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Lázaro DF, Lee VMY. Navigating through the complexities of synucleinopathies: Insights into pathogenesis, heterogeneity, and future perspectives. Neuron 2024:S0896-6273(24)00364-7. [PMID: 38861985 DOI: 10.1016/j.neuron.2024.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/22/2024] [Accepted: 05/14/2024] [Indexed: 06/13/2024]
Abstract
The aggregation of alpha-synuclein (aSyn) represents a neuropathological hallmark observed in a group of neurodegenerative disorders collectively known as synucleinopathies. Despite their shared characteristics, these disorders manifest diverse clinical and pathological phenotypes. The mechanism underlying this heterogeneity is thought to be due to the diversity in the aSyn strains present across the diseases. In this perspective, we will explore recent findings on aSyn strains and discuss recent discoveries about Lewy bodies' composition. We further discuss the current hypothesis for aSyn spreading and emphasize the emerging biomarker field demonstrating promising results. A comprehension of these mechanisms holds substantial promise for future clinical applications. This understanding can pave the way for the development of personalized medicine strategies, specifically targeting the unique underlying causes of each synucleinopathy. Such advancements can revolutionize therapeutic approaches and significantly contribute to more effective interventions in the intricate landscape of neurodegenerative disorders.
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Affiliation(s)
- Diana F Lázaro
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Medicine, University of Pennsylvania, Perelman School of Medicine at University of Pennsylvania, 3600 Spruce Street, 3 Maloney Building, Philadelphia, PA 19104, USA.
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Medicine, University of Pennsylvania, Perelman School of Medicine at University of Pennsylvania, 3600 Spruce Street, 3 Maloney Building, Philadelphia, PA 19104, USA.
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2
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Niu J, Zhong Y, Jin C, Cen P, Wang J, Cui C, Xue L, Cui X, Tian M, Zhang H. Positron Emission Tomography Imaging of Synaptic Dysfunction in Parkinson's Disease. Neurosci Bull 2024; 40:743-758. [PMID: 38483697 PMCID: PMC11178751 DOI: 10.1007/s12264-024-01188-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/09/2023] [Indexed: 06/15/2024] Open
Abstract
Parkinson's disease (PD) is one of the most common neurodegenerative diseases with a complex pathogenesis. Aggregations formed by abnormal deposition of alpha-synuclein (αSyn) lead to synapse dysfunction of the dopamine and non-dopamine systems. The loss of dopaminergic neurons and concomitant alterations in non-dopaminergic function in PD constitute its primary pathological manifestation. Positron emission tomography (PET), as a representative molecular imaging technique, enables the non-invasive visualization, characterization, and quantification of biological processes at cellular and molecular levels. Imaging synaptic function with PET would provide insights into the mechanisms underlying PD and facilitate the optimization of clinical management. In this review, we focus on the synaptic dysfunction associated with the αSyn pathology of PD, summarize various related targets and radiopharmaceuticals, and discuss applications and perspectives of PET imaging of synaptic dysfunction in PD.
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Affiliation(s)
- Jiaqi Niu
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Yan Zhong
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Chentao Jin
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Peili Cen
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Jing Wang
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Chunyi Cui
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Le Xue
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Xingyue Cui
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China
| | - Mei Tian
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China.
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China.
- Huashan Hospital and Human Phenome Institute, Fudan University, Shanghai, 200040, China.
| | - Hong Zhang
- Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
- Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, 310009, China.
- Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, 310009, China.
- College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, 310014, China.
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, 310014, China.
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Brazdis RM, von Zimmermann C, Lenz B, Kornhuber J, Mühle C. Peripheral Upregulation of Parkinson's Disease-Associated Genes Encoding α-Synuclein, β-Glucocerebrosidase, and Ceramide Glucosyltransferase in Major Depression. Int J Mol Sci 2024; 25:3219. [PMID: 38542193 PMCID: PMC10970259 DOI: 10.3390/ijms25063219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 04/04/2024] Open
Abstract
Due to the high comorbidity of Parkinson's disease (PD) with major depressive disorder (MDD) and the involvement of sphingolipids in both conditions, we investigated the peripheral expression levels of three primarily PD-associated genes: α-synuclein (SNCA), lysosomal enzyme β-glucocerebrosidase (GBA1), and UDP-glucose ceramide glucosyltransferase (UGCG) in a sex-balanced MDD cohort. Normalized gene expression was determined by quantitative PCR in patients suffering from MDD (unmedicated n = 63, medicated n = 66) and controls (remitted MDD n = 39, healthy subjects n = 61). We observed that expression levels of SNCA (p = 0.036), GBA1 (p = 0.014), and UGCG (p = 0.0002) were higher in currently depressed patients compared to controls and remitted patients, and expression of GBA1 and UGCG decreased in medicated patients during three weeks of therapy. Additionally, in subgroups, expression was positively correlated with the severity of depression and anxiety. Furthermore, we identified correlations between the gene expression levels and PD-related laboratory parameters. Our findings suggest that SNCA, GBA1, and UGCG analysis could be instrumental in the search for biomarkers of MDD and in understanding the overlapping pathological mechanisms underlying neuro-psychiatric diseases.
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Affiliation(s)
- Razvan-Marius Brazdis
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen and Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (R.-M.B.); (B.L.); (J.K.)
| | - Claudia von Zimmermann
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen and Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (R.-M.B.); (B.L.); (J.K.)
| | - Bernd Lenz
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen and Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (R.-M.B.); (B.L.); (J.K.)
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health (CIMH), Medical Faculty Mannheim, Heidelberg University, 68159 Mannheim, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen and Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (R.-M.B.); (B.L.); (J.K.)
| | - Christiane Mühle
- Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen and Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (R.-M.B.); (B.L.); (J.K.)
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4
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Nordengen K, Morland C. From Synaptic Physiology to Synaptic Pathology: The Enigma of α-Synuclein. Int J Mol Sci 2024; 25:986. [PMID: 38256059 PMCID: PMC10815905 DOI: 10.3390/ijms25020986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Alpha-synuclein (α-syn) has gained significant attention due to its involvement in neurodegenerative diseases, particularly Parkinson's disease. However, its normal function in the human brain is equally fascinating. The α-syn protein is highly dynamic and can adapt to various conformational stages, which differ in their interaction with synaptic elements, their propensity to drive pathological aggregation, and their toxicity. This review will delve into the multifaceted role of α-syn in different types of synapses, shedding light on contributions to neurotransmission and overall brain function. We describe the physiological role of α-syn at central synapses, including the bidirectional interaction between α-syn and neurotransmitter systems.
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Affiliation(s)
- Kaja Nordengen
- Department of Neurology, Oslo University Hospital, 0424 Oslo, Norway
| | - Cecilie Morland
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, The Faculty of Mathematics and Natural Sciences, University of Oslo, 1068 Oslo, Norway
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The Role of α-Synuclein in the Regulation of Serotonin System: Physiological and Pathological Features. Biomedicines 2023; 11:biomedicines11020541. [PMID: 36831077 PMCID: PMC9953742 DOI: 10.3390/biomedicines11020541] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/30/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
In patients affected by Parkinson's disease (PD), up to 50% of them experience cognitive changes, and psychiatric disturbances, such as anxiety and depression, often precede the onset of motor symptoms and have a negative impact on their quality of life. Pathologically, PD is characterized by the loss of dopamine (DA) neurons in the substantia nigra pars compacta (SNc) and the presence of intracellular inclusions, called Lewy bodies and Lewy neurites, composed mostly of α-synuclein (α-Syn). Much of PD research has focused on the role of α-Syn aggregates in the degeneration of SNc DA neurons due to the impact of striatal DA deficits on classical motor phenotypes. However, abundant Lewy pathology is also found in other brain regions including the midbrain raphe nuclei, which may contribute to non-motor symptoms. Indeed, dysfunction of the serotonergic (5-HT) system, which regulates mood and emotional pathways, occurs during the premotor phase of PD. However, little is known about the functional consequences of α-Syn inclusions in this neuronal population other than DA neurons. Here, we provide an overview of the current knowledge of α-Syn and its role in regulating the 5-HT function in health and disease. Understanding the relative contributions to α-Syn-linked alterations in the 5-HT system may provide a basis for identifying PD patients at risk for developing depression and could lead to a more targeted therapeutic approach.
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6
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Caligiore D, Giocondo F, Silvetti M. The Neurodegenerative Elderly Syndrome (NES) hypothesis: Alzheimer and Parkinson are two faces of the same disease. IBRO Neurosci Rep 2022; 13:330-343. [PMID: 36247524 PMCID: PMC9554826 DOI: 10.1016/j.ibneur.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 09/07/2022] [Accepted: 09/21/2022] [Indexed: 11/25/2022] Open
Abstract
Increasing evidence suggests that Alzheimer's disease (AD) and Parkinson's disease (PD) share monoamine and alpha-synuclein (αSyn) dysfunctions, often beginning years before clinical manifestations onset. The triggers for these impairments and the causes leading these early neurodegenerative processes to become AD or PD remain unclear. We address these issues by proposing a radically new perspective to frame AD and PD: they are different manifestations of one only disease we call "Neurodegenerative Elderly Syndrome (NES)". NES goes through three phases. The seeding stage, which starts years before clinical signs, and where the part of the brain-body affected by the initial αSyn and monoamine dysfunctions, influences the future possible progression of NES towards PD or AD. The compensatory stage, where the clinical symptoms are still silent thanks to compensatory mechanisms keeping monoamine concentrations homeostasis. The bifurcation stage, where NES becomes AD or PD. We present recent literature supporting NES and discuss how this hypothesis could radically change the comprehension of AD and PD comorbidities and the design of novel system-level diagnostic and therapeutic actions.
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Affiliation(s)
- Daniele Caligiore
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, Rome 00185, Italy
- AI2Life s.r.l., Innovative Start-Up, ISTC-CNR Spin-Off, Via Sebino 32, Rome 00199, Italy
| | - Flora Giocondo
- Laboratory of Embodied Natural and Artificial Intelligence, Institute of Cognitive Sciences and Technologies, National Research Council (LENAI-ISTC-CNR), Via San Martino della Battaglia 44, Rome 00185, Italy
| | - Massimo Silvetti
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, Rome 00185, Italy
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Kulkarni AS, Burns MR, Brundin P, Wesson DW. Linking α-synuclein-induced synaptopathy and neural network dysfunction in early Parkinson's disease. Brain Commun 2022; 4:fcac165. [PMID: 35822101 PMCID: PMC9272065 DOI: 10.1093/braincomms/fcac165] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/11/2022] [Accepted: 06/20/2022] [Indexed: 01/18/2023] Open
Abstract
The prodromal phase of Parkinson's disease is characterized by aggregation of the misfolded pathogenic protein α-synuclein in select neural centres, co-occurring with non-motor symptoms including sensory and cognitive loss, and emotional disturbances. It is unclear whether neuronal loss is significant during the prodrome. Underlying these symptoms are synaptic impairments and aberrant neural network activity. However, the relationships between synaptic defects and network-level perturbations are not established. In experimental models, pathological α-synuclein not only impacts neurotransmission at the synaptic level, but also leads to changes in brain network-level oscillatory dynamics-both of which likely contribute to non-motor deficits observed in Parkinson's disease. Here we draw upon research from both human subjects and experimental models to propose a 'synapse to network prodrome cascade' wherein before overt cell death, pathological α-synuclein induces synaptic loss and contributes to aberrant network activity, which then gives rise to prodromal symptomology. As the disease progresses, abnormal patterns of neural activity ultimately lead to neuronal loss and clinical progression of disease. Finally, we outline goals and research needed to unravel the basis of functional impairments in Parkinson's disease and other α-synucleinopathies.
