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Sharshar T, Porcher R, Asfar P, Grimaldi L, Jabot J, Argaud L, Lebert C, Bollaert PE, Harlay ML, Chillet P, Maury E, Santoli F, Blanc P, Sonneville R, Vu DC, Rohaut B, Mazeraud A, Alvarez JC, Navarro V, Clair B, Outin H, Azabou E, Beloncle F, Ben-Hadj O, Blanc P, Bollaert PE, Bolgert F, Bouadma L, Chillet P, Clair B, Corne P, Clere-Jehl R, Cour M, Crespel A, Déiler V, Dellamonica J, Demeret S, Harley ML, Henry-Lagarrigue M, Jabot J, Heming N, Hernu R, Kouatchet A, Lebert C, Lerolle N, Maury E, Letrou S, Mazeraud A, Mercat A, Mortaza S, Mourvillier B, Outin H, Paugham-Burtz C, Pierrot M, Provent M, Rohaut B, De La Salle S, Santoli F, Schenk M, Siami S, Souday V, Sharshar T, Sonneville R, Timsit JF, Thuong M, Weiss N. Valproic acid as adjuvant treatment for convulsive status epilepticus: a randomised clinical trial. Crit Care 2023; 27:8. [PMID: 36624526 PMCID: PMC9830759 DOI: 10.1186/s13054-022-04292-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Generalised convulsive status epilepticus (GCSE) is a medical emergency. Guidelines recommend a stepwise strategy of benzodiazepines followed by a second-line anti-seizure medicine (ASM). However, GCSE is uncontrolled in 20-40% patients and is associated with protracted hospitalisation, disability, and mortality. The objective was to determine whether valproic acid (VPA) as complementary treatment to the stepwise strategy improves the outcomes of patients with de novo established GCSE. METHODS This was a multicentre, double-blind, randomised controlled trial in 244 adults admitted to intensive care units for GCSE in 16 French hospitals between 2013 and 2018. Patients received standard care of benzodiazepine and a second-line ASM (except VPA). Intervention patients received a 30 mg/kg VPA loading dose, then a 1 mg/kg/h 12 h infusion, whilst the placebo group received an identical intravenous administration of 0.9% saline as a bolus and continuous infusion. Primary outcome was proportion of patients discharged from hospital by day 15. The secondary outcomes were seizure control, adverse events, and cognition at day 90. RESULTS A total of 126 (52%) and 118 (48%) patients were included in the VPA and placebo groups. 224 (93%) and 227 (93%) received a first-line and a second-line ASM before VPA or placebo infusion. There was no between-group difference for patients hospital-discharged at day 15 [VPA, 77 (61%) versus placebo, 72 (61%), adjusted relative risk 1.04; 95% confidence interval (0.89-1.19); p = 0.58]. There were no between-group differences for secondary outcomes. CONCLUSIONS VPA added to the recommended strategy for adult GCSE is well tolerated but did not increase the proportion of patients hospital-discharged by day 15. TRIAL REGISTRATION NO NCT01791868 (ClinicalTrials.gov registry), registered: 15 February 2012.
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Affiliation(s)
- Tarek Sharshar
- grid.508487.60000 0004 7885 7602Neuro-Intensive Care Medicine, Anaesthesiology and ICU Department, GHU-Psychiatry and Neurosciences, Pole Neuro, Sainte-Anne Hospital, Institute of Psychiatry and Neurosciences of Paris, INSERM U1266, Université Paris Cité, Paris, France
| | - Raphaël Porcher
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and StatisticS (CRESS), F-75004 Paris, France ,grid.411394.a0000 0001 2191 1995Centre d’Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France
| | - Pierre Asfar
- grid.411147.60000 0004 0472 0283Department of Medical Intensive Care, University Hospital, Angers, France
| | - Lamiae Grimaldi
- grid.50550.350000 0001 2175 4109Clinical Research Unit, Assistance Publique - Hôpitaux de Paris University Paris-Saclay. Faculty of medicine, University of Versailles Saint-Quentin en Yvelines. Inserm U1018 Team Anti-infective evasion and pharmacoepidemiology, Boulogne-Billancourt, France
| | - Julien Jabot
- Medical-Surgical Intensive Care Unit, CHU Felix-Guyon, Saint-Denis, La Réunion, France
| | - Laurent Argaud
- grid.412180.e0000 0001 2198 4166Service de Médecine Intensive-Réanimation, Hospices Civils de Lyon, Hôpital Edouard Herriot, Lyon, France
| | - Christine Lebert
- grid.477015.00000 0004 1772 6836Médecine Intensive Réanimation, Centre Hospitalier Départemental de Vendée, La Roche-sur-Yon, France
| | - Pierre-Edouard Bollaert
- grid.29172.3f0000 0001 2194 6418CHRU-Nancy, Service de Médecine Intensive Réanimation, Université de Lorraine, 54000 Nancy, France
| | - Marie Line Harlay
- grid.412201.40000 0004 0593 6932Médecine Intensive Réanimation, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Patrick Chillet
- Service de Médecine Intensive - Réanimation, Centre hospitalier Léon Bourgeois, Châlons en Champagne, France
| | - Eric Maury
- grid.462844.80000 0001 2308 1657Service de Médecine Intensive et Réanimation Hôpital Saint-Antoine, Paris-Sorbonne Université, Paris, France
| | - Francois Santoli
- grid.414308.a0000 0004 0594 0368Médecine Intensive—Réanimation, Centre Hospitalier Robert Ballanger, Aulnay sous Bois, France
| | - Pascal Blanc
- grid.440383.80000 0004 1765 1969Réanimation Médico Chirurgicale, Centre Hospitalier René Dubos, Pontoise, France
| | - Romain Sonneville
- Université de Paris Cité, INSERM UMR1137, Paris, France ,grid.411119.d0000 0000 8588 831XAPHP Nord, Médecine Intensive – Réanimation, Hôpital Bichat—Claude Bernard, Paris, France
| | - Dinh Chuyen Vu
- General Intensive Care Unit, Sud-Essonne Hospital, Etampes, France
| | - Benjamin Rohaut
- grid.462844.80000 0001 2308 1657Department of Neurology, Neuro-ICU & Brain institute - ICM, Pitié-Salpêtrière Hospital APHP, Sorbonne Université, Paris, France
| | - Aurelien Mazeraud
- grid.508487.60000 0004 7885 7602Anaesthesiology and ICU Department, GHU-Psychiatry and Neurosciences, Pole Neuro, Sainte-Anne Hospital, Perception and Memory Unit, Neurosciences Department, Institut Pasteur, Université Paris Cité, Paris, France
| | - Jean-Claude Alvarez
- grid.12832.3a0000 0001 2323 0229Department of Pharmacology and Toxicology, Inserm U-1173, Raymond Poincare Hospital, AP-HP, Versailles Saint-Quentin-en-Yvelines University, Paris-Saclay University, 104 Boulevard Raymond Poincare, 92380 Garches, France
| | - Vincent Navarro
- grid.425274.20000 0004 0620 5939AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, Sorbonne Université, and Paris Brain Institute, Paris, France
| | - Bernard Clair
- grid.12832.3a0000 0001 2323 0229General Intensive Care Unit, APHP, Raymond Poincaré Hospital, University of Versailles Saint-Quentin en Yvelines, Garches, France
| | - Hervé Outin
- grid.418056.e0000 0004 1765 2558Intensive Care Unit Centre Hospitalier Intercommunal, Poissy/Saint-Germain-en-Laye, France
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La Rosa C, Ghibaudi M, Bonfanti L. Newly Generated and Non-Newly Generated "Immature" Neurons in the Mammalian Brain: A Possible Reservoir of Young Cells to Prevent Brain Aging and Disease? J Clin Med 2019; 8:jcm8050685. [PMID: 31096632 PMCID: PMC6571946 DOI: 10.3390/jcm8050685] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 01/21/2023] Open
Abstract
Brain plasticity is important for translational purposes since most neurological disorders and brain aging problems remain substantially incurable. In the mammalian nervous system, neurons are mostly not renewed throughout life and cannot be replaced. In humans, the increasing life expectancy explains the increase in brain health problems, also producing heavy social and economic burden. An exception to the “static” brain is represented by stem cell niches leading to the production of new neurons. Such adult neurogenesis is dramatically reduced from fish to mammals, and in large-brained mammals with respect to rodents. Some examples of neurogenesis occurring outside the neurogenic niches have been reported, yet these new neurons actually do not integrate in the mature nervous tissue. Non-newly generated, “immature” neurons (nng-INs) are also present: Prenatally generated cells continuing to express molecules of immaturity (mostly shared with the newly born neurons). Of interest, nng-INs seem to show an inverse phylogenetic trend across mammals, being abundant in higher-order brain regions not served by neurogenesis and providing structural plasticity in rather stable areas. Both newly generated and nng-INs represent a potential reservoir of young cells (a “brain reserve”) that might be exploited for preventing the damage of aging and/or delay the onset/reduce the impact of neurological disorders.
