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Omotosho AO, Tajudeen YA, Oladipo HJ, Yusuff SI, AbdulKadir M, Muili AO, Egbewande OM, Yusuf RO, Faniran ZO, Afolabi AO, El‐Sherbini MS. Parkinson's disease: Are gut microbes involved? Brain Behav 2023; 13:e3130. [PMID: 37340511 PMCID: PMC10454343 DOI: 10.1002/brb3.3130] [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: 10/05/2022] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 06/22/2023] Open
Abstract
INTRODUCTION Parkinson's disease (PD) is a neurodegenerative disorder that affects more than 10 million individuals worldwide. It is characterized by motor and sensory deficits. Research studies have increasingly demonstrated a correlation between Parkinson's disease and alternations in the composition of the gut microbiota in affected patients. Also, the significant role of prebiotics and probiotics in gastrointestinal and neurological conditions is imperative to understand their relation to Parkinson's disease. METHOD To explore the scientific interaction of the gut-microbiota-brain axis and its association with Parkinson's disease, a comprehensive narrative review of the relevant literature was conducted. Articles were retrieved systematically from reputable sources, including PubMed, Science Direct, World Health Organization (WHO), and Advanced Google Scholar. Key search terms included are "Parkinson's Disease", "Gut Microbiome", "Braak's Theory", "Neurological Disorders", and "Gut-brain axis". Articles included in our review are published in English and they provide detailed information on the relationship between Parkinson's disease and gut microbiota RESULTS: This review highlights the impact of gut microbiota composition and associated factors on the progression of Parkinson's disease. Evidence-based studies highlighting the existing evidence of the relationship between Parkinson's disease and alteration in gut microbiota are discussed. Consequently, the potential mechanisms by which the gut microbiota may affect the composition of the gut microbiota were revealed, with a particular emphasis on the role of the gut-brain axis in this interplay. CONCLUSION Understanding the complex interplay between gut microbiota and Parkinson's disease is a potential implication for the development of novel therapeutics against Parkinson's disease. Following the existing relationship demonstrated by different evidence-based studies on Parkinson's disease and gut microbiota, our review concludes by providing recommendations and suggestions for future research studies with a particular emphasis on the impact of the microbiota-brain axis on Parkinson's disease.
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Affiliation(s)
- Abass Olawale Omotosho
- Department of Microbiology, Faculty of Pure and Applied SciencesKwara State University, Malete‐IlorinIlorinNigeria
| | - Yusuf Amuda Tajudeen
- Department of Microbiology, Faculty of Life SciencesUniversity of IlorinIlorinNigeria
- Faculty of Pharmaceutical SciencesUniversity of IlorinIlorinNigeria
| | - Habeebullah Jayeola Oladipo
- Department of Microbiology, Faculty of Life SciencesUniversity of IlorinIlorinNigeria
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of MedicineUniversity of IbadanIbadanNigeria
| | - Sodiq Inaolaji Yusuff
- Department of Medicine, Faculty of Clinical SciencesObafemi Awolowo UniversityIfeNigeria
| | - Muritala AbdulKadir
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of MedicineUniversity of IbadanIbadanNigeria
| | | | - Oluwaseyi Muyiwa Egbewande
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of MedicineUniversity of IbadanIbadanNigeria
| | - Rashidat Onyinoyi Yusuf
- Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of MedicineUniversity of IbadanIbadanNigeria
| | | | - Abdullateef Opeyemi Afolabi
- Faculty of Biomedical Sciences, Department of Microbiology and ImmunologyKampala International UniversityBushenyiUganda
| | - Mona Said El‐Sherbini
- Narrative Medicine and Planetary Health, Integrated Program of Kasr Al-Ainy (IPKA), Faculty of MedicineCairo UniversityCairoEgypt
- Invited Facultythe Nova Institute for HealthBaltimoreMDUSA
- Department of Medical Parasitology, Faculty of MedicineCairo UniversityCairoEgypt
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2
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Borsche M, Pereira SL, Klein C, Grünewald A. Mitochondria and Parkinson's Disease: Clinical, Molecular, and Translational Aspects. JOURNAL OF PARKINSONS DISEASE 2021; 11:45-60. [PMID: 33074190 PMCID: PMC7990451 DOI: 10.3233/jpd-201981] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dysfunction represents a well-established player in the pathogenesis of both monogenic and idiopathic Parkinson’s disease (PD). Initially originating from the observation that mitochondrial toxins cause PD, findings from genetic PD supported a contribution of mitochondrial dysfunction to the disease. Here, proteins encoded by the autosomal recessively inherited PD genes Parkin, PTEN-induced kinase 1 (PINK1), and DJ-1 are involved in mitochondrial pathways. Additional evidence for mitochondrial dysfunction stems from models of autosomal-dominant PD due to mutations in alpha-synuclein (SNCA) and leucine-rich repeat kinase 2 (LRRK2). Moreover, patients harboring alterations in mitochondrial polymerase gamma (POLG) often exhibit signs of parkinsonism. While some molecular studies suggest that mitochondrial dysfunction is a primary event in PD, others speculate that it is the result of impaired mitochondrial clearance. Most recent research even implicated damage-associated molecular patterns released from non-degraded mitochondria in neuroinflammatory processes in PD. Here, we summarize the manifold literature dealing with mitochondria in the context of PD. Moreover, in light of recent advances in the field of personalized medicine, patient stratification according to the degree of mitochondrial impairment followed by mitochondrial enhancement therapy may hold potential for at least a subset of genetic and idiopathic PD cases. Thus, in the second part of this review, we discuss therapeutic approaches targeting mitochondrial dysfunction with the aim to prevent or delay neurodegeneration in PD.
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Affiliation(s)
- Max Borsche
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Sandro L Pereira
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Anne Grünewald
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
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Noonong K, Sobhon P, Sroyraya M, Chaithirayanon K. Neuroprotective and Neurorestorative Effects of Holothuria scabra Extract in the MPTP/MPP +-Induced Mouse and Cellular Models of Parkinson's Disease. Front Neurosci 2020; 14:575459. [PMID: 33408606 PMCID: PMC7779621 DOI: 10.3389/fnins.2020.575459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 11/18/2020] [Indexed: 12/13/2022] Open
Abstract
Extracts from Holothuria scabra (HS) have been shown to possess anti-inflammation, anti-oxidant and anti-cancer activities. More recently, it was shown to have neuroprotective potential in Caenorhabditis elegans PD model. Here, we assessed whether HS has neuroprotective and neurorestorative effects on dopaminergic neurons in both mouse and cellular models of PD. We found that both pre-treatment and post-treatment with HS improved motor deficits in PD mouse model induced with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as determined by grid walk test. This was likely mediated by HS protective and restorative effects on maintaining the numbers of dopaminergic neurons and fibers in both substantia nigra pars compacta (SNpc) and striatum. In a cellular model of PD, HS significantly attenuated 1-methyl-4-phenylpyridinium (MPP+)-induced apoptosis of DAergic-like neurons differentiated from SH-SY5Y cells by enhancing the expression of Bcl-2, suppressing the expression of cleaved Caspase 3 and preventing depolarization of mitochondrial membrane. In addition, HS could stimulate the expression of tyrosine hydroxylase (TH) and suppressed the formation of α-synuclein protein. Taken together, our in vivo and in vitro findings suggested that HS is an attractive candidate for the neuroprotection rather than neurorestoration in PD.
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Affiliation(s)
- Kunwadee Noonong
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Prasert Sobhon
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Morakot Sroyraya
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
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Liu H, Chen F, Wang B, Wang H, Jin S, Yang Z, Chen Y, Quan Y, Xiang X. A Sensitive HPLC-MS/MS Method for the Quantification of Selegiline in Beagle Dog Plasma: Application to a Pharmacokinetic Study. CURR PHARM ANAL 2020. [DOI: 10.2174/1573412915666190823102223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objective:
To develop a reliable and sensitive high-performance liquid chromatographytandem
mass spectrometry (HPLC-MS/MS) method for the quantification of selegiline in Beagle dog
plasma and apply the validated method to study the pharmacokinetics and bioavailability of oral selegiline
lyophilizate in Beagle dogs.
Methods:
Following alkalization with 1 M sodium hydroxide solution, selegiline and the Internal
Standard (IS) zolmitriptan were extracted using tert-butyl methyl ether and separated on a CAPCELL
PAK C18 column under isocratic conditions. They were detected by MS/MS using electrospray ionization
(ESI) in the positive mode. Quantification was performed using multiple reaction monitoring
(MRM) with transitions of m/z 188.05→90.9 for selegiline and m/z 288.05→57.95 for IS.
Results:
Calibration curves were constructed in the concentration range of 0.2–200 ng/mL with a lower
limit of quantification (LLOQ) of 0.21 ng/mL. The matrix effect of dog plasma on the selegiline signal
ranged from 98.8 to 105.6%, and the mean extraction recovery ranged from 79.0% to 81.4% at concentrations
of 1.04, 20.8, and 166 ng/mL. The intra-day precision was lower than 6.86% and the inter-day
precisions were lower than 4.63%.
Conclusion:
The validation results demonstrated the reliability of this bioanalytical method, which was
successfully applied to study the pharmacokinetics and bioavailability of 1.25 mg of orally administered
selegiline lyophilizate in Beagle dogs. The pharmacokinetic results were also compared with
those obtained following intragastric (i.g.) and intravenous (i.v.) administration. Buccal delivery of
selegiline was found to significantly increase its bioavailability.
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Affiliation(s)
- Hongrui Liu
- National Pharmaceutical Engineering Research Center, China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Fang Chen
- National Pharmaceutical Engineering Research Center, China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Bing Wang
- National Pharmaceutical Engineering Research Center, China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Hao Wang
- National Pharmaceutical Engineering Research Center, China State Institute of Pharmaceutical Industry, Shanghai, China
| | - Shasha Jin
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University, Shanghai, China
| | - Zhou Yang
- Department of General Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Yusheng Chen
- Department of General Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Yingjun Quan
- Department of General Surgery, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Xiaoqiang Xiang
- Department of Clinical Pharmacy, School of Pharmacy, Fudan University, Shanghai, China
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Libard S, Laurell K, Cesarini KG, Alafuzoff I. Progression of Alzheimer's Disease-Related Pathology and Cell Counts in a Patient with Idiopathic Normal Pressure Hydrocephalus. J Alzheimers Dis 2019; 61:1451-1462. [PMID: 29376849 DOI: 10.3233/jad-170446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We had an opportunity to assess the change observed in the brain regarding Alzheimer's disease (AD)-related alterations, cell count, and inflammation that took place during a period of 21 months in a subject with a definite diagnosis of AD and idiopathic Normal Pressure Hydrocephalus (iNPH). Four neuronal markers, i.e., synaptophysin, microtubule associated protein 2, non-phosphorylated neurofilament H (SMI32), and embryonic lethal abnormal visual system proteins 3/4 HuC/HuD (HuC/HuD); three microglial markers CD68, Human Leucocytic Antigen DR, ionized calcium-binding adaptor molecule 1, glial fibrillary acidic protein (GFAP); and AD-related markers, hyperphosphorylated τ (HPτ) and amyloid-β (Aβ, Aβ40, Aβ42) were assessed. Morphometrically assessed immunoreactivity of all neuronal and all microglial markers and Aβ42 decreased parallel with an increase in the HPτ in the frontal cortex. The expression of GFAP was stable with time. The first sample was obtained during the therapeutic shunting procedure for iNPH, and the second sample was obtained postmortem. Negligible reactive changes were observed surrounding the shunt channel. In conclusion, in the late stage of AD with time, a neuronal loss, increase in the HPτ, and decrease in Aβ42 and microglia was observed, whereas the expression of GFAP was rather stable. The observations described here suggest that when a brain biopsy has been obtained from an adult subject with iNPH, the assessment of postmortem brain is of major significance.
