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Lyman E, Higgs C, Kim B, Lupyan D, Shelley JC, Farid R, Voth GA. A role for a specific cholesterol interaction in stabilizing the Apo configuration of the human A(2A) adenosine receptor. Structure 2010; 17:1660-1668. [PMID: 20004169 DOI: 10.1016/j.str.2009.10.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 10/06/2009] [Accepted: 10/15/2009] [Indexed: 10/20/2022]
Abstract
The function of G-protein-coupled receptors is tightly modulated by the lipid environment. Long-timescale molecular dynamics simulations (totaling approximately 3 mus) of the A(2A) receptor in cholesterol-free bilayers, with and without the antagonist ZM241385 bound, demonstrate the instability of helix II in the apo receptor in cholesterol-poor membrane regions. We directly observe that the effect of cholesterol binding is to stabilize helix II against a buckling-type deformation, perhaps rationalizing the observation that the A(2A) receptor couples to G protein only in the presence of cholesterol (Zezula and Freissmuth, 2008). The results suggest a mechanism by which the A(2A) receptor may function as a coincidence detector, activating only in the presence of both cholesterol and agonist. We also observed a previously hypothesized conformation of the tryptophan "rotameric switch" on helix VI in which a phenylalanine on helix V positions the tryptophan out of the ligand binding pocket.
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Affiliation(s)
- Edward Lyman
- Center for Biophysical Modeling and Simulation and Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Chris Higgs
- Schrödinger, L.L.C., 8910 University Center Lane, Suite 270, San Diego, CA 92122, USA
| | - Byungchan Kim
- Schrödinger, L.L.C., 120 West 45(th) Street, New York, NY 10036, USA
| | - Dmitry Lupyan
- Schrödinger, L.L.C., 120 West 45(th) Street, New York, NY 10036, USA; Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - John C Shelley
- Schrodinger, L.L.C., 101 S.W. Main Street, Suite 1300 Portland, OR 97204, USA
| | - Ramy Farid
- Schrödinger, L.L.C., 120 West 45(th) Street, New York, NY 10036, USA
| | - Gregory A Voth
- Center for Biophysical Modeling and Simulation and Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
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Alachkar A, Brotchie JM, Jones OT. Binding of dopamine and 3-methoxytyramine as l-DOPA metabolites to human alpha(2)-adrenergic and dopaminergic receptors. Neurosci Res 2010; 67:245-9. [PMID: 20302892 DOI: 10.1016/j.neures.2010.03.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/11/2010] [Accepted: 03/12/2010] [Indexed: 11/28/2022]
Abstract
The ability of l-3,4-dihydroxyphenylalanine (l-DOPA), l-DOPA-methyl ester and their major metabolites, dopamine, dihydroxyphenylacetic acid (DOPAC), homovanillic (HVA), 3-O-methyldopa and 3-methoxytyramine (3-MT) to bind to alpha(2) adrenergic and D1 and D2 dopamine receptors was assessed by radioligand binding to cloned human receptors expressed in cell lines. As anticipated, dopamine bound with high affinity to D1 (IC(50) 1.1 + or - 0.16 microM) and D2 (IC(50) 0.7 + or - 0.3 microM) dopamine receptors. However, dopamine also bound with high affinity to alpha(2A) (IC(50) was 2.6 + or - 0.5 microM), alpha(2C) (IC(50) 3.2 + or - 0.7 microM). 3-MT bound to alpha(2A) with high affinity (IC(50), 3.6 + or - 0.2 microM) though moderate affinity to alpha(2)c, D1 and D2 receptors (values of IC(50) were 55 + or - 14, 121 + or - 43, 36 + or - 14 microM, respectively). l-DOPA-methyl ester bound with high affinity to alpha(2) (IC(50) 17-36 microM) but not dopamine receptors (IC(50) 0.9-2.5 mM). l-DOPA, 3-O-methyldopa and DOPAC had no observable effect on binding to any of the receptors tested. These data suggest that the effects of l-DOPA in Parkinson's disease may result from actions of its metabolites dopamine and 3-MT on both dopaminergic and non-dopaminergic receptors. These findings may provide explanations for the differences between l-DOPA and dopamine receptor agonists in mediating anti-parkinsonian effects and propensity to be associated with dyskinesia and motor complications such as wearing-off and on-off.
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Affiliation(s)
- Amal Alachkar
- Division of Neuroscience, School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK.
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153
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Delattre AM, Kiss Á, Szawka RE, Anselmo-Franci JA, Bagatini PB, Xavier LL, Rigon P, Achaval M, Iagher F, de David C, Marroni NA, Ferraz AC. Evaluation of chronic omega-3 fatty acids supplementation on behavioral and neurochemical alterations in 6-hydroxydopamine-lesion model of Parkinson's disease. Neurosci Res 2010; 66:256-64. [DOI: 10.1016/j.neures.2009.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 10/16/2009] [Accepted: 11/18/2009] [Indexed: 01/29/2023]
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154
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Drastic decrease in dopamine receptor levels in the striatum of acetylcholinesterase knock-out mouse. Chem Biol Interact 2010; 183:194-201. [PMID: 19818744 DOI: 10.1016/j.cbi.2009.09.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/29/2009] [Accepted: 09/30/2009] [Indexed: 11/22/2022]
Abstract
BACKGROUND The acetylcholinesterase knock-out mouse lives to adulthood despite 60-fold elevated acetylcholine concentrations in the brain that are lethal to wild-type animals. Part of its mechanism of survival is a 50% decrease in muscarinic and nicotinic receptors and a 50% decrease in adrenoceptor levels. HYPOTHESIS The hypothesis was tested that the dopaminergic neuronal system had also adapted. METHODS Radioligand binding assays measured dopamine receptor level and binding affinity in the striatum. Immunohistochemistry of brain sections with specific antibodies visualized dopamine transporter. Effects on the intracellular compartment were measured as cAMP content, PI-phospholipase C activity. RESULTS Dopamine receptor levels were decreased 28-fold for the D(1)-like, and more than 37-fold for the D(2)-like receptors, though binding affinity was normal. Despite these huge changes in receptor levels, dopamine transporter levels were not affected. The intracellular compartment had normal levels of cAMP and PI-phospholipase C activity. CONCLUSION Survival of the acetylcholinesterase knock-out mouse could be linked to adaptation of many neuronal systems during development including the cholinergic, adrenergic and dopaminergic. These adaptations balance the overstimulation of cholinergic receptors caused by high acetylcholine concentrations and thus maintain homeostasis inside the cell, allowing the animal to live.
