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Choza JI, Virani M, Kuhn NC, Adams M, Kochmanski J, Bernstein AI. Parkinson's disease-associated shifts between DNA methylation and DNA hydroxymethylation in human brain in PD-related genes, including PARK19 (DNAJC6) and PTPRN2 (IA-2β). RESEARCH SQUARE 2024:rs.3.rs-4572401. [PMID: 39070644 PMCID: PMC11275970 DOI: 10.21203/rs.3.rs-4572401/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Background The majority of Parkinson's disease (PD) cases are due to a complex interaction between aging, genetics, and environmental factors; epigenetic mechanisms are thought to act as important mediators of these risk factors. While multiple studies to date have explored the role of DNA modifications in PD, few focus on 5-hydroxymethylcytosine (5hmC). Because 5hmC occurs at its highest levels in the brain and is thought to be particularly important in the central nervous system, particularly in the response to neurotoxicants, it is important to explore the potential role of 5hmC in PD. This study expands on our previously published epigenome-wide association study (EWAS) performed on DNA isolated from neuron-enriched nuclei from human postmortem parietal cortex from the Banner Sun Health Research Institute Brain Bank. The study aimed to identify paired changes in 5hmC and 5mC in PD in enriched neuronal nuclei isolated from PD post-mortem parietal cortex and age- and sex-matched controls. We performed oxidative bisulfite (oxBS) conversion and paired it with our previously published bisulfite (BS)-based EWAS on the same samples to identify cytosines with significant shifts between these two related epigenetic marks. Interaction differentially modified cytosines (iDMCs) were identified using our recently published mixed-effects model for co-analyzing βmC and βhmC data. Results We identified 1,030 iDMCs with paired changes in 5mC and 5hmC (FDR < 0.05) that map to 695 genes, including PARK19 (DNAJC6), a familial PD gene, and PTPRN2 (IA-2), which has been previously implicated in PD in both epigenetic and mechanistic studies. The majority of iDMC-containing genes have not previously been implicated in PD and were not identified in our previous BS-based EWAS. Conclusions These data potentially link epigenetic regulation of the PARK19 and PTPRN2 loci in the pathogenesis of idiopathic PD. In addition, iDMC-containing genes have known functions in synaptic formation and function, cell cycle and senescence, neuroinflammation, and epigenetic regulation. These data suggest that there are significant shifts between 5mC and 5hmC associated with PD in genes relevant to PD pathogenesis that are not captured by analyzing BS-based data alone or by analyzing each mark as a distinct dataset.
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Kochmanski J, Virani M, Kuhn NC, Boyd SL, Becker K, Adams M, Bernstein AI. Developmental origins of parkinson's disease risk: perinatal exposure to the organochlorine pesticide dieldrin leads to sex-specific DNA modifications in critical neurodevelopmental pathways in the mouse midbrain. Toxicol Sci 2024:kfae091. [PMID: 38995845 DOI: 10.1093/toxsci/kfae091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024] Open
Abstract
Epidemiological studies show that exposure to the organochlorine pesticide dieldrin is associated with increased risk of Parkinson's disease (PD). Animal studies support a link between developmental dieldrin exposure and increased neuronal susceptibility in the α-synuclein preformed fibril (α-syn PFF) and MPTP models in adult male C57BL/6 mice. In a previous study, we showed that developmental dieldrin exposure was associated with sex-specific changes in DNA modifications within genes related to dopaminergic neuron development and maintenance at 12 weeks of age. Here, we used capture hybridization-sequencing with custom baits to interrogate DNA modifications across the entire genetic loci of the previously identified genes at multiple time points-birth, 6 weeks, 12 weeks, and 36 weeks old. We identified largely sex-specific dieldrin-induced changes in DNA modifications at each time point that annotated to pathways important for neurodevelopment, potentially related to critical steps in early neurodevelopment, dopaminergic neuron differentiation, synaptogenesis, synaptic plasticity, and glial-neuron interactions. Despite large numbers of age-specific DNA modifications, longitudinal analysis identified a small number of DMCs with dieldrin-induced deflection of epigenetic aging. The sex-specificity of these results adds to evidence that sex-specific responses to PD-related exposures may underly sex-specific differences in disease. Overall, these data support the idea that developmental dieldrin exposure leads to changes in epigenetic patterns that persist after the exposure period and disrupt critical neurodevelopmental pathways, thereby impacting risk of late life diseases, including PD.
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Affiliation(s)
- Joseph Kochmanski
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Mahek Virani
- Department of Pharmacology and Toxicology, and Rutgers University, Piscataway, NJ
| | - Nathan C Kuhn
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Sierra L Boyd
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Katelyn Becker
- Genomics Core, Van Andel Research Institute, Grand Rapids, MI
| | - Marie Adams
- Genomics Core, Van Andel Research Institute, Grand Rapids, MI
| | - Alison I Bernstein
- Department of Pharmacology and Toxicology, and, Rutgers University, Piscataway, NJ
- Environmental and Occupational Health Sciences Institute, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
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Bucher ML, Dunn AR, Bradner JM, Egerton KS, Burkett JP, Johnson MA, Miller GW. Synaptic vesicle glycoprotein 2C enhances vesicular storage of dopamine and counters dopaminergic toxicity. Eur J Neurosci 2024; 59:2483-2501. [PMID: 38532289 DOI: 10.1111/ejn.16311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 02/14/2024] [Accepted: 02/22/2024] [Indexed: 03/28/2024]
Abstract
Dopaminergic neurons of the substantia nigra exist in a persistent state of vulnerability resulting from high baseline oxidative stress, high-energy demand, and broad unmyelinated axonal arborisations. Impairments in the storage of dopamine compound this stress because of cytosolic reactions that transform the vital neurotransmitter into an endogenous neurotoxicant, and this toxicity is thought to contribute to the dopamine neuron degeneration that occurs Parkinson's disease. We have previously identified synaptic vesicle glycoprotein 2C (SV2C) as a modifier of vesicular dopamine function, demonstrating that genetic ablation of SV2C in mice results in decreased dopamine content and evoked dopamine release in the striatum. Here, we adapted a previously published in vitro assay utilising false fluorescent neurotransmitter 206 (FFN206) to visualise how SV2C regulates vesicular dopamine dynamics and determined that SV2C promotes the uptake and retention of FFN206 within vesicles. In addition, we present data indicating that SV2C enhances the retention of dopamine in the vesicular compartment with radiolabelled dopamine in vesicles isolated from immortalised cells and from mouse brain. Further, we demonstrate that SV2C enhances the ability of vesicles to store the neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) and that genetic ablation of SV2C results in enhanced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced vulnerability in mice. Together, these findings suggest that SV2C functions to enhance vesicular storage of dopamine and neurotoxicants and helps maintain the integrity of dopaminergic neurons.
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Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- AbbVie CRC, Cambridge, Massachusetts, USA
| | - Kristen Stout Egerton
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- School of Education and Health Sciences, North Central College, Naperville, Illinois, USA
| | - James P Burkett
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Michelle A Johnson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- College of Arts and Sciences, Oberlin College, Oberlin, Ohio, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
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Kochmanski J, Virani M, Kuhn NC, Boyd SL, Becker K, Adams M, Bernstein AI. Developmental origins of Parkinson's disease risk: perinatal exposure to the organochlorine pesticide dieldrin leads to sex-specific DNA modifications in critical neurodevelopmental pathways in the mouse midbrain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.590998. [PMID: 38746441 PMCID: PMC11092502 DOI: 10.1101/2024.04.26.590998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Epidemiological studies show that exposure to the organochlorine pesticide dieldrin is associated with increased risk of Parkinson's disease (PD). Animal studies support a link between developmental dieldrin exposure and increased neuronal susceptibility in the α-synuclein preformed fibril (α-syn PFF) and MPTP models in adult male C57BL/6 mice. In a previous study, we showed that developmental dieldrin exposure was associated with sex-specific changes in DNA modifications within genes related to dopaminergic neuron development and maintenance at 12 weeks of age. Here, we used capture hybridization-sequencing with custom baits to interrogate DNA modifications across the entire genetic loci of the previously identified genes at multiple time points - birth, 6 weeks, 12 weeks, and 36 weeks old. We identified largely sex-specific dieldrin-induced changes in DNA modifications at each time point that annotated to pathways important for neurodevelopment, potentially related to critical steps in early neurodevelopment, dopaminergic neuron differentiation, synaptogenesis, synaptic plasticity, and glial-neuron interactions. Despite large numbers of age-specific DNA modifications, longitudinal analysis identified a small number of DMCs with dieldrin-induced deflection of epigenetic aging. The sex-specificity of these results adds to evidence that sex-specific responses to PD-related exposures may underly sex-specific differences in disease. Overall, these data support the idea that developmental dieldrin exposure leads to changes in epigenetic patterns that persist after the exposure period and disrupt critical neurodevelopmental pathways, thereby impacting risk of late life diseases, including PD.
