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Björklund A, Mattsson B. The AAV-α-Synuclein Model of Parkinson's Disease: An Update. JOURNAL OF PARKINSON'S DISEASE 2024:JPD240207. [PMID: 39031386 DOI: 10.3233/jpd-240207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2024]
Abstract
Targeted delivery of α-synuclein using AAV vectors has over the two decades since its introduction developed into a versatile tool for modeling different aspects of synucleinopathy, mimicking those seen in Parkinson's disease and related Lewy body disorders. The viral vector approach to disease modeling is attractive in that the expression of α-synuclein, wild-type or mutated, can be confined to defined anatomical structures and targeted to selected cell populations using either cell-type specific promoter constructs or different natural or engineered AAV serotypes. AAV-α-synuclein was initially used to model progressive α-synuclein pathology in nigral dopamine neurons, and, like the standard 6-OHDA model, it has most commonly been applied unilaterally, using the non-injected side as a reference and control. In recent years, however, the AAV-α-synuclein model has become more widely used to induce Parkinson-like synuclein pathology in other relevant neuronal systems, such as the brainstem noradrenergic and serotonergic neurons, the vagal motor neurons, as well as in oligodendrocytes, the prime target relevant to the pathology seen in multiple system atrophy. The purpose of this review is to give an overview of the progress made in the use of the AAV-α-synuclein model over the last two decades and summarize the state-of-the art in the use of the AAV-α-synuclein model for disease modeling in rats and mice.
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Affiliation(s)
- Anders Björklund
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Bengt Mattsson
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
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2
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Wilson EL, Yu Y, Leal NS, Woodward JA, Patikas N, Morris JL, Field SF, Plumbly W, Paupe V, Chowdhury SR, Antrobus R, Lindop GE, Adia YM, Loh SHY, Prudent J, Martins LM, Metzakopian E. Genome-wide CRISPR/Cas9 screen shows that loss of GET4 increases mitochondria-endoplasmic reticulum contact sites and is neuroprotective. Cell Death Dis 2024; 15:203. [PMID: 38467609 PMCID: PMC10928201 DOI: 10.1038/s41419-024-06568-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/13/2024]
Abstract
Organelles form membrane contact sites between each other, allowing for the transfer of molecules and signals. Mitochondria-endoplasmic reticulum (ER) contact sites (MERCS) are cellular subdomains characterized by close apposition of mitochondria and ER membranes. They have been implicated in many diseases, including neurodegenerative, metabolic, and cardiac diseases. Although MERCS have been extensively studied, much remains to be explored. To uncover novel regulators of MERCS, we conducted a genome-wide, flow cytometry-based screen using an engineered MERCS reporter cell line. We found 410 genes whose downregulation promotes MERCS and 230 genes whose downregulation decreases MERCS. From these, 29 genes were selected from each population for arrayed screening and 25 were validated from the high population and 13 from the low population. GET4 and BAG6 were highlighted as the top 2 genes that upon suppression increased MERCS from both the pooled and arrayed screens, and these were subjected to further investigation. Multiple microscopy analyses confirmed that loss of GET4 or BAG6 increased MERCS. GET4 and BAG6 were also observed to interact with the known MERCS proteins, inositol 1,4,5-trisphosphate receptors (IP3R) and glucose-regulated protein 75 (GRP75). In addition, we found that loss of GET4 increased mitochondrial calcium uptake upon ER-Ca2+ release and mitochondrial respiration. Finally, we show that loss of GET4 rescues motor ability, improves lifespan and prevents neurodegeneration in a Drosophila model of Alzheimer's disease (Aβ42Arc). Together, these results suggest that GET4 is involved in decreasing MERCS and that its loss is neuroprotective.
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Affiliation(s)
- Emma L Wilson
- UK Dementia Research Institute, University of Cambridge, Clifford Albutt building, Cambridge biomedical campus, Cambridge, CB2 0AH, UK
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Yizhou Yu
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Nuno S Leal
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - James A Woodward
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Nikolaos Patikas
- UK Dementia Research Institute, University of Cambridge, Clifford Albutt building, Cambridge biomedical campus, Cambridge, CB2 0AH, UK
| | - Jordan L Morris
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Sarah F Field
- UK Dementia Research Institute, University of Cambridge, Clifford Albutt building, Cambridge biomedical campus, Cambridge, CB2 0AH, UK
| | - William Plumbly
- UK Dementia Research Institute, University of Cambridge, Clifford Albutt building, Cambridge biomedical campus, Cambridge, CB2 0AH, UK
| | - Vincent Paupe
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Suvagata R Chowdhury
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Rd, Cambridge, CB2 0XY, UK
| | - Georgina E Lindop
- Cambridge Advanced Imaging Centre, University of Cambridge, Anatomy Building, Downing Site, Cambridge, CB2 3DY, UK
| | - Yusuf M Adia
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Samantha H Y Loh
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Julien Prudent
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
| | - L Miguel Martins
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Road, Cambridge, CB2 1QR, UK.
| | - Emmanouil Metzakopian
- UK Dementia Research Institute, University of Cambridge, Clifford Albutt building, Cambridge biomedical campus, Cambridge, CB2 0AH, UK.
- bit bio, The Dorothy Hodgkin Building, Babraham Research Campus, Cambridge, CB22 3FH, UK.
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3
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Zhou L, Li Y, Wang M, Han W, Chen Q, Zhang J, Sun B, Fan Y. Disruption of α-Synuclein proteostasis in the striatum and midbrain of long-term ovariectomized female mice. Neuroscience 2023:S0306-4522(23)00224-5. [PMID: 37257555 DOI: 10.1016/j.neuroscience.2023.05.013] [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: 01/13/2023] [Revised: 05/09/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023]
Abstract
Epidemiological studies have demonstrated that women are less susceptible to Parkinson's disease (PD) than men. Estrogen exposure is hypothesized to confer protection against dopaminergic neuronal loss in patients with PD. Although the accumulation and propagation of α-synuclein (α-Syn) are closely linked to the clinical progression of PD, no relevant research has examined whether α-Syn proteostasis in the brain is altered in women after menopause. In this study, we established long-term ovariectomized (OVX) mice to simulate late post-menopause and investigated the expression and aggregation of α-Syn following the ovariectomy procedure. We observed that the OVX mice exhibited a significant increase in the expression and aggregation of α-Syn in the striatum and midbrain accompanied by impaired motor performance at 3 months after ovariectomy. The accumulation of α-Syn did not result in a significant loss of nigral dopaminergic neurons but did enhance autophagy and neuroglial activation. These findings imply that menopause may disrupt α-Syn proteostasis and exacerbate the accumulation of α-Syn in the basal ganglia circuit.
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Affiliation(s)
- Linfeng Zhou
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Yun Li
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Min Wang
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Wenjing Han
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Qiang Chen
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Ji Zhang
- Division of Clinical Pharmacy, Department of Pharmacy, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Bo Sun
- Department of Neurology, the Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu 223300, China; Department of Neurology, the Huaian Clinical College of Xuzhou Medical University, Huai'an, Jiangsu 223300, China.
| | - Yi Fan
- Neuroprotective Drug Discovery Center of Nanjing Medical University, Department of Pharmacology, Nanjing Medical University, Nanjing, China.
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4
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Lunev E, Karan A, Egorova T, Bardina M. Adeno-Associated Viruses for Modeling Neurological Diseases in Animals: Achievements and Prospects. Biomedicines 2022; 10:biomedicines10051140. [PMID: 35625877 PMCID: PMC9139062 DOI: 10.3390/biomedicines10051140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/13/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
Adeno-associated virus (AAV) vectors have become an attractive tool for efficient gene transfer into animal tissues. Extensively studied as the vehicles for therapeutic constructs in gene therapy, AAVs are also applied for creating animal models of human genetic disorders. Neurological disorders are challenging to model in laboratory animals by transgenesis or genome editing, at least partially due to the embryonic lethality and the timing of the disease onset. Therefore, gene transfer with AAV vectors provides a more flexible option for simulating genetic neurological disorders. Indeed, the design of the AAV expression construct allows the reproduction of various disease-causing mutations, and also drives neuron-specific expression. The natural and newly created AAV serotypes combined with various delivery routes enable differentially targeting neuronal cell types and brain areas in vivo. Moreover, the same viral vector can be used to reproduce the main features of the disorder in mice, rats, and large laboratory animals such as non-human primates. The current review demonstrates the general principles for the development and use of AAVs in modeling neurological diseases. The latest achievements in AAV-mediated modeling of the common (e.g., Alzheimer’s disease, Parkinson’s disease, ataxias, etc.) and ultra-rare disorders affecting the central nervous system are described. The use of AAVs to create multiple animal models of neurological disorders opens opportunities for studying their mechanisms, understanding the main pathological features, and testing therapeutic approaches.
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Affiliation(s)
- Evgenii Lunev
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Marlin Biotech LLC, 354340 Sochi, Russia; (A.K.); (T.E.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Correspondence: (E.L.); (M.B.)
| | - Anna Karan
- Marlin Biotech LLC, 354340 Sochi, Russia; (A.K.); (T.E.)
| | - Tatiana Egorova
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Marlin Biotech LLC, 354340 Sochi, Russia; (A.K.); (T.E.)
| | - Maryana Bardina
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Marlin Biotech LLC, 354340 Sochi, Russia; (A.K.); (T.E.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
- Correspondence: (E.L.); (M.B.)
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5
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Lama J, Buhidma Y, Fletcher E, Duty S. Animal models of Parkinson's disease: a guide to selecting the optimal model for your research. Neuronal Signal 2021; 5:NS20210026. [PMID: 34956652 PMCID: PMC8661507 DOI: 10.1042/ns20210026] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 12/18/2022] Open
Abstract
Parkinson's disease (PD) is a complex, multisystem disorder characterised by α-synuclein (SNCA) pathology, degeneration of nigrostriatal dopaminergic neurons, multifactorial pathogenetic mechanisms and expression of a plethora of motor and non-motor symptoms. Animal models of PD have already been instructive in helping us unravel some of these aspects. However, much remains to be discovered, requiring continued interrogation by the research community. In contrast with the situation for many neurological disorders, PD benefits from of a wide range of available animal models (pharmacological, toxin, genetic and α-synuclein) but this makes selection of the optimal one for a given study difficult. This is especially so when a study demands a model that displays a specific combination of features. While many excellent reviews of animal models already exist, this review takes a different approach with the intention of more readily informing this decision-making process. We have considered each feature of PD in turn - aetiology, pathology, pathogenesis, motor dysfunctions and non-motor symptoms (NMS) - highlighting those animal models that replicate each. By compiling easily accessible tables and a summary figure, we aim to provide the reader with a simple, go-to resource for selecting the optimal animal model of PD to suit their research needs.
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Affiliation(s)
- Joana Lama
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Wolfson Centre for Age Related Diseases, Wolfson Wing, Hodgkin Building, Guy’s Campus, London SE1 1UL, U.K
| | - Yazead Buhidma
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Wolfson Centre for Age Related Diseases, Wolfson Wing, Hodgkin Building, Guy’s Campus, London SE1 1UL, U.K
| | - Edward J.R. Fletcher
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Wolfson Centre for Age Related Diseases, Wolfson Wing, Hodgkin Building, Guy’s Campus, London SE1 1UL, U.K
| | - Susan Duty
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Wolfson Centre for Age Related Diseases, Wolfson Wing, Hodgkin Building, Guy’s Campus, London SE1 1UL, U.K
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Kelly R, Cairns AG, Ådén J, Almqvist F, Bemelmans AP, Brouillet E, Patton T, McKernan DP, Dowd E. The Small Molecule Alpha-Synuclein Aggregator, FN075, Enhances Alpha-Synuclein Pathology in Subclinical AAV Rat Models. Biomolecules 2021; 11:1685. [PMID: 34827685 PMCID: PMC8615715 DOI: 10.3390/biom11111685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/03/2021] [Accepted: 11/09/2021] [Indexed: 12/13/2022] Open
Abstract
Animal models of Parkinson's disease, in which the human α-synuclein transgene is overexpressed in the nigrostriatal pathway using viral vectors, are widely considered to be the most relevant models of the human condition. However, although highly valid, these models have major limitations related to reliability and variability, with many animals exhibiting pronounced α-synuclein expression failing to demonstrate nigrostriatal neurodegeneration or motor dysfunction. Therefore, the aim of this study was to determine if sequential intra-nigral administration of AAV-α-synuclein followed by the small α-synuclein aggregating molecule, FN075, would enhance or precipitate the associated α-synucleinopathy, nigrostriatal pathology and motor dysfunction in subclinical models. Rats were given unilateral intra-nigral injections of AAV-α-synuclein (either wild-type or A53T mutant) followed four weeks later by a unilateral intra-nigral injection of FN075, after which they underwent behavioral testing for lateralized motor functionality until they were sacrificed for immunohistological assessment at 20 weeks after AAV administration. In line with expectations, both of the AAV vectors induced widespread overexpression of human α-synuclein in the substantia nigra and striatum. Sequential administration of FN075 significantly enhanced the α-synuclein pathology with increased density and accumulation of the pathological form of the protein phosphorylated at serine 129 (pS129-α-synuclein). However, despite this enhanced α-synuclein pathology, FN075 did not precipitate nigrostriatal degeneration or motor dysfunction in these subclinical AAV models. In conclusion, FN075 holds significant promise as an approach to enhancing the α-synuclein pathology in viral overexpression models, but further studies are required to determine if alternative administration regimes for this molecule could improve the reliability and variability in these models.
