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Cerebrospinal Fluid Alpha-Synuclein Improves the Differentiation between Dementia with Lewy Bodies and Alzheimer's Disease in Clinical Practice. Int J Mol Sci 2022; 23:ijms232113488. [PMID: 36362275 PMCID: PMC9654229 DOI: 10.3390/ijms232113488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
Background: Alpha-synuclein, abnormally aggregated in Dementia with Lewy Bodies (DLB), could represent a potential biomarker to improve the differentiation between DLB and Alzheimer’s disease (AD). Our main objective was to compare Cerebrospinal Fluid (CSF) alpha-synuclein levels between patients with DLB, AD and Neurological Control (NC) individuals. Methods: In a monocentric retrospective study, we assessed CSF alpha-synuclein concentration with a validated ELISA kit (ADx EUROIMMUN) in patients with DLB, AD and NC from a tertiary memory clinic. Between-group comparisons were performed, and Receiver Operating Characteristic analysis was used to identify the best CSF alpha-synuclein threshold. We examined the associations between CSF alpha-synuclein, other core AD CSF biomarkers and brain MRI characteristics. Results: We included 127 participants (mean age: 69.3 ± 8.1, Men: 41.7%). CSF alpha-synuclein levels were significantly lower in DLB than in AD (1.28 ± 0.52 ng/mL vs. 2.26 ± 0.91 ng/mL, respectively, p < 0.001) without differences due to the stage of cognitive impairment. The best alpha-synuclein threshold was characterized by an Area Under the Curve = 0.85, Sensitivity = 82.0% and Specificity = 76.0%. CSF alpha-synuclein was associated with CSF AT(N) biomarkers positivity (p < 0.01) but not with hippocampal atrophy or white matter lesions. Conclusion: CSF Alpha-synuclein evaluation could help to early differentiate patients with DLB and AD in association with existing biomarkers.
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Halliwell B. Reflections of an Aging Free Radical Part 2: Meeting Inspirational People. Antioxid Redox Signal 2022; 38:792-802. [PMID: 35651275 DOI: 10.1089/ars.2022.0070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Significance: During my long career in the field of redox biology, I met many inspiring people, especially Lester Packer. Recent Advances: This special issue of Antioxidants & Redox Signaling is dedicated to Lester Packer. Critical Issues: In this short review, I explore how Lester and other pioneers helped to develop the redox biology field and how I interacted with them. Future Directions: In our research to advance the field of redox biology, we stand on the shoulders of giants, including Lester Packer.
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Affiliation(s)
- Barry Halliwell
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore
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Lin CY, Huang CY, Chen CM, Liu HL. Focused Ultrasound-Induced Blood–Brain Barrier Opening Enhanced α-Synuclein Expression in Mice for Modeling Parkinson’s Disease. Pharmaceutics 2022; 14:pharmaceutics14020444. [PMID: 35214176 PMCID: PMC8876143 DOI: 10.3390/pharmaceutics14020444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/09/2022] [Accepted: 02/15/2022] [Indexed: 12/04/2022] Open
Abstract
Parkinson’s disease (PD) is characterized by α-synuclein (αSNCA) aggregation in dopaminergic neurons. Gradual accumulation of αSNCA aggregates in substantia nigra (SN) diminishes the normal functioning of soluble αSNCA, leading to a loss of dopamine (DA) neurons. In this study, we developed focused ultrasound-targeted microbubble destruction (UTMD)-mediated PD model that could generate the disease phenotype via αSNCA CNS gene delivery. The formation of neuronal aggregates was analyzed with immunostaining. To evaluate the DA cell loss, we used tyrosine hydroxylase immunostaining and HPLC analysis on DA and its two metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). This loss of DA was associated with a dose-dependent impairment in motor function, as assessed by the rotarod motor assessment. We demonstrate that UTMD-induced SNCA expression initiates αSNCA aggregation and results in a 50% loss of DA in SN. UTMD-related dose-dependent neuronal loss was identified, and it correlates with the degree of impairment of motor function. In comparison to chemical neurotoxin 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated and conventional intracerebral (IC)-injected animal models of PD, the UTMD-mediated αSNCA-based mouse model offers the advantage of mimicking the rapid development of the PD phenotype. The PD models that we created using UTMD also prove valuable in assessing specific aspects of PD pathogenesis and can serve as a useful PD model for the development of new therapeutic strategies.
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Affiliation(s)
- Chung-Yin Lin
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University, Taoyuan 33302, Taiwan; (C.-Y.L.); (C.-Y.H.)
- Department of Nephrology and Clinical Position Center, Chang Gung Memorial Hospital, Taoyuan 33302, Taiwan
| | - Ching-Yun Huang
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University, Taoyuan 33302, Taiwan; (C.-Y.L.); (C.-Y.H.)
| | - Chiung-Mei Chen
- Department of Neurology, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Correspondence: (C.-M.C.); (H.-L.L.); Tel.: +886-3-3281200 (ext. 8729) (C.-M.C.); +886-2-33665416 (H.-L.L.)
| | - Hao-Li Liu
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
- Department of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan
- Correspondence: (C.-M.C.); (H.-L.L.); Tel.: +886-3-3281200 (ext. 8729) (C.-M.C.); +886-2-33665416 (H.-L.L.)
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Micheli L, Creanza TM, Ceccarelli M, D'Andrea G, Giacovazzo G, Ancona N, Coccurello R, Scardigli R, Tirone F. Transcriptome Analysis in a Mouse Model of Premature Aging of Dentate Gyrus: Rescue of Alpha-Synuclein Deficit by Virus-Driven Expression or by Running Restores the Defective Neurogenesis. Front Cell Dev Biol 2021; 9:696684. [PMID: 34485283 PMCID: PMC8415876 DOI: 10.3389/fcell.2021.696684] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 07/21/2021] [Indexed: 02/05/2023] Open
Abstract
The dentate gyrus of the hippocampus and the subventricular zone are neurogenic niches where neural stem and progenitor cells replicate throughout life to generate new neurons. The Btg1 gene maintains the stem cells of the neurogenic niches in quiescence. The deletion of Btg1 leads to an early transient increase of stem/progenitor cells division, followed, however, by a decrease during adulthood of their proliferative capability, accompanied by apoptosis. Since a physiological decrease of neurogenesis occurs during aging, the Btg1 knockout mouse may represent a model of neural aging. We have previously observed that the defective neurogenesis of the Btg1 knockout model is rescued by the powerful neurogenic stimulus of physical exercise (running). To identify genes responsible for stem and progenitor cells maintenance, we sought here to find genes underlying this premature neural aging, and whose deregulated expression could be rescued by running. Through RNA sequencing we analyzed the transcriptomic profiles of the dentate gyrus isolated from Btg1 wild-type or Btg1 knockout adult (2-month-old) mice submitted to physical exercise or sedentary. In Btg1 knockout mice, 545 genes were deregulated, relative to wild-type, while 2081 genes were deregulated by running. We identified 42 genes whose expression was not only down-regulated in the dentate gyrus of Btg1 knockout, but was also counter-regulated to control levels by running in Btg1 knockout mice, vs. sedentary. Among these 42 counter-regulated genes, alpha-synuclein (Snca), Fos, Arc and Npas4 showed significantly greater differential regulation. These genes control neural proliferation, apoptosis, plasticity and memory and are involved in aging. In particular, Snca expression decreases during aging. We tested, therefore, whether an Snca-expressing lentivirus, by rescuing the defective Snca levels in the dentate gyrus of Btg1 knockout mice, could also reverse the aging phenotype, in particular the defective neurogenesis. We found that the exogenous expression of Snca reversed the Btg1 knockout-dependent decrease of stem cell proliferation as well as the increase of progenitor cell apoptosis. This indicates that Snca has a functional role in the process of neural aging observed in this model, and also suggests that Snca acts as a positive regulator of stem cell maintenance.
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Affiliation(s)
- Laura Micheli
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
| | - Teresa Maria Creanza
- Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council, Bari, Italy
| | - Manuela Ceccarelli
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
| | - Giorgio D'Andrea
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
| | - Giacomo Giacovazzo
- Preclinical Neuroscience, European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy
| | - Nicola Ancona
- Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, National Research Council, Bari, Italy
| | - Roberto Coccurello
- Preclinical Neuroscience, European Center for Brain Research (CERC)/IRCCS Santa Lucia Foundation, Rome, Italy.,Institute for Complex Systems, National Research Council, Rome, Italy
| | - Raffaella Scardigli
- Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Felice Tirone
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
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Prasad KN, Bondy SC. Can a Micronutrient Mixture Delay the Onset and Progression of Symptoms of Single-Point Mutation Diseases? J Am Coll Nutr 2021; 41:489-498. [PMID: 34227926 DOI: 10.1080/07315724.2021.1910592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Single-point mutation diseases in which substitution of one nucleotide with another in a gene occurs include familial Alzheimer's disease (fAD), familial Parkinson's disease (fPD), and familial Creutzfeldt-Jacob disease (fCJD) as well as Huntington's disease (HD), sickle cell anemia, and hemophilia. Inevitability of occurrence of these diseases is certain. However, the time of appearance of symptoms could be influenced by the diet, environment, and possibly other genetic factors. There are no effective approaches to delay the onset or progression of symptoms of these diseases. The fact that increased oxidative stress and inflammation significantly contribute to the initiation and progression of these point mutation diseases shows that antioxidants could be useful. The major objectives are (a) to present evidence that increased oxidative stress and chronic inflammation are associated with selected single-point mutation diseases, such as fAD, fPD, and fCJD, HD, sickle cell anemia, and hemophilia; (b) to describe limited studies on the role of individual antioxidants in experimental models of some of these diseases; and (c) to discuss a rationale for utilizing a comprehensive mixture of micronutrients, which may delay the development and progression of symptoms of above diseases by simultaneously reducing oxidative and inflammatory damages.Key teaching pointsSelected single-point mutation diseases and their pattern of inheritanceCharacteristics of each selected single-point mutation diseaseEvidence for increased oxidative stress and inflammation in each diseasePotential reasons for failure of single antioxidants in human studiesRationale for using a comprehensive mixture of micronutrients in delaying the onset and progression of single-point mutation diseases.