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155
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Park JH, Enikolopov G. Transient elevation of adult hippocampal neurogenesis after dopamine depletion. Exp Neurol 2010; 222:267-76. [PMID: 20079351 DOI: 10.1016/j.expneurol.2010.01.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 01/01/2010] [Accepted: 01/06/2010] [Indexed: 12/14/2022]
Abstract
Degeneration of the midbrain dopaminergic neurons during Parkinson's disease (PD) may affect remote regions of the brain that are innervated by the projections of these neurons. The dentate gyrus (DG), a site of continuous production of new neurons in the adult hippocampus, receives dopaminergic inputs from the neurons of the substantia nigra (SN). Thus, depletion of the SN neurons during disease or in experimental settings may directly affect adult hippocampal neurogenesis. We show that experimental ablation of dopaminergic neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydopyridine (MPTP) mouse model of PD results in a transient increase in cell division in the subgranular zone (SGZ) of the DG. This increase is evident for the amplifying neural progenitors and for their postmitotic progeny; our results also indicate that MPTP treatment affects division of the normally quiescent stem cells in the SGZ. We also show that l-DOPA, used in the clinical treatment of PD, while attenuating the MPTP-induced death of dopaminergic neurons, does not alter the effect of MPTP on cell division in the DG. Our results suggest that a decrease in dopaminergic signaling in the hippocampus leads to a transient activation of stem and progenitor cells in the DG.
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Affiliation(s)
- June-Hee Park
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
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156
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Catechol-O-Methyltransferase Inhibitors in Preclinical Models as Adjuncts of l-Dopa Treatment. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 95:191-205. [DOI: 10.1016/b978-0-12-381326-8.00008-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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157
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Neuroprotection in Parkinson's Disease. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/b978-1-4160-6641-5.00018-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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158
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Interaction map and selection of microRNA targets in Parkinson's disease-related genes. J Biomed Biotechnol 2009; 2009:363145. [PMID: 19911064 PMCID: PMC2774487 DOI: 10.1155/2009/363145] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 07/31/2009] [Accepted: 08/11/2009] [Indexed: 12/19/2022] Open
Abstract
Parkinson's disease (PD) is a complex multigenic neurodisorder frequently occurring in elderly persons. To investigate noncoding tiny microRNA mediated gene regulation, miRanda (version 1.0b) was used to predict human miRNA target sites on selected 29 genes related to PD. To verify output generated from miRanda, a similar analysis was performed only for microRNA target sites in 3'UTR using TargetScan (version 5.1). Data extracted by miRanda elucidates the mode of microRNA action based on the location of target sites in the Parkinson genes. Sites prone to action of multiple miRNAs were identified as "hot spots." Important properties of each miRNA including multiplicity and cooperativity appear to contribute towards a complex interplay between miRNAs and their targets. Two sets of predicted results were explored for the occurrence of target sites of 112 miRNAs expressed in midbrain. Overall, convergence of results predicted by two algorithms revealed that 48 target sites for midbrain-specific miRNA occur in close proximity in 9 genes. This study will pave a way for selection of potential miRNA candidates for Parkinson's disease-related genes for quick therapeutic applications and diagnosis.
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160
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Schapira AH, Agid Y, Barone P, Jenner P, Lemke MR, Poewe W, Rascol O, Reichmann H, Tolosa E. Perspectives on recent advances in the understanding and treatment of Parkinson’s disease. Eur J Neurol 2009; 16:1090-9. [DOI: 10.1111/j.1468-1331.2009.02793.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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161
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Zeng BY, Balfour RH, Jackson MJ, Rose S, Jenner P. Expression of catechol-O-methyltransferase in the brain and periphery of normal and MPTP-treated common marmosets. J Neural Transm (Vienna) 2009; 117:45-51. [DOI: 10.1007/s00702-009-0315-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 09/10/2009] [Indexed: 12/28/2022]
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162
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Nicotinic receptors: allosteric transitions and therapeutic targets in the nervous system. Nat Rev Drug Discov 2009; 8:733-50. [PMID: 19721446 DOI: 10.1038/nrd2927] [Citation(s) in RCA: 527] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nicotinic receptors - a family of ligand-gated ion channels that mediate the effects of the neurotransmitter acetylcholine - are among the most well understood allosteric membrane proteins from a structural and functional perspective. There is also considerable interest in modulating nicotinic receptors to treat nervous-system disorders such as Alzheimer's disease, schizophrenia, depression, attention deficit hyperactivity disorder and tobacco addiction. This article describes both recent advances in our understanding of the assembly, activity and conformational transitions of nicotinic receptors, as well as developments in the therapeutic application of nicotinic receptor ligands, with the aim of aiding novel drug discovery by bridging the gap between these two rapidly developing fields.
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163
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Vendrell M, Soriano A, Casadó V, Díaz J, Lavilla R, Canela E, Lluís C, Franco R, Albericio F, Royo M. Indoloquinolizidine-Peptide Hybrids as Multiple Agonists for D1and D2Dopamine Receptors. ChemMedChem 2009; 4:1514-22. [DOI: 10.1002/cmdc.200900149] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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164
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165
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Nissinen H, Kuoppamäki M, Leinonen M, Schapira AH. Early versus delayed initiation of entacapone in levodopa-treated patients with Parkinson's disease: a long-term, retrospective analysis. Eur J Neurol 2009; 16:1305-11. [PMID: 19570145 DOI: 10.1111/j.1468-1331.2009.02726.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND We analysed data from three clinical trials in Parkinson's disease (PD) patients with wearing-off to determine whether early enhancement of levodopa therapy with entacapone can lead to better long-term outcomes than delayed entacapone treatment. METHODS Post-hoc analysis of pooled data from three randomized, double-blind, placebo-controlled studies and their long-term, open-label extension phases. In all three studies, patients on levodopa/dopa-decarboxylase inhibitor (DDCI) were first randomized to entacapone ('early-start' group) or placebo ('delayed-start' group) for the initial 6-month double-blind phase, after which all patients received open-label levodopa/DDCI and entacapone treatment for up to 5 years. RESULTS A total of 488 PD patients with wearing-off were included in the analysis. A statistically significant benefit of early initiation of levodopa/DDCI and entacapone was found, with an improvement in Unified Parkinson's Disease Rating Scale Part III (motor) score of -1.66 (95% confidence intervals [-3.01, -0.31]) points compared with the delayed-start treatment group (P < 0.05). Levodopa/DDCI and entacapone therapy was well tolerated. There was no excess of dyskinesia in the early-start group. CONCLUSIONS These data suggest that early rather than delayed addition of entacapone to levodopa/DDCI in PD patients with wearing-off provides a modest clinical benefit over levodopa/DDCI that is maintained for up to 5 years.