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Affiliation(s)
- Aishwarya S Kulkarni
- Department of Pharmacology & Therapeutics, University of Florida, 1200 Newell Dr, Gainesville, FL 32610, USA
| | - Matthew R Burns
- Department of Neurology, University of Florida, 1200 Newell Dr, Gainesville, FL 32610, USA
- Norman Fixel Institute for Neurological Disorders, University of Florida, 1200 Newell Dr, Gainesville, FL 32610, USA
| | - Patrik Brundin
- Pharma Research and Early Development (pRED), F. Hoffman-La Roche, Little Falls, NJ, USA
| | - Daniel W Wesson
- Department of Pharmacology & Therapeutics, University of Florida, 1200 Newell Dr, Gainesville, FL 32610, USA
- Norman Fixel Institute for Neurological Disorders, University of Florida, 1200 Newell Dr, Gainesville, FL 32610, USA
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8
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Weerasinghe-Mudiyanselage PDE, Ang MJ, Kang S, Kim JS, Moon C. Structural Plasticity of the Hippocampus in Neurodegenerative Diseases. Int J Mol Sci 2022; 23:3349. [PMID: 35328770 PMCID: PMC8955928 DOI: 10.3390/ijms23063349] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/10/2022] Open
Abstract
Neuroplasticity is the capacity of neural networks in the brain to alter through development and rearrangement. It can be classified as structural and functional plasticity. The hippocampus is more susceptible to neuroplasticity as compared to other brain regions. Structural modifications in the hippocampus underpin several neurodegenerative diseases that exhibit cognitive and emotional dysregulation. This article reviews the findings of several preclinical and clinical studies about the role of structural plasticity in the hippocampus in neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. In this study, literature was surveyed using Google Scholar, PubMed, Web of Science, and Scopus, to review the mechanisms that underlie the alterations in the structural plasticity of the hippocampus in neurodegenerative diseases. This review summarizes the role of structural plasticity in the hippocampus for the etiopathogenesis of neurodegenerative diseases and identifies the current focus and gaps in knowledge about hippocampal dysfunctions. Ultimately, this information will be useful to propel future mechanistic and therapeutic research in neurodegenerative diseases.
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Affiliation(s)
- Poornima D. E. Weerasinghe-Mudiyanselage
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; (P.D.E.W.-M.); (M.J.A.); (S.K.); (J.-S.K.)
| | - Mary Jasmin Ang
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; (P.D.E.W.-M.); (M.J.A.); (S.K.); (J.-S.K.)
- College of Veterinary Medicine, University of the Philippines Los Baños, Los Baños 4031, Philippines
| | - Sohi Kang
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; (P.D.E.W.-M.); (M.J.A.); (S.K.); (J.-S.K.)
| | - Joong-Sun Kim
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; (P.D.E.W.-M.); (M.J.A.); (S.K.); (J.-S.K.)
| | - Changjong Moon
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; (P.D.E.W.-M.); (M.J.A.); (S.K.); (J.-S.K.)
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Jellen LC, Lewis MM, Du G, Wang X, Galvis MLE, Krzyzanowski S, Capan CD, Snyder AM, Connor JR, Kong L, Mailman RB, Brundin P, Brundin L, Huang X. Low plasma serotonin linked to higher nigral iron in Parkinson's disease. Sci Rep 2021; 11:24384. [PMID: 34934078 PMCID: PMC8692322 DOI: 10.1038/s41598-021-03700-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/18/2021] [Indexed: 12/30/2022] Open
Abstract
A growing body of evidence suggests nigral iron accumulation plays an important role in the pathophysiology of Parkinson's disease (PD), contributing to dopaminergic neuron loss in the substantia nigra pars compacta (SNc). Converging evidence suggests this accumulation might be related to, or increased by, serotonergic dysfunction, a common, often early feature of the disease. We investigated whether lower plasma serotonin in PD is associated with higher nigral iron. We obtained plasma samples from 97 PD patients and 89 controls and MRI scans from a sub-cohort (62 PD, 70 controls). We measured serotonin concentrations using ultra-high performance liquid chromatography and regional iron content using MRI-based quantitative susceptibility mapping. PD patients had lower plasma serotonin (p < 0.0001) and higher nigral iron content (SNc: p < 0.001) overall. Exclusively in PD, lower plasma serotonin was correlated with higher nigral iron (SNc: r(58) = - 0.501, p < 0.001). This correlation was significant even in patients newly diagnosed (< 1 year) and stronger in the SNc than any other region examined. This study reveals an early, linear association between low serotonin and higher nigral iron in PD patients, which is absent in controls. This is consistent with a serotonin-iron relationship in the disease process, warranting further studies to determine its cause and directionality.
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Affiliation(s)
- Leslie C Jellen
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Mechelle M Lewis
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
- Department of Pharmacology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Guangwei Du
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Xi Wang
- Public Health Sciences, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Martha L Escobar Galvis
- Parkinson's Disease Center, Department of Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave NE, Grand Rapids, MI, 49503, USA
| | - Stanislaw Krzyzanowski
- Parkinson's Disease Center, Department of Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave NE, Grand Rapids, MI, 49503, USA
| | - Colt D Capan
- Parkinson's Disease Center, Department of Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave NE, Grand Rapids, MI, 49503, USA
| | - Amanda M Snyder
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - James R Connor
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Lan Kong
- Public Health Sciences, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Richard B Mailman
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
- Department of Pharmacology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Patrik Brundin
- Parkinson's Disease Center, Department of Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave NE, Grand Rapids, MI, 49503, USA
| | - Lena Brundin
- Parkinson's Disease Center, Department of Neurodegenerative Science, Van Andel Institute, 333 Bostwick Ave NE, Grand Rapids, MI, 49503, USA.
- Division of Psychiatry and Behavioral Medicine, Michigan State University College of Human Medicine, Grand Rapids, MI, USA.
| | - Xuemei Huang
- Department of Neurology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA.
- Department of Pharmacology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA.
- Departments of Neurosurgery and Radiology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA.
- Department of Kinesiology, Penn State University-Milton S. Hershey Medical Center, Hershey, PA, USA.
- Translational Brain Research Center, Penn State University-Hershey Medical Center, 500 University Dr., Mail Code H037, Hershey, PA, 17033, USA.
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10
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Huntington TE, Srinivasan R. Adeno-Associated Virus Expression of α-Synuclein as a Tool to Model Parkinson's Disease: Current Understanding and Knowledge Gaps. Aging Dis 2021; 12:1120-1137. [PMID: 34221553 PMCID: PMC8219504 DOI: 10.14336/ad.2021.0517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/16/2021] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder in the aging population and is characterized by a constellation of motor and non-motor symptoms. The abnormal aggregation and spread of alpha-synuclein (α-syn) is thought to underlie the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc), leading to the development of PD. It is in this context that the use of adeno-associated viruses (AAVs) to express a-syn in the rodent midbrain has become a popular tool to model SNc DA neuron loss during PD. In this review, we summarize results from two decades of experiments using AAV-mediated a-syn expression in rodents to model PD. Specifically, we outline aspects of AAV vectors that are particularly relevant to modeling a-syn dysfunction in rodent models of PD such as changes in striatal neurochemistry, a-syn biochemistry, and PD-related behaviors resulting from AAV-mediated a-syn expression in the midbrain. Finally, we discuss the emerging role of astrocytes in propagating a-syn pathology, and point to future directions for employing AAVs as a tool to better understand how astrocytes contribute to a-syn pathology during the development of PD. We envision that lessons learned from two decades of utilizing AAVs to express a-syn in the rodent brain will enable us to develop an optimized set of parameters for gaining a better understanding of how a-syn leads to the development of PD.
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Affiliation(s)
- Taylor E Huntington
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University College of Medicine, 8447 Riverside Pkwy, Bryan, TX 77807, USA.
- Texas A&M Institute for Neuroscience (TAMIN), College Station, TX 77843, USA
| | - Rahul Srinivasan
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University College of Medicine, 8447 Riverside Pkwy, Bryan, TX 77807, USA.
- Texas A&M Institute for Neuroscience (TAMIN), College Station, TX 77843, USA
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11
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Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
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Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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12
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Hadi F, Akrami H, Totonchi M, Barzegar A, Nabavi SM, Shahpasand K. α-synuclein abnormalities trigger focal tau pathology, spreading to various brain areas in Parkinson disease. J Neurochem 2021; 157:727-751. [PMID: 33264426 DOI: 10.1111/jnc.15257] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/28/2020] [Accepted: 11/30/2020] [Indexed: 12/21/2022]
Abstract
Parkinson disease (PD) is the second most common neurodegenerative disorder, whose prevalence is 2~3% in the population over 65. α-Synuclein aggregation is the major pathological hallmark of PD. However, recent studies have demonstrated enhancing evidence of tau pathology in PD. Despite extensive considerations, thus far, the actual spreading mechanism of neurodegeneration has remained elusive in a PD brain. This study aimed to further investigate the development of α-synuclein and tau pathology. We employed various PD models, including cultured neurons treated with either 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or with recombinant α-synuclein. Also, we studied dopaminergic neurons of cytokine Interferon-β knock-out. Moreover, we examined rats treated with 6-hydroxydopamine, Rhesus monkeys administrated with MPTP neurotoxin, and finally, human post-mortem brains. We found the α-synuclein phosphorylation triggers tau pathogenicity. Also, we observed more widespread phosphorylated tau than α-synuclein with prion-like nature in various brain areas. We optionally removed P-tau or P-α-synuclein from cytokine interferon-β knock out with respective monoclonal antibodies. We found that tau immunotherapy suppressed neurodegeneration more than α-synuclein elimination. Our findings indicate that the pathogenic tau could be one of the leading causes of comprehensive neurodegeneration triggered by PD. Thus, we can propose an efficient therapeutic target to fight the devastating disorder.