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Affiliation(s)
- Joseph Kochmanski
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Mahek Virani
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ
| | - Nathan C. Kuhn
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Sierra L. Boyd
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
| | - Katelyn Becker
- Genomics Core, Van Andel Research Institute, Grand Rapids, MI
| | - Marie Adams
- Genomics Core, Van Andel Research Institute, Grand Rapids, MI
| | - Alison I. Bernstein
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ
- Environmental and Occupational Health Sciences Institute, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI
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Rasool A, Manzoor R, Ullah K, Afzal R, Ul-Haq A, Imran H, Kaleem I, Akhtar T, Farrukh A, Hameed S, Bashir S. Oxidative Stress and Dopaminergic Metabolism: A Major PD Pathogenic Mechanism and Basis of Potential Antioxidant Therapies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:852-864. [PMID: 37303175 DOI: 10.2174/1871527322666230609141519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 02/19/2023] [Accepted: 03/14/2023] [Indexed: 06/13/2023]
Abstract
Reactive oxygen species (ROS)-induced oxidative stress triggers the vicious cycle leading to the degeneration of dopaminergic neurons in the nigra pars compacta. ROS produced during the metabolism of dopamine is immediately neutralized by the endogenous antioxidant defense system (EADS) under physiological conditions. Aging decreases the vigilance of EADS and makes the dopaminergic neurons more vulnerable to oxidative stress. As a result, ROS left over by EADS oxidize the dopamine-derived catechols and produces a number of reactive dopamine quinones, which are precursors to endogenous neurotoxins. In addition, ROS causes lipid peroxidation, uncoupling of the electron transport chain, and DNA damage, which lead to mitochondrial dysfunction, lysosomal dysfunction, and synaptic dysfunction. The mutations in genes such as DNAJC6, SYNJ1, SH3GL2, LRRK2, PRKN, and VPS35 caused by ROS have been associated with synaptic dysfunction and the pathogenesis of Parkinson's disease (PD). The available drugs that are used against PD can only delay the progression of the disease, but they produce various side effects. Through their antioxidant activity, flavonoids can substantiate the EADS of dopaminergic neurons and disrupt the vicious cycle incepted by oxidative stress. In this review, we show how the oxidative metabolism of dopamine generates ROS and dopamine-quinones, which then exert unrestrained OS, causing mutations in several genes involved in the proper functioning of mitochondrion, synapse, and lysosome. Besides, we also present some examples of approved drugs used for the treatment of PD, therapies in the clinical trial phase, and an update on the flavonoids that have been tested to boost the EADS of dopaminergic neurons.
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Affiliation(s)
- Aamir Rasool
- Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, PR China
- Institute of Biochemistry, University of Balochistan, Quetta 87300, Pakistan
| | - Robina Manzoor
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
- Faculty of Marine Sciences, Lasbella University of Agriculture Water and Marine Sciences, Uthal 90050, Pakistan
| | - Kaleem Ullah
- Department of Microbiology, University of Balochistan, Quetta 87300, Pakistan
| | - Ramsha Afzal
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Asad Ul-Haq
- Division of Rheumatology, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Republic of Korea
| | - Hadia Imran
- Department of Biosciences, COMSATS University Islamabad, Pakistan
| | - Imdad Kaleem
- Department of Biosciences, COMSATS University Islamabad, Pakistan
| | | | - Anum Farrukh
- Department of General Medicine, Fauji Foundation Hospital (FFH), Rawalpindi, Pakistan
| | - Sahir Hameed
- National Institute for Genomics and Advanced Biotechnology (N.I.G.A.B.) National Agriculture Research Centre Islamabad, Pakistan
| | - Shahid Bashir
- Neurosciences Center, King Fahad Specialist Hospital Dammam, P.O. Box 15215, Dammam 31444, Saudi Arabia
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Park JS, Ahmad R, Choe K, Kang MH, Park TJ, Kim MO. Immunization Effects of a Novel α-Synuclein-Based Peptide Epitope Vaccine in Parkinson's Disease-Associated Pathology. Vaccines (Basel) 2023; 11:1820. [PMID: 38140224 PMCID: PMC10748214 DOI: 10.3390/vaccines11121820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 12/24/2023] Open
Abstract
Parkinson's disease (PD) is a chronic neurodegenerative disease that affects the central nervous system, specifically the motor system. It is mainly caused by the loss of dopamine due to the accumulation of α-synuclein (α-syn) protein in the striatum and substantia nigra pars compacta (SNpc). Previous studies have reported that immunization may be a potential preventive strategy for neurodegenerative diseases such as Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). Therefore, the aim of the study was to design an α-syn specific epitope vaccine and investigate its effect in PD-related pathophysiology using an α-syn-induced mouse model. We used an in silico model to identify and design a non-toxic α-syn-based peptide epitope vaccine and, to overcome poor immunogenicity, the vaccine was coupled with immunogenic carrier proteins, i.e., ovalbumin (OVA) and keyhole limpet haemocyanin (KLH). Our results showed that vaccinated PD mouse models, especially with vaccines with carrier proteins, improved in motor functions compared with the non-vaccinated PD model. Additionally, the vaccinated groups showed increased immunoglobulin G (IgG) levels in the spleen and plasma as well as decreased interleukin-10 (IL-10) levels in the plasma. Furthermore, vaccinated groups, especially OVA and KLH groups, showed decrease in α-syn levels and increased dopamine-related markers, i.e., tyrosine hydroxylase (TH), vesicle monoamine transporter 2 (VMAT2), and dopamine transporter (DAT), and autophagy activities in the striatum and SNpc. Lastly, our data showed decreased neuroinflammation by reducing the activation of microglia and astrocytes and pro-inflammatory cytokines in the immunized groups, especially with OVA and KLH carrier proteins. Overall, these results suggest that vaccination, especially with immunogenic carrier proteins, is effective in reducing the accumulation of α-syn aggregates in the brain and ameliorate PD-related pathophysiology. Hence, further development of this approach might have a potential role in preventing the development of PD.
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Affiliation(s)
- Jun Sung Park
- Division of Life Sciences and Applied Life Science (BK 21 Four), College of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; (J.S.P.); (R.A.); (M.H.K.)
| | - Riaz Ahmad
- Division of Life Sciences and Applied Life Science (BK 21 Four), College of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; (J.S.P.); (R.A.); (M.H.K.)
| | - Kyonghwan Choe
- Division of Life Sciences and Applied Life Science (BK 21 Four), College of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; (J.S.P.); (R.A.); (M.H.K.)
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Min Hwa Kang
- Division of Life Sciences and Applied Life Science (BK 21 Four), College of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; (J.S.P.); (R.A.); (M.H.K.)
| | - Tae Ju Park
- Haemato-Oncology/Systems Medicine Group, Paul O’Gorman Leukaemia Research Centre, Institute of Cancer Sciences, College of Medical, Veterinary & Life Sciences (MVLS), University of Glasgow, Glasgow G12 0ZD, UK;
| | - Myeong Ok Kim
- Division of Life Sciences and Applied Life Science (BK 21 Four), College of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea; (J.S.P.); (R.A.); (M.H.K.)
- Alz-Dementia Korea Co., Jinju 52828, Republic of Korea
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Boyd SL, Kuhn NC, Patterson JR, Stoll AC, Zimmerman SA, Kolanowski MR, Neubecker JJ, Luk KC, Ramsson ES, Sortwell CE, Bernstein AI. Developmental exposure to the Parkinson's disease-associated organochlorine pesticide dieldrin alters dopamine neurotransmission in α-synuclein pre-formed fibril (PFF)-injected mice. Toxicol Sci 2023; 196:99-111. [PMID: 37607008 PMCID: PMC10613968 DOI: 10.1093/toxsci/kfad086] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023] Open
Abstract
Parkinson's disease (PD) is the fastest-growing neurological disease worldwide, with increases outpacing aging and occurring most rapidly in recently industrialized areas, suggesting a role of environmental factors. Epidemiological, post-mortem, and mechanistic studies suggest that persistent organic pollutants, including the organochlorine pesticide dieldrin, increase PD risk. In mice, developmental dieldrin exposure causes male-specific exacerbation of neuronal susceptibility to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and synucleinopathy. Specifically, in the α-synuclein (α-syn) pre-formed fibril (PFF) model, exposure leads to increased deficits in striatal dopamine (DA) turnover and motor deficits on the challenging beam. Here, we hypothesized that alterations in DA handling contribute to the observed changes and assessed vesicular monoamine transporter 2 (VMAT2) function and DA release in this dieldrin/PFF 2-hit model. Female C57BL/6 mice were exposed to 0.3 mg/kg dieldrin or vehicle every 3 days by feeding, starting at 8 weeks of age and continuing throughout breeding, gestation, and lactation. Male offspring from independent litters underwent unilateral, intrastriatal injections of α-syn PFFs at 12 weeks of age, and vesicular 3H-DA uptake assays and fast-scan cyclic voltammetry were performed 4 months post-PFF injection. Dieldrin-induced an increase in DA release in striatal slices in PFF-injected animals, but no change in VMAT2 activity. These results suggest that developmental dieldrin exposure increases a compensatory response to synucleinopathy-triggered striatal DA loss. These findings are consistent with silent neurotoxicity, where developmental exposure to dieldrin primes the nigrostriatal striatal system to have an exacerbated response to synucleinopathy in the absence of observable changes in typical markers of nigrostriatal dysfunction and degeneration.