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166
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Quik M, O'Leary K, Tanner CM. Nicotine and Parkinson's disease: implications for therapy. Mov Disord 2009; 23:1641-52. [PMID: 18683238 DOI: 10.1002/mds.21900] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Accumulating evidence suggests that nicotine, a drug that stimulates nicotinic acetylcholine receptors, may be of therapeutic value in Parkinson's disease. Beneficial effects may be several-fold. One of these is a protective action against nigrostriatal damage. This possibility stems from the results of epidemiological studies that consistently demonstrate an inverse correlation between tobacco use and Parkinson's disease. This reduced incidence of Parkinson's disease has been attributed to the nicotine in tobacco products, at least in part, based on experimental work showing a protective effect of nicotine against toxic insults. Second, several studies suggest a symptomatic effect of nicotine in Parkinson's disease, although effects are small and somewhat variable. Third, recent data in nonhuman primates show that nicotine attenuates levodopa-induced dyskinesias, a debilitating side effect that develops in the majority of patients on levodopa therapy. Collectively, these observations suggest that nicotine or CNS selective nicotinic receptor ligands hold promise for Parkinson's disease therapy to reduce disease progression, improve symptoms, and/or decrease levodopa-induced dyskinesias.
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Affiliation(s)
- Maryka Quik
- The Parkinson's Institute, Sunnyvale, California, USA.
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167
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Kalda A, Herm L, Rinken A, Zharkovsky A, Chen JF. Co-administration of the partial dopamine D2 agonist terguride with L-dopa attenuates L-dopa-induced locomotor sensitization in hemiparkinsonian mice. Behav Brain Res 2009; 202:232-7. [PMID: 19463706 DOI: 10.1016/j.bbr.2009.03.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 03/22/2009] [Accepted: 03/28/2009] [Indexed: 11/26/2022]
Abstract
While dopamine replacement remains the standard pharmacotherapy for Parkinson's disease, chronic L-dopa treatment is associated with development of debilitating motor fluctuations such as L-dopa-induced dyskinesia (LID). In this study we evaluated the effects of the partial dopamine D(2) agonist terguride on the development of LID in hemiparkinsonian mice (unilaterally lesioned with 6-hydroxydopamine). First, consistent with the partial agonist property, terguride had 1000-fold higher potency than dopamine, yet producing one-third level of maximal activation of dopamine, as assayed by [(35)S]GTPgammaS binding. Furthermore, in the absence and presence of dopamine in vitro, terguride increased and decreased striatal [(35)S]GTPgammaS binding, respectively. Next, we found that co-administration of terguride (at 0.1 and 0.5mg/kg, i.p.) with L-dopa (1.8 mg/kg) daily for 14 days, significantly attenuated the development and expression of L-dopa-induced rotational sensitization. Furthermore, the cross-challenge paradigm revealed that chronic L-dopa treatment (but not terguride) sensitized locomotor response to the dopamine D(1) agonist SKF 81297 while chronic treatment with terguride (but not L-dopa) produced sensitized locomotor responses to the adenosine A(2A) antagonist 8-(3-chlorostyryl)caffeine (CSC). Importantly, the co-administration of terguride with L-dopa did not show locomotor sensitization to either SFK 81297 or CSC upon challenge. Together, these results suggest that co-administration of partial dopamine D(2) agonists with L-dopa may prophylactically attenuate L-dopa-induced abnormal behavioral responses such as LID.
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Affiliation(s)
- Anti Kalda
- Department of Pharmacology, University of Tartu, Ravila 19, 51014 Tartu, Estonia
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168
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Villoslada P, Steinman L, Baranzini SE. Systems biology and its application to the understanding of neurological diseases. Ann Neurol 2009; 65:124-39. [PMID: 19260029 DOI: 10.1002/ana.21634] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent advances in molecular biology, neurobiology, genetics, and imaging have demonstrated important insights about the nature of neurological diseases. However, a comprehensive understanding of their pathogenesis is still lacking. Although reductionism has been successful in enumerating and characterizing the components of most living organisms, it has failed to generate knowledge on how these components interact in complex arrangements to allow and sustain two of the most fundamental properties of the organism as a whole: its fitness, also termed its robustness, and its capacity to evolve. Systems biology complements the classic reductionist approaches in the biomedical sciences by enabling integration of available molecular, physiological, and clinical information in the context of a quantitative framework typically used by engineers. Systems biology employs tools developed in physics and mathematics such as nonlinear dynamics, control theory, and modeling of dynamic systems. The main goal of a systems approach to biology is to solve questions related to the complexity of living systems such as the brain, which cannot be reconciled solely with the currently available tools of molecular biology and genomics. As an example of the utility of this systems biological approach, network-based analyses of genes involved in hereditary ataxias have demonstrated a set of pathways related to RNA splicing, a novel pathogenic mechanism for these diseases. Network-based analysis is also challenging the current nosology of neurological diseases. This new knowledge will contribute to the development of patient-specific therapeutic approaches, bringing the paradigm of personalized medicine one step closer to reality.
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Affiliation(s)
- Pablo Villoslada
- Department of Neuroscience, Hospital Clinic-Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
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169
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Vernon GM. Parkinson Disease and the Nurse Practitioner: Diagnostic and Management Challenges. J Nurse Pract 2009. [DOI: 10.1016/j.nurpra.2008.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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170
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Przybyla JA, Cueva JP, Chemel BR, Joseph Hsu K, Riese DJ, McCorvy JD, Chester JA, Nichols DE, Watts VJ. Comparison of the enantiomers of (+/-)-doxanthrine, a high efficacy full dopamine D(1) receptor agonist, and a reversal of enantioselectivity at D(1) versus alpha(2C) adrenergic receptors. Eur Neuropsychopharmacol 2009; 19:138-46. [PMID: 19028082 PMCID: PMC2636714 DOI: 10.1016/j.euroneuro.2008.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 09/17/2008] [Accepted: 10/21/2008] [Indexed: 11/20/2022]
Abstract
Parkinson's disease is a neurodegenerative condition involving the death of dopaminergic neurons in the substantia nigra. Dopamine D(1) receptor agonists are potential alternative treatments to current therapies that employ L-DOPA, a dopamine precursor. We evaluated the pharmacological profiles of the enantiomers of a novel dopamine D(1) receptor full agonist, doxanthrine (DOX) at D(1) and alpha(2C) adrenergic receptors. (+)-DOX displayed greater potency and intrinsic activity than (-)-DOX in porcine striatal tissue and in a heterologous D(1) receptor expression system. Studies in MCF7 cells, which express an endogenous human dopamine D(1)-like receptor, revealed that (-)-DOX was a weak partial agonist/antagonist that reduced the functional activity of (+)-DOX and dopamine. (-)-DOX had 10-fold greater potency than (+)-DOX at alpha(2C) adrenergic receptors, with an EC50 value of 4 nM. These findings demonstrate a reversed stereoselectivity for the enantiomers of DOX at D(1) and alpha(2C) receptors and have implications for the therapeutic utility of doxanthrine.
