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Wang W, Zhao J, Li Z, Kang X, Li T, Isaev NK, Smirnova EA, Shen H, Liu L, Yu Y. L-DOPA ameliorates hippocampus-based mitochondria respiratory dysfunction caused by GCI/R injury. Biomed Pharmacother 2024; 175:116664. [PMID: 38678966 DOI: 10.1016/j.biopha.2024.116664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/14/2024] [Accepted: 04/24/2024] [Indexed: 05/01/2024] Open
Abstract
Mitochondrial dysmorphology/dysfunction follow global cerebral ischemia-reperfusion (GCI/R) injury, leading to neuronal death. Our previous researches demonstrated that Levodopa (L-DOPA) improves learning and memory impairment in GCI/R rats by increasing synaptic plasticity of hippocampal neurons. This study investigates if L-DOPA, used in Parkinson's disease treatment, alleviates GCI/R-induced cell death by enhancing mitochondrial quality. Metabolomics and transcriptomic results showed that GCI/R damage affected the Tricarboxylic acid (TCA) cycle in the hippocampus. The results of this study show that L-DOPA stabilized mitochondrial membrane potential and ultrastructure in hippocampus of GCI/R rats, increased dopamine level in hippocampus, decreased succinic acid level, and stabilized Ca2+ level in CA1 subregion of hippocampus. As a precursor of dopamine, L-DOPA is presumed to improves mitochondrial function in hippocampus of GCI/R rats. However, dopamine cannot cross the blood-brain barrier, so L-DOPA is used in clinical therapy to supplement dopamine. In this investigation, OGD/R models were established in isolated mouse hippocampal neurons (HT22) and primary rat hippocampal neurons. Notably, dopamine exhibited a multifaceted impact, demonstrating inhibition of mitochondrial reactive oxygen species (mitoROS) production, stabilization of mitochondrial membrane potential and Ca2+ level, facilitation of TCA circulation, promotion of aerobic respiratory metabolism, and downregulation of succinic acid-related gene expression. Consistency between in vitro and in vivo results underscores dopamine's significant neuroprotective role in mitigating mitochondrial dysfunction following global cerebral hypoxia and ischemia injury. Supplement dopamine may represent a promising therapy to the cognitive impairment caused by GCI/R injury.
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Affiliation(s)
- Wenzhu Wang
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China; Wenzhou Medical University, Wenzhou, PR China; Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, PR China
| | - Jingyu Zhao
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, PR China
| | - Zihan Li
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China; Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, PR China
| | - Xiaoyu Kang
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China
| | - Ting Li
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China; Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, PR China
| | - Nickolay K Isaev
- Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia; Research Center of Neurology, Moscow, Russia
| | - Elena A Smirnova
- Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia; Department of Biology, MSU-BIT University, Shenzhen, PR China
| | - Hui Shen
- Dept of Cellular Biology, School of Basic Medical Science, Tianjin Medical University, Tianjin, PR China.
| | - Lixu Liu
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China; School of Rehabilitation Medicine, Capital Medical University, Beijing, PR China.
| | - Yan Yu
- China Rehabilitation Science Institute, China Rehabilitation Research Center, Beijing, PR China; Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, PR China; Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, PR China; School of Rehabilitation Medicine, Capital Medical University, Beijing, PR China.
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Jodko-Piórecka K, Sikora B, Kluzek M, Przybylski P, Litwinienko G. Antiradical Activity of Dopamine, L-DOPA, Adrenaline, and Noradrenaline in Water/Methanol and in Liposomal Systems. J Org Chem 2021; 87:1791-1804. [PMID: 34871499 PMCID: PMC8822484 DOI: 10.1021/acs.joc.1c02308] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Catecholamines play
a crucial role in signal transduction and are
also expected to act as endogeneous antioxidants, but the mechanism
of their antioxidant action is not fully understood. Here, we describe
the impact of pH on the kinetics of reaction of four catecholamines
(L-DOPA, dopamine, adrenaline, and noradrenaline) with model 2,2-diphenyl-1-picrylhydrazyl
radical (dpph•) in methanol/water. The increase
in pH from 5.5 to 7.4 is followed by a 2 order of magnitude increase
in the rate constant, e.g., for dopamine (DA) kpH5.5 = 1,200 M–1 s–1 versus kpH7.4 = 170,000 M–1 s–1, and such rate acceleration is attributed to a fast
electron transfer from the DA anion to dpph•. We
also proved that at pH 7.0 DA breaks the peroxidation chain of methyl
linoleate in liposomes assembled from neutral and negatively charged
phospholipids. In contrast to no inhibitory effect during peroxidation
in non-ionic emulsions, in bilayers one molecule of DA traps approximately
four peroxyl radicals, with a rate constant kinh >103 M–1 s–1. Our results from a homogeneous system and bilayers prove that catecholamines
act as effective, radical trapping antioxidants with activity depending
on the ionization status of the catechol moiety, as well as microenvironment:
organization of the lipid system (emulsions vs bilayers) and interactions
of catecholamines with the biomembrane.
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Affiliation(s)
| | - Bożena Sikora
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Monika Kluzek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Paweł Przybylski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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Mukai K, Nagai K, Egawa Y, Ouchi A, Nagaoka SI. Kinetic Study of Aroxyl-Radical-Scavenging and α-Tocopherol-Regeneration Rates of Five Catecholamines in Solution: Synergistic Effect of α-Tocopherol and Catecholamines. J Phys Chem B 2016; 120:7088-97. [PMID: 27346174 DOI: 10.1021/acs.jpcb.6b04285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Detailed kinetic studies have been performed for reactions of aroxyl (ArO(•)) and α-tocopheroxyl (α-Toc(•)) radicals with five catecholamines (CAs) (dopamine (DA), norepinephrine (NE), epinephrine (EN), and 5- and 6-hydroxydopamine (5- and 6-OHDA)) and two catechins (epicatechin (EC) and epigallocatechin gallate (EGCG)) to clarify the free-radical-scavenging activity of CAs. Second-order rate constants (ks and kr) for reactions of ArO(•) and α-Toc(•) radicals with the above antioxidants were measured in 2-propanol/water (5:1, v/v) solution at 25.0 °C, using single- and double-mixing stopped-flow spectrophotometries, respectively. Both the rate constants (ks and kr) increased in the order NE < EN < DA < EC < 5-OHDA < EGCG < 6-OHDA. The ks and kr values of 6-OHDA are large and comparable to the corresponding values of ubiquinol-10 and sodium ascorbate, which show high free-radical-scavenging activity. The ultraviolet-visible absorption of α-Toc(•) (λmax = 428 nm), which was produced by the reaction of α-tocopherol (α-TocH) with ArO(•), disappeared under the coexistence of CAs due to the α-TocH-regeneration reaction. The results suggest that the CAs may contribute to the protection from oxidative damage in nervous systems, by scavenging free radicals (such as lipid peroxyl radical) and regenerating α-TocH from the α-Toc(•) radical.
