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Mitre M, Mariga A, Chao MV. Neurotrophin signalling: novel insights into mechanisms and pathophysiology. Clin Sci (Lond) 2017; 131:13-23. [PMID: 27908981 PMCID: PMC5295469 DOI: 10.1042/cs20160044] [Citation(s) in RCA: 172] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 07/18/2016] [Accepted: 08/09/2016] [Indexed: 12/29/2022]
Abstract
Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are prominent regulators of neuronal survival, growth and differentiation during development. While trophic factors are viewed as well-understood but not innovative molecules, there are many lines of evidence indicating that BDNF plays an important role in the pathophysiology of many neurodegenerative disorders, depression, anxiety and other psychiatric disorders. In particular, lower levels of BDNF are associated with the aetiology of Alzheimer's and Huntington's diseases. A major challenge is to explain how neurotrophins are able to induce plasticity, improve learning and memory and prevent age-dependent cognitive decline through receptor signalling. This article will review the mechanism of action of neurotrophins and how BDNF/tropomyosin receptor kinase B (TrkB) receptor signaling can dictate trophic responses and change brain plasticity through activity-dependent stimulation. Alternative approaches for modulating BDNF/TrkB signalling to deliver relevant clinical outcomes in neurodegenerative and neuropsychiatric disorders will also be described.
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Affiliation(s)
- Mariela Mitre
- Neuroscience and Physiology and Psychiatry, New York University School of Medicine, New York, NY 10016, U.S.A.
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, U.S.A
| | - Abigail Mariga
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, U.S.A
- Departments of Cell Biology, New York University School of Medicine, New York, NY 10016, U.S.A
| | - Moses V Chao
- Neuroscience and Physiology and Psychiatry, New York University School of Medicine, New York, NY 10016, U.S.A
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, U.S.A
- Departments of Cell Biology, New York University School of Medicine, New York, NY 10016, U.S.A
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52
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Mariga A, Mitre M, Chao MV. Consequences of brain-derived neurotrophic factor withdrawal in CNS neurons and implications in disease. Neurobiol Dis 2017; 97:73-79. [PMID: 27015693 PMCID: PMC5295364 DOI: 10.1016/j.nbd.2016.03.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/20/2016] [Accepted: 03/09/2016] [Indexed: 01/07/2023] Open
Abstract
Growth factor withdrawal has been studied across different species and has been shown to have dramatic consequences on cell survival. In the nervous system, withdrawal of nerve growth factor (NGF) from sympathetic and sensory neurons results in substantial neuronal cell death, signifying a requirement for NGF for the survival of neurons in the peripheral nervous system (PNS). In contrast to the PNS, withdrawal of central nervous system (CNS) enriched brain-derived neurotrophic factor (BDNF) has little effect on cell survival but is indispensible for synaptic plasticity. Given that most early events in neuropsychiatric disorders are marked by a loss of synapses, lack of BDNF may thus be an important part of a cascade of events that leads to neuronal degeneration. Here we review reports on the effects of BDNF withdrawal on CNS neurons and discuss the relevance of the loss in disease.
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Affiliation(s)
- Abigail Mariga
- Department of Cell Biology, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
| | - Mariela Mitre
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
| | - Moses V Chao
- Department of Cell Biology, New York University School of Medicine, New York, NY, 10016, United States; Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, United States; Department of Psychiatry, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
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53
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Josephy-Hernandez S, Jmaeff S, Pirvulescu I, Aboulkassim T, Saragovi HU. Neurotrophin receptor agonists and antagonists as therapeutic agents: An evolving paradigm. Neurobiol Dis 2016; 97:139-155. [PMID: 27546056 DOI: 10.1016/j.nbd.2016.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 08/10/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative disorders are prevalent, complex and devastating conditions, with very limited treatment options currently available. While they manifest in many forms, there are commonalities that link them together. In this review, we will focus on neurotrophins - a family of related factors involved in neuronal development and maintenance. Neurodegenerative diseases often present with a neurotrophin imbalance, in which there may be decreases in trophic signaling through Trk receptors for example, and/or increases in pro-apoptotic activity through p75. Clinical trials with neurotrophins have continuously failed due to their poor pharmacological properties as well as the unavoidable activation of p75. Thus, there is a need for drugs without such setbacks. Small molecule neurotrophin mimetics are favorable options since they can selectively activate Trks or inactivate p75. In this review, we will initially present a brief outline of how these molecules are synthesized and their mechanisms of action; followed by an update in the current state of neurotrophins and small molecules in major neurodegenerative diseases. Although there has been significant progress in the development of potential therapeutics, more studies are needed to establish clear mechanisms of action and target specificity in order to transition from animal models to the assessment of safety and use in humans.