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Affiliation(s)
| | - Stephen C Bondy
- Department of Occupational and Environmental Medicine and Department of Medicine, University of California Irvine, Irvine, California, USA
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6
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Chang KH, Chen CM. The Role of Oxidative Stress in Parkinson's Disease. Antioxidants (Basel) 2020; 9:antiox9070597. [PMID: 32650609 PMCID: PMC7402083 DOI: 10.3390/antiox9070597] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/24/2022] Open
Abstract
Parkinson’s disease (PD) is caused by progressive neurodegeneration of dopaminergic (DAergic) neurons with abnormal accumulation of α-synuclein in substantia nigra (SN). Studies have suggested the potential involvement of dopamine, iron, calcium, mitochondria and neuroinflammation in contributing to overwhelmed oxidative stress and neurodegeneration in PD. Function studies on PD-causative mutations of SNCA, PRKN, PINK1, DJ-1, LRRK2, FBXO7 and ATP13A2 further indicate the role of oxidative stress in the pathogenesis of PD. Therefore, it is reasonable that molecules involved in oxidative stress, such as DJ-1, coenzyme Q10, uric acid, 8-hydroxy-2’-deoxyguanosin, homocysteine, retinoic acid/carotenes, vitamin E, glutathione peroxidase, superoxide dismutase, xanthine oxidase and products of lipid peroxidation, could be candidate biomarkers for PD. Applications of antioxidants to modulate oxidative stress could be a strategy in treating PD. Although a number of antioxidants, such as creatine, vitamin E, coenzyme Q10, pioglitazone, melatonin and desferrioxamine, have been tested in clinical trials, none of them have demonstrated conclusive evidence to ameliorate the neurodegeneration in PD patients. Difficulties in clinical studies may be caused by the long-standing progression of neurodegeneration, lack of biomarkers for premotor stage of PD and inadequate drug delivery across blood–brain barrier. Solutions for these challenges will be warranted for future studies with novel antioxidative treatment in PD patients.
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Affiliation(s)
| | - Chiung-Mei Chen
- Correspondence: ; Tel.: +886-3-3281200 (ext. 8347); Fax: +886-3-3288849
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7
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Rodríguez-Losada N, de la Rosa J, Larriva M, Wendelbo R, Aguirre JA, Castresana JS, Ballaz SJ. Overexpression of alpha-synuclein promotes both cell proliferation and cell toxicity in human SH-SY5Y neuroblastoma cells. J Adv Res 2020; 23:37-45. [PMID: 32071790 PMCID: PMC7016025 DOI: 10.1016/j.jare.2020.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 01/14/2020] [Accepted: 01/20/2020] [Indexed: 01/05/2023] Open
Abstract
Alpha-Synuclein (aSyn) is a chameleon-like protein. Its overexpression and intracellular deposition defines neurodegenerative α-synucleinopathies including Parkinson's disease. Whether aSyn up-regulation is the cause or the protective reaction to α-synucleinopathies remains unresolved. Remarkably, the accumulation of aSyn is involved in cancer. Here, the neuroblastoma SH-SY5Y cell line was genetically engineered to overexpress aSyn at low and at high levels. aSyn cytotoxicity was assessed by the MTT and vital-dye exclusion methods, observed at the beginning of the sub-culture of low-aSyn overexpressing neurons when cells can barely proliferate exponentially. Conversely, high-aSyn overexpressing cultures grew at high rates while showing enhanced colony formation compared to low-aSyn neurons. Cytotoxicity of aSyn overexpression was indirectly revealed by the addition of pro-oxidant rotenone. Pretreatment with partially reduced graphene oxide, an apoptotic agent, increased toxicity of rotenone in low-aSyn neurons, but, it did not in high-aSyn neurons. Consistent with their enhanced proliferation, high-aSyn neurons showed elevated levels of SMP30, a senescence-marker protein, and the mitosis Ki-67 marker. High-aSyn overexpression conferred to the carcinogenic neurons heightened tumorigenicity and resistance to senescence compared to low-aSyn cells, thus pointing to an inadequate level of aSyn stimulation, rather than the aSyn overload itself, as one of the factors contributing to α-synucleinopathy.
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Affiliation(s)
- Noela Rodríguez-Losada
- Dept. of Human Physiology & Physical Sports Education, Medical School, University of Málaga, Málaga, Spain
| | - Javier de la Rosa
- Dept. of Biochemistry & Genetics, University of Navarra School of Sciences, Pamplona, Spain
| | - María Larriva
- Dept. of Pharmacology & Toxicology, University of Navarra School of Pharmacy and Nutrition, Pamplona, Spain
| | | | - José A. Aguirre
- Dept. of Human Physiology & Physical Sports Education, Medical School, University of Málaga, Málaga, Spain
| | - Javier S. Castresana
- Dept. of Biochemistry & Genetics, University of Navarra School of Sciences, Pamplona, Spain
| | - Santiago J. Ballaz
- School of Biological Sciences & Engineering, Yachay Tech University, Urcuquí, Ecuador
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8
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Pathways of protein synthesis and degradation in PD pathogenesis. PROGRESS IN BRAIN RESEARCH 2020; 252:217-270. [PMID: 32247365 DOI: 10.1016/bs.pbr.2020.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Since the discovery of protein aggregates in the brains of individuals with Parkinson's disease (PD) in the early 20th century, the scientific community has been interested in the role of dysfunctional protein metabolism in PD etiology. Recent advances in the field have implicated defective protein handling underlying PD through genetic, in vitro, and in vivo studies incorporating many disease models alongside neuropathological evidence. Here, we discuss the existing body of research focused on understanding cellular pathways of protein synthesis and degradation, and how aberrations in either system could engender PD pathology with special attention to α-synuclein-related consequences. We consider transcription, translation, and post-translational modification to constitute protein synthesis, and protein degradation to encompass proteasome-, lysosome- and endoplasmic reticulum-dependent mechanisms. Novel findings connecting each of these steps in protein metabolism to development of PD indicate that deregulation of protein production and turnover remains an exciting area in PD research.
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9
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Hyperglycemia aggravates decrease in alpha-synuclein expression in a middle cerebral artery occlusion model. Lab Anim Res 2018; 34:195-202. [PMID: 30671105 PMCID: PMC6333603 DOI: 10.5625/lar.2018.34.4.195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/16/2018] [Accepted: 10/18/2018] [Indexed: 01/04/2023] Open
Abstract
Hyperglycemia is one of the major risk factors for stroke. Hyperglycemia can lead to a more extensive infarct volume, aggravate neuronal damage after cerebral ischemia. α-Synuclein is especially abundant in neuronal tissue, where it underlies the etiopathology of several neurodegenerative diseases. This study investigated whether hyperglycemic conditions regulate the expression of α-synuclein in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury. Male Sprague-Dawley rats were treated with streptozotocin (40 mg/kg) via intraperitoneal injection to induce hyperglycemic conditions. MCAO were performed four weeks after streptozotocin injection to induce focal cerebral ischemia, and cerebral cortex tissues were obtained 24 hours after MCAO. We confirmed that MCAO induced neurological functional deficits and cerebral infarction, and these changes were more extensive in diabetic animals compared to non-diabetic animals. Moreover, we identified a decrease in α-synuclein after MCAO injury. Diabetic animals showed a more serious decrease in α-synuclein than non-diabetic animals. Western blot and reverse-transcription PCR analyses confirmed more extensive decreases in α-synuclein expression in MCAO-injured animals with diabetic condition than these of non-diabetic animals. It is accepted that α-synuclein modulates neuronal cell death and exerts a neuroprotective effect. Thus, the results of this study suggest that hyperglycemic conditions cause more serious brain damage in ischemic brain injuries by decreasing α-synuclein expression.
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Iyer A, Claessens MMAE. Disruptive membrane interactions of alpha-synuclein aggregates. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1867:468-482. [PMID: 30315896 DOI: 10.1016/j.bbapap.2018.10.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/14/2018] [Accepted: 10/04/2018] [Indexed: 12/17/2022]
Abstract
Alpha synuclein (αS) is a ~14 kDa intrinsically disordered protein. Decades of research have increased our knowledge on αS yet its physiological function remains largely elusive. The conversion of monomeric αS into oligomers and amyloid fibrils is believed to play a central role of the pathology of Parkinson's disease (PD). It is becoming increasingly clear that the interactions of αS with cellular membranes are important for both αS's functional and pathogenic actions. Therefore, understanding interactions of αS with membranes seems critical to uncover functional or pathological mechanisms. This review summarizes our current knowledge of how physicochemical properties of phospholipid membranes affect the binding and aggregation of αS species and gives an overview of how post-translational modifications and point mutations in αS affect phospholipid membrane binding and protein aggregation. We discuss the disruptive effects resulting from the interaction of αS aggregate species with membranes and highlight current approaches and hypotheses that seek to understand the pathogenic and/or protective role of αS in PD.
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Affiliation(s)
- Aditya Iyer
- Membrane Enzymology Group, University of Groningen, Groningen 9747 AG, The Netherlands
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Zasso J, Ahmed M, Cutarelli A, Conti L. Inducible Alpha-Synuclein Expression Affects Human Neural Stem Cells' Behavior. Stem Cells Dev 2018; 27:985-994. [PMID: 29669468 DOI: 10.1089/scd.2018.0011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Converging evidence suggest that levels of alpha-synuclein (aSyn) expression play a critical role in Parkinson's disease (PD). Several mutations of the SNCA gene, encoding for aSyn have been associated to either the familial or the sporadic forms of PD. Nonetheless, the mechanism underlying wild-type aSyn-mediated neurotoxicity in neuronal cells as well as its specific driving role in PD pathogenesis has yet to be fully clarified. In this view, the development of proper in vitro cellular systems is a crucial step. In this study, we present a novel human Tet-on human neural stem cell (hNSC) line, in which aSyn timing and level of expression can be tightly experimentally tuned. Induction of aSyn in self-renewing hNSCs leads to progressive formation of aSyn aggregates and impairs their proliferation and cell survival. Furthermore, aSyn induction during the neuronal differentiation process results in reduced neuronal differentiation and increased number of astrocytes and undifferentiated cells in culture. Finally, acute aSyn induction in hNSC-derived dopaminergic neuronal cultures results in cell toxicity. This novel conditional in vitro cell model system may be a valuable tool for dissecting of aSyn pathogenic effects in hNSCs and neurons and in developing new potential therapeutic strategies.
