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Lecht S, Lahiani A, Klazas M, Naamneh MS, Rubin L, Dong J, Zheng W, Lazarovici P. Rasagiline Exerts Neuroprotection towards Oxygen-Glucose-Deprivation/Reoxygenation-Induced GAPDH-Mediated Cell Death by Activating Akt/Nrf2 Signaling. Biomedicines 2024; 12:1592. [PMID: 39062165 PMCID: PMC11275171 DOI: 10.3390/biomedicines12071592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/12/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Rasagiline (Azilect®) is a selective monoamine oxidase B (MAO-B) inhibitor that provides symptomatic benefits in Parkinson's disease (PD) treatment and has been found to exert preclinical neuroprotective effects. Here, we investigated the neuroprotective signaling pathways of acute rasagiline treatment for 22 h in PC12 neuronal cultures exposed to oxygen-glucose deprivation (OGD) for 4 h, followed by 18 h of reoxygenation (R), causing 40% aponecrotic cell death. In this study, 3-10 µM rasagiline induced dose-dependent neuroprotection of 20-80%, reduced the production of the neurotoxic reactive oxygen species by 15%, and reduced the nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by 75-90%. In addition, 10 µM rasagiline increased protein kinase B (Akt) phosphorylation by 50% and decreased the protein expression of the ischemia-induced α-synuclein protein by 50% in correlation with the neuroprotective effect. Treatment with 1-5 µM rasagiline induced nuclear shuttling of transcription factor Nrf2 by 40-90% and increased the mRNA levels of the antioxidant enzymes heme oxygenase-1, (NAD (P) H- quinone dehydrogenase, and catalase by 1.8-2.0-fold compared to OGD/R insult. These results indicate that rasagiline provides neuroprotection to the ischemic neuronal cultures through the inhibition of α-synuclein and GAPDH-mediated aponecrotic cell death, as well as via mitochondrial protection, by increasing mitochondria-specific antioxidant enzymes through a mechanism involving the Akt/Nrf2 redox-signaling pathway. These findings may be exploited for neuroprotective drug development in PD and stroke therapy.
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Affiliation(s)
- Shimon Lecht
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Adi Lahiani
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Michal Klazas
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Majdi Saleem Naamneh
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Limor Rubin
- Allergy and Clinical Immunology Unit, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 9112001, Israel
| | - Jiayi Dong
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
| | - Wenhua Zheng
- Center of Reproduction, Development & Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau 999078, China
| | - Philip Lazarovici
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112002, Israel
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Burré J, Edwards RH, Halliday G, Lang AE, Lashuel HA, Melki R, Murayama S, Outeiro TF, Papa SM, Stefanis L, Woerman AL, Surmeier DJ, Kalia LV, Takahashi R. Research Priorities on the Role of α-Synuclein in Parkinson's Disease Pathogenesis. Mov Disord 2024. [PMID: 38946200 DOI: 10.1002/mds.29897] [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: 01/05/2024] [Revised: 05/16/2024] [Accepted: 06/03/2024] [Indexed: 07/02/2024] Open
Abstract
Various forms of Parkinson's disease, including its common sporadic form, are characterized by prominent α-synuclein (αSyn) aggregation in affected brain regions. However, the role of αSyn in the pathogenesis and evolution of the disease remains unclear, despite vast research efforts of more than a quarter century. A better understanding of the role of αSyn, either primary or secondary, is critical for developing disease-modifying therapies. Previous attempts to hone this research have been challenged by experimental limitations, but recent technological advances may facilitate progress. The Scientific Issues Committee of the International Parkinson and Movement Disorder Society (MDS) charged a panel of experts in the field to discuss current scientific priorities and identify research strategies with potential for a breakthrough. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Jacqueline Burré
- Appel Institute for Alzheimer's Disease Research and Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Robert H Edwards
- Department of Physiology and Neurology, University of California, San Francisco School of Medicine, San Francisco, California, USA
| | - Glenda Halliday
- Brain and Mind Centre, School of Medical Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Anthony E Lang
- Edmond J. Safra Program in Parkinson's Disease, Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Hilal A Lashuel
- Laboratory of Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ronald Melki
- Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Shigeo Murayama
- Department of Neuropathology, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
- The Brain Bank for Neurodevelopmental, Neurological and Psychiatric Disorders, United Graduate School of Child Development, Osaka University, Osaka, Japan
| | - Tiago F Outeiro
- Department of Experimental Neurodegeneration, University Medical Center, Göttingen, Germany
- Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Stella M Papa
- Department of Neurology, School of Medicine, and Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
| | - Leonidas Stefanis
- First Department of Neurology, Eginitio Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Amanda L Woerman
- Department of Biology, Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
- Department of Microbiology, Immunology, and Pathology, Prion Research Center, Colorado State University, Fort Collins, Colorado, USA
| | - Dalton James Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland, USA
| | - Lorraine V Kalia
- Edmond J. Safra Program in Parkinson's Disease, Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Soligo M, Manni L, Conti G, Chiaretti A. Intranasal nerve growth factor for prevention and recovery of the outcomes of traumatic brain injury. Neural Regen Res 2023; 18:773-778. [DOI: 10.4103/1673-5374.354513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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4
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Yu HJ, Thijssen E, Brummelen E, Plas JL, Radanovic I, Moerland M, Hsieh E, Groeneveld GJ, Dodart J. A Randomized First‐in‐Human Study With UB‐312, a UBITh® α‐Synuclein Peptide Vaccine. Mov Disord 2022; 37:1416-1424. [PMID: 35426173 PMCID: PMC9545051 DOI: 10.1002/mds.29016] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/04/2022] [Accepted: 03/15/2022] [Indexed: 12/12/2022] Open
Abstract
Background α‐Synuclein (αSyn) is believed to play a central role in Parkinson's disease (PD) neuropathology and is considered a target for disease modification. UB‐312 is a synthetic αSyn peptide conjugated to a T helper peptide and is expected to induce antibodies specifically against oligomeric and fibrillar αSyn, making UB‐312 a potential immunotherapeutic for synucleopathies. Objective To investigate the safety, tolerability, and immunogenicity of UB‐312 vaccination in healthy participants and to determine a safe and immunologically optimal dose for the first‐in‐patient study. Methods Fifty eligible healthy participants were enrolled in a 44‐week, randomized, placebo‐controlled, double‐blind study. Participants in seven cohorts were randomized to three intramuscular UB‐312 or placebo injections at weeks 1, 5, and 13 (doses ranging between 40 and 2000 μg). Safety and tolerability were assessed by adverse events, clinical laboratory, vital signs, electrocardiograms, and neurological and physical examinations. Immunogenicity was assessed by measuring serum and cerebrospinal fluid (CSF) anti‐αSyn antibody concentrations. Results Twenty‐three participants received all three vaccinations of UB‐312. Most adverse events were mild, transient, and self‐resolving. Common treatment‐emergent adverse events included headache, nasopharyngitis, vaccination‐site pain, lumbar puncture‐site pain, and fatigue. UB‐312 induced dose‐ and time‐dependent antibody production. Antibodies were detectable in serum and CSF of all participants receiving the 300/300/300 μg UB‐312 dose regimen. The average CSF/serum ratio was 0.2%. Conclusions UB‐312 was generally safe, well tolerated, and induced anti‐αSyn antibodies in serum and CSF of healthy participants. The 100 and 300 μg doses are selected for further evaluation in participants with PD. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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Affiliation(s)
| | - Eva Thijssen
- Centre for Human Drug Research Leiden the Netherlands
- Leiden University Medical Centre Leiden the Netherlands
| | | | - Johan L. Plas
- Centre for Human Drug Research Leiden the Netherlands
- Leiden University Medical Centre Leiden the Netherlands
| | | | | | | | - Geert Jan Groeneveld
- Centre for Human Drug Research Leiden the Netherlands
- Leiden University Medical Centre Leiden the Netherlands
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5
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Prigent A, Gonzales J, Durand T, Le Berre-Scoul C, Rolli-Derkinderen M, Neunlist M, Derkinderen P. Acute inflammation down-regulates alpha-synuclein expression in enteric neurons. J Neurochem 2019; 148:746-760. [PMID: 30589944 DOI: 10.1111/jnc.14656] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 11/22/2018] [Accepted: 12/21/2018] [Indexed: 12/15/2022]
Abstract
The protein alpha-synuclein whose expression is strongly implicated in Parkinson's disease (PD) is not only expressed in the CNS but also in the enteric nervous system (ENS). The growing body of evidence suggesting that gastrointestinal inflammation is involved in the development of PD led us to investigate the effects of inflammation on alpha-synuclein expression in primary culture of rat ENS and in mice with dextran sulfate sodium-induced colitis. Using western blot and qPCR, we found that both lipopolysaccharide and a combination of tumor necrosis factor-α and interleukin 1-β decreased the expression levels of alpha-synuclein in primary culture of rat ENS, an effect that was prevented in the presence of the p38 inhibitors SB203580 and BIRB 796. Lipopolysaccharide and tumor necrosis factor-α/interleukin 1-β had no effect on alpha-synuclein expression in primary culture of rat CNS and in human erythroid leukemia cells. In mice, acute but not chronic dextran sulfate sodium-induced colitis was associated with a decreased expression of colonic alpha-synuclein. As a whole, our findings indicate that acute inflammatory insults down-regulate alpha-synuclein expression in the ENS via a p38 pathway. They provide new insights into the widely discussed concepts of alpha-synuclein expression and aggregation in the ENS in PD and raise issues about the possible role of gastrointestinal inflammation in the development of PD. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Alice Prigent
- Inserm, U1235, Nantes, France.,University Nantes, Nantes, France
| | - Jacques Gonzales
- Inserm, U1235, Nantes, France.,University Nantes, Nantes, France
| | | | | | | | - Michel Neunlist
- Inserm, U1235, Nantes, France.,University Nantes, Nantes, France
| | - Pascal Derkinderen
- Inserm, U1235, Nantes, France.,University Nantes, Nantes, France.,Department of Neurology, CHU Nantes, Nantes, France
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Aldehyde adducts inhibit 3,4-dihydroxyphenylacetaldehyde-induced α-synuclein aggregation and toxicity: Implication for Parkinson neuroprotective therapy. Eur J Pharmacol 2018; 845:65-73. [PMID: 30579934 DOI: 10.1016/j.ejphar.2018.12.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 12/21/2022]
Abstract
3,4-Dihydroxyphenylacetaldehyde (DOPAL), the monoamine oxidase (MAO) metabolite of dopamine, plays a role in pathogenesis of Parkinson disease, inducing α-synuclein aggregation. DOPAL generates discrete α-synuclein aggregates. Inhibiting this aggregation could provide therapy for slowing Parkinson disease progression. Primary and secondary amines form adducts with aldehydes. Rasagiline and aminoindan contain these amine groups. DOPAL-induced α-synuclein aggregates were resolved in the presence and absence of rasagiline or aminoindan using quantitative Western blotting. DOPAL levels in incubation mixtures, containing increased rasagiline or aminoindan concentrations, were determined by high pressure liquid chromatography (HPLC). Schiff base adducts between DOPAL and rasagiline or aminoindan were determined using mass spectrometry. A neuroprotective effect of rasagiline and aminoindan against DOPAL-induced toxicity was demonstrated using PC-12 cells. Rasagiline and aminoindan significantly reduced aggregation of α-synuclein of all sizes in test tube and PC-12 cells experiments. Dimethylaminoindan did not reduce aggregation. DOPAL levels in incubation mixtures were reduced with increasing rasagiline or aminoindan concentrations but not with dimethylaminoindan. Schiff base adducts between DOPAL and either rasagiline or aminoindan were demonstrated by mass spectrometry. A neuroprotective effect against DOPAL-induced toxicity in PC-12 cells was demonstrated for both rasagiline and aminoindan. Inhibiting DOPAL-induced α-synuclein aggregation through amine adducts provides a therapeutic approach for slowing Parkinson disease progression.
