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Santos AB, Carona A, Ettcheto M, Camins A, Falcão A, Fortuna A, Bicker J. Krüppel-like factors: potential roles in blood-brain barrier dysfunction and epileptogenesis. Acta Pharmacol Sin 2024; 45:1765-1776. [PMID: 38684799 PMCID: PMC11335766 DOI: 10.1038/s41401-024-01285-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/07/2024] [Indexed: 05/02/2024] Open
Abstract
Epilepsy is a chronic and debilitating neurological disorder, known for the occurrence of spontaneous and recurrent seizures. Despite the availability of antiseizure drugs, 30% of people with epilepsy experience uncontrolled seizures and drug resistance, evidencing that new therapeutic options are required. The process of epileptogenesis involves the development and expansion of tissue capable of generating spontaneous recurrent seizures, during which numerous events take place, namely blood-brain barrier (BBB) dysfunction, and neuroinflammation. The consequent cerebrovascular dysfunction results in a lower seizure threshold, seizure recurrence, and chronic epilepsy. This suggests that improving cerebrovascular health may interrupt the pathological cycle responsible for disease development and progression. Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors, encountered in brain endothelial cells, glial cells, and neurons. KLFs are known to regulate vascular function and changes in their expression are associated with neuroinflammation and human diseases, including epilepsy. Hence, KLFs have demonstrated various roles in cerebrovascular dysfunction and epileptogenesis. This review critically discusses the purpose of KLFs in epileptogenic mechanisms and BBB dysfunction, as well as the potential of their pharmacological modulation as therapeutic approach for epilepsy treatment.
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Affiliation(s)
| | - Andreia Carona
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
| | - Miren Ettcheto
- Biomedical Research Networking Center in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- Institute of Neuroscience, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Antoni Camins
- Biomedical Research Networking Center in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- Institute of Neuroscience, Universitat de Barcelona, Barcelona, Spain
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Amílcar Falcão
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
| | - Ana Fortuna
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
| | - Joana Bicker
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal.
- University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal.
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Shirakawa Y, Li H, Inoue Y, Izumi H, Kaga Y, Goto YI, Inoue K, Inagaki M. Abnormality in GABAergic postsynaptic transmission associated with anxiety in Bronx waltzer mice with an Srrm4 mutation. IBRO Neurosci Rep 2024; 16:67-77. [PMID: 38229888 PMCID: PMC10790029 DOI: 10.1016/j.ibneur.2023.12.005] [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: 09/12/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 01/18/2024] Open
Abstract
The homozygous Bronx waltzer (bv) mouse, which shows hearing impairment, also exhibits anxiety accompanied by a reduction in cortical parvalbumin (PV)-positive GABAergic interneurons. Recently, a mutation in splicing factor Ser/Arg repetitive matrix 4 (Srrm4) was found in bv mice. However, the cellular consequences of the Srrm4 mutation for anxiety remain unknown. Here, we tested our hypothesis that bv mutant primarily affects interneurons through a cell-intrinsic pathology that leads to a reduction of interneurons and consequently causes anxiety. We found that the anxiety becomes apparent at 6 weeks of age in bv/bv mice. However, in situ hybridization revealed that Srrm4 is not expressed in interneurons, but rather dominates in pyramidal neurons. In addition, the PV-positive GABAergic interneurons were not reduced in number in the bv/bv cortex when anxiety became evident. However, electrophysiological abnormality of GABAergic transmission from interneurons was concomitantly present. Pharmacological blockage of GABAA receptors revealed increased excitability in bv/bv mice, although no gross change occurred in the expression of an Srrm4-downstream gene, Kcc2, which regulates chloride flux upon GABAergic transmission. These findings suggest that the bv-associated Srrm4 mutation mainly involves post-synaptic GABAergic transmission in the central nervous system, which may be associated with the anxiety phenotype in bv/bv mice.
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Affiliation(s)
- Yuka Shirakawa
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Heng Li
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Yuki Inoue
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Hitomi Izumi
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Yoshimi Kaga
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Yu-ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
| | - Masumi Inagaki
- Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4–1-1 Ogawa Higashi, Kodaira, Tokyo 187–8553, Japan
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Vitale C, Natali G, Cerullo MS, Floss T, Michetti C, Grasselli G, Benfenati F. The homeostatic effects of the RE-1 silencing transcription factor on cortical networks are altered under ictogenic conditions in the mouse. Acta Physiol (Oxf) 2024; 240:e14146. [PMID: 38606882 DOI: 10.1111/apha.14146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/22/2024] [Accepted: 04/02/2024] [Indexed: 04/13/2024]
Abstract
AIM The Repressor Element-1 Silencing Transcription Factor (REST) is an epigenetic master regulator playing a crucial role in the nervous system. In early developmental stages, REST downregulation promotes neuronal differentiation and the acquisition of the neuronal phenotype. In addition, postnatal fluctuations in REST expression contribute to shaping neuronal networks and maintaining network homeostasis. Here we investigate the role of the early postnatal deletion of neuronal REST in the assembly and strength of excitatory and inhibitory synaptic connections. METHODS We investigated excitatory and inhibitory synaptic transmission by patch-clamp recordings in acute neocortical slices in a conditional knockout mouse model (RestGTi) in which Rest was deleted by delivering PHP.eB adeno-associated viruses encoding CRE recombinase under the control of the human synapsin I promoter in the lateral ventricles of P0-P1 pups. RESULTS We show that, under physiological conditions, Rest deletion increased the intrinsic excitability of principal cortical neurons in the primary visual cortex and the density and strength of excitatory synaptic connections impinging on them, without affecting inhibitory transmission. Conversely, in the presence of a pathological excitation/inhibition imbalance induced by pentylenetetrazol, Rest deletion prevented the increase in synaptic excitation and decreased seizure severity. CONCLUSION The data indicate that REST exerts distinct effects on the excitability of cortical circuits depending on whether it acts under physiological conditions or in the presence of pathologic network hyperexcitability. In the former case, REST preserves a correct excitatory/inhibitory balance in cortical circuits, while in the latter REST loses its homeostatic activity and may become pro-epileptogenic.
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Affiliation(s)
- Carmela Vitale
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Giulia Natali
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Maria Sabina Cerullo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Thomas Floss
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Neuherberg, Germany
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Giorgio Grasselli
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
- Department of Pharmacy, University of Genova, Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
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Natali G, Michetti C, Krawczun-Rygmaczewska A, Floss T, Cesca F, Benfenati F. Conditional knockout of REST/NRSF in excitatory neurons reduces seizure susceptibility to chemical kindling. Front Cell Neurosci 2023; 17:1267609. [PMID: 38034589 PMCID: PMC10687554 DOI: 10.3389/fncel.2023.1267609] [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: 07/26/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023] Open
Abstract
The repressor element-1 silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) is an epigenetic master regulator that plays a crucial role during nervous system development and maturation. REST function was originally described during development, where it determines neuronal phenotype. However, recent studies showed that REST participates in several processes in the adult brain, including neuronal plasticity and epileptogenesis. In this regard, the relationships between REST and epilepsy are still controversial and need further investigation. As forebrain excitatory neurons are the common final pathway of seizure susceptibility, we investigated the role of REST in epilepsy by inducing REST conditional knockout (REST-cKO) specifically in excitatory neurons of the hippocampus. To target the excitatory neuronal population, we cloned the calcium/calmodulin-dependent protein kinase IIα minimal promoter upstream of Cre recombinase. After assessing the specificity of the promoter's expression, the transgenes were packaged in an engineered adeno-associated virus able to cross the blood-brain and blood-cerebrospinal fluid barriers and delivered in the lateral ventricles of 2-month-old RESTflox/flox mice to characterize, after 1 month, the cognitive phenotype and the seizure propensity. We show that REST-cKO mice display lower levels of anxiety in the light-dark test with respect to control mice but have unaltered motor, social, and cognitive profiles. The evaluation of the susceptibility to epileptic seizures showed that REST-cKO mice are more resistant to pentylenetetrazole-induced kindling but not to seizures induced by a single administration of the convulsant and show higher survival rates. Overall, these data suggest that the absence of REST in forebrain excitatory neurons decreases seizure susceptibility, pointing to a pro-epileptogenic role of the transcriptional repressor under conditions of pathological excitation/inhibition imbalance.
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Affiliation(s)
- Giulia Natali
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Alicja Krawczun-Rygmaczewska
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Thomas Floss
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Neuherberg, Germany
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
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Fogarty MJ. Inhibitory Synaptic Influences on Developmental Motor Disorders. Int J Mol Sci 2023; 24:ijms24086962. [PMID: 37108127 PMCID: PMC10138861 DOI: 10.3390/ijms24086962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
During development, GABA and glycine play major trophic and synaptic roles in the establishment of the neuromotor system. In this review, we summarise the formation, function and maturation of GABAergic and glycinergic synapses within neuromotor circuits during development. We take special care to discuss the differences in limb and respiratory neuromotor control. We then investigate the influences that GABAergic and glycinergic neurotransmission has on two major developmental neuromotor disorders: Rett syndrome and spastic cerebral palsy. We present these two syndromes in order to contrast the approaches to disease mechanism and therapy. While both conditions have motor dysfunctions at their core, one condition Rett syndrome, despite having myriad symptoms, has scientists focused on the breathing abnormalities and their alleviation-to great clinical advances. By contrast, cerebral palsy remains a scientific quagmire or poor definitions, no widely adopted model and a lack of therapeutic focus. We conclude that the sheer abundance of diversity of inhibitory neurotransmitter targets should provide hope for intractable conditions, particularly those that exhibit broad spectra of dysfunction-such as spastic cerebral palsy and Rett syndrome.
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Affiliation(s)
- Matthew J Fogarty
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN 55902, USA
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Chen J, Wang H, Deng C, Fei M. SLC12A5 as a novel potential biomarker of glioblastoma multiforme. Mol Biol Rep 2023; 50:4285-4299. [PMID: 36917367 DOI: 10.1007/s11033-023-08371-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/02/2023] [Indexed: 03/16/2023]
Abstract
BACKGROUND Glioblastoma multiforme (GBM) is the most prevalent and malignant intracranial tumor with significant features of dismal prognosis and limited therapeutic solutions. Consequently, the present studies are committed to exploring potential biomarkers through bioinformatics analysis, which may serve as valuable prognostic predictors or novel therapeutic targets and provide new insights into the pathogenesis of GBM. METHODS We filtered overlapping differentially expressed genes (DEGs) based on expression profilings from three GBM microarray datasets (GSE116520, GSE4290 and GSE68848) and combined RNA sequencing data from The Cancer Genome Atlas and the Genotype-Tissue Expression databases. Hub genes were prioritized from DEGs after performing protein-protein interaction (PPI) network analysis and weighted gene co-expression network analysis (WGCNA). This was followed by survival analysis to identify potential biomarkers among hub genes. Ultimately, the distributions of gene expressions, genetic alterations, upstream regulatory mechanisms and enrichments of gene functions of the identified biomarkers were analysed on public databases. QRT-PCR, immunohistochemical staining and western blotting was also used to confirm the gene expression patterns in GBM and normal brain tissues. CCK-8 assay clarified the effects of the genes on GBM cells. RESULTS A total of 322 common DEGs were determined and nine genes were subsequently considered as hub genes by the combination of PPI network analysis and WGCNA. Only SLC12A5 had prognostic significance, which was deficient in GBM whereas especially enriched in normal neural tissues. SLC12A5 overexpression would inhibit cell proliferation of U251MG. Genetic alterations of SLC12A5 were rarely seen in GBM patients, and there was no apparent association existed between SLC12A5 expression and DNA methylation. SLC12A5 was prominently involved in ion transport, synapse and neurotransmitter. CONCLUSION SLC12A5 shows promise to function as a novel effective biomarker for GBM and deserves further systematic research.
