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Matsumoto D, Ushio S, Wada Y, Noda Y, Esumi S, Izushi Y, Kitamura Y, Sendo T. Bumetanide prevents diazepam-modified anxiety-like behavior in lipopolysaccharide-treated mice. Eur J Pharmacol 2021; 904:174195. [PMID: 34004209 DOI: 10.1016/j.ejphar.2021.174195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 10/21/2022]
Abstract
Benzodiazepine receptor agonists are widely prescribed therapeutic agents that alter gamma-aminobutyric acid (GABA)A receptor activity and have anxiolytic effects. Post-operative use of benzodiazepines is a risk factor of delirium. Inflammatory conditions alter the anxiolytic effects of benzodiazepine. We investigated the effect of diazepam, a typical benzodiazepine anxiolytic, on changes in the emotional behavior of mice in a hole-board test after lipopolysaccharide (LPS) treatment. Diazepam dose-dependently increased the number of head-dips at doses that did not alter locomotor activity; however, diazepam dose-dependently significantly decreased the number of head-dips at doses that did not alter locomotor activity in LPS-treated mice. Flumazenil, a benzodiazepine receptor antagonist, normalized the decrease in head-dipping behavior caused by diazepam treatment in normal and LPS-treated mice. The decrease of the head-dipping effect caused by diazepam was attenuated by minocycline in LPS-treated mice. We further found that the decrease in head-dipping behavior caused by diazepam was blocked by bumetanide, a Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) antagonist, in LPS-treated mice. These findings suggest that diazepam induces the anxiety-like behavior under inflammation conditions, and may cause the GABAA receptor dysfunction associated with the chloride plasticity mediated by NKCC1, which contributes to benzodiazepine-induced delirium after surgery.
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Affiliation(s)
- Daiki Matsumoto
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Soichiro Ushio
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Yudai Wada
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Yukiko Noda
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Satoru Esumi
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Yasuhisa Izushi
- Department of Pharmacotherapy, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama, 703-8516, Japan
| | - Yoshihisa Kitamura
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan; Department of Pharmacotherapy, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama, 703-8516, Japan.
| | - Toshiaki Sendo
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan; Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
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Kawano S, Itoh K, Ishihara Y. Maternal intake of docosahexaenoic acid decreased febrile seizure sensitivity by increasing estrogen synthesis in offspring. Epilepsy Behav 2021; 121:108038. [PMID: 34052639 DOI: 10.1016/j.yebeh.2021.108038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 10/21/2022]
Abstract
Febrile seizures, which are convulsion in children, are caused by an abrupt increase in body temperature. They are sometimes recurrent, and the more seizures are triggered, the higher the risk of epilepsy and psychiatric disorders increase after growing up. Prevention of febrile seizure is considered to be one of the effective countermeasures in protecting the future health of children; however, pharmacological prevention in the developmental stage is not realistic from the health aspects of the offspring. Docosahexaenoic acid (DHA) is an important nutrient especially during pregnancy and childhood and is reported to suppress several types of epilepsy. The purpose of this study was to examine the effect of DHA intake during pregnancy and infancy on febrile seizures in mice. We used a heat chamber for febrile seizure induction in offspring at the age of from 10 to 11 days old. Intake of DHA during pregnancy and infancy significantly increased the amount of DHA in the brain of offspring. Although DHA had no effect on seizure severity, DHA significantly prolonged the seizure latency and increased body temperature at which the first seizure occurred, indicating that maternal DHA intake decreases febrile seizure sensitivity. Brain estrogen levels significantly increased by DHA intake and administration of an inhibitor for cytochrome P450 aromatase, which is a rate-limiting enzyme for estrogen synthesis, clearly decreased seizure latency and body temperature at which the first seizure occurred. Taken together, DHA could reduce susceptibility to febrile seizures owing to increases in brain estrogen contents. DHA intake during pregnancy and infancy is of significance in protecting infant from seizures as well as conserving health after growth.
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Affiliation(s)
- Shinji Kawano
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8521, Japan
| | - Kouichi Itoh
- Laboratory for Pharmacotherapy and Experimental Neurology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
| | - Yasuhiro Ishihara
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8521, Japan.
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Sergeeva EG, Rosenberg PA, Benowitz LI. Non-Cell-Autonomous Regulation of Optic Nerve Regeneration by Amacrine Cells. Front Cell Neurosci 2021; 15:666798. [PMID: 33935656 PMCID: PMC8085350 DOI: 10.3389/fncel.2021.666798] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/19/2021] [Indexed: 11/13/2022] Open
Abstract
Visual information is conveyed from the eye to the brain through the axons of retinal ganglion cells (RGCs) that course through the optic nerve and synapse onto neurons in multiple subcortical visual relay areas. RGCs cannot regenerate their axons once they are damaged, similar to most mature neurons in the central nervous system (CNS), and soon undergo cell death. These phenomena of neurodegeneration and regenerative failure are widely viewed as being determined by cell-intrinsic mechanisms within RGCs or to be influenced by the extracellular environment, including glial or inflammatory cells. However, a new concept is emerging that the death or survival of RGCs and their ability to regenerate axons are also influenced by the complex circuitry of the retina and that the activation of a multicellular signaling cascade involving changes in inhibitory interneurons - the amacrine cells (AC) - contributes to the fate of RGCs. Here, we review our current understanding of the role that interneurons play in cell survival and axon regeneration after optic nerve injury.