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Affiliation(s)
- Kazuo Mukai
- Department of Chemistry, Faculty of Science, Ehime University , Matsuyama 790-8577, Japan
| | - Kanae Nagai
- Department of Chemistry, Faculty of Science, Ehime University , Matsuyama 790-8577, Japan
| | - Yoshifumi Egawa
- Department of Chemistry, Faculty of Science, Ehime University , Matsuyama 790-8577, Japan
| | - Aya Ouchi
- Department of Chemistry, Faculty of Science, Ehime University , Matsuyama 790-8577, Japan
| | - Shin-Ichi Nagaoka
- Department of Chemistry, Faculty of Science, Ehime University , Matsuyama 790-8577, Japan
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Ganie SA, Dar TA, Bhat AH, Dar KB, Anees S, Zargar MA, Masood A. Melatonin: A Potential Anti-Oxidant Therapeutic Agent for Mitochondrial Dysfunctions and Related Disorders. Rejuvenation Res 2015; 19:21-40. [PMID: 26087000 DOI: 10.1089/rej.2015.1704] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mitochondria play a central role in cellular physiology. Besides their classic function of energy metabolism, mitochondria are involved in multiple cell functions, including energy distribution through the cell, energy/heat modulation, regulation of reactive oxygen species (ROS), calcium homeostasis, and control of apoptosis. Simultaneously, mitochondria are the main producer and target of ROS with the result that multiple mitochondrial diseases are related to ROS-induced mitochondrial injuries. Increased free radical generation, enhanced mitochondrial inducible nitric oxide synthase (iNOS) activity, enhanced nitric oxide (NO) production, decreased respiratory complex activity, impaired electron transport system, and opening of mitochondrial permeability transition pores have all been suggested as factors responsible for impaired mitochondrial function. Because of these, neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and aging, are caused by ROS-induced mitochondrial dysfunctions. Melatonin, the major hormone of the pineal gland, also acts as an anti-oxidant and as a regulator of mitochondrial bioenergetic function. Melatonin is selectively taken up by mitochondrial membranes, a function not shared by other anti-oxidants, and thus has emerged as a major potential therapeutic tool for treating neurodegenerative disorders. Multiple in vitro and in vivo experiments have shown the protective role of melatonin for preventing oxidative stress-induced mitochondrial dysfunction seen in experimental models of PD, AD, and HD. With these functions in mind, this article reviews the protective role of melatonin with mechanistic insights against mitochondrial diseases and suggests new avenues for safe and effective treatment modalities against these devastating neurodegenerative diseases. Future insights are also discussed.
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Affiliation(s)
- Showkat Ahmad Ganie
- 1 Department of Clinical Biochemistry, University of Kashmir Srinagar , India
| | - Tanveer Ali Dar
- 1 Department of Clinical Biochemistry, University of Kashmir Srinagar , India
| | - Aashiq Hussain Bhat
- 1 Department of Clinical Biochemistry, University of Kashmir Srinagar , India
| | - Khalid B Dar
- 1 Department of Clinical Biochemistry, University of Kashmir Srinagar , India
| | - Suhail Anees
- 1 Department of Clinical Biochemistry, University of Kashmir Srinagar , India
| | | | - Akbar Masood
- 2 Department of Biochemistry, University of Kashmir Srinagar , India
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Jodko-Piórecka K, Litwinienko G. Antioxidant activity of dopamine and L-DOPA in lipid micelles and their cooperation with an analogue of α-tocopherol. Free Radic Biol Med 2015; 83:1-11. [PMID: 25701434 DOI: 10.1016/j.freeradbiomed.2015.02.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/20/2015] [Accepted: 02/09/2015] [Indexed: 12/16/2022]
Abstract
Oxidative stress contributes to the progression of neurodegenerative diseases and considerable attention has been given to the development of new antioxidant-based therapies aimed at limiting neuronal cell damage. Structural analysis of catecholamine neurotransmitters indicates that these molecules can exhibit antioxidant activity due to the presence of a catechol moiety. This hypothesis is confirmed in cell culture experiments but the mechanism of antioxidant action of catecholamines is not described. Herein, we present quantitative kinetic studies on the effect of dopamine (DA) and L-3,4-dihydroxyphenylalanine (L-DOPA) on the peroxidation of methyl linoleate dispersed in Triton X-100 micelles as a model heterogeneous lipid system. Experiments were performed at extended pH range 4.0-10.0 in order to study how protonation/deprotonation of catecholamine affect its antioxidant activity. At pH 4.0-7.0, the activity of catecholamines is limited to retardation of lipid peroxidation (caused by the reaction of catecholamines with initiating radicals in the aqueous phase). The effective suppression of lipid peroxidation can be achieved by applying catecholamines together with an analogue of α-tocopherol (2,2,5,7,8-pentamethyl-6-hydroxychroman, PMHC). For example, a mixture of 1 μM PMHC with 10 μM L-DOPA causes 18-fold elongation of suppression time as compared to 1 μM PMHC used alone. We suggest that catecholamines together with α-tocopherol efficiently enhance the protection of biological systems from oxidative stress. At pH above 8.0 a prooxidative effect caused by reaction of semiquinone radical anions with molecular oxygen is observed. However, this toxic action can be completely suppressed by PMHC acting as an agent removing the potentially harmful semiquinone radicals from the reaction environment.
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Jodko-Piorecka K, Litwinienko G. First experimental evidence of dopamine interactions with negatively charged model biomembranes. ACS Chem Neurosci 2013; 4:1114-22. [PMID: 23662798 DOI: 10.1021/cn4000633] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Dopamine is essential for receptor-related signal transduction in mammalian central and peripheral nervous systems. Weak interactions between the neurotransmitter and neuronal membranes have been suggested to modulate synaptic transmission; however, binding forces between dopamine and neuronal membranes have not yet been quantitatively described. Herein, for the first time, we have explained the nature of dopamine interactions with model lipid membranes assembled from neutral 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG), and the mixture of these two lipids using isothermal titration calorimetry and differential scanning calorimetry. Dopamine binding to anionic membranes is a thermodynamically favored process with negative enthalpy and positive entropy, quantitatively described by the mole ratio partition coefficient, K. K increases with membrane charge to reach its maximal value, 705.4 ± 60.4 M(-1), for membrane composed from pure DMPG. The contribution of hydrophobic effects to the binding process is expressed by the intrinsic partition coefficient, K(0). The value of K(0) = 74.7 ± 6.4 M(-1) for dopamine/DMPG interactions clearly indicates that hydrophobic effects are 10 times weaker than electrostatic forces in this system. The presence of dopamine decreases the main transition temperature of DMPG, but no similar effect has been observed for DMPC. Basing on these results, we propose a simple electrostatic model of dopamine interactions with anionic membranes with the hydrophobic contribution expressed by K(0). We suggest that dopamine interacts superficially with phospholipid membranes without penetrating into the bilayer hydrocarbon core. The model is physiologically important, since neuronal membranes contain a large (even 20%) fraction of anionic lipids.