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Affiliation(s)
- Fatemeh Hadi
- Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran
| | - Hassan Akrami
- Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran
| | - Mehdi Totonchi
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute, ACECR, Tehran, Iran
| | | | - Seyed Massood Nabavi
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute, ACECR, Tehran, Iran
| | - Koorosh Shahpasand
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute, ACECR, Tehran, Iran
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13
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Novel PET Biomarkers to Disentangle Molecular Pathways across Age-Related Neurodegenerative Diseases. Cells 2020; 9:cells9122581. [PMID: 33276490 PMCID: PMC7761606 DOI: 10.3390/cells9122581] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/25/2020] [Accepted: 11/28/2020] [Indexed: 12/11/2022] Open
Abstract
There is a need to disentangle the etiological puzzle of age-related neurodegenerative diseases, whose clinical phenotypes arise from known, and as yet unknown, pathways that can act distinctly or in concert. Enhanced sub-phenotyping and the identification of in vivo biomarker-driven signature profiles could improve the stratification of patients into clinical trials and, potentially, help to drive the treatment landscape towards the precision medicine paradigm. The rapidly growing field of neuroimaging offers valuable tools to investigate disease pathophysiology and molecular pathways in humans, with the potential to capture the whole disease course starting from preclinical stages. Positron emission tomography (PET) combines the advantages of a versatile imaging technique with the ability to quantify, to nanomolar sensitivity, molecular targets in vivo. This review will discuss current research and available imaging biomarkers evaluating dysregulation of the main molecular pathways across age-related neurodegenerative diseases. The molecular pathways focused on in this review involve mitochondrial dysfunction and energy dysregulation; neuroinflammation; protein misfolding; aggregation and the concepts of pathobiology, synaptic dysfunction, neurotransmitter dysregulation and dysfunction of the glymphatic system. The use of PET imaging to dissect these molecular pathways and the potential to aid sub-phenotyping will be discussed, with a focus on novel PET biomarkers.
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14
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SNCA Rep1 microsatellite length influences non-motor symptoms in early Parkinson's disease. Aging (Albany NY) 2020; 12:20880-20887. [PMID: 33082300 PMCID: PMC7655210 DOI: 10.18632/aging.104111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/09/2020] [Indexed: 11/25/2022]
Abstract
Long alpha-synuclein gene (SNCA) promoter (Rep1) allele-carriers are linked to higher risk for Parkinson's disease (PD) and faster motor progression. Non-motor symptoms including autonomic, neuropsychiatric, and sleep disorders are common in PD. However, the relationship between SNCA Rep1 microsatellite lengths and non-motor symptoms in early PD remains to be elucidated. 171 consecutive early PD patients were recruited from tertiary clinics and genotyped for Rep1. Multivariable regression analyses were performed to examine associations between Rep1 alleles and non-motor outcome scores. Longer Rep1 alleles significantly associated with higher total Non-Motor Symptom Scale (NMSS) scores (p=.006) and Hospital Anxiety and Depression Scale (HADS) depression subscale scores (p=.002), after adjusting for covariates and Bonferroni correction. We demonstrated that SNCA Rep1 allele length influences overall non-motor symptom burden and depression in early PD patients. Further functional studies to evaluate the role of Rep1 in non-dopaminergic systems may unravel new therapeutic targets for non-motor symptoms in PD.
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Fouka M, Mavroeidi P, Tsaka G, Xilouri M. In Search of Effective Treatments Targeting α-Synuclein Toxicity in Synucleinopathies: Pros and Cons. Front Cell Dev Biol 2020; 8:559791. [PMID: 33015057 PMCID: PMC7500083 DOI: 10.3389/fcell.2020.559791] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/14/2020] [Indexed: 12/11/2022] Open
Abstract
Parkinson's disease (PD), multiple system atrophy (MSA) and Dementia with Lewy bodies (DLB) represent pathologically similar, progressive neurodegenerative disorders characterized by the pathological aggregation of the neuronal protein α-synuclein. PD and DLB are characterized by the abnormal accumulation and aggregation of α-synuclein in proteinaceous inclusions within neurons named Lewy bodies (LBs) and Lewy neurites (LNs), whereas in MSA α-synuclein inclusions are mainly detected within oligodendrocytes named glial cytoplasmic inclusions (GCIs). The presence of pathologically aggregated α-synuclein along with components of the protein degradation machinery, such as ubiquitin and p62, in LBs and GCIs is considered to underlie the pathogenic cascade that eventually leads to the severe neurodegeneration and neuroinflammation that characterizes these diseases. Importantly, α-synuclein is proposed to undergo pathogenic misfolding and oligomerization into higher-order structures, revealing self-templating conformations, and to exert the ability of "prion-like" spreading between cells. Therefore, the manner in which the protein is produced, is modified within neural cells and is degraded, represents a major focus of current research efforts in the field. Given that α-synuclein protein load is critical to disease pathogenesis, the identification of means to limit intracellular protein burden and halt α-synuclein propagation represents an obvious therapeutic approach in synucleinopathies. However, up to date the development of effective therapeutic strategies to prevent degeneration in synucleinopathies is limited, due to the lack of knowledge regarding the precise mechanisms underlying the observed pathology. This review critically summarizes the recent developed strategies to counteract α-synuclein toxicity, including those aimed to increase protein degradation, to prevent protein aggregation and cell-to-cell propagation, or to engage antibodies against α-synuclein and discuss open questions and unknowns for future therapeutic approaches.
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Affiliation(s)
| | | | | | - Maria Xilouri
- Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
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The Role of Alpha-Synuclein and Other Parkinson's Genes in Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:ijms21165724. [PMID: 32785033 PMCID: PMC7460874 DOI: 10.3390/ijms21165724] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/29/2020] [Accepted: 08/08/2020] [Indexed: 12/13/2022] Open
Abstract
Neurodevelopmental and late-onset neurodegenerative disorders present as separate entities that are clinically and neuropathologically quite distinct. However, recent evidence has highlighted surprising commonalities and converging features at the clinical, genomic, and molecular level between these two disease spectra. This is particularly striking in the context of autism spectrum disorder (ASD) and Parkinson's disease (PD). Genetic causes and risk factors play a central role in disease pathophysiology and enable the identification of overlapping mechanisms and pathways. Here, we focus on clinico-genetic studies of causal variants and overlapping clinical and cellular features of ASD and PD. Several genes and genomic regions were selected for our review, including SNCA (alpha-synuclein), PARK2 (parkin RBR E3 ubiquitin protein ligase), chromosome 22q11 deletion/DiGeorge region, and FMR1 (fragile X mental retardation 1) repeat expansion, which influence the development of both ASD and PD, with converging features related to synaptic function and neurogenesis. Both PD and ASD display alterations and impairments at the synaptic level, representing early and key disease phenotypes, which support the hypothesis of converging mechanisms between the two types of diseases. Therefore, understanding the underlying molecular mechanisms might inform on common targets and therapeutic approaches. We propose to re-conceptualize how we understand these disorders and provide a new angle into disease targets and mechanisms linking neurodevelopmental disorders and neurodegeneration.
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17
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Advances in modelling alpha-synuclein-induced Parkinson’s diseases in rodents: Virus-based models versus inoculation of exogenous preformed toxic species. J Neurosci Methods 2020; 338:108685. [DOI: 10.1016/j.jneumeth.2020.108685] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/05/2020] [Accepted: 03/10/2020] [Indexed: 11/22/2022]
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18
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Diacylglycerol kinase δ destabilizes serotonin transporter protein through the ubiquitin-proteasome system. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158608. [DOI: 10.1016/j.bbalip.2019.158608] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/13/2019] [Accepted: 12/27/2019] [Indexed: 01/27/2023]
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19
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Brás IC, Dominguez-Meijide A, Gerhardt E, Koss D, Lázaro DF, Santos PI, Vasili E, Xylaki M, Outeiro TF. Synucleinopathies: Where we are and where we need to go. J Neurochem 2020; 153:433-454. [PMID: 31957016 DOI: 10.1111/jnc.14965] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/24/2022]
Abstract
Synucleinopathies are a group of disorders characterized by the accumulation of inclusions rich in the a-synuclein (aSyn) protein. This group of disorders includes Parkinson's disease, dementia with Lewy bodies (DLB), multiple systems atrophy, and pure autonomic failure (PAF). In addition, genetic alterations (point mutations and multiplications) in the gene encoding for aSyn (SNCA) are associated with familial forms of Parkinson's disease, the most common synucleinopathy. The Synuclein Meetings are a series that has been taking place every 2 years for about 12 years. The Synuclein Meetings bring together leading experts in the field of Synuclein and related human conditions with the goal of discussing and advancing the research. In 2019, the Synuclein meeting took place in Ofir, a city in the outskirts of Porto, Portugal. The meeting, entitled "Synuclein Meeting 2019: Where we are and where we need to go", brought together >300 scientists studying both clinical and molecular aspects of synucleinopathies. The meeting covered a many of the open questions in the field, in a format that prompted open discussions between the participants, and underscored the need for additional research that, hopefully, will lead to future therapies for a group of as of yet incurable disorders. Here, we provide a summary of the topics discussed in each session and highlight what we know, what we do not know, and what progress needs to be made in order to enable the field to continue to advance. We are confident this systematic assessment of where we stand will be useful to steer the field and contribute to filling knowledge gaps that may form the foundations for future therapeutic strategies, which is where we need to go.
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Affiliation(s)
- Inês Caldeira Brás
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Antonio Dominguez-Meijide
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Ellen Gerhardt
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - David Koss
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Diana F Lázaro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Patrícia I Santos
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Eftychia Vasili
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Mary Xylaki
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Tiago Fleming Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK.,Max Planck Institute for Experimental Medicine, Göttingen, Germany
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Vegas-Suarez S, Paredes-Rodriguez E, Aristieta A, Lafuente JV, Miguelez C, Ugedo L. Dysfunction of serotonergic neurons in Parkinson's disease and dyskinesia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 146:259-279. [PMID: 31349930 DOI: 10.1016/bs.irn.2019.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra, the depletion of striatal dopamine and the presence of Lewy aggregates containing alpha-synuclein. Clinically, there are motor impairments involving cardinal movement symptoms, bradykinesia, resting tremor, muscle rigidity, and postural abnormalities, along with non-motor symptoms such as sleep, behavior and mood disorders. The current treatment for PD focuses on restoring dopaminergic neurotransmission by l-3,4-dihydroxyphenylalanine (levodopa), which loses therapeutic efficacy and induces disabling abnormal involuntary movements known as levodopa-induced dyskinesia (LID) after several years. Evidence indicates that the pathophysiology of both PD and LID disorders is also associated with the dysfunctional activity of the serotonergic (5-HT) neurons that may be responsible for motor and non-motor disturbances. The main population of 5-HT neurons is located in the dorsal raphe nuclei (DRN), which provides extensive innervation to almost the entire neuroaxis and controls multiple functions in the brain. The degeneration of DRN 5-HT neurons occurs in early PD. These neurons can also take exogenous levodopa to transform it into dopamine, which may disturb neuron activity. This review will provide an overview of the underlying mechanisms responsible for 5-HT dysfunction and its clinical relevance in PD and dyskinesia.