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Affiliation(s)
- Elena G. Sergeeva
- Department of Neurology, Boston Children’s Hospital, Boston, MA, United States
- Kirby Center for Neuroscience, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Paul A. Rosenberg
- Department of Neurology, Boston Children’s Hospital, Boston, MA, United States
- Kirby Center for Neuroscience, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Larry I. Benowitz
- Kirby Center for Neuroscience, Boston Children’s Hospital, Boston, MA, United States
- Laboratories for Neuroscience Research in Neurosurgery, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurosurgery, Boston Children’s Hospital, Boston, MA, United States
- Department of Neurosurgery, Harvard Medical School, Boston, MA, United States
- Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
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Doi A, Miyazaki T, Mihara T, Ikeda M, Niikura R, Andoh T, Goto T. CLP290 promotes the sedative effects of midazolam in neonatal rats in a KCC2-dependent manner: A laboratory study in rats. PLoS One 2021; 16:e0248113. [PMID: 33711029 PMCID: PMC7954344 DOI: 10.1371/journal.pone.0248113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/22/2021] [Indexed: 11/25/2022] Open
Abstract
Immature neurons dominantly express the Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) rather than the K+-Cl- cotransporter isoform 2 (KCC2). The intracellular chloride ion concentration ([Cl-]i) is higher in immature neurons than in mature neurons; therefore, γ-aminobutyric acid type A (GABAA) receptor activation in immature neurons does not cause chloride ion influx and subsequent hyperpolarization. In our previous work, we found that midazolam, benzodiazepine receptor agonist, causes less sedation in neonatal rats compared to adult rats and that NKCC1 blockade by bumetanide enhances the midazolam-induced sedation in neonatal, but not in adult, rats. These results suggest that GABA receptor activation requires the predominance of KCC2 over NKCC1 to exert sedative effects. In this study, we focused on CLP290, a novel KCC2-selective activator, and found that midazolam administration at 20 mg/kg after oral CLP290 intake significantly prolonged the righting reflex latency even in neonatal rats at postnatal day 7. By contrast, CLP290 alone did not exert sedative effects. Immunohistochemistry showed that midazolam combined with CLP290 decreased the number of phosphorylated cAMP response element-binding protein-positive cells in the cerebral cortex, suggesting that CLP290 reverted the inhibitory effect of midazolam. Moreover, the sedative effect of combined CLP290 and midazolam treatment was inhibited by the administration of the KCC2-selective inhibitor VU0463271, suggesting indirectly that the sedation-promoting effect of CLP290 was mediated by KCC2 activation. To our knowledge, this study is the first report showing the sedation-promoting effect of CLP290 in neonates and providing behavioral and histological evidence that CLP290 reverted the sedative effect of GABAergic drugs through the activation of KCC2. Our data suggest that the clinical application of CLP290 may provide a breakthrough in terms of midazolam-resistant sedation.
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Affiliation(s)
- Akiko Doi
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Mihara
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Maiko Ikeda
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryo Niikura
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomio Andoh
- Department of Anesthesiology, Mizonokuchi Hospital, Teikyo University School of Medicine, Kawasaki, Japan
| | - Takahisa Goto
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Smirnova EY, Sinyak DS, Chizhov AV, Zaitsev AV. Age-Dependent Generation of Epileptiform
Activity
in the 4-Aminopyridine Model with Slices of the Rat Entorhinal Cortex. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Virtanen MA, Uvarov P, Mavrovic M, Poncer JC, Kaila K. The Multifaceted Roles of KCC2 in Cortical Development. Trends Neurosci 2021; 44:378-392. [PMID: 33640193 DOI: 10.1016/j.tins.2021.01.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
KCC2, best known as the neuron-specific chloride-extruder that sets the strength and polarity of GABAergic currents during neuronal maturation, is a multifunctional molecule that can regulate cytoskeletal dynamics via its C-terminal domain (CTD). We describe the molecular and cellular mechanisms involved in the multiple functions of KCC2 and its splice variants, ranging from developmental apoptosis and the control of early network events to the formation and plasticity of cortical dendritic spines. The versatility of KCC2 actions at the cellular and subcellular levels is also evident in mature neurons during plasticity, disease, and aging. Thus, KCC2 has emerged as one of the most important molecules that shape the overall neuronal phenotype.
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Affiliation(s)
- Mari A Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Martina Mavrovic
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland; Department of Molecular Medicine, University of Oslo, 0372 Oslo, Norway
| | - Jean Christophe Poncer
- INSERM, UMRS 1270, 75005 Paris, France; Sorbonne Université, 75005 Paris, France; Institut du Fer à Moulin, 75005 Paris, France
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland.