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Goswami P, Joshi N, Singh S. Neurodegenerative signaling factors and mechanisms in Parkinson's pathology. Toxicol In Vitro 2017. [PMID: 28627426 DOI: 10.1016/j.tiv.2017.06.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Parkinson's disease (PD) is a chronic and progressive degenerative disorder of central nervous system which is mainly characterized by selective loss of dopaminergic neurons in the nigrostrial pathway. Clinical symptoms of this devastating disease comprise motor impairments such as resting tremor, bradykinesia, postural instability and rigidity. Current medications only provide symptomatic relief but fail to halt the dopaminergic neuronal death. While the etiology of dopaminergic neuronal death is not fully understood, combination of various molecular mechanisms seems to play a critical role. Studies from experimental animal models have provided crucial insights into the molecular mechanisms in disease pathogenesis and recognized possible targets for therapeutic interventions. Recent findings implicate the involvement of abnormal protein accumulation and phosphorylation, mitochondrial dysfunction, oxidative damage and deregulated kinase signaling as key molecular mechanisms affecting the normal function as well survival of dopaminergic neurons. Here we discuss the relevant findings on the PD pathology related mechanisms and recognition of the cell survival mechanisms which could be used as targets for neuroprotective strategies in preventing this devastating disorder.
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Affiliation(s)
- Poonam Goswami
- Neuronal Cell Death Mechanisms Laboratory, Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India
| | - Neeraj Joshi
- Department of Biochemistry and Biophysics, Helen Diller Comprehensive Cancer Center, University of California San Francisco, USA
| | - Sarika Singh
- Neuronal Cell Death Mechanisms Laboratory, Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India.
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8
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Cartelli D, Cappelletti G. α-Synuclein regulates the partitioning between tubulin dimers and microtubules at neuronal growth cone. Commun Integr Biol 2017. [PMCID: PMC5333521 DOI: 10.1080/19420889.2016.1267076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The partitioning between tubulin dimers and microtubules is fundamental for the regulation of several neuronal activities, from neuronal polarization and processes extension to growth cone remodelling. This phenomenon is modulated by several proteins, including the well-known microtubule destabilizer Stathmin. We recently demonstrated that α-Synuclein, a presynaptic protein associated to Parkinson's disease, shares structural and functional properties with Stathmin, and we showed that α-Synuclein acts as a foldable dynamase. Here, we pinpoint the impact of wild type α-Synuclein on the partitioning between tubulin dimers and microtubules and show that Parkinson's disease-linked mutants lose this capability. Thus, our results indicate a new role for α-Synuclein in regulating microtubule system and support the concept that microtubules and α-Synuclein are partners in the modulation of neuronal health and degenerative processes. Furthermore, these data strengthen our hypothesis of the existence of a functional redundancy between α-Synuclein and Stathmin.
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Affiliation(s)
- Daniele Cartelli
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Graziella Cappelletti
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
- Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milano, Italy
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9
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Abstract
α-Synuclein is a presynaptic protein associated to Parkinson’s disease, which is unstructured when free in the cytoplasm and adopts α helical conformation when bound to vesicles. After decades of intense studies, α-Synuclein physiology is still difficult to clear up due to its interaction with multiple partners and its involvement in a pletora of neuronal functions. Here, we looked at the remarkably neglected interplay between α-Synuclein and microtubules, which potentially impacts on synaptic functionality. In order to identify the mechanisms underlying these actions, we investigated the interaction between purified α-Synuclein and tubulin. We demonstrated that α-Synuclein binds to microtubules and tubulin α2β2 tetramer; the latter interaction inducing the formation of helical segment(s) in the α-Synuclein polypeptide. This structural change seems to enable α-Synuclein to promote microtubule nucleation and to enhance microtubule growth rate and catastrophe frequency, both in vitro and in cell. We also showed that Parkinson’s disease-linked α-Synuclein variants do not undergo tubulin-induced folding and cause tubulin aggregation rather than polymerization. Our data enable us to propose α-Synuclein as a novel, foldable, microtubule-dynamase, which influences microtubule organisation through its binding to tubulin and its regulating effects on microtubule nucleation and dynamics.
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Dermentzaki G, Paschalidis N, Politis PK, Stefanis L. Complex Effects of the ZSCAN21 Transcription Factor on Transcriptional Regulation of α-Synuclein in Primary Neuronal Cultures and in Vivo. J Biol Chem 2016; 291:8756-72. [PMID: 26907683 DOI: 10.1074/jbc.m115.704973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 11/06/2022] Open
Abstract
α-Synuclein, a presynaptic neuronal protein encoded by the SNCA gene, is strongly implicated in Parkinson disease (PD). PD pathogenesis is linked to increased SNCA levels; however, the transcriptional elements that control SNCA expression are still elusive. Previous experiments in PC12 cells demonstrated that the transcription factor zinc finger and SCAN domain containing 21 (ZSCAN21) plays an important regulatory role in SNCA transcription. Currently, we characterized the role of ZSCAN21 in SNCA transcription in primary neuronal cultures and in vivo We found that ZSCAN21 is developmentally expressed in neurons in different rat brain regions. We confirmed its binding in the intron 1 region of SNCA in rat cortical cultures. Lentivirus-mediated silencing of ZSCAN21 increased significantly SNCA promoter activity, mRNA, and protein levels in such cultures. In contrast, ZSCAN21 silencing reduced SNCA in neurosphere cultures. Interestingly, ZSCAN21 overexpression in cortical neurons led to robust mRNA but negligible protein expression, suggesting that ZSCAN21 protein levels are tightly regulated post-transcriptionally and/or post-translationally in primary neurons. Efficient adeno-associated virus-mediated knockdown of ZSCAN21 in the postnatal and adult hippocampus, an area linked with non-motor PD symptoms, revealed no significant alterations in SNCA levels. Overall, our study demonstrates that ZSCAN21 is involved in the transcriptional regulation of SNCA in primary neuronal cultures, but the direction of the effect is variable, likely depending on neuronal maturation. However, the unaltered SNCA levels observed following ZSCAN21 down-regulation in the rat brain, possibly due to compensatory mechanisms, imply that ZSCAN21 is not a master regulator of SNCA in vivo.