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Affiliation(s)
- Sergio Vegas-Suarez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain
| | - Elena Paredes-Rodriguez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain
| | - Asier Aristieta
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Jose V Lafuente
- Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; Nanosurgery, Biocruces Health Research Institute, Barakaldo, Spain
| | - Cristina Miguelez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain
| | - Luisa Ugedo
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain.
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Serotonergic pathology and disease burden in the premotor and motor phase of A53T α-synuclein parkinsonism: a cross-sectional study. Lancet Neurol 2019; 18:748-759. [PMID: 31229470 DOI: 10.1016/s1474-4422(19)30140-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/01/2019] [Accepted: 04/03/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND Because of the highly penetrant gene mutation and clinical features consistent with idiopathic Parkinson's disease, carriers of the autosomal dominant Ala53Thr (A53T; 209G→A) point mutation in the α-synuclein (SNCA) gene are an ideal population to study the premotor phase and evolution of Parkinson's pathology. Given the known neurochemical changes in the serotonergic system and their association with symptoms of Parkinson's disease, we hypothesised that carriers of the A53T SNCA mutation might show abnormalities in the serotonergic neurotransmitter system before the diagnosis of Parkinson's disease, and that this pathology might be associated with measures of Parkinson's burden. METHODS In this cross-sectional study, we recruited carriers of the A53T SNCA mutation from specialist Movement Disorders clinics in Athens, Greece, and Salerno, Italy, and a cohort of healthy controls with no personal or family history of neurological or psychiatric disorders from London, UK (recruited via public advertisement) who were age matched to the A53T SNCA carriers. We also recruited one cohort of patients with idiopathic Parkinson's disease (cohort 1) from Movement Disorders clinics in London, UK, and retrieved data on a second cohort of such patients (cohort 2; n=40) who had been scanned with a different scanner. 7-day continuous recording of motor function was used to determine the Parkinson's disease status of the A53T carriers. To assess whether serotonergic abnormalities were present, we used [11C]DASB PET non-displaceable binding to quantify serotonin transporter density. We constructed brain topographic maps reflecting Braak stages 1-6 and used these as seed maps to calculate [11C]DASB non-displaceable binding potential in our cohort of A53T SNCA carriers. Additionally, all participants underwent a battery of clinical assessments to determine motor and non-motor symptoms and cognitive status, and [123I]FP-CIT single-photon emission CT (SPECT) to assess striatal dopamine transporter binding and MRI for volumetric analyses to assess whether pathology is associated with measures of Parkinson's disease burden. FINDINGS Between Sept 1, 2016, and Sept 30, 2018, we recruited 14 A53T SNCA carriers, 25 healthy controls, and 25 patients with idiopathic Parkinson's disease. Seven (50%) of 14 A53T SCNA carriers were confirmed to have motor symptoms and confirmed to have Parkinson's disease, and the absence of motor symptoms was confirmed in seven (50%) A53T SCNA carriers (ie, premotor), in whom [123I]FP-CIT SPECT confirmed the absence of striatal dopaminergic deficits. Compared with healthy controls, premotor A53T SNCA carriers showed loss of [11C]DASB non-displaceable binding potential in the ventral (p<0·0001) and dorsal (p=0·0002) raphe nuclei, caudate (p=0·00015), putamen (p=0·036), thalamus (p=0·00074), hypothalamus (p<0·0001), amygdala (p=0·0041), and brainstem (p=0·046); and in A53T SNCA carriers with Parkinson's disease this loss was extended to the hippocampus (p=0·0051), anterior (p=0·022) and posterior cingulate (p=0·036), insula (p=0·0051), frontal (p=0·0016), parietal (p=0·019), temporal (p<0·0001), and occipital (p=0·0053) cortices. A53T SNCA carriers with Parkinson's disease showed a loss of striatal [123I]FP-CIT-specific binding ratio compared with healthy controls (p<0·0001). Premotor A53T SNCA carriers had loss of [11C]DASB non-displaceable binding potential in brain areas corresponding to Braak stages 1-3, whereas [11C]DASB non-displaceable binding potential was largely preserved in areas corresponding to Braak stages 4-6. Except for one participant who was diagnosed with Parkinson's disease in the past year, all A53T SNCA carriers with Parkinson's disease had decreases in [11C]DASB non-displaceable binding potential in brain areas corresponding to Braak stages 1-6. Decreases in [11C]DASB non-displaceable binding potential in the brainstem were associated with increased Movement Disorder Score-Unified Parkinson's Disease Rating Scale total scores in all A53T SNCA carriers (r -0·66, 95% CI -0·88 to -0·20; p=0·0099), idiopathic Parkinson's disease cohort 1 (r -0·66, -0·84 to -0·36; p=0·00031), and idiopathic Parkinson's disease cohort 2 (r -0·71, -0·84 to -0·52; p<0·0001). INTERPRETATION The presence of serotonergic pathology in premotor A53T SNCA carriers preceded development of dopaminergic pathology and motor symptoms and was associated with disease burden, highlighting the potential early role of serotonergic pathology in the progression of Parkinson's disease. Our findings provide evidence that molecular imaging of serotonin transporters could be used to visualise premotor pathology of Parkinson's disease in vivo. Future work might establish whether serotonin transporter imaging is suitable as an adjunctive tool for screening and monitoring progression for individuals at risk or patients with Parkinson's disease to complement dopaminergic imaging, or as a marker of Parkinson's burden in clinical trials. FUNDING Lily Safra Hope Foundation and National Institute for Health Research (NIHR) Biomedical Research Centre at King's College London.
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Alpha-Synuclein RNA Expression is Increased in Major Depression. Int J Mol Sci 2019; 20:ijms20082029. [PMID: 31027150 PMCID: PMC6515395 DOI: 10.3390/ijms20082029] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/18/2019] [Accepted: 04/20/2019] [Indexed: 01/08/2023] Open
Abstract
Alpha-synuclein (SNCA) is a small membrane protein that plays an important role in neuro-psychiatric diseases. It is best known for its abnormal subcellular aggregation in Lewy bodies that serves as a hallmark of Parkinson’s disease (PD). Due to the high comorbidity of PD with depression, we investigated the role of SNCA in patients suffering from major depressive disorder (MDD). SNCA mRNA expression levels were analyzed in peripheral blood cells of MDD patients and a healthy control group. SNCA mRNA expression was positively correlated with severity of depression as indicated by psychometric assessment. We found a significant increase in SNCA mRNA expression levels in severely depressed patients compared with controls. Thus, SNCA analysis could be a helpful target in the search for biomarkers of MDD.
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Baudry A, Pietri M, Launay JM, Kellermann O, Schneider B. Multifaceted Regulations of the Serotonin Transporter: Impact on Antidepressant Response. Front Neurosci 2019; 13:91. [PMID: 30809118 PMCID: PMC6379337 DOI: 10.3389/fnins.2019.00091] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/25/2019] [Indexed: 12/16/2022] Open
Abstract
Serotonin transporter, SERT (SLC64A for solute carrier family 6, member A4), is a twelve transmembrane domain (TMDs) protein that assumes the uptake of serotonin (5-HT) through dissipation of the Na+ gradient established by the electrogenic pump Na/K ATPase. Abnormalities in 5-HT level and signaling have been associated with various disorders of the central nervous system (CNS) such as depression, obsessive-compulsive disorder, anxiety disorders, and autism spectrum disorder. Since the 50s, SERT has raised a lot of interest as being the target of a class of antidepressants, the Serotonin Selective Reuptake Inhibitors (SSRIs), used in clinics to combat depressive states. Because of the refractoriness of two-third of patients to SSRI treatment, a better understanding of the mechanisms regulating SERT functions is of priority. Here, we review how genetic and epigenetic regulations, post-translational modifications of SERT, and specific interactions between SERT and a set of diverse partners influence SERT expression, trafficking to and away from the plasma membrane and activity, in connection with the neuronal adaptive cell response to SSRI antidepressants.
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Affiliation(s)
- Anne Baudry
- INSERM UMR-S 1124, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1124, Paris, France
| | - Mathea Pietri
- INSERM UMR-S 1124, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1124, Paris, France
| | - Jean-Marie Launay
- Hôpital Lariboisière, AP-HP, INSERM UMR-S 942, Paris, France.,Pharma Research Department, Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Odile Kellermann
- INSERM UMR-S 1124, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1124, Paris, France
| | - Benoit Schneider
- INSERM UMR-S 1124, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR-S 1124, Paris, France
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Living in Promiscuity: The Multiple Partners of Alpha-Synuclein at the Synapse in Physiology and Pathology. Int J Mol Sci 2019; 20:ijms20010141. [PMID: 30609739 PMCID: PMC6337145 DOI: 10.3390/ijms20010141] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 12/18/2022] Open
Abstract
Alpha-synuclein (α-syn) is a small protein that, in neurons, localizes predominantly to presynaptic terminals. Due to elevated conformational plasticity, which can be affected by environmental factors, in addition to undergoing disorder-to-order transition upon interaction with different interactants, α-syn is counted among the intrinsically disordered proteins (IDPs) family. As with many other IDPs, α-syn is considered a hub protein. This function is particularly relevant at synaptic sites, where α-syn is abundant and interacts with many partners, such as monoamine transporters, cytoskeletal components, lipid membranes, chaperones and synaptic vesicles (SV)-associated proteins. These protein–protein and protein–lipid membrane interactions are crucial for synaptic functional homeostasis, and alterations in α-syn can cause disruption of this complex network, and thus a failure of the synaptic machinery. Alterations of the synaptic environment or post-translational modification of α-syn can induce its misfolding, resulting in the formation of oligomers or fibrillary aggregates. These α-syn species are thought to play a pathological role in neurodegenerative disorders with α-syn deposits such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), which are referred to as synucleinopathies. Here, we aim at revising the complex and promiscuous role of α-syn at synaptic terminals in order to decipher whether α-syn molecular interactants may influence its conformational state, contributing to its aggregation, or whether they are just affected by it.