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Affiliation(s)
- Chiara La Rosa
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy.
- Department of Veterinary Sciences, University of Turin, 10095 Torino, Italy.
| | - Marco Ghibaudi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy.
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy.
- Department of Veterinary Sciences, University of Turin, 10095 Torino, Italy.
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Orczyk JJ, Garraghty PE. The effects of ethosuximide on aversive instrumental learning in adult rats. Epilepsy Behav 2018; 84:1-9. [PMID: 29730499 DOI: 10.1016/j.yebeh.2018.03.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 12/29/2022]
Abstract
Antiepileptic medications are the frontline treatment for seizure conditions but are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin-, carbamazepine-, valproic acid-, and felbamate-treated rats. In this experiment, the effects found in ethosuximide (ETH)-treated rats have been compared with those in water-treated controls (controls) using the same instrumental training tasks. Rats treated with ETH did not display any performance deficits in any of the conditions tested relative to controls. These animals showed more rapid acquisition of the avoidance response than the control animals but only when they had prior experience in the appetitive condition. Of the drugs tested to date with these learning paradigms, ETH is the only one that did not impair performance relative to controls in any condition tested. Moreover, in comparison with rats treated with valproic acid, the only other available compound commonly recommended for the treatment of absence seizures, ETH-treated rats show substantially higher performance.
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Affiliation(s)
- John J Orczyk
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA.
| | - Preston E Garraghty
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA; Program in Neuroscience, Indiana University, Bloomington, IN, USA.
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Orczyk JJ, Garraghty PE. The effects of felbamate on appetitive and aversive instrumental learning in adult rats. Epilepsy Behav 2018; 78:14-19. [PMID: 29161629 DOI: 10.1016/j.yebeh.2017.10.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 12/19/2022]
Abstract
Antiepileptic medications are the frontline treatment for seizure conditions but are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin-, carbamazepine-, and valproate-treated rats. In the present experiment, the effects of felbamate (FBM) have been compared to water-treated controls (controls) using the same instrumental training tasks employed here. Rats treated with FBM displayed a deficit in acquiring a tone-signaled avoidance response, relative to controls, but this was true only if they had no prior appetitive experience. Terminal avoidance behavior was equivalent to healthy controls. In contrast, the FBM-treated rats showed enhanced acquisition of the avoidance response relative to controls when given the benefit of prior experience in the appetitive condition. Relative to animals treated with phenytoin, carbamazepine, or valproate, FBM-treated rats showed the lowest overall pattern of deficits using these instrumental learning tasks. While FBM treatment has been severely restricted because of rather low risks of serious medical side effects, we suggest that the risks are not substantially higher than those shown to exist for phenytoin, carbamazepine, or valproate. As psychologists, we further suggest that negative cognitive deficits associated with these various drugs, along with their quality-of-life costs, are of relevance in the design of treatment strategies for individuals with seizure disorders.
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Affiliation(s)
- John J Orczyk
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Preston E Garraghty
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA; Program in Neuroscience, Indiana University, Bloomington, IN, USA.
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Giménez De Béjar V, Caballero Bleda M, Popović N, Popović M. Verapamil Blocks Scopolamine Enhancement Effect on Memory Consolidation in Passive Avoidance Task in Rats. Front Pharmacol 2017; 8:566. [PMID: 28878678 PMCID: PMC5572412 DOI: 10.3389/fphar.2017.00566] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/09/2017] [Indexed: 12/20/2022] Open
Abstract
Our recent data have indicated that scopolamine, a non-selective muscarinic receptor antagonist, improves memory consolidation, in a passive avoidance task, tested in rats. It has been found that verapamil, a phenylalkylamine class of the L-type voltage-dependent calcium channel antagonist, inhibits [3H] N-methyl scopolamine binding to M1 muscarinic receptors. However, there are no data about the effect of verapamil on memory consolidation in the passive avoidance task, in rats. The purpose of the present study was to examine the effects of verapamil (0.5, 1.0, 2.5, 5.0, 10, or 20 mg/kg i.p.) as well as the interaction between scopolamine and verapamil on memory consolidation in the step-through passive avoidance task, in Wistar rats. Our results showed that verapamil (1.0 and 2.5 mg/kg) administered immediately after the acquisition task significantly increased the latency of the passive avoidance response, on the 48 h retested trial, improving memory consolidation. On the other hand, verapamil in a dose of 5 mg/kg, that per se does not affect memory consolidation, significantly reversed the memory consolidation improvement induced by scopolamine (1 mg/kg, i.p., administered immediately after verapamil treatment) but did not change the passive avoidance response in rats treated by an ineffective dose of scopolamine (30 mg/kg). In conclusion, the present data suggest that (1) the post-training administration of verapamil, dose-dependently, improves the passive avoidance response; (2) verapamil, in ineffective dose, abolished the improvement of memory consolidation effect of scopolamine; and (3) exists interaction between cholinergic muscarinic receptors and calcium homeostasis-related mechanisms in the consolidation of emotional memory.