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Affiliation(s)
- Sierra L Boyd
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Nathan C Kuhn
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Joseph R Patterson
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Anna C Stoll
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Sydney A Zimmerman
- Biomedical Sciences Department, Grand Valley State University, Allendale, MI, USA
| | - Mason R Kolanowski
- Biomedical Sciences Department, Grand Valley State University, Allendale, MI, USA
| | - Joseph J Neubecker
- Biomedical Sciences Department, Grand Valley State University, Allendale, MI, USA
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania, Philadelphia, PA, USA
| | - Eric S Ramsson
- Biomedical Sciences Department, Grand Valley State University, Allendale, MI, USA
| | - Caryl E Sortwell
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Alison I Bernstein
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
- Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ, USA
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ, USA
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Khashab R, Gutman-Sharabi N, Shabtai Z, Landau R, Halperin R, Fay-Karmon T, Leibowitz A, Sharabi Y. Dihydroxyphenylacetaldehyde Lowering Treatment Improves Locomotor and Neurochemical Abnormalities in the Rat Rotenone Model: Relevance to the Catecholaldehyde Hypothesis for the Pathogenesis of Parkinson's Disease. Int J Mol Sci 2023; 24:12522. [PMID: 37569897 PMCID: PMC10419703 DOI: 10.3390/ijms241512522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/24/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
The catecholaldehyde hypothesis for the pathogenesis of Parkinson's disease centers on accumulation of 3,4-dihydroxyphenylacetaldehyde (DOPAL) in dopaminergic neurons. To test the hypothesis, it is necessary to reduce DOPAL and assess if this improves locomotor abnormalities. Systemic administration of rotenone to rats reproduces the motor and central neurochemical abnormalities characterizing Parkinson's disease. In this study, we used the monoamine oxidase inhibitor (MAOI) deprenyl to decrease DOPAL production, with or without the antioxidant N-acetylcysteine (NAC). Adult rats received subcutaneous vehicle, rotenone (2 mg/kg/day via a minipump), or rotenone with deprenyl (5 mg/kg/day i.p.) with or without oral NAC (1 mg/kg/day) for 28 days. Motor function tests included measures of open field activity and rearing. Striatal tissue was assayed for contents of dopamine, DOPAL, and other catechols. Compared to vehicle, rotenone reduced locomotor activity (distance, velocity and rearing); increased tissue DOPAL; and decreased dopamine concentrations and inhibited vesicular sequestration of cytoplasmic dopamine and enzymatic breakdown of cytoplasmic DOPAL by aldehyde dehydrogenase (ALDH), as indicated by DA/DOPAL and DOPAC/DOPAL ratios. The addition of deprenyl to rotenone improved all the locomotor indices, increased dopamine and decreased DOPAL contents, and corrected the rotenone-induced vesicular uptake and ALDH abnormalities. The beneficial effects were augmented when NAC was added to deprenyl. Rotenone evokes locomotor and striatal neurochemical abnormalities found in Parkinson's disease, including DOPAL buildup. Administration of an MAOI attenuates these abnormalities, and NAC augments the beneficial effects. The results indicate a pathogenic role of DOPAL in the rotenone model and suggest that treatment with MAOI+NAC might be beneficial for Parkinson's disease treatment.
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Affiliation(s)
- Rawan Khashab
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Naama Gutman-Sharabi
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Zehava Shabtai
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Regev Landau
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Reut Halperin
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tsviya Fay-Karmon
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Avshalom Leibowitz
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yehonatan Sharabi
- Hypertension Unit, Chaim Sheba Medical Center, Tel-HaShomer, Ramat Gan 5265601, Israel; (R.K.); (N.G.-S.); (Z.S.); (R.L.); (R.H.); (T.F.-K.); (A.L.)
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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9
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Bucher ML, Dunn AR, Bradner JM, Egerton KS, Burkett JP, Johnson MA, Miller GW. Synaptic vesicle glycoprotein 2C enhances vesicular storage of dopamine and counters dopaminergic toxicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546143. [PMID: 37425736 PMCID: PMC10326994 DOI: 10.1101/2023.06.26.546143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Dopaminergic neurons of the substantia nigra exist in a persistent state of vulnerability resulting from high baseline oxidative stress, high energy demand, and broad unmyelinated axonal arborizations. Impairments in the storage of dopamine compound this stress due to cytosolic reactions that transform the vital neurotransmitter into an endogenous neurotoxicant, and this toxicity is thought to contribute to the dopamine neuron degeneration that occurs Parkinson's disease. We have previously identified synaptic vesicle glycoprotein 2C (SV2C) as a modifier of vesicular dopamine function, demonstrating that genetic ablation of SV2C in mice results in decreased dopamine content and evoked dopamine release in the striatum. Here, we adapted a previously published in vitro assay utilizing false fluorescent neurotransmitter 206 (FFN206) to visualize how SV2C regulates vesicular dopamine dynamics and determined that SV2C promotes the uptake and retention of FFN206 within vesicles. In addition, we present data indicating that SV2C enhances the retention of dopamine in the vesicular compartment with radiolabeled dopamine in vesicles isolated from immortalized cells and from mouse brain. Further, we demonstrate that SV2C enhances the ability of vesicles to store the neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) and that genetic ablation of SV2C results in enhanced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced vulnerability in mice. Together, these findings suggest that SV2C functions to enhance vesicular storage of dopamine and neurotoxicants, and helps maintain the integrity of dopaminergic neurons.
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Affiliation(s)
- Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Kristen Stout Egerton
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - James P Burkett
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Michelle A Johnson
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10031, USA
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10
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Campos ACP, Pople C, Silk E, Surendrakumar S, Rabelo TK, Meng Y, Gouveia FV, Lipsman N, Giacobbe P, Hamani C. Neurochemical mechanisms of deep brain stimulation for depression in animal models. Eur Neuropsychopharmacol 2023; 68:11-26. [PMID: 36640729 DOI: 10.1016/j.euroneuro.2022.12.003] [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] [Received: 10/19/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/13/2023]
Abstract
Deep brain stimulation (DBS) has emerged as a neuromodulation therapy for treatment-resistant depression, but its actual efficacy and mechanisms of action are still unclear. Changes in neurochemical transmission are important mechanisms of antidepressant therapies. Here, we review the preclinical DBS literature reporting behavioural and neurochemical data associated with its antidepressant-like effects. The most commonly studied target in preclinical models was the ventromedial prefrontal cortex (vmPFC). In rodents, DBS delivered to this target induced serotonin (5-HT) release and increased 5-HT1B receptor expression. The antidepressant-like effects of vmPFC DBS seemed to be independent of the serotonin transporter and potentially mediated by the direct modulation of prefrontal projections to the raphe. Adenosinergic and glutamatergic transmission might have also play a role. Medial forebrain bundle (MFB) DBS increased dopamine levels and reduced D2 receptor expression, whereas nucleus accumbens (NAcc), and lateral habenula (LHb) stimulation increased catecholamine levels in different brain regions. In rodents, subthalamic nucleus (STN) DBS induced robust depression-like responses associated with a reduction in serotonergic transmission, as revealed by a decrease in serotonin release. Some of these effects seemed to be mediated by 5HT1A receptors. In conclusion, the antidepressant-like effects of DBS in preclinical models have been well documented in multiple targets. Though variable mechanisms have been proposed, DBS-induced acute and long-term changes in neurochemical substrates seem to play an important role in the antidepressant-like effects of this therapy.
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Affiliation(s)
- Ana Carolina P Campos
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Christopher Pople
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Esther Silk
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Shanan Surendrakumar
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Thallita K Rabelo
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Ying Meng
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Flavia Venetucci Gouveia
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Nir Lipsman
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Hurvitz Brain Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Division of Neurosurgery, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON M4N 3M5, Canada
| | - Peter Giacobbe
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Hurvitz Brain Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Neuropsychiatry Program, Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Clement Hamani
- Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Hurvitz Brain Sciences Centre, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada; Division of Neurosurgery, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON M4N 3M5, Canada.
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11
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Xu Y, Li C, Chen T, Li X, Wu X, Zhang Q, Zhao L. Quantitative Analysis of the Multicomponent and Spectrum-Effect Correlation of the Antispasmodic Activity of Shaoyao-Gancao Decoction. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2022; 2022:2279404. [PMID: 36507107 PMCID: PMC9734003 DOI: 10.1155/2022/2279404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 11/16/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Shaoyao-Gancao Decoction (SGD) is a well-known classic traditional Chinese medicine (TCM) with antispasmodic, anti-inflammatory, and analgesic effects. This preparation has been widely used to treat spasticity diseases in the clinic. To date, the material basis of SGD remains unclear, and the spectrum-effect correlation of its antispasmodic activity has not been reported yet. In this study, high-performance liquid chromatography (HPLC) was used to establish the fingerprint and determine the multiple components of SGD. The common peaks of fingerprints were evaluated by the similarity with the chromatographic fingerprints of the TCM. Meanwhile, the multiple components were quantified and analysed using the heatmap and box size analysis. Furthermore, data on the antispasmodic effect were extracted through in vitro smooth muscle contraction assay. Grey relational analysis combined with partial least square regression was used to study the spectrum-effect correlation of SGD. Finally, the potential antispasmolytic components were validated using an isolated tissue experiment. The HPLC fingerprint was established, and 20 common peaks were identified. The similarities of 15 batches of SGD were all above 0.965. The HPLC method for simultaneous determination of the multiple components was accurate and reliable. The contents of albiflorin, paeoniflorin, liquiritin, and glycyrrhizic acid were higher than the other components in SGD. The heatmap and box size also showed that X3 (albiflorin), X4 (paeoniflorin), X5 (liquiritin), X11 (liquirtigenin), and X16 (glycyrrhizic acid) could be used as quality indicators in the further establishment of quality standards. The spectrum-effect correlation results indicated that X4, X11, and X16 were highly correlated with antispasmolytic activity. Verification tests showed that paeoniflorin (11.7-29.25 μg/mL) and liquirtigenin (17.19-28.65 μg/mL) could significantly reduce the maximum contractile (P < 0.01). These compounds exerted concentration-dependent spasmolytic effects with the inhibitory response for acetylcholine (Ach)-evoked contraction. Thus, SGD had a significant antispasmodic effect, which resulted from the synergistic activity of its multiple components. These findings can be used for the pharmacodynamics study of SGD and are of great significance for the determination of quality markers and quality control.