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Affiliation(s)
- Jiakai Chen
- Department of Neurosurgery, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Handong Wang
- Department of Neurosurgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China.
| | - Chulei Deng
- Department of Neurosurgery, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, Jiangsu, China
| | - Maoxing Fei
- Department of Neurosurgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
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Rigkou A, Magyar A, Speer JM, Roussa E. TGF-β2 Regulates Transcription of the K +/Cl - Cotransporter 2 (KCC2) in Immature Neurons and Its Phosphorylation at T1007 in Differentiated Neurons. Cells 2022; 11:cells11233861. [PMID: 36497119 PMCID: PMC9739967 DOI: 10.3390/cells11233861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
KCC2 mediates extrusion of K+ and Cl- and assuresthe developmental "switch" in GABA function during neuronal maturation. However, the molecular mechanisms underlying KCC2 regulation are not fully elucidated. We investigated the impact of transforming growth factor beta 2 (TGF-β2) on KCC2 during neuronal maturation using quantitative RT-PCR, immunoblotting, immunofluorescence and chromatin immunoprecipitation in primary mouse hippocampal neurons and brain tissue from Tgf-β2-deficient mice. Inhibition of TGF-β/activin signaling downregulates Kcc2 transcript in immature neurons. In the forebrain of Tgf-β2-/- mice, expression of Kcc2, transcription factor Ap2β and KCC2 protein is downregulated. AP2β binds to Kcc2 promoter, a binding absent in Tgf-β2-/-. In hindbrain/brainstem tissue of Tgf-β2-/- mice, KCC2 phosphorylation at T1007 is increased and approximately half of pre-Bötzinger-complex neurons lack membrane KCC2 phenotypes rescued through exogenous TGF-β2. These results demonstrate that TGF-β2 regulates KCC2 transcription in immature neurons, possibly acting upstream of AP2β, and contributes to the developmental dephosphorylation of KCC2 at T1007. The present work suggests multiple and divergent roles for TGF-β2 on KCC2 during neuronal maturation and provides novel mechanistic insights for TGF-β2-mediated regulation of KCC2 gene expression, posttranslational modification and surface expression. We propose TGF-β2 as a major regulator of KCC2 with putative implications for pathophysiological conditions.
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Costa RO, Martins LF, Tahiri E, Duarte CB. Brain-derived neurotrophic factor-induced regulation of RNA metabolism in neuronal development and synaptic plasticity. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1713. [PMID: 35075821 DOI: 10.1002/wrna.1713] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
The neurotrophin brain-derived neurotrophic factor (BDNF) plays multiple roles in the nervous system, including in neuronal development, in long-term synaptic potentiation in different brain regions, and in neuronal survival. Alterations in these regulatory mechanisms account for several diseases of the nervous system. The synaptic effects of BDNF mediated by activation of tropomyosin receptor kinase B (TrkB) receptors are partly mediated by stimulation of local protein synthesis which is now considered a ubiquitous feature in both presynaptic and postsynaptic compartments of the neuron. The capacity to locally synthesize proteins is of great relevance at several neuronal developmental stages, including during neurite development, synapse formation, and stabilization. The available evidence shows that the effects of BDNF-TrkB signaling on local protein synthesis regulate the structure and function of the developing and mature synapses. While a large number of studies have illustrated a wide range of effects of BDNF on the postsynaptic proteome, a growing number of studies also point to presynaptic effects of the neurotrophin in the local regulation of the protein composition at the presynaptic level. Here, we will review the latest evidence on the role of BDNF in local protein synthesis, comparing the effects on the presynaptic and postsynaptic compartments. Additionally, we overview the relevance of BDNF-associated local protein synthesis in neuronal development and synaptic plasticity, at the presynaptic and postsynaptic compartments, and their relevance in terms of disease. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Export and Localization > RNA Localization.
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Affiliation(s)
- Rui O Costa
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Luís F Martins
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
- Molecular Neurobiology Laboratory, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Emanuel Tahiri
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Carlos B Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
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Hui KK, Chater TE, Goda Y, Tanaka M. How Staying Negative Is Good for the (Adult) Brain: Maintaining Chloride Homeostasis and the GABA-Shift in Neurological Disorders. Front Mol Neurosci 2022; 15:893111. [PMID: 35875665 PMCID: PMC9305173 DOI: 10.3389/fnmol.2022.893111] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023] Open
Abstract
Excitatory-inhibitory (E-I) imbalance has been shown to contribute to the pathogenesis of a wide range of neurodevelopmental disorders including autism spectrum disorders, epilepsy, and schizophrenia. GABA neurotransmission, the principal inhibitory signal in the mature brain, is critically coupled to proper regulation of chloride homeostasis. During brain maturation, changes in the transport of chloride ions across neuronal cell membranes act to gradually change the majority of GABA signaling from excitatory to inhibitory for neuronal activation, and dysregulation of this GABA-shift likely contributes to multiple neurodevelopmental abnormalities that are associated with circuit dysfunction. Whilst traditionally viewed as a phenomenon which occurs during brain development, recent evidence suggests that this GABA-shift may also be involved in neuropsychiatric disorders due to the "dematuration" of affected neurons. In this review, we will discuss the cell signaling and regulatory mechanisms underlying the GABA-shift phenomenon in the context of the latest findings in the field, in particular the role of chloride cotransporters NKCC1 and KCC2, and furthermore how these regulatory processes are altered in neurodevelopmental and neuropsychiatric disorders. We will also explore the interactions between GABAergic interneurons and other cell types in the developing brain that may influence the GABA-shift. Finally, with a greater understanding of how the GABA-shift is altered in pathological conditions, we will briefly outline recent progress on targeting NKCC1 and KCC2 as a therapeutic strategy against neurodevelopmental and neuropsychiatric disorders associated with improper chloride homeostasis and GABA-shift abnormalities.
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Affiliation(s)
- Kelvin K. Hui
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Thomas E. Chater
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
| | - Yukiko Goda
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Synapse Biology Unit, Okinawa Institute for Science and Technology Graduate University, Onna, Japan
| | - Motomasa Tanaka
- Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Japan
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Liedtke W. Long March Toward Safe and Effective Analgesia by Enhancing Gene Expression of Kcc2: First Steps Taken. Front Mol Neurosci 2022; 15:865600. [PMID: 35645734 PMCID: PMC9137411 DOI: 10.3389/fnmol.2022.865600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/08/2022] [Indexed: 11/15/2022] Open
Abstract
Low intraneuronal chloride in spinal cord dorsal horn pain relay neurons is critical for physiologic transmission of primary pain afferents because low intraneuronal chloride dictates whether GABA-ergic and glycin-ergic neurotransmission is inhibitory. If the neuronal chloride elevates to pathologic levels, then spinal cord primary pain relay becomes leaky and exhibits the behavioral hallmarks of pathologic pain, namely hypersensitivity and allodynia. Low chloride in spinal cord dorsal horn neurons is maintained by proper gene expression of Kcc2 and sustained physiologic function of the KCC2 chloride extruding electroneutral transporter. Peripheral nerve injury and other forms of neural injury evoke greatly diminished Kcc2 gene expression and subsequent corruption of inhibitory neurotransmission in the spinal cord dorsal horn, thus causing derailment of the gate function for pain. Here I review key discoveries that have helped us understand these fundamentals, and focus on recent insights relating to the discovery of Kcc2 gene expression enhancing compounds via compound screens in neurons. One such study characterized the kinase inhibitor, kenpaullone, more in-depth, revealing its function as a robust and long-lasting analgesic in preclinical models of nerve injury and cancer bone pain, also elucidating its mechanism of action via GSK3β inhibition, diminishing delta-catenin phosphorylation, and facilitating its nuclear transfer and subsequent enhancement of Kcc2 gene expression by de-repressing Kaiso epigenetic transcriptional regulator. Future directions re Kcc2 gene expression enhancement are discussed, namely combination with other analgesics and analgesic methods, such as spinal cord stimulation and electroacupuncture, gene therapy, and leveraging Kcc2 gene expression-enhancing nanomaterials.
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Tomita K, Yamanishi-Taira S, Igarashi K, Oogai Y, Kuwahara Y, Roudkenar MH, Roushandeh AM, Miyawaki S, Kurimasa A, Sato T. Oxytocin ameliorates KCC2 decrease induced by oral bacteria-derived LPS that affect rat primary cultured cells and PC-12 cells. Peptides 2022; 150:170734. [PMID: 34974081 DOI: 10.1016/j.peptides.2021.170734] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/01/2021] [Accepted: 12/28/2021] [Indexed: 01/01/2023]
Abstract
Inflammation, especially neuroinflammation, which is caused by stress, leads to central nervous system (CNS) dysfunction. Because lipopolysaccharides (LPSs) cause neuroinflammation, we investigated the effect of LPSs to CNS. In PC-12 cells, LPSs derived from oral bacteria reduced the expression of KCC2, a Cl- transporter. LPS derived from P. gingivalis (P. g) administered to rat primary cultured cells also reduced the KCC2 expression. However, LPSs derived from E. coli did not reduce the KCC2 expression. LPS treatment activated TLR4, IL-1β, and REST gene expressions, which led to KCC2 inactivation in PC-12 cells. The mechanism of KCC2 has been shown to play an important role in brain maturation, function (such as the GABA switch), and behavioral problems, we investigated the GABA function. We found that the GABA function was changed from inhibitory to excitatory by the LPS derived from P. g treatment. We demonstrated that the GSK3β also involved in the KCC2 reduction by LPS treatment. We show that oxytocin rescued the reduction in KCC2 expression caused by LPSs by inhibiting GSK3β signaling but vasopressin could not. Considered together, our results indicate that the LPSs from oral bacteria but not the LPS from E. coli increase the risk for brain disorders and oxytocin might be a candidate to overcome the abnormal behavior caused by brain disorders such as psychiatric disorders.
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Affiliation(s)
- Kazuo Tomita
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
| | - Sayuri Yamanishi-Taira
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; Department of Orthodontics and Dentofacial Orthopedics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kento Igarashi
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yuichi Oogai
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yoshikazu Kuwahara
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Mehryar Habibi Roudkenar
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; Burn and Regenerative Medicine Research Center, Velayat Hospital, School of Medicine, Guilan University of Medical Sciences, Parastar St., Rasht, 41887-94755, Iran
| | - Amaneh Mohammadi Roushandeh
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; Burn and Regenerative Medicine Research Center, Velayat Hospital, School of Medicine, Guilan University of Medical Sciences, Parastar St., Rasht, 41887-94755, Iran
| | - Shouichi Miyawaki
- Department of Orthodontics and Dentofacial Orthopedics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Akihiro Kurimasa
- Division of Radiation Biology and Medicine, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Tomoaki Sato
- Department of Applied Pharmacology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
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Serranilla M, Woodin MA. Striatal Chloride Dysregulation and Impaired GABAergic Signaling Due to Cation-Chloride Cotransporter Dysfunction in Huntington’s Disease. Front Cell Neurosci 2022; 15:817013. [PMID: 35095429 PMCID: PMC8795088 DOI: 10.3389/fncel.2021.817013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Intracellular chloride (Cl–) levels in mature neurons must be tightly regulated for the maintenance of fast synaptic inhibition. In the mature central nervous system (CNS), synaptic inhibition is primarily mediated by gamma-amino butyric acid (GABA), which binds to Cl– permeable GABAA receptors (GABAARs). The intracellular Cl– concentration is primarily maintained by the antagonistic actions of two cation-chloride cotransporters (CCCs): Cl–-importing Na+-K+-Cl– co-transporter-1 (NKCC1) and Cl– -exporting K+-Cl– co-transporter-2 (KCC2). In mature neurons in the healthy brain, KCC2 expression is higher than NKCC1, leading to lower levels of intracellular Cl–, and Cl– influx upon GABAAR activation. However, in neurons of the immature brain or in neurological disorders such as epilepsy and traumatic brain injury, impaired KCC2 function and/or enhanced NKCC1 expression lead to intracellular Cl– accumulation and GABA-mediated excitation. In Huntington’s disease (HD), KCC2- and NKCC1-mediated Cl–-regulation are also altered, which leads to GABA-mediated excitation and contributes to the development of cognitive and motor impairments. This review summarizes the role of Cl– (dys)regulation in the healthy and HD brain, with a focus on the basal ganglia (BG) circuitry and CCCs as potential therapeutic targets in the treatment of HD.