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Affiliation(s)
- Verónica Giménez De Béjar
- Department of Neurology, Hospital Quirónsalud MurciaMurcia, Spain.,Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain
| | - María Caballero Bleda
- Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain.,Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of MurciaMurcia, Spain
| | - Natalija Popović
- Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain.,Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of MurciaMurcia, Spain
| | - Miroljub Popović
- Instituto Murciano de Investigación Biosanitaria Virgen de la ArrixacaMurcia, Spain.,Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of MurciaMurcia, Spain
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Vargas-López V, Lamprea MR, Múnera A. Histone deacetylase inhibition abolishes stress-induced spatial memory impairment. Neurobiol Learn Mem 2016; 134 Pt B:328-38. [PMID: 27544851 DOI: 10.1016/j.nlm.2016.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/19/2016] [Accepted: 08/17/2016] [Indexed: 01/20/2023]
Abstract
Acute stress induced before spatial training impairs memory consolidation. Although non-epigenetic underpinning of such effect has been described, the epigenetic mechanisms involved have not yet been studied. Since spatial training and intense stress have opposite effects on histone acetylation balance, it is conceivable that disruption of such balance may underlie acute stress-induced spatial memory consolidation impairment and that inhibiting histone deacetylases prevents such effect. Trichostatin-A (TSA, a histone deacetylase inhibitor) was used to test its effectiveness in preventing stress' deleterious effect on memory. Male Wistar rats were trained in a spatial task in the Barnes maze; 1-h movement restraint was applied to half of them before training. Immediately after training, stressed and non-stressed animals were randomly assigned to receive either TSA (1mg/kg) or vehicle intraperitoneal injection. Twenty-four hours after training, long-term spatial memory was tested; plasma and brain tissue were collected immediately after the memory test to evaluate corticosterone levels and histone H3 acetylation in several brain areas. Stressed animals receiving vehicle displayed memory impairment, increased plasma corticosterone levels and markedly reduced histone H3 acetylation in prelimbic cortex and hippocampus. Such effects did not occur in stressed animals treated with TSA. The aforementioned results support the hypothesis that acute stress induced-memory impairment is related to histone deacetylation.
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Affiliation(s)
- Viviana Vargas-López
- Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia; Physiological Sciences Department, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Marisol R Lamprea
- Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia; Psychology Department, School of Human Sciences, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Alejandro Múnera
- Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia; Physiological Sciences Department, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia.
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Distribution and fate of DCX/PSA-NCAM expressing cells in the adult mammalian cortex: A local reservoir for adult cortical neuroplasticity? ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s11515-016-1403-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Nacher J, Bonfanti L. New neurons from old beliefs in the adult piriform cortex? A Commentary on: "Occurrence of new neurons in the piriform cortex". Front Neuroanat 2015; 9:62. [PMID: 26052272 PMCID: PMC4440910 DOI: 10.3389/fnana.2015.00062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/06/2015] [Indexed: 02/04/2023] Open
Affiliation(s)
- Juan Nacher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València Valencia, Spain ; CIBERSAM: Spanish National Network for Research in Mental Health Spain ; Fundación Investigación Hospital Clínico de Valencia, INCLIVA Valencia, Spain
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi Orbassano, Italy ; Department of Veterinary Sciences, University of Turin Torino, Italy
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9
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Time course of scopolamine effect on memory consolidation and forgetting in rats. Neurobiol Learn Mem 2015; 118:49-54. [DOI: 10.1016/j.nlm.2014.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 11/03/2014] [Accepted: 11/12/2014] [Indexed: 01/06/2023]
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10
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Orczyk JJ, Banks MK, Garraghty PE. The effects of valproic acid on appetitive and aversive instrumental learning in adult rats. Front Behav Neurosci 2014; 8:113. [PMID: 24744711 PMCID: PMC3978344 DOI: 10.3389/fnbeh.2014.00113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/17/2014] [Indexed: 11/13/2022] Open
Abstract
Antiepileptic medications are the frontline treatment for seizure conditions. However, these medications are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin and carbamazepine-treated rats. In the experiment reported here, the effects of valproic acid (VPA) have been studied using the same instrumental training tasks. VPA-treated rats displayed a severe deficit in acquiring a tone-signaled avoidance response. This deficit was attenuated in animals that had prior training in an appetitive context. Thus, this deficit is specific to learning in an aversive context, and does not result from difficulties in transferring associations from an appetitive to aversive context. Learning transfer deficits were previously observed in rats treated with phenytoin, and to a lesser extent, carbamazepine. On the other hand, rats treated with VPA fail to suppress inappropriate responsiveness across aversive training whether they had undergone prior appetitive training or not.
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Affiliation(s)
- John J Orczyk
- Department of Psychological and Brain Sciences, Indiana University Bloomington, IN, USA
| | - Melissa K Banks
- Department of Psychological and Brain Sciences, Indiana University Bloomington, IN, USA ; Program in Neuroscience, Indiana University Bloomington, IN, USA
| | - Preston E Garraghty
- Department of Psychological and Brain Sciences, Indiana University Bloomington, IN, USA ; Program in Neuroscience, Indiana University Bloomington, IN, USA
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Foley AG, Cassidy AW, Regan CM. Pentyl-4-yn-VPA, a histone deacetylase inhibitor, ameliorates deficits in social behavior and cognition in a rodent model of autism spectrum disorders. Eur J Pharmacol 2014; 727:80-6. [DOI: 10.1016/j.ejphar.2014.01.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 01/22/2014] [Accepted: 01/24/2014] [Indexed: 11/15/2022]
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Abstract
Histone acetylation is a prominent epigenetic modification of the central nervous system that is unequivocally associated with an increase in the rate of gene transcription. Because gene transcription, in turn, plays an important role in long-lasting forms of memory, histone acetylation generally favors long-term memory, whereas histone deacetylation impinges on it. Histone acetylation is also amenable to pharmacological interventions-predominantly by the use of histone deacetylase (HDAC) inhibitors-and has therefore spurred considerable interest as a putative target of cognitive enhancement. Because of the ubiquitous presence of histone acetylation, HDAC inhibitors have great potential not only to treat cognitive impairment resulting from neurodevelopmental and neurodegenerative disorders but also to serve as cognitive enhancers for the cognitively healthy. In this review, we summarize the state of the art of HDAC inhibitors as cognitive treatments or cognitive enhancers; describe a new model of their mode of action, epigenetic priming; and caution against their unsupervised usage, despite their overall great promise.
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Affiliation(s)
- Johannes Gräff
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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13
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Gräff J, Tsai LH. Histone acetylation: molecular mnemonics on the chromatin. Nat Rev Neurosci 2013; 14:97-111. [PMID: 23324667 DOI: 10.1038/nrn3427] [Citation(s) in RCA: 430] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Long-lasting memories require specific gene expression programmes that are, in part, orchestrated by epigenetic mechanisms. Of the epigenetic modifications identified in cognitive processes, histone acetylation has spurred considerable interest. Whereas increments in histone acetylation have consistently been shown to favour learning and memory, a lack thereof has been causally implicated in cognitive impairments in neurodevelopmental disorders, neurodegeneration and ageing. As histone acetylation and cognitive functions can be pharmacologically restored by histone deacetylase inhibitors, this epigenetic modification might constitute a molecular memory aid on the chromatin and, by extension, a new template for therapeutic interventions against cognitive frailty.