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Affiliation(s)
- Yanli Xu
- Gansu University of Chinese Medicine, Lanzhou 730000, China
- Lanzhou Institute for Food and Drug Control, Lanzhou 730000, China
| | - Chenxi Li
- Lanzhou Institute for Food and Drug Control, Lanzhou 730000, China
| | - Ting Chen
- Lanzhou Institute for Food and Drug Control, Lanzhou 730000, China
| | - Xiaochun Li
- Lanzhou Institute for Food and Drug Control, Lanzhou 730000, China
| | - Xiaoyu Wu
- Gansu University of Chinese Medicine, Lanzhou 730000, China
- Northwest Collaborative Innovation Center for Traditional Chinese Medicine Co-Constructed By Gansu Province & MOE of PRC, Lanzhou 730000, China
- Key Laboratory of Chemistry and Quality of TCM of the College of Gansu Province, Lanzhou 730000, China
- Gansu Province Engineering Laboratory for TCM Standardization Technology and Popularization, Lanzhou 730000, China
| | - Qili Zhang
- Gansu University of Chinese Medicine, Lanzhou 730000, China
- Northwest Collaborative Innovation Center for Traditional Chinese Medicine Co-Constructed By Gansu Province & MOE of PRC, Lanzhou 730000, China
| | - Lei Zhao
- Gansu University of Chinese Medicine, Lanzhou 730000, China
- Lanzhou Institute for Food and Drug Control, Lanzhou 730000, China
- Northwest Collaborative Innovation Center for Traditional Chinese Medicine Co-Constructed By Gansu Province & MOE of PRC, Lanzhou 730000, China
- Key Laboratory of Chemistry and Quality of TCM of the College of Gansu Province, Lanzhou 730000, China
- Gansu Province Engineering Laboratory for TCM Standardization Technology and Popularization, Lanzhou 730000, China
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12
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Expression Analysis of Genes Involved in Transport Processes in Mice with MPTP-Induced Model of Parkinson’s Disease. Life (Basel) 2022; 12:life12050751. [PMID: 35629417 PMCID: PMC9146539 DOI: 10.3390/life12050751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
Processes of intracellular and extracellular transport play one of the most important roles in the functioning of cells. Changes to transport mechanisms in a neuron can lead to the disruption of many cellular processes and even to cell death. It was shown that disruption of the processes of vesicular, axonal, and synaptic transport can lead to a number of diseases of the central nervous system, including Parkinson’s disease (PD). Here, we studied changes in the expression of genes whose protein products are involved in the transport processes (Snca, Drd2, Rab5a, Anxa2, and Nsf) in the brain tissues and peripheral blood of mice with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced models of PD. We detected changes in the expressions of Drd2, Anxa2, and Nsf at the earliest modeling stages. Additionally, we have identified conspicuous changes in the expression level of Anxa2 in the striatum and substantia nigra of mice with MPTP-induced models of PD in its early stages. These data clearly suggest the involvement of protein products in these genes in the earliest stages of the pathogenesis of PD.
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13
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Srinivasan E, Chandrasekhar G, Chandrasekar P, Anbarasu K, Vickram AS, Karunakaran R, Rajasekaran R, Srikumar PS. Alpha-Synuclein Aggregation in Parkinson's Disease. Front Med (Lausanne) 2021; 8:736978. [PMID: 34733860 PMCID: PMC8558257 DOI: 10.3389/fmed.2021.736978] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
Parkinson's disease (PD), a neurodegenerative disorder characterized by distinct aging-independent loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) region urging toward neuronal loss. Over the decade, various key findings from clinical perspective to molecular pathogenesis have aided in understanding the genetics with assorted genes related with PD. Subsequently, several pathways have been incriminated in the pathogenesis of PD, involving mitochondrial dysfunction, protein aggregation, and misfolding. On the other hand, the sporadic form of PD cases is found with no genetic linkage, which still remain an unanswered question? The exertion in ascertaining vulnerability factors in PD considering the genetic factors are to be further dissevered in the forthcoming decades with advancement in research studies. One of the major proponents behind the prognosis of PD is the pathogenic transmutation of aberrant alpha-synuclein protein into amyloid fibrillar structures, which actuates neurodegeneration. Alpha-synuclein, transcribed by SNCA gene is a neuroprotein found predominantly in brain. It is implicated in the modulation of synaptic vesicle transport and eventual release of neurotransmitters. Due to genetic mutations and other elusive factors, the alpha-synuclein misfolds into its amyloid form. Therefore, this review aims in briefing the molecular understanding of the alpha-synuclein associated with PD.
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Affiliation(s)
- E Srinivasan
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India.,Department of Bioinformatics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India
| | - G Chandrasekhar
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India
| | - P Chandrasekar
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India
| | - K Anbarasu
- Department of Bioinformatics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India
| | - A S Vickram
- Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India
| | - Rohini Karunakaran
- Unit of Biochemistry, Faculty of Medicine, AIMST University, Bedong, Malaysia
| | - R Rajasekaran
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India
| | - P S Srikumar
- Unit of Psychiatry, Faculty of Medicine, AIMST University, Bedong, Malaysia
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14
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Carmichael K, Sullivan B, Lopez E, Sun L, Cai H. Diverse midbrain dopaminergic neuron subtypes and implications for complex clinical symptoms of Parkinson's disease. AGEING AND NEURODEGENERATIVE DISEASES 2021; 1. [PMID: 34532720 PMCID: PMC8442626 DOI: 10.20517/and.2021.07] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Parkinson’s disease (PD), the most common degenerative movement disorder, is clinically manifested with various motor and non-motor symptoms. Degeneration of midbrain substantia nigra pas compacta (SNc) dopaminergic neurons (DANs) is generally attributed to the motor syndrome. The underlying neuronal mechanisms of non-motor syndrome are largely unexplored. Besides SNc, midbrain ventral tegmental area (VTA) DANs also produce and release dopamine and modulate movement, reward, motivation, and memory. Degeneration of VTA DANs also occurs in postmortem brains of PD patients, implying an involvement of VTA DANs in PD-associated non-motor symptoms. However, it remains to be established that there is a distinct segregation of different SNc and VTA DAN subtypes in regulating different motor and non-motor functions, and that different DAN subpopulations are differentially affected by normal ageing or PD. Traditionally, the distinction among different DAN subtypes was mainly based on the location of cell bodies and axon terminals. With the recent advance of single cell RNA sequencing technology, DANs can be readily classified based on unique gene expression profiles. A combination of specific anatomic and molecular markers shows great promise to facilitate the identification of DAN subpopulations corresponding to different behavior modules under normal and disease conditions. In this review, we first summarize the recent progress in characterizing genetically, anatomically, and functionally diverse midbrain DAN subtypes. Then, we provide perspectives on how the preclinical research on the connectivity and functionality of DAN subpopulations improves our current understanding of cell-type and circuit specific mechanisms of the disease, which could be critically informative for designing new mechanistic treatments.
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Affiliation(s)
- Kathleen Carmichael
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.,The Graduate Partnership Program of NIH and Brown University, National Institutes of Health, Bethesda, MD 20892, USA
| | - Breanna Sullivan
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elena Lopez
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lixin Sun
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Huaibin Cai
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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15
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Black CA, Bucher ML, Bradner JM, Jonas L, Igarza K, Miller GW. Assessing Vesicular Monoamine Transport and Toxicity Using Fluorescent False Neurotransmitters. Chem Res Toxicol 2020; 34:1256-1264. [PMID: 33378168 DOI: 10.1021/acs.chemrestox.0c00380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Impairments in the vesicular packaging of dopamine result in an accumulation of dopamine in the cytosol. Cytosolic dopamine is vulnerable to two metabolic processes-enzymatic catabolism and enzymatic- or auto-oxidation-that form toxic metabolites and generate reactive oxygen species. Alterations in the expression or activity of the vesicular monoamine transporter 2 (VMAT2), which transports monoamines such as dopamine from the cytosol into the synaptic vesicle, result in dysregulated dopamine packaging. Here, we developed a series of assays using the fluorescent false neurotransmitter 206 (FFN206) to visualize VMAT2-mediated vesicular packaging at baseline and following pharmacological and toxicological manipulations. As a proof of principle, we observed a significant reduction in vesicular FFN206 packaging after treatment with the VMAT2 inhibitors reserpine (IC50: 73.1 nM), tetrabenazine (IC50: 30.4 nM), methamphetamine (IC50: 2.4 μM), and methylphenidate (IC50: 94.3 μM). We then applied the assay to investigate the consequences on vesicular packaging by environmental toxicants including the pesticides paraquat, rotenone, and chlorpyrifos, as well as the halogenated compounds unichlor, perfluorooctanesulfonic acid, Paroil, Aroclor 1260, and hexabromocyclododecane. Several of the environmental toxicants showed minor impairment of the vesicular FFN206 loading, suggesting that the toxicants are weak VMAT2 inhibitors at the concentrations tested. The assay presented here can be applied to investigate the effect of additional pharmacological compounds and environmental toxicants on vesicular function, which will provide insight into how exposures to such factors are involved in the pathogenesis of monoaminergic diseases such as Parkinson's disease, and the assay can be used to identify pharmacological agents that influence VMAT2 activity.