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Affiliation(s)
- Katarzyna Jodko-Piorecka
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
- MEMPHYS − Center for
Biomembrane Physics, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230
Odense M, Denmark
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7
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Escames G, López A, García JA, García L, Acuña-Castroviejo D, García JJ, López LC. The role of mitochondria in brain aging and the effects of melatonin. Curr Neuropharmacol 2011; 8:182-93. [PMID: 21358969 PMCID: PMC3001212 DOI: 10.2174/157015910792246245] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/24/2010] [Accepted: 05/05/2010] [Indexed: 12/14/2022] Open
Abstract
Melatonin is an endogenous indoleamine present in different tissues, cellular compartments and organelles including mitochondria. When melatonin is administered orally, it is readily available to the brain where it counteracts different processes that occur during aging and age-related neurodegenerative disorders. These aging processes include oxidative stress and oxidative damage, chronic and acute inflammation, mitochondrial dysfunction and loss of neural regeneration. This review summarizes age related changes in the brain and the importance of oxidative/nitrosative stress and mitochondrial dysfunction in brain aging. The data and mechanisms of action of melatonin in relation to aging of the brain are reviewed as well.
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Affiliation(s)
- Germaine Escames
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, Granada, Spain
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8
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Esposito E, Cuzzocrea S. Antiinflammatory activity of melatonin in central nervous system. Curr Neuropharmacol 2010; 8:228-42. [PMID: 21358973 PMCID: PMC3001216 DOI: 10.2174/157015910792246155] [Citation(s) in RCA: 268] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 04/25/2010] [Accepted: 05/08/2010] [Indexed: 12/15/2022] Open
Abstract
Melatonin is mainly produced in the mammalian pineal gland during the dark phase. Its secretion from the pineal gland has been classically associated with circadian and circanual rhythm regulation. However, melatonin production is not confined exclusively to the pineal gland, but other tissues including retina, Harderian glands, gut, ovary, testes, bone marrow and lens also produce it. Several studies have shown that melatonin reduces chronic and acute inflammation. The immunomodulatory properties of melatonin are well known; it acts on the immune system by regulating cytokine production of immunocompetent cells. Experimental and clinical data showing that melatonin reduces adhesion molecules and pro-inflammatory cytokines and modifies serum inflammatory parameters. As a consequence, melatonin improves the clinical course of illnesses which have an inflammatory etiology. Moreover, experimental evidence supports its actions as a direct and indirect antioxidant, scavenging free radicals, stimulating antioxidant enzymes, enhancing the activities of other antioxidants or protecting other antioxidant enzymes from oxidative damage. Several encouraging clinical studies suggest that melatonin is a neuroprotective molecule in neurodegenerative disorders where brain oxidative damage has been implicated as a common link. In this review, the authors examine the effect of melatonin on several neurological diseases with inflammatory components, including dementia, Alzheimer disease, Parkinson disease, multiple sclerosis, stroke, and brain ischemia/reperfusion but also in traumatic CNS injuries (traumatic brain and spinal cord injury).
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Affiliation(s)
- Emanuela Esposito
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy
| | - Salvatore Cuzzocrea
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy
- IRCCS Centro Neurolesi "Bonino-Pulejo", Messina, Italy
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Abstract
Melatonin plays a neuroprotective role in models of neurodegenerative diseases. However, the molecular mechanisms underlying neuroprotection by melatonin are not well understood. Apoptotic cell death in the central nervous system is a feature of neurodegenerative diseases. The intrinsic and extrinsic apoptotic pathways and the antiapoptotic survival signal pathways play critical roles in neurodegeneration. This review summarizes the reports to date showing inhibition by melatonin of the intrinsic apoptotic pathways in neurodegenerative diseases including stroke, Alzheimer disease, Parkinson disease, Huntington disease, and amyotrophic lateral sclerosis. Furthermore, the activation of survival signal pathways by melatonin in neurodegenerative diseases is discussed.
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Affiliation(s)
- Xin Wang
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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10
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Fitzpatrick KM, Raschke J, Emborg ME. Cell-based therapies for Parkinson's disease: past, present, and future. Antioxid Redox Signal 2009; 11:2189-208. [PMID: 19485712 PMCID: PMC2861536 DOI: 10.1089/ars.2009.2654] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Parkinson's disease (PD) researchers have pioneered the use of cell-based therapies (CBTs) in the central nervous system. CBTs for PD were originally envisioned as a way to replace the dopaminergic nigral neurons lost with the disease. Several sources of catecholaminergic cells, including autografts of adrenal medulla and allografts or xenografts of mesencephalic fetal tissue, were successfully assessed in animal models, but their clinical translation has yielded poor results and much controversy. Recent breakthroughs on cell biology are helping to develop novel cell lines that could be used for regenerative medicine. Their future successful clinical application depends on identifying and solving the problems encountered in previous CBTs trials. In this review, we critically analyze past CBTs' clinical translation, the impact of the host in graft survival, and the role of preclinical studies and emerging new cell lines. We propose that the prediction of clinical results from preclinical studies requires experimental designs that allow blind data acquisition and statistical analysis, assessment of the therapy in models that parallel clinical conditions, looking for sources of complications or side effects, and limiting optimism bias when reporting outcomes.