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Affiliation(s)
- Jacopo Zasso
- Centre for Integrative Biology-CIBIO, Università degli Studi di Trento , Trento, Italy
| | - Mastad Ahmed
- Centre for Integrative Biology-CIBIO, Università degli Studi di Trento , Trento, Italy
| | - Alessandro Cutarelli
- Centre for Integrative Biology-CIBIO, Università degli Studi di Trento , Trento, Italy
| | - Luciano Conti
- Centre for Integrative Biology-CIBIO, Università degli Studi di Trento , Trento, Italy
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Chen AYY, Tully T. A stress-enhanced model for discovery of disease-modifying gene: Ece1-suppresses the toxicity of α-synuclein A30P. Neurobiol Dis 2018. [PMID: 29524599 DOI: 10.1016/j.nbd.2018.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease (PD) is a progressive motor neurodegenerative disorder, characterized by a selective loss of dopaminergic neurons in the substantia nigra. The complexity of disease etiology includes both genetic and environmental factors. No effective drug that can modify disease progression and protect dopamine neurons from degeneration is presently available. Human α-Synuclein A30P (A30P) is a mutant gene identified in early onset PD and showed to result selective dopamine neuron loss in transgenic A30P flies and mice. Paraquat (PQ) is an herbicide and an oxidative stress generator, linked to sporadic PD. We hypothesized that vital PD modifier genes are conserved across species and would show unique transcriptional changes to oxidative stress in animals expressing a PD-associated gene, such as A30P. We also hypothesized that manipulation of PD modifier genes would provide neuroprotection across species. To identify disease modifier genes, we performed two independently-duplicated experiments of microarray, capturing genome-wide transcriptional changes in A30P flies, chronically fed with PQ-contaminated food. We hypothesized that the best time point of identifying a disease modifier gene is at time when flies showed maximal combined toxicity of A30P transgene and PQ treatment during an early stage of disease and that effective disease modifiers gene are those showing transcriptional changes to oxidative stress in A30P expressing and not in wild type animals. Fly Neprilysin3 (Nep3) is one identified gene that is highly conserved. Its mouse and human homolog is endothelin-converting enzyme-1 (Ece1). To investigate the neuroprotective effect of Ece1, we used NS1 cells and mouse midbrain neurons expressing A30P, treated with or without PQ. We found that ECE1 expression protected against A30P toxicity on cell viability, on neurite outgrowth and ameliorated A30P accumulation in vitro. Expression of ECE1 in vivo suppressed dopamine neuron loss and alleviated the corresponding motor deficits in mice with A30P-expression. Our study leverages a new approach to identify disease modifier genes using a stress-enhanced PD animal model.
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Affiliation(s)
- Alex Yen-Yu Chen
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA; Graduate Program in Neuroscience, Life Sciences 550, SUNY at Stony Brook, Stony Brook, NY 11794, USA; Dart Neuroscience LLC, 12278 Scripps Summit Dr., San Diego, CA 92131, USA.
| | - Tim Tully
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA; Dart Neuroscience LLC, 12278 Scripps Summit Dr., San Diego, CA 92131, USA.
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Bentea E, Verbruggen L, Massie A. The Proteasome Inhibition Model of Parkinson's Disease. JOURNAL OF PARKINSONS DISEASE 2017; 7:31-63. [PMID: 27802243 PMCID: PMC5302045 DOI: 10.3233/jpd-160921] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The pathological hallmarks of Parkinson's disease are the progressive loss of nigral dopaminergic neurons and the formation of intracellular inclusion bodies, termed Lewy bodies, in surviving neurons. Accumulation of proteins in large insoluble cytoplasmic aggregates has been proposed to result, partly, from a failure in the function of intracellular protein degradation pathways. Evidence in support for such a hypothesis emerged in the beginning of the years 2000 with studies demonstrating structural and functional deficits in the ubiquitin-proteasome pathway in post-mortem nigral tissue of patients with Parkinson's disease. These fundamental findings have inspired the development of a new generation of animal models based on the use of proteasome inhibitors to disturb protein homeostasis and trigger nigral dopaminergic neurodegeneration. In this review, we provide an updated overview of the current approaches in employing proteasome inhibitors to model Parkinson's disease, with particular emphasis on rodent studies. In addition, the mechanisms underlying proteasome inhibition-induced cell death and the validity criteria (construct, face and predictive validity) of the model will be critically discussed. Due to its distinct, but highly relevant mechanism of inducing neuronal death, the proteasome inhibition model represents a useful addition to the repertoire of toxin-based models of Parkinson's disease that might provide novel clues to unravel the complex pathogenesis of this disorder.
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Affiliation(s)
| | | | - Ann Massie
- Correspondence to: Dr. Ann Massie, Department of Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium. Tel.: +32 2 477 4502; E-mail:
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Lieberman OJ, Choi SJ, Kanter E, Saverchenko A, Frier MD, Fiore GM, Wu M, Kondapalli J, Zampese E, Surmeier DJ, Sulzer D, Mosharov EV. α-Synuclein-Dependent Calcium Entry Underlies Differential Sensitivity of Cultured SN and VTA Dopaminergic Neurons to a Parkinsonian Neurotoxin. eNeuro 2017; 4:ENEURO.0167-17.2017. [PMID: 29177188 PMCID: PMC5701296 DOI: 10.1523/eneuro.0167-17.2017] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 11/01/2017] [Accepted: 11/09/2017] [Indexed: 12/27/2022] Open
Abstract
Parkinson's disease (PD) is a debilitating neurodegenerative disease characterized by a loss of dopaminergic neurons in the substantia nigra (SN). Although mitochondrial dysfunction and dysregulated α-synuclein (aSyn) expression are postulated to play a role in PD pathogenesis, it is still debated why neurons of the SN are targeted while neighboring dopaminergic neurons of the ventral tegmental area (VTA) are spared. Using electrochemical and imaging approaches, we investigated metabolic changes in cultured primary mouse midbrain dopaminergic neurons exposed to a parkinsonian neurotoxin, 1-methyl-4-phenylpyridinium (MPP+). We demonstrate that the higher level of neurotoxicity in SN than VTA neurons was due to SN neuron-specific toxin-induced increase in cytosolic dopamine (DA) and Ca2+, followed by an elevation of mitochondrial Ca2+, activation of nitric oxide synthase (NOS), and mitochondrial oxidation. The increase in cytosolic Ca2+ was not caused by MPP+-induced oxidative stress, but rather depended on the activity of both L-type calcium channels and aSyn expression, suggesting that these two established pathogenic factors in PD act in concert.
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Affiliation(s)
- Ori J. Lieberman
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Se Joon Choi
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Ellen Kanter
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Anastasia Saverchenko
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Micah D. Frier
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Giulia M. Fiore
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Min Wu
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
| | - Jyothisri Kondapalli
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Enrico Zampese
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - D. James Surmeier
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - David Sulzer
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
- Department of Pharmacology, Columbia University Medical Center, New York, NY 10032
| | - Eugene V. Mosharov
- New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Medical Center, New York, NY 10032
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15
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Cerebral ischemic injury decreases α-synuclein expression in brain tissue and glutamate-exposed HT22 cells. Lab Anim Res 2017; 33:244-250. [PMID: 29046700 PMCID: PMC5645603 DOI: 10.5625/lar.2017.33.3.244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 11/21/2022] Open
Abstract
α-Synuclein is abundantly expressed in neuronal tissue, plays an essential role in the pathogenesis of neurodegenerative disorders, and exerts a neuroprotective effect against oxidative stress. Cerebral ischemia causes severe neurological disorders and neuronal dysfunction. In this study, we examined α-synuclein expression in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury and neuronal cells damaged by glutamate treatment. MCAO surgical operation was performed on male Sprague-Dawley rats, and brain samples were isolated 24 hours after MCAO. We confirmed neurological behavior deficit, infarction area, and histopathological changes following MCAO injury. A proteomic approach and Western blot analysis demonstrated a decrease in α-synuclein in the cerebral cortices after MCAO injury. Moreover, glutamate treatment induced neuronal cell death and decreased α-synuclein expression in a hippocampal-derived cell line in a dose-dependent manner. It is known that α-synuclein regulates neuronal survival, and low levels of α-synuclein expression result in cytotoxicity. Thus, these results suggest that cerebral ischemic injury leads to a reduction in α-synuclein and consequently causes serious brain damage.
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16
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Menges S, Minakaki G, Schaefer PM, Meixner H, Prots I, Schlötzer-Schrehardt U, Friedland K, Winner B, Outeiro TF, Winklhofer KF, von Arnim CAF, Xiang W, Winkler J, Klucken J. Alpha-synuclein prevents the formation of spherical mitochondria and apoptosis under oxidative stress. Sci Rep 2017; 7:42942. [PMID: 28224980 PMCID: PMC5320486 DOI: 10.1038/srep42942] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/17/2017] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress (OS), mitochondrial dysfunction, and dysregulation of alpha-synuclein (aSyn) homeostasis are key pathogenic factors in Parkinson's disease. Nevertheless, the role of aSyn in mitochondrial physiology remains elusive. Thus, we addressed the impact of aSyn specifically on mitochondrial response to OS in neural cells. We characterize a distinct type of mitochondrial fragmentation, following H2O2 or 6-OHDA-induced OS, defined by spherically-shaped and hyperpolarized mitochondria, termed "mitospheres". Mitosphere formation mechanistically depended on the fission factor Drp1, and was paralleled by reduced mitochondrial fusion. Furthermore, mitospheres were linked to a decrease in mitochondrial activity, and preceded Caspase3 activation. Even though fragmentation of dysfunctional mitochondria is considered to be a prerequisite for mitochondrial degradation, mitospheres were not degraded via Parkin-mediated mitophagy. Importantly, we provide compelling evidence that aSyn prevents mitosphere formation and reduces apoptosis under OS. In contrast, aSyn did not protect against Rotenone, which led to a different, previously described donut-shaped mitochondrial morphology. Our findings reveal a dichotomic role of aSyn in mitochondrial biology, which is linked to distinct types of stress-induced mitochondrial fragmentation. Specifically, aSyn may be part of a cellular defense mechanism preserving neural mitochondrial homeostasis in the presence of increased OS levels, while not protecting against stressors directly affecting mitochondrial function.
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Affiliation(s)
- Stefanie Menges
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Georgia Minakaki
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | | | - Holger Meixner
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Iryna Prots
- IZKF Junior Research Group III and BMBF Research Group Neuroscience, IZKF, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany.,Department of Stem Cell Biology, Institute of Human Genetics, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | | | - Kristina Friedland
- Molecular and Clinical Pharmacy, Department of Chemistry and Pharmacy, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Beate Winner
- IZKF Junior Research Group III and BMBF Research Group Neuroscience, IZKF, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany.,Department of Stem Cell Biology, Institute of Human Genetics, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Tiago F Outeiro
- Department of Neurodegeneration and Restorative Research, University Medical Center Göttingen, 37073 Göttingen, Germany.,Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
| | - Konstanze F Winklhofer
- Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | | | - Wei Xiang
- Institute of Biochemistry, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Jürgen Winkler
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Jochen Klucken
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
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Abstract
INTRODUCTION Parkinson's disease (PD) is an insidious disorder affecting more than 1-2% of the population over the age of 65. Understanding the etiology of PD may create opportunities for developing new treatments. Genomic and transcriptomic studies are useful, but do not provide evidence for the actual status of the disease. Conversely, proteomic studies deal with proteins, which are real time players, and can hence provide information on the dynamic nature of the affected cells. The number of publications relating to the proteomics of PD is vast. Therefore, there is a need to evaluate the current proteomics literature and establish the connections between the past and the present to foresee the future. Areas covered: PubMed and Web of Science were used to retrieve the literature associated with PD proteomics. Studies using human samples, model organisms and cell lines were selected and reviewed to highlight their contributions to PD. Expert commentary: The proteomic studies associated with PD achieved only limited success in facilitating disease diagnosis, monitoring and progression. A global system biology approach using new models is needed. Future research should integrate the findings of proteomics with other omics data to facilitate both early diagnosis and the treatment of PD.