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Affiliation(s)
- Johannes Gräff
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Enantioselective apoptosis induction in histiocytic lymphoma cells and acute promyelocytic leukemia cells. Arch Toxicol 2012; 87:303-10. [PMID: 23010695 DOI: 10.1007/s00204-012-0930-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022]
Abstract
The aim of this study was to identify valproic acid (VPA) analogs with a broad spectrum of anti-cancer activities and an increased apoptosis-inducing potential compared with the parent VPA, which is enrolled as histone deacetylase (HDAC) inhibitor in a large number of clinical trials. We identified a chiral VPA derivative, (S)-2-pentyl-4-pentynoic acid, previously characterized as HDAC inhibitor that induced massive programmed cell death in a strongly enantioselective manner in U937 histiocytic lymphoma cells and NB4 acute promyelocytic leukemia cells. By performing fluorescence-activated cell sorting and Western blotting analyses, we established that enantiomer (S)-2-pentyl-4-pentynoic acid has higher apoptosis-inducing potential than VPA itself. The optic antipode (R)-2-pentyl-4-pentynoic acid and VPA caused under the same conditions only a weak growth inhibition without inducing cell differentiation and apoptosis. (S)-2-pentyl-4-pentynoic acid is more apoptogenic than VPA and displays enantioselective anti-cancer properties that warrant further research regarding the mechanistic basis of its activity and its potential use in cancer therapy.
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Bonfanti L, Nacher J. New scenarios for neuronal structural plasticity in non-neurogenic brain parenchyma: the case of cortical layer II immature neurons. Prog Neurobiol 2012; 98:1-15. [PMID: 22609484 DOI: 10.1016/j.pneurobio.2012.05.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 04/25/2012] [Accepted: 05/08/2012] [Indexed: 11/20/2022]
Abstract
The mammalian central nervous system, due to its interaction with the environment, must be endowed with plasticity. Conversely, the nervous tissue must be substantially static to ensure connectional invariability. Structural plasticity can be viewed as a compromise between these requirements. In adult mammals, brain structural plasticity is strongly reduced with respect to other animal groups in the phylogenetic tree. It persists under different forms, which mainly consist of remodeling of neuronal shape and connectivity, and, to a lesser extent, the production of new neurons. Adult neurogenesis is mainly restricted within two neurogenic niches, yet some gliogenic and neurogenic processes also occur in the so-called non-neurogenic tissue, starting from parenchymal progenitors. In this review we focus on a population of immature, non-newly generated neurons in layer II of the cerebral cortex, which were previously thought to be newly generated since they heavily express the polysialylated form of the neural cell adhesion molecule and doublecortin. These unusual neurons exhibit characteristics defining an additional type of structural plasticity, different from either synaptic plasticity or adult neurogenesis. Evidences concerning their morphology, antigenic features, ultrastructure, phenotype, origin, fate, and reaction to different kind of stimulations are gathered and analyzed. Their possible role is discussed in the context of an enriched complexity and heterogeneity of mammalian brain structural plasticity.
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Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano (TO), and Department of Veterinary Morphophysiology, University of Turin, Turin, Italy.
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16
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Kraev I, Henneberger C, Rossetti C, Conboy L, Kohler LB, Fantin M, Jennings A, Venero C, Popov V, Rusakov D, Stewart MG, Bock E, Berezin V, Sandi C. A peptide mimetic targeting trans-homophilic NCAM binding sites promotes spatial learning and neural plasticity in the hippocampus. PLoS One 2011; 6:e23433. [PMID: 21887252 PMCID: PMC3160849 DOI: 10.1371/journal.pone.0023433] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 07/17/2011] [Indexed: 01/10/2023] Open
Abstract
The key roles played by the neural cell adhesion molecule (NCAM) in plasticity and cognition underscore this membrane protein as a relevant target to develop cognitive-enhancing drugs. However, NCAM is a structurally and functionally complex molecule with multiple domains engaged in a variety of actions, which raise the question as to which NCAM fragment should be targeted. Synthetic NCAM mimetic peptides that mimic NCAM sequences relevant to specific interactions allow identification of the most promising targets within NCAM. Recently, a decapeptide ligand of NCAM—plannexin, which mimics a homophilic trans-binding site in Ig2 and binds to Ig3—was developed as a tool for studying NCAM's trans-interactions. In this study, we investigated plannexin's ability to affect neural plasticity and memory formation. We found that plannexin facilitates neurite outgrowth in primary hippocampal neuronal cultures and improves spatial learning in rats, both under basal conditions and under conditions involving a deficit in a key plasticity-promoting posttranslational modification of NCAM, its polysialylation. We also found that plannexin enhances excitatory synaptic transmission in hippocampal area CA1, where it also increases the number of mushroom spines and the synaptic expression of the AMPAR subunits GluA1 and GluA2. Altogether, these findings provide compelling evidence that plannexin is an important facilitator of synaptic functional, structural and molecular plasticity in the hippocampal CA1 region, highlighting the fragment in NCAM's Ig3 module where plannexin binds as a novel target for the development of cognition-enhancing drugs.
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Affiliation(s)
- Igor Kraev
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
| | - Christian Henneberger
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Clara Rossetti
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Lisa Conboy
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Lene B. Kohler
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Martina Fantin
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
| | - Alistair Jennings
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Cesar Venero
- Department of Psychobiology, UNED, Ciudad Universitaria, Madrid, Spain
| | - Victor Popov
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
| | - Dmitri Rusakov
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London (UCL), London, United Kingdom
| | - Michael G. Stewart
- Department of Life Sciences, The Open University, Milton Keynes, United Kingdom
- * E-mail: (CS); (MGS)
| | - Elisabeth Bock
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Vladimir Berezin
- Protein Laboratory, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, EPFL, Lausanne, Switzerland
- * E-mail: (CS); (MGS)
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17
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Olfactory bulbectomy, but not odor conditioned aversion, induces the differentiation of immature neurons in the adult rat piriform cortex. Neuroscience 2011; 181:18-27. [DOI: 10.1016/j.neuroscience.2011.03.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/28/2011] [Accepted: 03/01/2011] [Indexed: 01/11/2023]
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18
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Varea E, Belles M, Vidueira S, Blasco-Ibáñez JM, Crespo C, Pastor AM, Nacher J. PSA-NCAM is Expressed in Immature, but not Recently Generated, Neurons in the Adult Cat Cerebral Cortex Layer II. Front Neurosci 2011; 5:17. [PMID: 21415912 PMCID: PMC3042688 DOI: 10.3389/fnins.2011.00017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Accepted: 01/31/2011] [Indexed: 12/17/2022] Open
Abstract
Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) and their phenotype using markers of mature neurons and different interneuronal populations. Additionally, we have explored the origin of these cells administering 5′bromodeoxyuridine (5′BrdU) during adulthood. Immature neurons were widely dispersed in the cerebral cortex layers II and upper III, being specially abundant in the piriform and entorhinal cortices, in the ventral portions of the frontal and temporoparietal lobes, but relatively scarce in dorsal regions, such as the primary visual areas. Only a small fraction of PSA-NCAM expressing cells in layer II expressed the mature neuronal marker NeuN and virtually none of them expressed calcium binding proteins or neuropeptides. By contrast, most, if not all of these cells expressed the transcription factor Tbr-1, specifically expressed by pallium-derived principal neurons, but not CAMKII, a marker of mature excitatory neurons. Absence of PSA-NCAM/5′BrdU colocalization suggests that, as in rats, these cells were not generated during adulthood. Together, these results indicate that immature neurons in the adult cat cerebral cortex layer II are not recently generated and that they may differentiate into principal neurons.