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Affiliation(s)
- Kathleen M Fitzpatrick
- Preclinical Parkinson's Research Program, Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin 53715, USA
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Mellios K, Zacharaki T, Sophou S, Latsari M, Antonopoulos J, Dinopoulos A, Parnavelas J, Dori I. Natural and lesion-induced apoptosis in the rat striatum during development. Brain Res 2009; 1252:30-44. [DOI: 10.1016/j.brainres.2008.10.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 09/17/2008] [Accepted: 10/06/2008] [Indexed: 12/01/2022]
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Abstract
The regulated production of neurons in the hippocampus throughout life underpins important brain functions such as learning and memory. Surprisingly, however, studies have so far failed to identify a resident hippocampal stem cell capable of providing the renewable source of these neurons. Here, we report that depolarizing levels of KCl produce a threefold increase in the number of neurospheres generated from the adult mouse hippocampus. Most interestingly, however, depolarizing levels of KCl led to the emergence of a small subpopulation of precursors (approximately eight per hippocampus) with the capacity to generate very large neurospheres (> 250 microm in diameter). Many of these contained cells that displayed the cardinal properties of stem cells: multipotentiality and self-renewal. In contrast, the same conditions led to the opposite effect in the other main neurogenic region of the brain, the subventricular zone, in which neurosphere numbers decreased by approximately 40% in response to depolarizing levels of KCl. Most importantly, we also show that the latent hippocampal progenitor population can be activated in vivo in response to prolonged neural activity found in status epilepticus. This work provides the first direct evidence of a latent precursor and stem cell population in the adult hippocampus, which is able to be activated by neural activity. Because the latent population is also demonstrated to reside in the aged animal, defining the precise mechanisms that underlie its activation may provide a means to combat the cognitive deficits associated with a decline in neurogenesis.
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Silvers JM, Aksenova MV, Aksenov MY, Mactutus CF, Booze RM. Neurotoxicity of HIV-1 Tat protein: involvement of D1 dopamine receptor. Neurotoxicology 2007; 28:1184-90. [PMID: 17764744 PMCID: PMC2957183 DOI: 10.1016/j.neuro.2007.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2006] [Revised: 07/16/2007] [Accepted: 07/16/2007] [Indexed: 01/15/2023]
Abstract
Neurotoxic viral proteins released from HIV-infected cells are believed to play a major role in the pathogenesis of the dementia displayed in a significant number of AIDS patients. HIV-1 associated neuropathology severely affects dopaminergic regions of the brain. Growing evidence indicates that HIV-1 neurotoxic proteins, such as Tat may affect the function of the dopamine transmission system. In turn, molecular components of dopamine neurotransmission may participate in a complex network of Tat-induced cell responses which result in neurodegeneration. In this study we investigated whether D1 dopamine receptors are involved in the mechanism of Tat neurotoxicity in primary rat neuronal cell cultures. We found that in rat midbrain cell cultures, which express significant levels of D1 dopamine receptors, the specific D1 antagonist SCH 23390 attenuates the cell death caused by HIV-1 Tat. In rat hippocampal cell cultures, where the expression of D1 receptors is low, SCH 23390 did not change the toxicity of Tat. Thus, the protective effect of SCH 23390 in rat primary neuronal cell cultures is a function of the level of D1 receptor protein expression. Our results provide further evidence for the involvement of the dopaminergic transmission system in the mechanism of HIV-1 Tat neurotoxicity.
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Affiliation(s)
- Janelle M Silvers
- Program in Behavioral Neuroscience, Department of Psychology, University of South Carolina, Columbia, SC 29208, USA
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Ma L, Zhou J. Dopamine Promotes the Survival of Embryonic Striatal Cells: Involvement of Superoxide and Endogenous NADPH Oxidase. Neurochem Res 2006; 31:463-71. [PMID: 16758354 DOI: 10.1007/s11064-006-9038-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2005] [Indexed: 10/24/2022]
Abstract
The dopaminergic system appears early in mammalian brain development, and a neurodevelopmental role for dopamine (DA) has been suggested. In the present study, we found that DA markedly promoted the survival of embryonic striatal cells in cultures. The failure of DA receptor antagonists to block this survival-promoting effect and the capability of S-apomorphine, which is devoid of DA receptor agonist activity but possesses antioxidative activity as R-apomorphine and DA, to completely mimic this effect suggested that DA receptor activation was not required in the survival-promoting effect elicited by DA, and its antioxidative activity might be involved. Moreover, it was found that mRNA of NADPH oxidase was expressed in the embryonic striatum. Furthermore, DPI or apocynin, NADPH oxidase inhibitors, promoted the survival of embryonic striatal cells. Addition of either DA or DPI into striatal cell cultures decreased the superoxide level. These results indicate that the mechanisms underlying the neuroprotective effects of DA were likely associated with its antioxidative activity. NADPH oxidase might contribute, at least in part, to ROS generation.
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Affiliation(s)
- Liping Ma
- Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, China
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15
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Aksenov MY, Aksenova MV, Nath A, Ray PD, Mactutus CF, Booze RM. Cocaine-mediated enhancement of Tat toxicity in rat hippocampal cell cultures: the role of oxidative stress and D1 dopamine receptor. Neurotoxicology 2005; 27:217-28. [PMID: 16386305 DOI: 10.1016/j.neuro.2005.10.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 10/12/2005] [Accepted: 10/12/2005] [Indexed: 12/18/2022]
Abstract
It is becoming widely accepted that psychoactive drugs can significantly alter the progression of neuropathological changes in the HIV-infected brain. The use of cocaine can aggravate the neurotoxic effects of HIV-1 proteins such as HIV-1 transactivating protein Tat and virus' envelope protein gp120. HIV-1 Tat is believed to play an important role in pathogenesis of HIV dementia (HAD). Tat is neurotoxic and a constantly growing body of evidence suggests that the toxic effects of Tat are oxidative stress-dependent. The current study reports that recombinant Tat 1-72 triggered mitochondrial depolarization, increased intracellular production of reactive oxygen species (ROS) and protein oxidation, and caused neuronal degeneration in primary hippocampal rat cell cultures. A 10 microM dose of the antioxidant Trolox, the water-soluble analog of Vitamin E, ameliorated increased intracellular ROS production and prevented cell viability decline in Tat-treated cell cultures. This fact demonstrates that Tat-induced changes in neuronal oxidative status play an important role in the mechanism of Tat neurotoxicity. While non-toxic by itself, a physiologically relevant dose of cocaine (1.5 microM) significantly enhanced Tat-induced oxidative stress and neurotoxicity in rat hippocampal cell cultures. The antioxidant Trolox significantly improved the survival of neurons exposed to the combination of 50 nM Tat and 1.5 microM cocaine but did not provide complete protection. The specific D1 dopamine receptor antagonist SCH 23390 (10 microM) did not affect Tat toxicity, but did suppress cocaine-mediated potentiation of Tat toxicity. Our results demonstrate that cocaine-mediated potentiation of Tat neurotoxicity may be related to its ability to augment Tat-induced oxidative stress.
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Affiliation(s)
- Michael Y Aksenov
- Department of Psychology, Program in Behavioral Neuroscience, University of South Carolina, Columbia, SC 29208, USA.