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Affiliation(s)
- Carlie A Black
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Meghan L Bucher
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
| | - Joshua M Bradner
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
| | - Lauren Jonas
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Kenny Igarza
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States
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16
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Gezer AO, Kochmanski J, VanOeveren SE, Cole-Strauss A, Kemp CJ, Patterson JR, Miller KM, Kuhn NC, Herman DE, McIntire A, Lipton JW, Luk KC, Fleming SM, Sortwell CE, Bernstein AI. Developmental exposure to the organochlorine pesticide dieldrin causes male-specific exacerbation of α-synuclein-preformed fibril-induced toxicity and motor deficits. Neurobiol Dis 2020; 141:104947. [PMID: 32422283 PMCID: PMC7343230 DOI: 10.1016/j.nbd.2020.104947] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/22/2020] [Accepted: 05/13/2020] [Indexed: 12/21/2022] Open
Abstract
Human and animal studies have shown that exposure to the organochlorine pesticide dieldrin is associated with increased risk of Parkinson's disease (PD). Previous work showed that developmental dieldrin exposure increased neuronal susceptibility to MPTP toxicity in male C57BL/6 mice, possibly via changes in dopamine (DA) packaging and turnover. However, the relevance of the MPTP model to PD pathophysiology has been questioned. We therefore studied dieldrin-induced neurotoxicity in the α-synuclein (α-syn)-preformed fibril (PFF) model, which better reflects the α-syn pathology and toxicity observed in PD pathogenesis. Specifically, we used a "two-hit" model to determine whether developmental dieldrin exposure increases susceptibility to α-syn PFF-induced synucleinopathy. Dams were fed either dieldrin (0.3 mg/kg, every 3-4 days) or vehicle corn oil starting 1 month prior to breeding and continuing through weaning of pups at postnatal day 22. At 12 weeks of age, male and female offspring received intrastriatal α-syn PFF or control saline injections. Consistent with the male-specific increased susceptibility to MPTP, our results demonstrate that developmental dieldrin exposure exacerbates PFF-induced toxicity in male mice only. Specifically, in male offspring, dieldrin exacerbated PFF-induced motor deficits on the challenging beam and increased DA turnover in the striatum 6 months after PFF injection. However, male offspring showed neither exacerbation of phosphorylated α-syn aggregation (pSyn) in the substantia nigra (SN) at 1 or 2 months post-PFF injection, nor exacerbation of PFF-induced TH and NeuN loss in the SN 6 months post-PFF injection. Collectively, these data indicate that developmental dieldrin exposure produces a male-specific exacerbation of synucleinopathy-induced behavioral and biochemical deficits. This sex-specific result is consistent with both previous work in the MPTP model, our previously reported sex-specific effects of this exposure paradigm on the male and female epigenome, and the higher prevalence and more severe course of PD in males. The novel two-hit environmental toxicant/PFF exposure paradigm established in this project can be used to explore the mechanisms by which other PD-related exposures alter neuronal vulnerability to synucleinopathy in sporadic PD.
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Affiliation(s)
- Aysegul O Gezer
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America; Cell and Molecular Biology Graduate Program, College of Natural Sciences, Michigan State University, East Lansing, MI, United States of America; College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States of America
| | - Joseph Kochmanski
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Sarah E VanOeveren
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Allyson Cole-Strauss
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Christopher J Kemp
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Joseph R Patterson
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Kathryn M Miller
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Nathan C Kuhn
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America
| | - Danielle E Herman
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH, United States of America
| | - Alyssa McIntire
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH, United States of America
| | - Jack W Lipton
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America; Mercy Health St. Mary's, Grand Rapids, MI, United States of America
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Sheila M Fleming
- Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH, United States of America
| | - Caryl E Sortwell
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America; Mercy Health St. Mary's, Grand Rapids, MI, United States of America
| | - Alison I Bernstein
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States of America; Mercy Health St. Mary's, Grand Rapids, MI, United States of America.
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17
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Ng J, Cortès‐Saladelafont E, Abela L, Termsarasab P, Mankad K, Sudhakar S, Gorman KM, Heales SJ, Pope S, Biassoni L, Csányi B, Cain J, Rakshi K, Coutts H, Jayawant S, Jefferson R, Hughes D, García‐Cazorla À, Grozeva D, Raymond FL, Pérez‐Dueñas B, De Goede C, Pearson TS, Meyer E, Kurian MA. DNAJC6 Mutations Disrupt Dopamine Homeostasis in Juvenile Parkinsonism-Dystonia. Mov Disord 2020; 35:1357-1368. [PMID: 32472658 PMCID: PMC8425408 DOI: 10.1002/mds.28063] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/15/2020] [Accepted: 03/03/2020] [Indexed: 12/24/2022] Open
Abstract
Background Juvenile forms of parkinsonism are rare conditions with onset of bradykinesia, tremor and rigidity before the age of 21 years. These atypical presentations commonly have a genetic aetiology, highlighting important insights into underlying pathophysiology. Genetic defects may affect key proteins of the endocytic pathway and clathrin‐mediated endocytosis (CME), as in DNAJC6‐related juvenile parkinsonism. Objective To report on a new patient cohort with juvenile‐onset DNAJC6 parkinsonism‐dystonia and determine the functional consequences on auxilin and dopamine homeostasis. Methods Twenty‐five children with juvenile parkinsonism were identified from a research cohort of patients with undiagnosed pediatric movement disorders. Molecular genetic investigations included autozygosity mapping studies and whole‐exome sequencing. Patient fibroblasts and CSF were analyzed for auxilin, cyclin G–associated kinase and synaptic proteins. Results We identified 6 patients harboring previously unreported, homozygous nonsense DNAJC6 mutations. All presented with neurodevelopmental delay in infancy, progressive parkinsonism, and neurological regression in childhood. 123I‐FP‐CIT SPECT (DaTScan) was performed in 3 patients and demonstrated reduced or absent tracer uptake in the basal ganglia. CSF neurotransmitter analysis revealed an isolated reduction of homovanillic acid. Auxilin levels were significantly reduced in both patient fibroblasts and CSF. Cyclin G–associated kinase levels in CSF were significantly increased, whereas a number of presynaptic dopaminergic proteins were reduced. Conclusions DNAJC6 is an emerging cause of recessive juvenile parkinsonism‐dystonia. DNAJC6 encodes the cochaperone protein auxilin, involved in CME of synaptic vesicles. The observed dopamine dyshomeostasis in patients is likely to be multifactorial, secondary to auxilin deficiency and/or neurodegeneration. Increased patient CSF cyclin G–associated kinase, in tandem with reduced auxilin levels, suggests a possible compensatory role of cyclin G–associated kinase, as observed in the auxilin knockout mouse. DNAJC6 parkinsonism‐dystonia should be considered as a differential diagnosis for pediatric neurotransmitter disorders associated with low homovanillic acid levels. Future research in elucidating disease pathogenesis will aid the development of better treatments for this pharmacoresistant disorder. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Joanne Ng
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
- Gene Transfer Technology GroupUCL Institute for Women's HealthLondonUnited Kingdom
| | - Elisenda Cortès‐Saladelafont
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Lucia Abela
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Pichet Termsarasab
- Department of NeurologyIcahn School of Medicine at Mount SinaiNew YorkUSA
- Division of Neurology, Department of Medicine, Faculty of Medicine Ramathibodi HospitalMahidol UniversityBangkokThailand
| | - Kshitij Mankad
- Department of RadiologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUnited Kingdom
| | - Sniya Sudhakar
- Department of RadiologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUnited Kingdom
| | - Kathleen M. Gorman
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
- Department of NeurologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUnited Kingdom
| | - Simon J.R. Heales
- Neurometabolic UnitNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Simon Pope
- Neurometabolic UnitNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Lorenzo Biassoni
- Department of RadiologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUnited Kingdom
| | - Barbara Csányi
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - John Cain
- Department of Nuclear Medicine and ImagingLancashire Teaching Hospitals, NHS Foundation TrustPrestonUnited Kingdom
| | - Karl Rakshi
- Department of PaediatricsEast Lancashire Hospital NHS TrustLancashireUnited Kingdom
| | - Helen Coutts
- Department of PaediatricsEast Lancashire Hospital NHS TrustLancashireUnited Kingdom
| | - Sandeep Jayawant
- Department of Paediatric NeurologyJohn Radcliffe Hospital, Oxford University, NHS Foundation TrustLondonUnited Kingdom
| | - Rosalind Jefferson
- Department of PaediatricsRoyal Berkshire Hospital, NHS Foundation TrustReadingUnited Kingdom
| | - Deborah Hughes
- Molecular Neuroscience and Reta Lila Weston LaboratoriesInstitute of NeurologyQueen SquareLondonUnited Kingdom
| | - Àngels García‐Cazorla
- Department of NeurologyNeurometabolic Unit and CIBERER Hospital Sant Joan de Déu, Esplugues de LlobregatBarcelonaSpain
| | - Detelina Grozeva
- Medical GeneticsCambridge Institute for Medical Research, University of CambridgeCambridgeUnited Kingdom
- UK10K Project, Wellcome Trust Sanger InstituteHinxtonCambridgeUnited Kingdom
| | - F. Lucy Raymond
- Medical GeneticsCambridge Institute for Medical Research, University of CambridgeCambridgeUnited Kingdom
- UK10K Project, Wellcome Trust Sanger InstituteHinxtonCambridgeUnited Kingdom
| | - Belén Pérez‐Dueñas
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
- Hospital Vall d'Hebron, Institut de Recerca (VHIR)BarcelonaSpain
| | - Christian De Goede
- Department of Paediatric NeurologyRoyal Preston Hospital, Lancashire Teaching Hospitals, NHS Foundation TrustLondonUnited Kingdom
| | - Toni S. Pearson
- Department of NeurologyIcahn School of Medicine at Mount SinaiNew YorkUSA
- Department of NeurologyWashington University School of MedicineSt. LouisMissouriUSA
| | - Esther Meyer
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Manju A. Kurian
- Molecular Neurosciences, Developmental Neurosciences ProgrammeUCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
- Department of NeurologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUnited Kingdom
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Stout KA, Dunn AR, Hoffman C, Miller GW. The Synaptic Vesicle Glycoprotein 2: Structure, Function, and Disease Relevance. ACS Chem Neurosci 2019; 10:3927-3938. [PMID: 31394034 DOI: 10.1021/acschemneuro.9b00351] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The synaptic vesicle glycoprotein 2 (SV2) family is comprised of three paralogues: SV2A, SV2B, and SV2C. In vertebrates, SV2s are 12-transmembrane proteins present on every secretory vesicle, including synaptic vesicles, and are critical to neurotransmission. Structural and functional studies suggest that SV2 proteins may play several roles to promote proper vesicular function. Among these roles are their potential to stabilize the transmitter content of vesicles, to maintain and orient the releasable pool of vesicles, and to regulate vesicular calcium sensitivity to ensure efficient, coordinated release of the transmitter. The SV2 family is highly relevant to human health in a number of ways. First, SV2A plays a role in neuronal excitability and as such is the specific target for the antiepileptic drug levetiracetam. SV2 proteins also act as the target by which potent neurotoxins, particularly botulinum, gain access to neurons and exert their toxicity. Both SV2B and SV2C are increasingly implicated in diseases such as Alzheimer's disease and Parkinson's disease. Interestingly, despite decades of intensive research, their exact function remains elusive. Thus, SV2 proteins are intriguing in their potentially diverse roles within the presynaptic terminal, and several recent developments have enhanced our understanding and appreciation of the protein family. Here, we review the structure and function of SV2 proteins as well as their relevance to disease and therapeutic development.
