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Martins-Ferreira R, Leal B, Chaves J, Ciudad L, Samões R, Martins da Silva A, Pinho Costa P, Ballestar E. Circulating cell-free DNA methylation mirrors alterations in cerebral patterns in epilepsy. Clin Epigenetics 2022; 14:188. [PMID: 36575526 PMCID: PMC9795776 DOI: 10.1186/s13148-022-01416-2] [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: 08/08/2022] [Accepted: 12/19/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND DNA methylation profiling of circulating cell-free DNA (cfDNA) has rapidly become a promising strategy for biomarker identification and development. The cell-type-specific nature of DNA methylation patterns and the direct relationship between cfDNA and apoptosis can potentially be used non-invasively to predict local alterations. In addition, direct detection of altered DNA methylation patterns performs well as a biomarker. In a previous study, we demonstrated marked DNA methylation alterations in brain tissue from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). RESULTS We performed DNA methylation profiling in cfDNA isolated from the serum of MTLE patients and healthy controls using BeadChip arrays followed by systematic bioinformatic analysis including deconvolution analysis and integration with DNase accessibility data sets. Differential cfDNA methylation analysis showed an overrepresentation of gene ontology terms and transcription factors related to central nervous system function and regulation. Deconvolution analysis of the DNA methylation data sets ruled out the possibility that the observed differences were due to changes in the proportional contribution of cortical neurons in cfDNA. Moreover, we found no overrepresentation of neuron- or glia-specific patterns in the described cfDNA methylation patterns. However, the MTLE-HS cfDNA methylation patterns featured a significant overrepresentation of the epileptic DNA methylation alterations previously observed in the hippocampus. CONCLUSIONS Our results support the use of cfDNA methylation profiling as a rational approach to seeking non-invasive and reproducible epilepsy biomarkers.
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Affiliation(s)
- Ricardo Martins-Ferreira
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916 Badalona, Barcelona Spain ,grid.5808.50000 0001 1503 7226Immunogenetics Laboratory, Molecular Pathology and Immunology Instituto de Ciências Biomédicas Abel Salazar – Universidade do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,Autoimmunity and Neuroscience Group, Unit for Multidisciplinary Research in Biomedicine (UMIB), ICBAS-UPorto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,grid.5808.50000 0001 1503 7226Laboratório Para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), Porto, Portugal
| | - Bárbara Leal
- grid.5808.50000 0001 1503 7226Immunogenetics Laboratory, Molecular Pathology and Immunology Instituto de Ciências Biomédicas Abel Salazar – Universidade do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,Autoimmunity and Neuroscience Group, Unit for Multidisciplinary Research in Biomedicine (UMIB), ICBAS-UPorto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,grid.5808.50000 0001 1503 7226Laboratório Para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), Porto, Portugal
| | - João Chaves
- Autoimmunity and Neuroscience Group, Unit for Multidisciplinary Research in Biomedicine (UMIB), ICBAS-UPorto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,grid.5808.50000 0001 1503 7226Laboratório Para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), Porto, Portugal ,grid.413438.90000 0004 0574 5247Neurology Service, Hospital de Santo António - Centro Hospitalar Universitário do Porto (HSA-CHUP), Porto, Portugal
| | - Laura Ciudad
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916 Badalona, Barcelona Spain
| | - Raquel Samões
- grid.413438.90000 0004 0574 5247Neurology Service, Hospital de Santo António - Centro Hospitalar Universitário do Porto (HSA-CHUP), Porto, Portugal
| | - António Martins da Silva
- Autoimmunity and Neuroscience Group, Unit for Multidisciplinary Research in Biomedicine (UMIB), ICBAS-UPorto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,grid.5808.50000 0001 1503 7226Laboratório Para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), Porto, Portugal ,Neurophysiology Service, HSA-CHUP, Porto, Portugal
| | - Paulo Pinho Costa
- grid.5808.50000 0001 1503 7226Immunogenetics Laboratory, Molecular Pathology and Immunology Instituto de Ciências Biomédicas Abel Salazar – Universidade do Porto (ICBAS-UPorto), Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,Autoimmunity and Neuroscience Group, Unit for Multidisciplinary Research in Biomedicine (UMIB), ICBAS-UPorto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal ,grid.5808.50000 0001 1503 7226Laboratório Para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), Porto, Portugal ,grid.422270.10000 0001 2287 695XDepartment of Human Genetics, Instituto Nacional de Saúde Dr. Ricardo Jorge, Porto, Portugal
| | - Esteban Ballestar
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916 Badalona, Barcelona Spain ,grid.22069.3f0000 0004 0369 6365Epigenetics in Inflammatory and Metabolic Diseases Laboratory, Health Science Center (HSC), East China Normal University (ECNU), Shanghai, 200241 China
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Szkop KJ, Cooke PIC, Humphries JA, Kalna V, Moss DS, Schuster EF, Nobeli I. Dysregulation of Alternative Poly-adenylation as a Potential Player in Autism Spectrum Disorder. Front Mol Neurosci 2017; 10:279. [PMID: 28955198 PMCID: PMC5601403 DOI: 10.3389/fnmol.2017.00279] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/17/2017] [Indexed: 11/30/2022] Open
Abstract
We present here the hypothesis that alternative poly-adenylation (APA) is dysregulated in the brains of individuals affected by Autism Spectrum Disorder (ASD), due to disruptions in the calcium signaling networks. APA, the process of selecting different poly-adenylation sites on the same gene, yielding transcripts with different-length 3′ untranslated regions (UTRs), has been documented in different tissues, stages of development and pathologic conditions. Differential use of poly-adenylation sites has been shown to regulate the function, stability, localization and translation efficiency of target RNAs. However, the role of APA remains rather unexplored in neurodevelopmental conditions. In the human brain, where transcripts have the longest 3′ UTRs and are thus likely to be under more complex post-transcriptional regulation, erratic APA could be particularly detrimental. In the context of ASD, a condition that affects individuals in markedly different ways and whose symptoms exhibit a spectrum of severity, APA dysregulation could be amplified or dampened depending on the individual and the extent of the effect on specific genes would likely vary with genetic and environmental factors. If this hypothesis is correct, dysregulated APA events might be responsible for certain aspects of the phenotypes associated with ASD. Evidence supporting our hypothesis is derived from standard RNA-seq transcriptomic data but we suggest that future experiments should focus on techniques that probe the actual poly-adenylation site (3′ sequencing). To address issues arising from the use of post-mortem tissue and low numbers of heterogeneous samples affected by confounding factors (such as the age, gender and health of the individuals), carefully controlled in vitro systems will be required to model the effect of calcium signaling dysregulation in the ASD brain.