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Donaldson AE, Marshall CE, Yang M, Suon S, Iacovitti L. Purified mouse dopamine neurons thrive and function after transplantation into brain but require novel glial factors for survival in culture. Mol Cell Neurosci 2005; 30:108-17. [PMID: 16024255 PMCID: PMC1949425 DOI: 10.1016/j.mcn.2005.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 05/25/2005] [Accepted: 06/14/2005] [Indexed: 11/17/2022] Open
Abstract
Cell replacement therapy in Parkinson's disease depends on a reliable source of purified dopamine (DA) neurons (PDN) and the identification of factors relevant to their survival. Our goal was to genetically tag and purify by flow cytometry embryonic midbrain DA neurons from a transgenic mouse line carrying 11 kb of human tyrosine hydroxylase promoter driving expression of the enhanced green fluorescent protein (GFP) for studies in vivo and in vitro. A 99% purification of GFP(+) cells was achieved. When transplanted into 6-hydroxydopamine-treated rat striatum, PDN survived, became well-integrated and produced recovery from amphetamine-induced motor behaviors. However, when grown in culture, PDN died within days of plating. No known growth factors prevented PDN death as did incubation with novel factors in glia/glial-conditioned media. We conclude that GFP-tagged DA neurons can be purified to homogeneity and can survive and function when grown with glial factors in vitro or after transplantation in vivo.
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Affiliation(s)
- A E Donaldson
- Farber Institute for Neurosciences, Thomas Jefferson University Medical College, Philadelphia, PA 19107, USA
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17
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Cosentino M, Rasini E, Colombo C, Marino F, Blandini F, Ferrari M, Samuele A, Lecchini S, Nappi G, Frigo G. Dopaminergic modulation of oxidative stress and apoptosis in human peripheral blood lymphocytes: evidence for a D1-like receptor-dependent protective effect. Free Radic Biol Med 2004; 36:1233-40. [PMID: 15110388 DOI: 10.1016/j.freeradbiomed.2004.02.065] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2003] [Revised: 02/02/2004] [Accepted: 02/19/2004] [Indexed: 10/26/2022]
Abstract
Dopamine (DA) is a neurotransmitter in the central and peripheral nervous system, which can be either cytotoxic or cytoprotective under selected conditions. Such effects involve oxidative mechanisms and are likely to play a role in neurodegenerative disorders. Because increasing evidence points to peripheral blood lymphocytes (PBL) as a feasible model for studying DA-related mechanisms of cell death and survival, we have explored in these cells the effects of DA on oxidative metabolism and apoptosis. Our results show that, whereas DA 100-500 microM resulted in increased intracellular reactive oxygen species (ROS) levels and apoptotic cell death through oxidative stress, DA 0.1-5 microM decreased ROS levels and apoptosis. DA (both 1 and 500 microM) partially counteracted the decrease in Cu/Zn superoxide dismutase levels observed in untreated PBL. However, whereas the effect of the low dose lasted for the whole incubation period (24 h), the effect of DA 500 microM was transient. DA-dependent reduction of ROS levels and apoptosis was prevented by D1-like (but not D2-like) receptor antagonism. The present findings add knowledge about the sensitivity of PBL to DA and strengthen the rationale for exploiting these cells as an easily accessible peripheral model for the ex vivo investigation of oxidative stress-related dopaminergic mechanisms underlying human neurodegenerative diseases.
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Affiliation(s)
- Marco Cosentino
- Center for Research in Clinical and Applied Pharmacology, University of Insubria and University of Pavia, 21100 Varese, VA, Italy.
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18
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Götz ME, Riederer P. Advances in Neuroprotection Research for Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 541:1-19. [PMID: 14977205 DOI: 10.1007/978-1-4419-8969-7_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Mario E Götz
- Institute of Pharmacology and Toxicology, 97078 Würzburg, Germany
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19
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Yang M, Donaldson AE, Marshall CE, Shen J, Iacovitti L. Studies on the differentiation of dopaminergic traits in human neural progenitor cells in vitro and in vivo. Cell Transplant 2004; 13:535-47. [PMID: 15565866 PMCID: PMC1949040 DOI: 10.3727/000000004783983729] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The development of cell replacement therapies for the treatment of neurodegenerative disorders such as Parkinson's disease (PD) may depend upon the successful differentiation of human neural stem/progenitor cells into dopamine (DA) neurons. We show here that primary human neural progenitors (HNPs) can be expanded and maintained in culture both as neurospheres (NSPs) and attached monolayers where they develop into neurons and glia. When transplanted into the 6-hydroxydopamine-lesioned rat striatum, undifferentiated NSPs survive longer (60% graft survival at 8-16 weeks vs. 30% graft survival at 8-13 weeks) and migrate farther than their attached counterparts. While both NSP and attached cells continue to express neuronal traits after transplantation, the spontaneous expression of differentiated transmitter-related traits is not observed in either cell type. However, following predifferentiation in culture using a previously described cocktail of reagents, approximately 25% of HNPs can permanently express the DA enzyme tyrosine hydroxylase (TH), even following replating and removal of the DA differentiation cocktail. When these predifferentiated HNPs are transplanted into the brain, however, TH staining is not observed, either because expression is lost or TH-expressing cells preferentially die. Consistent with the latter view is a decrease in total cell survival and migration, and an enhanced glial response in these grafts. In contrast, we found that the overall survival of HNPs is improved when cells engraft near blood vessels or CSF compartments or when they are placed into an intact unlesioned brain, suggesting that there are factors, as yet unidentified, that can better support the development of engrafted HNPs.