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Affiliation(s)
- Julie A. Przybyla
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Juan P. Cueva
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Benjamin R. Chemel
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - K. Joseph Hsu
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - David J. Riese
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - John D. McCorvy
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Julia A. Chester
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907
| | - David E. Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Val J. Watts
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
- Corresponding author, Purdue University, Dept. of Medicinal Chemistry and Molecular Pharmacology, 575 Stadium Mall Dr., RHPH 210, West Lafayette, IN 47907-2091, Tel. 765-469-3872, Fax. (765) 494-1414,
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Schapira AHV, Olanow CW. Drug selection and timing of initiation of treatment in early Parkinson's disease. Ann Neurol 2009; 64 Suppl 2:S47-55. [DOI: 10.1002/ana.21460] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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172
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Lima MMS, Reksidler ABB, Vital MABF. The neurobiology of the substantia nigra pars compacta: from motor to sleep regulation. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2009:135-45. [PMID: 20411774 DOI: 10.1007/978-3-211-92660-4_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clinical characteristics of Parkinson's disease (PD) are the result of the degeneration of the neurons of the substantia nigra pars compacta (SNpc). Several mechanisms are implicated in the degeneration of nigrostriatal neurons such as oxidative stress, mitochondrial dysfunction, protein misfolding, disturbances of dopamine (DA) metabolism and transport, neuroinflammation, and necrosis/apoptosis. The literature widely explores the neurotoxic models elicited by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA). Because of the models, it is known that basal ganglia, particularly substantia nigra, have been related to a diversity of functions, from motor to sleep regulation. Nevertheless, a current debate concerning the role of DA on the sleep-wake cycle is in progress. In summary, it is suggested that the dopaminergic system is implicated in the physiology of sleep, with particular regard to the influence of the SNpc neurons. The understanding of the functioning and connectivity of the SNpc neurons has become fundamental to discovering the neurobiology of these neurons.
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Affiliation(s)
- Marcelo M S Lima
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis SC 88049-900, Brazil.
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173
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Schapira AH. Neurobiology and treatment of Parkinson's disease. Trends Pharmacol Sci 2009; 30:41-7. [DOI: 10.1016/j.tips.2008.10.005] [Citation(s) in RCA: 173] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 10/17/2008] [Accepted: 10/20/2008] [Indexed: 11/29/2022]
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174
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Abstract
The development of potent and selective agonists and antagonists of adenosine receptors (ARs) has been a target of medicinal chemistry research for several decades, and recently the US Food and Drug Administration has approved Lexiscan, an adenosine derivative substituted at the 2 position, for use as a pharmacologic stress agent in radionuclide myocardial perfusion imaging. Currently, some other adenosine A(2A) receptor (A(2A)AR) agonists and antagonists are undergoing preclinical testing and clinical trials. While agonists are potent antiinflammatory agents also showing hypotensive effects, antagonists are being developed for the treatment of Parkinson's disease.However, since there are still major problems in this field, including side effects, low brain penetration (for the targeting of CNS diseases), short half-life, or lack of in vivo effects, the design and development of new AR ligands is a hot research topic.This review presents an update on the medicinal chemistry of A(2A)AR agonists and antagonists, and stresses the strong need for more selective ligands at the human A(2A)AR subtype, in particular in the case of agonists.
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Affiliation(s)
- Gloria Cristalli
- Dipartimento di Scienze Chimiche, Università di Camerino, 62032 Camerino (MC), Italy.
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175
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Boehmler W, Petko J, Woll M, Frey C, Thisse B, Thisse C, Canfield VA, Levenson R. Identification of zebrafish A2 adenosine receptors and expression in developing embryos. Gene Expr Patterns 2008; 9:144-51. [PMID: 19070682 DOI: 10.1016/j.gep.2008.11.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/20/2008] [Accepted: 11/21/2008] [Indexed: 01/02/2023]
Abstract
The A2A adenosine receptor (AdR) subtype has emerged as an attractive target in the pursuit of improved therapy for Parkinson's disease (PD). This report focuses on characterization of zebrafish a2 AdRs. By mining the zebrafish EST and genomic sequence databases, we identified two zebrafish a2a (adora2a.1 and adora2a.2) genes and one a2b (adora2b) AdR gene. Sequence comparisons indicate that the predicted zebrafish A2 AdR polypeptides share 62-74% amino acid identity to mammalian A2 AdRs. We mapped the adora2a.1 gene to chromosome 8, the adora2a.2 gene to chromosome 21, and the adora2b gene to chromosome 5. Whole mount in situ hybridization analysis indicates zebrafish a2 AdR genes are expressed primarily within the central nervous system (CNS). Zebrafish are known to be sensitive to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a neurotoxin that causes selective loss of dopaminergic neurons and PD-like symptoms in humans as well as in animal models. Here we show that caffeine, an A2A AdR antagonist, is neuroprotective against the adverse effects of MPTP in zebrafish embryos. These results suggest that zebrafish AdRs may serve as useful targets for testing novel therapeutic strategies for the treatment of PD.