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Affiliation(s)
- Rachel Kelly
- Pharmacology & Therapeutics and Galway Neuroscience Centre, National University of Ireland Galway, H91 W5P7 Galway, Ireland; (R.K.); (T.P.); (D.P.M.)
| | - Andrew G. Cairns
- Department of Chemistry, Umeå University, 901 87 Umeå, Sweden; (A.G.C.); (J.Å.); (F.A.)
| | - Jörgen Ådén
- Department of Chemistry, Umeå University, 901 87 Umeå, Sweden; (A.G.C.); (J.Å.); (F.A.)
| | - Fredrik Almqvist
- Department of Chemistry, Umeå University, 901 87 Umeå, Sweden; (A.G.C.); (J.Å.); (F.A.)
| | - Alexis-Pierre Bemelmans
- Université Paris-Saclay, CEA, CNRS, Laboratoire des Maladies Neurodégénératives, MIRCen, F-92265 Fontenay-aux-Roses, France; (A.-P.B.); (E.B.)
| | - Emmanuel Brouillet
- Université Paris-Saclay, CEA, CNRS, Laboratoire des Maladies Neurodégénératives, MIRCen, F-92265 Fontenay-aux-Roses, France; (A.-P.B.); (E.B.)
| | - Tommy Patton
- Pharmacology & Therapeutics and Galway Neuroscience Centre, National University of Ireland Galway, H91 W5P7 Galway, Ireland; (R.K.); (T.P.); (D.P.M.)
| | - Declan P. McKernan
- Pharmacology & Therapeutics and Galway Neuroscience Centre, National University of Ireland Galway, H91 W5P7 Galway, Ireland; (R.K.); (T.P.); (D.P.M.)
| | - Eilís Dowd
- Pharmacology & Therapeutics and Galway Neuroscience Centre, National University of Ireland Galway, H91 W5P7 Galway, Ireland; (R.K.); (T.P.); (D.P.M.)
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Mehra S, Gadhe L, Bera R, Sawner AS, Maji SK. Structural and Functional Insights into α-Synuclein Fibril Polymorphism. Biomolecules 2021; 11:1419. [PMID: 34680054 PMCID: PMC8533119 DOI: 10.3390/biom11101419] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/21/2022] Open
Abstract
Abnormal accumulation of aggregated α-synuclein (α-Syn) is seen in a variety of neurodegenerative diseases, including Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy body (DLB), Parkinson's disease dementia (PDD), and even subsets of Alzheimer's disease (AD) showing Lewy-body-like pathology. These synucleinopathies exhibit differences in their clinical and pathological representations, reminiscent of prion disorders. Emerging evidence suggests that α-Syn self-assembles and polymerizes into conformationally diverse polymorphs in vitro and in vivo, similar to prions. These α-Syn polymorphs arising from the same precursor protein may exhibit strain-specific biochemical properties and the ability to induce distinct pathological phenotypes upon their inoculation in animal models. In this review, we discuss clinical and pathological variability in synucleinopathies and several aspects of α-Syn fibril polymorphism, including the existence of high-resolution molecular structures and brain-derived strains. The current review sheds light on the recent advances in delineating the structure-pathogenic relationship of α-Syn and how diverse α-Syn molecular polymorphs contribute to the existing clinical heterogeneity in synucleinopathies.
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Affiliation(s)
- Surabhi Mehra
- Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai 400076, India; (L.G.); (R.B.); (A.S.S.)
| | | | | | | | - Samir K. Maji
- Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai 400076, India; (L.G.); (R.B.); (A.S.S.)
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Dagra A, Miller DR, Lin M, Gopinath A, Shaerzadeh F, Harris S, Sorrentino ZA, Støier JF, Velasco S, Azar J, Alonge AR, Lebowitz JJ, Ulm B, Bu M, Hansen CA, Urs N, Giasson BI, Khoshbouei H. α-Synuclein-induced dysregulation of neuronal activity contributes to murine dopamine neuron vulnerability. NPJ Parkinsons Dis 2021; 7:76. [PMID: 34408150 PMCID: PMC8373893 DOI: 10.1038/s41531-021-00210-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 07/09/2021] [Indexed: 02/07/2023] Open
Abstract
Pathophysiological damages and loss of function of dopamine neurons precede their demise and contribute to the early phases of Parkinson's disease. The presence of aberrant intracellular pathological inclusions of the protein α-synuclein within ventral midbrain dopaminergic neurons is one of the cardinal features of Parkinson's disease. We employed molecular biology, electrophysiology, and live-cell imaging to investigate how excessive α-synuclein expression alters multiple characteristics of dopaminergic neuronal dynamics and dopamine transmission in cultured dopamine neurons conditionally expressing GCaMP6f. We found that overexpression of α-synuclein in mouse (male and female) dopaminergic neurons altered neuronal firing properties, calcium dynamics, dopamine release, protein expression, and morphology. Moreover, prolonged exposure to the D2 receptor agonist, quinpirole, rescues many of the alterations induced by α-synuclein overexpression. These studies demonstrate that α-synuclein dysregulation of neuronal activity contributes to the vulnerability of dopaminergic neurons and that modulation of D2 receptor activity can ameliorate the pathophysiology. These findings provide mechanistic insights into the insidious changes in dopaminergic neuronal activity and neuronal loss that characterize Parkinson's disease progression with significant therapeutic implications.
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Affiliation(s)
- Abeer Dagra
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Douglas R. Miller
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Min Lin
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Adithya Gopinath
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Fatemeh Shaerzadeh
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Sharonda Harris
- grid.15276.370000 0004 1936 8091Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL USA
| | - Zachary A. Sorrentino
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Jonatan Fullerton Støier
- grid.5254.60000 0001 0674 042XMolecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sophia Velasco
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Janelle Azar
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Adetola R. Alonge
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Joseph J. Lebowitz
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Brittany Ulm
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Mengfei Bu
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Carissa A. Hansen
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Nikhil Urs
- grid.15276.370000 0004 1936 8091Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL USA
| | - Benoit I. Giasson
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
| | - Habibeh Khoshbouei
- grid.15276.370000 0004 1936 8091Department of Neuroscience, University of Florida, Gainesville, FL USA
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9
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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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10
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Miller DR, Guenther DT, Maurer AP, Hansen CA, Zalesky A, Khoshbouei H. Dopamine Transporter Is a Master Regulator of Dopaminergic Neural Network Connectivity. J Neurosci 2021; 41:5453-5470. [PMID: 33980544 PMCID: PMC8221606 DOI: 10.1523/jneurosci.0223-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/19/2021] [Accepted: 05/01/2021] [Indexed: 12/13/2022] Open
Abstract
Dopaminergic neurons of the substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) exhibit spontaneous firing activity. The dopaminergic neurons in these regions have been shown to exhibit differential sensitivity to neuronal loss and psychostimulants targeting dopamine transporter. However, it remains unclear whether these regional differences scale beyond individual neuronal activity to regional neuronal networks. Here, we used live-cell calcium imaging to show that network connectivity greatly differs between SNC and VTA regions with higher incidence of hub-like neurons in the VTA. Specifically, the frequency of hub-like neurons was significantly lower in SNC than in the adjacent VTA, consistent with the interpretation of a lower network resilience to SNC neuronal loss. We tested this hypothesis, in DAT-cre/loxP-GCaMP6f mice of either sex, when activity of an individual dopaminergic neuron is suppressed, through whole-cell patch clamp electrophysiology, in either SNC or VTA networks. Neuronal loss in the SNC increased network clustering, whereas the larger number of hub-neurons in the VTA overcompensated by decreasing network clustering in the VTA. We further show that network properties are regulatable via a dopamine transporter but not a D2 receptor dependent mechanism. Our results demonstrate novel regulatory mechanisms of functional network topology in dopaminergic brain regions.SIGNIFICANCE STATEMENT In this work, we begin to untangle the differences in complex network properties between the substantia nigra pars compacta (SNC) and VTA, that may underlie differential sensitivity between regions. The methods and analysis employed provide a springboard for investigations of network topology in multiple deep brain structures and disorders.
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Affiliation(s)
- Douglas R Miller
- Department of Neuroscience, University of Florida, Gainesville, Florida
| | - Dylan T Guenther
- Department of Neuroscience, University of Florida, Gainesville, Florida
| | - Andrew P Maurer
- Department of Neuroscience, University of Florida, Gainesville, Florida
| | - Carissa A Hansen
- Department of Neuroscience, University of Florida, Gainesville, Florida
| | - Andrew Zalesky
- Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Melbourne, Victoria 3010, Australia
- Department of Biomedical Engineering, Melbourne School of Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
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11
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Needs HI, Protasoni M, Henley JM, Prudent J, Collinson I, Pereira GC. Interplay between Mitochondrial Protein Import and Respiratory Complexes Assembly in Neuronal Health and Degeneration. Life (Basel) 2021; 11:432. [PMID: 34064758 PMCID: PMC8151517 DOI: 10.3390/life11050432] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/27/2021] [Accepted: 05/02/2021] [Indexed: 12/14/2022] Open
Abstract
The fact that >99% of mitochondrial proteins are encoded by the nuclear genome and synthesised in the cytosol renders the process of mitochondrial protein import fundamental for normal organelle physiology. In addition to this, the nuclear genome comprises most of the proteins required for respiratory complex assembly and function. This means that without fully functional protein import, mitochondrial respiration will be defective, and the major cellular ATP source depleted. When mitochondrial protein import is impaired, a number of stress response pathways are activated in order to overcome the dysfunction and restore mitochondrial and cellular proteostasis. However, prolonged impaired mitochondrial protein import and subsequent defective respiratory chain function contributes to a number of diseases including primary mitochondrial diseases and neurodegeneration. This review focuses on how the processes of mitochondrial protein translocation and respiratory complex assembly and function are interlinked, how they are regulated, and their importance in health and disease.
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Affiliation(s)
- Hope I. Needs
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
| | - Margherita Protasoni
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
| | - Jeremy M. Henley
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
- Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Julien Prudent
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
| | - Ian Collinson
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
| | - Gonçalo C. Pereira
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
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12
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Neurons and Glia Interplay in α-Synucleinopathies. Int J Mol Sci 2021; 22:ijms22094994. [PMID: 34066733 PMCID: PMC8125822 DOI: 10.3390/ijms22094994] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/29/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
Accumulation of the neuronal presynaptic protein alpha-synuclein within proteinaceous inclusions represents the key histophathological hallmark of a spectrum of neurodegenerative disorders, referred to by the umbrella term a-synucleinopathies. Even though alpha-synuclein is expressed predominantly in neurons, pathological aggregates of the protein are also found in the glial cells of the brain. In Parkinson's disease and dementia with Lewy bodies, alpha-synuclein accumulates mainly in neurons forming the Lewy bodies and Lewy neurites, whereas in multiple system atrophy, the protein aggregates mostly in the glial cytoplasmic inclusions within oligodendrocytes. In addition, astrogliosis and microgliosis are found in the synucleinopathy brains, whereas both astrocytes and microglia internalize alpha-synuclein and contribute to the spread of pathology. The mechanisms underlying the pathological accumulation of alpha-synuclein in glial cells that under physiological conditions express low to non-detectable levels of the protein are an area of intense research. Undoubtedly, the presence of aggregated alpha-synuclein can disrupt glial function in general and can contribute to neurodegeneration through numerous pathways. Herein, we summarize the current knowledge on the role of alpha-synuclein in both neurons and glia, highlighting the contribution of the neuron-glia connectome in the disease initiation and progression, which may represent potential therapeutic target for a-synucleinopathies.
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13
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Olson KE, Namminga KL, Lu Y, Thurston MJ, Schwab AD, de Picciotto S, Tse SW, Walker W, Iacovelli J, Small C, Wipke BT, Mosley RL, Huang E, Gendelman HE. Granulocyte-macrophage colony-stimulating factor mRNA and Neuroprotective Immunity in Parkinson's disease. Biomaterials 2021; 272:120786. [PMID: 33839625 PMCID: PMC8382980 DOI: 10.1016/j.biomaterials.2021.120786] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 02/06/2023]
Abstract
Restoring numbers and function of regulatory T cells (Tregs) is a novel therapeutic strategy for neurodegenerative disorders. Whether Treg function is boosted by adoptive cell transfer, pharmaceuticals, or immune modulators, the final result is a robust anti-inflammatory and neuronal sparing response. Herein, a newly developed lipid nanoparticle (LNP) containing mRNA encoding granulocyte-macrophage colony-stimulating factor (Gm-csf mRNA) was developed to peripherally induce Tregs and used for treatment in preclinical Parkinson's disease (PD) models. Administration of Gm-csf mRNA to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice and rats overexpressing alpha-synuclein produced dose-dependent increases in plasma GM-CSF levels and peripheral CD4+CD25+FoxP3+ Treg populations. This upregulation paralleled nigrostriatal neuroprotection, upregulated immunosuppression-associated mRNAs that led to the detection of a treatment-induced CD4+ T cell population, and decreased reactive microgliosis. The current findings strengthen prior works utilizing immune modulation by harnessing Gm-csf mRNA to augment adaptive immune function by employing a new delivery platform to treat PD and potentially other neurodegenerative disorders.