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Affiliation(s)
- Ming Yang
- Farber Institute for Neurosciences, Department of Neurology, Thomas Jefferson University Medical College, 900 Walnut Street, Philadelphia, PA 19107
| | - Angela E. Donaldson
- Farber Institute for Neurosciences, Department of Neurology, Thomas Jefferson University Medical College, 900 Walnut Street, Philadelphia, PA 19107
| | - Cheryl E. Marshall
- Farber Institute for Neurosciences, Department of Neurology, Thomas Jefferson University Medical College, 900 Walnut Street, Philadelphia, PA 19107
| | - James Shen
- ScienCell Research Laboratories, 4050 Sorrento Valley Boulevard, San Diego, CA 92121
| | - Lorraine Iacovitti
- Farber Institute for Neurosciences, Department of Neurology, Thomas Jefferson University Medical College, 900 Walnut Street, Philadelphia, PA 19107
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20
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Stroppolo A, Tian C, Guinea B, Olm V, Sheffield R, Sommer J, Ehrlich ME. 17beta-Estradiol promotes striatal medium size spiny neuronal maturation in vitro. Neuroendocrinology 2004; 79:259-67. [PMID: 15218319 DOI: 10.1159/000079320] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2003] [Accepted: 04/05/2004] [Indexed: 11/19/2022]
Abstract
Gender differences exist in the development of the nigrostriatal dopamine system, and in the incidence and course of pediatric and adult neuropsychiatric diseases in which this system is implicated. The medium size spiny neuron (MSN) is the major output neuron of the caudate nucleus. It receives a large dopaminergic input from the substantia nigra, and 96% of the MSNs express DARPP-32, a dopamine and cyclic AMP-regulated phosphoprotein and key mediator of dopamine function. There are few examples, however, of direct effects of sex hormones, including 17beta-estradiol (E(2)), on the MSN. We report that in vitro, E(2) (10-50 nM) promotes MSN phenotypic maturation, as determined by increased soma size, neurite length, and DARPP-32 protein levels. Treatment with the 'anti-estrogen' ICI 182,780 or the partial-agonist tamoxifen also increases DARPP-32 levels, but when added to E(2), ICI 182,780 only prevents the increase in DARPP-32 levels and increase in soma size and neurite length. Surprisingly, maturation effects are more robust in cells derived exclusively from female embryos. Western blot analysis of protein lysates and immunocytochemistry of cultured MSNs reveals the presence of the estrogen receptor beta (ERbeta). These data suggest that ERbeta may mediate the differentiating effect of E(2) on embryonic MSNs, and provide new avenues of investigation for the role of sex hormones in the development of the striatum and in diseases affecting the basal ganglia.
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21
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Stull ND, Polan DP, Iacovitti L. Antioxidant compounds protect dopamine neurons from death due to oxidative stress in vitro. Brain Res 2002; 931:181-5. [PMID: 11897104 DOI: 10.1016/s0006-8993(02)02269-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Using tissue culture models of oxidative stress caused by serum deprivation or MPTP/MPP+ toxicity, the present study establishes that the antioxidants epigallocatechin gallate, lazaroids U74389G and U83836E, reservatrol, MnTBAP, MCI 186, trolox, and melatonin protect 68-100% of dopamine (DA) neurons from cell death. In contrast, the nitric oxide inhibitor LY83583, the caspase inhibitors Z-VAD-FMK, Ac-DQMD-CHO and Z-DEVD-FMK, and the CDK-5 inhibitor, roscovotine were not neuroprotective, although death was often delayed by 1 day in vitro. We conclude that antioxidants are more effective at preventing cell death in vitro than are inhibitors at later stages in the death cascade.
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Affiliation(s)
- Natalie D Stull
- Department of Neurology, Thomas Jefferson University Medical College, Philadelphia, PA 19107, USA
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22
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Affiliation(s)
- C C Tangney
- Department of Clinical Nutrition, Rush Presbyterian St. Luke's Medical Center, 1700 West Van Buren Street, Chicago, IL 60612, USA.
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23
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Troadec JD, Marien M, Darios F, Hartmann A, Ruberg M, Colpaert F, Michel PP. Noradrenaline provides long-term protection to dopaminergic neurons by reducing oxidative stress. J Neurochem 2001; 79:200-10. [PMID: 11595772 DOI: 10.1046/j.1471-4159.2001.00556.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To better understand the neurotrophic function of the neurotransmitter noradrenaline, we have developed a model of mesencephalic cultures in which we find low concentrations (0.3-10 microM) of noradrenaline to be remarkably effective in promoting long-term survival and function of dopaminergic neurons. This protective action reproduced the effect of caspase inhibition. It was atypical in that it occurred independently of adrenoceptor activation and was mimicked by some antioxidants, redox metal chelators and the hydroxyl radical detoxifying enzyme catalase. Interestingly, intracellular reactive oxygen species (ROS) were drastically reduced by treatment with noradrenaline, indicating that the neurotransmitter itself acted as an antioxidant. Prevention of oxidative stress was, however, independent of the glutathione antioxidant defense system. Chemical analogues of noradrenaline bearing two free hydroxyl groups in the ortho position of the aromatic ring (o-catechols), as well as o-catechol itself, mimicked the survival promoting effects of the neurotransmitter, suggesting that this diphenolic structure was critical for both neuroprotection and reduction of ROS production. Paradoxically, the autoxidation of noradrenaline and the ensuing production of quinone metabolites may be required for both effects, as the neurotransmitter was spontaneously and rapidly degraded over time in the culture medium. These results support the concept that central noradrenergic mechanisms have a neuroprotective role, perhaps in part by reducing oxidative stress.
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MESH Headings
- Animals
- Antioxidants/pharmacology
- Catalase/pharmacology
- Catechols/chemistry
- Cell Death/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- Chelating Agents/pharmacology
- Dopamine/physiology
- Embryo, Mammalian
- Glutathione/metabolism
- Iron/metabolism
- Mesencephalon
- Neurons/drug effects
- Neurons/physiology
- Norepinephrine/analogs & derivatives
- Norepinephrine/chemistry
- Norepinephrine/pharmacology
- Oxidation-Reduction
- Oxidative Stress/drug effects
- Rats
- Rats, Wistar
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/physiology
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/physiology
- Structure-Activity Relationship
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Affiliation(s)
- J D Troadec
- INSERM U289, Experimental Neurology and Therapeutics, Hôpital de la Salpêtrière, Paris, France
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24
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Stull ND, Jung JW, Iacovitti L. Induction of a dopaminergic phenotype in cultured striatal neurons by bone morphogenetic proteins. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2001; 130:91-8. [PMID: 11557097 DOI: 10.1016/s0165-3806(01)00216-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the present study, we examined whether the bone morphogenetic proteins (BMPs), which are important in the developmental specification of transmitter type in certain classes of neurons, might also play a role in signaling the differentiation of a dopaminergic (DA) phenotype. We found that BMP-2, -4 and -6 were each capable of inducing, in a dose and time dependent manner, moderate levels of the DA enzyme tyrosine hydroxylase (TH) in cultured neurons from the mouse embryonic striatum. In contradistinction to other TH-inducing agents, BMPs initiated de novo TH expression without the required synergy of exogenous growth factors or co-activating substances and in neurons presumably aged (E16) beyond the critical period for induction. However, the appearance of TH in induced cells was short-lived (24 h) and could not be prolonged by repeated supplementation with the BMPs. Inhibitors of the mitogen-activated protein kinase (MAPK/ERK) signaling pathway, PD98059 and apigenin, did not prevent TH induction by BMP-4, as they did other TH inducing agents, indicating that the MAPK/ERK pathway does not mediate BMPs effects on TH expression. We conclude that BMP-2, -4 and -6 can be added to the expanding inventory of agents capable of inducing TH, making them potentially important in the specification of a DA phenotype in stem/precursor cells for the treatment of Parkinson's disease.