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Affiliation(s)
- Wendy Boehmler
- Department of Pharmacology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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176
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Jaakola VP, Griffith MT, Hanson MA, Cherezov V, Chien EYT, Lane JR, Ijzerman AP, Stevens RC. The 2.6 angstrom crystal structure of a human A2A adenosine receptor bound to an antagonist. Science 2008; 322:1211-7. [PMID: 18832607 PMCID: PMC2586971 DOI: 10.1126/science.1164772] [Citation(s) in RCA: 1427] [Impact Index Per Article: 89.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The adenosine class of heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) mediates the important role of extracellular adenosine in many physiological processes and is antagonized by caffeine. We have determined the crystal structure of the human A2A adenosine receptor, in complex with a high-affinity subtype-selective antagonist, ZM241385, to 2.6 angstrom resolution. Four disulfide bridges in the extracellular domain, combined with a subtle repacking of the transmembrane helices relative to the adrenergic and rhodopsin receptor structures, define a pocket distinct from that of other structurally determined GPCRs. The arrangement allows for the binding of the antagonist in an extended conformation, perpendicular to the membrane plane. The binding site highlights an integral role for the extracellular loops, together with the helical core, in ligand recognition by this class of GPCRs and suggests a role for ZM241385 in restricting the movement of a tryptophan residue important in the activation mechanism of the class A receptors.
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Affiliation(s)
- Veli-Pekka Jaakola
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037 USA
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177
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Schapira AHV. Mitochondrial Dysfunction in Neurodegenerative Diseases. Neurochem Res 2008; 33:2502-9. [DOI: 10.1007/s11064-008-9855-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Accepted: 09/13/2008] [Indexed: 12/26/2022]
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178
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Visanji NP, de Bie RMA, Johnston TH, McCreary AC, Brotchie JM, Fox SH. The nociceptin/orphanin FQ (NOP) receptor antagonist J-113397 enhances the effects of levodopa in the MPTP-lesioned nonhuman primate model of Parkinson's disease. Mov Disord 2008; 23:1922-5. [PMID: 18759357 DOI: 10.1002/mds.22086] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
The anti-parkinsonian and levodopa-sparing potential of the nociceptin/orphanin FQ receptor (NOP) antagonist J-113397 has been demonstrated in rodent models of Parkinson's disease. Here, we describe the levodopa-sparing potential of J-113397 in MPTP-lesioned marmosets. Coadministration of J-113397 (30 mg/kg) with a sub-therapeutic dose of levodopa (12.5 mg/kg) produced an anti-parkinsonian action equivalent to that of a therapeutic dose of levodopa. However, these effects were accompanied by an equivalent level of dyskinesia. The actions of NOP antagonists seen in rodents translate to nonhuman primates. However, the present study raises the possibility that these levodopa-sparing benefits may be offset by a propensity to exacerbate dyskinesia.
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179
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Perez CA, Tong Y, Guo M. Iron Chelators as Potential Therapeutic Agents for Parkinson's Disease. ACTA ACUST UNITED AC 2008; 4:150-158. [PMID: 19809592 DOI: 10.2174/157340708786305952] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parkinson's disease (PD) is a neurological disorder characterized by the progressive impairment of motor skills in patients. Growing evidence suggests that abnormal redox-active metal accumulation, caused by dysregulation, plays a central role in the neuropathology of PD. Redox-active metals (e.g. Fe and Cu) catalyze essential reactions for brain function. However, these metals can also participate in the generation of highly toxic free radicals that can cause oxidative damage to cells and ultimately lead to the death of dopamine-containing neurons. The emergence of redox-active metals as key players in the pathogenesis of PD strongly suggests that metal-chelators could be beneficial in the treatment of this condition. This mini-review summarizes major recent developments on natural, synthetic iron chelating compounds and hydrogen peroxide-triggered prochelators as potential candidates for PD treatment.
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Affiliation(s)
- Carlos A Perez
- Department of Chemistry and Biochemistry, University of Massachusetts, Dartmouth, MA 02747-2300
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180
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Lane EL, Handley OJ, Rosser AE, Dunnett SB. Potential cellular and regenerative approaches for the treatment of Parkinson's disease. Neuropsychiatr Dis Treat 2008; 4:835-45. [PMID: 19183776 PMCID: PMC2626922 DOI: 10.2147/ndt.s2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Parkinson's disease is most commonly treated with a range of pharmacotherapeutics, with the more recent introduction of surgical techniques including deep-brain stimulation. These have limited capabilities to improve symptoms of the disease in more advanced stages, thus new therapeutic strategies including the use of viral vectors and stem cells are in development. Providing a continuous supply of dopamine to the striatum in an attempt to improve the treatment of motor symptoms using enzymes in the dopamine synthesis and machinery is one approach. Alternatively, there are tools which may serve to both protect and encourage outgrowth of surviving neurons using growth factors or to directly replace lost innervation by transplantation of primary tissue or stem cell-derived dopaminergic neurons. We summarize some of the potential therapeutic approaches and also consider the recent EU directives on practical aspects of handling viral vectors, cells and tissues, and in the running of clinical trials in Europe which impact on their development.
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Affiliation(s)
- Emma L Lane
- Brain Repair Group, School of Biosciences, Cardiff University, CF10 3US, UK
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181
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Jenner P. Preventing and controlling dyskinesia in Parkinson's disease-A view of current knowledge and future opportunities. Mov Disord 2008; 23 Suppl 3:S585-98. [DOI: 10.1002/mds.22022] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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182
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Giorgi M, D'Angelo V, Esposito Z, Nuccetelli V, Sorge R, Martorana A, Stefani A, Bernardi G, Sancesario G. Lowered cAMP and cGMP signalling in the brain during levodopa-induced dyskinesias in hemiparkinsonian rats: new aspects in the pathogenetic mechanisms. Eur J Neurosci 2008; 28:941-50. [PMID: 18717735 DOI: 10.1111/j.1460-9568.2008.06387.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Dysregulation of dopamine receptors is thought to underlie levodopa-induced dyskinesias in experimental models of Parkinson's disease. It is unknown whether an imbalance of the second messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is involved in the alterations of levodopa/dopamine signal transduction. We examined cAMP and cGMP signalling in the interconnected cortico-striatal-pallidal loop at the peak of levodopa-induced dyskinesias in rats with 6-hydroxydopamine lesions in the substantia nigra. In addition, we examined the role of phosphodiesterase (PDE) and the rate of cAMP and cGMP degradation on the severity of levodopa-induced dyskinesias in animals pretreated with PDE inhibitor, zaprinast. Unilateral lesion of substantia nigra led to an increase in cAMP but a decrease in cGMP levels in the ipsilateral basal ganglia. After chronic levodopa treatment, cAMP and cGMP were differentially regulated in eukinetic animals: the cAMP level increased in the cortex and striatum but decreased in the globus pallidus of both hemispheres, whereas the cGMP decreased below baseline levels in the contralateral cortico-striatal-pallidal regions. In dyskinetic animals chronic levodopa treatment led to an absolute decrease in cAMP and cGMP levels in cortico-striatal-pallidal regions of both hemispheres. Pretreatment with zaprinast reduced the severity of levodopa-induced dyskinesias, and partly prevented the decrease in cyclic nucleotides compared with pretreatment with saline-levodopa. In conclusion, using a rat model of hemiparkinsonism, we observed a significant reduction in the levels of cyclic nucleotides in both hemispheres at the peak of levodopa-induced dyskinesias. We propose that such a decrease in cyclic nucleotides may partly result from increased catabolism through PDE overactivity.