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Affiliation(s)
- Krzysztof J Szkop
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Peter I C Cooke
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Joanne A Humphries
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Viktoria Kalna
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - David S Moss
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | | | - Irene Nobeli
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
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Differences in the Biological Functions of BDNF and proBDNF in the Central Nervous System. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s11055-017-0391-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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4
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Mallei A, Baj G, Ieraci A, Corna S, Musazzi L, Lee FS, Tongiorgi E, Popoli M. Expression and Dendritic Trafficking of BDNF-6 Splice Variant are Impaired in Knock-In Mice Carrying Human BDNF Val66Met Polymorphism. Int J Neuropsychopharmacol 2015; 18:pyv069. [PMID: 26108221 PMCID: PMC4675980 DOI: 10.1093/ijnp/pyv069] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/12/2015] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The human Val66Met polymorphism in brain-derived neurotrophic factor (BDNF), a key factor in neuroplasticity, synaptic function, and cognition, has been implicated in the pathophysiology of neuropsychiatric and neurodegenerative disorders. BDNF is encoded by multiple transcripts with distinct regulation and localization, but the impact of the Val66Met polymorphism on BDNF regulation remains unclear. METHODS In BDNF Val66Met knock-in mice, which recapitulate the phenotypic hallmarks of individuals carrying the BDNF(Met) allele, we measured expression levels, epigenetic changes at promoters, and dendritic trafficking of distinct BDNF transcripts using quantitative PCR, chromatin immunoprecipitation (ChIP), and in situ hybridization. RESULTS BDNF-4 and BDNF-6 transcripts were reduced in BDNF(Met/Met) mice, compared with BDNF(Val/Val) mice. ChIP for acetyl-histone H3, a marker of active gene transcription, and trimethyl-histone-H3-Lys27 (H3K27me3), a marker of gene repression, showed higher H3K27me3 binding to exon 5, 6, and 8 promoters in BDNF(Met/Met). The H3K27 methyltransferase enhancer of zeste homolog 2 (EZH2) is involved in epigenetic regulation of BDNF expression, because in neuroblastoma cells BDNF expression was increased both by short interference RNA for EZH2 and incubation with 3-deazaneplanocin A, an inhibitor of EZH2. In situ hybridization for BDNF-2, BDNF-4, and BDNF-6 after pilocarpine treatment showed that BDNF-6 transcript was virtually absent from distal dendrites of the CA1 and CA3 regions in BDNF(Met/Met) mice, while no changes were found for BDNF-2 and BDNF-4. CONCLUSIONS Impaired BDNF expression and dendritic targeting in BDNF(Met/Met) mice may contribute to reduced regulated secretion of BDNF at synapses, and may be a specific correlate of pathology in individuals carrying the Met allele.
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Affiliation(s)
- Alessandra Mallei
- Laboratory of Neuropsychopharmacology and Functional Neurogenomics - Dipartimento di Scienze Farmacologiche e Biomolecolari and Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milano, Italy (Drs Mallei, Ieraci, Corna, Musazzi, and Popoli); Department of Life Sciences, BRAIN Centre for Neuroscience, University of Trieste, Trieste, Italy (Drs Baj and Tongiorgi); Department of Psychiatry, Weill Cornell Medical College Cornell University, New York, NY (Dr Lee).
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5
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Reinhart V, Bove SE, Volfson D, Lewis DA, Kleiman RJ, Lanz TA. Evaluation of TrkB and BDNF transcripts in prefrontal cortex, hippocampus, and striatum from subjects with schizophrenia, bipolar disorder, and major depressive disorder. Neurobiol Dis 2015; 77:220-7. [PMID: 25796564 DOI: 10.1016/j.nbd.2015.03.011] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/12/2015] [Accepted: 03/12/2015] [Indexed: 02/08/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) signaling is integral to a range of neural functions, including synaptic plasticity and exhibits activity-dependent regulation of expression. As altered BDNF signaling has been implicated in multiple psychiatric diseases, here we report a quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis of mRNAs encoding TrkB, total BDNF, and the four most abundant BDNF transcripts (I, IIc, IV, and VI) in postmortem tissue from matched tetrads of subjects with schizophrenia, bipolar disorder, or major depressive disorder (MDD) and healthy comparison subjects. In all three regions examined, dorsolateral prefrontal cortex (DLPFC), associative striatum and hippocampus, total BDNF mRNA levels did not differ in any disease state. In DLPFC, BDNF IIc was significantly lower in schizophrenia relative to healthy comparison subjects. In hippocampus, BDNF I, IIc, and VI were lower in subjects with both schizophrenia and bipolar disorder relative to comparison subjects. In striatum, TrkB mRNA was lower in bipolar disorder and MDD, while BDNF IIc was elevated in MDD, relative to comparison subjects. These data highlight potential alterations in BDNF signaling in the corticohippocampal circuit in schizophrenia, and within the striatum in mood disorders. Novel therapies aimed at improving BDNF-TrkB signaling may therefore have potential to impact on a range of psychiatric disorders.
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Affiliation(s)
| | | | | | - David A Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robin J Kleiman
- Translational Neuroscience Center, Boston Children's Hospital, Boston, MA, USA
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6
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Koskimäki J, Matsui N, Umemori J, Rantamäki T, Castrén E. Nimodipine activates TrkB neurotrophin receptors and induces neuroplastic and neuroprotective signaling events in the mouse hippocampus and prefrontal cortex. Cell Mol Neurobiol 2015; 35:189-96. [PMID: 25204460 DOI: 10.1007/s10571-014-0110-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/01/2014] [Indexed: 12/14/2022]
Abstract
The L-type calcium channel blocker nimodipine improves clinical outcome produced by delayed cortical ischemia or vasospasm associated with subarachnoid hemorrhage. While vasoactive mechanisms are strongly implicated in these therapeutic actions of nimodipine, we sought to test whether nimodipine might also regulate neurotrophic and neuroplastic signaling events associated with TrkB neurotrophin receptor activation. Adult male mice were acutely treated with vehicle or nimodipine (10 mg/kg, s.c., 1.5 h) after which the phosphorylation states of TrkB, cyclic-AMP response element binding protein (CREB), protein kinase B (Akt), extracellular regulated kinase (ERK), mammalian target of rapamycin (mTor) and p70S6 kinase (p70S6k) from prefrontal cortex and hippocampus were assessed. Nimodipine increased the phosphorylation of the TrkB catalytic domain and the phosphoslipase-Cγ1 (PLCγ1) domain, whereas phosphorylation of the TrkB Shc binding site remained unaltered. Nimodipine-induced TrkB phosphorylation was associated with increased phosphorylation levels of Akt and CREB in the prefrontal cortex and the hippocampus whereas phosphorylation of ERK, mTor and p70S6k remained unaltered. Nimodipine-induced TrkB signaling was not associated with changes in BDNF mRNA or protein levels. These nimodipine-induced changes on TrkB signaling mimic those produced by antidepressant drugs and thus propose common mechanisms and long-term functional consequences for the effects of these medications. This work provides a strong basis for investigating the role of TrkB-associated signaling underlying the neuroprotective and neuroplastic effects of nimodipine in translationally relevant animal models of brain trauma or compromised synaptic plasticity.