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Yeo M, Chen Y, Jiang C, Chen G, Wang K, Chandra S, Bortsov A, Lioudyno M, Zeng Q, Wang P, Wang Z, Busciglio J, Ji RR, Liedtke W. Repurposing cancer drugs identifies kenpaullone which ameliorates pathologic pain in preclinical models via normalization of inhibitory neurotransmission. Nat Commun 2021; 12:6208. [PMID: 34707084 PMCID: PMC8551327 DOI: 10.1038/s41467-021-26270-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Inhibitory GABA-ergic neurotransmission is fundamental for the adult vertebrate central nervous system and requires low chloride concentration in neurons, maintained by KCC2, a neuroprotective ion transporter that extrudes intracellular neuronal chloride. To identify Kcc2 gene expression‑enhancing compounds, we screened 1057 cell growth-regulating compounds in cultured primary cortical neurons. We identified kenpaullone (KP), which enhanced Kcc2/KCC2 expression and function in cultured rodent and human neurons by inhibiting GSK3ß. KP effectively reduced pathologic pain-like behavior in mouse models of nerve injury and bone cancer. In a nerve-injury pain model, KP restored Kcc2 expression and GABA-evoked chloride reversal potential in the spinal cord dorsal horn. Delta-catenin, a phosphorylation-target of GSK3ß in neurons, activated the Kcc2 promoter via KAISO transcription factor. Transient spinal over-expression of delta-catenin mimicked KP analgesia. Our findings of a newly repurposed compound and a novel, genetically-encoded mechanism that each enhance Kcc2 gene expression enable us to re-normalize disrupted inhibitory neurotransmission through genetic re-programming.
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Affiliation(s)
- Michele Yeo
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Yong Chen
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
| | - Changyu Jiang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Gang Chen
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Kaiyuan Wang
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Sharat Chandra
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Andrey Bortsov
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Maria Lioudyno
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Qian Zeng
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Peng Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
| | - Zilong Wang
- Department of Neurology, Duke University Medical Center, Durham, NC, USA
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA
| | - Jorge Busciglio
- Department of Neurobiology & Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), Center for the Neurobiology of Learning and Memory, University of California at Irvine, Irvine, CA, USA
| | - Ru-Rong Ji
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
| | - Wolfgang Liedtke
- Department of Neurology, Duke University Medical Center, Durham, NC, USA.
- Department of Anesthesiology (Center for Translational Pain Medicine), Duke University Medical Center, Durham, NC, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
- Duke Neurology Clinics for Headache, Head-Pain and Trigeminal Sensory Disorders, Duke University Medical Center, Durham, NC, USA.
- Duke Anesthesiology Clinics for Innovative Pain Therapy, Duke University Medical Center, Durham, NC, USA.
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14
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Butler-Ryan R, Wood IC. The functions of repressor element 1-silencing transcription factor in models of epileptogenesis and post-ischemia. Metab Brain Dis 2021; 36:1135-1150. [PMID: 33813634 PMCID: PMC8272694 DOI: 10.1007/s11011-021-00719-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Epilepsy is a debilitating neurological disorder characterised by recurrent seizures for which 30% of patients are refractory to current treatments. The genetic and molecular aetiologies behind epilepsy are under investigation with the goal of developing new epilepsy medications. The transcriptional repressor REST (Repressor Element 1-Silencing Transcription factor) is a focus of interest as it is consistently upregulated in epilepsy patients and following brain insult in animal models of epilepsy and ischemia. This review analyses data from different epilepsy models and discusses the contribution of REST to epileptogenesis. We propose that in healthy brains REST acts in a protective manner to homeostatically downregulate increases in excitability, to protect against seizure through downregulation of BDNF (Brain-Derived Neurotrophic Factor) and its receptor, TrkB (Tropomyosin receptor kinase B). However, in epilepsy patients and post-seizure, REST may increase to a larger degree, which allows downregulation of the glutamate receptor subunit GluR2. This leads to AMPA glutamate receptors lacking GluR2 subunits, which have increased permeability to Ca2+, causing excitotoxicity, cell death and seizure. This concept highlights therapeutic potential of REST modulation through gene therapy in epilepsy patients.
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Affiliation(s)
- Ruth Butler-Ryan
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
| | - Ian C. Wood
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
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15
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Inflammatory signaling sensitizes Piezo1 mechanotransduction in articular chondrocytes as a pathogenic feed-forward mechanism in osteoarthritis. Proc Natl Acad Sci U S A 2021; 118:2001611118. [PMID: 33758095 PMCID: PMC8020656 DOI: 10.1073/pnas.2001611118] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Osteoarthritis is a global health problem that affects load-bearing joints, causing loss of mobility and enormous healthcare costs. However, disease-modifying approaches are lacking. Here, we report a cellular mechanism of inflammatory signaling in chondrocytes, the cellular component of cartilage. We show how osteoarthritis-relevant levels of interleukin-1α reprogram articular chondrocytes so that they become more susceptible to mechanical trauma, which chondrocytes sense via Piezo1/2-mechanosensitive ion channels. We uncover that IL-1α enhances gene expression of Piezo1 in primary articular chondrocytes underlying Piezo1 enhanced function. We elucidate signaling from membrane to nucleus, including transcription factors that enhance Piezo1 expression. We also define consequences of increased expression of Piezo1, for mechanotransduction and at rest, that implicate this reprogramming mechanism in osteoarthritis pathogenesis. Osteoarthritis (OA) is a painful and debilitating condition of synovial joints without any disease-modifying therapies [A. M. Valdes, T. D. Spector, Nat. Rev. Rheumatol. 7, 23–32 (2011)]. We previously identified mechanosensitive PIEZO channels, PIEZO1 and PIEZO2, both expressed in articular cartilage, to function in chondrocyte mechanotransduction in response to injury [W. Lee et al., Proc. Natl. Acad. Sci. U.S.A. 111, E5114–E5122 (2014); W. Lee, F. Guilak, W. Liedtke, Curr. Top. Membr. 79, 263–273 (2017)]. We therefore asked whether interleukin-1–mediated inflammatory signaling, as occurs in OA, influences Piezo gene expression and channel function, thus indicative of maladaptive reprogramming that can be rationally targeted. Primary porcine chondrocyte culture and human osteoarthritic cartilage tissue were studied. We found that interleukin-1α (IL-1α) up-regulated Piezo1 in porcine chondrocytes. Piezo1 expression was significantly increased in human osteoarthritic cartilage. Increased Piezo1 expression in chondrocytes resulted in a feed-forward pathomechanism whereby increased function of Piezo1 induced excess intracellular Ca2+ at baseline and in response to mechanical deformation. Elevated resting state Ca2+ in turn rarefied the F-actin cytoskeleton and amplified mechanically induced deformation microtrauma. As intracellular substrates of this OA-related inflammatory pathomechanism, in porcine articular chondrocytes exposed to IL-1α, we discovered that enhanced Piezo1 expression depended on p38 MAP-kinase and transcription factors HNF4 and ATF2/CREBP1. CREBP1 directly bound to the proximal PIEZO1 gene promoter. Taken together, these signaling and genetic reprogramming events represent a detrimental Ca2+-driven feed-forward mechanism that can be rationally targeted to stem the progression of OA.
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Harada M, Nagai J, Kurata R, Cui X, Isagawa T, Semba H, Yoshida Y, Takeda N, Maemura K, Yonezawa T. Establishment of Novel Protein Interaction Assays between Sin3 and REST Using Surface Plasmon Resonance and Time-Resolved Fluorescence Energy Transfer. Int J Mol Sci 2021; 22:ijms22052323. [PMID: 33652591 PMCID: PMC7956749 DOI: 10.3390/ijms22052323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/12/2021] [Accepted: 02/22/2021] [Indexed: 11/16/2022] Open
Abstract
Repressor element-1 (RE-1) or neural restrictive silencer element (NRSE) bound with a zinc finger transcription repressor, RE-1 silencing transcription factor (REST, also known as neural restrictive silencer factor, NRSF) has been identified as a fundamental repressor element in many genes, including neuronal genes. Genes regulated by REST/NRSF regulate multifaceted neuronal phenotypes, and their defects in the machinery cause neuropathies, disorders of neuron activity), autism and so on. In REST repressions, the N-terminal repressor domain recruits Sin3B via its paired amphipathic helix 1 (PAH1) domain, which plays an important role as a scaffold for histone deacetylase 1 and 2. This machinery has a critical role in maintaining neuronal robustness. In this study, in order to establish protein–protein interaction assays mimicking a binding surface between Sin3B and REST, we selected important amino acids from structural information of the PAH1/REST complex and then tried to reconstitute it using recombinant short peptides derived from PAH1/REST. Initially, we validated whether biotinylated REST interacts with glutathione S-transferase (GST)-tagged PAH1 and whether another PAH1 peptide (PAH1-FLAG) competitively binds with biotinylated REST using surface plasmon resonance (SPR). We observed a direct interaction and competitive binding of two PAH1 peptides. Secondly, in order to establish a high-throughput and high-dynamic-range assay, we utilized an easily performed novel time-resolved fluorescence energy transfer (TR-FRET) assay, and closely monitored this interaction. Finally, we succeeded in establishing a novel high-quality TR-FRET assay and a novel interaction assay based on SPR.
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Affiliation(s)
- Masamitsu Harada
- Center for Therapeutic Innovation, Gene Research Center for Frontiers Life Sciences, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-14 Sakamoto, Nagasaki 852-8523, Japan; (M.H.); (J.N.)
| | - Jun Nagai
- Center for Therapeutic Innovation, Gene Research Center for Frontiers Life Sciences, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-14 Sakamoto, Nagasaki 852-8523, Japan; (M.H.); (J.N.)
| | - Riho Kurata
- Education and Research Center for Pharmaceutical Sciences, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan;
| | - Xiaofeng Cui
- School of Chemistry, Chemical Engineering and Life Sciences, School of Materials and Engineering, Wuhan University of Technology, 122 Loushi Rd, Wuhan 430070, China;
| | - Takayuki Isagawa
- Data Science Center, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan;
| | - Hiroaki Semba
- Department of Cardiovascular Medicine, The Cardiovascular Institute, Nishiazabu 3-2-19, Minato-ku, Tokyo 106-0031, Japan;
| | - Yasuhiro Yoshida
- Department of Immunology and Parasitology, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan;
| | - Norihiko Takeda
- Division of Cardiology and Metabolism, Center for Molecular Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan;
| | - Koji Maemura
- Department of Cardiovascular Medicine, Graduate School of Biomedical Sciences, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan;
| | - Tomo Yonezawa
- Center for Therapeutic Innovation, Gene Research Center for Frontiers Life Sciences, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-14 Sakamoto, Nagasaki 852-8523, Japan; (M.H.); (J.N.)
- Correspondence: or ; Tel.: +81-95-819-8525
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17
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Andrews K, Josiah SS, Zhang J. The Therapeutic Potential of Neuronal K-Cl Co-Transporter KCC2 in Huntington's Disease and Its Comorbidities. Int J Mol Sci 2020; 21:E9142. [PMID: 33266310 PMCID: PMC7730145 DOI: 10.3390/ijms21239142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/16/2020] [Accepted: 11/28/2020] [Indexed: 02/05/2023] Open
Abstract
Intracellular chloride levels in the brain are regulated primarily through the opposing effects of two cation-chloride co-transporters (CCCs), namely K+-Cl- co-transporter-2 (KCC2) and Na+-K+-Cl- co-transporter-1 (NKCC1). These CCCs are differentially expressed throughout the course of development, thereby determining the excitatory-to-inhibitory γ-aminobutyric acid (GABA) switch. GABAergic excitation (depolarisation) is important in controlling the healthy development of the nervous system; as the brain matures, GABAergic inhibition (hyperpolarisation) prevails. This developmental switch in excitability is important, as uncontrolled regulation of neuronal excitability can have implications for health. Huntington's disease (HD) is an example of a genetic disorder whereby the expression levels of KCC2 are abnormal due to mutant protein interactions. Although HD is primarily considered a motor disease, many other clinical manifestations exist; these often present in advance of any movement abnormalities. Cognitive change, in addition to sleep disorders, is prevalent in the HD population; the effect of uncontrolled KCC2 function on cognition and sleep has also been explored. Several mechanisms by which KCC2 expression is reduced have been proposed recently, thereby suggesting extensive investigation of KCC2 as a possible therapeutic target for the development of pharmacological compounds that can effectively treat HD co-morbidities. Hence, this review summarizes the role of KCC2 in the healthy and HD brain, and highlights recent advances that attest to KCC2 as a strong research and therapeutic target candidate.