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Affiliation(s)
- N D Stull
- Department of Neurology, Thomas Jefferson University Medical College, 1025 Walnut Street, Philadelphia, PA 19107, USA
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25
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Douhou A, Troadec JD, Ruberg M, Raisman-Vozari R, Michel PP. Survival promotion of mesencephalic dopaminergic neurons by depolarizing concentrations of K+ requires concurrent inactivation of NMDA or AMPA/kainate receptors. J Neurochem 2001; 78:163-74. [PMID: 11432983 DOI: 10.1046/j.1471-4159.2001.00401.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The death of dopaminergic neurons that occurs spontaneously in mesencephalic cultures was prevented by depolarizing concentrations of K+ (20-50 mM). However, unlike that observed previously in other neuronal populations of the PNS or CNS, promotion of survival required concurrent blockade of either NMDA or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/kainate receptors by the specific antagonists, MK-801 and GYKI-52466, respectively. Rescued neurons appeared to be healthy and functional because the same treatment also dramatically enhanced their capacity to accumulate dopamine. The effects on survival and uptake were rather specific to dopaminergic neurons, rapidly reversible and still observed when treatment was delayed after plating. Glutamate release increased substantially in the presence of elevated concentrations of K+, and chronic treatment with glutamate induced a loss of dopaminergic neurons that was prevented by MK-801 or GYKI-52466 suggesting that an excitotoxic process interfered with survival when only the depolarizing treatment was applied. The effects of the depolarizing stimulus in the presence of MK-801 were mimicked by BAY K-8644 and abolished by nifedipine, suggesting that neuroprotection resulted from Ca(2+) influx through L-type calcium channels. Measurement of intracellular calcium revealed that MK-801 or GYKI-52466 were required to maintain Ca(2+) levels within a trophic range, thus preventing K+-induced excitotoxic stress and Ca(2+) overload. Altogether, our results suggest that dopaminergic neurons may require a finely tuned interplay between glutamatergic receptors and calcium channels for their development and maturation.
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Affiliation(s)
- A Douhou
- INSERM U289, Experimental Neurology and Therapeutics, Hôpital de la Salpêtríere, 47 Boulevard de l'Hôpital, 75013 Paris, France
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26
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Barzilai A, Melamed E, Shirvan A. Is there a rationale for neuroprotection against dopamine toxicity in Parkinson's disease? Cell Mol Neurobiol 2001; 21:215-35. [PMID: 11569535 DOI: 10.1023/a:1010991020245] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Parkinson's disease is a progressive neurological disease caused by rather selective degeneration of the dopaminergic neurons in the substantia nigra. Though subject to intensive research, the etiology of this nigral loss is still undetermined and treatment is basically symptomatic. The current major hypothesis is that nigral neuronal death in PD is due to excessive oxidative stress generated by auto and enzymatic oxidation of the endogenous neurotransmitter dopamine (DA), the formation of neuromelanin (NM) and the presence of a high concentration of iron. In this review article although we concisely describe the effects of NM and iron on neuronal survival, we mainly focus on the molecular mechanisms of DA-induced apoptosis. DA exerts its toxic effects through its oxidative metabolites either in vitro or in vivo The oxidative metabolites then activate a very intricate web of signals, which culminate in cell death. The signal transduction pathways and genes, which are associated with DA toxicity are described in detail.
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Affiliation(s)
- A Barzilai
- Department of Neurobiochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel.
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27
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Stull ND, Iacovitti L. Sonic hedgehog and FGF8: inadequate signals for the differentiation of a dopamine phenotype in mouse and human neurons in culture. Exp Neurol 2001; 169:36-43. [PMID: 11312556 DOI: 10.1006/exnr.2001.7640] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Embryonic mouse striatal neurons and human neurons derived from the NT2/hNT stem cell line can be induced, in culture, to express the dopaminergic (DA) biosynthetic enzyme tyrosine hydroxylase (TH). The novel expression of TH in these cells is signaled by the synergistic interaction of factors present in the media, such as fibroblast growth factor 1 (FGF1) and one of several possible coactivators [DA, phorbol 12-myristate 13-acetate (TPA), isobutylmethylxanthine (IBMX), or forskolin]. Similarly, in vivo, it has recently been reported that the expression of TH in the developing midbrain is mediated by the synergy of FGF8 and the patterning molecule sonic hedgehog (Shh). In the present study, we examined whether the putative in vivo DA differentiation factors can similarly signal TH in our in vitro cell systems. We found that FGF8 and Shh induced TH expression in fewer than 2% of NT2/hNT cells and less than 5% of striatal neurons. The latter could be amplified to as much as 30% by increasing the concentration of growth factor 10-fold or by the addition of other competent coactivators (IBMX/forskolin, TPA, and DA). Additivity/inhibitor experiments indicated that FGF8 worked through traditional tyrosine kinase-initiated MAP/MEK signaling pathways. However, the Shh signal transduction cascade remained unclear. These data suggest that cues effective in vivo may be less successful in promoting the differentiation of a DA phenotype in mouse and human neurons in culture. Thus, our ability to generate DA neurons from different cell lines, for use in the treatment of Parkinson's disease, will depend on the identification of appropriate differentiation signals for each cell type under investigation.
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Affiliation(s)
- N D Stull
- Department of Neurology, Thomas Jefferson University Medical College, 1025 Walnut Street, Philadelphia, Pennsylvania, 19107, USA
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28
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Abstract
A range of compounds in or derived from the diet modulates apoptosis in cell cultures in vitro. These observations have important implications concerning the mechanisms whereby dietary components affect health. Proapoptotic compounds could protect against cancer by enhancing elimination of initiated, precancerous cells, and antiapoptotic compounds could promote tumor formation by inhibiting apoptosis in genetically damaged cells. Proapoptotic compounds could also contribute to age-related degenerative diseases by activating cell death in postmitotic cells or shifting the normal balance of mitosis and apoptosis in tissues with regenerative capacity. Many age-related diseases, for example macular degeneration and Parkinson's disease, appear to have oxidative stress as an underlying component that interacts with genetic, dietary, and environmental factors to determine relative risk in an individual. Oxidative stress activates apoptosis, and antioxidants protect against apoptosis in vitro; thus, a central role of dietary antioxidants may be to protect against apoptosis. However, little in vivo data are available to directly link diet with altered apoptosis as an underlying determinant of disease. Moreover, the possible antagonistic effects of different dietary components and the uncertainty about whether proapoptotic compounds that may protect against cancer could contribute to degenerative diseases and vice versa indicate that there is a great need for better in vivo assessment of apoptosis and that caution should be exercised when extrapolating in vitro data on apoptosis to in vivo dietary recommendations.