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Affiliation(s)
- Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Department of Cell Biology, Universitat de València València, Spain
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19
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Fagundo AB, Cuyàs E, Verdejo-Garcia A, Khymenets O, Langohr K, Martín-Santos R, Farré M, de la Torre R. The influence of 5-HTT and COMT genotypes on verbal fluency in ecstasy users. J Psychopharmacol 2010; 24:1381-93. [PMID: 20080926 DOI: 10.1177/0269881109354926] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Deficits in verbal fluency associated with ecstasy use have been well established; however, the mechanisms underlying this impairment have yet to be elucidated. In this study we investigated for the first time whether there was a disproportionate impairment in two cognitive subcomponents of verbal fluency: clustering (ability to generate words within the same subcategory) and switching (ability to change the subcategory). We also investigated a possible association between ecstasy use and verbal fluency in subjects genotyped for 5-HTT (5-HTTLPR and 5-HTTVNTR) and COMT (val(108/158)met, rs165599 and rs2097603) polymorphisms, in order to find a potential implication of genetic factors. Ecstasy polydrug users (n = 30) and non-ecstasy users (n = 41) were evaluated in both semantic and phonemic fluency. Results showed that ecstasy users had poorer semantic (but not phonemic) fluency performance than controls. Detailed analysis of clustering and switching performance revealed that this impairment was associated with poorer clustering mechanisms. Clustering was also modulated by the COMT rs165599 polymorphism independently of the group. A specific effect of the 5-HTTLPR polymorphism on switching performance was also found, with ss carriers performing significantly worse than ls and ll carriers, suggesting a serotonin modulation of frontal-executive flexibility. Based on the impaired clustering and switching strategies observed in ecstasy users, it might be proposed that both semantic knowledge and retrieval are impaired in this population. The verbal fluency deficit in ecstasy users may be attributable to a disruption of frontal-striatal circuits directly related with the serotonin function as well as a depletion of lexical-semantic stores mediated by temporal structures.
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Affiliation(s)
- Ana B Fagundo
- Human Pharmacology and Clinical Neurosciences Research Group-Neuropsychopharmacology Program, Institut Municipal d'Investigació Mèdica (IMIM), Barcelona, Spain
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20
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Ragancokova D, Song Y, Nau H, Dengler R, Krampfl K, Petri S. Modulation of synaptic transmission and analysis of neuroprotective effects of valproic Acid and derivates in rat embryonic motoneurons. Cell Mol Neurobiol 2010; 30:891-900. [PMID: 20422280 DOI: 10.1007/s10571-010-9518-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/30/2010] [Indexed: 01/06/2023]
Abstract
Amyotrophic lateral sclerosis is a devastating motoneuron disorder for which no effective treatment exists. There is some evidence for neuroprotective effects of valproic acid (VPA). The beneficial effects, however, are limited due to the adverse effects of VPA. To overcome this problem, a number of VPA derivates with fewer side effects have been synthesized. In the present study, we investigated the viability of highly purified embryonic motoneurons cultured on glial feeder layers, composed of either astrocytes or Schwann cells, or in monoculture, in presence of VPA and its three derivates 3-propyl-heptanoic acid (3-PHA), PE-4-yn enantiomers (R- and S-PE-4-yn). An excitotoxic stimulus, kainate (KA), was added at day in vitro 9 (DIV9) and the neuroprotective effect of either simultaneous incubation (DIV9) or pre-incubation (DIV1) of VPA and its derivates was tested. The survival of motoneurons under simultaneous application of KA and VPA derivates was not remarkably increased. Pre-incubation with VPA and even more with the derivates before the addition of KA, however, significantly reduced their vulnerability against the KA-induced neurotoxic effect. Our data suggest that the neuroprotective capacities of VPA and its three derivates tested here drastically increase when they are added several days before KA. Most prominent neuroprotective effects were seen for the PE-4-yn enantiomers. Patch-clamp experiments revealed an antiexcitotoxic effect of the S-PE-4-yn enantiomer that reduces the frequency of postsynaptic currents and enhances the inhibitory postsynaptic transmission dependent on the co-culture condition.
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Affiliation(s)
- D Ragancokova
- Department of Neurology and Clinical Neurophysiology, Hannover Medical School, OE 7210, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany.
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21
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Abstract
The anticonvulsant properties of VPA (valproic acid), a branched short-chain fatty acid, were serendipitously discovered in 1963. Since then, therapeutic roles of VPA have increased to include bipolar disorder and migraine prophylaxis, and have more recently been proposed in cancer, Alzheimer's disease and HIV treatment. These numerous therapeutic roles elevate VPA to near 'panacea' level. Surprisingly, the mechanisms of action of VPA in the treatment of many of these disorders remain unclear, although it has been shown to alter a wide variety of signalling pathways and a small number of direct targets. To analyse the mechanism of action of VPA, a number of studies have defined the structural characteristics of VPA-related compounds giving rise to distinct therapeutic and cellular effects, including adverse effects such as teratogenicity and hepatotoxicity. These studies raise the possibility of identifying target-specific novel compounds, providing better therapeutic action or reduced side effects. This short review will describe potential therapeutic pathways targeted by VPA, and highlight studies showing structural constraints necessary for these effects.