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Affiliation(s)
| | | | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK; (K.A.); (S.S.J.)
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18
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Environmental regulation of the chloride transporter KCC2: switching inflammation off to switch the GABA on? Transl Psychiatry 2020; 10:349. [PMID: 33060559 PMCID: PMC7562743 DOI: 10.1038/s41398-020-01027-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/08/2020] [Accepted: 09/14/2020] [Indexed: 12/15/2022] Open
Abstract
Chloride homeostasis, the main determinant factor for the dynamic tuning of GABAergic inhibition during development, has emerged as a key element altered in a wide variety of brain disorders. Accordingly, developmental disorders such as schizophrenia, Autism Spectrum Disorder, Down syndrome, epilepsy, and tuberous sclerosis complex (TSC) have been associated with alterations in the expression of genes codifying for either of the two cotransporters involved in the excitatory-to-inhibitory GABA switch, KCC2 and NKCC1. These alterations can result from environmental insults, including prenatal stress and maternal separation which share, as common molecular denominator, the elevation of pro-inflammatory cytokines. In this review we report and systemize recent research articles indicating that different perinatal environmental perturbations affect the expression of chloride transporters, delaying the developmental switch of GABA signaling, and that inflammatory cytokines, in particular interleukin 1β, may represent a key causal factor for this phenomenon. Based on literature data, we provide therefore a unifying conceptual framework, linking environmental hits with the excitatory-to-inhibitory GABA switch in the context of brain developmental disorders.
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Fessel J. The paradox of opposite directions of gene expressions in MCI and AD suggests possible therapy to prevent progression of MCI to AD. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2020; 6:e12003. [PMID: 32258360 PMCID: PMC7111579 DOI: 10.1002/trc2.12003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/26/2019] [Indexed: 01/06/2023]
Abstract
One of the puzzling observations concerning mild cognitive impairment (MCI) and Alzheimer's disease (AD), is that many gene expressions in MCI may be in the opposite direction of those seen in AD. Several examples of this paradox are provided. The likely explanation lies in in the control mechanisms of gene transcription. These mechanisms include (1) modification of DNA and histones by methylation or acetylation, affecting the balance between the Compass group of proteins that enhances mRNA formation, and the Polycomb group that suppresses it; (2) compensation for the loss of one gene's function by another gene with overlapping functions; (3) reduced control of the entire neural RNA production; and (4) response to microRNAs (miRNA). Although data are inadequate to exclude with certainty any one of the indicated mechanisms, the available evidence favors overall reduced control of neural mRNA production, including the effect of miRNA. The switch occurs at a specific stage, somewhere between Braak 0-1 and Braak 2-3, in the progression from MCI to AD, which reduces the number of its likely causes. Two strong but related candidates are the repressor element-1 silencing transcription factor (REST), which in adult neurons impairs plasticity; and a miRNA, for example, miRNA124, that represses REST. Another possible explanation is that only those patients with MCI who will not progress to AD are the ones that have gene expressions in the opposite direction as in AD. The solution to the paradox may have pragmatic value.
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20
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Mori N. [Brain and Neuronal Aging: Aged Brain Controls via Gene Expression Fidelity and Master Regulatory Factors]. YAKUGAKU ZASSHI 2020; 140:395-404. [PMID: 32115559 DOI: 10.1248/yakushi.19-00193-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Providing plausible strategies for brain aging protection should be a critical concern for countries with large elderly populations including Japan. Age-related cognitive impairments and movement disorders, such as Alzheimer's and Parkinson's diseases, are caused by neurodegeneration that primarily initiates in the hippocampus and the midbrain substantia nigra, respectively. Neurons are postmitotic, and therefore, the accuracy of cellular metabolism should be crucial for maintaining neural functions throughout their life. Thus accuracy of protein synthesis is a critical concern in discussing mechanisms of aging. The essence of the so-called "error catastrophe theory" of aging was on the fidelity of ribosomal translation and/or aminoacylation of tRNA. There is evidence that reduced protein synthesis accuracy results in neurodegeneration. Similarly, reduced proteostasis via autophagy and proteasomes in aging is crucial for protein quality control and well documented as a risk for aging. In both neurodegeneration and protein quality controls, various proteins are involved in their regulation, but recent evidence suggests that repressor element-1 silencing transcription factor (REST) could be a master regulatory protein that is crucial for orchestrating the neural protecting events in human brain aging. REST is induced in the aged brain, and protects neurons against oxidative stress and protein toxicity. Interestingly, REST is identical with neuron-restrictive silencer factor (NRSF), the master regulator of neural development. Thus NRSF/REST play important roles in both neurogenesis and neurodegeneration. In this review, I summarize the interesting scientific crossover, and discuss the potential use of NRSF/REST as a pharmaceutical target for controlling aging, particularly in relation to brain aging.
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Affiliation(s)
- Nozomu Mori
- Department of Anatomy and Neurobiology, Nagasaki University School of Medicine
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21
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Tang BL. The Expanding Therapeutic Potential of Neuronal KCC2. Cells 2020; 9:E240. [PMID: 31963584 PMCID: PMC7016893 DOI: 10.3390/cells9010240] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/09/2020] [Accepted: 01/16/2020] [Indexed: 02/06/2023] Open
Abstract
Dysfunctions in GABAergic inhibitory neural transmission occur in neuronal injuries and neurological disorders. The potassium-chloride cotransporter 2 (KCC2, SLC12A5) is a key modulator of inhibitory GABAergic inputs in healthy adult neurons, as its chloride (Cl-) extruding activity underlies the hyperpolarizing reversal potential for GABAA receptor Cl- currents (EGABA). Manipulation of KCC2 levels or activity improve symptoms associated with epilepsy and neuropathy. Recent works have now indicated that pharmacological enhancement of KCC2 function could reactivate dormant relay circuits in an injured mouse's spinal cord, leading to functional recovery and the attenuation of neuronal abnormality and disease phenotype associated with a mouse model of Rett syndrome (RTT). KCC2 interacts with Huntingtin and is downregulated in Huntington's disease (HD), which contributed to GABAergic excitation and memory deficits in the R6/2 mouse HD model. Here, these recent advances are highlighted, which attest to KCC2's growing potential as a therapeutic target for neuropathological conditions resulting from dysfunctional inhibitory input.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore; ; Tel.: +65-6516-1040
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore
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22
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Carminati E, Buffolo F, Rocchi A, Michetti C, Cesca F, Benfenati F. Mild Inactivation of RE-1 Silencing Transcription Factor (REST) Reduces Susceptibility to Kainic Acid-Induced Seizures. Front Cell Neurosci 2020; 13:580. [PMID: 31998079 PMCID: PMC6965066 DOI: 10.3389/fncel.2019.00580] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 12/18/2019] [Indexed: 11/13/2022] Open
Abstract
RE-1 Silencing Transcription factor (REST) controls several steps in neural development by modulating the expression of a wide range of neural genes. Alterations in REST expression have been associated with the onset of epilepsy; however, whether such alterations are deleterious or represent a protective homeostatic response remains elusive. To study the impact of REST modulation on seizure propensity, we developed a tool for its negative modulation in vivo. The tool is composed of the paired-amphipathic helix 1 (PAH1) domain, a competitive inhibitor of REST activation by mSin3, fused to the light-oxygen-voltage sensing 2 (LOV2) domain of Avena sativa phototropin 1, a molecular switch to alternatively hide or expose the PAH1 inhibitor. We employed the C450A and I539E light-independent AsLOV2 variants to mimic the closed (inactive) and open (active) states of LOV2-PAH1, respectively. Recombinant AAV1/2 viral particles (rAAVs) allowed LOV2-PAH1 expression in HEK293T cells and primary neurons, and efficiently transduced hippocampal neurons in vivo. mRNA expression analysis revealed an increased expression of several neuronal genes in the hippocampi of mice expressing the open probe. AAV-transduced mice received a single dose of kainic acid (KA), a treatment known to induce a transient increase of REST levels in the hippocampus. Remarkably, mice expressing the active variant displayed a reduced number of KA-induced seizures, which were less severe compared to mice carrying the inactive probe. These data support the validity of our tool to modulate REST activity in vivo and the potential impact of REST modulation on epileptogenesis.
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Affiliation(s)
- Emanuele Carminati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Federica Buffolo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Anna Rocchi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
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23
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Poiana G, Gioia R, Sineri S, Cardarelli S, Lupo G, Cacci E. Transcriptional regulation of adult neural stem/progenitor cells: tales from the subventricular zone. Neural Regen Res 2020; 15:1773-1783. [PMID: 32246617 PMCID: PMC7513981 DOI: 10.4103/1673-5374.280301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In rodents, well characterized neurogenic niches of the adult brain, such as the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampus, support the maintenance of neural/stem progenitor cells (NSPCs) and the production of new neurons throughout the lifespan. The adult neurogenic process is dependent on the intrinsic gene expression signatures of NSPCs that make them competent for self-renewal and neuronal differentiation. At the same time, it is receptive to regulation by various extracellular signals that allow the modulation of neuronal production and integration into brain circuitries by various physiological stimuli. A drawback of this plasticity is the sensitivity of adult neurogenesis to alterations of the niche environment that can occur due to aging, injury or disease. At the core of the molecular mechanisms regulating neurogenesis, several transcription factors have been identified that maintain NSPC identity and mediate NSPC response to extrinsic cues. Here, we focus on REST, Egr1 and Dbx2 and their roles in adult neurogenesis, especially in the subventricular zone. We review recent work from our and other laboratories implicating these transcription factors in the control of NSPC proliferation and differentiation and in the response of NSPCs to extrinsic influences from the niche. We also discuss how their altered regulation may affect the neurogenic process in the aged and in the diseased brain. Finally, we highlight key open questions that need to be addressed to foster our understanding of the transcriptional mechanisms controlling adult neurogenesis.
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Affiliation(s)
- Giancarlo Poiana
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Roberta Gioia
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Serena Sineri
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Silvia Cardarelli
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Giuseppe Lupo
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Emanuele Cacci
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
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24
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Tang X, Drotar J, Li K, Clairmont CD, Brumm AS, Sullins AJ, Wu H, Liu XS, Wang J, Gray NS, Sur M, Jaenisch R. Pharmacological enhancement of KCC2 gene expression exerts therapeutic effects on human Rett syndrome neurons and Mecp2 mutant mice. Sci Transl Med 2019; 11:eaau0164. [PMID: 31366578 PMCID: PMC8140401 DOI: 10.1126/scitranslmed.aau0164] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 04/14/2019] [Accepted: 07/12/2019] [Indexed: 12/14/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the methyl CpG binding protein 2 (MECP2) gene. There are currently no approved treatments for RTT. The expression of K+/Cl- cotransporter 2 (KCC2), a neuron-specific protein, has been found to be reduced in human RTT neurons and in RTT mouse models, suggesting that KCC2 might play a role in the pathophysiology of RTT. To develop neuron-based high-throughput screening (HTS) assays to identify chemical compounds that enhance the expression of the KCC2 gene, we report the generation of a robust high-throughput drug screening platform that allows for the rapid assessment of KCC2 gene expression in genome-edited human reporter neurons. From an unbiased screen of more than 900 small-molecule chemicals, we have identified a group of compounds that enhance KCC2 expression termed KCC2 expression-enhancing compounds (KEECs). The identified KEECs include U.S. Food and Drug Administration-approved drugs that are inhibitors of the fms-like tyrosine kinase 3 (FLT3) or glycogen synthase kinase 3β (GSK3β) pathways and activators of the sirtuin 1 (SIRT1) and transient receptor potential cation channel subfamily V member 1 (TRPV1) pathways. Treatment with hit compounds increased KCC2 expression in human wild-type (WT) and isogenic MECP2 mutant RTT neurons, and rescued electrophysiological and morphological abnormalities of RTT neurons. Injection of KEEC KW-2449 or piperine in Mecp2 mutant mice ameliorated disease-associated respiratory and locomotion phenotypes. The small-molecule compounds described in our study may have therapeutic effects not only in RTT but also in other neurological disorders involving dysregulation of KCC2.