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Affiliation(s)
- Georgia Dermentzaki
- From the Biomedical Research Foundation of the Academy of Athens, Athens 11527 and
| | - Nikolaos Paschalidis
- From the Biomedical Research Foundation of the Academy of Athens, Athens 11527 and
| | - Panagiotis K Politis
- From the Biomedical Research Foundation of the Academy of Athens, Athens 11527 and
| | - Leonidas Stefanis
- From the Biomedical Research Foundation of the Academy of Athens, Athens 11527 and the Second Department of Neurology, National and Kapodistrian University of Athens Medical School, Hospital Attikon, Athens 12462, Greece,
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Use of CSF α-synuclein in the differential diagnosis between Alzheimer's disease and other neurodegenerative disorders. Int Psychogeriatr 2015; 27:1429-38. [PMID: 25851548 DOI: 10.1017/s1041610215000447] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The etiology and pathogenesis of neurodegenerative disorders has yet to be elucidated, so their differential diagnosis is a challenge. This is especially true in differentiating Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Parkinson disease (PD), and multiple system atrophy (MSA). METHODS A total of 11 eligible articles were identified by search of electronic databases including PubMed, Springer Link, Elsevier, and the Cochrane Library, up to June 2014. In meta-analyses, standardized mean differences (SMD), with 95% confidence intervals (CI), comparing cerebrospinal fluid (CSF) measures of α-synuclein between the above conditions were calculated using random-effects models. RESULTS CSF α-synuclein concentrations were significantly higher in AD compared to DLB [SMD: 0.32, 95% CI: (0.02, 0.62), z = 2.07, P = 0.038]; PD [SMD: 0.87, 95% CI: (0.15, 1.58), z = 2.38, P = 0.017]; or MSA [SMD: 1.14, 95% CI: (0.15, 2.14), z = 2.25, P = 0.025]. However, no significant difference was found between patients with AD and neurological cognitively normal controls [SMD: 0.02, 95% CI: (-0.21, 0.24), z = 0.13, P = 0.894]. CONCLUSIONS Results of these meta-analysis suggest that quantification of CSF α-synuclein could help distinguish AD from other neurodegenerative disorders such as DLB, PD, or MSA.
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12
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α-Synuclein Misfolding Versus Aggregation Relevance to Parkinson's Disease: Critical Assessment and Modeling. Mol Neurobiol 2014; 51:1417-31. [PMID: 25139280 DOI: 10.1007/s12035-014-8818-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/15/2014] [Indexed: 12/23/2022]
Abstract
α-Synuclein, an abundant and conserved presynaptic brain protein, is implicated as a critical factor in Parkinson's disease (PD). The aggregation of α-synuclein is believed to be a critical event in the disease process. α-Synuclein is characterized by a remarkable conformational plasticity, adopting different conformations depending on the environment. Therefore, it is classified as an "intrinsically disordered protein." Recently, a debate has challenged the view on the intrinsically disordered behavior of α-synuclein in the cell. It has been proposed that α-synuclein is a stable tetramer with a low propensity for aggregation; however, its destabilization leads to protein misfolding and its aggregation kinetics. In our critical analysis, we discussed about major issues: (i) why α-synuclein conformational behavior does not fit into the normal secondary structural characteristics of proteins, (ii) potential amino acids involved in the complexity of misfolding in α-synuclein that leads to aggregation, and (iii) the role of metals in misfolding and aggregation. To evaluate the above critical issues, we developed bioinformatics models related to secondary and tertiary conformations, Ramachandran plot, free energy change, intrinsic disordered prediction, solvent accessibility, and FoldIndex pattern. To the best of our knowledge, this is a novel critical assessment to understand the misfolding biology of synuclein and its relevance to Parkinson's disease.
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13
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Lee KW, Woo JM, Im JY, Park ES, He L, Ichijo H, Junn E, Mouradian MM. Apoptosis signal-regulating kinase 1 modulates the phenotype of α-synuclein transgenic mice. Neurobiol Aging 2014; 36:519-26. [PMID: 25219466 DOI: 10.1016/j.neurobiolaging.2014.07.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 07/12/2014] [Accepted: 07/26/2014] [Indexed: 10/25/2022]
Abstract
α-Synuclein is a key pathogenic protein in α-synucleinopathies including Parkinson's disease, and its overexpression and aggregation in model systems are associated with a neuroinflammatory response and increased oxidative stress. Apoptosis signal-regulating kinase 1 (ASK1) is activated upon stress signaling events such as oxidative stress and is a central player linking oxidative stress with neuroinflammation. Here, we demonstrate that overexpression of human α-synuclein activates ASK1 in both PC12 cells and in the brains of α-synuclein transgenic mice. Deleting ASK1 in mice mitigates the neuronal damage and neuroinflammation induced by α-synuclein and improves performance of the animals on the rotarod. ASK1 deletion does not impact the aggregation profile or phosphorylation state of α-synuclein in the mouse brain. These results collectively implicate ASK1 in the cascade of events triggered by α-synuclein overexpression, likely because of the inflammatory response and oxidative stress that lead to ASK1 activation. These conclusions raise the possibility that potent antioxidants and anti-inflammatory agents may ameliorate the phenotype of α-synucleinopathies.
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Affiliation(s)
- Kang-Woo Lee
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Jong-Min Woo
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Joo-Young Im
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Eun S Park
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Liqiang He
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
| | - Eunsung Junn
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - M Maral Mouradian
- Center for Neurodegenerative and Neuroimmunologic Diseases, Department of Neurology, Rutgers - Robert Wood Johnson Medical School, Piscataway, NJ, USA.
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14
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Scarlata S, Golebiewska U. Linking alpha-synuclein properties with oxidation: a hypothesis on a mechanism underling cellular aggregation. J Bioenerg Biomembr 2014; 46:93-8. [PMID: 24474217 PMCID: PMC4000690 DOI: 10.1007/s10863-014-9540-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
α-Synuclein is a small, natively unstructured protein with propensity to aggregate. α-Synuclein fibrils are major components of Lewy bodies that are hallmarks of many neurodegenerative diseases. The solution properties and aggregation behavior of α-synuclein has been well characterized, but despite numerous studies that address the role of α-synuclein in cells, a clear physiological function of this protein remains a mystery. Over a hundred review articles of α-synuclein have been written in the last decade, making it difficult to list all of the important studies that have added to our insight of α-synuclein physiology. Instead, we briefly review the status of α-synuclein research and propose a model based on the idea that α-synuclein may not have an intrinsic activity in cells but rather, it modifies the function of a group of protein partners that in turn affect cell processes. We propose that it is the loss of its cellular partners under oxidative conditions that promotes α-synuclein aggregation accelerating neuronal death.
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Affiliation(s)
- Suzanne Scarlata
- Department of Physiology & Biophysics, Stony Brook University, Stony Brook, NY, 11794-8661, USA,
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15
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Abstract
Human genetics has indicated a causal role for the protein α-synuclein in the pathogenesis of familial Parkinson's disease (PD), and the aggregation of synuclein in essentially all patients with PD suggests a central role for this protein in the sporadic disorder. Indeed, the accumulation of misfolded α-synuclein now defines multiple forms of neural degeneration. Like many of the proteins that accumulate in other neurodegenerative disorders, however, the normal function of synuclein remains poorly understood. In this article, we review the role of synuclein at the nerve terminal and in membrane remodeling. We also consider the prion-like propagation of misfolded synuclein as a mechanism for the spread of degeneration through the neuraxis.
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Chhangani D, Joshi AP, Mishra A. E3 ubiquitin ligases in protein quality control mechanism. Mol Neurobiol 2012; 45:571-85. [PMID: 22610945 DOI: 10.1007/s12035-012-8273-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 04/26/2012] [Indexed: 12/11/2022]
Abstract
In living cells, polypeptide chains emerging from ribosomes and preexisting polypeptide chains face constant threat of misfolding and aggregation. To prevent protein aggregation and to fulfill their biological activity, generally, protein must fold into its proper three-dimensional structure throughout their lifetimes. Eukaryotic cell possesses a quality control (QC) system to contend the problem of protein misfolding and aggregation. Cells achieve this functional QC system with the help of molecular chaperones and ubiquitin-proteasome system (UPS). The well-conserved UPS regulates the stability of various proteins and maintains all essential cellular function through intracellular protein degradation. E3 ubiquitin ligase enzyme determines specificity for degradation of certain substrates via UPS. New emerging evidences have provided considerable information that various E3 ubiquitin ligases play a major role in cellular QC mechanism and principally designated as QC E3 ubiquitin ligases. Nevertheless, very little is known about how E3 ubiquitin ligase maintains QC mechanism against abnormal proteins under various stress conditions. Here in this review, we highlight and discuss the functions of various E3 ubiquitin ligases implicated in protein QC mechanism. Improving our knowledge about such processes may provide opportunities to modulate protein QC mechanism in age-of-onset diseases that are caused by protein aggregation.