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Affiliation(s)
- M Giorgi
- Department of Basic and Applied Biology, L'Aquila University, L'Aquila, Italy
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183
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Heat shock protein 90 modulates LRRK2 stability: potential implications for Parkinson's disease treatment. J Neurosci 2008; 28:6757-9. [PMID: 18596151 DOI: 10.1523/jneurosci.1870-08.2008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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184
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Current Management of the Cognitive Dysfunction in Parkinson’s Disease: How Far Have We Come? Exp Biol Med (Maywood) 2008; 233:941-51. [DOI: 10.3181/0707-mr-193] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Parkinson’s disease (PD) clinical features comprise both motor and nonmotor manifestations. Among the nonmotor complications, dementia is the most important. Approximately 40% of PD patients are affected by cognitive impairment. Remarkably, in addition to age, dementia is an independent predictor of mortality, whereas age at onset of PD and severity of neurological symptoms are not. In this review, I summarize the current knowledge of the pathogenesis of the PD cognitive impairment in relation to the therapies presently accessible and those that could become strategic in the near future. It is hypothesized that patients with PD show two components of cognitive dysfunction (CD): a generalized profile of subcortical dementia (PDsCD), and an overlapped pattern suggesting specific prefrontal damage with CD (PDpFCD). PDsCD is associated with structural neocortical/subcortical changes in the brain (in frontal, parietal, limbic, and temporal lobes, as well as in midbrain structures). In PDpFCD cognitive deficits comprise impairments in neuropsychological tests sensitive for frontal lobe function (discrete elements of episodic and working memory for instance), which are considered to be the consequence of dysfunction in neuronal loops connecting the prefrontal cortex and basal ganglia. Drugs reviewed for targeting PDsCD include: cholinesterase inhibitors, agents with mixed cholinergic and dopaminergic properties, antiglutamatergic drugs, mixed antiglutamatergic/dopaminergic agents; antioxidants and enhancers of mitochondrial functions, and anti-COX-2, as well as other anti-inflammatory mediators. Preliminary studies with vehicles that may target PDpFCD include piribedil, tolcapone, amantadine, and farampator. Additional agents (citicoline and neuroimmuniphilines, among others) will be outlined. A brief overview on neuroprotection and promising new biological advances in PD (deep brain stimulation, stem cells, gene therapy) also will be summarized.
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185
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186
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Berg KA, Clarke WP, Cunningham KA, Spampinato U. Fine-tuning serotonin2c receptor function in the brain: molecular and functional implications. Neuropharmacology 2008; 55:969-76. [PMID: 18602407 DOI: 10.1016/j.neuropharm.2008.06.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 06/05/2008] [Accepted: 06/09/2008] [Indexed: 10/21/2022]
Abstract
The serotonin(2C) receptor (5-HT(2C)R) is a member of the serotonin(2) family of 7-transmembrane-spanning (7-TMS) receptors, which possesses unique molecular and pharmacological properties such as constitutive activity and RNA editing. The 5-HT(2C)R is widely expressed within the central nervous system, where is thought to play a major role in the regulation of neuronal network excitability. In keeping with its ability to modulate dopamine (DA) neuron function in the brain, the 5-HT(2C)R is currently considered as a major target for improved treatments of neuropsychiatric disorders related to DA neuron dysfunction, such as depression, schizophrenia, Parkinson's disease or drug addiction. The aim of this review is to provide an update of the functional status of the central 5-HT(2C)R, covering molecular, cellular, anatomical, biochemical and behavioral aspects to highlight its distinctive regulatory properties, the emerging functional significance of constitutive activity and RNA editing in vivo, and the therapeutic potential of inverse agonism.
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Affiliation(s)
- Kelly A Berg
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA
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187
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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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188
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Neurokinin B/NK3 receptors exert feedback inhibition on l-DOPA actions in the 6-OHDA lesion rat model of Parkinson's disease. Neuropharmacology 2008; 54:1143-52. [DOI: 10.1016/j.neuropharm.2008.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 03/10/2008] [Accepted: 03/11/2008] [Indexed: 11/24/2022]
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189
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Iravani MM, Sadeghian M, Leung CCM, Tel BC, Rose S, Schapira AH, Jenner P. Continuous subcutaneous infusion of pramipexole protects against lipopolysaccharide-induced dopaminergic cell death without affecting the inflammatory response. Exp Neurol 2008; 212:522-31. [PMID: 18571649 DOI: 10.1016/j.expneurol.2008.04.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 04/02/2008] [Accepted: 04/30/2008] [Indexed: 12/27/2022]
Abstract
The D2/D3 dopamine receptor agonist pramipexole, protects against toxin-induced dopaminergic neuronal destruction but its mechanism of action is unknown. Inflammation following glial cell activation contributes to cell death in Parkinson's disease and we now report on the effects of acute or chronic administration of pramipexole on lipopolysaccharide (LPS) induced inflammation and nigral dopaminergic cell death in the rat. At 48 h and 30 days following supranigral administration of LPS, approximately 70% of tyrosine hydroxylase (TH) immunoreactive (-ir) cells in substantia nigra had degenerated with a corresponding loss of TH-ir terminals in the striatum. In rats acutely treated with pramipexole (2x1 mg/kg; s.c.) 48 h following LPS application, there was no difference in the number of TH-ir cells or terminals compared to LPS-treated rats receiving vehicle. However, the continuous subcutaneous infusion of pramipexole for 7 days prior to LPS and 21 days subsequently, produced a marked preservation of both TH-ir cells and terminals. At 48 h or 30 days, LPS induced an up-regulation of ubiquitin-ir within the nigral TH-ir neurones, which was reduced by pramipexole treatment. Thirty days following supranigral LPS administration (9 days after the end of infusion), (+)-amphetamine (5 mg/kg, i.p.) caused robust ipsiversive rotation. In rats treated with LPS but receiving continuous subcutaneous administration of pramipexole, (+)-amphetamine-induced rotation was markedly reduced. LPS-induced increase in the levels of inflammatory markers, were not affected by either acute administration or continuous infusion of pramipexole. Continuous infusion of pramipexole protected dopaminergic neurones against inflammation induced degeneration but without modification of the inflammatory response.