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Affiliation(s)
- Janne Koskimäki
- Neuroscience Center, University of Helsinki, P.O. Box 56 (Viikinkaari 4), 00014, Helsinki, Finland
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7
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Vanevski F, Xu B. HuD interacts with Bdnf mRNA and is essential for activity-induced BDNF synthesis in dendrites. PLoS One 2015; 10:e0117264. [PMID: 25692578 PMCID: PMC4332865 DOI: 10.1371/journal.pone.0117264] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 12/23/2014] [Indexed: 12/19/2022] Open
Abstract
Highly specific activity-dependent neuronal responses are necessary for modulating synapses to facilitate learning and memory. We present evidence linking a number of important processes involved in regulating synaptic plasticity, suggesting a mechanistic pathway whereby activity-dependent signaling, likely through protein kinase C (PKC)-mediated phosphorylation of HuD, can relieve basal repression of Bdnf mRNA translation in dendrites, allowing for increased TrkB signaling and synaptic remodeling. We demonstrate that the neuronal ELAV family of RNA binding proteins associates in vivo with several Bdnf mRNA isoforms present in the adult brain in an activity-dependent manner, and that one member, HuD, interacts directly with sequences in the long Bdnf 3' untranslated region (3'UTR) and co-localizes with Bdnf mRNA in dendrites of hippocampal neurons. Activation of PKC leads to increased dendritic translation of mRNAs containing the long Bdnf 3'UTR, a process that is dependent on the presence of HuD and its phosphorylation at threonine residues 149 and/or 165. Thus, we found a direct effect of HuD on regulating translation of dendritic Bdnf mRNAs to mediate local and activity-dependent increases in dendritic BDNF synthesis.
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Affiliation(s)
- Filip Vanevski
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, D.C., United States of America
| | - Baoji Xu
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, D.C., United States of America
- * E-mail:
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8
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Callaghan CK, Kelly ÁM. Neurotrophins play differential roles in short and long-term recognition memory. Neurobiol Learn Mem 2013; 104:39-48. [DOI: 10.1016/j.nlm.2013.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/29/2013] [Accepted: 04/30/2013] [Indexed: 12/25/2022]
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Abstract
It has been suggested that long-term modifications of synaptic transmission constitute the foundation of the processes by which information is stored in the central nervous system. A group of proteins called neurotrophins are considered powerful molecular mediators in central synaptic plasticity. Among these, brain-derived neurotrophic factor (BDNF) as well as neurotrophin-3 (NT-3) have emerged as having key roles in the neurobiological mechanisms related to learning and memory. In this chapter, we review the studies that have represented a significant step forward in understanding the role played by BDNF and NT-3 in long-term synaptic plasticity. The effects of BDNF and NT-3 on synaptic plasticity can be of a permissive nature, establishing the conditions under which plastic changes can take place, or it may be instructive, directly modifying the communication and morphology of synapses. The actions carried out by BDNF include its capacity to contribute to the stabilization and maturation of already-existing synapses, as well as to generate new synaptic contacts. One important finding that highlights the participation of these neurotrophins in synaptic plasticity is the observation that adding BDNF or NT-3 gives rise to drastic long-term increases in synaptic transmission, similar to the long-term potentiation in the hippocampus and neocortex of mammals. Because neurotrophins modulate both the electrical properties and the structural organization of the synapse, these proteins have been considered important biological markers of learning and memory processes.
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Affiliation(s)
- Andrea Gómez-Palacio-Schjetnan
- División de Investigación y Estudios de Posgrado, Facultad de Psicologia, Universidad Nacional Autónoma de México, 04510, México, D.F., Mexico
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10
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Wang FJ, Li CM, Hou XH, Wang R, Zhang LM. Selective Upregulation of Brain-Derived Neurotrophic Factor (BDNF) Transcripts and BDNF Direct Induction of Activity Independent N-Methyl-D-Aspartate Currents in Temporal Lobe Epilepsy Patients with Hippocampal Sclerosis. J Int Med Res 2011; 39:1358-68. [PMID: 21986136 DOI: 10.1177/147323001103900422] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays a critical role in many aspects of neuronal biology and hippocampal physiology and pathology, and has been implicated as a potential therapeutic target in temporal lobe epilepsy (TLE). BDNF total mRNA and its six transcripts were compared in the hippocampal tissue of TLE patients with or without hippocampal sclerosis (HS) by real-time fluorescence quantitative polymerase chain reaction. Excitatory actions induced by BDNF on hippocampal cells were investigated by whole-cell patch-clamp recordings. Statistically significant increases in three human BDNF mRNA transcripts were observed in TLE patients with HS compared with those without HS (transcripts 2, 3 and 5 exhibited 2.1-, 2.3-and 4.1-fold increases, respectively); there were no significant increases in other transcripts. BDNF directly induced N-methyl-d-aspartate currents in dentate granule cells of TLE patients with HS. These results demonstrated that BDNF transcripts were selectively upregulated in TLE patients with HS compared with those without HS. Moreover, BDNF induced excitability of dentate granule cells in TLE patients with HS.
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Affiliation(s)
- FJ Wang
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - CM Li
- Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - XH Hou
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - R Wang
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - LM Zhang
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, China
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Abstract
Calcium-response factor (CaRF) is a unique DNA-binding protein first recognized as a transcription factor for its role in modulating transcription of the gene encoding Brain-Derived Neurotrophic Factor (BDNF) in neurons. Here I review evidence for the biological functions and transcriptional targets of CaRF in the brain and discuss potential mechanisms by which calcium-activated signaling pathways may modulate CaRF-dependent transcription. These data paint an emerging picture of CaRF as a regulatory nexus for signaling pathways that control aspects of synaptic development and neuronal function.
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Affiliation(s)
- Anne E West
- Department of Neurobiology, Box 3209, Duke University Medical Center, Durham, NC 27710, USA.