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Intricacies of GABA A Receptor Function: The Critical Role of the β3 Subunit in Norm and Pathology. Int J Mol Sci 2021; 22:ijms22031457. [PMID: 33535681 PMCID: PMC7867123 DOI: 10.3390/ijms22031457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Neuronal intracellular chloride ([Cl−]i) is a key determinant in γ-aminobutyric acid type A (GABA)ergic signaling. γ-Aminobutyric acid type A receptors (GABAARs) mediate both inhibitory and excitatory neurotransmission, as the passive fluxes of Cl− and HCO3− via pores can be reversed by changes in the transmembrane concentration gradient of Cl−. The cation–chloride co-transporters (CCCs) are the primary systems for maintaining [Cl−]i homeostasis. However, despite extensive electrophysiological data obtained in vitro that are supported by a wide range of molecular biological studies on the expression patterns and properties of CCCs, the presence of ontogenetic changes in [Cl−]i—along with the consequent shift in GABA reversal potential—remain a subject of debate. Recent studies showed that the β3 subunit possesses properties of the P-type ATPase that participates in the ATP-consuming movement of Cl− via the receptor. Moreover, row studies have demonstrated that the β3 subunit is a key player in GABAAR performance and in the appearance of serious neurological disorders. In this review, we discuss the properties and driving forces of CCCs and Cl−, HCO3−ATPase in the maintenance of [Cl−]i homeostasis after changes in upcoming GABAAR function. Moreover, we discuss the contribution of the β3 subunit in the manifestation of epilepsy, autism, and other syndromes.
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58
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Gazzo G, Melchior M, Caussaint A, Gieré C, Lelièvre V, Poisbeau P. Overexpression of chloride importer NKCC1 contributes to the sensory-affective and sociability phenotype of rats following neonatal maternal separation. Brain Behav Immun 2021; 92:193-202. [PMID: 33316378 DOI: 10.1016/j.bbi.2020.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Early life stress is known to affect the development of the nervous system and its function at a later age. It increases the risk to develop psychiatric disorders as well as chronic pain and its associated affective comorbidities across the lifespan. GABAergic inhibition is important for the regulation of central function and related behaviors, including nociception, anxiety or social interactions, and requires low intracellular chloride levels. Of particular interest, the oxytocinergic (OTergic) system exerts potent anxiolytic, analgesic and pro-social properties and is known to be involved in the regulation of chloride homeostasis and to be impaired following early life stress. METHODS We used behavioral measures to evaluate anxiety, social interactions and pain responses in a rat model of neonatal maternal separation (NMS). Using quantitative PCR, we investigated whether NMS was associated with alterations in the expression of chloride transporters in the cerebrum and spinal cord. Finally, we evaluated the contribution of OTergic signaling and neuro-inflammatory processes in the observed phenotype. RESULTS NMS animals displayed a long-lasting upregulation of chloride importer Na-K-Cl cotransporter type 1 (NKCC1) expression in the cerebrum and spinal cord. Neonatal administration of the NKCC1 inhibitor bumetanide or oxytocin successfully normalized the anxiety-like symptoms and the lack of social preference observed in NMS animals. Phenotypic alterations were associated with a pro-inflammatory state which could contribute to NKCC1 upregulation. CONCLUSIONS This work suggests that an impaired chloride homeostasis, linked to oxytocin signaling dysfunction and to neuro-inflammatory processes, could contribute to the sensori-affective phenotype following NMS.
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Affiliation(s)
- Géraldine Gazzo
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France
| | - Meggane Melchior
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France
| | - Andréa Caussaint
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France
| | - Clémence Gieré
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France
| | - Vincent Lelièvre
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France
| | - Pierrick Poisbeau
- Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 67000 Strasbourg, France.
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59
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Lombardi A, Jedlicka P, Luhmann HJ, Kilb W. Coincident glutamatergic depolarizations enhance GABAA receptor-dependent Cl- influx in mature and suppress Cl- efflux in immature neurons. PLoS Comput Biol 2021; 17:e1008573. [PMID: 33465082 PMCID: PMC7845986 DOI: 10.1371/journal.pcbi.1008573] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/29/2021] [Accepted: 11/30/2020] [Indexed: 11/19/2022] Open
Abstract
The impact of GABAergic transmission on neuronal excitability depends on the Cl--gradient across membranes. However, the Cl--fluxes through GABAA receptors alter the intracellular Cl- concentration ([Cl-]i) and in turn attenuate GABAergic responses, a process termed ionic plasticity. Recently it has been shown that coincident glutamatergic inputs significantly affect ionic plasticity. Yet how the [Cl-]i changes depend on the properties of glutamatergic inputs and their spatiotemporal relation to GABAergic stimuli is unknown. To investigate this issue, we used compartmental biophysical models of Cl- dynamics simulating either a simple ball-and-stick topology or a reconstructed CA3 neuron. These computational experiments demonstrated that glutamatergic co-stimulation enhances GABA receptor-mediated Cl- influx at low and attenuates or reverses the Cl- efflux at high initial [Cl-]i. The size of glutamatergic influence on GABAergic Cl--fluxes depends on the conductance, decay kinetics, and localization of glutamatergic inputs. Surprisingly, the glutamatergic shift in GABAergic Cl--fluxes is invariant to latencies between GABAergic and glutamatergic inputs over a substantial interval. In agreement with experimental data, simulations in a reconstructed CA3 pyramidal neuron with physiological patterns of correlated activity revealed that coincident glutamatergic synaptic inputs contribute significantly to the activity-dependent [Cl-]i changes. Whereas