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Affiliation(s)
- Sylwia Libard
- Department of Immunology, Genetics and Pathology, Uppsala University, Sweden.,Department of Pathology, Uppsala University Hospital, Sweden
| | - Katarina Laurell
- Department of Pharmacology and Clinical Neuroscience, Östersund, Umeå University, Sweden
| | | | - Irina Alafuzoff
- Department of Immunology, Genetics and Pathology, Uppsala University, Sweden.,Department of Pathology, Uppsala University Hospital, Sweden
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Alborghetti M, Nicoletti F. Different Generations of Type-B Monoamine Oxidase Inhibitors in Parkinson's Disease: From Bench to Bedside. Curr Neuropharmacol 2019; 17:861-873. [PMID: 30160213 PMCID: PMC7052841 DOI: 10.2174/1570159x16666180830100754] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/06/2018] [Accepted: 08/29/2018] [Indexed: 12/21/2022] Open
Abstract
Three inhibitors of type-B monoamine oxidase (MAOB), selegiline, rasagiline, and safinamide, are used for the treatment of Parkinson's disease (PD). All three drugs improve motor signs of PD, and are effective in reducing motor fluctuations in patients undergoing long-term L-DOPA treatment. The effect of MAOB inhibitors on non-motor symptoms is not uniform and may not be class-related. Selegiline and rasagiline are irreversible inhibitors forming a covalent bond within the active site of MAOB. In contrast, safinamide is a reversible MAOB inhibitor, and also inhibits voltage- sensitive sodium channels and glutamate release. Safinamide is the prototype of a new generation of multi-active MAOB inhibitors, which includes the antiepileptic drug, zonisamide. Inhibition of MAOB-mediated dopamine metabolism largely accounts for the antiparkinsonian effect of the three drugs. Dopamine metabolism by MAOB generates reactive oxygen species, which contribute to nigro-striatal degeneration. Among all antiparkinsonian agents, MAOB inhibitors are those with the greatest neuroprotective potential because of inhibition of dopamine metabolism, induction of neurotrophic factors, and, in the case of safinamide, inhibition of glutamate release. The recent development of new experimental animal models that more closely mimic the progressive neurodegeneration associated with PD will allow to test the hypothesis that MAOB inhibitors may slow the progression of PD.
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Affiliation(s)
| | - Ferdinando Nicoletti
- Address correspondence to this author at the Department of Physiology and Pharmacology, University Sapienza of Rome, Piazzale Aldo Moro, 5, 00185, Rome, Italy; Tel: 39-3662816464; E-mail:
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7
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Xiao SJ, Zhu XC, Deng H, Zhou WP, Yang WY, Yuan LK, Zhang JY, Tian S, Xu L, Zhang L, Xia HM. Gene expression profiling coupled with Connectivity Map database mining reveals potential therapeutic drugs for Hirschsprung disease. J Pediatr Surg 2018; 53:1716-1721. [PMID: 29605259 DOI: 10.1016/j.jpedsurg.2018.02.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 02/12/2018] [Accepted: 02/27/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND Hirschsprung disease (HD) is a congenital intestinal anomaly resulting from a failure to form enteric ganglia in the lower bowel. Surgery is the main therapeutic strategy, although neural stem cell transplantation has recently shown promise. However, HD remains a challenging disorder to treat. Our aim was to identify drugs that could counteract the dysregulated pathways in HD and could thus be potential novel therapies. METHODS We used microarray analysis to identify genes differentially expressed in ganglionic and aganglionic bowel samples from eight children with HD. The signature of differentially expressed genes was then used as a search query to explore the Connectivity Map (cMAP), a transcriptional expression database that catalogs gene signatures elicited by chemical perturbagens. RESULTS We uncovered several dysregulated signaling pathways, and in particular regulation of neuron development, in HD. The cMAP search identified some compounds with the potential to counteract the effects of the dysregulated molecular signature in this disease. One of these, pepstatin A, was recently shown to rescue the migration defects observed in a mouse model of HD, providing strong support for our findings. CONCLUSIONS This study advances our understanding of the molecular changes in HD and identifies several potential pharmacological interventions. Further testing of the identified compounds is warranted.
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Affiliation(s)
- Shang-Jie Xiao
- Department of Neonatal Surgery, Guangdong Women and Children Hospital, Guangzhou, China
| | - Xiao-Chun Zhu
- Department of Neonatal Surgery, Guangdong Women and Children Hospital, Guangzhou, China
| | - Hua Deng
- Translational Medicine Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Wei-Ping Zhou
- Translational Medicine Center, Guangdong Women and Children Hospital, Guangzhou, China
| | - Wen-Yi Yang
- Department of Neonatology, Guangdong Women and Children Hospital, Guangzhou, China
| | - Li-Ke Yuan
- Department of Neonatal Surgery, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jiang-Yu Zhang
- Department of Pathology, Guangdong Women and Children Hospital, Guangzhou, China
| | - Song Tian
- Department of Neonatal Surgery, Guangdong Women and Children Hospital, Guangzhou, China
| | - Lu Xu
- Department of Neonatal Surgery, Guangdong Women and Children Hospital, Guangzhou, China
| | - Liang Zhang
- Translational Medicine Center, Guangdong Women and Children Hospital, Guangzhou, China.
| | - Hui-Min Xia
- Department of Pediatric Surgery, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
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8
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Szökő É, Tábi T, Riederer P, Vécsei L, Magyar K. Pharmacological aspects of the neuroprotective effects of irreversible MAO-B inhibitors, selegiline and rasagiline, in Parkinson's disease. J Neural Transm (Vienna) 2018; 125:1735-1749. [PMID: 29417334 DOI: 10.1007/s00702-018-1853-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/31/2018] [Indexed: 11/24/2022]
Abstract
The era of MAO-B inhibitors dates back more than 50 years. It began with Kálmán Magyar's outstanding discovery of the selective inhibitor, selegiline. This compound is still regarded as the gold standard of MAO-B inhibition, although newer drugs have also been introduced to the field. It was revealed early on that selective, even irreversible inhibition of MAO-B is free from the severe side effect of the non-selective MAO inhibitors, the potentiation of tyramine, resulting in the so-called 'cheese effect'. Since MAO-B is involved mainly in the degradation of dopamine, the inhibitors lack any antidepressant effect; however, they became first-line medications for the therapy of Parkinson's disease based on their dopamine-sparing activity. Extensive studies with selegiline indicated its complex pharmacological activity profile with MAO-B-independent mechanisms involved. Some of these beneficial effects, such as neuroprotective and antiapoptotic properties, were connected to its propargylamine structure. The second MAO-B inhibitor approved for the treatment of Parkinson's disease, rasagiline also possesses this structural element and shows similar pharmacological characteristics. The preclinical studies performed with selegiline and rasagiline are summarized in this review.
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Affiliation(s)
- Éva Szökő
- Department of Pharmacodynamics, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Tamás Tábi
- Department of Pharmacodynamics, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Peter Riederer
- Center of Mental Health, Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Magarete-Höppel-Platz 1, 97080, Würzburg, Germany
| | - László Vécsei
- Department of Neurology, University of Szeged, Semmelweis u. 6, Szeged, 6725, Hungary. .,MTA-SZTE Neuroscience Research Group, Semmelweis u. 6, Szeged, 6725, Hungary.
| | - Kálmán Magyar
- Department of Pharmacodynamics, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
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Dulcis D, Lippi G, Stark CJ, Do LH, Berg DK, Spitzer NC. Neurotransmitter Switching Regulated by miRNAs Controls Changes in Social Preference. Neuron 2017; 95:1319-1333.e5. [PMID: 28867550 PMCID: PMC5893310 DOI: 10.1016/j.neuron.2017.08.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 07/12/2017] [Accepted: 08/11/2017] [Indexed: 01/01/2023]
Abstract
Changes in social preference of amphibian larvae result from sustained exposure to kinship odorants. To understand the molecular and cellular mechanisms of this neuroplasticity, we investigated the effects of olfactory system activation on neurotransmitter (NT) expression in accessory olfactory bulb (AOB) interneurons during development. We show that protracted exposure to kin or non-kin odorants changes the number of dopamine (DA)- or gamma aminobutyric acid (GABA)-expressing neurons, with corresponding changes in attraction/aversion behavior. Changing the relative number of dopaminergic and GABAergic AOB interneurons or locally introducing DA or GABA receptor antagonists alters kinship preference. We then isolate AOB microRNAs (miRs) differentially regulated across these conditions. Inhibition of miR-375 and miR-200b reveals that they target Pax6 and Bcl11b to regulate the dopaminergic and GABAergic phenotypes. The results illuminate the role of NT switching governing experience-dependent social preference. VIDEO ABSTRACT.