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Affiliation(s)
- W H Watson
- Departments of Biochemistry and Ophthalmology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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29
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Abstract
The effects of dopamine and L-DOPA on survival were examined in differentiated PC12 cells. Addition of dopamine to the culture medium at 3-30 microM prevented cell death induced by depletion of serum and nerve growth factor (NGF). At 100 microM, dopamine induced cell death. The cell-protective effect of dopamine was not affected by nomifensine, an inhibitor of dopamine uptake, or pargyline, an inhibitor of monoamine oxidase, suggesting that dopamine is working outside the cell. The cell-protective effect of dopamine was blunted by SCH-23390, a D(1) antagonist, but not sulpiride, a D(2) antagonist, indicating that the cell protective effect of dopamine is mediated by D(1) receptors in PC12 cells. L-DOPA also protected PC12 cells from cell death induced by depletion of serum and NGF at low concentrations and showed toxicity at high concentration. The effect of L-DOPA was unchanged after inhibition of conversion of L-DOPA to dopamine by m-hydroxybenzylhydrazine (NSD-1015), an inhibitor of DOPA decarboxylase, suggesting that L-DOPA itself is working for cell protection. Intracellular Ca(2+) concentration and mitogen-activated protein (MAP) kinase activity were increased by both dopamine and L-DOPA. The effects of dopamine and L-DOPA on cell survival were blunted by nicardipine, a Ca(2+) channel blocker, and PD-98059, an inhibitor of MAP kinase kinase (MEK). These results taken together raised the possibility that dopamine and L-DOPA protect PC12 cells from cell death at low concentrations by activating MAP kinase activity via elevation of intracellular Ca(2+) concentration.
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Affiliation(s)
- K Koshimura
- First Division, Department of Medicine, Shimane Medical University, Izumo, Japan.
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30
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Abstract
This review covers certain novel aspects of catecholamine signaling in neurons that involve redox systems and synaptic plasticity. The redox hypothesis suggests that one important factor in neurocomputation is the formation of new synapses and the removal of old ones (synaptic plasticity), which is modulated in part by the redox balance at the synapse between reactive oxygen species (ROS) (such as hydrogen peroxide and the nitric oxide radical) and neuroprotective antioxidants (such as ascorbate, glutathione, and catecholamines). Catecholamines, in particular dopamine, which signals positive reinforcement, may play a key role in this activity. Dopamine has powerful antioxidant properties by several separate mechanisms-direct ROS scavenging, activation of the synthesis of antioxidant proteins, and possibly via dismuting complexes with iron inside endosomes or in catecholaminergic synaptic vesicles. This may contribute to synaptic growth and reinforcement-directed learning. On the other hand, catecholamines are easily oxidized to toxic quinones on the neuromelanin pathway. This might contribute under certain circumstances to synaptic deletion. Evidence is presented that abnormalities in this system may contribute to the pathogenesis of Parkinson's disease and schizophrenia.
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Affiliation(s)
- J Smythies
- Center for Brain and Cognition, Department of Psychology, University of California-San Diego, La Jolla 92093-0109, USA.
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31
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Abstract
Corticotropin releasing factor (CRF) is a 41 amino acid peptide that has been localized throughout the mouse cerebellum on postnatal day (P0). The wide-spread distribution of CRF within this brain region at birth suggests that it likely is present during embryonic stages of development. Thus, the intent of this study was to use immunohistochemical techniques to determine when CRF is first present in the cerebellar anlage, to analyze its distribution within the developing cerebellum, and to correlate these findings with early events in cerebellar ontogeny. CRF can first be detected in the cerebellum on embryonic day (E) 10 in scattered puncta that appear to approximate cell bodies throughout the cerebellar plate. Between E11 and E14 the number of puncta increase in the intermediate zone and more dorsal aspect of the cerebellum and decrease in the ventricular zone. At E14, in addition to the puncta, lightly immunolabeled cell bodies are observed in the ventricular zone. Just prior to birth at E17, CRF-immunoreactive varicosities distribute along the multitiered Purkinje cell layer and the intermediate zone. The CRF-positive cell bodies increase in number and intensity of staining. The majority remain within the ventricular zone, although a few also are present in the intermediate zone; it is postulated that these may be glial cells or neurons that are transiently expressing CRF. In conclusion, CRF-positive punctate elements derived from an as yet unknown source are present in the embryonic cerebellum just prior to and during the birth of Purkinje cells and nuclear neurons. The presence of this peptide at this critical stage of cerebellar development and its continued expression throughout the postnatal period of ontogeny suggests that CRF may play an important developmental role.
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Affiliation(s)
- G A Bishop
- Department of Neuroscience, The Ohio State University, Columbus 43210, USA
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32
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Expression of the striatal DARPP-32/ARPP-21 phenotype in GABAergic neurons requires neurotrophins in vivo and in vitro. J Neurosci 1999. [PMID: 10377350 DOI: 10.1523/jneurosci.19-13-05409.1999] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The medium spiny neuron (MSN) is the major output neuron of the caudate nucleus and uses GABA as its primary neurotransmitter. A majority of MSNs coexpress DARPP-32 and ARPP-21, two dopamine and cyclic AMP-regulated phosphoproteins, and most of the matrix neurons express calbindin. DARPP-32 is the most commonly used MSN marker, but previous attempts to express this gene in vitro have failed. In this study we found that DARPP-32 is expressed in <12% of E13- or E17-derived striatal neurons when they are grown in defined media at high or low density in serum, dopamine, or Neurobasal/N2 (Life Technologies), and ARPP-21 is expressed in <1%. The percentage increases to 25% for DARPP-32 and 10% for ARPP-21 when the same cells are grown in Neurobasal/B27 (Life Technologies) for 7 d. After growth in Neurobasal/B27 plus brain-derived neurotrophic factor (BDNF) for 7 d, E13-derived MSNs are 53.7% DARPP-32-positive and 29. 0% ARPP-21-positive; E17-derived MSNs are 66.8% DARPP-32-positive and 51.5% ARPP-21-positive. The percentage of calbindin-positive neurons also is increased under these conditions. Finally, ARPP-21 expression is reduced in mice with a targeted deletion of the BDNF gene. We conclude that BDNF is required for the maturation of a large subset of patch and matrix MSNs in vivo and in vitro. In addition, we introduce a culture system in which highly differentiated MSNs may be generated, maintained, and studied.
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