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Kawaai K, Tominaga-Yoshino K, Urakubo T, Taniguchi N, Kondoh Y, Tashiro H, Ogura A, Tashiro T. Analysis of gene expression changes associated with long-lasting synaptic enhancement in hippocampal slice cultures after repetitive exposures to glutamate. J Neurosci Res 2010; 88:2911-22. [PMID: 20568283 DOI: 10.1002/jnr.22457] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have previously shown that repetitive exposures to glutamate (100 muM, 3 min, three times at 24-hr intervals) induced a long-lasting synaptic enhancement accompanied by synaptogenesis in rat hippocampal slice cultures, a phenomenon termed RISE (for repetitive LTP-induced synaptic enhancement). To investigate the molecular mechanisms underlying RISE, we first analyzed the time course of gene expression changes between 4 hr and 12 days after repetitive stimulation using an original oligonucleotide microarray: "synaptoarray." The results demonstrated that changes in the expression of synapse-related genes were induced in two time phases, an early phase of 24-96 hr and a late phase of 6-12 days after the third stimulation. Comprehensive screening at 48 hr after the third stimulation using commercially available high-density microarrays provided candidate genes responsible for RISE. From real-time PCR analysis of these and related genes, two categories of genes were identified, 1) genes previously reported to be induced by physiological as well as epileptic activity (bdnf, grm5, rgs2, syt4, ania4/carp/dclk) and 2) genes involved in cofilin-based regulation of actin filament dynamics (ywhaz, ssh1l, pak4, limk1, cfl). In the first category, synaptotagmin 4 showed a third stimulation-specific up-regulation also at the protein level. Five genes in the second category were coordinately up-regulated by the second stimulation, resulting in a decrease in cofilin phosphorylation and an enhancement of actin filament dynamics. In contrast, after the third stimulation, they were differentially regulated to increase cofilin phosphorylation and enhance actin polymerization, which may be a key step leading to the establishment of RISE.
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Affiliation(s)
- Katsuhiro Kawaai
- Department of Chemistry and Biological Science, School of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan
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13
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Knipper M, Zimmermann U, Müller M. Molecular aspects of tinnitus. Hear Res 2010; 266:60-9. [DOI: 10.1016/j.heares.2009.07.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 07/28/2009] [Accepted: 07/28/2009] [Indexed: 01/18/2023]
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Gil-Bea FJ, Solas M, Mateos L, Winblad B, Ramírez MJ, Cedazo-Mínguez A. Cholinergic hypofunction impairs memory acquisition possibly through hippocampal Arc and BDNF downregulation. Hippocampus 2010; 21:999-1009. [PMID: 20865740 DOI: 10.1002/hipo.20812] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2010] [Indexed: 12/25/2022]
Abstract
Recent evidence suggests that activity-regulated cytoskeleton associated protein (Arc) and brain-derived neurotrophic factor (BDNF) are key players in the cellular mechanisms that trigger synaptic changes and memory consolidation. Cholinergic deafferentiation of hippocampus has been largely shown to induce memory impairments in different behavioral tasks. However, the mechanisms underlying cholinergic-induced memory formation remain unclear. The role of hippocampal cholinergic denervation on synaptic consolidation and further acquisition of spatial memory was hereby examined by analyzing Arc and BDNF in standard environment and after behavioral training in Morris water maze (MWM). In standard environment, a cholinergic hypofunction induced by the toxin (192) IgG-saporin led to significant decreases in Arc protein and mRNA as well as in BDNF. Lesioned rats subjected to MWM showed a worse acquisition performance that was reversed after galantamine treatment. Recovery of memory acquisition was accompanied by normalization of Arc and BDNF levels in hippocampus. Stimulation of muscarinic, but not nicotinic receptors, in hippocampal primary neurons caused a rapid induction of Arc production. These data suggest that cholinergic denervation of hippocampus leads to deficits in muscarinic-dependent induction of Arc and a subsequent impairment of spatial memory acquisition.
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Affiliation(s)
- Francisco J Gil-Bea
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, Karolinska Institutet, Stockholm, Sweden.
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Kandratavicius L, Monteiro MR, Silva RADVD, Leite JP. Neurotrofinas na epilepsia do lobo temporal. ACTA ACUST UNITED AC 2010. [DOI: 10.1590/s1676-26492010000100002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUÇÃO: A neurotrofinas NGF, BDNF, NT-3 e NT-4 são os principais representantes da família das neurotrofinas no sistema nervoso central de mamíferos. Estão presentes em estágios específicos do crescimento e sobrevivência neuronal como a divisão celular, diferenciação e axogênese e também nos processos naturais de morte celular neuronal. A atividade biológica das neurotrofinas é mediada pelos receptores de tropomiosina quinase Trk. NGF ativa principalmente os receptores TrkA, BDNF e NT-4 interagem com os receptores TrkB e NT-3 com TrkC. Todas as NTs também podem se ligar, com menor afinidade, ao receptor p75NTR. Nesta breve revisão serão levantadas as principais evidências sobre o papel e expressão das principais neurotrofinas no hipocampo, com ênfase nas alterações que ocorrem em modelos animais de epilepsia. RESULTADOS: As neurotrofinas parecem ter um papel chave na plasticidade sináptica relacionada à epilepsia, onde elas poderiam agir tanto como fatores promotores da epileptogênese quanto como substâncias anti-epiléptogênicas endógenas. Além disso a expressão dos genes que codificam os fatores neurotróficos e seus receptores pode ser alterada pela atividade de crises em diversos modelos de epilepsia. CONCLUSÃO: Vários estudos têm demonstrado a relação entre a expressão das neurotrofinas e as alterações na plasticidade dos circuitos neuronais que ocorrem após danos cerebrais, tais como a epilepsia. O conhecimento das alterações na expressão das neurotrofinas na plasticidade neuronal pode nos auxiliar a entender como estas moléculas participam dos mecanismos epileptogênicos e dessa forma, dar início ao estudo de novas terapias e ao desenvolvimento de novas drogas que auxiliem no tratamento da epilepsia.
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Conti G, Gale K, Kondratyev A. Immunohistochemical evaluation of the protein expression of nerve growth factor and its TrkA receptor in rat limbic regions following electroshock seizures. Neurosci Res 2009; 65:201-9. [PMID: 19596387 DOI: 10.1016/j.neures.2009.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 06/26/2009] [Accepted: 07/01/2009] [Indexed: 01/01/2023]
Abstract
Repeated (but not acute) exposure to brief, non-injurious seizures evoked by minimal electroconvulsive shock (ECS) decreases neuronal death in limbic system and increases mRNA levels for nerve growth factor (NGF). Thus, the induction of NGF is a potential mechanism for the neuroprotection evoked by repeated ECS. The neuroprotective action of NGF is mediated by the TrkA receptor. This study determined whether repeated ECS exposure increased TrkA and NGF protein levels. To determine the functional significance of changes in these proteins, we compared the effects of ECS given daily either for 7 days (chronic ECS) or for 1 day (acute ECS). After chronic ECS, upregulation of both NGF and TrkA was found in perirhinal cortex, thalamus, and amygdala. In hippocampus, TrkA was upregulated in CA2, CA3 and CA4. NGF increase in hippocampus was found in CA1 and dentate gyrus. In frontal cortex and substantia innominata, an increase in NGF (but not in TrkA) was found. In most brain regions, TrkA and NGF remained unchanged after acute ECS. Our results demonstrate that repeated exposure to ECS causes an upregulation of TrkA and NGF proteins in several limbic areas in which neuroprotective effects are observed suggesting that NGF contributes to ECS-evoked neuroprotection.