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Affiliation(s)
- Davide Dulcis
- Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits and Behavior, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA 92093-0357, USA; Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA 92093-0603, USA.
| | - Giordano Lippi
- Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits and Behavior, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA 92093-0357, USA
| | - Christiana J Stark
- Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits and Behavior, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA 92093-0357, USA; Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA 92093-0603, USA
| | - Long H Do
- Department of Neuroscience, University of California San Diego, La Jolla, CA 92093-0649, USA
| | - Darwin K Berg
- Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits and Behavior, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA 92093-0357, USA
| | - Nicholas C Spitzer
- Neurobiology Section, Division of Biological Sciences and Center for Neural Circuits and Behavior, Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA 92093-0357, USA
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Wahdan SA, Tadros MG, Khalifa AE. Antioxidant and antiapoptotic actions of selegiline protect against 3-NP-induced neurotoxicity in rats. Naunyn Schmiedebergs Arch Pharmacol 2017. [DOI: 10.1007/s00210-017-1392-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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11
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Zheng CY, Guo BJ, Cai W, Cui W, Mak SH, Wang YQ, Lee SMY, Han YF, Zhang ZJ. No synergism between bis(propyl)-cognitin and rasagiline on protecting dopaminergic neurons in Parkinson's disease mice. Neural Regen Res 2016; 11:1339-46. [PMID: 27651784 PMCID: PMC5020835 DOI: 10.4103/1673-5374.189201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Rasagiline, a monoamine oxidase-B inhibitor, and bis(propyl)-cognitin (B3C), a novel dimer are reported to be neuroprotective. Herein, the synergistical neuroprotection produced by rasagiline and B3C was investigated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice of Parkinsonism. By using neurobehavioural tests, high-performance liquid chromatography and western blot assay, we showed that B3C at 0.3 mg/kg, rasagiline at 0.02 mg/kg, as well as co-treatment with B3C and rasagiline prevented MPTP-induced behavioural abnormities, increased the concentrations of dopamine and its metabolites in the striatum, and up-regulated the expression of tyrosine hydroxylase in the substantia nigra. However, the neuroprotective effects of co-treatment were not significantly improved when compared with those of B3C or rasagiline alone. Collectively, we have demonstrated that B3C at 0.3 mg/kg and rasagline at 0.02 mg/kg could not produce synergistic neuroprotective effects.
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Affiliation(s)
- Cheng-You Zheng
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardiocerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, Guangdong Province, China
| | - Bao-Jian Guo
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardiocerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, Guangdong Province, China
| | - Wei Cai
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardiocerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, Guangdong Province, China
| | - Wei Cui
- School of Medicine, Ningbo University, Ningbo, Zhejiang Province, China
| | - Shing-Hung Mak
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong Special Administrative Region, China
| | - Yu-Qiang Wang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardiocerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, Guangdong Province, China
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research of Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao Special Administrative Region, China
| | - Yi-Fan Han
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong Special Administrative Region, China
| | - Zai-Jun Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardiocerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, Guangdong Province, China
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Sridharan S, Mohankumar K, Jeepipalli SPK, Sankaramourthy D, Ronsard L, Subramanian K, Thamilarasan M, Raja K, Chandra VK, Sadras SR. Neuroprotective effect of Valeriana wallichii rhizome extract against the neurotoxin MPTP in C57BL/6 mice. Neurotoxicology 2015; 51:172-83. [PMID: 26522450 DOI: 10.1016/j.neuro.2015.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 10/20/2015] [Accepted: 10/26/2015] [Indexed: 01/08/2023]
Abstract
Oxidative stress and inflammation are some of the contributing factors for dopaminergic neurodegeneration in Parkinson's disease (PD). Though Valeriana wallichii D.C. is known for its nervine activities its effect against PD is yet to be studied. This is the first report on the antioxidant and anti-inflammatory effect of V. wallichii rhizome extract (VWE) in MPTP induced PD mice. GC-MS analysis of VWE indicated the presence of phytoconstituents like isovaleric acid and acacetin. PD induced mice were treated orally with three different doses (50, 100 and 200mg/kg body weight (BW)) of VWE for 14 days and their behavioural changes were studied on days 0, 8, 13 and 21. The levels of striatal dopamine, mid brain tyrosine hydroxylase positive (TH(+)) cell count, TH protein expression, reactive oxygen species (ROS), lipid peroxidation (LPO), antioxidants and inflammatory cytokines were analysed. Mid brain glial fibrillary acidic protein (GFAP) expression was assessed by immunohistochemistry and western blotting. Also mid brain histopathological analysis was performed. VWE treatment significantly recuperated the altered behavioural test scores, striatal dopamine levels, mid brain TH(+) cell count and TH protein levels, increased GFAP expression and the histopathological changes observed in PD mice. Similarly, diminished levels of antioxidants, elevated levels of ROS, LPO and inflammatory cytokines were also significantly ameliorated following VWE treatment. The effective dose of VWE was found to be 200mg/kg BW. Conclusively, V. wallichii rhizome extract has the potential to mitigate oxidative stress and inflammatory damage in PD.
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Affiliation(s)
- Subhashree Sridharan
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Kumaravel Mohankumar
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Syam Praveen Kumar Jeepipalli
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Divya Sankaramourthy
- Department of Pharmacology, Mother Theresa Post Graduate and Research Institute of Health Sciences, Puducherry 605006, India
| | - Larance Ronsard
- Virology Laboratory-II, National Institute of Immunology, New Delhi, Delhi 110067, India
| | - Kavimani Subramanian
- Department of Pharmacology, Mother Theresa Post Graduate and Research Institute of Health Sciences, Puducherry 605006, India
| | - Manivasagam Thamilarasan
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar 608002, India
| | - Kumar Raja
- Department of Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Puducherry 605009, India
| | - Varshney Khub Chandra
- Department of Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Puducherry 605009, India
| | - Sudha Rani Sadras
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India.
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Suarez S, McCollum GW, Jayagopal A, Penn JS. High Glucose-induced Retinal Pericyte Apoptosis Depends on Association of GAPDH and Siah1. J Biol Chem 2015; 290:28311-28320. [PMID: 26438826 DOI: 10.1074/jbc.m115.682385] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Indexed: 11/06/2022] Open
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness worldwide, and its prevalence is growing. Current therapies for DR address only the later stages of the disease, are invasive, and have limited effectiveness. Retinal pericyte death is an early pathologic feature of DR. Although it has been observed in diabetic patients and in animal models of DR, the cause of pericyte death remains unknown. A novel pro-apoptotic pathway initiated by the interaction between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the E3 ubiquitin ligase, seven in absentia homolog 1 (Siah1), was recently identified in ocular tissues. In this article we examined the involvement of the GAPDH/Siah1 interaction in human retinal pericyte (hRP) apoptosis. HRP were cultured in 5 mm normal glucose, 25 mm l- or d-glucose for 48 h (osmotic control and high glucose treatments, respectively). Siah1 siRNA was used to down-regulate Siah1 expression. TAT-FLAG GAPDH and/or Siah1-directed peptides were used to block GAPDH and Siah1 interaction. Co-immunoprecipitation assays were conducted to analyze the effect of high glucose on the association of GAPDH and Siah1. Apoptosis was measured by Annexin V staining and caspase-3 enzymatic activity assay. High glucose increased Siah1 total protein levels, induced the association between GAPDH and Siah1, and led to GAPDH nuclear translocation. Our findings demonstrate that dissociation of the GAPDH/Siah1 pro-apoptotic complex can block high glucose-induced pericyte apoptosis, widely considered a hallmark feature of DR. Thus, the work presented in this article can provide a foundation to identify novel targets for early treatment of DR.
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Affiliation(s)
- Sandra Suarez
- Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8808.
| | - Gary W McCollum
- Departments of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8808
| | - Ashwath Jayagopal
- Pharma Research and Early Development (pRED), F. Hoffman-La Roche Ltd., Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | - John S Penn
- Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8808; Departments of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8808
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Interactions Between MPTP-Induced and Age-Related Neuronal Death in a Murine Model of Parkinson’s Disease. Can J Neurol Sci 2015. [DOI: 10.1017/s0317167100041494] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
ABSTRACT:Abiotrophy is hypothesized to explain the onset and time course of deficits in Parkinson’s disease (PD) Abiotrophy includes: 1) exposure to agent(s) causing the death of dopaminergic nigrostriatal neurons (DNSns), 2) gradual death of DNSns with age, 3) summation of 1) and 2) until DNSn numbers fall below a threshold for detectable neurological deficits. Murine DNSn death following methyl-phenyl-tetrahydropyridine (MPTP) exposure occurs according to an exponential relationship while age-related death of DNSns occurs according to a second exponential relationship. Summing the two exponential losses overestimates experimental DNSn death showing a simple abiotrophic model is not sufficient. Aged murine DNSns greatly increase their dopamine synthesis and the density of their striatal axon terminals which may explain the above threshold. Murine DNSns die gradually after MPTP exposure and L-deprenyl treatment rescues MPTP-damaged DNSns by a previously undiscovered action, altering the abiotrophic interactions and possibly explaining the slowed progression of PD found with deprenyl treatment.
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Wang Y, Hilton BA, Cui K, Zhu MY. Effects of Antidepressants on DSP4/CPT-Induced DNA Damage Response in Neuroblastoma SH-SY5Y Cells. Neurotox Res 2015; 28:154-70. [PMID: 26038195 DOI: 10.1007/s12640-015-9534-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 12/16/2022]
Abstract
DNA damage is a form of cell stress and injury. Increased systemic DNA damage is related to the pathogenic development of neurodegenerative diseases. Depression occurs in a relatively high percentage of patients suffering from degenerative diseases, for whom antidepressants are often used to relieve depressive symptoms. However, few studies have attempted to elucidate why different groups of antidepressants have similar effects on relieving symptoms of depression. Previously, we demonstrated that neurotoxins N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4)- and camptothecin (CPT) induced the DNA damage response in SH-SY5Y cells, and DSP4 caused cell cycle arrest which was predominately in the S-phase. The present study shows that CPT treatment also resulted in similar cell cycle arrest. Some classic antidepressants could reduce the DNA damage response induced by DSP4 or CPT in SH-SY5Y cells. Cell viability examination demonstrated that both DSP4 and CPT caused cell death, which was prevented by spontaneous administration of some tested antidepressants. Flow cytometric analysis demonstrated that a majority of the tested antidepressants protect cells from being arrested in S-phase. These results suggest that blocking the DNA damage response may be an important pharmacologic characteristic of antidepressants. Exploring the underlying mechanisms may allow for advances in the effort to improve therapeutic strategies for depression appearing in degenerative and psychiatric diseases.
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Affiliation(s)
- Yan Wang
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, 37604, USA
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Meredith GE, Rademacher DJ. MPTP mouse models of Parkinson's disease: an update. JOURNAL OF PARKINSONS DISEASE 2014; 1:19-33. [PMID: 23275799 DOI: 10.3233/jpd-2011-11023] [Citation(s) in RCA: 288] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Among the most widely used models of Parkinson's disease (PD) are those that employ toxins, especially 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Depending on the protocol used, MPTP yields large variations in nigral cell loss, striatal dopamine loss and behavioral deficits. Motor deficits do not fully replicate those seen in PD. Nonetheless, MPTP mouse models mimic many aspects of the disease and are therefore important tools for understanding PD. In this review, we will discuss the ability of MPTP mouse models to replicate the pathophysiology of PD, the mechanisms of MPTP-induced neurotoxicity, strain differences in susceptibility to MPTP, and the models' roles in testing therapeutic approaches.