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Affiliation(s)
- Xin Tang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Jesse Drotar
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Keji Li
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | - Austin J Sullins
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hao Wu
- Fulcrum Therapeutics, Cambridge, MA 02139, USA
| | | | - Jinhua Wang
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Nathanael S Gray
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Mriganka Sur
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
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25
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Nakano Y, Wiechert S, Bánfi B. Overlapping Activities of Two Neuronal Splicing Factors Switch the GABA Effect from Excitatory to Inhibitory by Regulating REST. Cell Rep 2019; 27:860-871.e8. [PMID: 30995482 PMCID: PMC6556397 DOI: 10.1016/j.celrep.2019.03.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 01/22/2019] [Accepted: 03/18/2019] [Indexed: 11/23/2022] Open
Abstract
A truncating mutation in the mouse Srrm4 gene, which encodes a neuronal splicing factor, causes alternative splicing defects selectively in the ear. The mechanism by which splicing is preserved in the brain of these mice is not known. Here, we show that SRRM3 limits the Srrm4 mutation-associated defects to the ear and that, in cortical neurons, overlapping SRRM3-SRRM4 activity regulates the development of interneuronal inhibition. In vitro, SRRM3 and SRRM4 regulate the same splicing events, but a mutation in mouse Srrm3 causes tremors and mild defects in neuronal alternative splicing, demonstrating unique SRRM3 roles in vivo. Mice harboring mutations in both Srrm3 and Srrm4 die neonatally and exhibit severe splicing defects. In these mice, splicing alterations prevent inactivation of the gene repressor REST, which maintains immature excitatory GABAergic neurotransmission by repressing K-Cl cotransporter 2. Thus, our data reveal that SRRM3 and SRRM4 act redundantly to regulate GABAergic neurotransmission by inactivating REST.
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Affiliation(s)
- Yoko Nakano
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Susan Wiechert
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Botond Bánfi
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Otolaryngology-Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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26
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Lee-Hotta S, Uchiyama Y, Kametaka S. Role of the BDNF-TrkB pathway in KCC2 regulation and rehabilitation following neuronal injury: A mini review. Neurochem Int 2019; 128:32-38. [PMID: 30986502 DOI: 10.1016/j.neuint.2019.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/04/2019] [Accepted: 04/08/2019] [Indexed: 02/08/2023]
Abstract
In most mature neurons, low levels of intracellular Cl- concentrations ([Cl-]i) are maintained by channels and transporters, particularly the K+-Cl- cotransporter 2 (KCC2), which is the only Cl- extruder in most neurons. Recent studies have implicated KCC2 expression in the molecular mechanisms underlying neuronal disorders, such as spasticity, epilepsy and neuropathic pain. Alterations in KCC2 expression have been associated with brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin-related kinase B (TrkB). The present review summarizes recent progress regarding the roles of Cl- regulators in immature and mature neurons. Moreover, we focus on the role of KCC2 regulation via the BDNF-TrkB pathway in spinal cord injury and rehabilitation, as prior studies have shown that the BDNF-TrkB pathway can affect both the pathological development and functional amelioration of spinal cord injuries. Evidence suggests that rehabilitation using active exercise and mechanical stimulation can attenuate spasticity and neuropathic pain in animal models, likely due to the upregulation of KCC2 expression via the BDNF-TrkB pathway. Moreover, research suggests that such rehabilitation efforts may recover KCC2 expression without the use of exogenous BDNF.
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Affiliation(s)
- Sachiko Lee-Hotta
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
| | - Yasushi Uchiyama
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
| | - Satoshi Kametaka
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, 1-1-20, Daiko-minami Higashi-ku, Nagoya-shi, Aichi, 461-8673, Japan.
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27
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Mampay M, Sheridan GK. REST: An epigenetic regulator of neuronal stress responses in the young and ageing brain. Front Neuroendocrinol 2019; 53:100744. [PMID: 31004616 DOI: 10.1016/j.yfrne.2019.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/03/2019] [Accepted: 04/11/2019] [Indexed: 12/27/2022]
Abstract
The transcriptional repressor REST (Repressor Element-1 Silencing Transcription factor) is a key modulator of the neuronal epigenome and targets genes involved in neuronal differentiation, axonal growth, vesicular transport, ion channel conductance and synaptic plasticity. Whilst its gene expression-modifying properties have been examined extensively in neuronal development, REST's response towards stress-induced neuronal insults has only recently been explored. Overall, REST appears to be an ideal candidate to fine-tune neuronal gene expression following different forms of cellular, neuropathological, psychological and physical stressors. Upregulation of REST is reportedly protective against premature neural stem cell depletion, neuronal hyperexcitability, oxidative stress, neuroendocrine system dysfunction and neuropathology. In contrast, neuronal REST activation has also been linked to neuronal dysfunction and neurodegeneration. Here, we highlight key findings and discrepancies surrounding our current understanding of REST's function in neuronal adaptation to stress and explore its potential role in neuronal stress resilience in the young and ageing brain.
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Affiliation(s)
- Myrthe Mampay
- Neuroimmunology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK
| | - Graham K Sheridan
- Neuroimmunology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK.
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28
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Côme E, Heubl M, Schwartz EJ, Poncer JC, Lévi S. Reciprocal Regulation of KCC2 Trafficking and Synaptic Activity. Front Cell Neurosci 2019; 13:48. [PMID: 30842727 PMCID: PMC6391895 DOI: 10.3389/fncel.2019.00048] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/01/2019] [Indexed: 01/05/2023] Open
Abstract
The main inhibitory neurotransmitter receptors in the adult central nervous system (CNS) are type A γ-aminobutyric acid receptors (GABAARs) and glycine receptors (GlyRs). Synaptic responses mediated by GlyR and GABAAR display a hyperpolarizing shift during development. This shift relies mainly on the developmental up-regulation of the K+-Cl- co-transporter KCC2 responsible for the extrusion of Cl-. In mature neurons, altered KCC2 function-mainly through increased endocytosis-leads to the re-emergence of depolarizing GABAergic and glycinergic signaling, which promotes hyperexcitability and pathological activities. Identifying signaling pathways and molecular partners that control KCC2 surface stability thus represents a key step in the development of novel therapeutic strategies. Here, we present our current knowledge on the cellular and molecular mechanisms governing the plasma membrane turnover rate of the transporter under resting conditions and in response to synaptic activity. We also discuss the notion that KCC2 lateral diffusion is one of the first parameters modulating the transporter membrane stability, allowing for rapid adaptation of Cl- transport to changes in neuronal activity.
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Affiliation(s)
- Etienne Côme
- INSERM UMR-S 1270, Paris, France.,Sorbonne Université, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Martin Heubl
- INSERM UMR-S 1270, Paris, France.,Sorbonne Université, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Eric J Schwartz
- INSERM UMR-S 1270, Paris, France.,Sorbonne Université, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Jean Christophe Poncer
- INSERM UMR-S 1270, Paris, France.,Sorbonne Université, Paris, France.,Institut du Fer à Moulin, Paris, France
| | - Sabine Lévi
- INSERM UMR-S 1270, Paris, France.,Sorbonne Université, Paris, France.,Institut du Fer à Moulin, Paris, France
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29
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Hsu YT, Chang YG, Chern Y. Insights into GABA Aergic system alteration in Huntington's disease. Open Biol 2018; 8:rsob.180165. [PMID: 30518638 PMCID: PMC6303784 DOI: 10.1098/rsob.180165] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 10/30/2018] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disease that is characterized by a triad of motor, psychiatric and cognitive impairments. There is still no effective therapy to delay or halt the disease progress. The striatum and cortex are two particularly affected brain regions that exhibit dense reciprocal excitatory glutamate and inhibitory gamma-amino butyric acid (GABA) connections. Imbalance between excitatory and inhibitory signalling is known to greatly affect motor and cognitive processes. Emerging evidence supports the hypothesis that disrupted GABAergic circuits underlie HD pathogenesis. In the present review, we focused on the multiple defects recently found in the GABAergic inhibitory system, including altered GABA level and synthesis, abnormal subunit composition and distribution of GABAA receptors and aberrant GABAA receptor-mediated signalling. In particular, the important role of cation–chloride cotransporters (i.e. NKCC1 and KCC2) is discussed. Recent studies also suggest that neuroinflammation contributes significantly to the abnormal GABAergic inhibition in HD. Thus, GABAA receptors and cation–chloride cotransporters are potential therapeutic targets for HD. Given the limited availability of therapeutic treatments for HD, a better understanding of GABAergic dysfunction in HD could provide novel therapeutic opportunities.
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Affiliation(s)
- Yi-Ting Hsu
- PhD Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan, Republic of China.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan, Republic of China
| | - Ya-Gin Chang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, Republic of China.,Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan, Republic of China
| | - Yijuang Chern
- PhD Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan, Republic of China .,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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30
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Corradini I, Focchi E, Rasile M, Morini R, Desiato G, Tomasoni R, Lizier M, Ghirardini E, Fesce R, Morone D, Barajon I, Antonucci F, Pozzi D, Matteoli M. Maternal Immune Activation Delays Excitatory-to-Inhibitory Gamma-Aminobutyric Acid Switch in Offspring. Biol Psychiatry 2018; 83:680-691. [PMID: 29146047 DOI: 10.1016/j.biopsych.2017.09.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/03/2017] [Accepted: 09/11/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND The association between maternal infection and neurodevelopmental defects in progeny is well established, although the biological mechanisms and the pathogenic trajectories involved have not been defined. METHODS Pregnant dams were injected intraperitoneally at gestational day 9 with polyinosinic:polycytidylic acid. Neuronal development was assessed by means of electrophysiological, optical, and biochemical analyses. RESULTS Prenatal exposure to polyinosinic:polycytidylic acid causes an imbalanced expression of the Na+-K+-2Cl- cotransporter 1 and the K+-Cl- cotransporter 2 (KCC2). This results in delayed gamma-aminobutyric acid switch and higher susceptibility to seizures, which endures up to adulthood. Chromatin immunoprecipitation experiments reveal increased binding of the repressor factor RE1-silencing transcription (also known as neuron-restrictive silencer factor) to position 509 of the KCC2 promoter that leads to downregulation of KCC2 transcription in prenatally exposed offspring. Interleukin-1 receptor type I knockout mice, which display braked immune response and no brain cytokine elevation upon maternal immune activation, do not display KCC2/Na+-K+-2Cl- cotransporter 1 imbalance when implanted in a wild-type dam and prenatally exposed. Notably, pretreatment of pregnant dams with magnesium sulfate is sufficient to prevent the early inflammatory state and the delay in excitatory-to-inhibitory switch associated to maternal immune activation. CONCLUSIONS We provide evidence that maternal immune activation hits a key neurodevelopmental process, the excitatory-to-inhibitory gamma-aminobutyric acid switch; defects in this switch have been unequivocally linked to diseases such as autism spectrum disorder or epilepsy. These data open the avenue for a safe pharmacological treatment that may prevent the neurodevelopmental defects caused by prenatal immune activation in a specific pregnancy time window.
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Affiliation(s)
- Irene Corradini
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Institute of Neuroscience - National Research Council, Milan, Italy
| | - Elisa Focchi
- Institute of Neuroscience - National Research Council, Milan, Italy; Department of Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Marco Rasile
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Hunimed University, Rozzano, Italy
| | - Raffaella Morini
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy
| | - Genni Desiato
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; University of Milano-Bicocca, Milan, Italy
| | - Romana Tomasoni
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy
| | - Michela Lizier
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Institute for Genetic and Biomedical Research - National Research Council, Milan, Italy
| | - Elsa Ghirardini
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Department of Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Riccardo Fesce
- Hunimed University, Rozzano, Italy; Neuroscience Center, Dipartimento di Scienze Teoriche e Applicate, Insubria University, Busto Arsizio, Italy
| | - Diego Morone
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy
| | | | - Flavia Antonucci
- Department of Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Davide Pozzi
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Hunimed University, Rozzano, Italy
| | - Michela Matteoli
- Istituto di Ricovero e Cura a Carattere Scientifico Humanitas, Rozzano, Italy; Institute of Neuroscience - National Research Council, Milan, Italy.