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Affiliation(s)
- Giuseppe Conti
- Department of Pharmacology, Georgetown University, Washington, DC 20057, USA
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17
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Zhang HN, Ko MC. Seizure activity involved in the up-regulation of BDNF mRNA expression by activation of central mu opioid receptors. Neuroscience 2009; 161:301-10. [PMID: 19303919 DOI: 10.1016/j.neuroscience.2009.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 03/07/2009] [Accepted: 03/10/2009] [Indexed: 01/02/2023]
Abstract
Chemical-induced seizures up-regulated brain-derived neurotrophic factor (BDNF) mRNA expression. Intracerebroventricular (i.c.v.) administration of endogenous opioids preferentially activating mu opioid receptor (MOR) could also increase BDNF mRNA expression. The aim of this study was to determine to what extent i.c.v. administration of synthetic MOR-selective agonists in rats can modulate both seizure activity and up-regulation of BDNF mRNA expression. Effects and potencies of i.c.v. administration of morphine and [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO), were directly investigated by scoring behavioral seizures and measuring BDNF mRNA expression. In addition, effects of the opioid receptor antagonist naloxone and antiepileptic drugs, diazepam, phenobarbital, and valproate, on i.c.v. MOR agonist-induced behavioral seizures and up-regulation of BDNF mRNA expression were determined. A single i.c.v. administration of morphine (10-100 microg) or DAMGO (0.15-1.5 microg) dose-dependently elicited behavioral seizures and increased BDNF mRNA expression in the widespread brain regions. However, s.c. administration of MOR agonists neither produced behavioral seizures nor increased BDNF mRNA expression. Pretreatment with naloxone 1 mg/kg significantly reduced behavioral seizure scores and the up-regulation of BDNF mRNA expression elicited by i.c.v. morphine or DAMGO. Similarly, diazepam 10 mg/kg and phenobarbital 40 mg/kg significantly blocked i.c.v. MOR agonist-induced actions. Pretreatment with valproate 300 mg/kg only attenuated behavioral seizures, but it did not affect morphine-induced increase of BDNF mRNA expression. This study provides supporting evidence that seizure activity plays an important role in the up-regulation of BDNF mRNA expression elicited by central MOR activation and that decreased inhibitory action of GABAergic system through the modulation on GABA receptor synaptic function by central MOR activation is involved in its regulation of BDNF mRNA expression.
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Affiliation(s)
- H N Zhang
- Department of Biomedical Engineering, College of Engineering, 1101 Beal Avenue, University of Michigan, Ann Arbor, MI 48109, USA
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18
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Arai AC. The role of kisspeptin and GPR54 in the hippocampus. Peptides 2009; 30:16-25. [PMID: 18765263 DOI: 10.1016/j.peptides.2008.07.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 07/26/2008] [Accepted: 07/31/2008] [Indexed: 11/21/2022]
Abstract
The granule cells of the dentate gyrus form the input stage of the hippocampal trisynaptic circuit and their function is strongly influenced by peptidergic systems. GPR54 is highly and discretely expressed in these cells. We have found that activation of GPR54 with kisspeptin-10 causes a rapid and large increase in the amplitude of excitatory synaptic responses in granule cells, without changing membrane properties. The effect was suppressed by the G-protein inhibitor GDP-beta-S and the calcium chelator BAPTA, and analysis of miniature EPSCs revealed an increase in mean amplitude but not event frequency, indicating that GPR54 and the mechanisms for enhancing EPSCs are postsynaptic, possibly involving changes in AMPA receptor number or conductance. The kisspeptin-induced synaptic potentiation was abolished by inhibitors of ERK1/2, tyrosine kinase, and CaMKII. RT-PCR experiments showed that KiSS-1 is expressed in the dentate gyrus. KiSS-1 mRNA was significantly increased by seizure activity in rats and when neuronal activity in organotypic hippocampal slice cultures was enhanced by kainate or picrotoxin, while mRNA for GPR54 remained essentially unchanged. These results suggest that kisspeptin may be locally synthesized and act as an autocrine factor. In separate experiments, hippocampal KiSS-1 mRNA in male rats was increased after gonadectomy. In summary, kisspeptin is a novel endogenous factor which is dynamically regulated by neuronal activity and which, in marked distinction from other neuropeptides, increases synaptic transmission in dentate granule cells through signaling cascades possibly linked to the MAP kinase system. This novel peptide system may play a role in cognition and in the pathogenesis of epilepsy.
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Affiliation(s)
- Amy C Arai
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, USA.
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Gene expression profiles of neurotrophic factors in rat cultured spinal cord cells under cyclic tensile stress. Spine (Phila Pa 1976) 2008; 33:2596-604. [PMID: 18981959 DOI: 10.1097/brs.0b013e31818917af] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An experimental study to investigate the in vitro gene expression of neurotrophic factors and receptors in cultured rat spinal cord cells subjected to cyclic mechanical stretch forces. OBJECTIVE We evaluated in vitro expression of neurotrophic factors and receptors in cultured rat spinal cord cells under cyclic tensile stress. SUMMARY OF BACKGROUND DATA Application of compressive mechanical stress to the spinal cord results in multiple changes making it difficult to examine the expression of neurotrophic factors and their receptors. There are no in vitro studies that investigated the biologic responses of cultured spinal cord cells to tensile stress. METHODS Spinal cord cells were isolated for culture from 15-day Sprague-Dawley rat embryos. We used the FX3000 Flexercell Strain Unit to induce mechanical stress. We analyzed the effects of mechanical stress on cell morphology, mRNA expression levels of various neurotrophic factors, and their immunoreactivities at 0, 2, 6, 12, 24, and 36 hours. RESULTS Tensile stress for 6 hours resulted in reduction of spinal cord cells and loss of neurites. Cells that survived 24-hours stress showed swollen irregular-shaped soma, bleb formation, and fragmented neurites. The cell survival rate decreased, whereas lactate dehydrogenase release increased significantly at 6 hours. There were significant increases in mRNA expression levels of nerve growth factor, brain-derived neurotrophic factor, trkB, p75 neurotrophin receptor (p75), glial cell line-derived neurotrophic factor, and caspase-9 during the early period after application of tensile stress. CONCLUSION Our results suggest survival of spinal cord neuronal cells under injurious tensile stress with increased synthesis and utilization of several neurotrophic factors, receptors, and expression of proteins related to cell apoptosis.