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Affiliation(s)
- Gloria E Meredith
- Department of Pharmaceutical Sciences, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA.
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17
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Abstract
Monoamine oxidase inhibitors have been available for more than 50 years, initially developed as antidepressants but currently used in a variety of psychiatric and neurological conditions. There has been a recent surge of interest in monoamine oxidase inhibitors because of their reported neuroprotective and/or neurorescue properties. Interestingly, it seems that often these properties are independent of their ability to inhibit monoamine oxidase. This review article presents an overview of the neuroprotective/neurorescue properties of these multifaceted drugs and focuses on phenelzine, (-)-deprenyl, rasagiline, ladostigil, tranylcypromine, moclobemide, and clorgyline and their possible neuroprotective mechanisms.
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18
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Abstract
Selegiline at the doses used in Parkinson disease is a selective irreversible monoamine oxidase type B inhibitor, which potentiates dopaminergic function in the brain, and is used as monotherapy in early Parkinson disease or in combination with levodopa in more advanced disease. A renewed interest in monoamine oxidase type B inhibitors in the treatment of Parkinson disease has emerged after recent clinical trials of agents in this class. The use of selegiline monotherapy in early Parkinson disease is supported by the results of a large well-controlled trial in 800 patients (DATATOP) and several other studies, which demonstrated a symptomatic benefit, a reduction in disability, and a delay in the need to start levodopa therapy. Administered with levodopa in studies of up to 5 years' duration in patients with more advanced disease, selegiline improved disease-related disability, reduced the end-of-dose motor fluctuations, and also led to a reduction of the dose and dose frequency of levodopa required.Selegiline was the first drug to be investigated as a possible neuroprotective agent in patients with Parkinson disease, based on preclinical studies indicating protection of dopaminergic neurons from damage. The results of the extensive body of clinical trials, including delayed and lower levodopa requirements, may indeed suggest that selegiline, in addition to conferring symptomatic benefit, may have other effects on disease progression. Selegiline is well tolerated, and initial fears of increased mortality with the drug have not been borne out by subsequent robust meta-analyses.
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Gerlach M, Reichmann H, Riederer P. A critical review of evidence for preclinical differences between rasagiline and selegiline. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.baga.2012.04.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Foley P, Gerlach M, Youdim MB, Riederer P. MAO-B inhibitors: multiple roles in the therapy of neurodegenerative disorders? Parkinsonism Relat Disord 2012; 6:25-47. [PMID: 18591148 DOI: 10.1016/s1353-8020(99)00043-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/1998] [Revised: 06/29/1999] [Accepted: 06/29/1999] [Indexed: 11/16/2022]
Abstract
Monoamine oxidases play a central role in catecholamine catabolism in the central nervous system. The biochemical and pharmacological properties of inhibitors of the monoamine oxidase type B are reviewed. The evidence for biochemical activities distinct from their ability to inhibit MAO-B is discussed, including possible antioxidative and antiapoptotic activities of these agents. The significance of these properties for the pharmacological management of Parkinson's disease and the evidence for a neuroprotective effect of one such agent (selegiline) is also discussed.
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Affiliation(s)
- P Foley
- Clinical Neurochemistry, Department of Psychiatry, University of Würzburg, D-97080 Würzburg, Germany
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21
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Abstract
SIGNIFICANCE Several genetic causes of familial Parkinson's disease (PD) have now been identified and include mutations of genes encoding mitochondrial proteins. Mitochondrial complex I toxins can induce dopaminergic cell death and produce a parkinsonian state. Importantly, defects of mitochondrial function have been identified in postmortem substantia nigra from pathologically proven cases of PD. RECENT ADVANCES These observations provide compelling evidence to support the notion that mitochondria play an important role in the pathogenesis of PD. Thus, targeting mitochondrial function to delay or prevent neuronal cell death would represent a logical means to modify the course of this disease. Several attempts have already been made in this respect, and have been tested in clinical trial. CRITICAL ISSUES To date, there is no unequivocal evidence for an effective intervention to slow the disease. However, several novel mitochondrial targets are now emerging, including the potential to manipulate the mitochondrial pool to maintain function via biogenesis and mitophagy. FUTURE DIRECTIONS This development in drug targets needs to be supported by a parallel improvement in clinical trial design to be able to detect a neuroprotective or disease-modifying effect over a reasonable time scale.
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Koob AO, Bruns L, Prassler C, Masliah E, Klopstock T, Bender A. Protein analysis through Western blot of cells excised individually from human brain and muscle tissue. Anal Biochem 2012; 425:120-4. [PMID: 22402104 DOI: 10.1016/j.ab.2012.02.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 11/17/2022]
Abstract
Comparing protein levels from single cells in tissue has not been achieved through Western blot. Laser capture microdissection allows for the ability to excise single cells from sectioned tissue and compile an aggregate of cells in lysis buffer. In this study we analyzed proteins from cells excised individually from brain and muscle tissue through Western blot. After we excised individual neurons from the substantia nigra of the brain, the accumulated surface area of the individual cells was 120,000, 24,000, 360,000, 480,000, 600,000 μm2. We used an optimized Western blot protocol to probe for tyrosine hydroxylase in this cell pool. We also took 360,000 μm2 of astrocytes (1700 cells) and analyzed the specificity of the method. In muscle we were able to analyze the proteins of the five complexes of the electron transport chain through Western blot from 200 human cells. With this method, we demonstrate the ability to compare cell-specific protein levels in the brain and muscle and describe for the first time how to visualize proteins through Western blot from cells captured individually.
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Affiliation(s)
- A O Koob
- Department of Neurology, Klinikum Grosshadern, University of Munich, Marchinionistr. 23, 81377 Munich, Germany.
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23
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Schapira AHV. Monoamine oxidase B inhibitors for the treatment of Parkinson's disease: a review of symptomatic and potential disease-modifying effects. CNS Drugs 2011; 25:1061-71. [PMID: 22133327 DOI: 10.2165/11596310-000000000-00000] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Parkinson's disease is a disorder characterized pathologically by progressive neurodegeneration of the dopaminergic cells of the nigrostriatal pathway. Although the resulting dopamine deficiency is the cause of the typical motor features of Parkinson's disease (bradykinesia, rigidity, tremor), additional non-motor symptoms appear at various timepoints and are the result of non-dopamine nerve degeneration. Monoamine oxidase B (MAO-B) inhibitors are used in the symptomatic treatment of Parkinson's disease as they increase synaptic dopamine by blocking its degradation. Two MAO-B inhibitors, selegiline and rasagiline, are currently licensed in Europe and North America for the symptomatic improvement of early Parkinson's disease and to reduce off-time in patients with more advanced Parkinson's disease and motor fluctuations related to levodopa. A third MAO-B inhibitor (safinamide), which also combines additional non-dopaminergic properties of potential benefit to Parkinson's disease, is currently under development in phase III clinical trials as adjuvant therapy to either a dopamine agonist or levodopa. MAO-B inhibitors have also been studied extensively for possible neuroprotective or disease-modifying actions. There is considerable laboratory evidence that MAO-B inhibitors do exert some neuroprotective properties, at least in the Parkinson's disease models currently available. However, these models have significant limitations and caution is required in assuming that such results may easily be extrapolated to clinical trials. Rasagiline 1 mg/day has been shown to provide improved motor control in terms of Unified Parkinson's Disease Rating Scale (UPDRS) score at 18 months in those patients with early disease who began the drug 9 months before a second group. There are a number of possible explanations for this effect that may include a disease-modifying action; however, the US FDA recently declined an application for the licence of rasagiline to be extended to cover disease modification.
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The anti-Parkinsonian drug selegiline delays the nucleation phase of α-synuclein aggregation leading to the formation of nontoxic species. J Mol Biol 2010; 405:254-73. [PMID: 21050861 DOI: 10.1016/j.jmb.2010.10.027] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 08/28/2010] [Accepted: 10/16/2010] [Indexed: 11/22/2022]
Abstract
Parkinson's disease (PD) is a movement disorder characterized by the loss of dopaminergic neurons in the substantia nigra and the formation of intraneuronal inclusions called Lewy bodies, which are composed mainly of α-synuclein (α-syn). Selegiline (Sel) is a noncompetitive monoamino oxidase B inhibitor that has neuroprotective effects and has been administered to PD patients as monotherapy or in combination with l-dopa. Besides its known effect of increasing the level of dopamine (DA) by monoamino oxidase B inhibition, Sel induces other effects that contribute to its action against PD. We evaluated the effects of Sel on the in vitro aggregation of A30P and wild-type α-syn. Sel delays fibril formation by extending the lag phase of aggregation. In the presence of Sel, electron microscopy reveals amorphous heterogeneous aggregates, including large annular species, which are innocuous to a primary culture enriched in dopaminergic neurons, while their age-matched counterparts are toxic. The inhibitory effect displayed by Sel is abolished when seeds (small fibril pieces) are added to the aggregation reaction, reinforcing the hypothesis that Sel interferes with early nuclei formation and, to a lesser extent, with fibril elongation. NMR experiments indicate that Sel does not interact with monomeric α-syn. Interestingly, when added in combination with DA (which favors the formation of toxic protofibrils), Sel overrides the inhibitory effect of DA and favors fibrillation. Additionally, Sel blocks the formation of smaller toxic aggregates by perturbing DA-dependent fibril disaggregation. These effects might be beneficial for PD patients, since the sequestration of protofibrils into fibrils or the inhibition of fibril dissociation could alleviate the toxic effects of protofibrils on dopaminergic neurons. In nondopaminergic neurons, Sel might slow the fibrillation, giving rise to the formation of large nontoxic aggregates.
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Leegwater-Kim J, Bortan E. The role of rasagiline in the treatment of Parkinson's disease. Clin Interv Aging 2010; 5:149-56. [PMID: 20517484 PMCID: PMC2877525 DOI: 10.2147/cia.s4145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Indexed: 01/07/2023] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting 1% to 2% of people older than 60 years. Treatment of PD consists of symptomatic therapies while neuroprotective strategies have remained elusive. Rasagiline is a novel, potent, and irreversible monoamine oxidase type B (MAO-B) inhibitor which has been approved for treatment of PD. Rasagiline inhibits MAO-B more potently than selegiline and has the advantage of once-daily dosing. In several large, randomized, placebo-controlled trials, rasagiline has demonstrated efficacy as monotherapy in early PD and as adjunctive therapy in advanced PD. In addition, rasagiline has been shown to have neuroprotective effects in in vitro and in vivo studies. The recently completed delayed-start ADAGIO (Attenuation of Disease Progression with Azilect Given Once-daily) trial suggests a potential disease-modifying effect for rasagiline 1 mg/day, though the clinical import of this finding has yet to be established.