the influence of spatial correlation between distributed glutamatergic and GABAergic inputs was negligible, their temporal correlation played a significant role. In summary, our results demonstrate that glutamatergic co-stimulation had a substantial impact on ionic plasticity of GABAergic responses, enhancing the attenuation of GABAergic inhibition in the mature nervous systems, but suppressing GABAergic [Cl-]i changes in the immature brain. Therefore, glutamatergic shift in GABAergic Cl--fluxes should be considered as a relevant factor of short-term plasticity. Information processing in the brain requires that excitation and inhibition are balanced. The main inhibitory neurotransmitter in the brain is gamma-amino-butyric acid (GABA). GABA actions depend on the Cl--gradient, but activation of ionotropic GABA receptors causes Cl--fluxes and thus reduces GABAergic inhibition. Here, we investigated how a coincident membrane depolarization by excitatory glutamatergic synapses influences GABA-induced Cl--fluxes using a biophysical compartmental model of Cl- dynamics, simulating either simple or realistic neuron topologies. We demonstrate that glutamatergic co-stimulation directly affects GABA-induced Cl--fluxes, with the size of glutamatergic effects depending on the conductance, the decay kinetics, and localization of glutamatergic inputs. We also show that the glutamatergic shift in GABAergic Cl--fluxes is surprisingly stable over a substantial range of latencies between glutamatergic and GABAergic inputs. We conclude from these results that glutamatergic co-stimulation alters GABAergic Cl--fluxes and in turn affects the strength of GABAergic inhibition. These coincidence-dependent ionic changes should be considered as a relevant factor of short-term plasticity in the CNS.
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Affiliation(s)
- Aniello Lombardi
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Mainz, Germany
| | - Peter Jedlicka
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Giessen, Germany
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
| | - Heiko J. Luhmann
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Mainz, Germany
- * E-mail:
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Koster AK, Reese AL, Kuryshev Y, Wen X, McKiernan KA, Gray EE, Wu C, Huguenard JR, Maduke M, Du Bois J. Development and validation of a potent and specific inhibitor for the CLC-2 chloride channel. Proc Natl Acad Sci U S A 2020; 117:32711-32721. [PMID: 33277431 PMCID: PMC7768775 DOI: 10.1073/pnas.2009977117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CLC-2 is a voltage-gated chloride channel that is widely expressed in mammalian tissues. In the central nervous system, CLC-2 appears in neurons and glia. Studies to define how this channel contributes to normal and pathophysiological function in the central nervous system raise questions that remain unresolved, in part due to the absence of precise pharmacological tools for modulating CLC-2 activity. Herein, we describe the development and optimization of AK-42, a specific small-molecule inhibitor of CLC-2 with nanomolar potency (IC50 = 17 ± 1 nM). AK-42 displays unprecedented selectivity (>1,000-fold) over CLC-1, the closest CLC-2 homolog, and exhibits no off-target engagement against a panel of 61 common channels, receptors, and transporters expressed in brain tissue. Computational docking, validated by mutagenesis and kinetic studies, indicates that AK-42 binds to an extracellular vestibule above the channel pore. In electrophysiological recordings of mouse CA1 hippocampal pyramidal neurons, AK-42 acutely and reversibly inhibits CLC-2 currents; no effect on current is observed on brain slices taken from CLC-2 knockout mice. These results establish AK-42 as a powerful tool for investigating CLC-2 neurophysiology.
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Affiliation(s)
- Anna K Koster
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Austin L Reese
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Yuri Kuryshev
- Charles River Laboratories Cleveland, Inc., Cleveland, OH 44128
| | - Xianlan Wen
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Keri A McKiernan
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Erin E Gray
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Caiyun Wu
- Charles River Laboratories Cleveland, Inc., Cleveland, OH 44128
| | - John R Huguenard
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305;
| | - Merritt Maduke
- Department of Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305;
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305;
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61
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Virtanen MA, Uvarov P, Hübner CA, Kaila K. NKCC1, an Elusive Molecular Target in Brain Development: Making Sense of the Existing Data. Cells 2020; 9:cells9122607. [PMID: 33291778 PMCID: PMC7761970 DOI: 10.3390/cells9122607] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
Ionotropic GABA transmission is mediated by anion (mainly Cl−)-permeable GABAA receptors (GABAARs). In immature neurons, GABA exerts depolarizing and sometimes functionally excitatory actions, based on active uptake of Cl− by the Na-K-2Cl cotransporter NKCC1. While functional evidence firmly shows NKCC1-mediated ion transport in immature and diseased neurons, molecular detection of NKCC1 in the brain has turned out to be extremely difficult. In this review, we describe the highly inconsistent data that are available on the cell type-specific expression patterns of the NKCC1 mRNA and protein in the CNS. We discuss the major technical caveats, including a lack of knock-out-controlled immunohistochemistry in the forebrain, possible effects of alternative splicing on the binding of antibodies and RNA probes, and the wide expression of NKCC1 in different cell types, which make whole-tissue analyses of NKCC1 useless for studying its neuronal expression. We also review novel single-cell RNAseq data showing that most of the NKCC1 in the adult CNS may, in fact, be expressed in non-neuronal cells, especially in glia. As future directions, we suggest single-cell NKCC1 mRNA and protein analyses and the use of genetically tagged endogenous proteins or systematically designed novel antibodies, together with proper knock-out controls, for the visualization of endogenous NKCC1 in distinct brain cell types and their subcellular compartments.