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Affiliation(s)
- Murat Kasap
- a Department of Medical Biology/DEKART Proteomics Laboratory , Kocaeli University Medical School , Kocaeli , Turkey
| | - Gurler Akpinar
- a Department of Medical Biology/DEKART Proteomics Laboratory , Kocaeli University Medical School , Kocaeli , Turkey
| | - Aylin Kanli
- a Department of Medical Biology/DEKART Proteomics Laboratory , Kocaeli University Medical School , Kocaeli , Turkey
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18
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Nuclear Accumulation of Histone Deacetylase 4 (HDAC4) Exerts Neurotoxicity in Models of Parkinson’s Disease. Mol Neurobiol 2016; 54:6970-6983. [DOI: 10.1007/s12035-016-0199-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/11/2016] [Indexed: 12/18/2022]
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Alpha-synuclein-induced oxidative stress correlates with altered superoxide dismutase and glutathione synthesis in human neuroblastoma SH-SY5Y cells. Arch Toxicol 2016; 91:1245-1259. [PMID: 27424009 DOI: 10.1007/s00204-016-1788-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 07/05/2016] [Indexed: 10/21/2022]
Abstract
Alpha-synuclein (α-syn) is a major component of Lewy bodies found in sporadic and inherited forms of Parkinson's disease (PD). Mutations in the gene encoding α-syn and duplications and triplications of wild-type (WT) α-syn have been associated with PD. Several mechanisms have been implicated in the degeneration of dopaminergic neurons in PD, including oxidative stress and mitochondrial dysfunction. Here we defined the occurrence of oxidative stress in SH-SY5Y cells overexpressing WT α-syn in a doxycycline (Dox) regulated manner, before and after exposure to iron (500 µM), and determined the changes in proteins involved in the intracellular antioxidant defense system. Data evidenced an increase in caspase-3 activation and diminished reducing capacity of -Dox cells, associated with decreased activity of mitochondria complex I and reduced mitochondrial transcription factor A (TFAM) levels in these cells. Furthermore, total and mitochondrial reactive oxygen species levels were higher under basal conditions in cells overexpressing α-syn (-Dox) and this increase was apparently correlated with diminished levels and activities of SOD1 and SOD2 in -Dox cells. Moreover, both reduced and oxidized glutathione levels were diminished in -Dox cells under basal conditions, concomitantly with decreased activity of GCL and reduced protein levels of GCLc. The effects caused by iron (500 µM) were mostly independent of α-syn expression and triggered different antioxidant responses to possibly counterbalance higher levels of free radicals. Overall, data suggest that overexpression of α-syn modifies the antioxidant capacity of SH-SY5Y cells due to altered activity and protein levels of SOD1 and SOD2, and decreased glutathione pool.
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20
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Wang F, Yu SY, Zuo LJ, Cao CJ, Hu Y, Chen ZJ, Piao YS, Wang YJ, Wang XM, Chen SD, Chan P, Zhang W. Excessive Iron and α-Synuclein Oligomer in Brain are Relevant to Pure Apathy in Parkinson Disease. J Geriatr Psychiatry Neurol 2016; 29:187-94. [PMID: 26940028 DOI: 10.1177/0891988716632918] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/12/2016] [Indexed: 01/05/2023]
Abstract
OBJECTIVES To investigate the demographic features, clinical features, and potential mechanism in patients with Parkinson disease (PD) with pure apathy. METHOD A total of 145 patients with PD without depression and dementia and 30 age-matched controls were consecutively recruited. Patients with PD were evaluated by Apathy Scale (AS), scales for motor symptoms and quality of life. The levels of iron, oxidative and neuroinflammatory factors, α-synuclein oligomer, and dopamine in cerebrospinal fluid (CSF) from patients with PD and controls were detected by enzyme-linked immunosorbent assay, chemical colorimetric method, and high-performance liquid chromatography. Comparisons between PD with pure apathy and with no pure apathy groups and correlation between AS score and the levels of above factors were analyzed. RESULTS There were 64 (44.14%) cases in PD-apathy group. The PD-apathy group had older age, (97.81 ± 10.82) years versus (61.86 ± 10.80) years, and severer quality of life (P < .05). The PD-apathy and PD without apathy groups presented no remarkable differences in motor symptoms (P > .05). The levels of iron, hydroxyl radical (·OH), hydrogen peroxide (H2O2), and α-synuclein oligomer in CSF in PD-apathy group were significantly higher than that in PD without the apathy group (P < .05). In patients with PD, the AS score was positively correlated with the levels of iron, ·OH, H2O2 and α-synuclein oligomer in CSF (r = 19.838, .063, 1.046, and 0.498, respectively, P < .05). In PD-apathy group, iron level was positively correlated with ·OH level (r = .011, P < .05), and H2O2 level was positively correlated with α-synuclein oligomer level in CSF (r = .045, P < .05). CONCLUSION Patients with PD had high prevalence of pure apathy. Patients with PD having pure apathy had older age. Pure apathy reduced quality of life for patients without worsening motor function. Excessive iron and α-synuclein oligomer in brain commonly contributed to pure apathy of PD through potential mechanism of oxidative stress.
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Affiliation(s)
- Fang Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shu-Yang Yu
- Department of Geriatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Li-Jun Zuo
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chen-Jie Cao
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yang Hu
- Department of Geriatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ze-Jie Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ying-Shan Piao
- Department of Geriatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ya-Jie Wang
- Core Laboratory for Clinical Medical Research, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiao-Min Wang
- Department of Physiology, Capital Medical University, Beijing, China
| | - Sheng-Di Chen
- Department of Neurology, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Piu Chan
- Department of Neurology, Beijing Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wei Zhang
- Department of Geriatrics, Beijing Tiantan Hospital, Capital Medical University, Beijing, China Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China China National Clinical Research Center for Neurological Diseases, Beijing, China Center of Parkinson's Disease, Beijing Institute for Brain Disorders, Beijing, China Beijing Key Laboratory on Parkinson's Disease, Beijing, China
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21
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Butler B, Sambo D, Khoshbouei H. Alpha-synuclein modulates dopamine neurotransmission. J Chem Neuroanat 2016; 83-84:41-49. [PMID: 27334403 DOI: 10.1016/j.jchemneu.2016.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/03/2016] [Accepted: 06/11/2016] [Indexed: 01/13/2023]
Abstract
Alpha-synuclein is a small, highly charged protein encoded by the synuclein or SNCA gene that is predominantly expressed in central nervous system neurons. Although its physiological function remains enigmatic, alpha-synuclein is implicated in movement disorders such as Parkinson's disease, multiple system atrophy, and in neurodegenerative diseases such as Dementia with Lewy bodies. Here we have focused on reviewing the existing literature pertaining to wild-type alpha-synuclein structure, its properties, and its potential involvement in regulation of dopamine neurotransmission.
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Affiliation(s)
- Brittany Butler
- University of Florida, Department of Neuroscience and Department of Psychiatry Gainesville, FL 32611
| | - Danielle Sambo
- University of Florida, Department of Neuroscience and Department of Psychiatry Gainesville, FL 32611
| | - Habibeh Khoshbouei
- University of Florida, Department of Neuroscience and Department of Psychiatry Gainesville, FL 32611.
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22
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Benskey MJ, Perez RG, Manfredsson FP. The contribution of alpha synuclein to neuronal survival and function - Implications for Parkinson's disease. J Neurochem 2016; 137:331-59. [PMID: 26852372 PMCID: PMC5021132 DOI: 10.1111/jnc.13570] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 02/06/2023]
Abstract
The aggregation of alpha synuclein (α-syn) is a neuropathological feature that defines a spectrum of disorders collectively termed synucleinopathies, and of these, Parkinson's disease (PD) is arguably the best characterized. Aggregated α-syn is the primary component of Lewy bodies, the defining pathological feature of PD, while mutations or multiplications in the α-syn gene result in familial PD. The high correlation between α-syn burden and PD has led to the hypothesis that α-syn aggregation produces toxicity through a gain-of-function mechanism. However, α-syn has been implicated to function in a diverse range of essential cellular processes such as the regulation of neurotransmission and response to cellular stress. As such, an alternative hypothesis with equal explanatory power is that the aggregation of α-syn results in toxicity because of a toxic loss of necessary α-syn function, following sequestration of functional forms α-syn into insoluble protein aggregates. Within this review, we will provide an overview of the literature linking α-syn to PD and the knowledge gained from current α-syn-based animal models of PD. We will then interpret these data from the viewpoint of the α-syn loss-of-function hypothesis and provide a potential mechanistic model by which loss of α-syn function could result in at least some of the neurodegeneration observed in PD. By providing an alternative perspective on the etiopathogenesis of PD and synucleinopathies, this may reveal alternative avenues of research in order to identify potential novel therapeutic targets for disease modifying strategies. The correlation between α-synuclein burden and Parkinson's disease pathology has led to the hypothesis that α-synuclein aggregation produces toxicity through a gain-of-function mechanism. However, in this review, we discuss data supporting the alternative hypothesis that the aggregation of α-synuclein results in toxicity because of loss of necessary α-synuclein function at the presynaptic terminal, following sequestration of functional forms of α-synuclein into aggregates.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Ruth G Perez
- Department of Biomedical Sciences, Center of Emphasis in Neuroscience, Paul L. Foster School of Medicine, Texas Tech University of the Health Sciences El Paso, El Paso, Texas, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
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23
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Lewis YE, Abeywardana T, Lin YH, Galesic A, Pratt MR. Synthesis of a Bis-thio-acetone (BTA) Analogue of the Lysine Isopeptide Bond and its Application to Investigate the Effects of Ubiquitination and SUMOylation on α-Synuclein Aggregation and Toxicity. ACS Chem Biol 2016; 11:931-42. [PMID: 26726734 DOI: 10.1021/acschembio.5b01042] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The reversible modification of protein by the small protein ubiquitin and other ubiquitin-like modifiers plays important roles in virtually every key biological process in eukaryotic cells. The establishment of a range of chemical methods for the preparation of ubiquitinated proteins has enabled the site-specific interrogation of the consequences of these modifications. However, many of these techniques require significant levels of synthetic expertise, somewhat limiting their widespread application by the biological community. To overcome this issue, the creation of structural analogues of the ubiquitin-protein linkage that can be readily prepared with commercially available reagents and buffers is an important goal. Here we present the development of conditions for the facile synthesis of bis-thio-acetone (BTA) linkages of ubiquitinated proteins in high yields. Additionally, we apply this technique to the preparation of the aggregation prone protein α-synuclein bearing either ubiquitin or the small ubiquitin-like modifier (SUMO). With these proteins, we demonstrate that the BTA linkage recapitulates the previously published effects of either of these proteins on α-synuclein, suggesting that it is a good structural mimic. Notably, the BTA linkage is chemically and enzymatically stable, enabling us to study the consequences of site-specific ubiquitination and SUMOylation on the toxicity of α-synuclein in cell culture, which revealed modification and site-specific differences.