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Affiliation(s)
- Julie Leegwater-Kim
- Department of Neurology, Tufts University School of Medicine, Lahey Clinic, Burlington, MA 01805, USA.
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26
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Hazleton JE, Berman JW, Eugenin EA. Novel mechanisms of central nervous system damage in HIV infection. HIV AIDS-RESEARCH AND PALLIATIVE CARE 2010; 2:39-49. [PMID: 22096383 PMCID: PMC3218694 DOI: 10.2147/hiv.s9186] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human immunodeficiency virus-1 infection of the central nervous system is an early event after primary infection, resulting in motor and cognitive defects in a significant number of individuals despite successful antiretroviral therapy. The pathology of the infected brain is characterized by enhanced leukocyte infiltration, microglial activation and nodules, aberrant expression of inflammatory factors, neuronal dysregulation and loss, and blood–brain barrier disruption. Months to years following the primary infection, these central nervous system insults result in a spectrum of motor and cognitive dysfunction, ranging from mild impairment to frank dementia. The mechanisms that mediate impairment are still not fully defined. In this review we discuss the cellular and molecular mechanisms that facilitate impairment and new data that implicate intercellular communication systems, gap junctions and tunneling nanotubes, as mediators of human immunodeficiency virus-1 toxicity and infection within the central nervous system. These data suggest potential targets for novel therapeutics.
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Affiliation(s)
- Joy E Hazleton
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
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Fernandes A, de Oliveira EF, de Rezende ICV, Ponzoni S. Manganese neurotoxic time course is not influenced by l-deprenyl systemic treatment. Brain Res 2010; 1317:277-85. [DOI: 10.1016/j.brainres.2009.12.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2009] [Revised: 12/20/2009] [Accepted: 12/21/2009] [Indexed: 11/26/2022]
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28
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Schifitto G, Yiannoutsos CT, Ernst T, Navia BA, Nath A, Sacktor N, Anderson C, Marra CM, Clifford DB. Selegiline and oxidative stress in HIV-associated cognitive impairment. Neurology 2009; 73:1975-81. [PMID: 19890073 DOI: 10.1212/wnl.0b013e3181c51a48] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE To assess the effectiveness of the selegiline transdermal system (STS) in reversing HIV-induced metabolic brain injury (as measured by proton magnetic resonance spectroscopy [MRS]) and in decreasing oxidative stress, measured by CSF protein carbonyl concentration. METHODS Sixty-two subjects with HIV-associated cognitive impairment were coenrolled in a 24-week placebo-controlled study (AIDS Clinical Trial Group protocol A5090) and were randomly assigned to receive STS 3 mg/24 h, STS 6 mg/24 h, or matching placebo. Cognitive performance was evaluated using the neuropsychological z score (NPZ)-8 and NPZ-6, as well as cognitive domain scores. Subjects underwent proton MRS at study entry and weeks 12 and 24. CSF protein carbonyl was measured at baseline and week 24. RESULTS A slight increase in N-acetyl aspartate/creatine from baseline to week 24 was found in the basal ganglia (p = 0.023) and centrum semiovale (p = 0.072) of the placebo group compared with the STS groups; however, there were no significant changes when the absolute metabolite concentrations were analyzed. The levels of choline/creatine in the midfrontal cortex were also significantly higher during the week 12 visit in the combined STS groups. This persisted to the week 24 visit (p = 0.002). Evaluation of the change in NPZ-8, NPZ-6, and cognitive domain scores from baseline to weeks 12 and 24 revealed no significant differences between treatment arms. Protein carbonyl analysis revealed no significant changes among the groups. CONCLUSION In this 24-week study, the selegiline transdermal system (STS) had no effect on either magnetic resonance spectroscopy (MRS) metabolites or oxidative stress, as measured by CSF protein carbonyl concentration. The lack of effect on these biomarkers is also reflected in the lack of cognitive improvement in the STS groups compared to placebo. LEVEL OF EVIDENCE This study provides Class II evidence that STS had no effect on either MRS metabolites or oxidative stress, as measured by CSF protein carbonyl concentration over a period of 24 weeks.
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Saavedra A, Baltazar G, Duarte EP. Driving GDNF expression: the green and the red traffic lights. Prog Neurobiol 2008; 86:186-215. [PMID: 18824211 DOI: 10.1016/j.pneurobio.2008.09.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 06/18/2008] [Accepted: 09/03/2008] [Indexed: 01/28/2023]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is widely recognized as a potent survival factor for dopaminergic neurons of the nigrostriatal pathway that degenerate in Parkinson's disease (PD). In animal models of PD, GDNF delivery to the striatum or the substantia nigra protects dopaminergic neurons against subsequent toxin-induced injury and rescues previously damaged neurons, promoting recovery of the motor function. Thus, GDNF was proposed as a potential therapy to PD aimed at slowing down, halting or reversing neurodegeneration, an issue addressed in previous reviews. However, the use of GDNF as a therapeutic agent for PD is hampered by the difficulty in delivering it to the brain. Another potential strategy is to stimulate the endogenous expression of GDNF, but in order to do that we need to understand how GDNF expression is regulated. The aim of this review is to do a comprehensive analysis of the state of the art on the control of endogenous GDNF expression in the nervous system, focusing mainly on the nigrostriatal pathway. We address the control of GDNF expression during development, in the adult brain and after injury, and how damaged neurons signal glial cells to up-regulate GDNF. Pharmacological agents or natural molecules that increase GDNF expression and show neuroprotective activity in animal models of PD are reviewed. We also provide an integrated overview of the signalling pathways linking receptors for these molecules to the induction of GDNF gene, which might also become targets for neuroprotective therapies in PD.
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Affiliation(s)
- Ana Saavedra
- Department of Cell Biology, Immunology and Neurosciences, Faculty of Medicine, University of Barcelona, Carrer Casanova 143, 08036 Barcelona, Spain.
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Chetsawang B, Kooncumchoo P, Govitrapong P, Ebadi M. 1-Methyl-4-phenyl-pyridinium ion-induced oxidative stress, c-Jun phosphorylation and DNA fragmentation factor-45 cleavage in SK-N-SH cells are averted by selegiline. Neurochem Int 2008; 53:283-8. [PMID: 18805449 DOI: 10.1016/j.neuint.2008.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 08/05/2008] [Accepted: 08/18/2008] [Indexed: 10/21/2022]
Abstract
Parkinson's disease is a progressive neurodegenerative disorder, associated with the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Recent studies have shown that c-Jun-N terminal kinase pathways might be involved in the oxidative stress-induced neuronal demise. In addition, there are several studies demonstrating that selegiline protects neural cell degeneration. In view of the above, the toxic effects of MPP(+) and the protective roles of selegiline were studied in cultures of human neuroblastoma (SK-N-SH) cell lines in the present study. MPP(+) significantly decreased cell viability but increased reactive oxygen species formation and lipid peroxidation, and the said effects were attenuated by selegiline. MPP(+) did not change the total levels of c-Jun but enhanced phosphorylation of c-Jun at Ser73 and cleavage of DNA fragmentation factor 45, which were diminished by selegiline. MPP(+)-treated SK-N-SH cells exhibited an irregularly shaped nuclear chromatin or DNA fragmentation, which was abolished by selegiline. These data suggest that c-Jun-N terminal kinase pathways are involved in oxidative stress-induced dopaminergic neuronal degeneration and pretreatment with selegiline affords neuroprotection by inhibiting these cell death-signaling pathways.
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Affiliation(s)
- Banthit Chetsawang
- Institute of Science and Technology for Research and Development, Mahidol University, Salaya, Nakhonpathom 73170, Thailand.
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Neural progenitor cells are protected against MPTP by MAO-B inhibitors. Neurotoxicology 2008; 29:1141-6. [PMID: 18606181 DOI: 10.1016/j.neuro.2008.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 04/22/2008] [Accepted: 05/16/2008] [Indexed: 11/21/2022]
Abstract
Neurotoxic effects of MPTP on the nigrostriatal dopaminergic system are thought to be initiated by 1-methyl-4-phenylpyridinium (MPP+), a metabolite formed by the monoamine oxidase (MAO)-B-mediated oxidation of MPTP. We previously reported that the administration of MPTP induced apoptosis in migrating neuroblasts (neural progenitor cells, NPCs) in adult mice. To determine whether MAO-B is also involved in the neurotoxicity of MPTP to NPCs, this study looked at the effects of MAO B inhibitors, R(-)-deprenyl (deprenyl) and N-(2-aminoethyl)-4-chlorobenzamide (Ro 16-6491), both of which protect the dopaminergic system against MPTP. Few apoptotic cells were found in saline- or MAO-B inhibitor-treated animals but MPTP markedly induced apoptosis in the subventricular zone (SVZ) and rostral migratory stream (RMS) after 1 day. When mice were pretreated with deprenyl or Ro 16-6491, not only nigrostriatal dopamine levels but also NPCs were significantly protected against MPTP. In addition, MPTP-induced apoptosis was found in both juvenile (postnatal 21 days) and older (12 months old) mice, suggesting NPCs to be different from the dopamine system, which has been thought to exhibit age-dependent susceptibility to MPTP.
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Abstract
Slowing or aborting the progress of neurodegeneration in Parkinson's disease (PD) remains the most important unmet need of this disorder. There are several recent developments in trial design and also in drugs under investigation for possible neuroprotective effect. Emphasis has been placed on clinical as opposed to imaging end-points and these include change in a clinical rating scale, e.g. United Parkinson's disease Rating Scale (UPDRS), or time to additional therapy. The introduction of the delayed-start, or wash-in, trial design adds an additional dimension to drug evaluation for neuroprotection. Compounds that have been recently tested in clinical trial include the monoamine oxidase-B inhibitor rasagiline, the anti-apoptotic agents TCH346 and CEP1347, and the promitochondrial agent creatine. The dopamine agonists have been evaluated for a neuroprotective effect using imaging end-points. Perhaps the most important and simplest concept for neuroprotection has been the theory that early dopaminergic support for the degenerating dopaminergic system per se provides significant long-term clinical benefit for PD patients.
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Affiliation(s)
- A H V Schapira
- University Department of Clinical Neurosciences, Institute of Neurology, University College London, London, UK.
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Schapira AHV. Future directions in the treatment of Parkinson's disease. Mov Disord 2007; 22 Suppl 17:S385-91. [PMID: 18175401 DOI: 10.1002/mds.21679] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Anthony H V Schapira
- University Department of Clinical Neurosciences, Royal Free and University College Medical School, University College London, London, UK.