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Affiliation(s)
- Deepak Chhangani
- Biology Laboratory, Indian Institute of Technology Rajasthan, Jodhpur, 342011, India
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17
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Abstract
AbstractGenetic, neuropathological and biochemical evidence implicates α-synuclein, a 140 amino acid presynaptic neuronal protein, in the pathogenesis of Parkinson’s disease and other neurodegenerative disorders. The aggregated protein inclusions mainly containing aberrant α-synuclein are widely accepted as morphological hallmarks of α-synucleinopathies, but their composition and location vary between disorders along with neuronal networks affected. α-Synuclein exists physiologically in both soluble and membran-bound states, in unstructured and α-helical conformations, respectively, while posttranslational modifications due to proteostatic deficits are involved in β-pleated aggregation resulting in formation of typical inclusions. The physiological function of α-synuclein and its role linked to neurodegeneration, however, are incompletely understood. Soluble oligomeric, not fully fibrillar α-synuclein is thought to be neurotoxic, main targets might be the synapse, axons and glia. The effects of aberrant α-synuclein include alterations of calcium homeostasis, mitochondrial dysfunction, oxidative and nitric injuries, cytoskeletal effects, and neuroinflammation. Proteasomal dysfunction might be a common mechanism in the pathogenesis of neuronal degeneration in α-synucleinopathies. However, how α-synuclein induces neurodegeneration remains elusive as its physiological function. Genome wide association studies demonstrated the important role for genetic variants of the SNCA gene encoding α-synuclein in the etiology of Parkinson’s disease, possibly through effects on oxidation, mitochondria, autophagy, and lysosomal function. The neuropathology of synucleinopathies and the role of α-synuclein as a potential biomarker are briefly summarized. Although animal models provided new insights into the pathogenesis of Parkinson disease and multiple system atrophy, most of them do not adequately reproduce the cardinal features of these disorders. Emerging evidence, in addition to synergistic interactions of α-synuclein with various pathogenic proteins, suggests that prionlike induction and seeding of α-synuclein could lead to the spread of the pathology and disease progression. Intervention in the early aggregation pathway, aberrant cellular effects, or secretion of α-synuclein might be targets for neuroprotection and disease-modifying therapy.
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18
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Intrinsically disordered proteins may escape unwanted interactions via functional misfolding. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:693-712. [DOI: 10.1016/j.bbapap.2011.03.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 02/16/2011] [Accepted: 03/16/2011] [Indexed: 12/30/2022]
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Clough RL, Dermentzaki G, Haritou M, Petsakou A, Stefanis L. Regulation of α-synuclein expression in cultured cortical neurons. J Neurochem 2011; 117:275-85. [DOI: 10.1111/j.1471-4159.2011.07199.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Uversky VN. Flexible Nets of Malleable Guardians: Intrinsically Disordered Chaperones in Neurodegenerative Diseases. Chem Rev 2010; 111:1134-66. [DOI: 10.1021/cr100186d] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Vladimir N. Uversky
- Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612, United States, Institute for Intrinsically Disordered Protein Research, Center for Computational Biology and Bioinformatics, University of Indiana School of Medicine, Indianapolis, Indiana 46202, United States, and Institute for Biological Instrumentation, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
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Paillusson S, Tasselli M, Lebouvier T, Mahé MM, Chevalier J, Biraud M, Cario-Toumaniantz C, Neunlist M, Derkinderen P. α-Synuclein expression is induced by depolarization and cyclic AMP in enteric neurons. J Neurochem 2010; 115:694-706. [PMID: 20731759 DOI: 10.1111/j.1471-4159.2010.06962.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Accumulated evidence emphasizes the importance of α-synuclein expression levels in Parkinson's disease (PD) pathogenesis. PD is a multicentric disorder that affects the enteric nervous system (ENS), whose involvement may herald the degenerative process in the CNS. We therefore undertook the present study to investigate the mechanisms involved in the regulation of expression of α-synuclein in the ENS. The regulation of α-synuclein expression was assessed by qPCR and western blot analysis in rat primary culture of ENS treated with KCl and forskolin. A pharmacological approach was used to decipher the signaling pathways involved. Intraperitoneal injections of Bay K-8644 and forskolin were performed in mice, whose proximal colons were further analyzed for α-synuclein expression. Depolarization and forskolin increased α-synuclein mRNA and protein expression in primary cultures of ENS, although L-type calcium channel and protein kinase A, respectively. Both stimuli increased α-synuclein expression through a Ras/extracellular signal-regulated kinases pathway. An increase in α-synuclein expression was also observed in vivo in the ENS of mice injected with Bay K-8644 or forskolin. In conclusion, we have identified stimuli leading to α-synuclein over-expression in the ENS, which could be critical in the initiation of the pathological process in PD.
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Clough RL, Dermentzaki G, Stefanis L. Functional dissection of the alpha-synuclein promoter: transcriptional regulation by ZSCAN21 and ZNF219. J Neurochem 2009; 110:1479-90. [PMID: 19549071 DOI: 10.1111/j.1471-4159.2009.06250.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alpha-synuclein (SNCA) is an abundant neuronal protein involved in synaptic neurotransmission. SNCA expression levels have been strongly implicated in Parkinson's disease pathogenesis. We have previously demonstrated that in the PC12 cell line elements in intron 1 may mediate SNCA transcriptional regulation in response to neurotrophins. We have now identified transcription factor (TF) binding sites in intron 1 and the 5'-promoter of SNCA. A binding site for the TF zinc finger and SCAN domain containing (ZSCAN)21 in the 5'-region of intron 1 is required for intron 1 transcriptional activity. Small interfering RNA against ZSCAN21 inhibits activation in the luciferase assay and diminishes SNCA protein levels in naïve and neurotrophin-treated PC12 cells and in primary cultured cortical neurons, demonstrating that ZSCAN21 is a novel transcriptional regulator of SNCA in neuronal cells. The 5'-promoter of SNCA has a complex architecture, including multiple binding sites for the TF zinc finger protein (ZNF)219, which functions as both an activator and a repressor. Targeting ZSCAN21 or other TFs controlling SNCA transcriptional activity may provide novel therapeutic avenues not only for Parkinson's disease but also for other synucleopathies.
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Affiliation(s)
- Richard Lee Clough
- Division of Basic Neuroscience, Biomedical Research Foundation of the Academy of Athens, Athens 11527, Greece.
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23
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Ohrfelt A, Grognet P, Andreasen N, Wallin A, Vanmechelen E, Blennow K, Zetterberg H. Cerebrospinal fluid alpha-synuclein in neurodegenerative disorders-a marker of synapse loss? Neurosci Lett 2008; 450:332-5. [PMID: 19022350 DOI: 10.1016/j.neulet.2008.11.015] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/04/2008] [Accepted: 11/07/2008] [Indexed: 12/22/2022]
Abstract
The association of alpha-synuclein (alpha-syn) neuropathology with Parkinson's disease (PD) and several related disorders has led to an intense research effort to develop cerebrospinal fluid (CSF)- or blood-based alpha-syn biomarkers for these types of diseases. Recent studies show that alpha-syn is present in CSF and possible to measure using enzyme-linked immunosorbent assay (ELISA). Here, we describe a novel ELISA that allows for quantification of alpha-syn in CSF down to 50pg/mL. The diagnostic value of the test was assessed using CSF samples from 66 Alzheimer's disease (AD) patients, 15PD patients, 15 patients with dementia with Lewy bodies (DLB) and 55 cognitively normal controls. PD and DLB patients and controls displayed similar CSF alpha-syn levels. AD patients had significantly lower alpha-syn levels than controls (median [inter-quartile range] 296 [234-372] and 395 [298-452], respectively, p<0.001). Moreover, AD patients with mini-mental state examination (MMSE) scores below 20 had significantly lower alpha-syn than AD patients with MMSE scores of 20 or higher (p=0.02). There was also a tendency towards a negative correlation between alpha-syn levels and disease duration in the AD group (r=-0.247, p=0.06). Altogether, our results speak against CSF alpha-syn as a reliable biomarker for PD and DLB. The lower alpha-syn levels in AD, as well as the association of alpha-syn reduction with AD severity, approximated by MMSE, suggests that it may be a general marker of synapse loss, a hypothesis that warrants further investigation.
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Affiliation(s)
- Annika Ohrfelt
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Mölndal, Sweden
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24
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Waxman EA, Giasson BI. Molecular mechanisms of alpha-synuclein neurodegeneration. Biochim Biophys Acta Mol Basis Dis 2008; 1792:616-24. [PMID: 18955133 DOI: 10.1016/j.bbadis.2008.09.013] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 09/18/2008] [Accepted: 09/24/2008] [Indexed: 12/31/2022]
Abstract
alpha-Synuclein is an abundant highly charged protein that is normally predominantly localized around synaptic vesicles in presynaptic terminals. Although the function of this protein is still ill-defined, genetic studies have demonstrated that point mutations or genetic alteration (duplications or triplications) that increase the number of copies of the alpha-synuclein (SCNA) gene can cause Parkinson's disease or the related disorder dementia with Lewy bodies. alpha-Synuclein can aberrantly polymerize into fibrils with typical amyloid properties, and these fibrils are the major component of many types of pathological inclusions, including Lewy bodies, which are associated with neurodegenerative diseases, such as Parkinson's disease. Although there is substantial evidence supporting the toxic nature of alpha-synuclein inclusions, other modes of toxicity such as oligomers have been proposed. In this review, some of the evidence for the different mechanisms of alpha-synuclein toxicity is presented and discussed.