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Affiliation(s)
- Katherine E Olson
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Krista L Namminga
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yaman Lu
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Mackenzie J Thurston
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Aaron D Schwab
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | | | | | | | | | | | | | - R Lee Mosley
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Eric Huang
- Moderna, Inc., Cambridge, MA, 02139, USA
| | - Howard E Gendelman
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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14
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Comparison of the expression and toxicity of AAV2/9 carrying the human A53T α-synuclein gene in presence or absence of WPRE. Heliyon 2021; 7:e06302. [PMID: 33665452 PMCID: PMC7903312 DOI: 10.1016/j.heliyon.2021.e06302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/25/2020] [Accepted: 02/12/2021] [Indexed: 12/15/2022] Open
Abstract
Woodchuck Hepatitis Virus Post-transcriptional Regulatory Element (WPRE) is thought to enhance transgene expression of target genes delivered by adeno-associated viral (AAV) vectors. This study assessed the protein expression of α-synuclein, phosphorylated α-synuclein at Serine 129, extent of nigrostriatal degeneration as well as subsequent behavioral deficits induced by unilateral intranigral stereotactic injection in male adult C57BL/6J mice of an AAV2/9 expressing A53T human α-synuclein under the control of the synapsin promoter in presence or absence of the WPRE. The presence of WPRE enabled to achieve greater nigrostriatal degeneration and synucleinopathy which was concomitant with worsened forelimb use asymmetry. This work refines a mouse Parkinson's disease model in which anatomo-pathology is related to behavioral deficits.
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15
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Underwood R, Gannon M, Pathak A, Kapa N, Chandra S, Klop A, Yacoubian TA. 14-3-3 mitigates alpha-synuclein aggregation and toxicity in the in vivo preformed fibril model. Acta Neuropathol Commun 2021; 9:13. [PMID: 33413679 PMCID: PMC7792107 DOI: 10.1186/s40478-020-01110-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/19/2020] [Indexed: 12/26/2022] Open
Abstract
Alpha-synuclein (αsyn) is the key component of proteinaceous aggregates termed Lewy Bodies that pathologically define a group of disorders known as synucleinopathies, including Parkinson's Disease (PD) and Dementia with Lewy Bodies. αSyn is hypothesized to misfold and spread throughout the brain in a prion-like fashion. Transmission of αsyn necessitates the release of misfolded αsyn from one cell and the uptake of that αsyn by another, in which it can template the misfolding of endogenous αsyn upon cell internalization. 14-3-3 proteins are a family of highly expressed brain proteins that are neuroprotective in multiple PD models. We have previously shown that 14-3-3θ acts as a chaperone to reduce αsyn aggregation, cell-to-cell transmission, and neurotoxicity in the in vitro pre-formed fibril (PFF) model. In this study, we expanded our studies to test the impact of 14-3-3s on αsyn toxicity in the in vivo αsyn PFF model. We used both transgenic expression models and adenovirus associated virus (AAV)-mediated expression to examine whether 14-3-3 manipulation impacts behavioral deficits, αsyn aggregation, and neuronal counts in the PFF model. 14-3-3θ transgene overexpression in cortical and amygdala regions rescued social dominance deficits induced by PFFs at 6 months post injection, whereas 14-3-3 inhibition by transgene expression of the competitive 14-3-3 peptide inhibitor difopein in the cortex and amygdala accelerated social dominance deficits. The behavioral rescue by 14-3-3θ overexpression was associated with delayed αsyn aggregation induced by PFFs in these brain regions. Conversely, 14-3-3 inhibition by difopein in the cortex and amygdala accelerated αsyn aggregation and reduction in NECAB1-positive neuron counts induced by PFFs. 14-3-3θ overexpression by AAV in the substantia nigra (SN) also delayed αsyn aggregation in the SN and partially rescued PFF-induced reduction in tyrosine hydroxylase (TH)-positive dopaminergic cells in the SN. 14-3-3 inhibition in the SN accelerated nigral αsyn aggregation and enhanced PFF-induced reduction in TH-positive dopaminergic cells. These data indicate a neuroprotective role for 14-3-3θ against αsyn toxicity in vivo.
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Affiliation(s)
- Rachel Underwood
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Center for Neurodegenerative Disease Research, Perelman School of Medicine at the University of Pennsylvania, Maloney Building, 3rd Floor, 3600 Spruce Street, Philadelphia, PA 19104-2676 USA
| | - Mary Gannon
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Aneesh Pathak
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Navya Kapa
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Sidhanth Chandra
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Alyssa Klop
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Talene A. Yacoubian
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- Civitan International Research Center, Room 510A, 1719 Sixth Avenue South, Birmingham, AL 35294 USA
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16
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De Miranda BR, Rocha EM, Castro SL, Greenamyre JT. Protection from α-Synuclein induced dopaminergic neurodegeneration by overexpression of the mitochondrial import receptor TOM20. NPJ Parkinsons Dis 2020; 6:38. [PMID: 33293540 PMCID: PMC7722884 DOI: 10.1038/s41531-020-00139-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022] Open
Abstract
Dopaminergic neurons of the substantia nigra are selectively vulnerable to mitochondrial dysfunction, which is hypothesized to be an early and fundamental pathogenic mechanism in Parkinson's disease (PD). Mitochondrial function depends on the successful import of nuclear-encoded proteins, many of which are transported through the TOM20-TOM22 outer mitochondrial membrane import receptor machinery. Recent data suggests that post-translational modifications of α-synuclein promote its interaction with TOM20 at the outer mitochondrial membrane and thereby inhibit normal protein import, leading to dysfunction, and death of dopaminergic neurons. As such, preservation of mitochondrial import in the face of α-synuclein accumulation might be a strategy to prevent dopaminergic neurodegeneration, however, this is difficult to assess using current in vivo models of PD. To this end, we established an exogenous co-expression system, utilizing AAV2 vectors to overexpress human α-synuclein and TOM20, individually or together, in the adult Lewis rat substantia nigra to assess whether TOM20 overexpression attenuates α-synuclein-induced dopaminergic neurodegeneration. Twelve weeks after viral injection, we observed that AAV2-TOM20 expression was sufficient to prevent loss of nigral dopaminergic neurons caused by AAV2-αSyn overexpression. The observed TOM20-mediated dopaminergic neuron preservation appeared to be due, in part, to the rescued expression (and presumed import) of nuclear-encoded mitochondrial electron transport chain proteins that were inhibited by α-synuclein overexpression. In addition, TOM20 overexpression rescued the expression of the chaperone protein GRP75/mtHSP70/mortalin, a stress-response protein involved in α-synuclein-induced injury. Collectively, these data indicate that TOM20 expression prevents α-synuclein-induced mitochondrial dysfunction, which is sufficient to rescue dopaminergic neurons in the adult rat brain.
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Affiliation(s)
- Briana R De Miranda
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Emily M Rocha
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sandra L Castro
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
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17
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Troncoso-Escudero P, Sepulveda D, Pérez-Arancibia R, Parra AV, Arcos J, Grunenwald F, Vidal RL. On the Right Track to Treat Movement Disorders: Promising Therapeutic Approaches for Parkinson's and Huntington's Disease. Front Aging Neurosci 2020; 12:571185. [PMID: 33101007 PMCID: PMC7497570 DOI: 10.3389/fnagi.2020.571185] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/17/2020] [Indexed: 12/17/2022] Open
Abstract
Movement disorders are neurological conditions in which patients manifest a diverse range of movement impairments. Distinct structures within the basal ganglia of the brain, an area involved in movement regulation, are differentially affected for every disease. Among the most studied movement disorder conditions are Parkinson’s (PD) and Huntington’s disease (HD), in which the deregulation of the movement circuitry due to the loss of specific neuronal populations in basal ganglia is the underlying cause of motor symptoms. These symptoms are due to the loss principally of dopaminergic neurons of the substantia nigra (SN) par compacta and the GABAergic neurons of the striatum in PD and HD, respectively. Although these diseases were described in the 19th century, no effective treatment can slow down, reverse, or stop disease progression. Available pharmacological therapies have been focused on preventing or alleviating motor symptoms to improve the quality of life of patients, but these drugs are not able to mitigate the progressive neurodegeneration. Currently, considerable therapeutic advances have been achieved seeking a more efficacious and durable therapeutic effect. Here, we will focus on the new advances of several therapeutic approaches for PD and HD, starting with the available pharmacological treatments to alleviate the motor symptoms in both diseases. Then, we describe therapeutic strategies that aim to restore specific neuronal populations or their activity. Among the discussed strategies, the use of Neurotrophic factors (NTFs) and genetic approaches to prevent the neuronal loss in these diseases will be described. We will highlight strategies that have been evaluated in both Parkinson’s and Huntington’s patients, and also the ones with strong preclinical evidence. These current therapeutic techniques represent the most promising tools for the safe treatment of both diseases, specifically those aimed to avoid neuronal loss during disease progression.
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Affiliation(s)
- Paulina Troncoso-Escudero
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Denisse Sepulveda
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Rodrigo Pérez-Arancibia
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Alejandra V Parra
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Javiera Arcos
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Felipe Grunenwald
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
| | - Rene L Vidal
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health, and Metabolism, University of Chile, Santiago, Chile
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18
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Voskobiynyk Y, Roth JR, Cochran JN, Rush T, Carullo NVN, Mesina JS, Waqas M, Vollmer RM, Day JJ, McMahon LL, Roberson ED. Alzheimer's disease risk gene BIN1 induces Tau-dependent network hyperexcitability. eLife 2020; 9:e57354. [PMID: 32657270 PMCID: PMC7392604 DOI: 10.7554/elife.57354] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/12/2020] [Indexed: 12/30/2022] Open
Abstract
Genome-wide association studies identified the BIN1 locus as a leading modulator of genetic risk in Alzheimer's disease (AD). One limitation in understanding BIN1's contribution to AD is its unknown function in the brain. AD-associated BIN1 variants are generally noncoding and likely change expression. Here, we determined the effects of increasing expression of the major neuronal isoform of human BIN1 in cultured rat hippocampal neurons. Higher BIN1 induced network hyperexcitability on multielectrode arrays, increased frequency of synaptic transmission, and elevated calcium transients, indicating that increasing BIN1 drives greater neuronal activity. In exploring the mechanism of these effects on neuronal physiology, we found that BIN1 interacted with L-type voltage-gated calcium channels (LVGCCs) and that BIN1-LVGCC interactions were modulated by Tau in rat hippocampal neurons and mouse brain. Finally, Tau reduction prevented BIN1-induced network hyperexcitability. These data shed light on BIN1's neuronal function and suggest that it may contribute to Tau-dependent hyperexcitability in AD.
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Affiliation(s)
- Yuliya Voskobiynyk
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Jonathan R Roth
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - J Nicholas Cochran
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Travis Rush
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Nancy VN Carullo
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Jacob S Mesina
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Mohammad Waqas
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Rachael M Vollmer
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Jeremy J Day
- Department of Neurobiology, University of Alabama at BirminghamBirminghamUnited States
| | - Lori L McMahon
- Department of Cell, Developmental and Integrative Biology, University of Alabama at BirminghamBirminghamUnited States
| | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer’s Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at BirminghamBirminghamUnited States
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19
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Merchant KM, Cedarbaum JM, Brundin P, Dave KD, Eberling J, Espay AJ, Hutten SJ, Javidnia M, Luthman J, Maetzler W, Menalled L, Reimer AN, Stoessl AJ, Weiner DM. A Proposed Roadmap for Parkinson's Disease Proof of Concept Clinical Trials Investigating Compounds Targeting Alpha-Synuclein. JOURNAL OF PARKINSONS DISEASE 2020; 9:31-61. [PMID: 30400107 PMCID: PMC6398545 DOI: 10.3233/jpd-181471] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The convergence of human molecular genetics and Lewy pathology of Parkinson's disease (PD) have led to a robust, clinical-stage pipeline of alpha-synuclein (α-syn)-targeted therapies that have the potential to slow or stop the progression of PD and other synucleinopathies. To facilitate the development of these and earlier stage investigational molecules, the Michael J. Fox Foundation for Parkinson's Research convened a group of leaders in the field of PD research from academia and industry, the Alpha-Synuclein Clinical Path Working Group. This group set out to develop recommendations on preclinical and clinical research that can de-risk the development of α-syn targeting therapies. This consensus white paper provides a translational framework, from the selection of animal models and associated end-points to decision-driving biomarkers as well as considerations for the design of clinical proof-of-concept studies. It also identifies current gaps in our biomarker toolkit and the status of the discovery and validation of α-syn-associated biomarkers that could help fill these gaps. Further, it highlights the importance of the emerging digital technology to supplement the capture and monitoring of clinical outcomes. Although the development of disease-modifying therapies targeting α-syn face profound challenges, we remain optimistic that meaningful strides will be made soon toward the identification and approval of disease-modifying therapeutics targeting α-syn.