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Affiliation(s)
- Yuka E. Lewis
- Departments of Chemistry and ‡Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
| | - Tharindumala Abeywardana
- Departments of Chemistry and ‡Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
| | - Yu Hsuan Lin
- Departments of Chemistry and ‡Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
| | - Ana Galesic
- Departments of Chemistry and ‡Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
| | - Matthew R. Pratt
- Departments of Chemistry and ‡Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
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Marmolino D, Foerch P, Atienzar FA, Staelens L, Michel A, Scheller D. Alpha synuclein dimers and oligomers are increased in overexpressing conditions in vitro and in vivo. Mol Cell Neurosci 2015; 71:92-101. [PMID: 26711807 DOI: 10.1016/j.mcn.2015.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/03/2015] [Accepted: 12/16/2015] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta along with the formation of intracellular fibrillar inclusions (Lewy bodies and Lewy neuritis), which are mainly composed of aggregated α-synuclein (ASYN). This latter is a 14 kDa protein that localizes to synaptic vesicles in nerve terminals and promotes soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex assembly. We explored the monomeric and oligomeric state of ASYN in vitro in HEK293s and SH-SY5Y cell lines. In addition rats were injected in the substantia nigra with an Adeno associated virus carrying the human A53T mutation of ASYN (in vivo experiments). We show that human wild type ASYN as well as PD-linked mutations (A30P, E46K and A53T) in overexpressing conditions mostly exists in a monomeric state in equilibrium with dimeric forms. The monomer/dimer ratio is unaffected by PD-linked mutation. Furthermore, the A30P, E46K and A53T mutations overexpression strongly increased cell death compared to wild type ASYN. Taken together, our data suggest that ASYN dimers amount do not directly correlate to reduced cellular viability, suggesting a different role in protein function and induced pathology. Our data suggest that early ASYN neuro-pathogenic effects are probably mediated by other molecular processes than increased oligomerization alone.
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Affiliation(s)
- D Marmolino
- UCB Biopharma S.P.R.L., Neuroscience TA, Chemin du Foriest B-1420 Braine l'Alleud, Belgium.
| | - P Foerch
- UCB Biopharma S.P.R.L., Molecular Biology & Gene Expression, Discovery Research, Chemin du Foriest B-1420 Braine l'Alleud, Belgium
| | - F A Atienzar
- UCB Biopharma S.P.R.L., Non-Clinical Development, Chemin du Foriest B-1420 Braine l'Alleud, Belgium
| | - L Staelens
- UCB Biopharma S.P.R.L., Neuroscience TA, Chemin du Foriest B-1420 Braine l'Alleud, Belgium
| | - A Michel
- UCB Biopharma S.P.R.L., Neuroscience TA, Chemin du Foriest B-1420 Braine l'Alleud, Belgium
| | - D Scheller
- UCB Biopharma S.P.R.L., Neuroscience TA, Chemin du Foriest B-1420 Braine l'Alleud, Belgium
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25
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O-GlcNAc modification blocks the aggregation and toxicity of the protein α-synuclein associated with Parkinson's disease. Nat Chem 2015; 7:913-20. [PMID: 26492012 PMCID: PMC4618406 DOI: 10.1038/nchem.2361] [Citation(s) in RCA: 199] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 08/28/2015] [Indexed: 01/02/2023]
Abstract
Several aggregation-prone proteins associated with neurodegenerative diseases can be modified by O-linked N-acetyl-glucosamine (O-GlcNAc) in vivo. One of these proteins, α-synuclein, is a toxic aggregating protein associated with synucleinopathies, including Parkinson's disease. However, the effect of O-GlcNAcylation on α-synuclein is not clear. Here, we use synthetic protein chemistry to generate both unmodified α-synuclein and α-synuclein bearing a site-specific O-GlcNAc modification at the physiologically relevant threonine residue 72. We show that this single modification has a notable and substoichiometric inhibitory effect on α-synuclein aggregation, while not affecting the membrane binding or bending properties of α-synuclein. O-GlcNAcylation is also shown to affect the phosphorylation of α-synuclein in vitro and block the toxicity of α-synuclein that was exogenously added to cells in culture. These results suggest that increasing O-GlcNAcylation may slow the progression of synucleinopathies and further support a general function for O-GlcNAc in preventing protein aggregation.
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Bai X, Wey MCY, Fernandez E, Hart MJ, Gelfond J, Bokov AF, Rani S, Strong R. Rapamycin improves motor function, reduces 4-hydroxynonenal adducted protein in brain, and attenuates synaptic injury in a mouse model of synucleinopathy. PATHOBIOLOGY OF AGING & AGE RELATED DISEASES 2015; 5:28743. [PMID: 26306821 PMCID: PMC4549373 DOI: 10.3402/pba.v5.28743] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/03/2015] [Accepted: 07/03/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND Synucleinopathy is any of a group of age-related neurodegenerative disorders including Parkinson's disease, multiple system atrophy, and dementia with Lewy Bodies, which is characterized by α-synuclein inclusions and parkinsonian motor deficits affecting millions of patients worldwide. But there is no cure at present for synucleinopathy. Rapamycin has been shown to be neuroprotective in several in vitro and in vivo synucleinopathy models. However, there are no reports on the long-term effects of RAPA on motor function or measures of neurodegeneration in models of synucleinopathy. METHODS We determined whether long-term feeding a rapamycin diet (14 ppm in diet; 2.25 mg/kg body weight/day) improves motor function in neuronal A53T α-synuclein transgenic mice (TG) and explored underlying mechanisms using a variety of behavioral and biochemical approaches. RESULTS After 24 weeks of treatment, rapamycin improved performance on the forepaw stepping adjustment test, accelerating rotarod and pole test. Rapamycin did not alter A53T α-synuclein content. There was no effect of rapamycin treatment on midbrain or striatal monoamines or their metabolites. Proteins adducted to the lipid peroxidation product 4-hydroxynonenal were decreased in brain regions of both wild-type and TG mice treated with rapamycin. Reduced levels of the presynaptic marker synaptophysin were found in several brain regions of TG mice. Rapamycin attenuated the loss of synaptophysin protein in the affected brain regions. Rapamycin also attenuated the loss of synaptophysin protein and prevented the decrease of neurite length in SH-SY5Y cells treated with 4-hydroxynonenal. CONCLUSION Taken together, these data suggest that rapamycin, an FDA approved drug, may prove useful in the treatment of synucleinopathy.
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Affiliation(s)
- Xiang Bai
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Margaret Chia-Ying Wey
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Elizabeth Fernandez
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care Network, San Antonio, TX, USA
| | - Matthew J Hart
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- High Throughput Screening Facility, Center for Innovative Drug Discovery University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Jonathan Gelfond
- Department of Epidemiology & Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Alex F Bokov
- Department of Epidemiology & Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sheela Rani
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Randy Strong
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care Network, San Antonio, TX, USA;
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Electron Transport Disturbances and Neurodegeneration: From Albert Szent-Györgyi's Concept (Szeged) till Novel Approaches to Boost Mitochondrial Bioenergetics. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:498401. [PMID: 26301042 PMCID: PMC4537740 DOI: 10.1155/2015/498401] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 04/15/2015] [Indexed: 12/21/2022]
Abstract
Impaired function of certain mitochondrial respiratory complexes has long been linked to the pathogenesis of chronic neurodegenerative disorders such as Parkinson's and Huntington's diseases. Furthermore, genetic alterations of mitochondrial genome or nuclear genes encoding proteins playing essential roles in maintaining proper mitochondrial function can lead to the development of severe systemic diseases associated with neurodegeneration and vacuolar myelinopathy. At present, all of these diseases lack effective disease modifying therapy. Following a brief commemoration of Professor Albert Szent-Györgyi, a Nobel Prize laureate who pioneered in the field of cellular respiration, antioxidant processes, and the roles of free radicals in health and disease, the present paper overviews the current knowledge on the involvement of mitochondrial dysfunction in central nervous system diseases associated with neurodegeneration including Parkinson's and Huntington's disease as well as mitochondrial encephalopathies. The review puts special focus on the involvement and the potential therapeutic relevance of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), a nuclear-encoded master regulator of mitochondrial biogenesis and antioxidant responses in these disorders, the transcriptional activation of which may hold novel therapeutic value as a more system-based approach aiming to restore mitochondrial functions in neurodegenerative processes.
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Song LK, Ma KL, Yuan YH, Mu Z, Song XY, Niu F, Han N, Chen NH. Targeted Overexpression of α-Synuclein by rAAV2/1 Vectors Induces Progressive Nigrostriatal Degeneration and Increases Vulnerability to MPTP in Mouse. PLoS One 2015; 10:e0131281. [PMID: 26114655 PMCID: PMC4483255 DOI: 10.1371/journal.pone.0131281] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 06/01/2015] [Indexed: 12/12/2022] Open
Abstract
Mutations, duplication and triplication of α-synuclein genes are linked to familial Parkinson's disease (PD), and aggregation of α-synuclein (α-syn) in Lewy bodies (LB) is involved in the pathogenesis of the disease. The targeted overexpression of α-syn in the substantia nigra (SN) mediated by viral vectors may provide a better alternative to recapitulate the neurodegenerative features of PD. Therefore, we overexpressed human wild-type α-syn using rAAV2/1 vectors in the bilateral SN of mouse and examined the effects for up to 12 weeks. Delivery of rAAV-2/1-α-syn caused significant nigrostriatal degeneration including appearance of dystrophic striatal neurites, loss of nigral dopaminergic (DA) neurons and dissolving nigral neuron bodies in a time-dependent manner. In addition, the α-syn overexpressed mice also developed significant deficits in motor function at 12 weeks when the loss of DA neurons exceeded a threshold of 50%. To investigate the sensitivity to neurotoxins in mice overexpressing α-syn, we performed an MPTP treatment with the subacute regimen 8 weeks after rAAV injection. The impact of the combined genetic and environmental insults on DA neuronal loss, striatal dopamine depletion, dopamine turnover and motor dysfunction was markedly greater than that of either alone. Moreover, we observed increased phosphorylation (S129), accumulation and nuclear distribution of α-syn after the combined insults. In summary, these results reveal that the overexpressed α-syn induces progressive nigrostriatal degeneration and increases the susceptibility of DA neurons to MPTP. Therefore, the targeted overexpression of α-syn and the combination with environmental toxins may provide valuable models for understanding PD pathogenesis and developing related therapies.