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Schapira AHV, Bezard E, Brotchie J, Calon F, Collingridge GL, Ferger B, Hengerer B, Hirsch E, Jenner P, Le Novère N, Obeso JA, Schwarzschild MA, Spampinato U, Davidai G. Novel pharmacological targets for the treatment of Parkinson's disease. Nat Rev Drug Discov 2006; 5:845-54. [PMID: 17016425 DOI: 10.1038/nrd2087] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dopamine deficiency, caused by the degeneration of nigrostriatal dopaminergic neurons, is the cause of the major clinical motor symptoms of Parkinson's disease. These symptoms can be treated successfully with a range of drugs that include levodopa, inhibitors of the enzymatic breakdown of levodopa and dopamine agonists delivered by oral, subcutaneous, transcutaneous, intravenous or intra-duodenal routes. However, Parkinson's disease involves degeneration of non-dopaminergic neurons and the treatment of the resulting predominantly non-motor features remains a challenge. This review describes the important recent advances that underlie the development of novel dopaminergic and non-dopaminergic drugs for Parkinson's disease, and also for the motor complications that arise from the use of existing therapies.
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Affiliation(s)
- Anthony H V Schapira
- University Department of Clinical Neurosciences, Royal Free and University College Medical School, University College London, Rowland Hill Street, London NW3 2PF, UK.
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Rubinstein S, Malone MA, Roberts W, Logan WJ. Placebo-controlled study examining effects of selegiline in children with attention-deficit/hyperactivity disorder. J Child Adolesc Psychopharmacol 2006; 16:404-15. [PMID: 16958566 DOI: 10.1089/cap.2006.16.404] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
There is evidence suggesting a role for dopamine in attention-deficit/hyperactivity disorder (ADHD). Pharmacological treatments that act on the dopamine system have been successful in reducing ADHD symptoms. However, unlike traditional stimulants (i.e., methylphenidate), selegiline is a monoamine oxidase inhibitor (MAOI) that has been shown to reduce ADHD symptoms without producing undesirable side effects. In this study using a randomized, double- blind, placebo-controlled, crossover design, cognitive tasks and behavioral rating scales were administered to measure the effectiveness of selegiline in treating different symptoms of ADHD in 11 children aged 6-13. Results indicate that selegiline may target specific symptoms of ADHD including: sustained attention, the learning of novel information, hyperactivity, and peer interactions. Because the drug was not associated with negative side effects and did not specifically reduce symptoms of impulsivity, selegiline may be a preferred treatment for individuals who present with the primarily inattentive subtype of ADHD.
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Affiliation(s)
- Suzanne Rubinstein
- Division of Neurology, Brain and Behaviour Programme, The Hospital for Sick Children, Toronto, Ontario, Canada
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Berry MD. R-2HMP: an Orally Active Agent Combining Independent Antiapoptotic and MAO-B-Inhibitory Activities. CNS DRUG REVIEWS 2006. [DOI: 10.1111/j.1527-3458.1999.tb00093.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Youdim MBH, Edmondson D, Tipton KF. The therapeutic potential of monoamine oxidase inhibitors. Nat Rev Neurosci 2006; 7:295-309. [PMID: 16552415 DOI: 10.1038/nrn1883] [Citation(s) in RCA: 946] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Monoamine oxidase inhibitors were among the first antidepressants to be discovered and have long been used as such. It now seems that many of these agents might have therapeutic value in several common neurodegenerative conditions, independently of their inhibition of monoamine oxidase activity. However, many claims and some counter-claims have been made about the physiological importance of these enzymes and the potential of their inhibitors. We evaluate these arguments in the light of what we know, and still have to learn, of the structure, function and genetics of the monoamine oxidases and the disparate actions of their inhibitors.
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Affiliation(s)
- Moussa B H Youdim
- Technion-Rappaport Family Faculty of Medicine, Eve Topf and US National Parkinson Foundation Centers of Excellence for Neurodegenerative Diseases.
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Hara MR, Thomas B, Cascio MB, Bae BI, Hester LD, Dawson VL, Dawson TM, Sawa A, Snyder SH. Neuroprotection by pharmacologic blockade of the GAPDH death cascade. Proc Natl Acad Sci U S A 2006; 103:3887-9. [PMID: 16505364 PMCID: PMC1450161 DOI: 10.1073/pnas.0511321103] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) participates in a cell death cascade wherein a variety of stimuli activate nitric oxide (NO) synthases with NO nitrosylating GAPDH, conferring on it the ability to bind to Siah, an E3-ubiquitin-ligase, whose nuclear localization signal enables the GAPDH/Siah protein complex to translocate to the nucleus where degradation of Siah targets elicits cell death. R-(-)-Deprenyl (deprenyl) ameliorates the progression of disability in early Parkinson's disease and also has neuroprotective actions. We show that deprenyl and a related agent, TCH346, in subnanomolar concentrations, prevent S-nitrosylation of GAPDH, the binding of GAPDH to Siah, and nuclear translocation of GAPDH. In mice treated with the dopamine neuronal toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), low doses of deprenyl prevent binding of GAPDH and Siah1 in the dopamine-enriched corpus striatum.
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Affiliation(s)
- Makoto R. Hara
- Departments of *Neuroscience
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Bobby Thomas
- Department of Neurology and Institute for Cell Engineering, and
| | | | | | | | - Valina L. Dawson
- Departments of *Neuroscience
- Department of Neurology and Institute for Cell Engineering, and
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Ted M. Dawson
- Departments of *Neuroscience
- Department of Neurology and Institute for Cell Engineering, and
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Akira Sawa
- Departments of *Neuroscience
- Psychiatry, and
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Solomon H. Snyder
- Departments of *Neuroscience
- Psychiatry, and
- Pharmacology
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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Vlok N, Malan SF, Castagnoli N, Bergh JJ, Petzer JP. Inhibition of monoamine oxidase B by analogues of the adenosine A2A receptor antagonist (E)-8-(3-chlorostyryl)caffeine (CSC). Bioorg Med Chem 2006; 14:3512-21. [PMID: 16442801 DOI: 10.1016/j.bmc.2006.01.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2005] [Revised: 01/05/2006] [Accepted: 01/05/2006] [Indexed: 10/25/2022]
Abstract
The adenosine A2A receptor has emerged as a possible target for the treatment of Parkinson's disease (PD). Evidence suggests that antagonism of the A2A receptor not only improves the symptoms of the disease but may also protect against the underlying degenerative processes. We have recently reported that several known adenosine A2A receptor antagonists (A2A antagonists) also are moderate to very potent inhibitors of monoamine oxidase B (MAO-B). The most potent among these was (E)-8-(3-chlorostyryl)caffeine (CSC), a compound frequently used when examining the in vivo pharmacological effects of A2A antagonists. Since MAO-B inhibitors are also thought to possess antiparkinsonian properties, dual targeting drugs that block both MAO-B and A2A receptors may have enhanced therapeutic potential in the treatment of PD. In this study, we prepared selected analogues of CSC in an attempt to examine specific structural features that may be important for potent MAO-B inhibition. The results of a SAR study established that the potency of MAO-B inhibition by (E)-8-styrylcaffeinyl analogues depends upon the van der Waals volume (V(w)), lipophilicity (pi), and the Hammett constant (sigma(m)) of the substituents attached to C-3 of the phenyl ring of the styryl moiety. Potency also varies with substituents attached to C-4 with bulkiness (V(w)) and lipophilicity (pi) being the principal substituent descriptors.
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Affiliation(s)
- Nevil Vlok
- Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
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Pan C, Liu F, Ji Q, Wang W, Drinkwater D, Vivilecchia R. The use of LC/MS, GC/MS, and LC/NMR hyphenated techniques to identify a drug degradation product in pharmaceutical development. J Pharm Biomed Anal 2005; 40:581-90. [PMID: 16242883 DOI: 10.1016/j.jpba.2005.08.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 07/29/2005] [Accepted: 08/04/2005] [Indexed: 10/25/2022]
Abstract
Understanding drug degradation in the formulated product is critical in pharmaceutical development as it has significant impacts on drug efficacy, safety profile and storage conditions. As a result, identification of degradation compounds has taken an important role in the drug development process. In this study, various hyphenated analytical techniques, such as liquid chromatography mass spectrometry (LC/MS), gas chromatography mass spectrometry (GC/MS), and liquid chromatography nuclear magnetic resonance with a solid phase extraction interface (LC/SPE/NMR), have been applied to the identification of a drug degradation product which grew over time in the stability study of the drug product. The target unknown is less polar and more unsaturated than the drug substance based upon reverse phase HPLC relative retention time and UV spectra. It is not ionizable by electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) in either a positive or a negative mode. The unknown was isolated by an HPLC fraction collector and enriched by solid phase extraction. GC/MS with chemical ionization (CI) was employed to determine the molecular weight of this compound. Its fragmentation pattern was determined by CI-MS/MS using an ion trap mass spectrometer. The isolated material was also analyzed by LC/SPE/NMR, from which the structure of this compound was further characterized. The study utilizes a combination of various hyphenated analytical techniques to obtain complimentary information for structure elucidation of the unknown. The combination approach is critical for unambiguous impurity structure elucidation in drug degradation studies of pharmaceutical drug products.
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Affiliation(s)
- Changkang Pan
- Pharmaceutical and Analytical Development, Novartis Pharmaceuticals Corporation, One Health Plaza, East Hanover, NJ 07936, USA.
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Yasar S, Gaal J, Justinova Z, Bergman J. Discriminative stimulus and reinforcing effects of p-fluoro-L-deprenyl in monkeys. Psychopharmacology (Berl) 2005; 182:95-103. [PMID: 15990999 DOI: 10.1007/s00213-005-0063-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Accepted: 05/02/2005] [Indexed: 11/25/2022]
Abstract
RATIONALE para-Fluoro-L-deprenyl (Fludepryl), a halogenated derivative of L-deprenyl, shares structural similarities with amphetamine and may have potential as a medication for psychostimulant abuse. OBJECTIVES p-Fluoro-L-deprenyl was evaluated for psychomotor stimulant, discriminative stimulus, and reinforcing effects in squirrel monkeys. METHODS One group of monkeys was trained under a ten-response fixed-ratio (FR10) schedule of stimulus termination to discriminate between methamphetamine (0.32 mg/kg, i.m.) and saline. Other monkeys were trained to self-administer i.v. cocaine under either a simple FR10 schedule or a second-order fixed-interval 5-min schedule with FR10 components. RESULTS Full generalization to the methamphetamine-training stimulus was produced by an i.m. dose of 10.0 mg/kg p-fluoro-L-deprenyl. L-Deprenyl and the metabolites of p-fluoro-L-deprenyl, p-fluoro-L-amphetamine, and p-fluoro-L-methylamphetamine were more potent, producing full generalization at doses of 1.0-3.2 mg/kg. Under the FR10 schedule of drug injection, persistent self-administration behavior was maintained by i.v. cocaine injections but not by injections of vehicle or injection doses of p-fluoro-L-deprenyl up to 1.0 mg/kg. However, p-fluoro-L-deprenyl did maintain moderate levels of i.v. self-administration responding under the second-order schedule of drug injection. Peak response rates maintained by 0.1-mg/kg injections of p-fluoro-L-deprenyl were significantly greater than those associated with saline substitution, yet significantly lower than those maintained by cocaine or D-amphetamine. CONCLUSIONS p-Fluoro-L-deprenyl has methamphetamine-like discriminative-stimulus properties in squirrel monkeys that appear at higher doses than for its parent compound, L-deprenyl. It also appears to function as a relatively limited reinforcer of intravenous self-administration behavior in monkeys trained to self-administer i.v. cocaine.