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20
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Factors that regulate KiSS1 gene expression in the hippocampus. Brain Res 2008; 1243:10-8. [PMID: 18834866 DOI: 10.1016/j.brainres.2008.09.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 09/09/2008] [Accepted: 09/10/2008] [Indexed: 01/11/2023]
Abstract
Kisspeptin is a C-terminally amidated peptide encoded by the KiSS1 gene. The peptide and its receptor GPR54 are abundant in the hypothalamus and have been implicated as gatekeepers for the onset of puberty and the development of the reproductive system. Interestingly, GPR54 is also highly expressed in granule cells of the hippocampal dentate gyrus, and in a previous study we showed that kisspeptin enhances excitatory synaptic transmission in these cells. The present study examined how expression of KiSS1 and GPR54 is regulated in rat hippocampus, using in vivo and in vitro preparations. In animals, a 3 h period of kainate-induced seizures significantly altered expression of both genes. KiSS1 mRNA showed a 3-4 fold increase which peaked 1-3 days post-seizure and subsided after one week. GPR54 mRNA, on the other hand, was reduced by 20-30% at 6-24 h. In organotypic hippocampal slice cultures, brief exposure to kainate produced a significant increase in KiSS1 mRNA with a time course comparable to that in vivo, and the effect was blocked by tetrodotoxin and CNQX. Chronic (7-day) treatment with picrotoxin, which induced a persistent four-fold increase in spike activity in multi-electrode recordings, caused a similar size but more persistent upregulation in KiSS1 mRNA. As in other studies, kainate and picrotoxin induced an upsurge in BDNF expression, but BDNF mRNA was also significantly increased when slice cultures were treated with kisspeptin. Taken together, KiSS1 expression is upregulated by neuronal activity and activation of GPR54 by kisspeptin may in turn contribute to sustain basal BDNF levels required for hippocampal function. In additional experiments, KiSS1 mRNA was found to be increased after orchidectomy and thus expression may be regulated also by gonadal hormones.
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Status epilepticus induces a TrkB to p75 neurotrophin receptor switch and increases brain-derived neurotrophic factor interaction with p75 neurotrophin receptor: An initial event in neuronal injury induction. Neuroscience 2008; 154:978-93. [DOI: 10.1016/j.neuroscience.2008.04.038] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 04/03/2008] [Accepted: 04/04/2008] [Indexed: 01/12/2023]
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22
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McKee AE, Neretti N, Carvalho LE, Meyer CA, Fox EA, Brodsky AS, Silver PA. Exon expression profiling reveals stimulus-mediated exon use in neural cells. Genome Biol 2008; 8:R159. [PMID: 17683528 PMCID: PMC2374990 DOI: 10.1186/gb-2007-8-8-r159] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 06/12/2007] [Accepted: 08/02/2007] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Neuronal cells respond to changes in intracellular calcium ([Ca2+]i) by affecting both the abundance and architecture of specific mRNAs. Although calcium-induced transcription and transcript variation have both been recognized as important sources of gene regulation, the interplay between these two phenomena has not been evaluated on a genome-wide scale. RESULTS Here, we show that exon-centric microarrays can be used to resolve the [Ca2+]i-modulated gene expression response into transcript-level and exon-level regulation. Global assessments of affected transcripts reveal modulation within distinct functional gene categories. We find that transcripts containing calcium-modulated exons exhibit enrichment for calcium ion binding, calmodulin binding, plasma membrane associated, and metabolic proteins. Additionally, we uncover instances of regulated exon use in potassium channels, neuroendocrine secretory proteins and metabolic enzymes, and demonstrate that regulated changes in exon expression give rise to distinct transcript variants. CONCLUSION Our findings connect extracellular stimuli to specific exon behavior, and suggest that changes in transcript and exon abundance are reflective of a coordinated gene expression response to elevated [Ca2+]i. The technology we describe here lends itself readily to the resolution of stimulus-induced gene expression at both the transcript and exon levels.
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Affiliation(s)
- Adrienne E McKee
- Department of Systems Biology, 200 Longwood Avenue, Harvard Medical School, Boston, Massachusetts 02115, USA.
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23
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Hu Y, Russek SJ. BDNF and the diseased nervous system: a delicate balance between adaptive and pathological processes of gene regulation. J Neurochem 2008; 105:1-17. [PMID: 18208542 DOI: 10.1111/j.1471-4159.2008.05237.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is clear that brain-derived neurotrophic factor (BDNF) plays a crucial role in organizing the response of the genome to dynamic changes in the extracellular environment that enable brain plasticity. BDNF has emerged as one of the most important signaling molecules for the developing nervous system as well as the impaired nervous system, and multiple diseases, such as Alzheimer's, Parkinson's, Huntington's, epilepsy, Rett's syndrome, and psychiatric depression, are linked by their association with potential dysregulation of BDNF-driven signal transduction programs. These programs are responsible for controlling the amount of activated transcription factors, such as cAMP response element binding protein, that coordinate the expression of multiple brain proteins, like ion channels and early growth response factors, whose job is to maintain the balance of excitation and inhibition in the nervous system. In this review, we will explore the evidence for BDNF's role in gene regulation side by side with its potential role in the etiology of neurological diseases. It is hoped that by bringing the datasets together in these diverse fields we can help develop the foundation for future studies aimed at understanding basic principles of gene regulation in the nervous system and how they can be harnessed to develop new therapeutic opportunities.
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Affiliation(s)
- Yinghui Hu
- Department of Pharmacology and Experimental Therapeutics, Laboratory of Translational Epilepsy, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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24
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Chiaruttini C, Sonego M, Baj G, Simonato M, Tongiorgi E. BDNF mRNA splice variants display activity-dependent targeting to distinct hippocampal laminae. Mol Cell Neurosci 2008; 37:11-9. [DOI: 10.1016/j.mcn.2007.08.011] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 08/06/2007] [Accepted: 08/16/2007] [Indexed: 12/29/2022] Open
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Lubin FD, Ren Y, Xu X, Anderson AE. Nuclear factor-kappa B regulates seizure threshold and gene transcription following convulsant stimulation. J Neurochem 2007; 103:1381-95. [PMID: 17727632 DOI: 10.1111/j.1471-4159.2007.04863.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We evaluated a role for the nuclear factor-kappa B (NF-kappaB) pathway in the regulation of seizure susceptibility and transcriptional activation during prolonged, continuous seizures (status epilepticus). Using two functionally distinct NF-kappaB inhibitors we observed a decrease in latency to onset of kainate-induced seizures and status epilepticus. To assess NF-kappaB transcriptional activation, we evaluated inhibitor kappa B alpha (IkappaBalpha) and brain-derived neurotrophic factor (bdnf) gene targets. Inhibition of the NF-kappaB signaling pathway significantly attenuated the increases in IkappaBalpha and bdnf mRNA levels that occurred during prolonged seizure activity, suggesting that the NF-kappaB pathway was involved in the up-regulation of these transcripts during status epilepticus. DNA-binding studies and chromatin immunoprecipitation assays using hippocampal extracts from animals with status epilepticus revealed that NF-kappaB subunits were associated with the candidate kappaB-binding elements within promoter 1 of the bdnf gene. The pattern of association was different for the p50 and p65 subunits supporting complex NF-kappaB modifications within promoter 1. In summary, our findings provide additional insights into the role of NF-kappaB transcriptional regulation in hippocampus following status epilepticus and suggest that NF-kappaB pathway activation contributes to seizure susceptibility.