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Affiliation(s)
- Sylvia Josephy-Hernandez
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Sean Jmaeff
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Iulia Pirvulescu
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Tahar Aboulkassim
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - H Uri Saragovi
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada.
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54
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Warnault V, Darcq E, Morisot N, Phamluong K, Wilbrecht L, Massa SM, Longo FM, Ron D. The BDNF Valine 68 to Methionine Polymorphism Increases Compulsive Alcohol Drinking in Mice That Is Reversed by Tropomyosin Receptor Kinase B Activation. Biol Psychiatry 2016; 79:463-73. [PMID: 26204799 PMCID: PMC4676961 DOI: 10.1016/j.biopsych.2015.06.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 05/26/2015] [Accepted: 06/01/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND The valine 66 to methionine (Met) polymorphism within the brain-derived neurotrophic factor (BDNF) sequence reduces activity-dependent BDNF release and is associated with psychiatric disorders in humans. Alcoholism is one of the most prevalent psychiatric diseases. Here, we tested the hypothesis that this polymorphism increases the severity of alcohol abuse disorders. METHODS We generated transgenic mice carrying the mouse homolog of the human Met66BDNF allele (Met68BDNF) and used alcohol-drinking paradigms in combination with viral-mediated gene delivery and pharmacology. RESULTS We found that Met68BDNF mice consumed excessive amounts of alcohol and continued to drink despite negative consequences, a hallmark of addiction. Importantly, compulsive alcohol intake was reversed by overexpression of the wild-type valine68BDNF allele in the ventromedial prefrontal cortex of the Met68BDNF mice or by systemic administration of the tropomyosin receptor kinase B agonist, LM22A-4. CONCLUSIONS Our findings suggest that carrying this BDNF allele increases the risk of developing uncontrolled and excessive alcohol drinking that can be reversed by directly activating the BDNF receptor, tropomyosin receptor kinase B. Importantly, this work identifies a potential therapeutic strategy for the treatment of compulsive alcohol drinking in humans carrying the Met66BDNF allele.
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Affiliation(s)
- Vincent Warnault
- Department of Neurology, University of California, San Francisco, San Francisco
| | - Emmanuel Darcq
- Department of Neurology, University of California, San Francisco, San Francisco
| | - Nadege Morisot
- Department of Neurology, University of California, San Francisco, San Francisco
| | - Khanhky Phamluong
- Department of Neurology, University of California, San Francisco, San Francisco
| | - Linda Wilbrecht
- Department of Psychology, University of California, Berkeley, Berkeley
| | - Stephen M Massa
- Department of Neurology, University of California, San Francisco, San Francisco; Laboratory for Computational Neurochemistry and Drug Discovery and Department of Veterans Affairs Medical Center, University of California, San Francisco, San Francisco
| | - Frank M Longo
- Department of Neurology and Neurological Sciences (FML), Stanford University School of Medicine, Stanford, California
| | - Dorit Ron
- Department of Neurology, University of California, San Francisco, San Francisco.
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Shannon KM, Fraint A. Therapeutic advances in Huntington's Disease. Mov Disord 2015; 30:1539-46. [DOI: 10.1002/mds.26331] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 06/15/2015] [Indexed: 01/09/2023] Open
Affiliation(s)
- Kathleen M. Shannon
- Department of Neurological Sciences; Rush Medical College; Chicago Illinois USA
| | - Avram Fraint
- Department of Neurological Sciences; Rush Medical College; Chicago Illinois USA
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56
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Kron M, Lang M, Adams IT, Sceniak M, Longo F, Katz DM. A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome. Dis Model Mech 2015; 7:1047-55. [PMID: 25147297 PMCID: PMC4142725 DOI: 10.1242/dmm.016030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Reduced levels of brain-derived neurotrophic factor (BDNF) are thought to contribute to the pathophysiology of Rett syndrome (RTT), a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2). In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS) and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to behavioral arousal in symptomatic RTT mice.