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Affiliation(s)
- Mari A. Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany;
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: ; Tel.: +358-407256759
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Androgenic Modulation of the Chloride Transporter NKCC1 Contributes to Age-dependent Isoflurane Neurotoxicity in Male Rats. Anesthesiology 2020; 133:852-866. [PMID: 32930727 DOI: 10.1097/aln.0000000000003437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Cognitive deficits after perinatal anesthetic exposure are well established outcomes in animal models. This vulnerability is sex-dependent and associated with expression levels of the chloride transporters NKCC1 and KCC2. The hypothesis was that androgen signaling, NKCC1 function, and the age of isoflurane exposure are critical for the manifestation of anesthetic neurotoxicity in male rats. METHODS Flutamide, an androgen receptor antagonist, was administered to male rats on postnatal days 2, 4, and 6 before 6 h of isoflurane on postnatal day 7 (ntotal = 26). Spatial and recognition memory were subsequently tested in adulthood. NKCC1 and KCC2 protein levels were measured from cortical lysates by Western blot on postnatal day 7 (ntotal = 20). Bumetanide, an NKCC1 antagonist, was injected immediately before isoflurane exposure (postnatal day 7) to study the effect of NKCC1 inhibition (ntotal = 48). To determine whether male rats remain vulnerable to anesthetic neurotoxicity as juveniles, postnatal day 14 animals were exposed to isoflurane and assessed as adults (ntotal = 30). RESULTS Flutamide-treated male rats exposed to isoflurane successfully navigated the spatial (Barnes maze probe trial F[1, 151] = 78; P < 0.001; mean goal exploration ± SD, 6.4 ± 3.9 s) and recognition memory tasks (mean discrimination index ± SD, 0.09 ± 0.14; P = 0.003), unlike isoflurane-exposed controls. Flutamide changed expression patterns of NKCC1 (mean density ± SD: control, 1.49 ± 0.69; flutamide, 0.47 ± 0.11; P < 0.001) and KCC2 (median density [25th percentile, 75th percentile]: control, 0.23 [0.13, 0.49]; flutamide, 1.47 [1.18,1.62]; P < 0.001). Inhibiting NKCC1 with bumetanide was protective for spatial memory (probe trial F[1, 162] = 6.6; P = 0.011; mean goal time, 4.6 [7.4] s). Delaying isoflurane exposure until postnatal day 14 in males preserved spatial memory (probe trial F[1, 140] = 28; P < 0.001; mean goal time, 6.1 [7.0] s). CONCLUSIONS Vulnerability to isoflurane neurotoxicity is abolished by blocking the androgen receptor, disrupting the function of NKCC1, or delaying the time of exposure to at least 2 weeks of age in male rats. These results support a dynamic role for androgens and chloride transporter proteins in perinatal anesthetic neurotoxicity. EDITOR’S PERSPECTIVE
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Dumon C, Belaidouni Y, Diabira D, Appleyard SM, Wayman GA, Gaiarsa JL. Leptin down-regulates KCC2 activity and controls chloride homeostasis in the neonatal rat hippocampus. Mol Brain 2020; 13:151. [PMID: 33183317 PMCID: PMC7661183 DOI: 10.1186/s13041-020-00689-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/28/2020] [Indexed: 11/10/2022] Open
Abstract
The canonical physiological role of leptin is to regulate hunger and satiety acting on specific hypothalamic nuclei. Beyond this key metabolic function; leptin also regulates many aspects of development and functioning of neuronal hippocampal networks throughout life. Here we show that leptin controls chloride homeostasis in the developing rat hippocampus in vitro. The effect of leptin relies on the down-regulation of the potassium/chloride extruder KCC2 activity and is present during a restricted period of postnatal development. This study confirms and extends the role of leptin in the ontogenesis of functional GABAergic inhibition and helps understanding how abnormal levels of leptin may contribute to neurological disorders.
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Affiliation(s)
- Camille Dumon
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
- Neurochlore Parc Scientifique et Technologique de Luminy, Bâtiment Beret Delaage, Zone Luminy Entreprises Biotech, Marseille, France
| | - Yasmine Belaidouni
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Diabe Diabira
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA
| | - Jean-Luc Gaiarsa
- Aix-Marseille Univ UMR 1249, INSERM (Institut National de La Santé et de La Recherche Médicale) Unité 1249, INMED (Institut de Neurobiologie de La Méditerranée), Parc Scientifique de Luminy, Marseille, France.