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Lu Q, Komenoi S, Usuki T, Takahashi D, Sakane F. Abnormalities of the serotonergic system in diacylglycerol kinase δ-deficient mouse brain. Biochem Biophys Res Commun 2018; 497:1031-1037. [DOI: 10.1016/j.bbrc.2018.02.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/20/2018] [Indexed: 10/17/2022]
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Das AK, Maity BK, Surendran D, Tripathy U, Maiti S. Label-Free Ratiometric Imaging of Serotonin in Live Cells. ACS Chem Neurosci 2017; 8:2369-2373. [PMID: 28796481 DOI: 10.1021/acschemneuro.7b00132] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ratiometric imaging can quantitatively measure changes in cellular analyte concentrations using specially designed fluorescent labels. We describe a label-free ratiometric imaging technique for direct detection of changes in intravesicular serotonin concentration in live cells. At higher concentrations, serotonin forms transient oligomers whose ultraviolet emission is shifted to longer wavelengths. We access the ultraviolet/blue emission using relatively benign three-photon excitation and split it into two imaging channels, whose ratio reports the concentration. The technique is sensitive at a physiologically relevant concentration range (10-150 mM serotonin). As a proof of principle, we measure the increase of intravesicular serotonin concentration with the addition of external serotonin. In general, since emission spectra of molecules are often sensitive to concentration, our method may be applicable to other natively fluorescent intracellular molecules which are present at high concentrations.
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Affiliation(s)
- Anand Kant Das
- Department
of Chemical Sciences, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba,
Mumbai 400005, India
| | - Barun Kumar Maity
- Department
of Chemical Sciences, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba,
Mumbai 400005, India
| | - Dayana Surendran
- Department
of Chemical Sciences, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba,
Mumbai 400005, India
| | - Umakanta Tripathy
- Department
of Applied Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004 Jharkhand, India
| | - Sudipta Maiti
- Department
of Chemical Sciences, Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba,
Mumbai 400005, India
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The Gain-of-Function Integrin β3 Pro33 Variant Alters the Serotonin System in the Mouse Brain. J Neurosci 2017; 37:11271-11284. [PMID: 29038237 DOI: 10.1523/jneurosci.1482-17.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 12/26/2022] Open
Abstract
Engagement of integrins by the extracellular matrix initiates signaling cascades that drive a variety of cellular functions, including neuronal migration and axonal pathfinding in the brain. Multiple lines of evidence link the ITGB3 gene encoding the integrin β3 subunit with the serotonin (5-HT) system, likely via its modulation of the 5-HT transporter (SERT). The ITGB3 coding polymorphism Leu33Pro (rs5918, PlA2) produces hyperactive αvβ3 receptors that influence whole-blood 5-HT levels and may influence the risk for autism spectrum disorder (ASD). Using a phenome-wide scan of psychiatric diagnoses, we found significant, male-specific associations between the Pro33 allele and attention-deficit hyperactivity disorder and ASDs. Here, we used knock-in (KI) mice expressing an Itgb3 variant that phenocopies the human Pro33 variant to elucidate the consequences of constitutively enhanced αvβ3 signaling to the 5-HT system in the brain. KI mice displayed deficits in multiple behaviors, including anxiety, repetitive, and social behaviors. Anatomical studies revealed a significant decrease in 5-HT synapses in the midbrain, accompanied by decreases in SERT activity and reduced localization of SERTs to integrin adhesion complexes in synapses of KI mice. Inhibition of focal adhesion kinase (FAK) rescued SERT function in synapses of KI mice, demonstrating that constitutive active FAK signaling downstream of the Pro32Pro33 integrin αvβ3 suppresses SERT activity. Our studies identify a complex regulation of 5-HT homeostasis and behaviors by integrin αvβ3, revealing an important role for integrins in modulating risk for neuropsychiatric disorders.SIGNIFICANCE STATEMENT The integrin β3 Leu33Pro coding polymorphism has been associated with autism spectrum disorders (ASDs) within a subgroup of patients with elevated blood 5-HT levels, linking integrin β3, 5-HT, and ASD risk. We capitalized on these interactions to demonstrate that the Pro33 coding variation in the murine integrin β3 recapitulates the sex-dependent neurochemical and behavioral attributes of ASD. Using state-of-the-art techniques, we show that presynaptic 5-HT function is altered in these mice, and that the localization of 5-HT transporters to specific compartments within the synapse, disrupted by the integrin β3 Pro33 mutation, is critical for appropriate reuptake of 5-HT. Our studies provide fundamental insight into the genetic network regulating 5-HT neurotransmission in the CNS that is also associated with ASD risk.
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Das AK, Pandit R, Maiti S. Effect of amyloids on the vesicular machinery: implications for somatic neurotransmission. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0187. [PMID: 26009766 DOI: 10.1098/rstb.2014.0187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Certain neurodegenerative diseases are thought to be initiated by the aggregation of amyloidogenic proteins. However, the mechanism underlying toxicity remains obscure. Most of the suggested mechanisms are generic in nature and do not directly explain the neuron-type specific lesions observed in many of these diseases. Some recent reports suggest that the toxic aggregates impair the synaptic vesicular machinery. This may lead to an understanding of the neuron-type specificity observed in these diseases. A disruption of the vesicular machinery can also be deleterious for extra-synaptic, especially somatic, neurotransmission (common in serotonergic and dopaminergic systems which are specifically affected in Alzheimer's disease (AD) and Parkinson's disease (PD), respectively), though this relationship has remained unexplored. In this review, we discuss amyloid-induced damage to the neurotransmitter vesicular machinery, with an eye on the possible implications for somatic exocytosis. We argue that the larger size of the system, and the availability of multi-photon microscopy techniques for directly visualizing monoamines, make the somatic exocytosis machinery a more tractable model for understanding the effect of amyloids on all types of vesicular neurotransmission. Indeed, exploring this neglected connection may not just be important, it may be a more fruitful route for understanding AD and PD.
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Affiliation(s)
- Anand Kant Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
| | - Rucha Pandit
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
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Kohl Z, Ben Abdallah N, Vogelgsang J, Tischer L, Deusser J, Amato D, Anderson S, Müller CP, Riess O, Masliah E, Nuber S, Winkler J. Severely impaired hippocampal neurogenesis associates with an early serotonergic deficit in a BAC α-synuclein transgenic rat model of Parkinson's disease. Neurobiol Dis 2015; 85:206-217. [PMID: 26523794 DOI: 10.1016/j.nbd.2015.10.021] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 10/20/2015] [Accepted: 10/27/2015] [Indexed: 12/24/2022] Open
Abstract
Parkinson's disease (PD) is a multisystem disorder, involving several monoaminergic neurotransmitter systems resulting in a broad range of motor and non-motor symptoms. Pathological hallmarks of PD are the loss of dopaminergic neurons and the accumulation of alpha-synuclein, however also being present in the serotonergic raphe nuclei early in the disease course. The dysfunction of the serotonergic system projecting to the hippocampus may contribute to early non-motor symptoms such as anxiety and depression. The adult hippocampal dentate gyrus (DG), a unique niche of the forebrain continuously generating new neurons, may particularly present enhanced susceptibility towards accumulating alpha-synuclein levels. The underlying molecular mechanisms in the context of neuronal maturation and survival of new-born neurons are yet not well understood. To characterize the effects of overexpression of human full-length alpha-synuclein on hippocampal cellular and synaptic plasticity, we used a recently generated BAC alpha-synuclein transgenic rat model showing important features of PD such as widespread and progressive alpha-synuclein aggregation pathology, dopamine loss and age-dependent motor decline. At the age of four months, thus prior to the occurrence of the motor phenotype, we observed a profoundly impaired dendritogenesis of neuroblasts in the hippocampal DG resulting in severely reduced survival of adult new-born neurons. Diminished neurogenesis concurred with a serotonergic deficit in the hippocampus as defined by reduced levels of serotonin (5-HT) 1B receptor, decreased 5-HT neurotransmitter levels, and a loss of serotonergic nerve terminals innervating the DG/CA3 subfield, while the number of serotonergic neurons in the raphe nuclei remained unchanged. Moreover, alpha-synuclein overexpression reduced proteins involved in vesicle release, in particular synapsin-1 and Rab3 interacting molecule (RIM3), in conjunction with an altered ultrastructural architecture of hippocampal synapses. Importantly, BAC alpha-synuclein rats showed an early anxiety-like phenotype consisting of reduced exploratory behavior and feeding. Taken together, these findings imply that accumulating alpha-synuclein severely affects hippocampal neurogenesis paralleled by impaired 5-HT neurotransmission prior to the onset of aggregation pathology and overt motor deficits in this transgenic rat model of PD.
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Affiliation(s)
- Zacharias Kohl
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Nada Ben Abdallah
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Jonathan Vogelgsang
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Lucas Tischer
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Janina Deusser
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Davide Amato
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Scott Anderson
- Department of Neurosciences and Pathology, University of California, San Diego, La Jolla, USA
| | - Christian P Müller
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Eliezer Masliah
- Department of Neurosciences and Pathology, University of California, San Diego, La Jolla, USA
| | - Silke Nuber
- Department of Neurosciences and Pathology, University of California, San Diego, La Jolla, USA; Department of Psychiatry, University of California, San Diego, La Jolla, USA; Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.
| | - Jürgen Winkler
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
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Butler B, Saha K, Rana T, Becker JP, Sambo D, Davari P, Goodwin JS, Khoshbouei H. Dopamine Transporter Activity Is Modulated by α-Synuclein. J Biol Chem 2015; 290:29542-54. [PMID: 26442590 DOI: 10.1074/jbc.m115.691592] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Indexed: 12/24/2022] Open
Abstract
The duration and strength of the dopaminergic signal are regulated by the dopamine transporter (DAT). Drug addiction and neurodegenerative and neuropsychiatric diseases have all been associated with altered DAT activity. The membrane localization and the activity of DAT are regulated by a number of intracellular proteins. α-Synuclein, a protein partner of DAT, is implicated in neurodegenerative disease and drug addiction. Little is known about the regulatory mechanisms of the interaction between DAT and α-synuclein, the cellular location of this interaction, and the functional consequences of this interaction on the basal, amphetamine-induced DAT-mediated dopamine efflux, and membrane microdomain distribution of the transporter. Here, we found that the majority of DAT·α-synuclein protein complexes are found at the plasma membrane of dopaminergic neurons or mammalian cells and that the amphetamine-mediated increase in DAT activity enhances the association of these proteins at the plasma membrane. Further examination of the interaction of DAT and α-synuclein revealed a transient interaction between these two proteins at the plasma membrane. Additionally, we found DAT-induced membrane depolarization enhances plasma membrane localization of α-synuclein, which in turn increases dopamine efflux and enhances DAT localization in cholesterol-rich membrane microdomains.