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Affiliation(s)
- Elisa A Waxman
- Department of Pharmacology, University of Pennsylvania School of Medicine, 125 John Morgan Building, Philadelphia, PA 19104-6084, USA
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25
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Emmanouilidou E, Stefanis L, Vekrellis K. Cell-produced alpha-synuclein oligomers are targeted to, and impair, the 26S proteasome. Neurobiol Aging 2008; 31:953-68. [PMID: 18715677 DOI: 10.1016/j.neurobiolaging.2008.07.008] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 05/15/2008] [Accepted: 07/11/2008] [Indexed: 12/20/2022]
Abstract
Proteasomal dysfunction may play a role in neurodegenerative conditions and protein aggregation. Overexpression in neuronal cells of alpha-synuclein, a molecule linked to Parkinson's Disease, may lead to proteasomal dysfunction. Using PC12 cells stably expressing wild-type or mutant alpha-synuclein and gel filtration, we demonstrate that soluble, intermediate size oligomers of alpha-synuclein co-elute with the 26S proteasome. These soluble oligomers associate with the 26S proteasome and are significantly increased following treatment with proteasomal, but not lysosomal, inhibitors, indicating specific degradation of these particular species by the 26S proteasome. Importantly, expression of alpha-synuclein resulted in a significant inhibition of all proteasomal activities without affecting the levels or assembly of the 26S proteasome. Pharmacological dissociation of alpha-synuclein oligomers restored proteasomal function and reduced polyubiquitinated protein load in intact cells. Our findings suggest a model where only a subset of specific soluble cell-derived alpha-synuclein oligomers is targeted to the 26S proteasome for degradation, and simultaneously inhibit its function, likely by impeding access of other proteasomal substrates.
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Affiliation(s)
- Evangelia Emmanouilidou
- Division of Basic Neurosciences, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
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26
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Targeting adenoviral transgene expression to neurons. Mol Cell Neurosci 2008; 39:411-7. [PMID: 18722531 DOI: 10.1016/j.mcn.2008.07.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 11/20/2022] Open
Abstract
Adenovirus (Ad) is an efficient and safe vector for CNS gene delivery since it infects non-replicating neurons and does not cause insertional mutagenesis of host cell genomes. However, the promiscuous Ad CAR receptor targets cells non-specifically and activates a host immune response. Using Ad5 containing an expression cassette encoding the gene for green fluorescent protein, gfp, regulated by the neuron specific promoter synapsin-1 and the woodchuck post-transcriptional regulatory element (WPRE), we demonstrate efficient, prolonged and promoter-restricted gfp expression in neurons of mixed primary adult rat dorsal root ganglion (DRG) and retinal cell cultures. We also demonstrate restricted gfp expression in DRG neurons after direct injections of Ad5 containing the synapsin-1(gfp)/WPRE construct into L4 DRG in vivo, while Ad5 CMV(gfp) transfected both DRG glia and neurons. Moreover, since the effective titres of delivered Ad5 are reduced with this neuron specific promoter/WPRE expression cassette, the viral immune challenge should be attenuated when used in vivo.
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27
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Malagelada C, Greene LA. PC12 Cells as a model for parkinson's disease research. PARKINSON'S DISEASE 2008. [DOI: 10.1016/b978-0-12-374028-1.00029-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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28
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Fujita M, Sugama S, Nakai M, Takenouchi T, Wei J, Urano T, Inoue S, Hashimoto M. alpha-Synuclein stimulates differentiation of osteosarcoma cells: relevance to down-regulation of proteasome activity. J Biol Chem 2006; 282:5736-48. [PMID: 17189270 DOI: 10.1074/jbc.m606175200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Because a limited study previously showed that alpha-synuclein (alpha-syn), the major pathogenic protein for Parkinson disease, was expressed in differentiating brain tumors as well as various peripheral cancers, the main objective of the present study was to determine whether alpha-syn might be involved in the regulation of tumor differentiation. For this purpose, alpha-syn and its non-amyloidogenic homologue beta-syn were stably transfected to human osteosarcoma MG63 cell line. Compared with beta-syn-overexpressing and vector-transfected cells, alpha-syn-overexpressing cells exhibited distinct features of differentiated osteoblastic phenotype, as shown by up-regulation of alkaline phosphatase and osteocalcin as well as inductive matrix mineralization. Further studies revealed that proteasome activity was significantly decreased in alpha-syn-overexpressing cells compared with other cell types, consistent with the fact that proteasome inhibitors stimulate differentiation of various osteoblastic cells. In alpha-syn-overexpressing cells, protein kinase C (PKC) activity was significantly decreased, and reactivation of PKC by phorbol ester significantly restored the proteasome activity and abrogated cellular differentiation. Moreover, activity of lysosome was up-regulated in alpha-syn-overexpressing cells, and treatment of these cells with autophagy-lysosomal inhibitors resulted in a decrease of proteasome activity associated with up-regulation of alpha-syn expression, leading to enhance cellular differentiation. Taken together, these results suggest that the stimulatory effect of alpha-syn on tumor differentiation may be attributed to down-regulation of proteasome, which is further modulated by alterations of various factors, such as protein kinase C signaling pathway and a autophagy-lysosomal degradation system. Thus, the mechanism of alpha-syn regulation of tumor differentiation and neuropathological effects of alpha-syn may considerably overlap with each other.
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Affiliation(s)
- Masayo Fujita
- Laboratory for Chemistry and Metabolism, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Tokyo 183-8526, Japan
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29
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Abstract
Alpha-synuclein is an abundant neuronal protein that has been linked to both normal synaptic function and neurodegeneration--in particular, Parkinson's disease (PD). Uncovering mechanisms that control alpha-synuclein transcription is therefore critical for PD pathogenesis and synaptic function. We previously reported that in PC12 cells and primary neurons, alpha-synuclein is transcriptionally up-regulated after application of growth factors. In the current work we have characterized the pathway involved in this regulation in PC12 cells. The MAP/ERK pathway, and in particular Ras, is both sufficient and necessary for the NGF and basic fibroblast growth factor (bFGF) -mediated response. Significantly, response elements for this pathway, including a putative occult promoter, lie within intron 1, a hitherto unappreciated regulatory region of the gene that may be utilized in this or other settings. The PI3 kinase pathway is also involved in alpha-synuclein regulation, but response elements for this pathway appear to lie primarily outside of intron 1. These findings indicate that NGF- and bFGF-mediated signal transduction via the MAP/ERK and PI3 kinase pathways, and in part via regulatory regions within intron 1, may be involved in alpha-synuclein transcriptional regulation. Targeting of these pathways may serve to modulate alpha-synuclein so that it achieves desirable levels within neuronal cells.
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Affiliation(s)
- R Lee Clough
- Division of Basic Neurosciences, Foundation for Biomedical Research of the Academy of Athens (IIBEAA), 11527 Athens, Greece
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Falkenburger BH, Schulz JB. Limitations of cellular models in Parkinson's disease research. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2006:261-8. [PMID: 17017539 DOI: 10.1007/978-3-211-45295-0_40] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cell cultures for Parkinson's disease research have the advantage of virtually unlimited access, they allow rapid screening for disease pathogenesis and drug candidates, and they restrict the necessary number of animal experiments. Limitations of cell cultures, include that the survival of neurons is dependent upon the culture conditions; that the cells do not develop their natural neuronal networks. In most cases, neurons are deprived from the physiological afferent and efferent connections. In Parkinson's disease research, mesencephalic slice cultures, primary immature dopaminergic neurons and immortalized cell lines--either in a proliferating state or in a differentiated state--are used. Neuronal cultures may be plated in the presence or absence of glial cells and serum. These different culture conditions as well as the selection of outcome parameters (morphological evaluation, viability assays, biochemical assays, metabolic assays) have a strong influence on the results of the experiments and the conclusions drawn from them. A primary example is the question of whether L-Dopa is toxic to dopaminergic neurons or whether it provides neurotrophic effects: In pure, neuronal-like cultures, L-Dopa provides toxicity, whereas in the presence of glial cells, it provides trophic effects when applied. The multitude of factors that influence the data generated from cell culture experiments indicates that in order to obtain clear-cut and unambiguous results, investigators need to choose their model carefully and are encouraged to verify their main results with different models.
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Affiliation(s)
- B H Falkenburger
- Department of Neurodegeneration and Restorative Research, Center of Neurology, University of Göttingen, Göttingen, Germany
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31
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Ahn KJ, Paik SR, Chung KC, Kim J. Amino acid sequence motifs and mechanistic features of the membrane translocation of alpha-synuclein. J Neurochem 2006; 97:265-79. [PMID: 16524375 DOI: 10.1111/j.1471-4159.2006.03731.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Many lines of evidence suggest that alpha-synuclein can be secreted from cells and can penetrate into them, although the detailed mechanism is not known. In this study, we investigated the amino acid sequence motifs required for the membrane translocation of alpha-synuclein, and the mechanistic features of the phenomenon. We first showed that not only alpha-synuclein but also beta- and gamma-synucleins penetrated into live cells, indicating that the conserved N-terminal region might be responsible for the membrane translocation. Using a series of deletion mutants, we demonstrated that the 11-amino acid imperfect repeats found in synuclein family members play a critical role in the membrane translocation of these proteins. We further demonstrated that fusion peptides containing the 11-amino acid imperfect repeats of alpha-synuclein can transverse the plasma membrane, and that the membrane translocation efficiency is optimal when the peptide contains two repeat motifs. alpha-Synuclein appeared to be imported rapidly and efficiently into cells, with detectable protein in the cytoplasm within 5 min after exogenous treatment. Interestingly, the import of alpha-synuclein at 4 degrees C was comparable with the import observed at 37 degrees C. Furthermore, membrane translocation of alpha-synuclein was not significantly affected by treatment with inhibitors of endocytosis. These results suggest that the internalization of alpha-synuclein is temperature-insensitive and occurs very rapidly via a mechanism distinct from normal endocytosis.