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Affiliation(s)
- Lian-Kun Song
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Kai-Li Ma
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Yu-He Yuan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Zheng Mu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Xiu-Yun Song
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Fei Niu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Ning Han
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China
- Hunan University of Chinese Medicine, Changsha, 410208, China
- * E-mail:
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Stojkovska I, Wagner BM, Morrison BE. Parkinson's disease and enhanced inflammatory response. Exp Biol Med (Maywood) 2015; 240:1387-95. [PMID: 25769314 DOI: 10.1177/1535370215576313] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 01/21/2015] [Indexed: 11/16/2022] Open
Abstract
Parkinson's disease (PD) is the first and second most prevalent motor and neurodegenerative disease, respectively. The clinical symptoms of PD result from a loss of midbrain dopaminergic (DA) neurons. However, the molecular cause of DA neuron loss remains elusive. Mounting evidence implicates enhanced inflammatory response in the development and progression of PD pathology. This review examines current research connecting PD and inflammatory response.
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Affiliation(s)
- Iva Stojkovska
- Department of Biological Sciences, Boise State University, Boise, ID 83725-1515, USA
| | - Brandon M Wagner
- Department of Biological Sciences, Boise State University, Boise, ID 83725-1515, USA
| | - Brad E Morrison
- Department of Biological Sciences, Boise State University, Boise, ID 83725-1515, USA
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Harischandra DS, Jin H, Anantharam V, Kanthasamy A, Kanthasamy AG. α-Synuclein protects against manganese neurotoxic insult during the early stages of exposure in a dopaminergic cell model of Parkinson's disease. Toxicol Sci 2014; 143:454-68. [PMID: 25416158 DOI: 10.1093/toxsci/kfu247] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The pathological role of α-synuclein (α-Syn) aggregation in neurodegeneration is well recognized, but the physiological function of normal α-Syn remains unknown. As α-Syn protein contains multiple divalent metal binding sites, herein we conducted a comprehensive characterization of the role of α-Syn in manganese-induced dopaminergic neurotoxicity. We established transgenic N27 dopaminergic neuronal cells by stably expressing human wild-type α-Syn at normal physiological levels. α-Syn-expressing dopaminergic cells significantly attenuated Mn-induced neurotoxicity for 24-h exposures relative to vector control cells. To further explore cellular mechanisms, we studied the mitochondria-dependent apoptotic pathway. Analysis of a key mitochondrial apoptotic initiator, cytochrome c, revealed that α-Syn significantly reduces the Mn-induced cytochrome c release into cytosol. The downstream caspase cascade, involving caspase-9 and caspase-3 activation, during Mn exposure was also largely attenuated in Mn-treated α-Syn cells in a time-dependent manner. α-Syn cells also showed a dramatic reduction in the Mn-induced proteolytic activation of the pro-apoptotic kinase PKCδ. The generation of Mn-induced reactive oxygen species (ROS) did not differ between α-Syn and vector control cells, indicating that α-Syn exerts its protective effect independent of altering ROS generation. Inductively coupled plasma-mass spectrometry (ICP-MS) revealed no significant differences in intracellular Mn levels between treated vector and α-Syn cells. Notably, the expression of wild-type α-Syn in primary mesencephalic cells also rescued cells from Mn-induced neurotoxicity. However, prolonged exposure to Mn promoted protein aggregation in α-Syn-expressing cells. Collectively, these results demonstrate that wild-type α-Syn exhibits neuroprotective effects against Mn-induced neurotoxicity during the early stages of exposure in a dopaminergic neuronal model of PD.
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Affiliation(s)
- Dilshan S Harischandra
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, Iowa 50011
| | - Huajun Jin
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, Iowa 50011
| | - Vellareddy Anantharam
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, Iowa 50011
| | - Arthi Kanthasamy
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, Iowa 50011
| | - Anumantha G Kanthasamy
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, Iowa 50011
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Bir A, Sen O, Anand S, Khemka VK, Banerjee P, Cappai R, Sahoo A, Chakrabarti S. α-Synuclein-induced mitochondrial dysfunction in isolated preparation and intact cells: implications in the pathogenesis of Parkinson's disease. J Neurochem 2014; 131:868-77. [PMID: 25319443 DOI: 10.1111/jnc.12966] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/24/2014] [Accepted: 09/25/2014] [Indexed: 11/26/2022]
Abstract
This study has shown that purified recombinant human α-synuclein (20 μM) causes membrane depolarization and loss of phosphorylation capacity of isolated purified rat brain mitochondria by activating permeability transition pore complex. In intact SHSY5Y (human neuroblastoma cell line) cells, lactacystin (5 μM), a proteasomal inhibitor, causes an accumulation of α-synuclein with concomitant mitochondrial dysfunction and cell death. The effects of lactacystin on intact SHSY5Y cells are, however, prevented by knocking down α-synuclein expression by specific siRNA. Furthermore, in wild-type (non-transfected) SHSY5Y cells, the effects of lactacystin on mitochondrial function and cell viability are also prevented by cyclosporin A (1 μM) which blocks the activity of the mitochondrial permeability transition pore. Likewise, in wild-type SHSY5Y cells, typical mitochondrial poison like antimycin A (50 nM) produces loss of cell viability comparable to that of lactacystin (5 μM). These data, in combination with those from isolated brain mitochondria, strongly suggest that intracellularly accumulated α-synuclein can interact with mitochondria in intact SHSY5Y cells causing dysfunction of the organelle which drives the cell death under our experimental conditions. The results have clear implications in the pathogenesis of sporadic Parkinson's disease. α-Synuclein is shown to cause mitochondrial impairment through interaction with permeability transition pore complex in isolated preparations. Intracellular accumulation of α-synuclein in SHSY5Y cells following proteasomal inhibition leads to mitochondrial impairment and cell death which could be prevented by knocking down α-synuclein gene. The results link mitochondrial dysfunction and α-synuclein accumulation, two key pathogenic mechanisms of Parkinson's disease, in a common damage pathway.
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Affiliation(s)
- Aritri Bir
- Department of Biochemistry, Institute of Post Graduate Medical Education and Research, Kolkata, India
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Luth ES, Stavrovskaya IG, Bartels T, Kristal BS, Selkoe DJ. Soluble, prefibrillar α-synuclein oligomers promote complex I-dependent, Ca2+-induced mitochondrial dysfunction. J Biol Chem 2014; 289:21490-507. [PMID: 24942732 DOI: 10.1074/jbc.m113.545749] [Citation(s) in RCA: 198] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
α-Synuclein (αSyn) aggregation and mitochondrial dysfunction both contribute to the pathogenesis of Parkinson disease (PD). Although recent studies have suggested that mitochondrial association of αSyn may disrupt mitochondrial function, it is unclear what aggregation state of αSyn is most damaging to mitochondria and what conditions promote or inhibit the effect of toxic αSyn species. Because the neuronal populations most vulnerable in PD are characterized by large cytosolic Ca(2+) oscillations that burden mitochondria, we examined mitochondrial Ca(2+) stress in an in vitro system comprising isolated mitochondria and purified recombinant human αSyn in various aggregation states. Using fluorimetry to simultaneously measure four mitochondrial parameters, we observed that soluble, prefibrillar αSyn oligomers, but not monomeric or fibrillar αSyn, decreased the retention time of exogenously added Ca(2+), promoted Ca(2+)-induced mitochondrial swelling and depolarization, and accelerated cytochrome c release. Inhibition of the permeability transition pore rescued these αSyn-induced changes in mitochondrial parameters. Interestingly, the mitotoxic effects of αSyn were specifically dependent upon both electron flow through complex I and mitochondrial uptake of exogenous Ca(2+). Our results suggest that soluble prefibrillar αSyn oligomers recapitulate several mitochondrial phenotypes previously observed in animal and cell models of PD: complex I dysfunction, altered membrane potential, disrupted Ca(2+) homeostasis, and enhanced cytochrome c release. These data reveal how the association of oligomeric αSyn with mitochondria can be detrimental to the function of cells with high Ca(2+)-handling requirements.
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Affiliation(s)
- Eric S Luth
- From the Center for Neurologic Diseases, Department of Neurology, and
| | - Irina G Stavrovskaya
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Tim Bartels
- From the Center for Neurologic Diseases, Department of Neurology, and
| | - Bruce S Kristal
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Dennis J Selkoe
- From the Center for Neurologic Diseases, Department of Neurology, and
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Khalaf O, Fauvet B, Oueslati A, Dikiy I, Mahul-Mellier AL, Ruggeri FS, Mbefo MK, Vercruysse F, Dietler G, Lee SJ, Eliezer D, Lashuel HA. The H50Q mutation enhances α-synuclein aggregation, secretion, and toxicity. J Biol Chem 2014; 289:21856-76. [PMID: 24936070 DOI: 10.1074/jbc.m114.553297] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Over the last two decades, the identification of missense mutations in the α-synuclein (α-Syn) gene SNCA in families with inherited Parkinson disease (PD) has reinforced the central role of α-Syn in PD pathogenesis. Recently, a new missense mutation (H50Q) in α-Syn was described in patients with a familial form of PD and dementia. Here we investigated the effects of this novel mutation on the biophysical properties of α-Syn and the consequences for its cellular function. We found that the H50Q mutation affected neither the structure of free or membrane-bound α-Syn monomer, its interaction with metals, nor its capacity to be phosphorylated in vitro. However, compared with the wild-type (WT) protein, the H50Q mutation accelerated α-Syn fibrillization in vitro. In cell-based models, H50Q mutation did not affect α-Syn subcellular localization or its ability to be phosphorylated by PLK2 and GRK6. Interestingly, H50Q increased α-Syn secretion from SHSY5Y cells into culture medium and induced more mitochondrial fragmentation in hippocampal neurons. Although the transient overexpression of WT or H50Q did not induce toxicity, both species induced significant cell death when added to the culture medium of hippocampal neurons. Strikingly, H50Q exhibited more toxicity, suggesting that the H50Q-related enhancement of α-Syn aggregation and secretion may play a role in the extracellular toxicity of this mutant. Together, our results provide novel insight into the mechanism by which this newly described PD-associated mutation may contribute to the pathogenesis of PD and related disorders.