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Affiliation(s)
- Mahmoud M Iravani
- Neurodegenerative Disease Research Centre, School of Health and Biomedical Sciences, King's College, London SE1 1UL, UK
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190
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Ward RJ, Lallemand F, de Witte P, Dexter DT. Neurochemical pathways involved in the protective effects of nicotine and ethanol in preventing the development of Parkinson's disease: potential targets for the development of new therapeutic agents. Prog Neurobiol 2008; 85:135-47. [PMID: 18482793 DOI: 10.1016/j.pneurobio.2008.03.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 01/07/2008] [Accepted: 03/18/2008] [Indexed: 12/26/2022]
Abstract
In this short review, neurochemical targets are identified where nicotine, and possibly ethanol, may interact to prevent the occurrence of Parkinson's disease. These are (a) the nicotinic acetycholine receptors present in the nigrostriatal area or on the surface of microglia, (b) monoamine oxidases and (c) inducible nitric oxide synthase. If such induced changes can be verified in clinical studies, this may help in the design of new therapeutic drugs which may be of relevance to diminish the incidence and perhaps the progression of the debilitating condition of Parkinson's disease.
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Affiliation(s)
- Roberta J Ward
- Laboratoire de Biologie du Comportement, Université Catholique de Louvain, 1 Croix du Sud, 1348 Louvain-la-Neuve, Belgium.
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191
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Lee J, Gomez-Ramirez J, Johnston TH, Visanji N, Brotchie JM. Receptor-activity modifying protein 1 expression is increased in the striatum following repeated L-DOPA administration in a 6-hydroxydopamine lesioned rat model of Parkinson's disease. Synapse 2008; 62:310-3. [DOI: 10.1002/syn.20481] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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192
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Zahodne LB, Fernandez HH. Course, prognosis, and management of psychosis in Parkinson's disease: are current treatments really effective? CNS Spectr 2008; 13:26-33. [PMID: 18323764 PMCID: PMC3045851 DOI: 10.1017/s1092852900017296] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
It is essential to recognize and treat psychosis in Parkinson's disease for several reasons. Studies have shown that psychosis in Parkinson's disease patients is a strong risk factor for nursing home placement. Psychosis may be the greatest source of stress for caretakers of Parkinson's patients; it is often persistent, and its presence markedly increases mortality. Treatment of psychotic symptoms should occur only after potential medical and environmental causes of delirium have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's antiparkinsonian medications to those that are necessary to preserve motor function. Should that fail, an atypical antipsychotic is presently the treatment of choice. An emerging treatment option is acetylcholinesterase inhibitors. This article reviews what is currently known about the course, prognosis, and treatment strategies in Parkinson's disease psychosis.
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Affiliation(s)
- Laura B. Zahodne
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL
- Department of Neurology, University of Florida/McKnight Brain Institute, Gainesville, FL
| | - Hubert H. Fernandez
- Department of Neurology, University of Florida/McKnight Brain Institute, Gainesville, FL
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193
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Nyholm D, Lennernäs H. Irregular gastrointestinal drug absorption in Parkinson's disease. Expert Opin Drug Metab Toxicol 2008; 4:193-203. [DOI: 10.1517/17425255.4.2.193] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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194
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Zezula J, Freissmuth M. The A(2A)-adenosine receptor: a GPCR with unique features? Br J Pharmacol 2008; 153 Suppl 1:S184-90. [PMID: 18246094 DOI: 10.1038/sj.bjp.0707674] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The A(2A)-adenosine receptor is a prototypical G(s)-coupled receptor. However, the A(2A)-receptor has several structural and functional characteristics that make it unique. In contrast to the classical model of collision coupling described for the beta-adrenergic receptors, the A(2A)-receptor couples to adenylyl cyclase by restricted collision coupling and forms a tight complex with G(s). The mechanistic basis for this is not clear; restricted collision coupling may arise from the interaction of the receptor with additional proteins or due to the fact that G protein-coupling is confined to specialized membrane microdomains. The A(2A)-receptor has a long C-terminus (of >120 residues), which is for the most part dispensable for coupling to G(s). It was originally viewed as the docking site for kinases and the beta-arrestin family to initiate receptor desensitization and endocytosis. The A(2A)-receptor is, however, fairly resistant to agonist-induced internalization. Recently, the C-terminus has also been appreciated as a binding site for several additional 'accessory' proteins. Established interaction partners include alpha-actinin, ARNO, USP4 and translin-associated protein-X. In addition, the A(2A)-receptor has also been reported to form a heteromeric complex with the D(2)-dopamine receptor and the metabotropic glutamate receptor-5. It is clear that (i) this list cannot be exhaustive and (ii) that all these proteins cannot bind simultaneously to the receptor. There must be rules of engagement, which allow the receptor to elicit different biological responses, which depend on the cellular context and the nature of the concomitant signal(s). Thus, the receptor may function as a coincidence detector and a signal integrator.
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Affiliation(s)
- J Zezula
- Center of Biomolecular Medicine and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Austria
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195
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Pharmacological treatment of Parkinson's disease: life beyond dopamine D2/D3 receptors? J Neural Transm (Vienna) 2008; 115:431-41. [PMID: 18250954 DOI: 10.1007/s00702-007-0852-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
Parkinson's disease (PD) is a multisystemic disorder in which several neurotransmitters other than dopamine are affected. Drugs acting on non-dopaminergic systems are envisaged as promising agents to treat PD and levodopa-induced dyskinesias (LID). However, compounds targeting glutamate, adenosine, noradrenaline, 5-hydroxytryptamine, cannabinoid, and opioid transmitter systems have been assessed in human studies showing negative, inconsistent or unsatisfactory results. Most of these drugs had been tested previously in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned monkeys, as well as in the classic 6-hydroxydopamine-lesioned rat model. These failures raise several questions and concerns about the true reliability of animal studies, the adequacy of the working hypotheses and design of clinical trials, the validity of tools in current use to evaluate a particular effect, and the selectivity of the drugs used. More importantly, observed discrepancies between the results in models and patients, could challenge the validity of current ideas about the pathophysiology of parkinsonism and LID.