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Affiliation(s)
- Keun Jae Ahn
- Department of Microbiology and Brain Korea 21 Projects For Medical Science, Yonsei University College of Medicine, Seoul, Korea
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32
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Kowalik-Jankowska T, Rajewska A, Wiśniewska K, Grzonka Z, Jezierska J. Coordination abilities of N-terminal fragments of α-synuclein towards copper(II) ions: A combined potentiometric and spectroscopic study. J Inorg Biochem 2005; 99:2282-91. [PMID: 16203037 DOI: 10.1016/j.jinorgbio.2005.08.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Revised: 08/17/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
Copper(II) complexes of the 1-17 (MDVFMKGLSKAKEGVVA-NH(2)), 1-28 (MDVFMKGLSKAKEGVVAAAEKTKQGVAE-NH(2)), 1-39 (MDVFMKGLSKAKEGVVAAAEKTKQGVAEAPGKTKEGVLY-NH(2)) and 1-39 (A30P) fragments of alpha-synuclein were studied by potentiometric, UV-Vis (UV-visible), CD (circular dichroism) and EPR (electron paramagnetic resonance) spectroscopic methods to determine the stoichiometry, stability constants and coordination modes of the complexes formed. The beta-carboxylate group of Asp residue in second position of the peptide chain coordinates strongly to Cu(II) ion over the pH range 4-9.5 to give unusually stable 2N complex with {NH(2), N(-), beta-COO(-), H(2)O} coordination mode. At pH above 7 the results suggest the formation of 2N, 3N, 4N complexes (in equatorial plane) and the involvement of the lateral NH(2) group of Lys residue in the axial coordination of Cu(II) ion. In CD spectra sigma (epsilon-NH(2)-Lys)-->Cu(II) charge transfer transition is observed. Addition of the 18-28 and 18-39 fragments to the 1-17 peptide does not change the coordination mode and the 1-39 fragment forms the Cu(II) complexes with higher stabilities compared to those of the 1-17, 1-28 and 1-39(A30P) fragments of alpha-synuclein.
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Peng X, Peng XM, Tehranian R, Dietrich P, Stefanis L, Perez RG. α-Synuclein activation of protein phosphatase 2A reduces tyrosine hydroxylase phosphorylation in dopaminergic cells. J Cell Sci 2005; 118:3523-30. [PMID: 16030137 DOI: 10.1242/jcs.02481] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
α-Synuclein is an abundant presynaptic protein implicated in neuronal plasticity and neurodegenerative diseases. Although the function of α-synuclein is not thoroughly elucidated, we found that α-synuclein regulates dopamine synthesis by binding to and inhibiting tyrosine hydroxylase, the rate limiting enzyme in dopamine synthesis. Understanding α-synuclein function in dopaminergic cells should add to our knowledge of this key protein, which is implicated in Parkinson's disease and other disorders. Herein, we report a mechanism by which α-synuclein diminishes tyrosine hydroxylase phosphorylation and activity in stably transfected dopaminergic cells. Short-term regulation of tyrosine hydroxylase depends on the phosphorylation of key seryl residues in the amino-terminal regulatory domain of the protein. Of these, Ser40 contributes significantly to tyrosine hydroxylase activation and dopamine synthesis. We observed that α-synuclein overexpression caused reduced Ser40 phosphorylation in MN9D cells and inducible PC12 cells. Ser40 is phosphorylated chiefly by the cyclic AMP-dependent protein kinase PKA and dephosphorylated almost exclusively by the protein phosphatase, PP2A. Therefore, we measured the impact of α-synuclein overexpression on levels and activity of PKA and PP2A in our cells. PKA was unaffected by α-synuclein. PP2A protein levels also were unchanged, however, the activity of PP2A increased in parallel with α-synuclein expression. Inhibition of PP2A dramatically increased Ser40 phosphorylation only in α-synuclein overexpressors in which α-synuclein was also found to co-immunoprecipitate with PP2A. Together the data reveal a functional interaction between α-synuclein and PP2A that leads to PP2A activation and underscores a key role for α-synuclein in protein phosphorylation.
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Affiliation(s)
- Xiangmin Peng
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Stefanis L, Wang Q, Oo T, Lang-Rollin I, Burke RE, Dauer WT. Lack of alpha-synuclein does not alter apoptosis of neonatal catecholaminergic neurons. Eur J Neurosci 2004; 20:1969-72. [PMID: 15380020 DOI: 10.1111/j.1460-9568.2004.03638.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
alpha-Synuclein is an abundant neuronal protein of uncertain function linked to Parkinson's disease. Numerous studies have proposed an antiapoptotic function for alpha-synuclein, based on overexpression experiments in cell lines. To explore whether alpha-synuclein has such a physiological function, we assessed the response of wild type or alpha-synuclein null neonatal mouse sympathetic neurons to nerve growth factor deprivation, a well-characterized stimulus of neuronal apoptosis. There was no difference in the rate of neuronal loss, neuronal apoptosis, or c-jun phosphorylation. Furthermore, the absence of alpha-synuclein did not alter the magnitude of naturally occurring cell death in vivo in substantia nigra pars compacta. Therefore, alpha-synuclein is unlikely to play a significant role in apoptotic signalling in catecholaminergic neurons of the neonatal nervous system.
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Narayanan V, Guo Y, Scarlata S. Fluorescence Studies Suggest a Role for α-Synuclein in the Phosphatidylinositol Lipid Signaling Pathway. Biochemistry 2004; 44:462-70. [PMID: 15641770 DOI: 10.1021/bi0487140] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alpha-synuclein plays a key role in the pathogenesis of many neurodegenerative diseases. To date, its cellular role has yet to be determined, although it has been proposed to be connected to calcium and G protein-mediated dopamine signaling. Alpha-synuclein is known to bind strongly to model membrane surfaces where it may interact with other membrane-associated proteins. Here, we find that the membrane association of alpha-synuclein is enhanced by the presence of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)] and Ca(2+). We also find that alpha-synuclein interacts with high affinity with the G protein-regulated enzyme phospholipase Cbeta(2) (PLCbeta(2)), which catalyzes the hydrolysis of PI(4,5)P(2). Binding of alpha-synuclein to PLCbeta(2) reduces its catalytic activity by 50%, but causes its level of activation by Gbetagamma subunits to increase from 4- to 24-fold. This effect is greatly reduced for A53T alpha-synuclein, which is a mutant associated with familial Parkinson's disease. PI(4,5)P(2) hydrolysis by PLCbeta(2) results in an increase in the intracellular Ca(2+) concentration, and we find that in cultured cells the presence of alpha-synuclein results in a 6-fold enhancement in the release of Ca(2+) from intracellular stores in response to agents that release Gbetagamma subunits relative to controls. Alpha-synuclein also enhances the increase in the level of inositol phosphates seen upon G protein stimulation, suggesting that it also may interact with PLCbeta(2) in cells. Given that Ca(2+) and dopamine regulation are mediated through PLCbeta and G protein signals, our results suggest that alpha-synuclein may play a role in inositol phospholipid signaling.
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Affiliation(s)
- Vijaya Narayanan
- Department of Physiology and Biophysics, State University of New York, Stony Brook, New York 11794-8661, USA
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36
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Kim S, Jeon BS, Heo C, Im PS, Ahn TB, Seo JH, Kim HS, Park CH, Choi SH, Cho SH, Lee WJ, Suh YH. Alpha-synuclein induces apoptosis by altered expression in human peripheral lymphocyte in Parkinson's disease. FASEB J 2004; 18:1615-7. [PMID: 15289452 DOI: 10.1096/fj.04-1917fje] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Though the etiology of Parkinson's disease (PD) remains unclear, alpha-synuclein (alpha-SN) is regarded as a major causative agent of PD. Several lines of evidence indicate that immunological abnormalities are associated with PD for unknown reasons. The present study was performed to assess whether peripheral blood mononuclear cells (PBMCs) show altered alpha-SN expression in PD patients and to identify its functions, which may be related to peripheral immune abnormalities in PD. alpha-SN was found to be expressed more in 151 idiopathic PD (IPD) patients than in 101 healthy controls, who nevertheless showed as age-dependent increases. By in vitro transfection, alpha-SN expression was shown to be correlated with glucocorticoid sensitive apoptosis, possibly caused by the enhanced expression of glucocorticoid receptor (GR), caspase activations (caspase-8, caspase-9), CD95 up-regulation, and reactive oxygen species (ROS) production. An understanding of the correlation between alpha-SN levels and apoptosis in the presence of the coordinated involvement of multiple processes would provide an insight into the molecular basis of the disease. The present study provides a clue that the alpha-SN may be one of the primary causes of the immune abnormalities observed in PD and offers new targets for pharmacotherapeutic intervention.