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Affiliation(s)
- Brittany Butler
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
| | - Kaustuv Saha
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
| | - Tanu Rana
- the Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, Tennessee 37208
| | - Jonas P Becker
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
| | - Danielle Sambo
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
| | - Paran Davari
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
| | - J Shawn Goodwin
- the Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, Tennessee 37208
| | - Habibeh Khoshbouei
- From the Departments of Neuroscience and Psychiatry University of Florida, Gainesville, Florida 32611 and
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Deusser J, Schmidt S, Ettle B, Plötz S, Huber S, Müller CP, Masliah E, Winkler J, Kohl Z. Serotonergic dysfunction in the A53T alpha-synuclein mouse model of Parkinson's disease. J Neurochem 2015. [PMID: 26201615 DOI: 10.1111/jnc.13253] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Parkinson's disease, neuropathologically defined by the aggregation of α-synuclein, is characterized by neuropsychiatric symptoms such as depression and anxiety preceding the onset of motor symptoms. A loss of serotonergic neurons or their projections into the hippocampus and alterations in serotonin release may be linked to these symptoms. Here, we investigate the effect of human A53T α-synuclein on serotonergic neurons using 12-months-old transgenic mice. We detected human α-synuclein in the perikarya of brainstem median and dorsal raphe neurons as well as in serotonergic fibers in the hippocampus. Despite intracellular α-synuclein accumulation there was no loss of serotonergic neurons in dorsal and median raphe nuclei of A53T α-synuclein mice. However, serotonin levels were significantly reduced in the brainstem. In addition, serotonergic fiber density in the dorsal dentate gyrus was significantly less dense in transgenic mice. Interestingly, we detected a significantly compromised increase in doublecortin+ neuroblasts after chronic treatment with fluoxetine at the site of reduced serotonergic innervation, the infrapyramidal blade of the dorsal dentate gyrus in A53T α-synuclein mice. This suggests that α-synuclein affects serotonergic projections in a spatially distinct pattern within the hippocampus thereby influencing the response to antidepressant treatment.
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Affiliation(s)
- Janina Deusser
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefanie Schmidt
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Benjamin Ettle
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Sonja Plötz
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Sabine Huber
- Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Christian P Müller
- Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Eliezer Masliah
- Department of Neurosciences and Pathology, University of California San Diego, La Jolla, California, USA
| | - Jürgen Winkler
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Zacharias Kohl
- Department of Molecular Neurology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
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Gruden MA, Davydova TV, Narkevich VB, Fomina VG, Wang C, Kudrin VS, Morozova-Roche LA, Sewell RD. Noradrenergic and serotonergic neurochemistry arising from intranasal inoculation with α-synuclein aggregates which incite parkinsonian-like symptoms. Behav Brain Res 2015; 279:191-201. [DOI: 10.1016/j.bbr.2014.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/28/2014] [Accepted: 11/01/2014] [Indexed: 12/13/2022]
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Abstract
α-Synuclein is an abundant neuronal protein which localizes predominantly to presynaptic terminals, and is strongly linked genetically and pathologically to Parkinson's disease and other neurodegenerative diseases. While the accumulation of α-synuclein in the form of misfolded oligomers and large aggregates defines multiple neurodegenerative diseases called "synucleinopathies", its cellular function has remained largely unclear, and is the subject of intense investigation. In this review, I focus on the structural characteristics of α-synuclein, its cellular and subcellular localization, and discuss how this relates to its function in neurons, in particular at the neuronal synapse.
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Affiliation(s)
- Jacqueline Burré
- Appel Institute for Alzheimer’s Disease Research, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY, USA
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Snead D, Eliezer D. Alpha-synuclein function and dysfunction on cellular membranes. Exp Neurobiol 2014; 23:292-313. [PMID: 25548530 PMCID: PMC4276801 DOI: 10.5607/en.2014.23.4.292] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/15/2014] [Accepted: 11/16/2014] [Indexed: 11/19/2022] Open
Abstract
Alpha-synuclein is a small neuronal protein that is closely associated with the etiology of Parkinson's disease. Mutations in and alterations in expression levels of alpha-synuclein cause autosomal dominant early onset heredity forms of Parkinson's disease, and sporadic Parkinson's disease is defined in part by the presence of Lewy bodies and Lewy neurites that are composed primarily of alpha-synuclein deposited in an aggregated amyloid fibril state. The normal function of alpha-synuclein is poorly understood, and the precise mechanisms by which it leads to toxicity and cell death are also unclear. Although alpha-synuclein is a highly soluble, cytoplasmic protein, it binds to a variety of cellular membranes of different properties and compositions. These interactions are considered critical for at least some normal functions of alpha-synuclein, and may well play critical roles in both the aggregation of the protein and its mechanisms of toxicity. Here we review the known features of alpha-synuclein membrane interactions in the context of both the putative functions of the protein and of its pathological roles in disease.
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Affiliation(s)
- David Snead
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
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Iwata K, Matsuzaki H, Tachibana T, Ohno K, Yoshimura S, Takamura H, Yamada K, Matsuzaki S, Nakamura K, Tsuchiya KJ, Matsumoto K, Tsujii M, Sugiyama T, Katayama T, Mori N. N-ethylmaleimide-sensitive factor interacts with the serotonin transporter and modulates its trafficking: implications for pathophysiology in autism. Mol Autism 2014; 5:33. [PMID: 24834316 PMCID: PMC4022412 DOI: 10.1186/2040-2392-5-33] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/24/2014] [Indexed: 01/23/2023] Open
Abstract
Background Changes in serotonin transporter (SERT) function have been implicated in autism. SERT function is influenced by the number of transporter molecules present at the cell surface, which is regulated by various cellular mechanisms including interactions with other proteins. Thus, we searched for novel SERT-binding proteins and investigated whether the expression of one such protein was affected in subjects with autism. Methods Novel SERT-binding proteins were examined by a pull-down system. Alterations of SERT function and membrane expression upon knockdown of the novel SERT-binding protein were studied in HEK293-hSERT cells. Endogenous interaction of SERT with the protein was evaluated in mouse brains. Alterations in the mRNA expression of SERT (SLC6A4) and the SERT-binding protein in the post-mortem brains and the lymphocytes of autism patients were compared to nonclinical controls. Results N-ethylmaleimide-sensitive factor (NSF) was identified as a novel SERT-binding protein. NSF was co-localized with SERT at the plasma membrane, and NSF knockdown resulted in decreased SERT expression at the cell membranes and decreased SERT uptake function. NSF was endogenously co-localized with SERT and interacted with SERT. While SLC6A4 expression was not significantly changed, NSF expression tended to be reduced in post-mortem brains, and was significantly reduced in lymphocytes of autistic subjects, which correlated with the severity of the clinical symptoms. Conclusions These data clearly show that NSF interacts with SERT under physiological conditions and is required for SERT membrane trafficking and uptake function. A possible role for NSF in the pathophysiology of autism through modulation of SERT trafficking, is suggested.
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Affiliation(s)
- Keiko Iwata
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan ; Department of Development of Functional Brain Activities, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Fukui, Japan
| | - Hideo Matsuzaki
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan ; Department of Development of Functional Brain Activities, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Fukui, Japan ; Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Taro Tachibana
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Koji Ohno
- Department of Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Saori Yoshimura
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | - Hironori Takamura
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan ; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Kohei Yamada
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan ; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Shinsuke Matsuzaki
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan
| | - Kazuhiko Nakamura
- Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kenji J Tsuchiya
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kaori Matsumoto
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masatsugu Tsujii
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan ; Faculty of Contemporary Sociology, Chukyo University, Toyota, Japan
| | - Toshirou Sugiyama
- Department of Child and Adolescent Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Taiichi Katayama
- Department of Molecular Brain Science, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan
| | - Norio Mori
- Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan ; Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Cuyas E, Robledo P, Pizarro N, Farré M, Puerta E, Aguirre N, de la Torre R. 3,4-methylenedioxymethamphetamine induces gene expression changes in rats related to serotonergic and dopaminergic systems, but not to neurotoxicity. Neurotox Res 2013; 25:161-9. [PMID: 23949956 DOI: 10.1007/s12640-013-9416-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/16/2013] [Accepted: 07/30/2013] [Indexed: 11/24/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is an amphetamine derivative widely abused by young adults. Although many studies have reported that relatively high doses of MDMA deplete serotonin (5-HT) content and decrease the availability of serotonin transporters (5-HTT), limited evidence is available as to the adaptive mechanisms taking place in gene expression levels in the brain following a dosing regimen of MDMA comparable to human consumption. In order to further clarify this issue, we used quantitative PCR to study the long-term changes induced by acute administration of MDMA (5 mg/kg × 3) in the expression of genes related to serotonergic and dopaminergic systems, as well as those related to cellular toxicity in the cortex, hippocampus, striatum, and brain stem of rats. Seven days after MDMA administration, we found a significantly lower expression of the 5-HTT (Slc6a4) and the vesicular monoamine transporter (Slc18a2) genes in the brain stem area. In the hippocampus, monoamine oxidase B (Maob) and tryptophan hydroxylase 2 (Tph2) gene expressions were increased. In the striatum, tyrosine hydroxylase (Th) expression was decreased, and a lower expression of α-synuclein (Snca) was observed in the cortex. In contrast, no significant changes were observed in the genes considered to be biomarkers of toxicity including the glial fibrillary acidic protein (Gfap) and the heat-shock 70 kD protein 1A (Hspa1a) in any of the structures assayed. These results suggest that MDMA promotes adaptive changes in genes related to serotonergic and dopaminergic functionality, but not in genes related to neurotoxicity.
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Affiliation(s)
- Elisabet Cuyas
- Human Pharmacology and Clinical Neurosciences Research Group, Neurosciences Research Program, IMIM-Hospital del Mar Medical Research Institute, Parc de Recerca Biomèdica de Barcelona, Doctor Aiguader, 88, 08003, Barcelona, Spain
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Oaks AW, Marsh-Armstrong N, Jones JM, Credle JJ, Sidhu A. Synucleins antagonize endoplasmic reticulum function to modulate dopamine transporter trafficking. PLoS One 2013; 8:e70872. [PMID: 23967127 PMCID: PMC3742698 DOI: 10.1371/journal.pone.0070872] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 06/25/2013] [Indexed: 01/20/2023] Open
Abstract
Synaptic re-uptake of dopamine is dependent on the dopamine transporter (DAT), which is regulated by its distribution to the cell surface. DAT trafficking is modulated by the Parkinson's disease-linked protein alpha-synuclein, but the contribution of synuclein family members beta-synuclein and gamma-synuclein to DAT trafficking is not known. Here we use SH-SY5Y cells as a model of DAT trafficking to demonstrate that all three synucleins negatively regulate cell surface distribution of DAT. Under these conditions the synucleins limit export of DAT from the endoplasmic reticulum (ER) by impairment of the ER-Golgi transition, leading to accumulation of DAT in this compartment. This mechanism for regulating DAT export indirectly through effects on ER and Golgi function represents a previously unappreciated role for the extended synuclein family that is likely applicable to trafficking of the many proteins that rely on the secretory pathway.