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31
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Pozzi D, Menna E, Canzi A, Desiato G, Mantovani C, Matteoli M. The Communication Between the Immune and Nervous Systems: The Role of IL-1β in Synaptopathies. Front Mol Neurosci 2018; 11:111. [PMID: 29674955 PMCID: PMC5895746 DOI: 10.3389/fnmol.2018.00111] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/20/2018] [Indexed: 12/14/2022] Open
Abstract
In the last 15 years, groundbreaking genetic progress has underlined a convergence onto coherent synaptic pathways for most psychiatric and neurodevelopmental disorders, which are now collectively called “synaptopathies.” However, the modest size of inheritance detected so far indicates a multifactorial etiology for these disorders, underlining the key contribution of environmental effects to them. Inflammation is known to influence the risk and/or severity of a variety of synaptopathies. In particular, pro-inflammatory cytokines, produced and released in the brain by activated astrocytes and microglia, may play a pivotal role in these pathologies. Although the link between immune system activation and defects in cognitive processes is nowadays clearly established, the knowledge of the molecular mechanisms by which inflammatory mediators specifically hit synaptic components implicated in synaptopathies is still in its infancy. This review summarizes recent evidence showing that the pro-inflammatory cytokine interleukin-1β (IL-1β) specifically targets synaptopathy molecular substrate, leading to memory defects and pathological processes. In particular, we describe three specific pathways through which IL-1β affects (1) synaptic maintenance/dendritic complexity, (2) spine morphology, and (3) the excitatory/inhibitory balance. We coin the term immune synaptopathies to identify this class of diseases.
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Affiliation(s)
- Davide Pozzi
- Department of Biomedical Sciences, Humanitas University, Rozzano, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Elisabetta Menna
- Humanitas Clinical and Research Center, Rozzano, Italy.,Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Milan, Italy
| | - Alice Canzi
- Department of Biomedical Sciences, Humanitas University, Rozzano, Italy
| | - Genni Desiato
- Humanitas Clinical and Research Center, Rozzano, Italy.,School of Medicine and Surgery, University of Milan-Bicocca, Milan, Italy
| | | | - Michela Matteoli
- Humanitas Clinical and Research Center, Rozzano, Italy.,Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, Milan, Italy
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32
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Hwang JY, Zukin RS. REST, a master transcriptional regulator in neurodegenerative disease. Curr Opin Neurobiol 2018; 48:193-200. [PMID: 29351877 DOI: 10.1016/j.conb.2017.12.008] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 12/04/2017] [Accepted: 12/17/2017] [Indexed: 12/19/2022]
Abstract
The restrictive element-1 silencing transcription factor)/NRSF (neuron-restrictive silencing factor (NRSF) is a transcriptional repressor which acts via epigenetic remodeling to silence target genes. Emerging evidence indicates that REST is a master transcriptional regulator of neuron-specific genes not only in neurogenesis and neuronal differentiation, but also in differentiated neurons during the critical period in postnatal brain development, where it plays a role in fine-tuning of genes involved in synaptic plasticity, and in normal aging, where it promotes neuroprotection by repressing genes involved in oxidative stress and β-amyloid toxicity. This review focuses on recent findings that dysregulation of REST and REST-dependent epigenetic remodeling provide a central mechanism critical to the progressive neurodegeneration associated with neurologic disorders and diseases including global ischemia, stroke, epilepsy, Alzheimer's and Huntington's disease.
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Affiliation(s)
- Jee-Yeon Hwang
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Room 610, Albert Einstein College of Medicine, 1300 Morris Park Avenue, New York, NY 10461, USA
| | - R Suzanne Zukin
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Room 610, Albert Einstein College of Medicine, 1300 Morris Park Avenue, New York, NY 10461, USA.
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33
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Kitayama T. The Role of K +-Cl --Cotransporter-2 in Neuropathic Pain. Neurochem Res 2018; 43:110-115. [PMID: 28677029 DOI: 10.1007/s11064-017-2344-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/09/2017] [Accepted: 06/26/2017] [Indexed: 01/21/2023]
Abstract
The pain sensory system normally functions under a fine balance between excitation and inhibition. When this balance is perturbed for some reason, it leads to neuropathic pain. There is accumulating evidence that attributes this pain generation to specific dysfunctions of the inhibitory system in the spinal cord. One possible mechanism leading to the induction of these dysfunctions is the down-regulation of K+-Cl--cotransporter-2 (KCC2) expression. In fact, various neuropathic pain models indicate a decrease of KCC2 expression in the spinal cord. The alteration of KCC2 expression affects GABAergic and glycinergic neurotransmissions, because KCC2 is a potassium-chloride exporter and serves to maintain intracellular chloride concentration. When there is a low level of KCC2 expression, GABAergic and glycinergic neurotransmissions transform from inhibitory signals to excitatory signals. In this review, the hypothesis that an alteration of KCC2 expression has a crucial influence on the initiation/development or maintenance of neuropathic pain is discussed. In addition, it is suggested that the alteration of inhibitory signals is dependent on the time after peripheral nerve injury.
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Affiliation(s)
- Tomoya Kitayama
- Department of Pharmacy, School of Pharmacy and Pharmaceutical Science, Mukogawa Women's University, 11-68 Koshien-Kyubanmachi, Nishinomiya, Hyogo, 663-8179, Japan.
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34
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Abstract
K+-Cl- co-transporter 2 (KCC2/SLC12A5) is a neuronal specific cation chloride co-transporter which is active under isotonic conditions, and thus a key regulator of intracellular Cl- levels. It also has an ion transporter-independent structural role in modulating the maturation and regulation of excitatory glutamatergic synapses. KCC2 levels are developmentally regulated, and a postnatal upregulation of KCC2 generates a low intracellular chloride concentration that allows the neurotransmitters γ-aminobutyric acid (GABA) and glycine to exert inhibitory neurotransmission through its Cl- permeating channel. Functional expression of KCC2 at the neuronal cell surface is necessary for its activity, and impairment in KCC2 cell surface transport and/or internalization may underlie a range of neuropathological conditions. Although recent advances have shed light on a range of cellular mechanisms regulating KCC2 activity, little is known about its membrane trafficking itinerary and regulatory proteins. In this review, known membrane trafficking signals, pathways and mechanisms pertaining to KCC2's functional surface expression are discussed.
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Affiliation(s)
- Bor Luen Tang
- a Department of Biochemistry, Yong Loo Lin School of Medicine , National University Health System , Singapore.,b NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore
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35
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Moore YE, Kelley MR, Brandon NJ, Deeb TZ, Moss SJ. Seizing Control of KCC2: A New Therapeutic Target for Epilepsy. Trends Neurosci 2017; 40:555-571. [PMID: 28803659 DOI: 10.1016/j.tins.2017.06.008] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 11/17/2022]
Abstract
Deficits in GABAergic inhibition result in the abnormal neuronal activation and synchronization that underlies seizures. However, the molecular mechanisms responsible for transforming a normal brain into an epileptic one remain largely unknown. Hyperpolarizing inhibition mediated by type A GABA (GABAA) receptors is dependent on chloride extrusion by the neuron-specific type 2K+-Cl- cotransporter (KCC2). Loss-of-function mutations in KCC2 are a known cause of infantile epilepsy in humans and KCC2 dysfunction is present in patients with both idiopathic and acquired epilepsy. Here we discuss the growing evidence that KCC2 dysfunction has a central role in the development and severity of the epilepsies.
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Affiliation(s)
- Yvonne E Moore
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Matt R Kelley
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Nicholas J Brandon
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA; AstraZeneca Neuroscience, Innovative Medicines and Early Development Biotech Unit, R&D Boston, Waltham, MA 024515, USA
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA
| | - Stephen J Moss
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA 02111, USA.
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36
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Hsu YT, Chang YG, Chang CP, Siew JJ, Chen HM, Tsai CH, Chern Y. Altered behavioral responses to gamma-aminobutyric acid pharmacological agents in a mouse model of Huntington's disease. Mov Disord 2017; 32:1600-1609. [PMID: 28782830 DOI: 10.1002/mds.27107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 06/21/2017] [Accepted: 06/23/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Disruptions in gamma-aminobutyric (GABA) acid signaling are believed to be involved in Huntington's disease pathogenesis, but the regulation of GABAergic signaling remains elusive. Here we evaluated GABAergic signaling by examining the function of GABAergic drugs in Huntington's disease and the expression of GABAergic molecules using mouse models and human brain tissues from Huntington's disease. METHODS We treated wild-type and R6/2 mice (a transgenic Huntington's disease mouse model) acutely with vehicle, diazepam, or gaboxadol (drugs that selectively target synaptic or extrasynaptic GABAA receptors) and monitored their locomotor activity. The expression levels of GABAA receptors and a major neuron-specific chloride extruder (potassium-chloride cotransporter-2) were analyzed by real-time quantitative polymerase chain reaction, Western blot, and immunocytochemistry. RESULTS The R6/2 mice were less sensitive to the sedative effects of both drugs, suggesting reduced function of GABAA receptors. Consistently, the expression levels of α1/α2 and δ subunits were lower in the cortex and striatum of R6/2 mice. Similar results were also found in 2 other mouse models of Huntington's disease and in Huntington's disease patients. Moreover, the interaction and expression levels of potassium-chloride cotransporter-2 and its activator (brain-type creatine kinase) were decreased in Huntington's disease neurons. These findings collectively suggest impaired chloride homeostasis, which further dampens GABAA receptor-mediated inhibitory signaling in Huntington's disease brains. CONCLUSIONS The dysregulated GABAergic responses and altered expression levels of GABAA receptors and potassium-chloride cotransporter-2 in Huntington's disease mice appear to be authentic and may contribute to the clinical manifestations of Huntington's disease patients. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Yi-Ting Hsu
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan
| | - Ya-Gin Chang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Ching-Pang Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jian-Jing Siew
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hui-Mei Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chon-Haw Tsai
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Department of Neurology, China Medical University Hospital, Taichung, Taiwan
| | - Yijuang Chern
- Ph.D. Program for Translational Medicine, China Medical University and Academia Sinica, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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Martin D, Grapin-Botton A. The Importance of REST for Development and Function of Beta Cells. Front Cell Dev Biol 2017; 5:12. [PMID: 28286748 PMCID: PMC5323410 DOI: 10.3389/fcell.2017.00012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/07/2017] [Indexed: 01/10/2023] Open
Abstract
Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes that are crucial for both neuronal and pancreatic endocrine function, through the recruitment of multiple transcriptional and epigenetic co-regulators. REST targets include genes encoding transcription factors, proteins involved in exocytosis, synaptic transmission or ion channeling, and non-coding RNAs. REST is expressed in the progenitors of both neurons and beta cells during development, but it is down-regulated as the cells differentiate. Although REST mutations and deregulation have yet to be connected to diabetes in humans, REST activation during both development and in adult beta cells leads to diabetes in mice.
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Affiliation(s)
- David Martin
- Service of Cardiology, Centre Hospitalier Universitaire Vaudois (CHUV) Lausanne, Switzerland
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Bode C, Richter F, Spröte C, Brigadski T, Bauer A, Fietz S, Fritschy JM, Richter A. Altered postnatal maturation of striatal GABAergic interneurons in a phenotypic animal model of dystonia. Exp Neurol 2017; 287:44-53. [PMID: 27780732 DOI: 10.1016/j.expneurol.2016.10.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/30/2016] [Accepted: 10/21/2016] [Indexed: 01/05/2023]
Abstract
GABAergic disinhibition has been suggested to play a critical role in the pathophysiology of several basal ganglia disorders, including dystonia, a common movement disorder. Previous studies have shown a deficit of striatal GABAergic interneurons (IN) in the dtsz mutant hamster, one of the few phenotypic animal models of dystonia. However, mechanisms underlying this deficit are largely unknown. In the present study, we investigated the migration and maturation of striatal IN during postnatal development (18days of age) and at age of highest severity of dystonia (33days of age) in this hamster model. In line with previous findings, the density of GAD67-positive IN and the level of parvalbumin mRNA, a marker for fast spiking GABAergic IN, were lower in the dtsz mutant than in control hamsters. However, an unaltered density of Nkx2.1 labeled cells and Nkx2.1 mRNA level suggested that the migration of GABAergic IN into the striatum was not retarded. Therefore, different factors that indicate maturation of GABAergic IN were determined. While mRNA of the KCC2 cation/chloride transporters and the cytosolic carboanhydrase VII, used as markers for the so called GABA switch, as well as BDNF were unaltered, we found a reduced number of IN expressing the alpha1 subunit of the GABAA-receptor (37.5%) in dtsz hamsters at an age of 33days, but not after spontaneous remission of dystonia at an age of 90days. Since IN shift expression from alpha2 to alpha1 subunits during postnatal maturation, this result together with a decreased parvalbumin mRNA expression suggest a delayed maturation of striatal GABAergic IN in this animal model, which might underlie abnormal neuronal activity and striatal plasticity.