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Affiliation(s)
- Kristen A Stout
- Department of Physiology , Northwestern University, Feinberg School of Medicine , Chicago , Illinois , United States
| | - Amy R Dunn
- The Jackson Laboratory , Bar Harbor , Maine , United States
| | - Carlie Hoffman
- Department of Environmental Health, Rollins School of Public Health , Emory University , Atlanta , Georgia , United States
| | - Gary W Miller
- Department of Environmental Health Sciences, Mailman School of Public Health , Columbia University , New York , New York , United States
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19
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Maulik M, Mitra S, Basmayor AM, Lu B, Taylor BE, Bult-Ito A. Genetic Silencing of Fatty Acid Desaturases Modulates α-Synuclein Toxicity and Neuronal Loss in Parkinson-Like Models of C. elegans. Front Aging Neurosci 2019; 11:207. [PMID: 31447665 PMCID: PMC6691153 DOI: 10.3389/fnagi.2019.00207] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 07/22/2019] [Indexed: 01/14/2023] Open
Abstract
The molecular basis of Parkinson's disease (PD) is currently unknown. There is increasing evidence that fat metabolism is at the crossroad of key molecular pathways associated with the pathophysiology of PD. Fatty acid desaturases catalyze synthesis of saturated fatty acids from monounsaturated fatty acids thereby mediating several cellular mechanisms that are associated with diseases including cancer and metabolic disorders. The role of desaturases in modulating age-related neurodegenerative manifestations such as PD is poorly understood. Here, we investigated the effect of silencing Δ9 desaturase enzyme encoding fat-5 and fat-7 genes which are known to reduce fat content, on α-synuclein expression, neuronal morphology and dopamine-related behaviors in transgenic PD-like models of Caenorhabditis elegans (C. elegans). The silencing of the fat-5 and fat-7 genes rescued both degeneration of dopamine neurons and deficits in dopamine-dependent behaviors, including basal slowing and ethanol avoidance in worm models of PD. Similarly, silencing of these genes also decreased the formation of protein aggregates in a nematode model of PD expressing α-synuclein in the body wall muscles and rescued deficits in resistance to heat and osmotic stress. On the contrary, silencing of nhr-49 and tub-1 genes that are known to increase total fat content did not alter behavioral and pathological endpoints in the PD worm strains. Interestingly, the genetic manipulation of all four selected genes resulted in differential fat levels in the PD models without having significant effect on the lifespan, further indicating a complex fat homeostasis unique to neurodegenerative pathophysiology. Overall, we provide a comprehensive understanding of how Δ9 desaturase can alter PD-like pathology due to environmental exposures and proteotoxic stress, suggesting new avenues in deciphering the disease etiology and possible therapeutic targets.
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Affiliation(s)
- Malabika Maulik
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States
- Biomedical Learning and Student Training (BLaST) Program, University of Alaska Fairbanks, Fairbanks, AK, United States
- Department of Oral Biology, University at Buffalo, The State University of New York at Buffalo, Buffalo, NY, United States
| | - Swarup Mitra
- Program in Neuroscience, Department of Pharmacology and Toxicology, The Research Institution on Addiction, The State University of New York at Buffalo, Buffalo, NY, United States
| | - Ajiel Mae Basmayor
- Biomedical Learning and Student Training (BLaST) Program, University of Alaska Fairbanks, Fairbanks, AK, United States
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Brianna Lu
- Biomedical Learning and Student Training (BLaST) Program, University of Alaska Fairbanks, Fairbanks, AK, United States
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Barbara E. Taylor
- Department of Biological Sciences and College of Natural Sciences and Mathematics, California State University at Long Beach, Long Beach, CA, United States
| | - Abel Bult-Ito
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, United States
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20
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Kochmanski J, VanOeveren SE, Patterson JR, Bernstein AI. Developmental Dieldrin Exposure Alters DNA Methylation at Genes Related to Dopaminergic Neuron Development and Parkinson's Disease in Mouse Midbrain. Toxicol Sci 2019; 169:593-607. [PMID: 30859219 PMCID: PMC6542339 DOI: 10.1093/toxsci/kfz069] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human and animal studies have shown that exposure to the organochlorine pesticide dieldrin is associated with increased risk of Parkinson's disease (PD). Despite previous work showing a link between developmental dieldrin exposure and increased neuronal susceptibility to MPTP toxicity in male C57BL/6 mice, the mechanism mediating this effect has not been identified. Here, we tested the hypothesis that developmental exposure to dieldrin increases neuronal susceptibility via genome-wide changes in DNA methylation. Starting at 8 weeks of age and prior to mating, female C57BL/6 mice were exposed to 0.3 mg/kg dieldrin by feeding (every 3 days) throughout breeding, gestation, and lactation. At 12 weeks of age, pups were sacrificed and ventral mesencephalon, containing primarily substantia nigra, was microdissected. DNA was isolated and dieldrin-related changes in DNA methylation were assessed via reduced representation bisulfite sequencing. We identified significant, sex-specific differentially methylated CpGs (DMCs) and regions (DMRs) by developmental dieldrin exposure (false discovery rate < 0.05), including DMCs at the Nr4a2 and Lmx1b genes, which are involved in dopaminergic neuron development and maintenance. Developmental dieldrin exposure had distinct effects on the male and female epigenome. Together, our data suggest that developmental dieldrin exposure establishes sex-specific poised epigenetic states early in life. These poised epigenomes may mediate sensitivity to subsequent toxic stimuli and contribute to the development of late-life neurodegenerative disease, including PD.
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Affiliation(s)
- Joseph Kochmanski
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan 49503
| | - Sarah E VanOeveren
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan 49503
| | - Joseph R Patterson
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan 49503
| | - Alison I Bernstein
- Department of Translational Science & Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan 49503
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21
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Bruning JM, Wang Y, Oltrabella F, Tian B, Kholodar SA, Liu H, Bhattacharya P, Guo S, Holton JM, Fletterick RJ, Jacobson MP, England PM. Covalent Modification and Regulation of the Nuclear Receptor Nurr1 by a Dopamine Metabolite. Cell Chem Biol 2019; 26:674-685.e6. [PMID: 30853418 PMCID: PMC7185887 DOI: 10.1016/j.chembiol.2019.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 11/06/2018] [Accepted: 01/31/2019] [Indexed: 12/20/2022]
Abstract
Nurr1, a nuclear receptor essential for the development, maintenance, and survival of midbrain dopaminergic neurons, is a potential therapeutic target for Parkinson's disease, a neurological disorder characterized by the degeneration of these same neurons. Efforts to identify Nurr1 agonists have been hampered by the recognition that it lacks several classic regulatory elements of nuclear receptor function, including the canonical ligand-binding pocket. Here we report that the dopamine metabolite 5,6-dihydroxyindole (DHI) binds directly to and modulates the activity of Nurr1. Using biophysical assays and X-ray crystallography, we show that DHI binds to the ligand-binding domain within a non-canonical pocket, forming a covalent adduct with Cys566. In cultured cells and zebrafish, DHI stimulates Nurr1 activity, including the transcription of target genes underlying dopamine homeostasis. These findings suggest avenues for developing synthetic Nurr1 ligands to ameliorate the symptoms and progression of Parkinson's disease.
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Affiliation(s)
- John M Bruning
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California San Francisco, San Francisco, CA 94158, USA
| | - Yan Wang
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Francesca Oltrabella
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| | - Boxue Tian
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Svetlana A Kholodar
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Harrison Liu
- Bioengineering Graduate Program, University of California San Francisco, San Francisco, CA 94158, USA
| | - Paulomi Bhattacharya
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Su Guo
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| | - James M Holton
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Robert J Fletterick
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA
| | - Pamela M England
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA.
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22
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Jorge-Finnigan A, Kleppe R, Jung-Kc K, Ying M, Marie M, Rios-Mondragon I, Salvatore MF, Saraste J, Martinez A. Phosphorylation at serine 31 targets tyrosine hydroxylase to vesicles for transport along microtubules. J Biol Chem 2017. [PMID: 28637871 DOI: 10.1074/jbc.m116.762344] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tyrosine hydroxylase (TH) catalyzes the conversion of l-tyrosine into l-DOPA, which is the rate-limiting step in the synthesis of catecholamines, such as dopamine, in dopaminergergic neurons. Low dopamine levels and death of the dopaminergic neurons are hallmarks of Parkinson's disease (PD), where α-synuclein is also a key player. TH is highly regulated, notably by phosphorylation of several Ser/Thr residues in the N-terminal tail. However, the functional role of TH phosphorylation at the Ser-31 site (THSer(P)-31) remains unclear. Here, we report that THSer(P)-31 co-distributes with the Golgi complex and synaptic-like vesicles in rat and human dopaminergic cells. We also found that the TH microsomal fraction content decreases after inhibition of cyclin-dependent kinase 5 (Cdk5) and ERK1/2. The cellular distribution of an overexpressed phospho-null mutant, TH1-S31A, was restricted to the soma of neuroblastoma cells, with decreased association with the microsomal fraction, whereas a phospho-mimic mutant, TH1-S31E, was distributed throughout the soma and neurites. TH1-S31E associated with vesicular monoamine transporter 2 (VMAT2) and α-synuclein in neuroblastoma cells, and endogenous THSer(P)-31 was detected in VMAT2- and α-synuclein-immunoprecipitated mouse brain samples. Microtubule disruption or co-transfection with α-synuclein A53T, a PD-associated mutation, caused TH1-S31E accumulation in the cell soma. Our results indicate that Ser-31 phosphorylation may regulate TH subcellular localization by enabling its transport along microtubules, notably toward the projection terminals. These findings disclose a new mechanism of TH regulation by phosphorylation and reveal its interaction with key players in PD, opening up new research avenues for better understanding dopamine synthesis in physiological and pathological states.