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Affiliation(s)
- Seonghan Kim
- Department of Pharmacology, College of Medicine, National Creative Research Initiative Center for Alzheimer's Dementia and Neuroscience Research Institute, MRC, Seoul National University, Republic of Korea
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Smith DH, Uryu K, Saatman KE, Trojanowski JQ, McIntosh TK. Protein accumulation in traumatic brain injury. Neuromolecular Med 2004; 4:59-72. [PMID: 14528053 DOI: 10.1385/nmm:4:1-2:59] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Accepted: 07/14/2003] [Indexed: 12/21/2022]
Abstract
Traumatic brain injury (TBI) is one of the most devastating diseases in our society, accounting for a high percentage of mortality and disability. A major consequence of TBI is the rapid and long-term accumulation of proteins. This process largely reflects the interruption of axonal transport as a result of extensive axonal injury. Although many proteins are found accumulating after TBI, three have received particular attention; beta-amyloid precursor protein and its proteolytic products, amyloid-beta (Abeta) peptides, neurofilament proteins, and synuclein proteins. Massive coaccumulations of all of these proteins are found in damaged axons throughout the white matter after TBI. Additionally, these proteins form aggregates in other neuronal compartments and in brain parenchyma after brain trauma. Interestingly, TBI is also an epigenetic risk factor for developing neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. Here, the similarities and differences of these accumulations with pathologies of neurodegenerative diseases will be explored. In addition, the potential deleterious roles of protein accumulations on functional outcome and progressive neurodegeneration following TBI will be examined.
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Affiliation(s)
- Douglas H Smith
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Brenz Verca MS, Bahi A, Boyer F, Wagner GC, Dreyer JL. Distribution of alpha- and gamma-synucleins in the adult rat brain and their modification by high-dose cocaine treatment. Eur J Neurosci 2003; 18:1923-38. [PMID: 14622225 DOI: 10.1046/j.1460-9568.2003.02913.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Synucleins have attracted much attention because of their involvement in several neurodegenerative disorders. In a screening for genes differentially expressed after high-dose cocaine exposure, we found gamma-synuclein as a major upregulated candidate in the tegmentum. Overexpression of both alpha- and gamma-synuclein after drug treatment was confirmed by means of microarrays, yielding an increase in the hippocampus, the striatum and the tegmentum (2.65 x, 1.96 x and 3.5 x, respectively, for alpha-synuclein vs. 2.7 x, 1.96 x and 7.16 x for gamma-synuclein), but no change in the nucleus accumbens. Investigation of the distribution of mRNA (by in situ hybridization) and of the proteins (by immunocytochemistry) shows in both cases a clearly distinct pattern of expression for alpha- and gamma-synuclein. alpha-synuclein displays a very characteristic distribution, confined to specific nuclei, whereas gamma-synuclein is more widely expressed throughout the brain. mRNA of both alpha- and gamma-synucleins display a complementary pattern of expression all over the cortex. In contrast to gamma-synuclein, alpha-synuclein is neuronal, being only found in NeuN-expressing cells, and is expressed in the basal ganglia (faintly) and in the substantia nigra compacta where it is highly correlated with tyrosine hydroxylase. Immunocytochemistry shows that gamma-synuclein generally colocalizes with glial fibrillary acidic protein-expressing cells and is abundant in the red nucleus, the substantia nigra reticulata and the anterior commissure, while gamma-synuclein mRNA labels the matrix compartments of the caudate-putamen. The role of synucleins in relation to cocaine-induced plasticity or neurotoxicity is discussed.
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Hegde ML, Jagannatha Rao KS. Challenges and complexities of alpha-synuclein toxicity: new postulates in unfolding the mystery associated with Parkinson's disease. Arch Biochem Biophys 2003; 418:169-78. [PMID: 14522588 DOI: 10.1016/j.abb.2003.08.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The discovery of two missense mutations in alpha-synuclein gene and the identification of the alpha-synuclein as the major component of Lewy bodies and Lewy neurites have imparted a new direction in understanding Parkinson's disease. Now that alpha-synuclein has been implicated in several neurodegenerative disorders makes it increasingly clear that aggregation of alpha-synuclein is a hallmark feature in neurodegeneration. Although little has been learned about its normal function, alpha-synuclein appears to be associated with membrane phospholipids and may therefore participate in a number of cell signaling pathways. Here, we review the localization, structure, and function of alpha-synuclein and provide a new hypothesis on, (a) the disruption in the membrane binding ability of synuclein which may be the major culprit leading to the alpha-synuclein aggregation and (b) the complexity associated with nuclear localization of alpha-synuclein and its possible binding property to DNA. Further, we postulated the three possible mechanisms of synuclein induced neuronal degeneration in Parkinson's disease.
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Affiliation(s)
- Muralidhar L Hegde
- Department of Biochemistry and Nutrition, Central Food Technological Research Institute, 570013, Mysore, India
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40
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Martin FL, Williamson SJM, Paleologou KE, Hewitt R, El-Agnaf OMA, Allsop D. Fe(II)-induced DNA damage in alpha-synuclein-transfected human dopaminergic BE(2)-M17 neuroblastoma cells: detection by the Comet assay. J Neurochem 2003; 87:620-30. [PMID: 14535945 DOI: 10.1046/j.1471-4159.2003.02013.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lewy bodies in the brains of patients with Parkinson's disease (PD) contain aggregates of alpha-synuclein (alpha-syn). Missense mutations (A53T or A30P) in the gene encoding alpha-syn are responsible for rare, inherited forms of PD. In this study, we explored the susceptibility of untransfected human dopaminergic BE(2)-M17 neuroblastoma cells, cells transfected with vector only, or cells transfected with wild-type alpha-syn, A30P alpha-syn or A53T alpha-syn to Fe(II)-induced DNA damage in the form of single-strand breaks (SSBs). DNA SSBs were detected following 2-h treatments with various concentrations of Fe(II) (0.01-100.0 microm), using the alkaline single cell-gel electrophoresis ('Comet') assay and quantified by measuring comet tail length (CTL) microm). Fe(II) treatment induced significant increases in CTL in cells transfected with A30P alpha-syn or A53T alpha-syn, even at the lowest concentrations of Fe(II) tested. In comparison, untransfected cells, vector control cells or cells transfected with wild-type alpha-syn exhibited increases in SSBs only when exposed to concentrations of 1.0 microm Fe(II) and above. Even when exposed to higher concentrations (10.0-100.0 microm) of Fe(II), untransfected cells, vector control cells or cells transfected with wild-type alpha-syn were less susceptible to DNA-damage induction than cells transfected with A30P alpha-syn or A53T alpha-syn. Incorporation of DNA-repair inhibitors, hydroxyurea and cytosine arabinoside, enhanced the sensitivity of DNA damage detection. Susceptibility to Fe(II)-induced DNA damage appeared to be dependent on alpha-syn status because cells transfected with wild-type alpha-syn or A53T alpha-syn were equally susceptible to the damaging effects of the mitochondrial respiratory chain inhibitor rotenone. Overall, our data are suggestive of an enhanced susceptibility to the toxic effects of Fe(II) in neuroblastoma cells transfected with mutant alpha-syn associated with inherited forms of PD.
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Affiliation(s)
- Francis L Martin
- Department of Biological Sciences, I.E.N.S., Lancaster University, Lancaster, UK.
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41
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Uryu K, Giasson BI, Longhi L, Martinez D, Murray I, Conte V, Nakamura M, Saatman K, Talbot K, Horiguchi T, McIntosh T, Lee VMY, Trojanowski JQ. Age-dependent synuclein pathology following traumatic brain injury in mice. Exp Neurol 2003; 184:214-24. [PMID: 14637093 DOI: 10.1016/s0014-4886(03)00245-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Synucleins (Syn), a family of synaptic proteins, includes alpha-Syn, which plays a pivotal role in Parkinson's disease and related neurodegenerative diseases (synucleinopathies) by forming distinct brain pathologies (Lewy bodies and neurites). Since traumatic brain injury (TBI) is a poorly understood risk factor for Parkinson's disease, we examined the effects of TBI in the young and aged mouse brain on alpha-, beta-, and gamma-Syn. Immunohistochemical analysis showed that brains from sham-injured young and aged mice had normal alpha- and beta-Syn immunoreactivity (IR) in neuropil of cortex, striatum, and hippocampus with little or no gamma-Syn IR. At 1 week post TBI, the aged mouse brain showed a transient increase of alpha- and beta-Syn IR in the neuropil as well as an induction of gamma-Syn IR in subcortical axons. This was associated with strong labeling of striatal axon bundles by antibodies to altered or nitrated epitopes in alpha-Syn as well as by antibodies to inducible nitric oxide synthase. However, these TBI-induced changes disappeared by 16 weeks post TBI, and altered Syn IR was not seen in young mice subjected to TBI nor in alpha-Syn knockout mice while Western blots confirmed that TBI induced transient alterations of alpha-Syn in the mouse brains. This model of age-dependent TBI-induced transient alterations in alpha-Syn provides an opportunity to examine possible links between TBI and mechanisms of disease in synucleinopathies.
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Affiliation(s)
- K Uryu
- The Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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42
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El-Agnaf OMA, Salem SA, Paleologou KE, Cooper LJ, Fullwood NJ, Gibson MJ, Curran MD, Court JA, Mann DMA, Ikeda SI, Cookson MR, Hardy J, Allsop D. Alpha-synuclein implicated in Parkinson's disease is present in extracellular biological fluids, including human plasma. FASEB J 2003; 17:1945-7. [PMID: 14519670 DOI: 10.1096/fj.03-0098fje] [Citation(s) in RCA: 452] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Parkinson's disease (PD) and other related disorders are characterized by the accumulation of fibrillar aggregates of alpha-synuclein protein (alpha-syn) inside brain cells. It is likely that the formation of alpha-syn aggregates plays a seminal role in the pathogenesis of at least some of these diseases, because two different mutations in the gene encoding alpha-syn have been found in inherited forms of PD. alpha-Syn is mainly expressed by neuronal cells and is generally considered to exist as a cytoplasmic protein. Here, we report the unexpected identification of alpha-syn in conditioned culture media from untransfected and alpha-syn-transfected human neuroblastoma cells, as well as in human cerebrospinal fluid and blood plasma. The method used was immunocapture by using anti-alpha-syn antibodies coupled to magnetic beads, followed by detection on Western blots. In all cases, alpha-syn was identified as a single 15 kDa band, which co-migrated with a recombinant form of the protein and reacted with five different antibodies to alpha-syn. Our findings suggest that cells normally secrete alpha-syn into their surrounding media, both in vitro and in vivo. The detection of extracellular alpha-syn and/or its modified forms in body fluids, particularly in human plasma, offers new opportunities for the development of diagnostic tests for PD and related diseases.