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Affiliation(s)
- Christoph Bode
- Institute of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Franziska Richter
- Institute of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany.
| | - Christine Spröte
- Institute of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Tanja Brigadski
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany; Center of Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany
| | - Anne Bauer
- Institute of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Simone Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich 8057, Switzerland
| | - Angelika Richter
- Institute of Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany.
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Abstract
Autism spectrum disorder (ASD) is a group of complex neurodevelopmental conditions characterized by deficits in social communication and by repetitive and stereotypic patterns of behaviors, with no pharmacological treatments available to treat these core symptoms. Oxytocin is a neuropeptide that powerfully regulates mammalian social behavior and has been shown to exert pro-social effects when administered intranasally to healthy human subjects. In the last decade, there has been a significant interest in using oxytocin to treat social behavior deficits in ASD. However, little attention has been paid to whether the oxytocin system is perturbed in subgroups of individuals with ASD and whether these individuals are likely to benefit more from an oxytocin treatment. This oversight may in part be due to the enormous heterogeneity of ASD and the lack of methods to carefully probe the OXT system in human subjects. Animal models for ASD are valuable tools to clarify the implication of the oxytocin system in ASD and can help determine whether perturbation in this system should be considered in future clinical studies as stratifying biomarkers to inform targeted treatments in subgroups of individuals with ASD. In this chapter, we review the literature on genetic- and environmental-based animal models for ASD, in which perturbations in the oxytocin system and/or the effect of oxytocin administration on the ASD-associated phenotype have been investigated.
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Sedmak G, Jovanov-Milošević N, Puskarjov M, Ulamec M, Krušlin B, Kaila K, Judaš M. Developmental Expression Patterns of KCC2 and Functionally Associated Molecules in the Human Brain. Cereb Cortex 2016; 26:4574-4589. [PMID: 26428952 DOI: 10.1093/cercor/bhv218] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Work on rodents demonstrated that steep upregulation of KCC2, a neuron-specific Cl- extruder of cation-chloride cotransporter (CCC) family, commences in supraspinal structures at around birth, leading to establishment of hyperpolarizing GABAergic responses. We describe spatiotemporal expression profiles of the entire CCC family in human brain. KCC2 mRNA was observed already at 10th postconceptional week (PCW) in amygdala, cerebellum, and thalamus. KCC2-immunoreactive (KCC2-ir) neurons were abundant in subplate at 18 PCW. By 25 PCW, numerous subplate and cortical plate neurons became KCC2-ir. The mRNA expression profiles of α- and β-isoforms of Na-K ATPase, which fuels cation-chloride cotransport, as well of tropomyosin receptor kinase B (TrkB), which promotes developmental upregulation of KCC2, were consistent with data from studies on rodents about their interactions with KCC2. Thus, in human brain, expression of KCC2 and its functionally associated proteins begins in early fetal period. Our work facilitates translation of results on CCC functions from animal studies to human and refutes the view that poor efficacy of anticonvulsants in the term human neonate is attributable to the lack of KCC2. We propose that perinatally low threshold for activation of Ca2+-dependent protease calpain renders neonates susceptible to downregulation of KCC2 by traumatic events, such as perinatal hypoxia ischemia.
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Affiliation(s)
| | | | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
| | - Monika Ulamec
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Božo Krušlin
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
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Kanju P, Chen Y, Lee W, Yeo M, Lee SH, Romac J, Shahid R, Fan P, Gooden DM, Simon SA, Spasojevic I, Mook RA, Liddle RA, Guilak F, Liedtke WB. Small molecule dual-inhibitors of TRPV4 and TRPA1 for attenuation of inflammation and pain. Sci Rep 2016; 6:26894. [PMID: 27247148 PMCID: PMC4887995 DOI: 10.1038/srep26894] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 05/10/2016] [Indexed: 12/20/2022] Open
Abstract
TRPV4 ion channels represent osmo-mechano-TRP channels with pleiotropic function and wide-spread expression. One of the critical functions of TRPV4 in this spectrum is its involvement in pain and inflammation. However, few small-molecule inhibitors of TRPV4 are available. Here we developed TRPV4-inhibitory molecules based on modifications of a known TRPV4-selective tool-compound, GSK205. We not only increased TRPV4-inhibitory potency, but surprisingly also generated two compounds that potently co-inhibit TRPA1, known to function as chemical sensor of noxious and irritant signaling. We demonstrate TRPV4 inhibition by these compounds in primary cells with known TRPV4 expression - articular chondrocytes and astrocytes. Importantly, our novel compounds attenuate pain behavior in a trigeminal irritant pain model that is known to rely on TRPV4 and TRPA1. Furthermore, our novel dual-channel blocker inhibited inflammation and pain-associated behavior in a model of acute pancreatitis – known to also rely on TRPV4 and TRPA1. Our results illustrate proof of a novel concept inherent in our prototype compounds of a drug that targets two functionally-related TRP channels, and thus can be used to combat isoforms of pain and inflammation in-vivo that involve more than one TRP channel. This approach could provide a novel paradigm for treating other relevant health conditions.
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Affiliation(s)
| | - Yong Chen
- Dept of Neurology, Duke University, Durham NC USA
| | - Whasil Lee
- Dept of Neurology, Duke University, Durham NC USA
| | - Michele Yeo
- Dept of Neurology, Duke University, Durham NC USA
| | - Suk Hee Lee
- Dept of Neurology, Duke University, Durham NC USA
| | - Joelle Romac
- Dept of Medicine, Duke University, Durham NC USA
| | - Rafiq Shahid
- Dept of Medicine, Duke University, Durham NC USA
| | - Ping Fan
- Dept of Medicine, Duke University, Durham NC USA
| | | | | | | | - Robert A Mook
- Dept of Medicine, Duke University, Durham NC USA.,Dept of Chemistry, Duke University, Durham NC USA
| | | | - Farshid Guilak
- Dept of Orthopedic Surgery, Washington University in St Louis and Shriners Hospitals for Children, St Louis MO USA
| | - Wolfgang B Liedtke
- Dept of Neurology, Duke University, Durham NC USA.,Dept of Neurobiology, Duke University, Durham NC USA.,Dept of Anesthesiology, Duke University, Durham NC USA.,Neurology Clinics for Headache, Head-Pain and Trigeminal Sensory Disorders, Duke University, Durham NC USA
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KCC2 rescues functional deficits in human neurons derived from patients with Rett syndrome. Proc Natl Acad Sci U S A 2016; 113:751-6. [PMID: 26733678 DOI: 10.1073/pnas.1524013113] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Rett syndrome is a severe form of autism spectrum disorder, mainly caused by mutations of a single gene methyl CpG binding protein 2 (MeCP2) on the X chromosome. Patients with Rett syndrome exhibit a period of normal development followed by regression of brain function and the emergence of autistic behaviors. However, the mechanism behind the delayed onset of symptoms is largely unknown. Here we demonstrate that neuron-specific K(+)-Cl(-) cotransporter2 (KCC2) is a critical downstream gene target of MeCP2. We found that human neurons differentiated from induced pluripotent stem cells from patients with Rett syndrome showed a significant deficit in KCC2 expression and consequently a delayed GABA functional switch from excitation to inhibition. Interestingly, overexpression of KCC2 in MeCP2-deficient neurons rescued GABA functional deficits, suggesting an important role of KCC2 in Rett syndrome. We further identified that RE1-silencing transcriptional factor, REST, a neuronal gene repressor, mediates the MeCP2 regulation of KCC2. Because KCC2 is a slow onset molecule with expression level reaching maximum later in development, the functional deficit of KCC2 may offer an explanation for the delayed onset of Rett symptoms. Our studies suggest that restoring KCC2 function in Rett neurons may lead to a potential treatment for Rett syndrome.
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Frederikse PH, Kasinathan C. KCC2 expression supersedes NKCC1 in mature fiber cells in mouse and rabbit lenses. Mol Vis 2015; 21:1142-50. [PMID: 26539026 PMCID: PMC4605749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/11/2015] [Indexed: 11/16/2022] Open
Abstract
PURPOSE Na-K-Cl cotransporter 1 (NKCC1) and K-Cl cotransporter 2 (KCC2) have fundamental roles in neuron differentiation that are integrated with gamma-aminobutyric acid (GABA) and glutamate receptors, GABA synthesized by GAD25/65/67 encoded by GAD1/GAD2 genes, and GABA transporters (GATs). Cells in the eye lens express at least 13 GABA receptor subunits, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl D-aspartate (NMDA) glutamate receptors, GAD1/GAD2, GAT1-4 and vGAT, and NKCC1. NKCC1:KCC2 ratios determine the switch in GABA actions from trophic/growth promoting early in development to their classic inhibitory roles in adult neurons. Lens epithelial cells cover the anterior surface and differentiate to elongated fiber cells in the lens interior with comparable morphology and sub-cellular structures as neurons. NKCC1 is expressed before KCC2 in neuron development and increases cell chloride, which stimulates differentiation and process formation. Subsequently, KCC2 increases and extrudes cell chloride linked with maturation. KCC2 has an additional structural moonlighting role interacting with F-actin scaffolding in dendritic spine morphogenesis. We examined KCC2 versus NKCC1 spatial expression in relation to fiber cell developmental status within the lens. METHODS Immunofluorescence and immunoblots were used to detect expression in mouse and rabbit lenses. RESULTS NKCC1 was restricted to peripheral elongating lens fiber cells in young adult mouse and rabbit lenses. Lens KCC2 expression included the major KCC2b neuronal isoform and was detected in interior fiber cells with decreased NKCC1 expression and localized at the membranes. Lens expression of RE-1 silencing transcription factor (REST) regulated KCC2 is consistent with GAD1 and GAD2, several GABA and glutamate receptor subunits, miR-124, and other REST-regulated genes expressed in lenses. CONCLUSIONS NKCC1 in peripheral elongating fiber cells is superseded by KCC2 expression in interior mature fiber cells that also express >20 additional integral GABA biology genes, AMPA/NMDA glutamate receptors, and an array of accessory proteins that together underlie morphogenesis in neurons. The present findings provide further evidence that this fundamental neuronal regulation is extensively conserved in lens and identify additional parallels in the morphogenetic programs that underlie lens fiber cell and neuronal differentiation and contribute to the development of visual acuity.