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Affiliation(s)
- Kalpana M Merchant
- Vincere Biosciences, Inc., and Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | | | - Patrik Brundin
- Van Andel Research Institute, Center for Neurodegenerative Science, Grand Rapids, MI, USA
| | - Kuldip D Dave
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA
| | - Jamie Eberling
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA
| | - Alberto J Espay
- UC Gardner Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, OH, USA
| | - Samantha J Hutten
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA
| | - Monica Javidnia
- Center for Health and Technology, University of Rochester Medical Center, Rochester, New York, USA
| | | | - Walter Maetzler
- Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Liliana Menalled
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA
| | - Alyssa N Reimer
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA
| | - A Jon Stoessl
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Center, University of British Columbia, Vancouver, BC, Canada
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20
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Lázaro DF, Outeiro TF. The Interplay Between Proteostasis Systems and Parkinson’s Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1233:223-236. [DOI: 10.1007/978-3-030-38266-7_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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21
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Arrant AE, Roth JR, Boyle NR, Kashyap SN, Hoffmann MQ, Murchison CF, Ramos EM, Nana AL, Spina S, Grinberg LT, Miller BL, Seeley WW, Roberson ED. Impaired β-glucocerebrosidase activity and processing in frontotemporal dementia due to progranulin mutations. Acta Neuropathol Commun 2019; 7:218. [PMID: 31870439 PMCID: PMC6929503 DOI: 10.1186/s40478-019-0872-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/17/2019] [Indexed: 01/29/2023] Open
Abstract
Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia. Most pathogenic GRN mutations result in progranulin haploinsufficiency, which is thought to cause frontotemporal dementia in GRN mutation carriers. Progranulin haploinsufficiency may drive frontotemporal dementia pathogenesis by disrupting lysosomal function, as patients with GRN mutations on both alleles develop the lysosomal storage disorder neuronal ceroid lipofuscinosis, and frontotemporal dementia patients with GRN mutations (FTD-GRN) also accumulate lipofuscin. The specific lysosomal deficits caused by progranulin insufficiency remain unclear, but emerging data indicate that progranulin insufficiency may impair lysosomal sphingolipid-metabolizing enzymes. We investigated the effects of progranulin insufficiency on sphingolipid-metabolizing enzymes in the inferior frontal gyrus of FTD-GRN patients using fluorogenic activity assays, biochemical profiling of enzyme levels and posttranslational modifications, and quantitative neuropathology. Of the enzymes studied, only β-glucocerebrosidase exhibited impairment in FTD-GRN patients. Brains from FTD-GRN patients had lower activity than controls, which was associated with lower levels of mature β-glucocerebrosidase protein and accumulation of insoluble, incompletely glycosylated β-glucocerebrosidase. Immunostaining revealed loss of neuronal β-glucocerebrosidase in FTD-GRN patients. To investigate the effects of progranulin insufficiency on β-glucocerebrosidase outside of the context of neurodegeneration, we investigated β-glucocerebrosidase activity in progranulin-insufficient mice. Brains from Grn-/- mice had lower β-glucocerebrosidase activity than wild-type littermates, which was corrected by AAV-progranulin gene therapy. These data show that progranulin insufficiency impairs β-glucocerebrosidase activity in the brain. This effect is strongest in neurons and may be caused by impaired β-glucocerebrosidase processing.
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Affiliation(s)
- Andrew E Arrant
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA.
- , 1825 University Blvd., SHEL 1106, Birmingham, AL, 35294, USA.
| | - Jonathan R Roth
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicholas R Boyle
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shreya N Kashyap
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Madelyn Q Hoffmann
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Charles F Murchison
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Eliana Marisa Ramos
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Alissa L Nana
- Department of Neurology, Memory & Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Salvatore Spina
- Department of Neurology, Memory & Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Lea T Grinberg
- Department of Neurology, Memory & Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce L Miller
- Department of Neurology, Memory & Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William W Seeley
- Department of Neurology, Memory & Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Erik D Roberson
- Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA.
- , 1825 University Blvd., SHEL 1110, Birmingham, AL, 35294, USA.
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22
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Quadri Z, Johnson N, Zamudio F, Miller A, Peters M, Smeltzer S, Hunt JB, Housley SB, Brown B, Kraner S, Norris CM, Nash K, Weeber E, Lee DC, Selenica MLB. Overexpression of human wtTDP-43 causes impairment in hippocampal plasticity and behavioral deficits in CAMKII-tTa transgenic mouse model. Mol Cell Neurosci 2019; 102:103418. [PMID: 31705957 DOI: 10.1016/j.mcn.2019.103418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 10/23/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022] Open
Abstract
AIMS The current study utilizes the adeno-associated viral gene transfer system in the CAMKIIα-tTA mouse model to overexpress human wild type TDP-43 (wtTDP-43) and α-synuclein (α-Syn) proteins. The co-existence of these proteins is evident in the pathology of neurodegenerative disorders such as frontotemporal lobar degeneration (FTLD), Parkinson disease (PD), and dementia with Lewy bodies (DLB). METHODS The novel bicistronic recombinant adeno-associated virus (rAAV) serotype 9 drives wtTDP-43 and α-Syn expression in the hippocampus via "TetO" CMV promoter. Behavior, electrophysiology, and biochemical and histological assays were used to validate neuropathology. RESULTS We report that overexpression of wtTDP-43 but not α-Syn contributes to hippocampal CA2-specific pyramidal neuronal loss and overall hippocampal atrophy. Further, we report a reduction of hippocampal long-term potentiation and decline in learning and memory performance of wtTDP-43 expressing mice. Elevated wtTDP-43 levels induced selective degeneration of Purkinje cell protein 4 (PCP-4) positive neurons while both wtTDP-43 and α-Syn expression reduced subsets of the glutamate receptor expression in the hippocampus. CONCLUSIONS Overall, our findings suggest the significant vulnerability of hippocampal neurons toward elevated wtTDP-43 levels possibly via PCP-4 and GluR-dependent calcium signaling pathways. Further, we report that wtTDP-43 expression induced selective CA2 subfield degeneration, contributing to the deterioration of the hippocampal-dependent cognitive phenotype.
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Affiliation(s)
- Zainuddin Quadri
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Nicholas Johnson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Frank Zamudio
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Abraian Miller
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Melinda Peters
- Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Shayna Smeltzer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Jerry B Hunt
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Steven B Housley
- Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Breanna Brown
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Susan Kraner
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Kevin Nash
- Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Edwin Weeber
- Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Daniel C Lee
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA
| | - Maj-Linda B Selenica
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA.
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23
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Mosley RL, Lu Y, Olson KE, Machhi J, Yan W, Namminga KL, Smith JR, Shandler SJ, Gendelman HE. A Synthetic Agonist to Vasoactive Intestinal Peptide Receptor-2 Induces Regulatory T Cell Neuroprotective Activities in Models of Parkinson's Disease. Front Cell Neurosci 2019; 13:421. [PMID: 31619964 PMCID: PMC6759633 DOI: 10.3389/fncel.2019.00421] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/02/2019] [Indexed: 12/12/2022] Open
Abstract
A paradigm shift has emerged in Parkinson’s disease (PD) highlighting the prominent role of CD4+ Tregs in pathogenesis and treatment. Bench to bedside research, conducted by others and our own laboratories, advanced a neuroprotective role for Tregs making pharmacologic transformation of immediate need. Herein, a vasoactive intestinal peptide receptor-2 (VIPR2) peptide agonist, LBT-3627, was developed as a neuroprotectant for PD-associated dopaminergic neurodegeneration. Employing both 6-hydroxydopamine (6-OHDA) and α-synuclein (α-Syn) overexpression models in rats, the sequential administration of LBT-3627 increased Treg activity without altering cell numbers both in naïve animals and during progressive nigrostriatal degeneration. LBT-3627 administration was linked to reductions of inflammatory microglia, increased survival of dopaminergic neurons, and improved striatal densities. While α-Syn overexpression resulted in reduced Treg activity, LBT-3627 rescued these functional deficits. This occurred in a dose-dependent manner closely mimicking neuroprotection. Taken together, these data provide the basis for the use of VIPR2 agonists as potent therapeutic immune modulating agents to restore Treg activity, attenuate neuroinflammation, and interdict dopaminergic neurodegeneration in PD. The data underscore an important role of immunity in PD pathogenesis.
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Affiliation(s)
- R Lee Mosley
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Yaman Lu
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Katherine E Olson
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jatin Machhi
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Wenhui Yan
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Krista L Namminga
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jenell R Smith
- Longevity Biotech, Inc., Philadelphia, PA, United States
| | | | - Howard E Gendelman
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, United States
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24
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Bistaffa E, Rossi M, De Luca CMG, Cazzaniga F, Carletta O, Campagnani I, Tagliavini F, Legname G, Giaccone G, Moda F. Prion Efficiently Replicates in α-Synuclein Knockout Mice. Mol Neurobiol 2019; 56:7448-7457. [PMID: 31041657 DOI: 10.1007/s12035-019-1602-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/09/2019] [Indexed: 10/26/2022]
Abstract
Prion diseases are a group of neurodegenerative disorders associated with the conformational conversion of the cellular prion protein (PrPC) into an abnormal misfolded form named PrPSc. Other than accumulating in the brain, PrPSc can bind PrPC and force it to change conformation to PrPSc. The exact mechanism which underlies the process of PrPC/PrPSc conversion still needs to be defined and many molecules or cofactors might be involved. Several studies have documented an important role of PrPC to act as receptor for abnormally folded forms of α-synuclein which are responsible of a group of diseases known as synucleinopathies. The presence of PrPC was required to promote efficient internalization and spreading of abnormal α-synuclein between cells. In this work, we have assessed whether α-synuclein exerts any role in PrPSc conversion and propagation either in vitro or in vivo. Indeed, understanding the mechanism of PrPC/PrPSc conversion and the identification of cofactors involved in this process is crucial for developing new therapeutic strategies. Our results showed that PrPSc was able to efficiently propagate in the brain of animals even in the absence of α-synuclein thus suggesting that this protein did not act as key modulator of prion propagation. Thus, α-synuclein might take part in this process but is not specifically required for sustaining prion conversion and propagation.
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Affiliation(s)
- Edoardo Bistaffa
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Martina Rossi
- Department of Neuroscience, Laboratory of Prion Biology, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Chiara Maria Giulia De Luca
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Neuroscience, Laboratory of Prion Biology, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Federico Cazzaniga
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Olga Carletta
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Ilaria Campagnani
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fabrizio Tagliavini
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Giuseppe Legname
- Department of Neuroscience, Laboratory of Prion Biology, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Giorgio Giaccone
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fabio Moda
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
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25
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Vasili E, Dominguez-Meijide A, Outeiro TF. Spreading of α-Synuclein and Tau: A Systematic Comparison of the Mechanisms Involved. Front Mol Neurosci 2019; 12:107. [PMID: 31105524 PMCID: PMC6494944 DOI: 10.3389/fnmol.2019.00107] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 04/09/2019] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are age-associated neurodegenerative disorders characterized by the misfolding and aggregation of alpha-synuclein (aSyn) and tau, respectively. The coexistence of aSyn and tau aggregates suggests a strong overlap between tauopathies and synucleinopathies. Interestingly, misfolded forms of aSyn and tau can propagate from cell to cell, and throughout the brain, thereby templating the misfolding of native forms of the proteins. The exact mechanisms involved in the propagation of the two proteins show similarities, and are reminiscent of the spreading characteristic of prion diseases. Recently, several models were developed to study the spreading of aSyn and tau. Here, we discuss the mechanisms involved, the similarities and differences between the spreading of the two proteins and that of the prion protein, and the different cell and animal models used for studying these processes. Ultimately, a deeper understanding of the molecular mechanisms involved may lead to the identification of novel targets for therapeutic intervention in a variety of devastating neurodegenerative diseases.