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Affiliation(s)
- Adam W. Oaks
- Laboratory of Molecular Neurochemistry, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, D.C., United States of America
| | - Nicholas Marsh-Armstrong
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, Maryland, United States of America
| | - Jessica M. Jones
- Laboratory of Molecular Neurochemistry, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, D.C., United States of America
| | - Joel J. Credle
- Laboratory of Molecular Neurochemistry, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, D.C., United States of America
| | - Anita Sidhu
- Laboratory of Molecular Neurochemistry, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, Washington, D.C., United States of America
- * E-mail:
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Bellucci A, Zaltieri M, Navarria L, Grigoletto J, Missale C, Spano P. From α-synuclein to synaptic dysfunctions: new insights into the pathophysiology of Parkinson's disease. Brain Res 2012; 1476:183-202. [PMID: 22560500 DOI: 10.1016/j.brainres.2012.04.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/30/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
Abstract
Alpha-synuclein is a natively unfolded protein playing a key role in the regulation of several neuronal synaptic functions in physiological and pathological conditions. Many studies, over the past years, have shown that it is actively involved in PD pathophysiology. Alpha-synuclein is integrated in a complex network of neuronal processes through the interaction with cytosolic and synaptic proteins. Hence, it is not the sole α-synuclein pathology but its effects on diverse protein partners and specific cellular pathways in the membrane and/or cytosolic districts such as endoplasmic reticulum/Golgi, axonal and synaptic compartments of dopaminergic neurons, that may cause the onset of neuronal cell dysfunction and degeneration which are among the key pathological features of the PD brain. Here we summarize a series of experimental data supporting that α-synuclein aggregation may induce dysfunction and degeneration of synapses via these multiple mechanisms. Taken together, these data add new insights into the complex mechanisms underlying synaptic derangement in PD and other α-synucleinopathies. This article is part of a Special Issue entitled: Brain Integration.
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Affiliation(s)
- Arianna Bellucci
- Division of Pharmacology, Department of Biomedical Sciences and Biotechnologies and National Institute of Neuroscience, University of Brescia, Brescia, Italy.
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Bellucci A, Navarria L, Zaltieri M, Missale C, Spano P. α-Synuclein synaptic pathology and its implications in the development of novel therapeutic approaches to cure Parkinson's disease. Brain Res 2011; 1432:95-113. [PMID: 22153624 DOI: 10.1016/j.brainres.2011.11.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/11/2011] [Accepted: 11/11/2011] [Indexed: 12/24/2022]
Abstract
Parkinson's disease (PD) is characterized by a progressive loss of dopamine (DA) neurons of the nigrostriatal system and by the presence of Lewy bodies (LB), proteinaceous inclusions mainly composed of filamentous α-synuclein aggregates. Alpha-synuclein is a natively unfolded protein which plays a central role in the control of dopaminergic neuronal functions and which is thought to be critically implicated in PD pathophysiology. Indeed, besides the fact that α-synuclein is the main protein component of LB, genetic studies showed that mutations and multiplications of the α-synuclein gene are responsible for the onset of familial forms of PD. A large body of evidence indicates that α-synuclein pathology at dopaminergic synapses may underlie the onset of neuronal cell dysfunction and degeneration in the PD brain. Thus, since the available therapeutic approaches to cure this disease are still limited, we hypothesized that the analysis of the α-synuclein synaptic proteome/lipidome may represent a tool to identify novel potential therapeutic targets to cure this disorder. We thus performed a critical review of studies describing α-synuclein pathophysiology at synaptic sites in experimental models of PD and in this paper we outline the most relevant findings regarding the specific modulatory effects exerted by α-synuclein in the control of synaptic functions in physiological and pathological conditions. The conclusions of these studies allow to single out novel potential therapeutic targets among the α-synuclein synaptic partners. These targets may be considered for the development of new pharmacological and gene-based strategies to cure PD.
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Affiliation(s)
- Arianna Bellucci
- Division of Pharmacology, Department of Biomedical Sciences and Biotechnology and National Institute of Neuroscience - Italy, School of Medicine, University of Brescia, Brescia, Italy.
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Olfactory neuron-specific expression of A30P alpha-synuclein exacerbates dopamine deficiency and hyperactivity in a novel conditional model of early Parkinson's disease stages. Neurobiol Dis 2011; 44:192-204. [DOI: 10.1016/j.nbd.2011.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/05/2011] [Accepted: 06/26/2011] [Indexed: 11/19/2022] Open
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Zhong H, Sánchez C, Caron MG. Consideration of allosterism and interacting proteins in the physiological functions of the serotonin transporter. Biochem Pharmacol 2011; 83:435-42. [PMID: 21983034 DOI: 10.1016/j.bcp.2011.09.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 09/19/2011] [Indexed: 11/25/2022]
Abstract
The serotonin transporter (SERT) functions to transport serotonin (5-HT) from the extracellular space into neurons to maintain homeostatic control of 5-HT. It is the molecular target for selective serotonin reuptake inhibitor (SSRI) antidepressants. Preclinical research has shown that some SERT inhibitors can bind to two distinct binding sites on the SERT, a primary high affinity binding site and a low affinity allosteric binding site. Mutational studies of the SERT and computational modeling methods with escitalopram resulted in the identification of key amino acid residues important for the function of the allosteric binding site. While this allosteric binding site appears to influence the clinical efficacy of escitalopram under physiological conditions, the molecular mechanism of this effect is still poorly understood and may involve a large network of protein-protein interactions with the SERT. Dynamic interfaces between the SERT and the SERT interacting proteins (SIPs) potentially influence not only the SERT on its uptake function, its regulation, and trafficking, but also on known as well as yet to be identified non-canonical signaling pathways through SIPs. In this commentary, we outline approaches in the areas of selective small-molecule allosteric compound discovery, biochemistry, in vivo genetic knock-in mouse models, as well as computational and structural biology. These studies of the intra-molecular allosteric modulation of the SERT in the context of the myriad of potential inter-molecular signaling interactions with SIPs may help uncover unknown physiological functions of the SERT.
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Affiliation(s)
- Huailing Zhong
- U-Pharm Laboratories LLC, 239 New Road, Suite A-107, Parsippany, NJ 07054, USA.
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42
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Sager JJ, Torres GE. Proteins interacting with monoamine transporters: current state and future challenges. Biochemistry 2011; 50:7295-310. [PMID: 21797260 DOI: 10.1021/bi200405c] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Plasma membrane and vesicular transporters for the biogenic amines, dopamine, norepinephrine, and serotonin, represent a group of proteins that play a crucial role in the regulation of neurotransmission. Clinically, mono amine transporters are the primary targets for the actions of many therapeutic agents used to treat mood disorders, as well as the site of action for highly addictive psychostimulants such as cocaine, amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine. Over the past decade, the use of approaches such as yeast two-hybrid and proteomics has identified a multitude of transporter interacting proteins, suggesting that the function and regulation of these transporters are more complex than previously anticipated. With the increasing number of interacting proteins, the rules dictating transporter synthesis, assembly, targeting, trafficking, and function are beginning to be deciphered. Although many of these protein interactions have yet to be fully characterized, current knowledge is beginning to shed light on novel transporter mechanisms involved in monoamine homeostasis, the molecular actions of psychostimulants, and potential disease mechanisms. While future studies resolving the spatial and temporal resolution of these, and yet unknown, interactions will be needed, the realization that monoamine transporters do not work alone opens the path to a plethora of possible pharmacological interventions.
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Affiliation(s)
- Jonathan J Sager
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, United States
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Kristensen AS, Andersen J, Jørgensen TN, Sørensen L, Eriksen J, Loland CJ, Strømgaard K, Gether U. SLC6 neurotransmitter transporters: structure, function, and regulation. Pharmacol Rev 2011; 63:585-640. [PMID: 21752877 DOI: 10.1124/pr.108.000869] [Citation(s) in RCA: 601] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The neurotransmitter transporters (NTTs) belonging to the solute carrier 6 (SLC6) gene family (also referred to as the neurotransmitter-sodium-symporter family or Na(+)/Cl(-)-dependent transporters) comprise a group of nine sodium- and chloride-dependent plasma membrane transporters for the monoamine neurotransmitters serotonin (5-hydroxytryptamine), dopamine, and norepinephrine, and the amino acid neurotransmitters GABA and glycine. The SLC6 NTTs are widely expressed in the mammalian brain and play an essential role in regulating neurotransmitter signaling and homeostasis by mediating uptake of released neurotransmitters from the extracellular space into neurons and glial cells. The transporters are targets for a wide range of therapeutic drugs used in treatment of psychiatric diseases, including major depression, anxiety disorders, attention deficit hyperactivity disorder and epilepsy. Furthermore, psychostimulants such as cocaine and amphetamines have the SLC6 NTTs as primary targets. Beginning with the determination of a high-resolution structure of a prokaryotic homolog of the mammalian SLC6 transporters in 2005, the understanding of the molecular structure, function, and pharmacology of these proteins has advanced rapidly. Furthermore, intensive efforts have been directed toward understanding the molecular and cellular mechanisms involved in regulation of the activity of this important class of transporters, leading to new methodological developments and important insights. This review provides an update of these advances and their implications for the current understanding of the SLC6 NTTs.
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Affiliation(s)
- Anders S Kristensen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Abstract
Although well-studied in the context of neurodegenerative disease, a clear biological function for the synuclein proteins remains elusive. Emerging data indicate a role for synucleins in monoamine neurotransmitter homeostasis. A key regulatory component of monoamine neurotransmission is re-uptake of neurotransmitter by the dopamine transporter, norepinephrine transporter, and serotonin transporter, which are common drug targets in the treatment of depression and other mood disorders. Through interactions with these transporters, the neuronal cytoskeleton, and pre-synaptic scaffolding proteins, α-synuclein, β-synuclein, and γ-synuclein modulate trafficking, expression and function of monoamine transporters at the cell surface, thus playing a central role in regulating monoamine re-uptake.