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Affiliation(s)
- Sevil Yasar
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
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Joyce JN, Woolsey C, Ryoo H, Borwege S, Hagner D. Low dose pramipexole is neuroprotective in the MPTP mouse model of Parkinson's disease, and downregulates the dopamine transporter via the D3 receptor. BMC Biol 2004; 2:22. [PMID: 15473914 PMCID: PMC524509 DOI: 10.1186/1741-7007-2-22] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Accepted: 10/11/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Our aim was to determine if pramipexole, a D3 preferring agonist, effectively reduced dopamine neuron and fiber loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model when given at intraperitoneal doses corresponding to clinical doses. We also determined whether subchronic treatment with pramipexole regulates dopamine transporter function, thereby reducing intracellular transport of the active metabolite of MPTP, 1-methyl-4-phenylpyridinium (MPP+). METHODS Ten 12-month old C57BL/6 mice were treated with MPTP (or saline) twice per day at 20 mg/kg s.c. (4 injections over 48 h). Mice were pretreated for 3 days and during the 2-day MPTP regimen with pramipexole (0.1 mg/kg/day) or saline. Stereological quantification of dopamine neuron number and optical density measurement of dopamine fiber loss were carried out at 1 week after treatment, using immunostaining for dopamine transporter (DAT) and tyrosine hydroxylase (TH). Additional wild-type (WT) and D3 receptor knockout (KO) mice were treated for 5 days with pramipexole (0.1 mg/kg/day) or vehicle. The kinetics of [3H]MPP+ and [3H]DA uptake (Vmax and Km) were determined 24 h later; and at 24 h and 14 days dopamine transporter density was measured by quantitative autoradiography. RESULTS Pramipexole treatment completely antagonized the neurotoxic effects of MPTP, as measured by substantia nigra and ventral tegmental area TH-immunoreactive cell counts. MPTP- induced loss of striatal innervation, as measured by DAT-immunoreactivity, was partially prevented by pramipexole, but not with regard to TH-IR. Pramipexole also reduced DAT- immunoreactivity in non-MPTP treated mice. Subchronic treatment with pramipexole lowered the Vmax for [3H]DA and [3H]MPP+ uptake into striatal synaptosomes of WT mice. Pramipexole treatment lowered Vmax in WT but not D3 KO mice; however, D3 KO mice had lower Vmax for [3H]DA uptake. There was no change in DAT number in WT with pramipexole treatment or D3 KO mice at 24 h post-treatment, but there was a reduction in WT-pramipexole treated and not in D3 KO mice at 14 days post-treatment. CONCLUSION These results suggest that protection occurs at clinically suitable doses of pramipexole. Protection could be due to a reduced amount of MPP+ taken up into DA terminals via DAT. D3 receptor plays an important role in this regulation of transporter uptake and availability.
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Affiliation(s)
- Jeffrey N Joyce
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Dr., Sun City, AZ, 85352, USA
| | - Cheryl Woolsey
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Dr., Sun City, AZ, 85352, USA
| | - Han Ryoo
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Dr., Sun City, AZ, 85352, USA
| | - Sabine Borwege
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Dr., Sun City, AZ, 85352, USA
| | - Diane Hagner
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Dr., Sun City, AZ, 85352, USA
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Kumar MJ, Andersen JK. Perspectives on MAO-B in aging and neurological disease: where do we go from here? Mol Neurobiol 2004; 30:77-89. [PMID: 15247489 DOI: 10.1385/mn:30:1:077] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Accepted: 01/02/2004] [Indexed: 11/11/2022]
Abstract
The catecholamine-oxidizing enzyme monoamine oxidase-B (MAO-B) has been hypothesized to be an important determining factor in the etiology of both normal aging and age-related neurological disorders such as Parkinson's disease (PD). Catalysis of substrate by the enzyme produces H2O2 which is a primary originator of oxidative stress which in turn can lead to cellular damage. MAO-B increases with age as does predisposition towards PD which has also been linked to increased oxidative stress. Inhibition of MAO-B, along with supplementation of lost dopamine via L-DOPA, is one of the major antiparkinsonian therapies currently in use. In this review, we address several factors contributing to a possible role for MAO-B in normal brain aging and neurological disease and also discuss the use of MAO-B inhibitors as drug therapy for these conditions.
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Seymour CB, Mothersill C, Mooney R, Moriarty M, Tipton KF. Monoamine oxidase inhibitors l-deprenyl and clorgyline protect nonmalignant human cells from ionising radiation and chemotherapy toxicity. Br J Cancer 2004; 89:1979-86. [PMID: 14612913 PMCID: PMC2394440 DOI: 10.1038/sj.bjc.6601361] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
l-Deprenyl (R-(−)-deprenyl, selegiline) is an inhibitor of monoamine oxidase-B (MAO-B) that is known to protect nerve cells from a variety of chemical and physical insults. As apoptosis is a common mechanism of radiation-induced cell death, the effect of l-deprenyl on the survival of cultured cells and tissue explants was studied following exposure to gamma radiation. The results obtained were compared with the effects of the less-selective MAO-B inhibitor pargyline and the MAO-A inhibitor clorgyline. l-Deprenyl at a concentration of 10−9 M protected the nontumorigenic cell line (HaCaT) and normal human urothelial explants from the effects of cobalt-60 gamma radiation, but did not protect tumorigenic human cell lines HaCaT-ras, HPV-transfected human keratinocytes (HPV-G cells), or PC3. Human bladder carcinoma explants were not protected. Clorgyline showed a smaller protective effect of normal cells, whereas pargyline had no effect. Radiation-induced delayed effects (genomic instability measured as delayed cell death) were prevented in normal cells by l-deprenyl but, interestingly, deprenyl appeared to increase the amount of delayed death in the tumorigenic cell lines. Studies using l-deprenyl prior to the exposure of nonmalignant cells to cisplatin showed that cell death due to this agent was also reduced. Treatment of cultures of nontumorigenic cells with l-deprenyl or clorgyline significantly increased the levels of the protein Bcl-2 following irradiation, but there was no such effect on the already-elevated levels of this protein in the tumour samples. Since the Bcl-2 has been shown to be an inhibitor of apoptosis or programmed cell death, this would imply that the protective effects of l-deprenyl and clorgyline involve activation of antiapoptotic pathways within the normal cell. This hypothesis is supported by data showing reduced levels of apoptosis in HaCAT cells and in normal bladder explant cultures following treatment with l-deprenyl.
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Affiliation(s)
- C B Seymour
- Radiation and Environmental Science Centre, Dublin Institute of Technology, Kevin St, Dublin 8, Ireland
- St Luke's Institute for Cancer Research, Rathgar, Dublin 6, Ireland
| | - C Mothersill
- Radiation and Environmental Science Centre, Dublin Institute of Technology, Kevin St, Dublin 8, Ireland
- St Luke's Institute for Cancer Research, Rathgar, Dublin 6, Ireland
- Dept Medical Physics & Applied Radiation Science, McMaster University, West Main Street, Hamilton Ontario, Canada, L8S 4K1. E-mail:
| | - R Mooney
- Radiation and Environmental Science Centre, Dublin Institute of Technology, Kevin St, Dublin 8, Ireland
| | - M Moriarty
- St Luke's Institute for Cancer Research, Rathgar, Dublin 6, Ireland
| | - K F Tipton
- Department of Biochemistry, Trinity College, Dublin 2, Ireland
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De Marchi U, Pietrangeli P, Marcocci L, Mondovì B, Toninello A. l-Deprenyl as an inhibitor of menadione-induced permeability transition in liver mitochondria. Biochem Pharmacol 2003; 66:1749-54. [PMID: 14563485 DOI: 10.1016/s0006-2952(03)00474-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
L-Deprenyl, an inhibitor of mitochondrial monoamine oxidase B (MAO B), inhibits the swelling of liver mitochondria induced by the pro-oxidant 2-methyl-1,4-naphtoquinone with a K(i) dependent on quinone concentration. L-Deprenyl also inhibits the collapse of membrane potential, cation efflux, pyridine nucleotide oxidation and cytochrome c release, all events which accompany the osmotic change and are typical of membrane permeability transition induction, thus emphasizing the inhibitory effect of the drug on this phenomenon. Results show that this inhibition is not due to the effect of L-deprenyl on monoamine oxidase activity but is most likely due to a direct interaction of the drug with the pore forming structures. It is here proposed that L-deprenyl, being a propargylamine, at physiological pH has a protonated amino group able to interact with critical aromatic or anionic amino acidic residues. As a consequence, the opening of the transition pore is prevented. These results indicate a more generalized protective effect of L-deprenyl on mitochondrial functions, involving the inhibition of membrane permeability transition induced not only by the oxidation of substrates of MAO B, but also by pro-oxidant agents such as 2-methyl-1,4-naphtoquinone, which does not involve MAO B activity.