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Affiliation(s)
- Miriam Kron
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Min Lang
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Ian T Adams
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Michael Sceniak
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Frank Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - David M Katz
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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Abstract
BACKGROUND Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by hyperkinetic movements, psychiatric (e.g. depression and psychosis) and cognitive symptoms (frontal lobe dementia). In Germany approximately 8000 patients suffer from HD. OBJECTIVES The paper reviews the clinical course, epidemiology, genetics, differential diagnoses, pathophysiology, symptomatics and causal treatment options. METHODS Publications on animal and human HD studies and trials and reviews available in Medline have been taken into account. RESULTS Only genetic testing allows diagnostic certainty. The CAG repeat length influences age of onset, disease course and life expectancy. The mechanism by which mutant huntingtin protein (mHTT) causes HD is complex and poorly understood but leads to cell death, in particular in striatal neurons. In clinical trials antioxidants (e.g. coenzyme Q10), selisistat, PBT2, cysteamine, N-methyl-D-aspartate (NMDA)-receptor antagonists and tyrosine kinase B receptor agonists have been studied in HD. CONCLUSION No disease-modifying therapy is currently available for HD; however, gene silencing, e.g. through RNA interference, is a promising technique which could lead to effective therapies in due course.
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Affiliation(s)
- J D Rollnik
- Institut für neurorehabilitative Forschung (InFo) der BDH-Klinik Hessisch Oldendorf gGmbH, Assoziiertes Institut der Medizinischen Hochschule Hannover (MHH), Greitstr. 18-28, 31840, Hessisch Oldendorf, Deutschland,
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58
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Bates GP, Dorsey R, Gusella JF, Hayden MR, Kay C, Leavitt BR, Nance M, Ross CA, Scahill RI, Wetzel R, Wild EJ, Tabrizi SJ. Huntington disease. Nat Rev Dis Primers 2015; 1:15005. [PMID: 27188817 DOI: 10.1038/nrdp.2015.5] [Citation(s) in RCA: 901] [Impact Index Per Article: 100.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Huntington disease is devastating to patients and their families - with autosomal dominant inheritance, onset typically in the prime of adult life, progressive course, and a combination of motor, cognitive and behavioural features. The disease is caused by an expanded CAG trinucleotide repeat (of variable length) in HTT, the gene that encodes the protein huntingtin. In mutation carriers, huntingtin is produced with abnormally long polyglutamine sequences that confer toxic gains of function and predispose the protein to fragmentation, resulting in neuronal dysfunction and death. In this Primer, we review the epidemiology of Huntington disease, noting that prevalence is higher than previously thought, geographically variable and increasing. We describe the relationship between CAG repeat length and clinical phenotype, as well as the concept of genetic modifiers of the disease. We discuss normal huntingtin protein function, evidence for differential toxicity of mutant huntingtin variants, theories of huntingtin aggregation and the many different mechanisms of Huntington disease pathogenesis. We describe the genetic and clinical diagnosis of the condition, its clinical assessment and the multidisciplinary management of symptoms, given the absence of effective disease-modifying therapies. We review past and present clinical trials and therapeutic strategies under investigation, including impending trials of targeted huntingtin-lowering drugs and the progress in development of biomarkers that will support the next generation of trials. For an illustrated summary of this Primer, visit: http://go.nature.com/hPMENh.
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Affiliation(s)
- Gillian P Bates
- Department of Medical and Molecular Genetics, King's College London, London, UK
| | - Ray Dorsey
- Department of Neurology, University of Rochester Medical Center, Rochester, New York, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Martha Nance
- Struthers Parkinson's Center, Golden Valley, Minneapolis, Minnesota, USA; and Hennepin County Medical Center, Minneapolis, Minnesota, USA
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry and Departments of Neurology, Pharmacology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rachael I Scahill
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ronald Wetzel
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Edward J Wild
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
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59
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The neuroprotection of repetitive transcranial magnetic stimulation pre-treatment in vascular dementia rats. J Mol Neurosci 2015; 56:198-204. [PMID: 25585610 DOI: 10.1007/s12031-014-0480-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 09/01/2014] [Indexed: 10/24/2022]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique that could interfere cortical excitability though brief electric currents induced by alternating magnetic fields from the inductive coil. Currently, it has been applied in many fields of basic and clinical neuro-research. The aims of the present study are to investigate the effect of rTMS pre-treatment on cognitive function in vascular dementia (VaD) rats and further explore the molecular mechanism of rTMS neuroprotection on VaD. We found that rTMS pre-treated VaD rats showed significantly better memory and learning abilities in Morris water maze test compared to the untreated group. Moreover, the mRNA and protein expression levels of BDNF, TrkB, and SYN were significantly higher in the rTMS pre-treated group, indicating that rTMS pre-treatment has neuroprotective effect for VaD, which may have resulted from the increased level of BDNF, TrkB, and SYN in the hippocampal CA1 area.