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Affiliation(s)
- Ossama Khalaf
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Bruno Fauvet
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Abid Oueslati
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Igor Dikiy
- Department of Biochemistry, Program in Structural Biology, Weill Cornell Medical College, New York, New York 10065, and
| | - Anne-Laure Mahul-Mellier
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Francesco Simone Ruggeri
- Laboratory of Physics of Living Matter, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Martial K Mbefo
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Filip Vercruysse
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
| | - Giovanni Dietler
- Laboratory of Physics of Living Matter, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Seung-Jae Lee
- Department of Biomedical Science and Technology, Konkuk University, Seoul 143-701, South Korea
| | - David Eliezer
- Department of Biochemistry, Program in Structural Biology, Weill Cornell Medical College, New York, New York 10065, and
| | - Hilal A Lashuel
- From the Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute and
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Yan JQ, Yuan YH, Gao YN, Huang JY, Ma KL, Gao Y, Zhang WQ, Guo XF, Chen NH. Overexpression of human E46K mutant α-synuclein impairs macroautophagy via inactivation of JNK1-Bcl-2 pathway. Mol Neurobiol 2014; 50:685-701. [PMID: 24833599 DOI: 10.1007/s12035-014-8738-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 04/30/2014] [Indexed: 12/19/2022]
Abstract
Parkinson's disease (PD) is pathologically characterized by selective loss of dopaminergic neurons in the midbrain and the existence of intracellular protein inclusions termed Lewy bodies, largely composed of α-synuclein. Genetic studies have revealed that rare point mutations in the gene encoding α-synuclein including A30P, A53T, and E46K are associated with familial forms of PD, indicating a pathological role for mutant α-synuclein in PD etiology. However, the mechanisms underlying the neuronal toxicity of mutant α-synuclein are still to be elucidated. Growing evidence has suggested a deleterious effect of mutant α-synuclein on the autophagy-lysosome pathway. In this study, we discovered that overexpression of human E46K mutant α-synuclein impaired macroautophagy in mammalian cells. Our data showed that overexpression of E46K mutant α-synuclein impaired autophagy at an early stage of autophagosome formation via the c-Jun N-terminal kinase 1 (JNK1)-Bcl-2 but not the mammalian target of rapamycin (mTOR) pathway. Overexpressed E46K mutant α-synuclein inhibited JNK1 activation, leading to a reduced Bcl-2 phosphorylation and increased association between Bcl-2 and Beclin1, further disrupting the formation of Beclin1/hVps34 complex, which is essential for autophagy initiation. Furthermore, overexpression of E46K mutant α-synuclein increased the vulnerability of differentiated PC12 cells to rotenone treatment, which would be partly due to its inhibitory effects on autophagy. Our findings may shed light on the potential roles of mutant α-synuclein in the pathogenesis of PD.
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Affiliation(s)
- Jia-Qing Yan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, I Xiannongtan Street, Xicheng District, 100050, Beijing, People's Republic of China
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Bornhorst J, Chakraborty S, Meyer S, Lohren H, Brinkhaus SG, Knight AL, Caldwell KA, Caldwell GA, Karst U, Schwerdtle T, Bowman A, Aschner M. The effects of pdr1, djr1.1 and pink1 loss in manganese-induced toxicity and the role of α-synuclein in C. elegans. Metallomics 2014; 6:476-90. [PMID: 24452053 DOI: 10.1039/c3mt00325f] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative brain disorder characterized by selective dopaminergic (DAergic) cell loss that results in overt motor and cognitive deficits. Current treatment options exist to combat PD symptomatology, but are unable to directly target its pathogenesis due to a lack of knowledge concerning its etiology. Several genes have been linked to PD, including three genes associated with an early-onset familial form: parkin, pink1 and dj1. All three genes are implicated in regulating oxidative stress pathways. Another hallmark of PD pathophysiology is Lewy body deposition, associated with the gain-of-function genetic risk factor α-synuclein. The function of α-synuclein is poorly understood, as it shows both neurotoxic and neuroprotective activities in PD. Using the genetically tractable invertebrate Caenorhabditis elegans (C. elegans) model system, the neurotoxic or neuroprotective role of α-synuclein upon acute Mn exposure in the background of mutated pdr1, pink1 or djr1.1 was examined. The pdr1 and djr1.1 mutants showed enhanced Mn accumulation and oxidative stress that was reduced by α-synuclein. Moreover, DAergic neurodegeneration, while unchanged with Mn exposure, returned to wild-type (WT) levels for pdr1, but not djr1.1 mutants expressing α-synuclein. Taken together, this study uncovers a novel, neuroprotective role for WT human α-synuclein in attenuating Mn-induced toxicity in the background of PD-associated genes, and further supports the role of extracellular dopamine in exacerbating Mn neurotoxicity.
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Affiliation(s)
- Julia Bornhorst
- Institute of Food Chemistry, University of Münster, Münster, Germany
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Fasano M, Lopiano L. α-synuclein and Parkinson’s disease: a proteomic view. Expert Rev Proteomics 2014; 5:239-48. [DOI: 10.1586/14789450.5.2.239] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Pienaar IS, Dexter DT, Burkhard PR. Mitochondrial proteomics as a selective tool for unraveling Parkinson’s disease pathogenesis. Expert Rev Proteomics 2014; 7:205-26. [DOI: 10.1586/epr.10.8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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38
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Bury A, Pienaar IS. Behavioral testing regimens in genetic-based animal models of Parkinson's disease: cogencies and caveats. Neurosci Biobehav Rev 2013; 37:846-59. [PMID: 23558176 DOI: 10.1016/j.neubiorev.2013.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/01/2013] [Accepted: 03/11/2013] [Indexed: 12/20/2022]
Abstract
Although the onset and progression of Parkinson's disease (PD) is fundamentally sporadic, identification of several of the genes implicated in the disease has provided significant insight concerning patho-physiological mechanisms potentially underlying sporadic PD. Moreover, such studies have caused a revolution in the way researchers view the disease. Since single genes responsible for rare familial forms of the disease have only been identified within the past few years, animal models based on these defects have only recently been generated, thereby not leaving a lot of time for their evaluation and subsequent improvement. The current article provides an extensive review of the major motor and non-motor behavioral tests used in genetically-induced Parkinsonian animals. Moreover, we assess the insights concerning the etiopathogenesis of PD generated from use of such tests and how these have improved available treatment strategies for alleviating aspects of sporadic and non-sporadic parkinsonism.
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Affiliation(s)
- Alexander Bury
- Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Department of Medicine, Imperial College London, United Kingdom
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Jiang T, Yu WB, Yao T, Zhi XL, Pan LF, Wang J, Zhou P. Trehalose inhibits wild-type α-synuclein fibrillation and overexpression and protects against the protein neurotoxicity in transduced PC12 cells. RSC Adv 2013. [DOI: 10.1039/c3ra40600h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Goldstein DS, Sullivan P, Cooney A, Jinsmaa Y, Sullivan R, Gross DJ, Holmes C, Kopin IJ, Sharabi Y. Vesicular uptake blockade generates the toxic dopamine metabolite 3,4-dihydroxyphenylacetaldehyde in PC12 cells: relevance to the pathogenesis of Parkinson's disease. J Neurochem 2012; 123:932-43. [PMID: 22906103 DOI: 10.1111/j.1471-4159.2012.07924.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/03/2012] [Accepted: 08/11/2012] [Indexed: 01/03/2023]
Abstract
Parkinson's disease entails profound loss of nigrostriatal dopaminergic terminals, decreased vesicular uptake of intraneuronal catecholamines, and relatively increased putamen tissue concentrations of the toxic dopamine metabolite, 3,4-dihydroxyphenylacetaldehyde (DOPAL). The objective of this study was to test whether vesicular uptake blockade augments endogenous DOPAL production. We also examined whether intracellular DOPAL contributes to apoptosis and, as α-synuclein oligomers may be pathogenetic in Parkinson's disease, oligomerizes α-synuclein. Catechols were assayed in PC12 cells after reserpine to block vesicular uptake, with or without inhibition of enzymes metabolizing DOPAL-daidzein for aldehyde dehydrogenase and AL1576 for aldehyde reductase. Vesicular uptake was quantified by a method based on 6F- or (13) C-dopamine incubation; DOPAL toxicity by apoptosis responses to exogenous dopamine, with or without daidzein+AL1576; and DOPAL--induced synuclein oligomerization by synuclein dimer production during DOPA incubation, with or without inhibition of L-aromatic-amino-acid decarboxylase or monoamine oxidase. Reserpine inhibited vesicular uptake by 95-97% and rapidly increased cell DOPAL content (p = 0.0008). Daidzein+AL1576 augmented DOPAL responses to reserpine (p = 0.004). Intracellular DOPAL contributed to dopamine-evoked apoptosis and DOPA-evoked synuclein dimerization. The findings fit with the 'catecholaldehyde hypothesis,' according to which decreased vesicular sequestration of cytosolic catecholamines and impaired catecholaldehyde detoxification contribute to the catecholaminergic denervation that characterizes Parkinson's disease.
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Affiliation(s)
- David S Goldstein
- Clinical Neurocardiology Section, CNP/DIR/NINDS/NIH, Bethesda, MD 20892-1620, USA.
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Béraud D, Hathaway HA, Trecki J, Chasovskikh S, Johnson DA, Johnson JA, Federoff HJ, Shimoji M, Mhyre TR, Maguire-Zeiss KA. Microglial activation and antioxidant responses induced by the Parkinson's disease protein α-synuclein. J Neuroimmune Pharmacol 2012; 8:94-117. [PMID: 23054368 PMCID: PMC3582877 DOI: 10.1007/s11481-012-9401-0] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 09/06/2012] [Indexed: 12/29/2022]
Abstract
Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder typified by tremor, rigidity, akinesia and postural instability due in part to the loss of dopamine within the nigrostriatal system. The pathologic features of this disorder include the loss of substantia nigra dopamine neurons and attendant striatal terminals, the presence of large protein-rich neuronal inclusions containing fibrillar α-synuclein and increased numbers of activated microglia. Evidence suggests that both misfolded α-synuclein and oxidative stress play an important role in the pathogenesis of sporadic PD. Here we review evidence that α-synuclein activates glia inducing inflammation and that Nrf2-directed phase-II antioxidant enzymes play an important role in PD. We also provide new evidence that the expression of antioxidant enzymes regulated in part by Nrf2 is increased in a mouse model of α-synuclein overexpression. We show that misfolded α-synuclein directly activates microglia inducing the production and release of the proinflammatory cytokine, TNF-α, and increasing antioxidant enzyme expression. Importantly, we demonstrate that the precise structure of α-synuclein is important for induction of this proinflammatory pathway. This complex α-synuclein-directed glial response highlights the importance of protein misfolding, oxidative stress and inflammation in PD and represents a potential locus for the development of novel therapeutics focused on induction of the Nrf2-directed antioxidant pathway and inhibition of protein misfolding.
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Affiliation(s)
- Dawn Béraud
- Department of Neuroscience, Georgetown University Medical Center, NRB EP08, 3970 Reservoir Road NW, Washington, DC 20057, USA
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Abstract
Dementias are a varied group of disorders typically associated with memory loss, impaired judgment and/or language and by symptoms affecting other cognitive and social abilities to a degree that interferes with daily functioning. Alzheimer's disease (AD) is the most common cause of a progressive dementia, followed by dementia with Lewy bodies (DLB), frontotemporal dementia (FTD), (VaD) and HIV-associated neurocognitive disorders (HAND). The pathogenesis of this group of disorders has been linked to the abnormal accumulation of proteins in the brains of affected individuals, which in turn has been related to deficits in protein clearance. Autophagy is a key cellular protein clearance pathway with proteolytic cleavage and degradation via the ubiquitin-proteasome pathway representing another important clearance mechanism. Alterations in the levels of autophagy and the proteins associated with the autophagocytic pathway have been reported in various types of dementias. This review will examine recent literature across these disorders and highlight a common theme of altered autophagy across the spectrum of the dementias.