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64
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Kolbaev SN, Mohapatra N, Chen R, Lombardi A, Staiger JF, Luhmann HJ, Jedlicka P, Kilb W. NKCC-1 mediated Cl - uptake in immature CA3 pyramidal neurons is sufficient to compensate phasic GABAergic inputs. Sci Rep 2020; 10:18399. [PMID: 33110147 PMCID: PMC7591924 DOI: 10.1038/s41598-020-75382-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
Activation of GABAA receptors causes in immature neurons a functionally relevant decrease in the intracellular Cl- concentration ([Cl-]i), a process termed ionic plasticity. Amount and duration of ionic plasticity depends on kinetic properties of [Cl-]i homeostasis. In order to characterize the capacity of Cl- accumulation and to quantify the effect of persistent GABAergic activity on [Cl-]i, we performed gramicidin-perforated patch-clamp recordings from CA3 pyramidal neurons of immature (postnatal day 4-7) rat hippocampal slices. These experiments revealed that inhibition of NKCC1 decreased [Cl-]i toward passive distribution with a time constant of 381 s. In contrast, active Cl- accumulation occurred with a time constant of 155 s, corresponding to a rate of 15.4 µM/s. Inhibition of phasic GABAergic activity had no significant effect on steady state [Cl-]i. Inhibition of tonic GABAergic currents induced a significant [Cl-]i increase by 1.6 mM, while activation of tonic extrasynaptic GABAA receptors with THIP significantly reduced [Cl-]i.. Simulations of neuronal [Cl-]i homeostasis supported the observation, that basal levels of synaptic GABAergic activation do not affect [Cl-]i. In summary, these results indicate that active Cl--uptake in immature hippocampal neurons is sufficient to maintain stable [Cl-]i at basal levels of phasic and to some extent also to compensate tonic GABAergic activity.
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Affiliation(s)
- Sergey N Kolbaev
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.,Research Center of Neurology, Volokolamskoyeshosse, 80, Moscow, Russia, 125367
| | - Namrata Mohapatra
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Rongqing Chen
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.,Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Aniello Lombardi
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Jochen F Staiger
- Institute of Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, Kreuzbergring 36, 37075, Göttingen, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.,ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Rudolf-Buchheim-Str. 6, 35392, Giessen, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center Mainz, Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
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65
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Raveendran VA, Pressey JC, Woodin MA. A Novel Small Molecule Targets NKCC1 To Restore Synaptic Inhibition. Trends Pharmacol Sci 2020; 41:897-899. [PMID: 33097285 DOI: 10.1016/j.tips.2020.10.002] [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] [Received: 10/02/2020] [Accepted: 10/02/2020] [Indexed: 11/25/2022]
Abstract
Finely tuned excitation-inhibition balance is essential for proper brain function, and loss of balance resulting from reduced synaptic inhibition is associated with neurological disorders. Savardi and colleagues have discovered a novel inhibitor of a cation-chloride transporter that is required for synaptic inhibition, and which restores behaviors associated with Down syndrome (DS) and autism spectrum disorder (ASD).
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Affiliation(s)
- Vineeth A Raveendran
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Jessica C Pressey
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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66
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Thakran S, Guin D, Singh P, Singh P, Kukal S, Rawat C, Yadav S, Kushwaha SS, Srivastava AK, Hasija Y, Saso L, Ramachandran S, Kukreti R. Genetic Landscape of Common Epilepsies: Advancing towards Precision in Treatment. Int J Mol Sci 2020; 21:E7784. [PMID: 33096746 PMCID: PMC7589654 DOI: 10.3390/ijms21207784] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
Epilepsy, a neurological disease characterized by recurrent seizures, is highly heterogeneous in nature. Based on the prevalence, epilepsy is classified into two types: common and rare epilepsies. Common epilepsies affecting nearly 95% people with epilepsy, comprise generalized epilepsy which encompass idiopathic generalized epilepsy like childhood absence epilepsy, juvenile myoclonic epilepsy, juvenile absence epilepsy and epilepsy with generalized tonic-clonic seizure on awakening and focal epilepsy like temporal lobe epilepsy and cryptogenic focal epilepsy. In 70% of the epilepsy cases, genetic factors are responsible either as single genetic variant in rare epilepsies or multiple genetic variants acting along with different environmental factors as in common epilepsies. Genetic testing and precision treatment have been developed for a few rare epilepsies and is lacking for common epilepsies due to their complex nature of inheritance. Precision medicine for common epilepsies require a panoramic approach that incorporates polygenic background and other non-genetic factors like microbiome, diet, age at disease onset, optimal time for treatment and other lifestyle factors which influence seizure threshold. This review aims to comprehensively present a state-of-art review of all the genes and their genetic variants that are associated with all common epilepsy subtypes. It also encompasses the basis of these genes in the epileptogenesis. Here, we discussed the current status of the common epilepsy genetics and address the clinical application so far on evidence-based markers in prognosis, diagnosis, and treatment management. In addition, we assessed the diagnostic predictability of a few genetic markers used for disease risk prediction in individuals. A combination of deeper endo-phenotyping including pharmaco-response data, electro-clinical imaging, and other clinical measurements along with genetics may be used to diagnose common epilepsies and this marks a step ahead in precision medicine in common epilepsies management.