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196
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Sachse KT, Jackson EK, Wisniewski SR, Gillespie DG, Puccio AM, Clark RSB, Dixon CE, Kochanek PM. Increases in cerebrospinal fluid caffeine concentration are associated with favorable outcome after severe traumatic brain injury in humans. J Cereb Blood Flow Metab 2008; 28:395-401. [PMID: 17684518 PMCID: PMC3714395 DOI: 10.1038/sj.jcbfm.9600539] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Caffeine, the most widely consumed psychoactive drug and a weak adenosine receptor antagonist, can be neuroprotective or neurotoxic depending on the experimental model or neurologic disorder. However, its contribution to pathophysiology and outcome in traumatic brain injury (TBI) in humans is undefined. We assessed serial cerebrospinal fluid (CSF) concentrations of caffeine and its metabolites (theobromine, paraxanthine, and theophylline) by high-pressure liquid chromatography/ultraviolet in 97 ventricular CSF samples from an established bank, from 30 adults with severe TBI. We prospectively selected a threshold caffeine level of > or = 1 micromol/L (194 ng/mL) as clinically significant. Demographics, Glasgow Coma Scale (GCS) score, admission blood alcohol level, and 6-month dichotomized Glasgow Outcome Scale (GOS) score were assessed. Mean time from injury to initial CSF sampling was 10.77+/-3.13 h. On initial sampling, caffeine was detected in 24 of 30 patients, and the threshold was achieved in 9 patients. Favorable GOS was seen more often in patients with CSF caffeine concentration > or = versus < the threshold (55.6 versus 11.8%, P=0.028). Gender, age, admission CGS score, admission blood alcohol level, and admission systolic arterial blood pressure did not differ between patients with CSF caffeine concentration > or = versus < the threshold. Increases in CSF concentrations of the caffeine metabolites theobromine and paraxanthine were also associated with favorable outcome (P=0.018 and 0.056, respectively). Caffeine and its metabolites are commonly detected in CSF in patients with severe TBI and in an exploratory assessment are associated with favorable outcome. We speculate that caffeine may be neuroprotective by long-term upregulation of adenosine A1 receptors or acute inhibition of A2a receptors.
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Affiliation(s)
- Kathleen T Sachse
- Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA
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197
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Di Napoli M, Shah IM, Stewart DA. Molecular pathways and genetic aspects of Parkinson's disease: from bench to bedside. Expert Rev Neurother 2008; 7:1693-729. [PMID: 18052765 DOI: 10.1586/14737175.7.12.1693] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Idiopathic Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by dopaminergic neuronal loss within the substantia nigra. The incidence and prevalence of PD is rising with an increasing aging population. PD is a slowly progressive condition and patients can develop debilitating motor and functional impairment. Current research has implicated oxidative stress, alpha-synucleinopathy and dysfunction of the ubiquitin-proteasome system in the pathogenesis of PD. A number of gene mutations have also been linked to the development of PD. The elucidation of these new molecular pathways has increased our knowledge of PD pathophysiology. This article reviews important molecular mechanisms and genetic causes implicated in the pathogenesis of PD, which has led to new areas of therapeutic drug research.
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Affiliation(s)
- Mario Di Napoli
- Neurological Service, San Camillo de'Lellis General Hospital, I-2100 Rieti, Italy.
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198
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The cholinergic mesopontine tegmentum is a relatively neglected nicotinic master modulator of the dopaminergic system: relevance to drugs of abuse and pathology. Br J Pharmacol 2008; 153 Suppl 1:S438-45. [PMID: 18223661 DOI: 10.1038/bjp.2008.5] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The mammalian mesopontine tegmentum (MPT) contains two cholinergic nuclei, the pedunculopontine tegmental nucleus (PPTg) and the laterodorsal tegmental nucleus (LDTg). These provide the cholinergic innervation of, among other brain areas, the dopaminergic A9 and A10 cell groups. Their axons are thus the source of endogenous acetylcholine (ACh) acting on somato-dendritic acetylcholine receptors in the substantia nigra (SN) and ventral tegmental area (VTA). The anatomy, physiology, functional and pathological implications of these interactions with the nicotinic subtype of acetylcholine receptors (nAChRs) are discussed with a view of the important role of the MPT as a master regulator of nicotinic dopaminergic signalling in the brain, including for nicotine addiction.
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199
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Di Stefano A, Sozio P, Cerasa LS. Antiparkinson prodrugs. Molecules 2008; 13:46-68. [PMID: 18259129 PMCID: PMC6244951 DOI: 10.3390/molecules13010046] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 01/11/2008] [Accepted: 01/11/2008] [Indexed: 11/29/2022] Open
Abstract
Parkinson’s disease (PD) is a progressive, neurodegenerative disorder which involves the loss of dopaminergic neurons of the substantia nigra pars compacta. Current therapy is essentially symptomatic, and L-Dopa (LD), the direct precursor of dopamine (DA), is the treatment of choice in more advanced stages of the disease. Substitution therapy with LD is, however, associated with a number of acute problems. The peripheral conversion of LD by amino acid decarboxylase (AADC) to DA is responsible for the typical gastrointestinal (nausea, emesis) and cardiovascular (arrhythmia, hypotension) side effects. To minimize the conversion to DA outside the central nervous system (CNS) LD is usually given in combination with peripheral inhibitors of AADC (carbidopa and benserazide). In spite of that, other central nervous side effects such as dyskinesia, on-off phenomenon and end-of-dose deterioration still remain. The main factors responsible for the poor bioavailability and the wide range of inter- and intra-patient variations of plasma levels are the drug’s physical-chemical properties: low water and lipid solubility, resulting in unfavourable partition, and the high susceptibility to chemical and enzymatic degradation. In order to improve the bioavailability, the prodrug approach appeared to be the most promising and some LD prodrugs have been prepared in an effort to solve these problems. We report here a review of progress in antiparkinson prodrugs, focusing on chemical structures mainly related to LD, DA and dopaminergic agonists.
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Affiliation(s)
- Antonio Di Stefano
- Department of Drug Sciences, G. d'Annunzio University, School of Pharmacy, Via dei Vestini 31, 66100 Chieti, Italy.
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200
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Baraldi PG, Tabrizi MA, Gessi S, Borea PA. Adenosine Receptor Antagonists: Translating Medicinal Chemistry and Pharmacology into Clinical Utility. Chem Rev 2008; 108:238-63. [DOI: 10.1021/cr0682195] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Pier Giovanni Baraldi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Mojgan Aghazadeh Tabrizi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Stefania Gessi
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
| | - Pier Andrea Borea
- Departments of Pharmaceutical Sciences and Clinical and Experimental Medicine, Pharmacology Unit and Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Italy
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