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Affiliation(s)
- Eftychia Vasili
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Goettingen, Goettingen, Germany
| | - Antonio Dominguez-Meijide
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Goettingen, Goettingen, Germany
| | - Tiago Fleming Outeiro
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Goettingen, Goettingen, Germany.,Max Planck Institute for Experimental Medicine, Goettingen, Germany.,The Medical School, Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, United Kingdom
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26
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Williams GP, Schonhoff AM, Jurkuvenaite A, Thome AD, Standaert DG, Harms AS. Targeting of the class II transactivator attenuates inflammation and neurodegeneration in an alpha-synuclein model of Parkinson's disease. J Neuroinflammation 2018; 15:244. [PMID: 30165873 PMCID: PMC6117927 DOI: 10.1186/s12974-018-1286-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/20/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Parkinson's disease (PD) is characterized by intracellular alpha-synuclein (α-syn) inclusions, progressive death of dopaminergic neurons in the substantia nigra pars compacta (SNpc), and activation of the innate and adaptive immune systems. Disruption of immune signaling between the central nervous system (CNS) and periphery, such as through targeting the chemokine receptor type 2 (CCR2) or the major histocompatibility complex II (MHCII), is neuroprotective in rodent models of PD, suggesting a key role for innate and adaptive immunity in disease progression. The purpose of this study was to investigate whether genetic knockout or RNA silencing of the class II transactivator (CIITA), a transcriptional co-activator required for MHCII induction, is effective in reducing the neuroinflammation and neurodegeneration observed in an α-syn mouse model of PD. METHODS In vitro, we utilized microglia cultures from WT or CIITA -/- mice treated with α-syn fibrils to investigate inflammatory iNOS expression and antigen processing via immunocytochemistry (ICC). In vivo, an adeno-associated virus (AAV) was used to overexpress α-syn in WT and CIITA -/- mice as a model for PD. Concurrently with AAV-mediated overexpression of α-syn, WT mice received CIITA-targeted shRNAs packaged in lentiviral constructs. Immunohistochemistry and flow cytometry were used to assess inflammation and peripheral cell infiltration at 4 weeks post transduction, and unbiased stereology was used 6 months post transduction to assess neurodegeneration. RESULTS Using ICC and DQ-ovalbumin, we show that CIITA -/- microglial cultures failed to upregulate iNOS and MHCII expression, and had decreased antigen processing in response to α-syn fibrils when compared to WT microglia. In vivo, global knock-out of CIITA as well as local knockdown using lentiviral shRNAs targeting CIITA attenuated MHCII expression, peripheral immune cell infiltration, and α-syn-induced neurodegeneration. CONCLUSION Our data provide evidence that CIITA is required for α-syn-induced MHCII induction and subsequent infiltration of peripheral immune cells in an α-syn mouse model of PD. Additionally, we demonstrate that CIITA in the CNS drives neuroinflammation and neurodegeneration. These data provide further support that the disruption or modulation of antigen processing and presentation via CIITA is a promising target for therapeutic development in preclinical animal models of PD.
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Affiliation(s)
- Gregory P Williams
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham (UAB), 1719 6th Ave. South, CIRC 525, Birmingham, AL, 35294-0021, USA
| | - Aubrey M Schonhoff
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham (UAB), 1719 6th Ave. South, CIRC 525, Birmingham, AL, 35294-0021, USA
| | - Asta Jurkuvenaite
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham (UAB), 1719 6th Ave. South, CIRC 525, Birmingham, AL, 35294-0021, USA
| | - Aaron D Thome
- Department of Neurology, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - David G Standaert
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham (UAB), 1719 6th Ave. South, CIRC 525, Birmingham, AL, 35294-0021, USA
| | - Ashley S Harms
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham (UAB), 1719 6th Ave. South, CIRC 525, Birmingham, AL, 35294-0021, USA.
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27
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Vo MT, Choi SH, Lee JH, Hong CH, Kim JS, Lee UH, Chung HM, Lee BJ, Park JW, Cho WJ. Tristetraprolin inhibits mitochondrial function through suppression of α-Synuclein expression in cancer cells. Oncotarget 2018; 8:41903-41920. [PMID: 28410208 PMCID: PMC5522037 DOI: 10.18632/oncotarget.16706] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/19/2017] [Indexed: 11/25/2022] Open
Abstract
Mitochondrial dynamics play critical roles in maintaining mitochondrial functions. Here, we report a novel mechanism for regulation of mitochondrial dynamics mediated by tristetraprolin (TTP), an AU-rich element (ARE)-binding protein. Overexpression of TTP resulted in elongated mitochondria, down-regulation of mitochondrial oxidative phosphorylation, reduced membrane potential, cytochrome c release, and increased apoptotic cell death in cancer cells. TTP overexpression inhibited the expression of α-Synuclein (α-Syn). TTP bound to the ARE within the mRNA 3′-untranslated regions (3′-UTRs) of α-Syn and enhanced the decay of α-Syn mRNA. Overexpression of α-Syn without the 3′-UTR restored TTP-induced defects in mitochondrial morphology, mitochondrial oxidative phosphorylation, membrane potential, and apoptotic cell death. Taken together, our data demonstrate that TTP acts as a regulator of mitochondrial dynamics through enhancing degradation of α-Syn mRNA in cancer cells. This finding will increase understanding of the molecular basis of mitochondrial dynamics.
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Affiliation(s)
- Mai-Tram Vo
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Seong Hee Choi
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Ji-Heon Lee
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Gwangjin-Gu, Seoul, 143-701, Korea
| | - Chung Hwan Hong
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Jong Soo Kim
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Gwangjin-Gu, Seoul, 143-701, Korea
| | - Unn Hwa Lee
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Hyung-Min Chung
- Department of Stem Cell Biology, School of Medicine, Konkuk University, Gwangjin-Gu, Seoul, 143-701, Korea
| | - Byung Ju Lee
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Jeong Woo Park
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
| | - Wha Ja Cho
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Korea
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28
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Yan Z, Gibson SA, Buckley JA, Qin H, Benveniste EN. Role of the JAK/STAT signaling pathway in regulation of innate immunity in neuroinflammatory diseases. Clin Immunol 2018; 189:4-13. [PMID: 27713030 PMCID: PMC5573639 DOI: 10.1016/j.clim.2016.09.014] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/20/2016] [Accepted: 09/28/2016] [Indexed: 02/06/2023]
Abstract
The Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signaling pathway is utilized by numerous cytokines and interferons, and is essential for the development and function of both innate and adaptive immunity. Aberrant activation of the JAK/STAT pathway is evident in neuroinflammatory diseases such as Multiple Sclerosis and Parkinson's Disease. Innate immunity is the front line defender of the immune system and is composed of various cell types, including microglia, macrophages and neutrophils. Innate immune responses have both pathogenic and protective roles in neuroinflammation, depending on disease context and the microenvironment in the central nervous system. In this review, we discuss the role of innate immunity in the pathogenesis of neuroinflammatory diseases, how the JAK/STAT signaling pathway regulates the innate immune response, and finally, the potential for ameliorating neuroinflammation by utilization of JAK/STAT inhibitors.
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Affiliation(s)
- Zhaoqi Yan
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Sara A Gibson
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Jessica A Buckley
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Hongwei Qin
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
| | - Etty N Benveniste
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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29
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Cai W, Feng D, Schwarzschild MA, McLean PJ, Chen X. Bimolecular Fluorescence Complementation of Alpha-synuclein Demonstrates its Oligomerization with Dopaminergic Phenotype in Mice. EBioMedicine 2018; 29:13-22. [PMID: 29433982 PMCID: PMC5925445 DOI: 10.1016/j.ebiom.2018.01.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 12/18/2022] Open
Abstract
Alpha-synuclein (αSyn) is encoded by the first causal gene identified in Parkinson's disease (PD) and is the main component of Lewy bodies, a pathological hallmark of PD. aSyn-based animal models have contributed to our understanding of PD pathophysiology and to the development of therapeutics. Overexpression of human wildtype αSyn by viral vectors in rodents recapitulates the loss of dopaminergic neurons from the substantia nigra, another defining pathological feature of the disease. The development of a rat model exhibiting bimolecular fluorescence complementation (BiFC) of αSyn by recombinant adeno-associated virus facilitates detection of the toxic αSyn oligomers species. We report here neurochemical, neuropathological and behavioral characterization of BiFC of αSyn in mice. Overexpression and oligomerization of αSyn through BiFC is detected by conjugated fluorescence. Reduced striatal dopamine and loss of nigral dopaminergic neurons are accompanied neuroinflammation and abnormal motor activities. Our mouse model may provide a valuable tool to study the role of αSyn in PD and to explore therapeutic approaches.
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Affiliation(s)
- Waijiao Cai
- Shanghai Huashan Hospital, Fudan University, Shanghai, China; MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Danielle Feng
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Michael A Schwarzschild
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | | | - Xiqun Chen
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, USA; Shanghai Huashan Hospital, Fudan University, Shanghai, China.
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Steiner JA, Quansah E, Brundin P. The concept of alpha-synuclein as a prion-like protein: ten years after. Cell Tissue Res 2018; 373:161-173. [PMID: 29480459 DOI: 10.1007/s00441-018-2814-1] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/29/2018] [Indexed: 12/18/2022]
Abstract
Parkinson's disease is characterized by the loss of nigrostriatal dopaminergic signaling and the presence of alpha-synuclein aggregates (also called Lewy bodies and neurites) throughout the brain. In 2003, Braak and colleagues created a staging system for Parkinson's disease describing the connection between the alpha-synuclein pathology and disease severity. Later, they suggested that the pathology might initially be triggered by exogenous insults targeting the gut and olfactory system. In 2008, we and other groups documented Lewy pathology in grafted neurons in people with Parkinson's disease who had been transplanted over a decade prior to autopsy. We proposed that the Lewy pathology in the grafted neurons was the result of permissive templating or prion-like spread of alpha-synuclein pathology from neurons in the host to those in the grafts. During the following ten years, several studies described the transmission of alpha-synuclein pathology between neurons, both in cell culture and in experimental animals. Recent research has also begun to identify underlying molecular mechanisms. Collectively, these experimental studies tentatively support the idea that the progression from one Braak stage to the next is the consequence of prion-like propagation of Lewy pathology. However, definitive proof that intercellular propagation of alpha-synuclein pathology occurs in Parkinson's disease cases has proven difficult to secure. In this review, we highlight several open questions that currently prevent us from concluding with certainty that prion-like transfer of alpha-synuclein contributes to the progression of Parkinson's disease.
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Affiliation(s)
- Jennifer A Steiner
- Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave. NE, Grand Rapids, MI, 49503, USA.
| | - Emmanuel Quansah
- Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave. NE, Grand Rapids, MI, 49503, USA
| | - Patrik Brundin
- Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave. NE, Grand Rapids, MI, 49503, USA
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Progranulin Gene Therapy Improves Lysosomal Dysfunction and Microglial Pathology Associated with Frontotemporal Dementia and Neuronal Ceroid Lipofuscinosis. J Neurosci 2018; 38:2341-2358. [PMID: 29378861 DOI: 10.1523/jneurosci.3081-17.2018] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/27/2017] [Accepted: 01/20/2018] [Indexed: 01/18/2023] Open
Abstract
Loss-of-function mutations in progranulin, a lysosomal glycoprotein, cause neurodegenerative disease. Progranulin haploinsufficiency causes frontotemporal dementia (FTD) and complete progranulin deficiency causes CLN11 neuronal ceroid lipofuscinosis (NCL). Progranulin replacement is a rational therapeutic strategy for these disorders, but there are critical unresolved mechanistic questions about a progranulin gene therapy approach, including its potential to reverse existing pathology. Here, we address these issues using an AAV vector (AAV-Grn) to deliver progranulin in Grn-/- mice (both male and female), which model aspects of NCL and FTD pathology, developing lysosomal dysfunction, lipofuscinosis, and microgliosis. We first tested whether AAV-Grn could improve preexisting pathology. Even with treatment after onset of pathology, AAV-Grn reduced lipofuscinosis in several brain regions of Grn-/- mice. AAV-Grn also reduced microgliosis in brain regions distant from the injection site. AAV-expressed progranulin was only detected in neurons, not in microglia, indicating that the microglial activation in progranulin deficiency can be improved by targeting neurons and thus may be driven at least in part by neuronal dysfunction. Even areas with sparse transduction and almost undetectable progranulin showed improvement, indicating that low-level replacement may be sufficiently effective. The beneficial effects of AAV-Grn did not require progranulin binding to sortilin. Finally, we tested whether AAV-Grn improved lysosomal function. AAV-derived progranulin was delivered to the lysosome, ameliorated the accumulation of LAMP-1 in Grn-/- mice, and corrected abnormal cathepsin D activity. These data shed light on progranulin biology and support progranulin-boosting therapies for NCL and FTD due to GRN mutations.SIGNIFICANCE STATEMENT Heterozygous loss-of-function progranulin (GRN) mutations cause frontotemporal dementia (FTD) and homozygous mutations cause neuronal ceroid lipofuscinosis (NCL). Here, we address several mechanistic questions about the potential of progranulin gene therapy for these disorders. GRN mutation carriers with NCL or FTD exhibit lipofuscinosis and Grn-/- mouse models develop a similar pathology. AAV-mediated progranulin delivery reduced lipofuscinosis in Grn-/- mice even after the onset of pathology. AAV delivered progranulin only to neurons, not microglia, but improved microgliosis in several brain regions, indicating cross talk between neuronal and microglial pathology. Its beneficial effects were sortilin independent. AAV-derived progranulin was delivered to lysosomes and corrected lysosomal abnormalities. These data provide in vivo support for the efficacy of progranulin-boosting therapies for FTD and NCL.