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Affiliation(s)
- Sarita Thakran
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Debleena Guin
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Department of Bioinformatics, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;
| | - Pooja Singh
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Priyanka Singh
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Samiksha Kukal
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Chitra Rawat
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Saroj Yadav
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
| | - Suman S. Kushwaha
- Department of Neurology, Institute of Human Behaviour and Allied Sciences, Dilshad Garden, Delhi 110095, India;
| | - Achal K. Srivastava
- Department of Neurology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India;
| | - Yasha Hasija
- Department of Bioinformatics, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;
| | - Luciano Saso
- Department of Physiology and Pharmacology “Vittorio Erspamer”, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy;
| | - Srinivasan Ramachandran
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
- G N Ramachandran Knowledge Centre, Council of Scientific and Industrial Research (CSIR)—Institute of Genomics and Integrative Biology (IGIB), New Delhi 110007, India
| | - Ritushree Kukreti
- Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology (IGIB), Council of Scientific and Industrial Research (CSIR), Delhi 110007, India; (S.T.); (D.G.); (P.S.); (P.S.); (S.K.); (C.R.); (S.Y.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India;
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67
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Lee JW. Protonic conductor: better understanding neural resting and action potential. J Neurophysiol 2020; 124:1029-1044. [PMID: 32816602 DOI: 10.1152/jn.00281.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
With the employment of the transmembrane electrostatic proton localization theory with a new membrane potential equation, neural resting and action potential is now much better understood as the voltage contributed by the localized protons/cations at a neural liquid- membrane interface. Accordingly, the neural resting/action potential is essentially a protonic/cationic membrane capacitor behavior. It is now understood with a newly formulated action potential equation: when action potential is <0 (negative number), the localized protons/cations charge density at the liquid-membrane interface along the periplasmic side is >0 (positive number); when the action potential is >0, the concentration of the localized protons and localized nonproton cations is <0, indicating a "depolarization" state. The nonlinear curve of the localized protons/cations charge density in the real-time domain of an action potential spike appears as an inverse mirror image to the action potential. The newly formulated action potential equation provides biophysical insights for neuron electrophysiology, which may represent a complementary development to the classic Goldman-Hodgkin-Katz equation. With the use of the action potential equation, the biological significance of axon myelination is now also elucidated as to provide protonic insulation and prevent any ions both inside and outside of the neuron from interfering with the action potential signal, so that the action potential can quickly propagate along the axon with minimal (e.g., 40 times less) energy requirement.NEW & NOTEWORTHY The newly formulated action potential equation provides biophysical insights for neuron electrophysiology, which may represent a complementary development to the classic Goldman-Hodgkin-Katz equation. The nonlinear curve of the localized protons/cations charge density in the real-time domain of an action potential spike appears as an inverse mirror image to the action potential. The biological significance of axon myelination is now elucidated as to provide protonic insulation and prevent any ions from interfering with action potential signal.
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Affiliation(s)
- James Weifu Lee
- Department of Chemistry & Biochemistry, Old Dominion University, Norfolk, Virginia
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68
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Lee M, Liu YC, Chen C, Lu CH, Lu ST, Huang TN, Hsu MT, Hsueh YP, Cheng PL. Ecm29-mediated proteasomal distribution modulates excitatory GABA responses in the developing brain. J Cell Biol 2020; 219:133566. [PMID: 31910261 PMCID: PMC7041676 DOI: 10.1083/jcb.201903033] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 10/14/2019] [Accepted: 11/13/2019] [Indexed: 12/31/2022] Open
Abstract
Neuronal GABAergic responses switch from excitatory to inhibitory at an early postnatal period in rodents. The timing of this switch is controlled by intracellular Cl− concentrations, but factors determining local levels of cation-chloride cotransporters remain elusive. Here, we report that local abundance of the chloride importer NKCC1 and timely emergence of GABAergic inhibition are modulated by proteasome distribution, which is mediated through interactions of proteasomes with the adaptor Ecm29 and the axon initial segment (AIS) scaffold protein ankyrin G. Mechanistically, both the Ecm29 N-terminal domain and an intact AIS structure are required for transport and tethering of proteasomes in the AIS region. In mice, Ecm29 knockout (KO) in neurons increases the density of NKCC1 protein in the AIS region, a change that positively correlates with a delay in the GABAergic response switch. Phenotypically, Ecm29 KO mice showed increased firing frequency of action potentials at early postnatal ages and were hypersusceptible to chemically induced convulsive seizures. Finally, Ecm29 KO neurons exhibited accelerated AIS developmental positioning, reflecting a perturbed AIS morphological plastic response to hyperexcitability arising from proteasome inhibition, a phenotype rescued by ectopic Ecm29 expression or NKCC1 inhibition. Together, our findings support the idea that neuronal maturation requires regulation of proteasomal distribution controlled by Ecm29.