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60
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Fink KD, Deng P, Torrest A, Stewart H, Pollock K, Gruenloh W, Annett G, Tempkin T, Wheelock V, Nolta JA. Developing stem cell therapies for juvenile and adult-onset Huntington's disease. Regen Med 2015; 10:623-46. [PMID: 26237705 PMCID: PMC6785015 DOI: 10.2217/rme.15.25] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Stem cell therapies have been explored as a new avenue for the treatment of neurologic disease and damage within the CNS in part due to their native ability to mimic repair mechanisms in the brain. Mesenchymal stem cells have been of particular clinical interest due to their ability to release beneficial neurotrophic factors and their ability to foster a neuroprotective microenviroment. While early stem cell transplantation therapies have been fraught with technical and political concerns as well as limited clinical benefits, mesenchymal stem cell therapies have been shown to be clinically beneficial and derivable from nonembryonic, adult sources. The focus of this review will be on emerging and extant stem cell therapies for juvenile and adult-onset Huntington's disease.
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Affiliation(s)
- Kyle D Fink
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - Peter Deng
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
- GenomeCenter, Biochemistry & Molecular Medicine, University of California, 451 Health Sciences Dr. Davis, CA 95616, USA
| | - Audrey Torrest
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - Heather Stewart
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - Kari Pollock
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - William Gruenloh
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - Geralyn Annett
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
| | - Teresa Tempkin
- Department of Neurology, University of California Davis Health Systems, 4860 Y Street Sacramento, CA 95817, USA
| | - Vicki Wheelock
- Department of Neurology, University of California Davis Health Systems, 4860 Y Street Sacramento, CA 95817, USA
| | - Jan A Nolta
- Stem Cell Program & Institute for Regenerative Cures, University of California Davis Health Systems, 2921 Stockton Blvd. Sacramento, CA 95817, USA
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61
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Plotkin JL, Surmeier DJ. Impaired striatal function in Huntington's disease is due to aberrant p75NTR signaling. ACTA ACUST UNITED AC 2014; 2:e968482. [PMID: 26942104 PMCID: PMC4755240 DOI: 10.4161/2167549x.2014.968482] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 09/18/2014] [Indexed: 11/20/2022]
Abstract
Huntington's disease (HD) is a rare genetic neurodegenerative disorder for which there is currently no cure. Early hyperkinetic motor symptoms are consistent with reduced activity of indirect pathway striatal projection neurons (iSPNs) responsible for suppression of unwanted actions. Our recent work suggests that one of the factors contributing to this deficit is impaired brain-derived neurotrophic factor (BDNF) signaling that regulates the strength of iSPN excitatory synapses. Specifically, we found that BDNF-dependent corticostriatal synaptic long-term potentiation (LTP) was lost in iSPNs from 2 genetic models of HD, just as they began to robustly manifest motor symptoms. This deficit was not attributable to problems in BDNF production, delivery or receptor binding. Rather, the plasticity deficit stemmed from enhanced signaling through p75 neurotrophin receptors (p75NTRs) and the phosphatase and tensin homolog (PTEN), leading to antagonism of intracellular TrkBR cascades and LTP. This study suggests HD therapeutics should target p75NTR signaling, not TrkBR.
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Affiliation(s)
- Joshua L Plotkin
- Department of Physiology; Feinberg School of Medicine ; Northwestern University ; Chicago, IL USA
| | - D James Surmeier
- Department of Physiology; Feinberg School of Medicine ; Northwestern University ; Chicago, IL USA
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62
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Numakawa T. Possible protective action of neurotrophic factors and natural compounds against common neurodegenerative diseases. Neural Regen Res 2014; 9:1506-8. [PMID: 25317165 PMCID: PMC4192965 DOI: 10.4103/1673-5374.139474] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2014] [Indexed: 02/01/2023] Open
Abstract
It has been suggested that altered levels/function of brain-derived neurotrophic factor (BDNF) play a role in the pathophysiology of neurodegenerative diseases including Alzheimer's disease. BDNF positively contributes to neural survival and synapse maintenance via stimulating its high affinity receptor TrkB, making upregulation of BDNF and/or activation of BDNF-related intracellular signaling an attractive approach to treating neurodegenerative diseases. In this short review, I briefly introduce small natural compounds such as flavonoids that successfully increase activation of the BDNF system and discuss their beneficial effects against neurodegeneration.