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22
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Saavedra A, Baltazar G, Duarte EP. Driving GDNF expression: the green and the red traffic lights. Prog Neurobiol 2008; 86:186-215. [PMID: 18824211 DOI: 10.1016/j.pneurobio.2008.09.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 06/18/2008] [Accepted: 09/03/2008] [Indexed: 01/28/2023]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is widely recognized as a potent survival factor for dopaminergic neurons of the nigrostriatal pathway that degenerate in Parkinson's disease (PD). In animal models of PD, GDNF delivery to the striatum or the substantia nigra protects dopaminergic neurons against subsequent toxin-induced injury and rescues previously damaged neurons, promoting recovery of the motor function. Thus, GDNF was proposed as a potential therapy to PD aimed at slowing down, halting or reversing neurodegeneration, an issue addressed in previous reviews. However, the use of GDNF as a therapeutic agent for PD is hampered by the difficulty in delivering it to the brain. Another potential strategy is to stimulate the endogenous expression of GDNF, but in order to do that we need to understand how GDNF expression is regulated. The aim of this review is to do a comprehensive analysis of the state of the art on the control of endogenous GDNF expression in the nervous system, focusing mainly on the nigrostriatal pathway. We address the control of GDNF expression during development, in the adult brain and after injury, and how damaged neurons signal glial cells to up-regulate GDNF. Pharmacological agents or natural molecules that increase GDNF expression and show neuroprotective activity in animal models of PD are reviewed. We also provide an integrated overview of the signalling pathways linking receptors for these molecules to the induction of GDNF gene, which might also become targets for neuroprotective therapies in PD.
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Affiliation(s)
- Ana Saavedra
- Department of Cell Biology, Immunology and Neurosciences, Faculty of Medicine, University of Barcelona, Carrer Casanova 143, 08036 Barcelona, Spain.
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23
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Gravemann U, Volland J, Nau H. Hydroxamic acid and fluorinated derivatives of valproic acid: Anticonvulsant activity, neurotoxicity and teratogenicity. Neurotoxicol Teratol 2008; 30:390-4. [DOI: 10.1016/j.ntt.2008.03.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 02/26/2008] [Accepted: 03/10/2008] [Indexed: 02/05/2023]
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24
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Gómez-Climent MA, Castillo-Gómez E, Varea E, Guirado R, Blasco-Ibáñez JM, Crespo C, Martínez-Guijarro FJ, Nácher J. A population of prenatally generated cells in the rat paleocortex maintains an immature neuronal phenotype into adulthood. ACTA ACUST UNITED AC 2008; 18:2229-40. [PMID: 18245040 DOI: 10.1093/cercor/bhm255] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
New neurons in the adult brain transiently express molecules related to neuronal development, such as the polysialylated form of neural cell adhesion molecule, or doublecortin (DCX). These molecules are also expressed by a cell population in the rat paleocortex layer II, whose origin, phenotype, and function are not clearly understood. We have classified most of these cells as a new cell type termed tangled cell. Some cells with the morphology of semilunar-pyramidal transitional neurons were also found among this population, as well as some scarce cells resembling semilunar, pyramidal. and fusiform neurons. We have found that none of these cells in layer II express markers of glial cells, mature, inhibitory, or principal neurons. They appear to be in a prolonged immature state, confirmed by the coexpression of DCX, TOAD/Ulip/CRMP-4, A3 subunit of the cyclic nucleotide-gated channel, or phosphorylated cyclic adenosine monophosphate response element-binding protein. Moreover, most of them lack synaptic contacts, are covered by astroglial lamellae, and fail to express cellular activity markers, such as c-Fos or Arc, and N-methyl-d-aspartate or glucocorticoid receptors. We have found that none of these cells appear to be generated during adulthood or early youth and that most of them have been generated during embryonic development, mainly in E15.5.
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Affiliation(s)
- María Angeles Gómez-Climent
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Dpt., Universitat de València, Spain
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25
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Bredy TW, Barad M. The histone deacetylase inhibitor valproic acid enhances acquisition, extinction, and reconsolidation of conditioned fear. Learn Mem 2008; 15:39-45. [PMID: 18174372 DOI: 10.1101/lm.801108] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Histone modifications contribute to the epigenetic regulation of gene expression, a process now recognized to be important for the consolidation of long-term memory. Valproic acid (VPA), used for many years as an anticonvulsant and a mood stabilizer, has effects on learning and memory and enhances the extinction of conditioned fear through its function as a histone deacetylase inhibitor (HDAC). Here we report that VPA enhances long-term memory for both acquisition and extinction of cued-fear. Interestingly, VPA enhances extinction, but also enhances renewal of the original conditioned fear when tested in a within-subjects design. This effect appears to be related to a reconsolidation-like process since a single CS reminder in the presence of VPA can enhance long-term memory for the original fear in the context in which fear conditioning takes place. We also show that by modifying the intertrial interval during extinction training, VPA can strengthen reconsolidation of the original fear memory or enhance long-term memory for extinction such that it becomes independent of context. These findings have important implications for the use of HDAC inhibitors as adjuncts to behavior therapy in the treatment of phobia and related anxiety disorders.
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Affiliation(s)
- Timothy W Bredy
- Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California 90095, USA
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26
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Bredy TW, Wu H, Crego C, Zellhoefer J, Sun YE, Barad M. Histone modifications around individual BDNF gene promoters in prefrontal cortex are associated with extinction of conditioned fear. Learn Mem 2007; 14:268-76. [PMID: 17522015 PMCID: PMC2216532 DOI: 10.1101/lm.500907] [Citation(s) in RCA: 415] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Extinction of conditioned fear is an important model both of inhibitory learning and of behavior therapy for human anxiety disorders. Like other forms of learning, extinction learning is long-lasting and depends on regulated gene expression. Epigenetic mechanisms make an important contribution to persistent changes in gene expression; therefore, in these studies, we have investigated whether epigenetic regulation of gene expression contributes to fear extinction. Since brain-derived neurotrophic factor (BDNF) is crucial for synaptic plasticity and for the maintenance of long-term memory, we examined histone modifications around two BDNF gene promoters after extinction of cued fear, as potential targets of learning-induced epigenetic regulation of gene expression. Valproic acid (VPA), used for some time as an anticonvulsant and a mood stabilizer, modulates the expression of BDNF, and is a histone deacetylase (HDAC) inhibitor. Here, we report that extinction of conditioned fear is accompanied by a significant increase in histone H4 acetylation around the BDNF P4 gene promoter and increases in BDNF exon I and IV mRNA expression in prefrontal cortex, that VPA enhances long-term memory for extinction because of its HDAC inhibitor effects, and that VPA potentiates the effect of weak extinction training on histone H4 acetylation around both the BDNF P1 and P4 gene promoters and on BDNF exon IV mRNA expression. These results suggest a relationship between histone H4 modification, epigenetic regulation of BDNF gene expression, and long-term memory for extinction of conditioned fear. In addition, they suggest that HDAC inhibitors may become a useful pharmacological adjunct to psychotherapy for human anxiety disorders.