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Ganguly U, Chakrabarti SS, Kaur U, Mukherjee A, Chakrabarti S. Alpha-synuclein, Proteotoxicity and Parkinson's Disease: Search for Neuroprotective Therapy. Curr Neuropharmacol 2018; 16:1086-1097. [PMID: 29189163 PMCID: PMC6120113 DOI: 10.2174/1570159x15666171129100944] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 09/11/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND There is a growing body of evidence in animal and cell based models of Parkinson's disease (PD) to suggest that overexpression and / or abnormal accumulation and aggregation of α-synuclein can trigger neuronal death. This important role of α-synuclein in PD pathogenesis is supported by the fact that duplication, triplication and mutations of α-synuclein gene cause familial forms of PD. METHODS A review of literature was performed by searching PubMed and Google Scholar for relevant articles highlighting the pathogenic role of α-synuclein and the potential therapeutic implications of targeting various pathways related to this protein. RESULTS The overexpression and accumulation of α-synuclein within neurons may involve both transcriptional and post-transcriptional mechanisms including a decreased degradation of the protein through proteasomal or autophagic processes. The mechanisms of monomeric α-synuclein aggregating to oligomers and fibrils have been investigated intensively, but it is still not certain which form of this natively unfolded protein is responsible for toxicity. Likewise the proteotoxic pathways induced by α- synuclein leading to neuronal death are not elucidated completely but mitochondrial dysfunction, endoplasmic reticulum (ER) stress and altered ER-golgi transport may play crucial roles in this process. At the molecular level, the ability of α-synuclein to form pores in biomembranes or to interact with specific proteins of the cell organelles and the cytosol could be determining factors in the toxicity of this protein. CONCLUSION Despite many limitations in our present knowledge of physiological and pathological functions of α-synuclein, it appears that this protein may be a target for the development of neuroprotective drugs against PD. This review has discussed many such potential drugs which prevent the expression, accumulation and aggregation of α-synuclein or its interactions with mitochondria or ER and thereby effectively abolish α-synuclein mediated toxicity in different experimental models.
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Affiliation(s)
| | | | | | | | - Sasanka Chakrabarti
- Address correspondence to this author at the Department of Biochemistry, ICARE Institute of Medical Sciences and Research, Haldia, India; Tel: +919874489805; E-mail:
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Harms AS, Thome AD, Yan Z, Schonhoff AM, Williams GP, Li X, Liu Y, Qin H, Benveniste EN, Standaert DG. Peripheral monocyte entry is required for alpha-Synuclein induced inflammation and Neurodegeneration in a model of Parkinson disease. Exp Neurol 2017; 300:179-187. [PMID: 29155051 DOI: 10.1016/j.expneurol.2017.11.010] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/06/2017] [Accepted: 11/15/2017] [Indexed: 12/18/2022]
Abstract
Accumulation of alpha-synuclein (α-syn) in the central nervous system (CNS) is a core feature of Parkinson disease (PD) that leads to activation of the innate immune system, production of inflammatory cytokines and chemokines, and subsequent neurodegeneration. Here, we used heterozygous reporter knock-in mice in which the first exons of the fractalkine receptor (CX3CR1) and of the C-C chemokine receptor type 2 (CCR2) are replaced with fluorescent reporters to study the role of resident microglia (CX3CR1+) and infiltrating peripheral monocytes (CCR2+), respectively, in the CNS. We used an α-syn mouse model induced by viral over-expression of α-syn. We find that in vivo, expression of full-length human α-syn induces robust infiltration of pro-inflammatory CCR2+ peripheral monocytes into the substantia nigra. Genetic deletion of CCR2 prevents α-syn induced monocyte entry, attenuates MHCII expression and blocks the subsequent degeneration of dopaminergic neurons. These results demonstrate that extravasation of pro-inflammatory peripheral monocytes into the CNS plays a key role in neurodegeneration in this model of PD synucleinopathy, and suggest that peripheral monocytes may be a target of neuroprotective therapies for human PD.
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Affiliation(s)
- Ashley S Harms
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Aaron D Thome
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Zhaoqi Yan
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Aubrey M Schonhoff
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Gregory P Williams
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Xinru Li
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Yudong Liu
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hongwei Qin
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Etty N Benveniste
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - David G Standaert
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Arrant AE, Filiano AJ, Unger DE, Young AH, Roberson ED. Restoring neuronal progranulin reverses deficits in a mouse model of frontotemporal dementia. Brain 2017; 140:1447-1465. [PMID: 28379303 DOI: 10.1093/brain/awx060] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/29/2017] [Indexed: 11/14/2022] Open
Abstract
Loss-of-function mutations in progranulin (GRN), a secreted glycoprotein expressed by neurons and microglia, are a common autosomal dominant cause of frontotemporal dementia, a neurodegenerative disease commonly characterized by disrupted social and emotional behaviour. GRN mutations are thought to cause frontotemporal dementia through progranulin haploinsufficiency, therefore, boosting progranulin expression from the intact allele is a rational treatment strategy. However, this approach has not been tested in an animal model of frontotemporal dementia and it is unclear if boosting progranulin could correct pre-existing deficits. Here, we show that adeno-associated virus-driven expression of progranulin in the medial prefrontal cortex reverses social dominance deficits in Grn+/- mice, an animal model of frontotemporal dementia due to GRN mutations. Adeno-associated virus-progranulin also corrected lysosomal abnormalities in Grn+/- mice. The adeno-associated virus-progranulin vector only transduced neurons, suggesting that restoring neuronal progranulin is sufficient to correct deficits in Grn+/- mice. To further test the role of neuronal progranulin in the development of frontotemporal dementia-related deficits, we generated two neuronal progranulin-deficient mouse lines using CaMKII-Cre and Nestin-Cre. Measuring progranulin levels in these lines indicated that most brain progranulin is derived from neurons. Both neuronal progranulin-deficient lines developed social dominance deficits similar to those in global Grn+/- mice, showing that neuronal progranulin deficiency is sufficient to disrupt social behaviour. These data support the concept of progranulin-boosting therapies for frontotemporal dementia and highlight an important role for neuron-derived progranulin in maintaining normal social function.
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Affiliation(s)
- Andrew E Arrant
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anthony J Filiano
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniel E Unger
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Allen H Young
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, and Evelyn F. McKnight Brain Institute, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
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The ER retention protein RER1 promotes alpha-synuclein degradation via the proteasome. PLoS One 2017; 12:e0184262. [PMID: 28877262 PMCID: PMC5587320 DOI: 10.1371/journal.pone.0184262] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/21/2017] [Indexed: 11/19/2022] Open
Abstract
Abnormal accumulation of α-synuclein (αSyn) has been linked to endoplasmic-reticulum (ER) stress, defective intracellular protein/vesicle trafficking, and cytotoxicity. Targeting factors involved in ER-related protein processing and trafficking may, therefore, be a key to modulating αSyn levels and associated toxicity. Recently retention in endoplasmic reticulum 1 (RER1) has been identified as an important ER retrieval/retention factor for Alzheimer's disease proteins and negatively regulates amyloid-β peptide levels. Here, we hypothesized that RER1 might also play an important role in retention/retrieval of αSyn and mediate levels. We expressed RER1 and a C-terminal mutant RER1Δ25, which lacks the ER retention/retrieval function, in HEK293 and H4 neuroglioma cells. RER1 overexpression significantly decreased levels of both wild type and A30P, A53T, and E46K disease causal mutants of αSyn, whereas the RER1Δ25 mutant had a significantly attenuated effect on αSyn. RER1 effects were specific to αSyn and had little to no effect on either βSyn or the Δ71-82 αSyn mutant, which both lack the NAC domain sequence critical for synuclein fibrillization. Tests with proteasomal and macroautophagy inhibitors further demonstrate that RER1 effects on αSyn are primarily mediated through the ubiquitin-proteasome system. RER1 also appears to interact with the ubiquitin ligase NEDD4. RER1 in human diseased brain tissues co-localizes with αSyn-positive Lewy bodies. Together, these findings provide evidence that RER1 is a novel and potential important mediator of elevated αSyn levels. Further investigation of the mechanism of RER1 and downstream effectors on αSyn may yield novel therapeutic targets for modulation in Parkinson disease and related synucleinopathies.
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Fernandes L, Moraes N, Sagrillo FS, Magalhães AV, de Moraes MC, Romão L, Kelly JW, Foguel D, Grimster NP, Palhano FL. An ortho-Iminoquinone Compound Reacts with Lysine Inhibiting Aggregation while Remodeling Mature Amyloid Fibrils. ACS Chem Neurosci 2017; 8:1704-1712. [PMID: 28425704 DOI: 10.1021/acschemneuro.7b00017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Protein aggregation is a hallmark of several neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. It has been shown that lysine residues play a key role in the formation of these aggregates. Thus, the ability to disrupt aggregate formation by covalently modifying lysine residues could lead to the discovery of therapeutically relevant antiamyloidogenesis compounds. Herein, we demonstrate that an ortho-iminoquinone (IQ) can be utilized to inhibit amyloid aggregation. Using alpha-synuclein and Aβ1-40 as model amyloidogenic proteins, we observed that IQ was able to react with lysine residues and reduce amyloid aggregation. We also observed that IQ reacted with free amines within the amyloid fibrils preventing their dissociation and seeding capacity.
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Affiliation(s)
- Luiza Fernandes
- Instituto
de Bioquímica Médica Leopoldo de Meis, Programa de Biologia
Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Nathalia Moraes
- Instituto
de Bioquímica Médica Leopoldo de Meis, Programa de Biologia
Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Fernanda S. Sagrillo
- Department
of Organic Chemistry, Chemistry Institute, Fluminense Federal University, Niteroi, Rio de Janeiro 24020-141, Brazil
| | - Augusto V. Magalhães
- Instituto
de Bioquímica Médica Leopoldo de Meis, Programa de Biologia
Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Marcela C. de Moraes
- Department
of Organic Chemistry, Chemistry Institute, Fluminense Federal University, Niteroi, Rio de Janeiro 24020-141, Brazil
| | - Luciana Romão
- Universidade Federal do Rio de Janeiro, Pólo
de Xerém, Duque de Caxias, Rio de Janeiro 25245-390, Brazil
| | - Jeffery W. Kelly
- Departments
of Chemistry and Molecular Medicine and the Skaggs Institute for Chemical
Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States
| | - Debora Foguel
- Instituto
de Bioquímica Médica Leopoldo de Meis, Programa de Biologia
Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Neil P. Grimster
- Departments
of Chemistry and Molecular Medicine and the Skaggs Institute for Chemical
Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States
| | - Fernando L. Palhano
- Instituto
de Bioquímica Médica Leopoldo de Meis, Programa de Biologia
Estrutural, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
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Nigral injection of a proteasomal inhibitor, lactacystin, induces widespread glial cell activation and shows various phenotypes of Parkinson's disease in young and adult mouse. Exp Brain Res 2017; 235:2189-2202. [PMID: 28439627 DOI: 10.1007/s00221-017-4962-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 04/19/2017] [Indexed: 12/18/2022]
Abstract
Proteinaceous inclusions, called Lewy bodies, are used as a pathological hallmark for Parkinson's disease (PD). Lewy bodies contain insoluble α-synuclein (aSyn) and many other ubiquitinated proteins, suggesting a role for protein degradation system failure in the PD pathogenesis. Indeed, proteasomal dysfunction has been linked to PD but commonly used in vivo toxin models, such as 6-OHDA or MPTP, do not have a significant effect on the proteasomal system or protein aggregation. Therefore, we wanted to study the characteristics of a proteasomal inhibitor, lactacystin, as a PD model on young and adult mice. To study this, we performed stereotactic microinjection of lactacystin above the substantia nigra pars compacta in young (2 month old) and adult (12-14 month old) C57Bl/6 mice. Motor behavior was measured by locomotor activity and cylinder tests, and the markers of neuroinflammation, aSyn, and dopaminergic system were assessed by immunohistochemistry and HPLC. We found that lactacystin induced a Parkinson's disease-like motor phenotype 5-7 days after injection in young and adult mice, and this was associated with widespread neuroinflammation based on glial cell markers, aSyn accumulation in substantia nigra, striatal dopamine decrease, and loss of dopaminergic cell bodies in the substantia nigra and terminals in the striatum. When comparing young and adult mice, adult mice were more sensitive for dopaminergic degeneration after lactacystin injection that further supports the use of adult mice instead of young when modeling neurodegeneration. Our data showed that lactacystin is useful in modeling various aspects of Parkinson's disease, and taken together, our findings emphasize the role of a protein degradation deficit in Parkinson's disease pathology, and support the use of proteasomal inhibitors as Parkinson's disease models.
