOI: 10.1126/scisignal.2000102] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mammalian postsynaptic density (PSD) comprises a complex collection of approximately 1100 proteins. Despite extensive knowledge of individual proteins, the overall organization of the PSD is poorly understood. Here, we define maps of molecular circuitry within the PSD based on phosphorylation of postsynaptic proteins. Activation of a single neurotransmitter receptor, the N-methyl-D-aspartate receptor (NMDAR), changed the phosphorylation status of 127 proteins. Stimulation of ionotropic and metabotropic glutamate receptors and dopamine receptors activated overlapping networks with distinct combinatorial phosphorylation signatures. Using peptide array technology, we identified specific phosphorylation motifs and switching mechanisms responsible for the integration of neurotransmitter receptor pathways and their coordination of multiple substrates in these networks. These combinatorial networks confer high information-processing capacity and functional diversity on synapses, and their elucidation may provide new insights into disease mechanisms and new opportunities for drug discovery.
Collapse
Affiliation(s)
- Marcelo P. Coba
- Genes to Cognition, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Andrew J. Pocklington
- Institute for Adaptive and Neural Computation, Division of Informatics, University of Edinburgh, 5 Forrest Hill, Edinburgh EH1 2QL, UK
| | - Mark O. Collins
- Proteomic Mass Spectrometry, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Maksym V. Kopanitsa
- Genes to Cognition, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Rachel T. Uren
- Genes to Cognition, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Sajani Swamy
- Proteomic Mass Spectrometry, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Mike D. R. Croning
- Genes to Cognition, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Jyoti S. Choudhary
- Proteomic Mass Spectrometry, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Seth G. N. Grant
- Genes to Cognition, Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| |
Collapse
|
47
|
Mattson MP. Glutamate and neurotrophic factors in neuronal plasticity and disease. Ann N Y Acad Sci 2009; 1144:97-112. [PMID: 19076369 DOI: 10.1196/annals.1418.005] [Citation(s) in RCA: 410] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Glutamate's role as a neurotransmitter at synapses has been known for 40 years, but glutamate has since been shown to regulate neurogenesis, neurite outgrowth, synaptogenesis, and neuron survival in the developing and adult mammalian nervous system. Cell-surface glutamate receptors are coupled to Ca(2+) influx and release from endoplasmic reticulum stores, which causes rapid (kinase- and protease-mediated) and delayed (transcription-dependent) responses that change the structure and function of neurons. Neurotrophic factors and glutamate interact to regulate developmental and adult neuroplasticity. For example, glutamate stimulates the production of brain-derived neurotrophic factor (BDNF), which, in turn, modifies neuronal glutamate sensitivity, Ca(2+) homeostasis, and plasticity. Neurotrophic factors may modify glutamate signaling directly, by changing the expression of glutamate receptor subunits and Ca(2+)-regulating proteins, and also indirectly by inducing the production of antioxidant enzymes, energy-regulating proteins, and antiapoptotic Bcl-2 family members. Excessive activation of glutamate receptors, under conditions of oxidative and metabolic stress, may contribute to neuronal dysfunction and degeneration in diseases ranging from stroke and Alzheimer's disease to psychiatric disorders. By enhancing neurotrophic factor signaling, environmental factors such as exercise and dietary energy restriction, and chemicals such as antidepressants may optimize glutamatergic signaling and protect against neurological disorders.
Collapse
Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA.
| |
Collapse
|
48
|
Glutamate toxicity in the striatum of the R6/2 Huntington's disease transgenic mice is age-dependent and correlates with decreased levels of glutamate transporters. Neurobiol Dis 2009; 34:78-86. [PMID: 19168136 DOI: 10.1016/j.nbd.2008.12.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 12/10/2008] [Accepted: 12/15/2008] [Indexed: 01/13/2023] Open
Abstract
Glutamate excitotoxicity has been implicated in the neuropathology of Huntington's disease (HD), due to the toxicity of glutamate receptor agonists on striatal medium spiny neurons (MSN), the most affected neuronal population in HD. Previous studies showed functional alterations of NMDA glutamate receptors and decreased expression of glutamate transporters in transgenic models and HD patients, suggesting the presence of excitotoxic damage. We have studied the vulnerability of the striatum to glutamate toxicity in R6/2 mice at 10 and 14 weeks of age. At 10 weeks R6/2 and wild-type mice are equally vulnerable to glutamate toxicity, while at 14 weeks transgenic mice show increased damage, as assessed by Nissl and Fluoro Jade staining. In addition, increased electrical brain activity is observed after glutamate administration in transgenic mice, as monitored electroencephalographically. According to western blot analysis, increased vulnerability to glutamate toxicity correlates with decreased levels of GLT-1 and GLAST glutamate transporters in the striatum.
Collapse
|
49
|
Pathophysiology of Huntington's disease: from huntingtin functions to potential treatments. Curr Opin Neurol 2008; 21:497-503. [PMID: 18607213 DOI: 10.1097/wco.0b013e328304b692] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Drugs used to treat Huntington's disease act on the symptoms but do not slow the disease process itself. This review focuses on recent pathogenetic findings and on emerging therapeutic approaches. RECENT FINDINGS Basic research is providing novel insights into the complex molecular pathways involved in the pathogenesis of Huntington's disease. Several mechanisms have been identified that mediate neuronal dysfunction and death; these include neuronal aggregation of the mutated protein, transcriptional dysregulation, excitotoxicity, altered energy metabolism, impaired axonal transport, and altered synaptic transmission. Recent experimental works have identified potential new therapeutic targets. In particular, they emphasize the role of altered histone modifications in transcriptional dysregulation, the synergistic action of glutamatergic and dopaminergic pathways in inducing excitotoxicity, the neuroprotective effect of brain-derived neurotrophic factor expression and transport restoration, and the possibility of reducing the expression of the mutant protein huntingtin and its deleterious effects by using short interfering mRNAs. SUMMARY Successful neuroprotective therapy for Huntington's disease patients is likely to involve a combined approach targeting both cellular and molecular mediators that account for the toxicity of mutated huntingtin.
Collapse
|
50
|
Abstract
Huntington's disease (HD) is a devastating autosomal dominant neurodegenerative disease caused by a CAG trinucleotide repeat expansion encoding an abnormally long polyglutamine tract in the huntingtin protein. Much has been learnt since the mutation was identified in 1993. We review the functions of wild-type huntingtin. Mutant huntingtin may cause toxicity via a range of different mechanisms. The primary consequence of the mutation is to confer a toxic gain of function on the mutant protein and this may be modified by certain normal activities that are impaired by the mutation. It is likely that the toxicity of mutant huntingtin is revealed after a series of cleavage events leading to the production of N-terminal huntingtin fragment(s) containing the expanded polyglutamine tract. Although aggregation of the mutant protein is a hallmark of the disease, the role of aggregation is complex and the arguments for protective roles of inclusions are discussed. Mutant huntingtin may mediate some of its toxicity in the nucleus by perturbing specific transcriptional pathways. HD may also inhibit mitochondrial function and proteasome activity. Importantly, not all of the effects of mutant huntingtin may be cell-autonomous, and it is possible that abnormalities in neighbouring neurons and glia may also have an impact on connected cells. It is likely that there is still much to learn about mutant huntingtin toxicity, and important insights have already come and may still come from chemical and genetic screens. Importantly, basic biological studies in HD have led to numerous potential therapeutic strategies.
Collapse
|