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Affiliation(s)
- Farah D Lubin
- Cain Foundation Laboratories, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA, and Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
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Tan J, Rüttiger L, Panford-Walsh R, Singer W, Schulze H, Kilian SB, Hadjab S, Zimmermann U, Köpschall I, Rohbock K, Knipper M. Tinnitus behavior and hearing function correlate with the reciprocal expression patterns of BDNF and Arg3.1/arc in auditory neurons following acoustic trauma. Neuroscience 2007; 145:715-26. [PMID: 17275194 DOI: 10.1016/j.neuroscience.2006.11.067] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 11/28/2006] [Accepted: 11/30/2006] [Indexed: 12/24/2022]
Abstract
The molecular changes following sensory trauma and the subsequent response of the CNS are poorly understood. We focused on finding a molecular tool for monitoring the features of excitability which occur following acoustic trauma to the auditory system. Of particular interest are genes that alter their expression pattern during activity-induced changes in synaptic efficacy and plasticity. The expression of brain-derived neurotrophic factor (BDNF), the activity-dependent cytoskeletal protein (Arg3.1/arc), and the immediate early gene c-Fos were monitored in the peripheral and central auditory system hours and days following a traumatic acoustic stimulus that induced not only hearing loss but also phantom auditory perception (tinnitus), as shown in rodent animal behavior models. A reciprocal responsiveness of activity-dependent genes became evident between the periphery and the primary auditory cortex (AI): as c-Fos and BDNF exon IV expression was increased in spiral ganglion neurons, Arg3.1/arc and (later on) BDNF exon IV expression was reduced in AI. In line with studies indicating increased spontaneous spike activity at the level of the inferior colliculus (IC), an increase in BDNF and GABA-positive neurons was seen in the IC. The data clearly indicate the usefulness of Arg3.1/arc and BDNF for monitoring trauma-induced activity changes and the associated putative plasticity responses in the auditory system.
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Affiliation(s)
- J Tan
- University of Tübingen, Department of Otorhinolaryngology, Hearing Research Center Tübingen, Molecular Neurobiology, Elfriede-Aulhorn-Strasse 5, 72076 Tübingen, Germany
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27
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Tóth K, Wittner L, Urbán Z, Doyle WK, Buzsáki G, Shigemoto R, Freund TF, Maglóczky Z. Morphology and synaptic input of substance P receptor-immunoreactive interneurons in control and epileptic human hippocampus. Neuroscience 2007; 144:495-508. [PMID: 17097238 PMCID: PMC2753206 DOI: 10.1016/j.neuroscience.2006.09.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 09/22/2006] [Accepted: 09/22/2006] [Indexed: 01/08/2023]
Abstract
Substance P (SP) is known to be a peptide that facilitates epileptic activity of principal cells in the hippocampus. Paradoxically, in other models, it was found to be protective against seizures by activating substance P receptor (SPR)-expressing interneurons. Thus, these cells appear to play an important role in the generation and regulation of epileptic seizures. The number, distribution, morphological features and input characteristics of SPR-immunoreactive cells were analyzed in surgically removed hippocampi of 28 temporal lobe epileptic patients and eight control hippocampi in order to examine their changes in epileptic tissues. SPR is expressed in a subset of inhibitory cells in the control human hippocampus, they are multipolar interneurons with smooth dendrites, present in all hippocampal subfields. This cell population is considerably different from SPR-positive cells of the rat hippocampus. The CA1 (cornu Ammonis subfield 1) region was chosen for the detailed morphological analysis of the SPR-immunoreactive cells because of its extreme vulnerability in epilepsy. The presence of various neurochemical markers identifies functionally distinct interneuron types, such as those responsible for perisomatic, dendritic or interneuron-selective inhibition. We found considerable colocalization of SPR with calbindin but not with parvalbumin, calretinin, cholecystokinin and somatostatin, therefore we suppose that SPR-positive cells participate mainly in dendritic inhibition. In the non-sclerotic CA1 region they are mainly preserved, whereas their number is decreased in the sclerotic cases. In the epileptic samples their morphology is considerably altered, they possessed more dendritic branches, which often became beaded. Analyses of synaptic coverage revealed that the ratio of symmetric synaptic input of SPR-immunoreactive cells has increased in epileptic samples. Our results suggest that SPR-positive cells are preserved while principal cells are present in the CA1 region, but show reactive changes in epilepsy including intense branching and growth of their dendritic arborization.
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Affiliation(s)
- Kinga Tóth
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450, Budapest, Hungary
| | - Lucia Wittner
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450, Budapest, Hungary
| | - Zoltán Urbán
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450, Budapest, Hungary
| | - Werner K. Doyle
- Department of Neurosurgery, New York University, School of Medicine, New York, NY 10016, USA
| | - György Buzsáki
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ 07102, USA
| | - Ryuichi Shigemoto
- Division of Cerebral Structure, National Institute for Physiological Sciences, Myodaiji, Okazaki 444-8585, Japan
| | - Tamás F. Freund
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450, Budapest, Hungary
| | - Zsófia Maglóczky
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450, Budapest, Hungary
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Simonato M, Tongiorgi E, Kokaia M. Angels and demons: neurotrophic factors and epilepsy. Trends Pharmacol Sci 2006; 27:631-8. [PMID: 17055067 DOI: 10.1016/j.tips.2006.10.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 09/11/2006] [Accepted: 10/09/2006] [Indexed: 12/29/2022]
Abstract
Several lines of evidence indicate that neurotrophic factors (NTFs) could be key causal mediators in the development of acquired epileptic syndromes. Yet the trophic properties of NTFs indicate that they might be used to treat epilepsy-associated damage. Accordingly, different NTFs, or even the same NTF, could produce functionally contrasting effects in the context of epilepsy. Recent experimental evidence begins to shed light on the mechanisms underlying these contrasting effects. Understanding these mechanisms will be instrumental for the development of effective therapies, which must be based on a careful consideration of the biological properties of NTFs. Here, we critically evaluate new information emerging in this area and discuss its implications for clinical treatment.