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Albert K, Voutilainen MH, Domanskyi A, Airavaara M. AAV Vector-Mediated Gene Delivery to Substantia Nigra Dopamine Neurons: Implications for Gene Therapy and Disease Models. Genes (Basel) 2017; 8:genes8020063. [PMID: 28208742 PMCID: PMC5333052 DOI: 10.3390/genes8020063] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 02/03/2017] [Indexed: 12/21/2022] Open
Abstract
Gene delivery using adeno-associated virus (AAV) vectors is a widely used method to transduce neurons in the brain, especially due to its safety, efficacy, and long-lasting expression. In addition, by varying AAV serotype, promotor, and titer, it is possible to affect the cell specificity of expression or the expression levels of the protein of interest. Dopamine neurons in the substantia nigra projecting to the striatum, comprising the nigrostriatal pathway, are involved in movement control and degenerate in Parkinson’s disease. AAV-based gene targeting to the projection area of these neurons in the striatum has been studied extensively to induce the production of neurotrophic factors for disease-modifying therapies for Parkinson’s disease. Much less emphasis has been put on AAV-based gene therapy targeting dopamine neurons in substantia nigra. We will review the literature related to targeting striatum and/or substantia nigra dopamine neurons using AAVs in order to express neuroprotective and neurorestorative molecules, as well as produce animal disease models of Parkinson’s disease. We discuss difficulties in targeting substantia nigra dopamine neurons and their vulnerability to stress in general. Therefore, choosing a proper control for experimental work is not trivial. Since the axons along the nigrostriatal tract are the first to degenerate in Parkinson’s disease, the location to deliver the therapy must be carefully considered. We also review studies using AAV-α-synuclein (α-syn) to target substantia nigra dopamine neurons to produce an α-syn overexpression disease model in rats. Though these studies are able to produce mild dopamine system degeneration in the striatum and substantia nigra and some behavioural effects, there are studies pointing to the toxicity of AAV-carrying green fluorescent protein (GFP), which is often used as a control. Therefore, we discuss the potential difficulties in overexpressing proteins in general in the substantia nigra.
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Affiliation(s)
- Katrina Albert
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland.
| | - Merja H Voutilainen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland.
| | - Andrii Domanskyi
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland.
| | - Mikko Airavaara
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland.
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Ip CW, Klaus LC, Karikari AA, Visanji NP, Brotchie JM, Lang AE, Volkmann J, Koprich JB. AAV1/2-induced overexpression of A53T-α-synuclein in the substantia nigra results in degeneration of the nigrostriatal system with Lewy-like pathology and motor impairment: a new mouse model for Parkinson's disease. Acta Neuropathol Commun 2017; 5:11. [PMID: 28143577 PMCID: PMC5286802 DOI: 10.1186/s40478-017-0416-x] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 01/27/2017] [Indexed: 11/10/2022] Open
Abstract
α-Synuclein is a protein implicated in the etiopathogenesis of Parkinson’s disease (PD). AAV1/2-driven overexpression of human mutated A53T-α-synuclein in rat and monkey substantia nigra (SN) induces degeneration of nigral dopaminergic neurons and decreases striatal dopamine and tyrosine hydroxylase (TH). Given certain advantages of the mouse, especially it being amendable to genetic manipulation, translating the AAV1/2-A53T α-synuclein model to mice would be of significant value. AAV1/2-A53T α-synuclein or AAV1/2 empty vector (EV) at a concentration of 5.16 x 1012 gp/ml were unilaterally injected into the right SN of male adult C57BL/6 mice. Post-mortem examinations included immunohistochemistry to analyze nigral α-synuclein, Ser129 phosphorylated α-synuclein and TH expression, striatal dopamine transporter (DAT) levels by autoradiography and dopamine levels by high performance liquid chromatography. At 10 weeks, in AAV1/2-A53T α-synuclein mice there was a 33% reduction in TH+ dopaminergic nigral neurons (P < 0.001), 29% deficit in striatal DAT binding (P < 0.05), 38% and 33% reductions in dopamine (P < 0.001) and DOPAC (P < 0.01) levels and a 60% increase in dopamine turnover (homovanilic acid/dopamine ratio; P < 0.001). Immunofluorescence showed that the AAV1/2-A53T α-synuclein injected mice had widespread nigral and striatal expression of vector-delivered A53T-α-synuclein. Concurrent staining with human PD SN samples using gold standard histological methodology for Lewy pathology detection by proteinase K digestion and application of specific antibody raised against human Lewy body α-synuclein (LB509) and Ser129 phosphorylated α-synuclein (81A) revealed insoluble α-synuclein aggregates in AAV1/2-A53T α-synuclein mice resembling Lewy-like neurites and bodies. In the cylinder test, we observed significant paw use asymmetry in the AAV1/2-A53T α-synuclein group when compared to EV controls at 5 and 9 weeks post injection (P < 0.001; P < 0.05). These data show that unilateral injection of AAV1/2-A53T α-synuclein into the mouse SN leads to persistent motor deficits, neurodegeneration of the nigrostriatal dopaminergic system and development of Lewy-like pathology, thereby reflecting clinical and pathological hallmarks of human PD.
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Svarcbahs R, Julku UH, Myöhänen TT. Inhibition of Prolyl Oligopeptidase Restores Spontaneous Motor Behavior in the α-Synuclein Virus Vector-Based Parkinson's Disease Mouse Model by Decreasing α-Synuclein Oligomeric Species in Mouse Brain. J Neurosci 2016; 36:12485-12497. [PMID: 27927963 PMCID: PMC6601975 DOI: 10.1523/jneurosci.2309-16.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/19/2016] [Accepted: 10/21/2016] [Indexed: 02/07/2023] Open
Abstract
Decreased clearance of α-synuclein (aSyn) and aSyn protein misfolding and aggregation are seen as major factors in the pathogenesis of Parkinson's disease (PD) and other synucleinopathies that leads to disruption in neuronal function and eventually to cell death. Prolyl oligopeptidase (PREP) can accelerate the aSyn aggregation process, while inhibition of PREP by a small molecule inhibitor decreases aSyn oligomer formation and enhances its clearance via autophagy in different aSyn overexpressing cell types and in transgenic PD animal models. In this study, we investigated the impact of chronic PREP inhibition by a small molecule inhibitor, 4-phenylbutanoyl-l-prolyl-2(S)-cyanopyrrolidine (KYP-2047), on aSyn oligomerization, clearance, and underlying spontaneous motor behavior in a virus vector-based aSyn overexpression mouse model 4 weeks after aSyn microinjections and after the onset of symptomatic forepaw bias. Following 4 weeks of PREP inhibition, we saw an improved spontaneous forelimb use in mice that correlated with a decreased immunoreactivity against oligomer-specific forms of aSyn. Additionally, KYP-2047 had a trend to enhance dopaminergic systems activity. Our results suggest that PREP inhibition exhibits a beneficial effect on the aSyn clearance and aggregation in a virus mediated aSyn overexpression PD mouse model and that PREP inhibitors could be a novel therapeutic strategy for synucleinopathies. SIGNIFICANCE STATEMENT Alpha-synuclein (aSyn) has been implicated in Parkinson's disease, with aSyn aggregates believed to exert toxic effects on neurons, while prolyl oligopeptidase (PREP) has been shown to interact with aSyn both in cells and cell free conditions, thus enhancing its aggregation. We demonstrate the possibility to abolish motor imbalance caused by aSyn viral vector injection with chronic 4 week PREP inhibition by a potent small-molecule PREP inhibitor, 4-phenylbutanoyl-l-prolyl-2(S)-cyanopyrrolidine (KYP-2047). Treatment was initiated postsymptomatically, 4 weeks after aSyn injection. KYP-2047-treated animals had a significantly decreased amount of oligomeric aSyn particles and improved dopamine system activity compared to control animals. To our knowledge, this is the first time viral overexpression of aSyn has been countered and movement impairments abolished after their onset.
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Affiliation(s)
- Reinis Svarcbahs
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, FI-00014 Helsinki, Finland
| | - Ulrika H Julku
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, FI-00014 Helsinki, Finland
| | - Timo T Myöhänen
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, FI-00014 Helsinki, Finland
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Maysinger D, Zhang I. Nutritional and Nanotechnological Modulators of Microglia. Front Immunol 2016; 7:270. [PMID: 27471505 PMCID: PMC4945637 DOI: 10.3389/fimmu.2016.00270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022] Open
Abstract
Microglia are the essential responders to alimentary, pharmacological, and nanotechnological immunomodulators. These neural cells play multiple roles as surveyors, sculptors, and guardians of essential parts of complex neural circuitries. Microglia can play dual roles in the central nervous system; they can be deleterious and/or protective. The immunomodulatory effects of alimentary components, gut microbiota, and nanotechnological products have been investigated in microglia at the single-cell level and in vivo using intravital imaging approaches, and different biochemical assays. This review highlights some of the emerging questions and topics from studies involving alimentation, microbiota, nanotechnological products, and associated problems in this area of research. Some of the advantages and limitations of in vitro and in vivo models used to study the neuromodulatory effects of these factors, as well as the merits and pitfalls of intravital imaging modalities employed are presented.
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Affiliation(s)
- Dusica Maysinger
- Department of Pharmacology and Therapeutics, McGill University , Montreal, QC , Canada
| | - Issan Zhang
- Department of Pharmacology and Therapeutics, McGill University , Montreal, QC , Canada
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microRNA-155 Regulates Alpha-Synuclein-Induced Inflammatory Responses in Models of Parkinson Disease. J Neurosci 2016; 36:2383-90. [PMID: 26911687 DOI: 10.1523/jneurosci.3900-15.2016] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Increasing evidence points to inflammation as a chief mediator of Parkinson's disease (PD), a progressive neurodegenerative disorder characterized by loss of dopamine neurons in the substantia nigra pars compacta (SNpc) and widespread aggregates of the protein α-synuclein (α-syn). Recently, microRNAs, small, noncoding RNAs involved in regulating gene expression at the posttranscriptional level, have been recognized as important regulators of the inflammatory environment. Using an array approach, we found significant upregulation of microRNA-155 (miR-155) in an in vivo model of PD produced by adeno-associated-virus-mediated expression of α-syn. Using a mouse with a complete deletion of miR-155, we found that loss of miR-155 reduced proinflammatory responses to α-syn and blocked α-syn-induced neurodegeneration. In primary microglia from miR-155(-/-) mice, we observed a markedly reduced inflammatory response to α-syn fibrils, with attenuation of major histocompatibility complex class II (MHCII) and proinflammatory inducible nitric oxide synthase expression. Treatment of these microglia with a synthetic mimic of miR-155 restored the inflammatory response to α-syn fibrils. Our results suggest that miR-155 has a central role in the inflammatory response to α-syn in the brain and in α-syn-related neurodegeneration. These effects are at least in part due to a direct role of miR-155 on the microglial response to α-syn. These data implicate miR-155 as a potential therapeutic target for regulating the inflammatory response in PD.
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Volpicelli-Daley LA, Kirik D, Stoyka LE, Standaert DG, Harms AS. How can rAAV-α-synuclein and the fibril α-synuclein models advance our understanding of Parkinson's disease? J Neurochem 2016; 139 Suppl 1:131-155. [PMID: 27018978 DOI: 10.1111/jnc.13627] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 02/29/2016] [Accepted: 03/16/2016] [Indexed: 12/23/2022]
Abstract
Animal models of Parkinson's disease (PD) are important for understanding the mechanisms of the disease and can contribute to developing and validating novel therapeutics. Ideally, these models should replicate the cardinal features of PD, such as progressive neurodegeneration of catecholaminergic neurons and motor defects. Many current PD models emphasize pathological forms of α-synuclein, based on findings that autosomal dominant mutations in α-synuclein and duplications/triplications of the SNCA gene cause PD. In addition, Lewy bodies and Lewy neurites, primarily composed of α-synuclein, represent the predominant pathological characteristics of PD. These inclusions have defined features, such as insolubility in non-ionic detergent, hyperphosphorylation, proteinase K sensitivity, a filamentous appearance by electron microscopy, and β-sheet structure. Furthermore, it has become clear that Lewy bodies and Lewy neurites are found throughout the peripheral and central nervous system, and could account not only for motor symptoms, but also for non-motor symptoms of the disease. The goal of this review is to describe two new α-synuclein-based models: the recombinant adeno-associated viral vector-α-synuclein model and the α-synuclein fibril model. An advantage of both models is that they do not require extensive crossbreeding of rodents transgenic for α-synuclein with other rodents transgenic for genes of interest to study the impact of such genes on PD-related pathology and phenotypes. In addition, abnormal α-synuclein can be expressed in brain regions relevant for disease. Here, we discuss the features of each model, how each model has contributed thus far to our understanding of PD, and the advantages and potential caveats of each model. This review describes two α-synuclein-based rodent models of Parkinson's disease: the rAAV-α-synuclein model and the α-synuclein fibril model. The key features of these models are described, and the extent to which they recapitulate features of PD, such as α-synuclein inclusion formation, loss of dopaminergic synapses in the striatum, motor defects, inflammation, and dopamine neuron death. This article is part of a special issue on Parkinson disease.
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Affiliation(s)
- Laura A Volpicelli-Daley
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama.