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Affiliation(s)
- Omar M A El-Agnaf
- Department of Biological Sciences, Lancaster University, Lancaster LA1 4YQ, UK.
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43
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Rideout HJ, Dietrich P, Savalle M, Dauer WT, Stefanis L. Regulation of alpha-synuclein by bFGF in cultured ventral midbrain dopaminergic neurons. J Neurochem 2003; 84:803-13. [PMID: 12562524 DOI: 10.1046/j.1471-4159.2003.01574.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Alpha-synuclein is a neuronal protein that is implicated in the control of synaptic vesicle function and in Parkinson's disease (PD). Consequently, alterations of alpha-synuclein levels may play a role in neurotransmission and in PD pathogenesis. However, the factors that regulate alpha-synuclein levels are unknown. Growth factors mediate neurotrophic and plasticity effects in CNS neurons, and may play a role in disease states. Here we examine the regulation of alpha-synuclein levels in primary CNS neurons, with particular emphasis on dopaminergic neurons. E18 rat cortical neurons and dopaminergic neurons of E14 rat ventral midbrain showed an induction of alpha-synuclein protein levels with maturation in culture. Application of basic Fibroblast growth factor (bFGF) promoted alpha-synuclein expression selectively within dopaminergic, and not GABAergic or cortical neurons. This induction was blocked by actinomycin D, but not by inhibition of bFGF-induced glial proliferation. alpha-Synuclein levels were not altered by glial-derived neurotrophic factor (GDNF), or by apoptotic stimuli. We conclude that bFGF promotes alpha-synuclein expression in cultured ventral midbrain dopaminergic neurons through a direct transcriptional effect. These results suggest that distinct growth factors may thus mediate plasticity responses or influence disease states in ventral midbrain dopaminergic neurons.
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Affiliation(s)
- Hardy J Rideout
- Department of Neurology, Columbia University, Black Building Room 326, 650 W. 168th Street, New York, NY 10032, USA.
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44
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Chiba-Falek O, Nussbaum RL. Regulation of -Synuclein Expression: Implications for Parkinson's Disease. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 68:409-15. [PMID: 15338643 DOI: 10.1101/sqb.2003.68.409] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- O Chiba-Falek
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892-4472, USA
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45
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Seo JH, Rah JC, Choi SH, Shin JK, Min K, Kim HS, Park CH, Kim S, Kim EM, Lee SH, Lee S, Suh SW, Suh YH. Alpha-synuclein regulates neuronal survival via Bcl-2 family expression and PI3/Akt kinase pathway. FASEB J 2002; 16:1826-8. [PMID: 12223445 DOI: 10.1096/fj.02-0041fje] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2002] [Accepted: 07/15/2002] [Indexed: 11/11/2022]
Abstract
Alpha-synuclein (alpha-SN) is a ubiquitous protein that is especially abundant in the brain and has been postulated to play a central role in the pathogenesis of Parkinson's disease, Alzheimer's disease, and other neurodegenerative disorders. However, little is known about the neuronal functions of alpha-SN and the molecular and cellular mechanisms underlying neuronal loss. Here, we show that alpha-SN plays dual roles of neuroprotection and neurotoxicity depending on its concentration or level of expression. At nanomolar concentrations, a-SN protected neurons against serum deprivation, oxidative stress, and excitotoxicity through the PI3/Akt signaling pathway, and its protective effect was increased by Bcl-2 overexpression. Conversely, at both low micromolar and overexpressed levels in the cell, alpha-SN resulted in cytotoxicity. This might be related to decreased Bcl-xL expression and increased bax expression, which is subsequently followed by cytochrome c release and caspase activation and also by microglia-mediated inflammatory responses via the NFkappaB and mitogen-activated protein kinase pathways.
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Affiliation(s)
- Ji-Heui Seo
- Department of Pharmacology, National Creative Research Initiative Center for Alzheimer's Dementia and Neuroscience Research Institute, MRC, Seoul National University, Seoul 110-799, South Korea
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Ferri CC, Ghasemlou N, Bisby MA, Kawaja MD. Nerve growth factor alters p75 neurotrophin receptor-induced effects in mouse facial motoneurons following axotomy. Brain Res 2002; 950:180-5. [PMID: 12231242 DOI: 10.1016/s0006-8993(02)03035-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The p75 neurotrophin receptor (p75(NTR)) has been implicated as being detrimental for cell survival in facial motoneurons following injury. Although facial motoneurons do not respond to nerve growth factor (NGF) under normal circumstances, this study shows that NGF can interfere with p75(NTR)-mediated cell survival effects on motoneurons following injury. Twenty-five days following injury, the proportion of surviving axotomized neurons in NGF/p75(+/+) mice, which overexpress NGF, was significantly higher compared to wild-type mice, while NGF/p75(-/-) mice, which overexpress NGF but carry two mutated alleles for p75(NTR), had fewer neurons compared to wild-type and p75(-/-) mice, which carry two mutated alleles for p75(NTR), resulting in a lack of functional expression of this receptor. Sympathetic axons sprouted into the axotomized facial nucleus of both NGF/p75(+/+) and NGF/p75(-/-) following injury, due to transgene expression of NGF in reactive astrocytes. Removal of these sympathetic axons enhanced the number of surviving axotomized neurons in NGF/p75(-/-) mice but not in NGF/p75(+/+) mice. Although motoneurons do not express trkA and should therefore be unresponsive to NGF, our results reveal that NGF can influence p75-mediated motoneuron survival following axotomy.
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Affiliation(s)
- Catharine C Ferri
- Department of Physiology, Queen's University, ON K7L 3N6, Kingston, Canada
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Expression of A53T mutant but not wild-type alpha-synuclein in PC12 cells induces alterations of the ubiquitin-dependent degradation system, loss of dopamine release, and autophagic cell death. J Neurosci 2002. [PMID: 11739566 DOI: 10.1523/jneurosci.21-24-09549.2001] [Citation(s) in RCA: 387] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alpha-synuclein mutations have been identified in certain families with Parkinson's disease (PD), and alpha-synuclein is a major component of Lewy bodies. Other genetic data indicate that the ubiquitin-dependent proteolytic system is involved in PD pathogenesis. We have generated stable PC12 cell lines expressing wild-type or A53T mutant human alpha-synuclein. Lines expressing mutant but not wild-type alpha-synuclein show: (1) disruption of the ubiquitin-dependent proteolytic system, manifested by small cytoplasmic ubiquitinated aggregates and by an increase in polyubiquitinated proteins; (2) enhanced baseline nonapoptotic death; (3) marked accumulation of autophagic-vesicular structures; (4) impairment of lysosomal hydrolysis and proteasomal function; and (5) loss of catecholamine-secreting dense core granules and an absence of depolarization-induced dopamine release. Such findings raise the possibility that the primary abnormality in these cells may involve one or more deficits in the lysosomal and/or proteasomal degradation pathways, which in turn lead to loss of dopaminergic capacity and, ultimately, to death. These cells may serve as a model to study the effects of aberrant alpha-synuclein on dopaminergic cell function and survival.
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48
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Rideout HJ, Larsen KE, Sulzer D, Stefanis L. Proteasomal inhibition leads to formation of ubiquitin/alpha-synuclein-immunoreactive inclusions in PC12 cells. J Neurochem 2001; 78:899-908. [PMID: 11520910 DOI: 10.1046/j.1471-4159.2001.00474.x] [Citation(s) in RCA: 209] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Proteasomal dysfunction has been recently implicated in the pathogenesis of several neurodegenerative diseases, including Parkinson's disease and diffuse Lewy body disease. We have developed an in vitro model of proteasomal dysfunction by applying pharmacological inhibitors of the proteasome, lactacystin or ZIE[O-tBu]-A-leucinal (PSI), to dopaminergic PC12 cells. Proteasomal inhibition caused a dose-dependent increase in death of both naive and neuronally differentiated PC12 cells, which could be prevented by caspase inhibition or CPT-cAMP. A percentage of the surviving cells contained discrete cytoplasmic ubiquitinated inclusions, some of which also contained synuclein-1, the rat homologue of human alpha-synuclein. However the total level of synuclein-1 was not altered by proteasomal inhibition. The ubiquitinated inclusions were present only within surviving cells, and their number was increased if cell death was prevented. We have thus replicated, in this model system, the two cardinal pathological features of Lewy body diseases, neuronal death and the formation of cytoplasmic ubiquitinated inclusions. Our findings suggest that inclusion body formation and cell death may be dissociated from one another.
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Affiliation(s)
- H J Rideout
- Department of Neurology, Columbia University, New York 10032, USA
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