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Affiliation(s)
- Umberto De Marchi
- Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Padua, Italy
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Joyce JN, Presgraves S, Renish L, Borwege S, Osredkar T, Hagner D, Replogle M, PazSoldan M, Millan MJ. Neuroprotective effects of the novel D3/D2 receptor agonist and antiparkinson agent, S32504, in vitro against 1-methyl-4-phenylpyridinium (MPP+) and in vivo against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): a comparison to ropinirole. Exp Neurol 2003; 184:393-407. [PMID: 14637109 DOI: 10.1016/s0014-4886(03)00353-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The novel naphtoxazine derivative and preferential D(3) vs D(2) receptor agonist, S32504, restores perturbed motor function in rodent and primate models of antiparkinsonian activity with a potency superior to those of two further, preferential D(3) receptor agonists, pramipexole and ropinirole. However, potential neuroprotective properties of S32054 have not, to date, been evaluated. Herein, employing several measures of cellular integrity, we demonstrate that S32504 robustly, concentration-dependently and completely protects terminally differentiated SH-SY5Y cells against 1-methyl-4-phenylpyridinium (MPP+)-induced cell death in vitro. Further, S32504 was substantially more potent than pramipexole and ropinirole, the latter of which was neurotoxic at high concentrations. In vivo, subchronic treatment with low (0.25 mg/kg) and high (2.5 mg/kg) doses of S32504 prior to and during treatment of mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, MPTP, provided complete protection against MPTP-induced tyrosine hydroxylase immunoreactive (TH-IR) neuronal death in the substantia nigra pars compacta and ventral tegmental area. A high dose of ropinirole (2.5 mg/kg) provided some protection but statistical significance was not attained, and a low dose (0.25 mg/kg) was ineffective. Neither drug afforded protection against the MPTP-induced loss of DA fibers in the striatum, as measured by TH-IR and dopamine transporter immunoreactive fiber counts. In conclusion, the novel naphotoxazine and dopaminergic agonist, S32504, robustly protects dopaminergic neurones against the neurotoxic effects of MPP(+) and MPTP in in vitro and in vivo models, respectively. The underlying mechanisms and therapeutic pertinence of these actions will be of interest to further evaluate in view of its potent actions in behavioral models of antiparkinson activity.
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Affiliation(s)
- Jeffrey N Joyce
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 852622, Sun City, AZ, USA.
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Muralikrishnan D, Samantaray S, Mohanakumar KP. D-deprenyl protects nigrostriatal neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurotoxicity. Synapse 2003; 50:7-13. [PMID: 12872288 DOI: 10.1002/syn.10239] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Selegiline (L-deprenyl) is believed to render protection against l-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-neurotoxicity to a significant extent via a free radical scavenging mechanism, which is independent of its ability to inhibit monoamine oxidase-B (MAO-B) in the brain. We investigated the hydroxyl radical (.OH) scavenging action and neuroprotective effect of D-deprenyl, its less active isomer, in MPTP-induced dopaminergic neurotoxicity in mice to test whether the chemical structure of the molecule or its biological effects contribute to this property. To achieve this goal we studied the effects of D-deprenyl on: (1).OH production in a Fenton reaction; (2) MPTP-induced.OH generation and dopamine (DA) depletion in vivo, employing a sensitive HPLC-electrochemical procedure; and (3) formation of MPP(+) in vivo in the striatum following systemic administration of MPTP, employing an HPLC-photodiode array detection system. D-deprenyl inhibited ferrous citrate-induced.OH in vitro (0.45 microM) and MPTP-induced.OH in vivo in substantia nigra (SN) and in the striatum (1.0 mg/kg, i.p.). D-deprenyl did not, but L-deprenyl (0.5 mg/kg dose) did significantly inhibit formation of MPP(+) in the striatum 90 min following systemic MPTP injection. It failed to affect MAO-B activity at 0.5 mg/kg in the striatum, but effectively blocked MPTP-induced striatal DA depletion. The potency of D-deprenyl to scavenge MPTP-induced.OH in vivo and to render protection against the dopaminergic neurotoxicity without affecting dopamine turnover, MAO-B activity, or formation of MPP(+) in the brain indicates a direct involvement of.OH in the neurotoxic action of MPTP and antioxidant effect in the neuroprotective action of deprenyl.
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Dragoni S, Bellik L, Frosini M, Matteucci G, Sgaragli G, Valoti M. Cytochrome P450-dependent metabolism of l-deprenyl in monkey (Cercopithecus aethiops) and C57BL/6 mouse brain microsomal preparations. J Neurochem 2003; 86:1174-80. [PMID: 12911625 DOI: 10.1046/j.1471-4159.2003.01927.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of the present investigation was to characterize the cytochrome P450 (CYP)-dependent metabolism of l-deprenyl by brain microsomal preparations obtained from two different animal models that have been extensively used in Parkinson's disease studies, namely monkey (Cercopithecus aethiops) and C57BL/6 mouse. In monkey brain microsomal fractions, the apparent Km values for methamphetamine formation from l-deprenyl were 67.8 +/- 1.0 and 72.0 +/- 1.6 microm, in the cortex and striatum, respectively. Similarly, for nordeprenyl formation from l-deprenyl, Km values in cortex and striatum were 21.3 +/- 3.2 and 27.3 +/- 4.0 microm, respectively. Both metabolic pathways appear to be more efficient in the cortex than in the striatum as the Vmax for microsomal preparation was lower in the striatum for the formation of both metabolites. The formation rate of l-methamphetamine was up to one order of magnitude greater than that of nordeprenyl. Inhibition analysis of both pathways in monkey brain suggested that l-methamphetamine formation is catalysed by CYP2A and CYP3A, whereas only CYP3A appears to be involved in nordeprenyl formation. With microsomal preparations from whole brain of C57BL/6 mice, the only l-deprenyl metabolite that could be detected was methamphetamine and the Km and Vmax values were similar to those determined in monkey cortex (53.6 +/- 2.9 microm and 33.9 +/- 0.4 pmol/min/mg protein, respectively). 4-Methylpyrazole selectively inhibited methamphetamine formation, suggesting the involvement of CYP2E1. In conclusion, the present study indicates that l-deprenyl is effectively metabolised by CYP-dependent oxidases in the brain, giving rise mainly to the formation of methamphetamine, which has been suggested to play a role in the pharmacological effects of the parent drug. The results also demonstrate that there are differences between species in CYP-dependent metabolism of l-deprenyl.
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Affiliation(s)
- Stefania Dragoni
- Istituto di Scienze Farmacologiche, Centro Interdipartimentale di Ricerca sul Metabolismo dei Farmaci Neuropsicotropi, Università di Siena, Siena, Italy
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Salonen JS, Nyman L, Boobis AR, Edwards RJ, Watts P, Lake BG, Price RJ, Renwick AB, Gómez-Lechón MJ, Castell JV, Ingelman-Sundberg M, Hidestrand M, Guillouzo A, Corcos L, Goldfarb PS, Lewis DFV, Taavitsainen P, Pelkonen O. Comparative studies on the cytochrome p450-associated metabolism and interaction potential of selegiline between human liver-derived in vitro systems. Drug Metab Dispos 2003; 31:1093-102. [PMID: 12920164 DOI: 10.1124/dmd.31.9.1093] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Selegiline was used as a model compound in a project aimed at comparing, evaluating, and integrating different in vitro approaches for the prediction of cytochrome p450 (p450)-catalyzed hepatic drug metabolism in humans (EUROCYP). Metabolic predictions were generated using homology modeling, cDNA-expressed p450 enzymes, human liver microsomes, primary cultured human hepatocytes, and precision-cut human liver slices. All of the in vitro systems correctly indicated the formation of two dealkylated metabolites, desmethylselegiline and methamphetamine. The metabolic instability of selegiline was demonstrated by all of the in vitro systems studied. Estimates of clearance varied from 16 l/h to 223 l/h. With the exception of one approach, all systems underpredicted the in vivo clearance in humans (236 l/h). Despite this, all approaches successfully classified selegiline as a high clearance compound. Homology modeling suggested the participation of CYP2B6 in the demethylation of selegiline and of CYP2D6 in the depropargylation of the drug. Studies with recombinant expressed enzymes and with human hepatic microsomal fraction supported the involvement of CYP2B6 but not of CYP2D6. These techniques also suggested the involvement of CYP1A2, CYP2C8, and CYP2C19 in the biotransformation of selegiline. In vitro, CYP2B6 was the most active form of p450 involved in selegiline metabolism. Metabolism by several enzymes operating in parallel implies a low interaction potential for the drug. None of the techniques alone was able to predict all aspects of the metabolic and kinetic behavior of selegiline in vivo. However, when used as an integrated package, all significant characteristics were predictable.
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Stocchi F, Olanow CW. Neuroprotection in Parkinson's disease: clinical trials. Ann Neurol 2003; 53 Suppl 3:S87-97; discussion S97-9. [PMID: 12666101 DOI: 10.1002/ana.10488] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Advances in our understanding of the cause and pathogenesis of Parkinson's disease (PD) have permitted the rational selection of putative neuroprotective agents for study in PD. However, the list of agents that might provide neuroprotective effects derived from laboratory studies is daunting, and we face the challenge of determining which agents to bring to the clinic and how to find the resources (patients and funds) to properly study so many promising therapeutic opportunities.1 Appropriate outcome variables that are not confounded by any symptomatic effect of the drug and are acceptable to clinicians and regulatory authorities also remain to be defined. The first clinical trials designed to test the capacity of putative neuroprotective agents to alter the natural history of PD have now been performed and illustrate some of these problems. The DATATOP (Deprenyl and Tocopherol Antioxidant Therapy of PD) study used the time to reach a disease milestone in untreated PD patients (ie, need for levodopa) as the primary end point. However, interpretation of results was confounded by the drug's symptomatic effect. The SINDEPAR (Sinemet-Deprenyl-Parlodel) study used the change in motor score between initial visit and final visit after washout of all study medications as the primary end point. However, here too there were concerns about confounding symptomatic effects, because antiparkinsonian medications have now been shown to have a long duration response that can persist for weeks and perhaps even months after withdrawal. More recent studies have used surrogate markers of the integrity of nigrostriatal function such as striatal uptake of fluorodopa on positron emission tomography (PET) or beta-CIT-on single-photon emission computerized tomography (SPECT) as primary outcome measures. However, it has not yet been confirmed that striatal uptake of these isotopes does in fact correlate with the remaining number of dopamine neurons or terminals, and the possibility of a confounding pharmacological effect has not yet been completely excluded. To date, no drug has been established to have a neuroprotective effect in PD, and none has been approved for a neuroprotective indication. Furthermore, regulatory agencies have not yet agreed that any of the outcome measures currently used will be acceptable for approval of a new drug. Resolution of these issues is of critical importance to convince pharmaceutical companies to expend the hundreds of millions of dollars necessary to bring a new drug to market. Drugs that already have been approved in PD for their symptomatic effects, such as dopamine agonists or propargylamines (eg, selegiline), offer the best opportunity for establishing that a drug is neuroprotective in PD in the immediate future, but herein also lies the difficulty of establishing that any benefits observed are not solely because of the drug's symptomatic properties. Currently, this will most likely entail demonstrating that the drug provides benefit for PD patients for both imaging and clinical markers of disease progression.
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Affiliation(s)
- Fabrizio Stocchi
- Department of Neuroscience and Neuromed, University La Sapienza, Rome, Italy.
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