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Affiliation(s)
- Michele Simonato
- Department of Clinical and Experimental Medicine, Section of Pharmacology, University of Ferrara, Ferrara 44100, Italy.
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Roberts DS, Hu Y, Lund IV, Brooks-Kayal AR, Russek SJ. Brain-derived neurotrophic factor (BDNF)-induced synthesis of early growth response factor 3 (Egr3) controls the levels of type A GABA receptor alpha 4 subunits in hippocampal neurons. J Biol Chem 2006; 281:29431-5. [PMID: 16901909 DOI: 10.1074/jbc.c600167200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Altered function of gamma-aminobutyric acid type A receptors (GABA(A)Rs) in dentate granule cells of the hippocampus has been associated with temporal lobe epilepsy (TLE) in humans and in animal models of TLE. Such altered receptor function (including increased inhibition by zinc and lack of modulation by benzodiazepines) is related, in part, to changes in the mRNA levels of certain GABA(A)R subunits, including alpha4, and may play a role in epileptogenesis. The majority of GABA(A)Rs that contain alpha4 subunits are extra-synaptic due to lack of the gamma2 subunit and presence of delta. However, it has been hypothesized that seizure activity may result in expression of synaptic receptors with altered properties driven by an increased pool of alpha4 subunits. Results of our previous work suggests that signaling via protein kinase C (PKC) and early growth response factor 3 (Egr3) is the plasticity trigger for aberrant alpha4 subunit gene (GABRA4) expression after status epilepticus. We now report that brain derived neurotrophic factor (BDNF) is the endogenous signal that induces Egr3 expression via a PKC/MAPK-dependent pathway. Taken together with the fact that blockade of tyrosine kinase (Trk) neurotrophin receptors reduces basal GABRA4 promoter activity by 50%, our findings support a role for BDNF as the mediator of Egr3-induced GABRA4 regulation in developing neurons and epilepsy and, moreover, suggest that BDNF may alter inhibitory processing in the brain by regulating the balance between phasic and tonic inhibition.
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Affiliation(s)
- Daniel S Roberts
- Laboratory of Molecular Neurobiology, Department of Pharmacology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Lee PR, Cohen JE, Becker KG, Fields RD. Gene expression in the conversion of early-phase to late-phase long-term potentiation. Ann N Y Acad Sci 2006; 1048:259-71. [PMID: 16154938 DOI: 10.1196/annals.1342.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Changes in gene expression associated with different forms of synaptic plasticity in rat hippocampus were investigated. Microarray analysis revealed differential expression of hundreds of genes 30 min after synaptic or antidromic stimulation in different patterns. Results of selected genes were verified by LightCycler RT-PCR. Synaptic activation in a theta burst protocol, which induced long-term potentiation (LTP), increased the mRNA abundance of BDNF-exon 1, but antidromic stimulation in the presence of CNQX, APV, and MCPG (to block glutamatergic synapses) decreased the level of mRNA of this transcript, as did 1 Hz synaptic stimulation. The opposite regulation of this BDNF transcript after firing of the postsynaptic neuron, coincidently or uncorrelated with synaptic firing, is consistent with the effects of BDNF on synaptic transmission, suggesting possible involvement in strengthening and weakening CA1 synapses after correlated versus uncorrelated firing of the postsynaptic neurons with its synaptic inputs. Possible involvement of transcriptional regulation of BDNF in the conversion of early-phase LTP to late-phase LTP are discussed in the context of previous studies by Dudek & Fields (Proc. Natl. Acad. Sci. USA 99: 3962-3967) showing that this conversion can be induced by antidromic stimulation of CA1 neurons in the absence of excitatory synaptic activity.
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Affiliation(s)
- Philip R Lee
- Nervous System Development and Plasticity Section, National Institutes of Health, Bethesda, MD 20892, USA
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Barton ME, Shannon HE. The seizure-related phenotype of brain-derived neurotrophic factor knockdown mice. Neuroscience 2005; 136:563-9. [PMID: 16198489 DOI: 10.1016/j.neuroscience.2005.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 07/24/2005] [Accepted: 08/01/2005] [Indexed: 01/04/2023]
Abstract
The present investigation focused on the seizure-related phenotype of mice lacking one allele of brain-derived neurotrophic factor. Thresholds for producing seizures in brain-derived neurotrophic factor wild-type and brain-derived neurotrophic factor heterozygous mice were compared in several seizure models, including thresholds for electrically-induced clonic, tonic-clonic and 6 Hz limbic seizures, as well as seizures induced chemically by kainate, pilocarpine and pentylenetetrazol. In addition, the rate of amygdala kindling, as well as pre- and post-kindling seizure thresholds was determined. Seizure thresholds for clonic and tonic-clonic electrically induced seizures did not differ between brain-derived neurotrophic factor wild-type and heterozygous mice. However, heterozygous mice had higher thresholds for 6 Hz limbic seizures compared with wild-type mice. Heterozygous mice also required larger doses of kainate to produce limbic seizures. Somewhat surprisingly, heterozygous mice required significantly lower doses of pilocarpine to produce limbic seizures. However, heterozygous mice required a higher dose of pentylenetetrazol to induce twitches, but not clonic seizures, compared with wild-type mice. In addition, heterozygous mice required more current to elicit focal afterdischarges in the amygdala both pre- and post-kindling than did wild-type mice, and, heterozygous mice kindled more slowly than wild-type mice. The present findings provide additional support for the hypothesis that brain-derived neurotrophic factor is involved not only in normal excitability, but may also be involved in abnormal excitability such as occurs in seizure disorders and epileptogenesis.
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Affiliation(s)
- M E Barton
- Neuroscience Research Division, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
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32
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Rattiner LM, Davis M, Ressler KJ. Differential regulation of brain-derived neurotrophic factor transcripts during the consolidation of fear learning. Learn Mem 2004; 11:727-31. [PMID: 15537738 DOI: 10.1101/lm.83304] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) has been implicated as a molecular mediator of learning and memory. The BDNF gene contains four differentially regulated promoters that generate four distinct mRNA transcripts, each containing a unique noncoding 5'-exon and a common 3'-coding exon. This study describes novel evidence for the differential usage of alternative BDNF promoters and 5'-exons during the consolidation of learning. We found a selective increase in BDNF transcripts containing exons I and III in the amygdala 2 h following fear conditioning, while mRNA levels of BDNF exons II and IV remained unchanged. These results provide the first evidence of differential splicing and/or differential BDNF promoter usage in response to a behaviorally relevant learning paradigm.
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Affiliation(s)
- Lisa M Rattiner
- Emory University School of Medicine, Center for Behavioral Neuroscience, Yerkes Research Center, Atlanta, Georgia 30329, USA
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