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Oxidative stress in genetic mouse models of Parkinson's disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:624925. [PMID: 22829959 PMCID: PMC3399377 DOI: 10.1155/2012/624925] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/12/2012] [Accepted: 04/12/2012] [Indexed: 02/07/2023]
Abstract
There is extensive evidence in Parkinson's disease of a link between oxidative stress and some of the monogenically inherited Parkinson's disease-associated genes. This paper focuses on the importance of this link and potential impact on neuronal function. Basic mechanisms of oxidative stress, the cellular antioxidant machinery, and the main sources of cellular oxidative stress are reviewed. Moreover, attention is given to the complex interaction between oxidative stress and other prominent pathogenic pathways in Parkinson's disease, such as mitochondrial dysfunction and neuroinflammation. Furthermore, an overview of the existing genetic mouse models of Parkinson's disease is given and the evidence of oxidative stress in these models highlighted. Taken into consideration the importance of ageing and environmental factors as a risk for developing Parkinson's disease, gene-environment interactions in genetically engineered mouse models of Parkinson's disease are also discussed, highlighting the role of oxidative damage in the interplay between genetic makeup, environmental stress, and ageing in Parkinson's disease.
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Cardozo-Pelaez F, Sanchez-Contreras M, Nevin ABC. Ogg1 null mice exhibit age-associated loss of the nigrostriatal pathway and increased sensitivity to MPTP. Neurochem Int 2012; 61:721-30. [PMID: 22743193 DOI: 10.1016/j.neuint.2012.06.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 05/18/2012] [Accepted: 06/18/2012] [Indexed: 12/21/2022]
Abstract
Cumulative damage to cellular macromolecules via oxidative stress is a hallmark of aging and neurodegenerative disease. Whether such damage is a cause or a subsequent effect of neurodegeneration is still unknown. This paper describes the development of an age-associated mild parkinsonian model in mice that lack the DNA repair enzyme 8-oxoguanine glycosylase 1 (Ogg1). Aged OGG1 knock-out (OGG1 KO) mice show a decreased spontaneous locomotor behavior and evidence a decrease in striatal dopamine levels, a loss of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN), and an increase in ubiquitin-positive inclusions in their remaining SN neurons. In addition, young OGG1 KO mice are more susceptible to the dopaminergic toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) than their wild-type (WT) counterparts. Age-associated increases in 7,8-dihydro-2'-deoxyguanine (oxo(8)dG) have been reported in brain regions and neuronal populations affected in Parkinson's disease (PD), toxin-induced parkinsonian models, and mice harboring genetic abnormalities associated with PD. Because of these increased oxo(8)dG levels, the OGG1 KO mouse strain could shed light on molecular events leading to neuronal loss as a consequence of cumulative oxidative damage to DNA during aging and after toxicological challenge.
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Affiliation(s)
- Fernando Cardozo-Pelaez
- Center for Environmental Health Sciences, Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT 59812, USA.
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Dumitru I, Ene CD, Ofiteru AM, Paraschivescu C, Madalan AM, Baciu I, Farcasanu IC. Identification of [CuCl(acac)(tmed)], a copper(II) complex with mixed ligands, as a modulator of Cu,Zn superoxide dismutase (Sod1p) activity in yeast. J Biol Inorg Chem 2012; 17:961-74. [PMID: 22714120 DOI: 10.1007/s00775-012-0912-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/04/2012] [Indexed: 12/20/2022]
Abstract
Superoxide dismutases (SODs) stand in the prime line of enzymatic antioxidant defense in nearly all eukaryotic cells exposed to oxygen, catalyzing the breakdown of the superoxide anionic radical to O(2) and H(2)O(2). Overproduction of superoxide correlates with numerous pathophysiological conditions, and although the native enzyme can be used as a therapeutic agent in superoxide-associated conditions, synthetic low molecular weight mimetics are preferred in terms of cost, administration mode, and bioavailability. In this study we make use of the model eukaryote Saccharomyces cerevisiae to investigate the SOD-mimetic action of a mononuclear mixed-ligand copper(II) complex, [CuCl(acac)(tmed)] (where acac is acetylacetonate anion and tmed is N,N,N',N'-tetramethylethylenediamine). Taking advantage of an easily reproducible phenotype of yeast cells which lack Cu-Zn SOD (Sod1p), we found that the compound could act either as a superoxide scavenger in the absence of native Sod1p or as a Sod1p modulator which behaved differently under various genetic backgrounds.
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Affiliation(s)
- Ioana Dumitru
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Bucharest, Romania
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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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Li J, Yang J, Zhao P, Li S, Zhang R, Zhang X, Liu D, Zhang B. Neuromelanin enhances the toxicity of α-synuclein in SK-N-SH cells. J Neural Transm (Vienna) 2011; 119:685-91. [PMID: 22200858 DOI: 10.1007/s00702-011-0753-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
Abstract
The key pathological feature of Parkinson's disease (PD) is selective degeneration of the neuromelanin (NM)-pigmented dopaminergic neurons in the substantia nigra (SN). NM, like other risk factors, such as oxidative stress (OS) and α-synuclein (α-syn), is involved in the pathogenesis of PD. But whether or not NM synergizes with α-syn or OS in the pathogenesis of PD remains unexplored. In the present study, we examined the effects of NM on cellular viability, apoptosis and free radical production in α-syn over-expressing human neuroblastoma cell line (SK-N-SH) in the presence or absence of the oxidizer Fenton's Reagent (FR). We showed that NM synergized with FR in suppressing cell viability, and in inducing apoptosis and hydroxyl radical production in all SK-N-SH cell lines. α-Syn over-expressing cells exhibited more pronounced effect, especially the A53T mutation. Our findings suggest that NM synergizes with both OS and α-syn in conferring dopaminergic vulnerability, adding to our understanding of the pathogenesis of PD.
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Affiliation(s)
- Jie Li
- Department of Psychiatry, Tianjin Medical University, 22 Qixiangtai Road, Tianjin 300070, China.
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Bellucci A, Navarria L, Zaltieri M, Missale C, Spano P. α-Synuclein synaptic pathology and its implications in the development of novel therapeutic approaches to cure Parkinson's disease. Brain Res 2011; 1432:95-113. [PMID: 22153624 DOI: 10.1016/j.brainres.2011.11.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 11/11/2011] [Accepted: 11/11/2011] [Indexed: 12/24/2022]
Abstract
Parkinson's disease (PD) is characterized by a progressive loss of dopamine (DA) neurons of the nigrostriatal system and by the presence of Lewy bodies (LB), proteinaceous inclusions mainly composed of filamentous α-synuclein aggregates. Alpha-synuclein is a natively unfolded protein which plays a central role in the control of dopaminergic neuronal functions and which is thought to be critically implicated in PD pathophysiology. Indeed, besides the fact that α-synuclein is the main protein component of LB, genetic studies showed that mutations and multiplications of the α-synuclein gene are responsible for the onset of familial forms of PD. A large body of evidence indicates that α-synuclein pathology at dopaminergic synapses may underlie the onset of neuronal cell dysfunction and degeneration in the PD brain. Thus, since the available therapeutic approaches to cure this disease are still limited, we hypothesized that the analysis of the α-synuclein synaptic proteome/lipidome may represent a tool to identify novel potential therapeutic targets to cure this disorder. We thus performed a critical review of studies describing α-synuclein pathophysiology at synaptic sites in experimental models of PD and in this paper we outline the most relevant findings regarding the specific modulatory effects exerted by α-synuclein in the control of synaptic functions in physiological and pathological conditions. The conclusions of these studies allow to single out novel potential therapeutic targets among the α-synuclein synaptic partners. These targets may be considered for the development of new pharmacological and gene-based strategies to cure PD.
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Affiliation(s)
- Arianna Bellucci
- Division of Pharmacology, Department of Biomedical Sciences and Biotechnology and National Institute of Neuroscience - Italy, School of Medicine, University of Brescia, Brescia, Italy.
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Shukla V, Mishra SK, Pant HC. Oxidative stress in neurodegeneration. Adv Pharmacol Sci 2011; 2011:572634. [PMID: 21941533 PMCID: PMC3177364 DOI: 10.1155/2011/572634] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 06/22/2011] [Indexed: 11/29/2022] Open
Abstract
It has been demonstrated that oxidative stress has a ubiquitous role in neurodegenerative diseases. Major source of oxidative stress due to reactive oxygen species (ROS) is related to mitochondria as an endogenous source. Although there is ample evidence from tissues of patients with neurodegenerative disorders of morphological, biochemical, and molecular abnormalities in mitochondria, it is still not very clear whether the oxidative stress itself contributes to the onset of neurodegeneration or it is part of the neurodegenerative process as secondary manifestation. This paper begins with an overview of how oxidative stress occurs, discussing various oxidants and antioxidants, and role of oxidative stress in diseases in general. It highlights the role of oxidative stress in neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's diseases and amyotrophic lateral sclerosis. The last part of the paper describes the role of oxidative stress causing deregulation of cyclin-dependent kinase 5 (Cdk5) hyperactivity associated with neurodegeneration.
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Affiliation(s)
- Varsha Shukla
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Santosh K. Mishra
- Molecular Genetics Unit, Laboratory of Sensory Biology, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Harish C. Pant
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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50
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Choong CJ, Say YH. Neuroprotection of α-synuclein under acute and chronic rotenone and maneb treatment is abolished by its familial Parkinson's disease mutations A30P, A53T and E46K. Neurotoxicology 2011; 32:857-63. [PMID: 21658409 DOI: 10.1016/j.neuro.2011.05.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 03/31/2011] [Accepted: 05/23/2011] [Indexed: 11/30/2022]
Abstract
α-Synuclein (α-Syn) plays a crucial role in the pathophysiology of Parkinson's disease (PD). α-Syn has been extensively studied in many neuronal cell-based PD models but has yielded mixed results. The objective of this study was to re-evaluate the dual cytotoxic/protective roles of α-Syn in dopaminergic SH-SY5Y cells. Stable SH-SY5Y cells overexpressing wild type or familial α-Syn mutants (A30P, E46K and A53T) were subjected to acute and chronic rotenone and maneb treatment. Compared with untransfected SH-SY5Y cells, wild type α-Syn attenuated rotenone and maneb-induced cell death along with an attenuation of toxin-induced mitochondrial membrane potential changes and Reactive Oxygen Species level, whereas the mutant α-Syn constructs exacerbated environmental toxins-induced cytotoxicity. After chronic treatment, wild type α-Syn but not the mutant variants was found to rescue cells from subsequent acute hydrogen peroxide insult. These results suggest that the fundamental property of wild type α-Syn may be protective, and such property may be lost by its familial PD mutations.
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Affiliation(s)
- Chi-Jing Choong
- Department of Biomedical Science, Faculty of Science, Universiti Tunku Abdul Rahman (UTAR) Perak Campus, 31900 Kampar, Perak, Malaysia
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