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Affiliation(s)
- Ana Jorge-Finnigan
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway.
| | - Rune Kleppe
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Kunwar Jung-Kc
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Ming Ying
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Michael Marie
- Department of Molecular Biology, University of Bergen, Thormøhlensgaten 55, 5020 Bergen Norway
| | - Ivan Rios-Mondragon
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Michael F Salvatore
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas 76107
| | - Jaakko Saraste
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Aurora Martinez
- From the Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; K. G. Jebsen Centre for Neuropsychiatric Disorders, Jonas Lies vei 91, 5009 Bergen, Norway
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23
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MPTP Mouse Model of Preclinical and Clinical Parkinson’s Disease as an Instrument for Translational Medicine. Mol Neurobiol 2017; 55:2991-3006. [DOI: 10.1007/s12035-017-0559-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/12/2017] [Indexed: 02/04/2023]
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24
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Cliburn RA, Dunn AR, Stout KA, Hoffman CA, Lohr KM, Bernstein AI, Winokur EJ, Burkett J, Schmitz Y, Caudle WM, Miller GW. Immunochemical localization of vesicular monoamine transporter 2 (VMAT2) in mouse brain. J Chem Neuroanat 2016; 83-84:82-90. [PMID: 27836486 DOI: 10.1016/j.jchemneu.2016.11.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/31/2016] [Accepted: 11/04/2016] [Indexed: 12/16/2022]
Abstract
Vesicular monoamine transporter 2 (VMAT2, SLC18A2) is a transmembrane transporter protein that packages dopamine, serotonin, norepinephrine, and histamine into vesicles in preparation for neurotransmitter release from the presynaptic neuron. VMAT2 function and related vesicle dynamics have been linked to susceptibility to oxidative stress, exogenous toxicants, and Parkinson's disease. To address a recent depletion of commonly used antibodies to VMAT2, we generated and characterized a novel rabbit polyclonal antibody generated against a 19 amino acid epitope corresponding to an antigenic sequence within the C-terminal tail of mouse VMAT2. We used genetic models of altered VMAT2 expression to demonstrate that the antibody specifically recognizes VMAT2 and localizes to synaptic vesicles. Furthermore, immunohistochemical labeling using this VMAT2 antibody produces immunoreactivity that is consistent with expected VMAT2 regional distribution. We show the distribution of VMAT2 in monoaminergic brain regions of mouse brain, notably the midbrain, striatum, olfactory tubercle, dopaminergic paraventricular nuclei, tuberomammillary nucleus, raphe nucleus, and locus coeruleus. Normal neurotransmitter vesicle dynamics are critical for proper health and functioning of the nervous system, and this well-characterized VMAT2 antibody will be a useful tool in studying neurodegenerative and neuropsychiatric conditions characterized by vesicular dysfunction.
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Affiliation(s)
- Rachel A Cliburn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States.
| | - Amy R Dunn
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Carlie A Hoffman
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Kelly M Lohr
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Alison I Bernstein
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Emily J Winokur
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - James Burkett
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Yvonne Schmitz
- Department of Neurology, Columbia University Medical Center, New York City, NY 10032, United States
| | - William M Caudle
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Department of Pharmacology, Department of Neurology, Center for Neurodegenerative Diseases, Emory University, Atlanta, GA 30322, United States.
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25
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German CL, Baladi MG, McFadden LM, Hanson GR, Fleckenstein AE. Regulation of the Dopamine and Vesicular Monoamine Transporters: Pharmacological Targets and Implications for Disease. Pharmacol Rev 2016; 67:1005-24. [PMID: 26408528 DOI: 10.1124/pr.114.010397] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dopamine (DA) plays a well recognized role in a variety of physiologic functions such as movement, cognition, mood, and reward. Consequently, many human disorders are due, in part, to dysfunctional dopaminergic systems, including Parkinson's disease, attention deficit hyperactivity disorder, and substance abuse. Drugs that modify the DA system are clinically effective in treating symptoms of these diseases or are involved in their manifestation, implicating DA in their etiology. DA signaling and distribution are primarily modulated by the DA transporter (DAT) and by vesicular monoamine transporter (VMAT)-2, which transport DA into presynaptic terminals and synaptic vesicles, respectively. These transporters are regulated by complex processes such as phosphorylation, protein-protein interactions, and changes in intracellular localization. This review provides an overview of 1) the current understanding of DAT and VMAT2 neurobiology, including discussion of studies ranging from those conducted in vitro to those involving human subjects; 2) the role of these transporters in disease and how these transporters are affected by disease; and 3) and how selected drugs alter the function and expression of these transporters. Understanding the regulatory processes and the pathologic consequences of DAT and VMAT2 dysfunction underlies the evolution of therapeutic development for the treatment of DA-related disorders.
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Affiliation(s)
- Christopher L German
- School of Dentistry (C.L.G., M.G.B., G.R.H., A.E.F.) and Department of Pharmacology and Toxicology (L.M.M., G.R.H.), University of Utah, Salt Lake City, Utah
| | - Michelle G Baladi
- School of Dentistry (C.L.G., M.G.B., G.R.H., A.E.F.) and Department of Pharmacology and Toxicology (L.M.M., G.R.H.), University of Utah, Salt Lake City, Utah
| | - Lisa M McFadden
- School of Dentistry (C.L.G., M.G.B., G.R.H., A.E.F.) and Department of Pharmacology and Toxicology (L.M.M., G.R.H.), University of Utah, Salt Lake City, Utah
| | - Glen R Hanson
- School of Dentistry (C.L.G., M.G.B., G.R.H., A.E.F.) and Department of Pharmacology and Toxicology (L.M.M., G.R.H.), University of Utah, Salt Lake City, Utah
| | - Annette E Fleckenstein
- School of Dentistry (C.L.G., M.G.B., G.R.H., A.E.F.) and Department of Pharmacology and Toxicology (L.M.M., G.R.H.), University of Utah, Salt Lake City, Utah
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26
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Efficient and biologically relevant consensus strategy for Parkinson's disease gene prioritization. BMC Med Genomics 2016; 9:12. [PMID: 26961748 PMCID: PMC4784386 DOI: 10.1186/s12920-016-0173-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 03/01/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The systemic information enclosed in microarray data encodes relevant clues to overcome the poorly understood combination of genetic and environmental factors in Parkinson's disease (PD), which represents the major obstacle to understand its pathogenesis and to develop disease-modifying therapeutics. While several gene prioritization approaches have been proposed, none dominate over the rest. Instead, hybrid approaches seem to outperform individual approaches. METHODS A consensus strategy is proposed for PD related gene prioritization from mRNA microarray data based on the combination of three independent prioritization approaches: Limma, machine learning, and weighted gene co-expression networks. RESULTS The consensus strategy outperformed the individual approaches in terms of statistical significance, overall enrichment and early recognition ability. In addition to a significant biological relevance, the set of 50 genes prioritized exhibited an excellent early recognition ability (6 of the top 10 genes are directly associated with PD). 40 % of the prioritized genes were previously associated with PD including well-known PD related genes such as SLC18A2, TH or DRD2. Eight genes (CCNH, DLK1, PCDH8, SLIT1, DLD, PBX1, INSM1, and BMI1) were found to be significantly associated to biological process affected in PD, representing potentially novel PD biomarkers or therapeutic targets. Additionally, several metrics of standard use in chemoinformatics are proposed to evaluate the early recognition ability of gene prioritization tools. CONCLUSIONS The proposed consensus strategy represents an efficient and biologically relevant approach for gene prioritization tasks providing a valuable decision-making tool for the study of PD pathogenesis and the development of disease-modifying PD therapeutics.
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Alter SP, Stout KA, Lohr KM, Taylor TN, Shepherd KR, Wang M, Guillot TS, Miller GW. Reduced vesicular monoamine transport disrupts serotonin signaling but does not cause serotonergic degeneration. Exp Neurol 2015; 275 Pt 1:17-24. [PMID: 26428905 DOI: 10.1016/j.expneurol.2015.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/11/2015] [Accepted: 09/26/2015] [Indexed: 10/23/2022]
Abstract
We previously demonstrated that mice with reduced expression of the vesicular monoamine transporter 2 (VMAT2 LO) undergo age-related degeneration of the catecholamine-producing neurons of the substantia nigra pars compacta and locus ceruleus and exhibit motor disturbances and depressive-like behavior. In this work, we investigated the effects of reduced vesicular transport on the function and viability of serotonin neurons in these mice. Adult (4-6 months of age), VMAT2 LO mice exhibit dramatically reduced (90%) serotonin release capacity, as measured by fast scan cyclic voltammetry. We observed changes in serotonin receptor responsivity in in vivo pharmacological assays. Aged (months) VMAT2 LO mice exhibited abolished 5-HT1A autoreceptor sensitivity, as determined by 8-OH-DPAT (0.1 mg/kg) induction of hypothermia. When challenged with the 5HT2 agonist, 2,5-dimethoxy-4-iodoamphetamine (1 mg/kg), VMAT2 LO mice exhibited a marked increase (50%) in head twitch responses. We observed sparing of serotonergic terminals in aged mice (18-24 months) throughout the forebrain by SERT immunohistochemistry and [(3)H]-paroxetine binding in striatal homogenates of aged VMAT2 LO mice. In contrast to their loss of catecholamine neurons of the substantia nigra and locus ceruleus, aged VMAT2 LO mice do not exhibit a change in the number of serotonergic (TPH2+) neurons within the dorsal raphe, as measured by unbiased stereology at 26-30 months. Collectively, these data indicate that reduced vesicular monoamine transport significantly disrupts serotonergic signaling, but does not drive degeneration of serotonin neurons.