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MESH Headings
- Animals
- Cell Differentiation
- Cell Lineage/physiology
- Epithelial Cells/cytology
- Epithelial Cells/metabolism
- Gene Expression Regulation, Developmental
- Glutamate Decarboxylase/genetics
- Glutamate Decarboxylase/metabolism
- Lens, Crystalline/cytology
- Lens, Crystalline/growth & development
- Lens, Crystalline/metabolism
- Mice
- Mice, Inbred C57BL
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Neurons/cytology
- Neurons/metabolism
- Rabbits
- Receptors, AMPA/genetics
- Receptors, AMPA/metabolism
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Signal Transduction
- Solute Carrier Family 12, Member 2/genetics
- Solute Carrier Family 12, Member 2/metabolism
- Symporters/genetics
- Symporters/metabolism
- gamma-Aminobutyric Acid/metabolism
- K Cl- Cotransporters
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Sp3/REST/HDAC1/HDAC2 Complex Represses and Sp1/HIF-1/p300 Complex Activates ncx1 Gene Transcription, in Brain Ischemia and in Ischemic Brain Preconditioning, by Epigenetic Mechanism. J Neurosci 2015; 35:7332-48. [PMID: 25972164 DOI: 10.1523/jneurosci.2174-14.2015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Na(+)-Ca(2+) exchanger 1 (NCX1) is reduced in stroke by the RE1-silencing transcription factor (REST), whereas it is increased in ischemic brain preconditioning (PC) by hypoxia-inducible factor 1 (HIF-1). Because ncx1 brain promoter (ncx1-Br) has five putative consensus sequences, named Sp1A-E, for the specificity protein (Sp) family of transcription factors (Sp1-4), we investigated the role of this family in regulating ncx1 transcription in rat cortical neurons. Here we found that Sp1 is a transcriptional activator, whereas Sp3 is a transcriptional repressor of ncx1, and that both bind ncx1-Br in a sequence-specific manner, modulating ncx1 transcription through the Sp1 sites C-E. Furthermore, by transient middle cerebral artery occlusion (tMCAO) in rats, the transcriptional repressors Sp3 and REST colocalized with the two histone-deacetylases (HDACs) HDAC1 and HDAC2 on the ncx1-Br, with a consequent hypoacetylation. Contrarily, in PC+tMCAO the transcriptional activators Sp1 and HIF-1 colocalized with histone acetyltransferase p300 on ncx1-Br with a consequent hyperacetylation. In addition, in neurons silenced with siRNA of NCX1 and subjected to oxygen and glucose deprivation (OGD) (3 h) plus reoxygenation (RX) (24 h), the neuroprotection of Class I HDAC inhibitor MS-275 was counteracted, whereas in neurons overexpressing NCX1 and subjected to ischemic preconditioning (PC+OGD/RX), the neurotoxic effect of p300 inhibitor C646 was prevented. Collectively, these results demonstrate that NCX1 expression is regulated by the Sp3/REST/HDAC1/HDAC2 complex in tMCAO and by the Sp1/HIF-1/p300 complex in PC+tMCAO and that epigenetic intervention, by modulating the acetylation of ncx1-Br, may be a strategy for the development of innovative therapeutic intervention in stroke.
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The Transcription Repressor REST in Adult Neurons: Physiology, Pathology, and Diseases. eNeuro 2015; 2:eN-REV-0010-15. [PMID: 26465007 PMCID: PMC4596026 DOI: 10.1523/eneuro.0010-15.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 06/11/2015] [Accepted: 06/18/2015] [Indexed: 12/21/2022] Open
Abstract
REST [RE1-silencing transcription factor (also called neuron-restrictive silencer factor)] is known to repress thousands of possible target genes, many of which are neuron specific. To date, REST repression has been investigated mostly in stem cells and differentiating neurons. Current evidence demonstrates its importance in adult neurons as well. Low levels of REST, which are acquired during differentiation, govern the expression of specific neuronal phenotypes. REST-dependent genes encode important targets, including transcription factors, transmitter release proteins, voltage-dependent and receptor channels, and signaling proteins. Additional neuronal properties depend on miRNAs expressed reciprocally to REST and on specific splicing factors. In adult neurons, REST levels are not always low. Increases occur during aging in healthy humans. Moreover, extensive evidence demonstrates that prolonged stimulation with various agents induces REST increases, which are associated with the repression of neuron-specific genes with appropriate, intermediate REST binding affinity. Whether neuronal increases in REST are protective or detrimental remains a subject of debate. Examples of CA1 hippocampal neuron protection upon depolarization, and of neurodegeneration upon glutamate treatment and hypoxia have been reported. REST participation in psychiatric and neurological diseases has been shown, especially in Alzheimer’s disease and Huntington’s disease, as well as epilepsy. Distinct, complex roles of the repressor in these different diseases have emerged. In conclusion, REST is certainly very important in a large number of conditions. We suggest that the conflicting results reported for the role of REST in physiology, pathology, and disease depend on its complex, direct, and indirect actions on many gene targets and on the diverse approaches used during the investigations.
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Synergy between Piezo1 and Piezo2 channels confers high-strain mechanosensitivity to articular cartilage. Proc Natl Acad Sci U S A 2014; 111:E5114-22. [PMID: 25385580 DOI: 10.1073/pnas.1414298111] [Citation(s) in RCA: 277] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Diarthrodial joints are essential for load bearing and locomotion. Physiologically, articular cartilage sustains millions of cycles of mechanical loading. Chondrocytes, the cells in cartilage, regulate their metabolic activities in response to mechanical loading. Pathological mechanical stress can lead to maladaptive cellular responses and subsequent cartilage degeneration. We sought to deconstruct chondrocyte mechanotransduction by identifying mechanosensitive ion channels functioning at injurious levels of strain. We detected robust expression of the recently identified mechanosensitive channels, PIEZO1 and PIEZO2. Combined directed expression of Piezo1 and -2 sustained potentiated mechanically induced Ca(2+) signals and electrical currents compared with single-Piezo expression. In primary articular chondrocytes, mechanically evoked Ca(2+) transients produced by atomic force microscopy were inhibited by GsMTx4, a PIEZO-blocking peptide, and by Piezo1- or Piezo2-specific siRNA. We complemented the cellular approach with an explant-cartilage injury model. GsMTx4 reduced chondrocyte death after mechanical injury, suggesting a possible therapy for reducing cartilage injury and posttraumatic osteoarthritis by attenuating Piezo-mediated cartilage mechanotransduction of injurious strains.
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Kaila K, Price TJ, Payne JA, Puskarjov M, Voipio J. Cation-chloride cotransporters in neuronal development, plasticity and disease. Nat Rev Neurosci 2014; 15:637-54. [PMID: 25234263 DOI: 10.1038/nrn3819] [Citation(s) in RCA: 504] [Impact Index Per Article: 50.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Electrical activity in neurons requires a seamless functional coupling between plasmalemmal ion channels and ion transporters. Although ion channels have been studied intensively for several decades, research on ion transporters is in its infancy. In recent years, it has become evident that one family of ion transporters, cation-chloride cotransporters (CCCs), and in particular K(+)-Cl(-) cotransporter 2 (KCC2), have seminal roles in shaping GABAergic signalling and neuronal connectivity. Studying the functions of these transporters may lead to major paradigm shifts in our understanding of the mechanisms underlying brain development and plasticity in health and disease.
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Affiliation(s)
- Kai Kaila
- 1] Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland
| | - Theodore J Price
- University of Texas at Dallas, School of Behavior and Brain Sciences, Dallas, Texas 75093, USA
| | - John A Payne
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California 95616, USA
| | - Martin Puskarjov
- 1] Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland
| | - Juha Voipio
- Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
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Deisz RA, Wierschke S, Schneider UC, Dehnicke C. Effects of VU0240551, a novel KCC2 antagonist, and DIDS on chloride homeostasis of neocortical neurons from rats and humans. Neuroscience 2014; 277:831-41. [PMID: 25086309 DOI: 10.1016/j.neuroscience.2014.07.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 11/24/2022]
Abstract
The normal function of GABAA receptor-mediated inhibition is governed by several factors, including release of GABA, subunit composition and density of the receptors and in particular by the appropriate ionic gradient. In the human epileptogenic neocortex an impaired chloride (Cl(-)) gradient has been proposed, due to decreases of potassium-coupled chloride transport (KCC2) and voltage-gated Cl(-) channels (ClC). Regarding sodium- and potassium-coupled Cl(-) transport (NKCC1) both up- and downregulations have been proposed. We investigated changes of Cl(-) homeostasis of human and rat neocortical neurons (layer 2/3) with intracellular recordings and iontophoretic Cl(-) loading employing selective compounds. After cessation of iontophoresis, the IPSPA amplitudes of rat neurons recovered with a time constant (τrec) of 6.5s (n=21). In human neurons, τrec averaged 17.8s (n=36; 23 resections). Application of the novel KCC2 blocker VU0240551 (1 μM) caused in rat neurons a reversible prolongation of τrec from 5.7 to 8.1s (n=11), corresponding to a VU0240551-sensitive Cl(-) transport rate (1/Δτrec) of 0.0504s(-1). In human neurons, τrec increased on application of 1μM VU0240551, on average from 15.1 to 20.3s (n=17). The human neurons comprised two subgroups with different τrec when segregated according to a border given by the mean+2s.d. of rat neurons. In one group, τrec averaged 8.7s (n=6) and reversibly increased to 14.6s in the presence of 1μM VU0240551, corresponding to a Cl(-) transport rate of 0.0504s(-1). The other group had an average τrec of 18.5s which increased in the presence of 1μM VU0240551 to 23.3s (n=11), indicating a much smaller rate (0.0151s(-1)). Addition of DIDS, a presumed blocker of anion exchanger (AE), increased the τrec of rat neurons from 7.5 to 8.8s (n=6) corresponding to a DIDS-sensitive rate of 0.0185s(-1). In human neurons, DIDS increased τrec from 23.3 to 50.7s (n=7), corresponding to a DIDS-sensitive rate of 0.0200s(-1). These data suggest a greatly reduced KCC2-mediated transport rate in most of the human neurons. The two subgroups observed in human tissue indicate a considerable variability of Cl(-) transport within a given tissue from almost normal to greatly impeded, predominated by a decline of KCC2 whereas AE is unaltered.
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Affiliation(s)
- R A Deisz
- Charité Universitätsmedizin Berlin, Centre for Anatomy, Institute for Cell Biology and Neurobiology, Berlin, Germany.
| | - S Wierschke
- Charité Universitätsmedizin Berlin, Centre for Anatomy, Institute for Cell Biology and Neurobiology, Berlin, Germany
| | - U C Schneider
- Charité Universitätsmedizin Berlin, Department of Neurosurgery, Berlin, Germany
| | - C Dehnicke
- Epilepsie-Zentrum Berlin-Brandenburg, Evangelisches Krankenhaus Königin Elisabeth Herzberge, Berlin, Germany
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50
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Jantzie LL, Getsy PM, Firl DJ, Wilson CG, Miller RH, Robinson S. Erythropoietin attenuates loss of potassium chloride co-transporters following prenatal brain injury. Mol Cell Neurosci 2014; 61:152-62. [PMID: 24983520 PMCID: PMC4134983 DOI: 10.1016/j.mcn.2014.06.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 04/17/2014] [Accepted: 06/09/2014] [Indexed: 11/22/2022] Open
Abstract
Therapeutic agents that restore the inhibitory actions of γ-amino butyric acid (GABA) by modulating intracellular chloride concentrations will provide novel avenues to treat stroke, chronic pain, epilepsy, autism, and neurodegenerative and cognitive disorders. During development, upregulation of the potassium-chloride co-transporter KCC2, and the resultant switch from excitatory to inhibitory responses to GABA guide the formation of essential inhibitory circuits. Importantly, maturation of inhibitory mechanisms is also central to the development of excitatory circuits and proper balance between excitatory and inhibitory networks in the developing brain. Loss of KCC2 expression occurs in postmortem samples from human preterm infant brains with white matter lesions. Here we show that late gestation brain injury in a rat model of extreme prematurity impairs the developmental upregulation of potassium chloride co-transporters during a critical postnatal period of circuit maturation in CA3 hippocampus by inducing a sustained loss of oligomeric KCC2 via a calpain-dependent mechanism. Further, administration of erythropoietin (EPO) in a clinically relevant postnatal dosing regimen following the prenatal injury protects the developing brain by reducing calpain activity, restoring oligomeric KCC2 expression and attenuating KCC2 fragmentation, thus providing the first report of a safe therapy to address deficits in KCC2 expression. Together, these data indicate it is possible to reverse abnormalities in KCC2 expression during the postnatal period, and potentially reverse deficits in inhibitory circuit formation central to cognitive impairment and epileptogenesis.
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Affiliation(s)
- L L Jantzie
- Department of Neurology, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA; Department of Neurosurgery, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA
| | - P M Getsy
- Department of Pediatrics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA
| | - D J Firl
- Department of Neurology, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA; Department of Neurosurgery, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA
| | - C G Wilson
- Department of Pediatrics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA
| | - R H Miller
- Department of Neurosciences, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA
| | - S Robinson
- Department of Neurology, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA; Department of Neurosurgery, Boston Children's Hospital & Harvard Medical School, 300 Longwood Avenue, Boston MA 02115, USA.
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