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Affiliation(s)
- Timothy W. Bredy
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Hao Wu
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Cortney Crego
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Jessica Zellhoefer
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Yi E. Sun
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Mark Barad
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
- West Los Angeles VA Medical Center, Los Angeles, California 90073, USA
- Corresponding author.E-mail ; fax (310) 825-9870
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27
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Foster TC, Kumar A. Susceptibility to induction of long-term depression is associated with impaired memory in aged Fischer 344 rats. Neurobiol Learn Mem 2007; 87:522-35. [PMID: 17276704 PMCID: PMC1896085 DOI: 10.1016/j.nlm.2006.12.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 12/15/2006] [Accepted: 12/18/2006] [Indexed: 02/03/2023]
Abstract
The current study employed aged and young male Fischer 344 rats to examine the relationship between long-term depression (LTD), age, and memory. Memory performance was measured on two tasks that are sensitive to hippocampal function; inhibitory avoidance and spatial discrimination on the Morris water maze. The slope of the extracellular excitatory postsynaptic field potential was recorded from CA3-CA1 synapses in hippocampal slices. Low frequency stimulation (LFS) induced a modest LTD only in aged animals under standard recording conditions. The decrease in synaptic transmission examined only in aged animals correlated with memory scores on the spatial task and LTD was not observed in aged animals with the highest memory scores. LTD induction was facilitated by increasing the Ca(2+)/Mg(2+) ratio of the recording medium or employing a paired-pulse stimulation paradigm. Age differences disappeared when LFS was delivered under conditions of elevated Ca(2+)/Mg(2+) in the recording medium. Using multiple induction episodes under conditions which facilitate LTD-induction, no age-related difference was observed in the maximum level of LTD. The results indicate that the increased susceptibility to LTD induction is associated with impaired memory and results from a shift in the induction process. The possible relationship between LTD and memory function is discussed.
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Affiliation(s)
- Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
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28
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Gotfryd K, Owczarek S, Hoffmann K, Klementiev B, Nau H, Berezin V, Bock E, Walmod PS. Multiple effects of pentyl-4-yn-VPA enantiomers: from toxicity to short-term memory enhancement. Neuropharmacology 2006; 52:764-78. [PMID: 17095022 DOI: 10.1016/j.neuropharm.2006.09.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 09/25/2006] [Accepted: 09/25/2006] [Indexed: 10/23/2022]
Abstract
2-n-Pentyl-4-pentynoic acid (PE-4-yn-VPA) is a derivative of the antiepileptic and mood-stabilizing drug valproic acid (VPA). PE-4-yn-VPA exists as R- and S-enantiomers, the latter being more teratogenic. PE-4-yn-VPA also possesses antiepileptic, antiproliferative, and cell-differentiating properties. Moreover, the less teratogenic enantiomer, R-PE-4-yn-VPA, was recently shown to improve learning and memory. We here present a detailed investigation of the enantioselective properties of PE-4-yn-VPA using a range of in vitro and in vivo assays including measurements of cellular growth and migration, neuronal differentiation and survival, intracellular signal transduction, synaptic plasticity and maturation, and short-term memory as determined by the social recognition test. The results show that the enantiomers of PE-4-yn-VPA largely had similar effects in vitro. However, in all in vitro experiments the more teratogenic enantiomer, S-PE-4-yn-VPA, exhibited a stronger potency than R-PE-4-yn-VPA, and only S-PE-4-yn-VPA had a detrimental effect on cell survival. Interestingly, both the R- and S-enantiomer improved learning and memory. In contrast, the beneficial effect of S-PE-4-yn-VPA on memory was lost by time, whereas the effect of R-PE-4-yn-VPA administration was longer lasting, suggesting that the beneficial effect of the S-enantiomer on memory formation may be counteracted by its detrimental effect on neuronal cell survival.
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Affiliation(s)
- Kamil Gotfryd
- Protein Laboratory, Institute of Molecular Pathology, Panum Institute, University of Copenhagen, Blegdamsvej 3C Bld. 6.2, DK-2200 Copenhagen N, Denmark
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29
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Foley AG, Murphy KJ, Regan CM. Complex-environment rearing prevents prenatal hypoxia-induced deficits in hippocampal cellular mechanisms necessary for memory consolidation in the adult Wistar rat. J Neurosci Res 2006; 82:245-54. [PMID: 16175578 DOI: 10.1002/jnr.20641] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hypoxic episodes in utero can result in enduring and debilitating neurological sequelae that include nonprogressive motor disorders and/or significant learning deficits. The extent of long-term disruption of synaptic function following prenatal hypoxia and its subsequent effect on learning ability, however, remain to be established. Polysialylation of the neural cell adhesion molecule, a cellular event integral to the consolidation of diverse learning paradigms, was used to correlate cellular end points with learning deficits as a consequence of prenatal hypoxia. Pregnant Wistar dams exposed to hypobaric hypoxia during gestational days 10-20 had significantly reduced litter sizes, but the lack of effect on subsequent pup weight gain suggested no gross developmental deficit. By contrast, adult animals with prior in utero hypoxia exhibited significant learning difficulties in both acquisition of a water maze spatial learning task and recall of a passive avoidance paradigm. Learning deficits correlated with a significant reduction in the frequency of polysialylated neurons in the dentate infragranular zone and a blunting of their transient activation 12 hr following task acquisition. Rearing animals with prior prenatal hypoxia in a complex environment, however, eliminated the task acquisition and recall deficits and restored dentate polysialylated cell frequency and their transient posttraining increase.
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Affiliation(s)
- Andrew G Foley
- Department of Pharmacology, The Conway Institute, University College Dublin, Belfield, Dublin, Ireland
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30
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Stewart MG, Davies HA, Sandi C, Kraev IV, Rogachevsky VV, Peddie CJ, Rodriguez JJ, Cordero MI, Donohue HS, Gabbott PLA, Popov VI. Stress suppresses and learning induces plasticity in CA3 of rat hippocampus: a three-dimensional ultrastructural study of thorny excrescences and their postsynaptic densities. Neuroscience 2005; 131:43-54. [PMID: 15680690 DOI: 10.1016/j.neuroscience.2004.10.031] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2004] [Indexed: 11/18/2022]
Abstract
Chronic stress and spatial training have been proposed to affect hippocampal structure and function in opposite ways. Previous morphological studies that addressed structural changes after chronic restraint stress and spatial training were based on two-dimensional morphometry which does not allow a complete morphometric characterisation of synaptic features. Here, for the first time in such studies, we examined these issues by using three-dimensional (3-D) reconstructions of electron microscope images taken from thorny excrescences of hippocampal CA3 pyramidal cells. Ultrastructural alterations in postsynaptic densities (PSDs) of thorny excrescences receiving input from mossy fibre boutons were also determined, as were changes in numbers of multivesicular bodies (endosome-like structures) within thorny excrescences and dendrites. Quantitative 3-D data demonstrated retraction of thorny excrescences after chronic restraint stress which was reversed after water maze training, whilst water maze training alone increased thorny excrescence volume and number of thorns per thorny excrescence. PSD surface area was unaffected by restraint stress but water maze training increased both number and area of PSDs per thorny excrescence. In restrained rats that were water maze trained PSD volume and surface area increased significantly. The proportion of perforated PSDs almost doubled after water maze training and restraint stress. Numbers of endosome-like structures in thorny excrescences decreased after restraint stress and increased after water maze training. These findings demonstrate that circuits involving contacts between mossy fibre terminals and CA3 pyramidal cells at stratum lucidum level are affected conversely by water maze training and chronic stress, confirming the remarkable plasticity of CA3 dendrites. They provide a clear illustration of the structural modifications that occur after life experiences noted for their different impact on hippocampal function.