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Affiliation(s)
- Shawn P Alter
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kelly M Lohr
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Tonya N Taylor
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Kennie R Shepherd
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Minzheng Wang
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Thomas S Guillot
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States; Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, United States.
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Lohr KM, Stout KA, Dunn AR, Wang M, Salahpour A, Guillot TS, Miller GW. Increased Vesicular Monoamine Transporter 2 (VMAT2; Slc18a2) Protects against Methamphetamine Toxicity. ACS Chem Neurosci 2015; 6:790-9. [PMID: 25746685 DOI: 10.1021/acschemneuro.5b00010] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The psychostimulant methamphetamine (METH) is highly addictive and neurotoxic to dopamine terminals. METH toxicity has been suggested to be due to the release and accumulation of dopamine in the cytosol of these terminals. The vesicular monoamine transporter 2 (VMAT2; SLC18A2) is a critical mediator of dopamine handling. Mice overexpressing VMAT2 (VMAT2-HI) have an increased vesicular capacity to store dopamine, thus augmenting striatal dopamine levels and dopamine release in the striatum. Based on the altered compartmentalization of intracellular dopamine in the VMAT2-HI mice, we assessed whether enhanced vesicular function was capable of reducing METH-induced damage to the striatal dopamine system. While wildtype mice show significant losses in striatal levels of the dopamine transporter (65% loss) and tyrosine hydroxylase (46% loss) following a 4 × 10 mg/kg METH dosing regimen, VMAT2-HI mice were protected from this damage. VMAT2-HI mice were also spared from the inflammatory response that follows METH treatment, showing an increase in astroglial markers that was approximately one-third of that of wildtype animals (117% vs 36% increase in GFAP, wildtype vs VMAT2-HI). Further analysis also showed that elevated VMAT2 level does not alter the ability of METH to increase core body temperature, a mechanism integral to the toxicity of the drug. Finally, the VMAT2-HI mice showed no difference from wildtype littermates on both METH-induced conditioned place preference and in METH-induced locomotor activity (1 mg/kg METH). These results demonstrate that elevated VMAT2 protects against METH toxicity without enhancing the rewarding effects of the drug. Since the VMAT2-HI mice are protected from METH despite higher basal dopamine levels, this study suggests that METH toxicity depends more on the proper compartmentalization of synaptic dopamine than on the absolute amount of dopamine in the brain.
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Affiliation(s)
| | | | | | | | - Ali Salahpour
- Department
of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Increased vesicular monoamine transporter enhances dopamine release and opposes Parkinson disease-related neurodegeneration in vivo. Proc Natl Acad Sci U S A 2014; 111:9977-82. [PMID: 24979780 DOI: 10.1073/pnas.1402134111] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Disruption of neurotransmitter vesicle dynamics (transport, capacity, release) has been implicated in a variety of neurodegenerative and neuropsychiatric conditions. Here, we report a novel mouse model of enhanced vesicular function via bacterial artificial chromosome (BAC)-mediated overexpression of the vesicular monoamine transporter 2 (VMAT2; Slc18a2). A twofold increase in vesicular transport enhances the vesicular capacity for dopamine (56%), dopamine vesicle volume (33%), and basal tissue dopamine levels (21%) in the mouse striatum. The elevated vesicular capacity leads to an increase in stimulated dopamine release (84%) and extracellular dopamine levels (44%). VMAT2-overexpressing mice show improved outcomes on anxiety and depressive-like behaviors and increased basal locomotor activity (41%). Finally, these mice exhibit significant protection from neurotoxic insult by the dopaminergic toxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), as measured by reduced dopamine terminal damage and substantia nigra pars compacta cell loss. The increased release of dopamine and neuroprotection from MPTP toxicity in the VMAT2-overexpressing mice suggest that interventions aimed at enhancing vesicular capacity may be of therapeutic benefit in Parkinson disease.
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Ouazia D, Levros LC, Rassart E, Desrosiers RR. Dopamine down-regulation of protein L-isoaspartyl methyltransferase is dependent on reactive oxygen species in SH-SY5Y cells. Neuroscience 2014; 267:263-76. [PMID: 24631677 DOI: 10.1016/j.neuroscience.2014.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 02/18/2014] [Accepted: 03/02/2014] [Indexed: 12/21/2022]
Abstract
Parkinson's disease (PD) is a chronic and progressive neurological disorder that is characterized by the loss of dopaminergic neurons in the substantia nigra. Dopamine, via the oxidative stress that it generates in the cytosol, could contribute to the selective loss of neurons observed in PD. Protein L-isoaspartyl methyltransferase (PIMT) is an enzyme that repairs L-isoaspartyl-containing proteins and possesses anti-apoptotic properties. PIMT expression has been shown to decrease with age. Together, these observations prompted us to investigate whether dopamine can regulate PIMT expression in SH-SY5Y neuroblastoma cells. Here, we report that dopamine down-regulated PIMT at both gene and protein levels. The same inhibition of PIMT protein level was caused by the electron transport chain inhibitor, rotenone, which was accompanied, in both cases, by an increase in cell death and reactive oxygen species (ROS) production. In fact, pre-treatment with the antioxidant N-acetyl cysteine blocked PIMT dopamine-associated down-regulation. PCMT1 promoter mapping experiments allowed the identification of two regions that showed different sensitivity to DA action. A first region localized between 61 and 94bp upstream of transcription start site was very sensitive to dopamine inhibition while a second region between 41 and 61bp appeared more resistant to dopamine inhibitory effect. The inhibition of PCMT1 promoter activity was mediated by dopamine-induced ROS since it was prevented by the hydroxyl radical scavenger N,N'-dimethylthiourea. Conversely, H2O2 inhibited in a dose-dependent manner the transcriptional activity of PCMT1 promoter. Therefore, our findings identified new molecular mechanisms, cytosolic dopamine and its resulting ROS, as inhibitors of PIMT expression. This suggests that ROS generated from cytosolic dopamine could reduce both the PCMT1 gene promoter activity and the PIMT protein level thus decreasing its capacity to repair proteins involved in apoptosis and could contribute to neuronal cell death observed in PD.
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Affiliation(s)
- D Ouazia
- Université du Québec à Montréal, Département de chimie, C.P. 8888, Succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada
| | - L-C Levros
- Laboratoire de Biologie Moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada
| | - E Rassart
- Laboratoire de Biologie Moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada
| | - R R Desrosiers
- Université du Québec à Montréal, Département de chimie, C.P. 8888, Succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada.
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Bernstein AI, Stout KA, Miller GW. The vesicular monoamine transporter 2: an underexplored pharmacological target. Neurochem Int 2014; 73:89-97. [PMID: 24398404 DOI: 10.1016/j.neuint.2013.12.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 12/21/2022]
Abstract
Active transport of neurotransmitters into synaptic vesicles is required for their subsequent exocytotic release. In the monoamine system, this process is carried out by the vesicular monoamine transporters (VMAT1 and VMAT2). These proteins are responsible for vesicular packaging of dopamine, norepinephrine, serotonin, and histamine. These proteins are essential for proper neuronal function; however, compared to their plasma membrane counterparts, there are few drugs available that target these vesicular proteins. This is partly due to the added complexity of crossing the plasma membrane, but also to the technical difficulty of assaying for vesicular uptake in high throughput. Until recently, reagents to enable high throughput screening for function of these vesicular neurotransmitter transporters have not been available. Fortunately, novel compounds and methods are now making such screening possible; thus, a renewed focus on these transporters as potential targets is timely and necessary.
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Affiliation(s)
- Alison I Bernstein
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Kristen A Stout
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Gary W Miller
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA; Center for Neurodegenerative Diseases, Emory University, Atlanta, GA 30322, USA; Department of Pharmacology, Emory University, Atlanta, GA 30322, USA; Department of Neurology, Emory University, Atlanta, GA 30322, USA.
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Fungal-derived semiochemical 1-octen-3-ol disrupts dopamine packaging and causes neurodegeneration. Proc Natl Acad Sci U S A 2013; 110:19561-6. [PMID: 24218591 DOI: 10.1073/pnas.1318830110] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Parkinson disease (PD) is the most common movement disorder and, although the exact causes are unknown, recent epidemiological and experimental studies indicate that several environmental agents may be significant risk factors. To date, these suspected environmental risk factors have been man-made chemicals. In this report, we demonstrate via genetic, biochemical, and immunological studies that the common volatile fungal semiochemical 1-octen-3-ol reduces dopamine levels and causes dopamine neuron degeneration in Drosophila melanogaster. Overexpression of the vesicular monoamine transporter (VMAT) rescued the dopamine toxicity and neurodegeneration, whereas mutations decreasing VMAT and tyrosine hydroxylase exacerbated toxicity. Furthermore, 1-octen-3-ol also inhibited uptake of dopamine in human cell lines expressing the human plasma membrane dopamine transporter (DAT) and human VMAT ortholog, VMAT2. These data demonstrate that 1-octen-3-ol exerts toxicity via disruption of dopamine homeostasis and may represent a naturally occurring environmental agent involved in parkinsonism.
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