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Prasad K, Tarasewicz E, Strickland PAO, O’Neill M, Mitchell SN, Merchant K, Tep S, Hilton K, Datwani A, Buttini M, Mueller-Steiner S, Richfield EK. Biochemical and morphological consequences of human α-synuclein expression in a mouse α-synuclein null background. Eur J Neurosci 2011; 33:642-56. [PMID: 21272100 PMCID: PMC3072281 DOI: 10.1111/j.1460-9568.2010.07558.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A consensus about the functions of human wild-type or mutated α-synuclein (αSYN) is lacking. Both forms of αSYN are implicated in Parkinson's disease, whereas the wild-type form is implicated in substance abuse. Interactions with other cellular proteins and organelles may meditate its functions. We developed a series of congenic mouse lines containing various allele doses or combinations of the human wild-type αSYN (hwαSYN) or a doubly mutated (A30P*A53T) αSYN (hm(2) αSYN) in a C57Bl/6J line spontaneously deleted in mouse αSYN (C57BL/6JOla). Both transgenes had a functional role in the nigrostriatal system, demonstrated by significant elevations in striatal catecholamines, metabolites and the enzyme tyrosine hydroxylase compared with null-mice without a transgene. Consequences occurred when the transgenes were expressed at a fraction of the endogenous level. Hemizygous congenic mice did not exhibit any change in the number or size of dopaminergic neurons in the ventral midbrain at 9 months of age. Human αSYN was predominantly located in neuronal cell bodies, neurites, synapses, and in intraneuronal/intraneuritic aggregates. The hm(2) αSYN transgene resulted in more aggregates and dystrophic neurites than did the hw5 transgene. The hwαSYN transgene resulted in higher expression of two striatal proteins, synaptogamin 7 and UCHL1, compared with the levels of the hm(2) αSYN transgene. These observations suggest that mutations in αSYN may impair specific functional domains, leaving others intact. These lines may be useful for exploring interactions between hαSYN and environmental or genetic risk factors in dopamine-related disorders using a mouse model.
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Affiliation(s)
- Kavita Prasad
- Department of Pathology and Lab Medicine Robert Wood Johnson Medical School (RWJMS), University of Medicine and Dentistry New Jersey (UMDNJ), Piscataway, NJ 08854
- Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ 08854
| | - Elizabeth Tarasewicz
- Department of Pathology and Lab Medicine Robert Wood Johnson Medical School (RWJMS), University of Medicine and Dentistry New Jersey (UMDNJ), Piscataway, NJ 08854
- Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ 08854
| | - Pamela A. Ohman Strickland
- Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ 08854
- Department of Biostatistics, School of Public Health, University of Medicine and Dentistry New Jersey (UMDNJ), Piscataway, NJ 08854
| | | | | | | | - Samnang Tep
- Elan Pharmaceuticals Inc., South San Francisco, CA 94080
| | - Kathryn Hilton
- Elan Pharmaceuticals Inc., South San Francisco, CA 94080
| | - Akash Datwani
- Elan Pharmaceuticals Inc., South San Francisco, CA 94080
| | - Manuel Buttini
- Elan Pharmaceuticals Inc., South San Francisco, CA 94080
| | | | - Eric K. Richfield
- Department of Pathology and Lab Medicine Robert Wood Johnson Medical School (RWJMS), University of Medicine and Dentistry New Jersey (UMDNJ), Piscataway, NJ 08854
- Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, NJ 08854
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46
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NACP-Rep1 relates to Beck Depression Inventory scores in healthy humans. J Mol Neurosci 2011; 44:41-7. [PMID: 21271299 DOI: 10.1007/s12031-011-9493-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 01/11/2011] [Indexed: 10/18/2022]
Abstract
Alpha-synuclein (SNCA) is associated with a range of psychiatric diseases including neurodegeneration, alcohol craving, and depression. It regulates cellular homeostasis by virtue of its ability to interfere in dopaminergic, serotonergic, and noradrenergic pathways. To date, it is unclear whether the previously described association between SNCA and depressive symptomatology is limited to females with eating disorders or whether it could be extended to include healthy individuals. We included 105 women and 108 men. Genetic data and mRNA expression analyses were drawn from peripheral blood and the severity of depressive symptoms was quantified by the Beck's Depression Inventory (BDI). We found a significant association between the NACP-Rep1 length polymorphism and the BDI score (p = 0.004). Moreover, there was a significant gender dimorphism regarding mRNA expression of SNCA (p = 0.011). Our analysis revealed no further association between the In4 polymorphism or between the mRNA expression of SNCA and the BDI score. Since this investigation was limited to healthy individuals, conclusions concerning depression according to ICD-10 or DSM-IV cannot be drawn. The reported results may contribute to a better understanding of the molecular mechanisms linked to depressive symptoms.
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47
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Lin Z, Canales JJ, Björgvinsson T, Thomsen MM, Qu H, Liu QR, Torres GE, Caine SB. Monoamine transporters: vulnerable and vital doorkeepers. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:1-46. [PMID: 21199769 PMCID: PMC3321928 DOI: 10.1016/b978-0-12-385506-0.00001-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transporters of dopamine, serotonin, and norepinephrine have been empirically used as medication targets for several mental illnesses in the last decades. These protein-targeted medications are effective only for subpopulations of patients with transporter-related brain disorders. Since the cDNA clonings in early 1990s, molecular studies of these transporters have revealed a wealth of information about the transporters' structure-activity relationship (SAR), neuropharmacology, cell biology, biochemistry, pharmacogenetics, and the diseases related to the human genes encoding these transporters among related regulators. Such new information creates a unique opportunity to develop transporter-specific medications based on SAR, mRNA, DNA, and perhaps transporter trafficking regulation for a number of highly relevant diseases including substance abuse, depression, schizophrenia, and Parkinson's disease.
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Affiliation(s)
- Zhicheng Lin
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Juan J. Canales
- Department of Psychology, Behavioural Neuroscience, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Thröstur Björgvinsson
- Behavioral Health Partial Hospital and Psychology Internship Programs, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA
| | - Morgane M. Thomsen
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Hong Qu
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University. Beijing, 100871 China
| | - Qing-Rong Liu
- Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Gonzalo E. Torres
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - S. Barak Caine
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
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Fjorback AW, Sundbye S, Dächsel JC, Sinning S, Wiborg O, Jensen PH. P25α / TPPP expression increases plasma membrane presentation of the dopamine transporter and enhances cellular sensitivity to dopamine toxicity. FEBS J 2010; 278:493-505. [PMID: 21182589 DOI: 10.1111/j.1742-4658.2010.07970.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Parkinson's disease is characterized by preferential degeneration of the dopamine-producing neurons of the brain stem substantia nigra. Imbalances between mechanisms governing dopamine transport across the plasma membrane and cellular storage vesicles increase the level of toxic pro-oxidative cytosolic dopamine. The microtubule-stabilizing protein p25α accumulates in dopaminergic neurons in Parkinson's disease. We hypothesized that p25α modulates the subcellular localization of the dopamine transporter via effects on sorting vesicles, and thereby indirectly affects its cellular activity. Here we show that co-expression of the dopamine transporter with p25α in HEK-293-MSR cells increases dopamine uptake via increased plasma membrane presentation of the transporter. No direct interaction between p25α and the dopamine transporter was demonstrated, but they co-fractionated during subcellular fractionation of brain tissue from striatum, and direct binding of p25α peptides to brain vesicles was demonstrated. Truncations of the p25α peptide revealed that the requirement for stimulating dopamine uptake is located in the central core and were similar to those required for vesicle binding. Co-expression of p25α and the dopamine transporter in HEK-293-MSR cells sensitized them to the toxicity of extracellular dopamine. Neuronal expression of p25α thus holds the potential to sensitize the cells toward dopamine and toxins carried by the dopamine transporter.
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Affiliation(s)
- Anja W Fjorback
- Centre for Psychiatric Research, Aarhus University Hospital, Denmark
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49
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Mercado CP, Kilic F. Molecular mechanisms of SERT in platelets: regulation of plasma serotonin levels. Mol Interv 2010; 10:231-41. [PMID: 20729489 DOI: 10.1124/mi.10.4.6] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The serotonin transporter (SERT) on platelets is a primary mechanism for serotonin (5HT) uptake from the blood plasma. Alteration in plasma 5HT level is associated with a number of cardiovascular diseases and disorders. Therefore, the regulation of the transporter's activity represents a key mechanism to stabilize the concentration of plasma 5HT. There is a biphasic relationship between plasma 5HT elevation, loss of surface SERT, and depletion of platelet 5HT. Specifically, in platelets, plasma membrane SERT levels and platelet 5HT uptake initially rise as plasma 5HT levels are increased but then fall below normal as the plasma 5HT level continues to rise. Therefore, we propose that elevated plasma 5HT limits its own uptake in platelets by down-regulating SERT as well as modifying the characteristics of SERT partners in the membrane trafficking pathway. This review will summarize current findings regarding the biochemical mechanisms by which elevated 5HT downregulates the expression of SERT on the platelet membrane. Intriguing aspects of this regulation include the intracellular interplay of SERT with the small G protein Rab4 and the concerted 5HT-mediated phosphorylation of vimentin.
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Affiliation(s)
- Charles P Mercado
- Department of Biochemistry and Molecular Biology College of Medicine, The University of Arkansas for Medical Sciences Little Rock, Arkansas 72205, USA
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50
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Kudryavtseva NN, Bondar NP, Boyarskikh UA, Filipenko ML. Snca and Bdnf gene expression in the VTA and raphe nuclei of midbrain in chronically victorious and defeated male mice. PLoS One 2010; 5:e14089. [PMID: 21124898 PMCID: PMC2990715 DOI: 10.1371/journal.pone.0014089] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 10/21/2010] [Indexed: 12/18/2022] Open
Abstract
Background Alpha-synuclein (α-Syn) is a small neuronal protein that has been found to be expressed throughout the brain. It has been shown that α-Syn regulates the homeostasis of monoamine neurotransmitters and is involved in various degenerative and affective disorders. There is indication that α-Syn may regulate expression of the brain-derived neurotropic factor (BDNF) which plays an important role in the mood disorders. Methodology/Principal Findings The study aimed to analyze the mRNA levels of Snca and Bdnf genes in the ventral tegmental area (VTA) and raphe nuclei of the midbrain in male mice that had each won or defeated 20 encounters (20-time winners and 20-time losers, respectively) in daily agonistic interactions. Groups of animals that had the same winning and losing track record followed by a no-fight period for 14 days (no-fighting winners and no-fighting losers) were also studied. Snca mRNA levels were increased in the raphe nuclei in the 20-time losers and in the VTA of the 20-time winners. After no-fight period Snca mRNA levels decreased in both groups. Snca mRNA levels were similar to the control level in the VTA of the 20-time losers and in the raphe nuclei of the 20-time winners. However Snca gene expression increased in these areas in the no-fighting winners and no-fighting losers in comparison with respective mRNA levels in animals before no-fight period. Bdnf mRNA levels increased in VTA of 20-time winners. Significant positive correlations were found between the mRNA levels of Snca and Bdnf genes in the raphe nuclei. Conclusions/Significance Social experience affects Snca gene expression depending on brain areas and functional activity of monoaminergic systems in chronically victorious or defeated mice. These findings may be useful for understanding the mechanisms of forming different alpha-synucleinopathies.
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