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Affiliation(s)
- M G Stewart
- Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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Gallagher HC, Bacon CL, Odumeru OA, Gallagher KF, Fitzpatrick T, Regan CM. Valproate activates phosphodiesterase-mediated cAMP degradation: relevance to C6 glioma G1 phase progression. Neurotoxicol Teratol 2004; 26:73-81. [PMID: 15001216 DOI: 10.1016/j.ntt.2003.07.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2003] [Accepted: 07/18/2003] [Indexed: 10/27/2022]
Abstract
Forskolin, a diterpene activator of adenylate cyclase, stimulates the production of cyclic adenosine monophosphate (cAMP) in a wide variety of cell types. In C6 glioma, used in this study, the anticonvulsant agent valproic acid (VPA) inhibited forskolin-stimulated cAMP accumulation in intact cells in a concentration-dependent manner. Kinetic studies indicated this valproate effect not to be mediated by direct inhibition of adenylate cyclase activity. The valproate-induced inhibition of cAMP accumulation was partially reversed by the phosphodiesterase (PDE) inhibitor isobutylmethyl xanthine (IBMX). Degradation of cAMP over time was more rapid in valproate-treated cells than in controls, and this effect was also reversed by IBMX. In synchronised C6 glioma, phosphodiesterase type IV (PDE4A1) expression was selectively upregulated during the G1 phase, in tandem with temporal biphasic peaks of cAMP. However, the expression of PDE4 isoforms was not affected by a 48-h exposure to valproate. These findings suggest inhibition of forskolin-stimulated cAMP levels in C6 glioma by valproate to be mediated by increased activation of PDE in the G1 phase. Since the degree of cell cycle arrest induced by valproate is intimately associated with its teratogenic potency, it appears that PDE-mediated inhibition of cAMP may contribute to the molecular mechanisms of valproate-induced teratogenicity.
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Affiliation(s)
- Helen C Gallagher
- Department of Pharmacology, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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Foley AG, Gallagher HC, Murphy KJ, Regan CM. Pentyl-4-yn-valproic acid reverses age-associated memory impairment in the Wistar rat. Neurobiol Aging 2004; 25:539-46. [PMID: 15013575 DOI: 10.1016/j.neurobiolaging.2003.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2002] [Revised: 07/14/2003] [Accepted: 07/23/2003] [Indexed: 10/26/2022]
Abstract
Pentyl-4-yn-valproic acid (VPA), a cognition-enhancing agent whose mode of action has been attributed to cell adhesion molecule-mediated neuritogenesis, has been shown to enhance hippocampus-dependent spatial learning. Here, we investigated its potential to reverse age-related memory impairment that relates mainly to declarative memory. Aged spatial learning deficits in the water maze paradigm were demonstrated by swim angle analysis, the angle between axes of start-to-platform and start-to-animal position, and latency to reach a submerged platform. Chronic pentyl-4-yn-VPA administration mediated a significant improvement in both search strategy and latency to find the submerged platform in aged animals. Pentyl-4-yn-VPA also facilitated task recall in aged animals as evidenced by increased time in the target quadrant during a probe trial 3 days following the final training session. The action of pentyl-4-yn-VPA on platform latency, search strategy and task recall suggests that this agent may have great benefit in the treatment of age-dependent cognitive decline.
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Affiliation(s)
- Andrew G Foley
- Department of Pharmacology, The Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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O'Loinsigh ED, Gherardini LM, Gallagher HC, Foley AG, Murphy KJ, Regan CM. Differential enantioselective effects of pentyl-4-yn-valproate on spatial learning in the rat, and neurite outgrowth and cyclin D3 expression in vitro. J Neurochem 2003; 88:370-9. [PMID: 14690525 DOI: 10.1111/j.1471-4159.2004.02158.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previously, we demonstrated the racemic form of the valproate (VPA) analogue, 2-n-pentyl-4-pentynoic acid ([+/-]pentyl-4-yn-VPA), to be neuritogenic in vitro and to enhance cognition in vivo. To determine the enantioselectivity of these effects, the racemate and purified enantiomers of [+/-]pentyl-4-yn-VPA (84 mg/kg, i.p.) were administered to rodents 20 min prior to multi-session water maze training. The racemate and R-enantiomer significantly reduced escape latencies during water maze learning and enhanced its recall in a probe trial 3 days later. In contrast, S-pentyl-4-yn-VPA did not influence these behavioural parameters. The enantiomer-specific effects of [+/-]pentyl-4-yn-VPA were further discriminated in vitro using neuro 2A neuroblastoma and C6 glioma cell lines. In neuro 2A, the S-enantiomer induced profound neurite outgrowth at concentrations up to 0.5 mm, with the R-enantiomer and racemate being less neuritogenic. Immunoblot analysis of cyclin D3 expression in C6 glioma indicated the racemate and S-pentyl-4-yn-VPA to induce dose-dependent up-regulation of this protein, similar to that associated with G1-phase cell cycle arrest mediated by VPA, whereas R-pentyl-4-yn-VPA was without effect. These results indicate that the cognition-enhancing effects of pentyl-4-yn-VPA are due to the actions of the R-enantiomer, and that cyclin D3 up-regulation and associated anti-proliferative and pro-differentiative actions are predominantly associated with the S-enantiomer.
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Affiliation(s)
- Eamon D O'Loinsigh
- Department of Pharmacology, Conway Institute, University College, Dublin, Ireland
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Affiliation(s)
- F J E Vajda
- Australian Centre for Clinical Neuropharmacology - Raoul Wallenberg Centre, St Vincent's Hospital and University of Melbourne, Fitzroy, VIC 3065, Australia.
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Abstract
Valproic acid (VPA, 2-propylpentanoic acid) is an established drug in the long-term therapy of epilepsy. During the past years, it has become evident that VPA is also associated with anti-cancer activity. VPA not only suppresses tumor growth and metastasis, but also induces tumor differentiation in vitro and in vivo. Several modes of action might be relevant for the biological activity of VPA: (1) VPA increases the DNA binding of activating protein-1 (AP-1) transcription factor, and the expression of genes regulated by the extracellular-regulated kinase (ERK)-AP-1 pathway; (2) VPA downregulates protein kinase C (PKC) activity; (3) VPA inhibits glycogen synthase kinase-3beta (GSK-3beta), a negative regulator of the Wnt signaling pathway; (4) VPA activates the peroxisome proliferator-activated receptors PPARgamma and delta; (5) VPA blocks HDAC (histone deacetylase), causing hyperacetylation. The findings elucidate an important role of VPA for cancer therapy. VPA might also be useful as low toxicity agent given over long time periods for chemoprevention and/or for control of residual minimal disease.
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Affiliation(s)
- Roman A Blaheta
- Zentrum der Hygiene, Institut für Medizinische Virologie, Interdisziplinäres Labor für Tumor- und Virus for schung, Klinikum der J. W. Goethe-Universität, Frankfurt am Main, Germany
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