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Affiliation(s)
- Tadahiro Numakawa
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo, Japan
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63
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Wild EJ, Tabrizi SJ. Targets for future clinical trials in Huntington's disease: what's in the pipeline? Mov Disord 2014; 29:1434-45. [PMID: 25155142 PMCID: PMC4265300 DOI: 10.1002/mds.26007] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 01/08/2023] Open
Abstract
The known genetic cause of Huntington's disease (HD) has fueled considerable progress in understanding its pathobiology and the development of therapeutic approaches aimed at correcting specific changes linked to the causative mutation. Among the most promising is reducing expression of mutant huntingtin protein (mHTT) with RNA interference or antisense oligonucleotides; human trials are now being planned. Zinc-finger transcriptional repression is another innovative method to reduce mHTT expression. Modulation of mHTT phosphorylation, chaperone upregulation, and autophagy enhancement represent attempts to alter cellular homeostasis to favor removal of mHTT. Inhibition of histone deacetylases (HDACs) remains of interest; recent work affirms HDAC4 as a target but questions the assumed centrality of its catalytic activity in HD. Phosphodiesterase inhibition, aimed at restoring synaptic function, has progressed rapidly to human trials. Deranged cellular signaling provides several tractable targets, but specificity and complexity are challenges. Restoring neurotrophic support in HD remains a key potential therapeutic approach. with several approaches being pursued, including brain-derived neurotrophic factor (BDNF) mimesis through tyrosine receptor kinase B (TrkB) agonism and monoclonal antibodies. An increasing understanding of the role of glial cells in HD has led to several new therapeutic avenues, including kynurenine monooxygenase inhibition, immunomodulation by laquinimod, CB2 agonism, and others. The complex metabolic derangements in HD remain under study, but no clear therapeutic strategy has yet emerged. We conclude that many exciting therapeutics are progressing through the development pipeline, and combining a better understanding of HD biology in human patients, with concerted medicinal chemistry efforts, will be crucial for bringing about an era of effective therapies.
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Affiliation(s)
- Edward J Wild
- Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology & NeurosurgeryQueen Square, London, WC1N 3BG, UK
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology & NeurosurgeryQueen Square, London, WC1N 3BG, UK
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64
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Lee CF, Chern Y. Adenosine receptors and Huntington's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 119:195-232. [PMID: 25175968 DOI: 10.1016/b978-0-12-801022-8.00010-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Adenosine regulates important pathophysiological functions via four distinct adenosine receptor subtypes (A1, A2A, A2B, and A3). The A1 and A2A adenosine receptors (A1R and A2AR) are major targets of caffeine and have been extensively investigated. Huntington's disease (HD) is a dominant neurodegenerative disease caused by an abnormal CAG expansion in the Huntingtin gene. Since the first genetic HD model was created almost two decades ago, tremendous progress regarding the function of the adenosine receptors in HD has been made. Chronic intake of caffeine was recently shown to be positively associated with the disease onset of HD. Moreover, genetic polymorphism of A2AR is believed to impact the age of onset. Given the importance of adenosine receptors as drug targets for human diseases, this review highlights the recent findings that delineate the roles of adenosine receptors in HD and discusses their potential for serving as drug targets and/or biomarkers for HD. Adenosine is a purine nucleoside that regulates important physiological functions via four different adenosine receptors (A1, A2A, A2B, and A3). These adenosine receptors have seven transmembrane domains and belong to the G protein-coupled receptor family. The functions of the A1 adenosine receptor (A1R) and A2A adenosine receptor (A2AR) have been investigated relative to HD. In this review, we summarize the recent findings regarding the role of adenosine receptors in HD and discuss the potential application of adenosine receptors as drug targets and biomarkers for HD.
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Affiliation(s)
- Chien-fei Lee
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yijuang Chern
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
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