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Lindsay E Stoyka
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
| | - David G Standaert
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Ashley S Harms
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
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Benskey MJ, Perez RG, Manfredsson FP. The contribution of alpha synuclein to neuronal survival and function - Implications for Parkinson's disease. J Neurochem 2016; 137:331-59. [PMID: 26852372 PMCID: PMC5021132 DOI: 10.1111/jnc.13570] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 02/06/2023]
Abstract
The aggregation of alpha synuclein (α-syn) is a neuropathological feature that defines a spectrum of disorders collectively termed synucleinopathies, and of these, Parkinson's disease (PD) is arguably the best characterized. Aggregated α-syn is the primary component of Lewy bodies, the defining pathological feature of PD, while mutations or multiplications in the α-syn gene result in familial PD. The high correlation between α-syn burden and PD has led to the hypothesis that α-syn aggregation produces toxicity through a gain-of-function mechanism. However, α-syn has been implicated to function in a diverse range of essential cellular processes such as the regulation of neurotransmission and response to cellular stress. As such, an alternative hypothesis with equal explanatory power is that the aggregation of α-syn results in toxicity because of a toxic loss of necessary α-syn function, following sequestration of functional forms α-syn into insoluble protein aggregates. Within this review, we will provide an overview of the literature linking α-syn to PD and the knowledge gained from current α-syn-based animal models of PD. We will then interpret these data from the viewpoint of the α-syn loss-of-function hypothesis and provide a potential mechanistic model by which loss of α-syn function could result in at least some of the neurodegeneration observed in PD. By providing an alternative perspective on the etiopathogenesis of PD and synucleinopathies, this may reveal alternative avenues of research in order to identify potential novel therapeutic targets for disease modifying strategies. The correlation between α-synuclein burden and Parkinson's disease pathology has led to the hypothesis that α-synuclein aggregation produces toxicity through a gain-of-function mechanism. However, in this review, we discuss data supporting the alternative hypothesis that the aggregation of α-synuclein results in toxicity because of loss of necessary α-synuclein function at the presynaptic terminal, following sequestration of functional forms of α-synuclein into aggregates.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Ruth G Perez
- Department of Biomedical Sciences, Center of Emphasis in Neuroscience, Paul L. Foster School of Medicine, Texas Tech University of the Health Sciences El Paso, El Paso, Texas, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
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Jagmag SA, Tripathi N, Shukla SD, Maiti S, Khurana S. Evaluation of Models of Parkinson's Disease. Front Neurosci 2016; 9:503. [PMID: 26834536 PMCID: PMC4718050 DOI: 10.3389/fnins.2015.00503] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/21/2015] [Indexed: 12/01/2022] Open
Abstract
Parkinson's disease is one of the most common neurodegenerative diseases. Animal models have contributed a large part to our understanding and therapeutics developed for treatment of PD. There are several more exhaustive reviews of literature that provide the initiated insights into the specific models; however a novel synthesis of the basic advantages and disadvantages of different models is much needed. Here we compare both neurotoxin based and genetic models while suggesting some novel avenues in PD modeling. We also highlight the problems faced and promises of all the mammalian models with the hope of providing a framework for comparison of various systems.
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Affiliation(s)
- Shail A Jagmag
- Department of Biology, Indian Institute of Science Education and Research Kolkata, India
| | - Naveen Tripathi
- Department of Biology, Indian Institute of Science Education and Research Kolkata, India
| | - Sunil D Shukla
- Department of Zoology, Government Meera Girl's College Udaipur, India
| | - Sankar Maiti
- Department of Biology, Indian Institute of Science Education and Research Kolkata, India
| | - Sukant Khurana
- Department of Biology, Indian Institute of Science Education and Research Kolkata, India
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Ma S, Fang Z, Luo W, Yang Y, Wang C, Zhang Q, Wang H, Chen H, Chan CB, Liu Z. The C-ETS2-TFEB Axis Promotes Neuron Survival under Oxidative Stress by Regulating Lysosome Activity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:4693703. [PMID: 27195074 PMCID: PMC4853961 DOI: 10.1155/2016/4693703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/05/2016] [Accepted: 02/17/2016] [Indexed: 02/05/2023]
Abstract
Excessive reactive oxygen species/reactive nitrogen species (ROS/RNS) produced as a result of ageing causes damage to macromolecules and organelles or leads to interference of cell signalling pathways, which in turn results in oxidative stress. Oxidative stress occurs in many neurodegenerative diseases (e.g., Parkinson's disease) and contributes to progressive neuronal loss. In this study, we show that cell apoptosis is induced by oxidative stress and that lysosomes play an important role in cell survival under oxidative stress. As a compensatory response to this stress, lysosomal genes were upregulated via induction of transcription factor EB (TFEB). In addition, localization of TFEB to the nucleus was increased by oxidative stress. We also confirmed that TFEB protects cells from oxidative stress both in vitro and in vivo. Finally, we found that C-ETS2 senses oxidative stress, activates TFEB transcription, and mediates the upregulation of lysosomal genes. Our results demonstrate a mechanistic pathway for inducing lysosomal activity during ageing and neurodegeneration.
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Affiliation(s)
- Shumin Ma
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Zijun Fang
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Wenwen Luo
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Yunzhi Yang
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Chenyao Wang
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Qian Zhang
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Huafei Wang
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Huaiyong Chen
- 2Tianjin Haihe Hospital, Tianjin Institute of Respiratory Diseases, Tianjin 300350, China
| | - Chi bun Chan
- 3The University of Oklahoma Health Sciences Center, 940 Stanton L. Young Boulevard, BMSB 634a, Oklahoma City, OK 73104, USA
- 4School of Biological Sciences, The University of Hong Kong, 5N09, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Zhixue Liu
- 1Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
- *Zhixue Liu:
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Single injection of small-molecule amyloid accelerator results in cell death of nigral dopamine neurons in mice. NPJ PARKINSONS DISEASE 2015; 1:15024. [PMID: 28725689 PMCID: PMC5516562 DOI: 10.1038/npjparkd.2015.24] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/14/2015] [Accepted: 11/13/2015] [Indexed: 12/21/2022]
Abstract
The assembly process of α-synuclein toward amyloid fibers is linked to neurodegeneration in Parkinson’s disease. In the present study, we capitalized on the in vitro discovery of a small-molecule accelerator of α-synuclein amyloid formation and assessed its effects when injected in brains of normal mice. An accelerator and an inhibitor of α-synuclein amyloid formation, as well as vehicle only, were injected into the striatum of normal mice and followed by behavioral evaluation, immunohistochemistry, and metabolomics up to six months later. The effects of molecules injected into the substantia nigra of normal and α-synuclein knock-out mice were also analyzed. When accelerator or inhibitor was injected into the brain of normal mice no acute compound toxicity was found. However, 6 months after single striatal injection of accelerator, mice sensorimotor functions were impaired, whereas mice injected with inhibitor had no dysfunctions. Injection of accelerator (but not inhibitor or vehicle) into the substantia nigra revealed significant loss of tyrosine hydroxylase (TH)-positive neurons after 3 months. No loss of TH-positive neurons was found in α-synuclein knock-out mice injected with accelerator into the substantia nigra. Metabolic serum profiles from accelerator-injected normal mice matched those of newly diagnosed Parkinson’s disease patients, whereas the profiles from inhibitor-injected normal mice matched controls. Single inoculation of a small-molecule amyloid accelerator may be a new approach for studies of early events during dopamine neurodegeneration in mice.
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Fractalkine Signaling Regulates the Inflammatory Response in an α-Synuclein Model of Parkinson Disease. PLoS One 2015; 10:e0140566. [PMID: 26469270 PMCID: PMC4607155 DOI: 10.1371/journal.pone.0140566] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Parkinson disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopamine neurons in the substantia nigra pars compacta (SNpc) and widespread aggregates of the protein alpha-synuclein (α-syn). Increasing evidence points to inflammation as a chief mediator; however, the role of α-syn in triggering and sustaining inflammation remains unclear. In models of Alzheimer's disease (AD), multiple sclerosis (MS) and neurotoxin models of PD, the chemokine CX3CL1 (fractalkine) and its receptor (CX3CR1) have important roles in modulating neuroinflammation. METHODS To examine the role of fractalkine signaling in α-syn-induced-neuroinflammation and neurodegeneration, we used an in vivo mouse model in which human α-syn is overexpressed by an adeno associated viral vector serotype 2 (AAV2) and in vitro phagocytosis and protein internalization assays with primary microglia treated with aggregated α-syn. RESULTS We observed that loss of CX3CR1 expression led to a reduced inflammatory response, with reduced IgG deposition and expression of MHCII 4 weeks post-transduction. Six months post transduction, AAV2 mediated overexpression of α-syn leads to loss of dopaminergic neurons, and this loss was not exacerbated in animals with deletion of CX3CR1. To determine the mechanism by which CX3CR1affects inflammatory responses in α-syn-induced inflammation, phagocytosis was assessed using a fluorescent microsphere assay as well as by microglial uptake of aggregated α-syn. CX3CR1-/- microglia showed reduced uptake of fluorescent beads and aggregated α-syn. CONCLUSION Our results suggest that one mechanism by which CX3CR1-/- attenuates inflammation is at the level of phagocytosis of aggregated α-syn by microglia. These data implicate fractalkine signaling as a potential therapeutic target for regulating inflammatory response in α-syn models PD.
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49
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Ding H, Underwood R, Lavalley N, Yacoubian TA. 14-3-3 inhibition promotes dopaminergic neuron loss and 14-3-3θ overexpression promotes recovery in the MPTP mouse model of Parkinson's disease. Neuroscience 2015; 307:73-82. [PMID: 26314634 DOI: 10.1016/j.neuroscience.2015.08.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/25/2015] [Accepted: 08/18/2015] [Indexed: 01/15/2023]
Abstract
14-3-3s are a highly conserved protein family that plays important roles in cell survival and interact with several proteins implicated in Parkinson's disease (PD). Disruption of 14-3-3 expression and function has been implicated in the pathogenesis of PD. We have previously shown that increasing the expression level of 14-3-3θ is protective against rotenone and 1-methyl-4-phenylpyridinium (MPP(+)) in cultured cells. Here, we extend our studies to examine the effects of 14-3-3s in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We first investigated whether targeted nigral 14-3-3θ overexpression mediated by adeno-associated virus offers neuroprotection against MPTP-induced toxicity. 14-3-3θ overexpression using this approach did not reduce MPTP-induced dopaminergic cell loss in the substantia nigra nor the depletion of dopamine (DA) and its metabolites in the striatum at three weeks after MPTP administration. However, 14-3-3θ-overexpressing mice showed a later partial recovery in striatal DA metabolites at eight weeks after MPTP administration compared to controls, suggesting that 14-3-3θ overexpression may help in the functional recovery of those dopaminergic neurons that survive. Conversely, we investigated whether disrupting 14-3-3 function in transgenic mice expressing the pan 14-3-3 inhibitor difopein exacerbates MPTP-induced toxicity. We found that difopein expression promoted dopaminergic cell loss in response to MPTP treatment. Together, these findings suggest that 14-3-3θ overexpression promotes recovery of DA metabolites whereas 14-3-3 inhibition exacerbates neuron loss in the MPTP mouse model of PD.
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Affiliation(s)
- H Ding
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, USA
| | - R Underwood
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, USA
| | - N Lavalley
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, USA
| | - T A Yacoubian
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, USA.
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Alpha-Synuclein affects neurite morphology, autophagy, vesicle transport and axonal degeneration in CNS neurons. Cell Death Dis 2015; 6:e1811. [PMID: 26158517 PMCID: PMC4650722 DOI: 10.1038/cddis.2015.169] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 12/23/2022]
Abstract
Many neuropathological and experimental studies suggest that the degeneration of dopaminergic terminals and axons precedes the demise of dopaminergic neurons in the substantia nigra, which finally results in the clinical symptoms of Parkinson disease (PD). The mechanisms underlying this early axonal degeneration are, however, still poorly understood. Here, we examined the effects of overexpression of human wildtype alpha-synuclein (αSyn-WT), a protein associated with PD, and its mutant variants αSyn-A30P and -A53T on neurite morphology and functional parameters in rat primary midbrain neurons (PMN). Moreover, axonal degeneration after overexpression of αSyn-WT and -A30P was analyzed by live imaging in the rat optic nerve in vivo. We found that overexpression of αSyn-WT and of its mutants A30P and A53T impaired neurite outgrowth of PMN and affected neurite branching assessed by Sholl analysis in a variant-dependent manner. Surprisingly, the number of primary neurites per neuron was increased in neurons transfected with αSyn. Axonal vesicle transport was examined by live imaging of PMN co-transfected with EGFP-labeled synaptophysin. Overexpression of all αSyn variants significantly decreased the number of motile vesicles and decelerated vesicle transport compared with control. Macroautophagic flux in PMN was enhanced by αSyn-WT and -A53T but not by αSyn-A30P. Correspondingly, colocalization of αSyn and the autophagy marker LC3 was reduced for αSyn-A30P compared with the other αSyn variants. The number of mitochondria colocalizing with LC3 as a marker for mitophagy did not differ among the groups. In the rat optic nerve, both αSyn-WT and -A30P accelerated kinetics of acute axonal degeneration following crush lesion as analyzed by in vivo live imaging. We conclude that αSyn overexpression impairs neurite outgrowth and augments axonal degeneration, whereas axonal vesicle transport and autophagy are severely altered.
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