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Affiliation(s)
- Min Lee
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yen-Chen Liu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chen Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chi-Huan Lu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Shao-Tzu Lu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Tzyy-Nan Huang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Meng-Tsung Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Pei-Lin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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69
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Postnatal Overnutrition Induces Changes in Synaptic Transmission to Leptin Receptor-Expressing Neurons in the Arcuate Nucleus of Female Mice. Nutrients 2020; 12:nu12082425. [PMID: 32823489 PMCID: PMC7468987 DOI: 10.3390/nu12082425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/22/2022] Open
Abstract
The adipocyte-derived hormone leptin is a potent neurotrophic factor that contributes to the neural plasticity and development of feeding circuitry, particularly in the arcuate nucleus of the hypothalamus (ARH). Postnatal overnutrition affects leptin secretion and sensitivity, but whether postnatal overnutrition produces changes in the development of the synaptic transmission to ARH neurons is currently unknown. We evaluated the excitatory and inhibitory currents to ARH leptin receptor (LepR)-expressing neurons in prepubertal, pubertal and adult female mice. The effects of postnatal overnutrition in the expression of genes that code ion channels subunits in the ARH were also evaluated. We observed that the transition from prepubertal to pubertal stage is characterized by a rise in both excitatory and inhibitory transmission to ARH LepR-expressing neurons in control mice. Postnatal overnutrition induces a further increase in the excitatory synaptic transmission in pubertal and adult animals, whereas the amplitude of inhibitory currents to ARH LepR-expressing cells was reduced. Postnatal overnutrition also contributes to the modulation of gene expression of N-methyl-D-aspartate, GABAB and ATP-sensitive potassium channel subunits in ARH. In summary, the synaptic transmission to ARH cells is profoundly influenced by postnatal overnutrition. Thus, increased adiposity during early postnatal period induces long-lasting effects on ARH cellular excitability.
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70
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Han P, Welsh CT, Smith MT, Schmidt RE, Carroll SL. Complex Patterns of GABAergic Neuronal Deficiency and Type 2 Potassium-Chloride Cotransporter Immaturity in Human Focal Cortical Dysplasia. J Neuropathol Exp Neurol 2020; 78:365-372. [PMID: 30856249 DOI: 10.1093/jnen/nlz009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Focal cortical dysplasia (FCD) is a common histopathologic finding in cortical specimens resected for refractory epilepsy. GABAergic neuronal abnormalities and K-Cl cotransporter type 2 (KCC2) immaturity may be contributing factors for FCD-related epilepsy. We examined surgical specimens from 12 cases diagnosed with FCD, and brain tissues without developmental abnormality obtained from 6 autopsy cases. We found that GABAergic neuronal density was abnormal in FCD with 2 distinct patterns. In 7 of 12 (58%) FCD subjects, the GABAergic neuron density in dysplastic regions and in neighboring nondysplastic regions was equally reduced, hence we call this a "broad pattern." In the remaining cases, GABAergic neuron density was decreased in dysplastic regions but not in the neighboring nondysplastic regions; we designate this "restricted pattern." The different patterns are not associated with pathologic subtypes of FCD. Intracytoplasmic retention of KCC2 is evident in dysmorphic neurons in the majority of FCD type II subjects (5/7) but not in FCD type I. Our study suggests that (1) "broad" GABAergic deficiency may reflect epileptic vulnerability outside the dysplastic area; and (2) abnormal distribution of KCC2 may contribute to seizure generation in patients with FCD type II but not in type I.
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Affiliation(s)
- Pengcheng Han
- Department of Pathology and Laboratory Medicine.,Department of Pathology and Laboratory Medicine Residency Program, Medical University of South Carolina, Charleston, South Carolina
| | | | | | - Robert E Schmidt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
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Pietrancosta N, Djibo M, Daumas S, El Mestikawy S, Erickson JD. Molecular, Structural, Functional, and Pharmacological Sites for Vesicular Glutamate Transporter Regulation. Mol Neurobiol 2020; 57:3118-3142. [PMID: 32474835 PMCID: PMC7261050 DOI: 10.1007/s12035-020-01912-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
Vesicular glutamate transporters (VGLUTs) control quantal size of glutamatergic transmission and have been the center of numerous studies over the past two decades. VGLUTs contain two independent transport modes that facilitate glutamate packaging into synaptic vesicles and phosphate (Pi) ion transport into the synaptic terminal. While a transmembrane proton electrical gradient established by a vacuolar-type ATPase powers vesicular glutamate transport, recent studies indicate that binding sites and flux properties for chloride, potassium, and protons within VGLUTs themselves regulate VGLUT activity as well. These intrinsic ionic binding and flux properties of VGLUTs can therefore be modulated by neurophysiological conditions to affect levels of glutamate available for release from synapses. Despite their extraordinary importance, specific and high-affinity pharmacological compounds that interact with these sites and regulate VGLUT function, distinguish between the various modes of transport, and the different isoforms themselves, are lacking. In this review, we provide an overview of the physiologic sites for VGLUT regulation that could modulate glutamate release in an over-active synapse or in a disease state.
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Affiliation(s)
- Nicolas Pietrancosta
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Laboratoire des Biomolécules, Sorbonne Université, CNRS, ENS, LBM, 75005, Paris, France.
| | - Mahamadou Djibo
- Sorbonne Paris Cité, Université Paris Descartes, LCBPT, UMR 8601, 75006, Paris, France
| | - Stephanie Daumas
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France
| | - Salah El Mestikawy
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS) INSERM, CNRS, Sorbonne Université, Paris, France. .,Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 boulevard Lasalle, Verdun, Montreal, QC, Canada.
| | - Jeffrey D Erickson
- Neuroscience Center, Louisiana State University, New Orleans, LA, 70112, USA. .,Department of Pharmacology, Louisiana State University, New Orleans, LA, 70112, USA.
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Zhao M, Zhang J, Huang W, Dong J, Guo J, U KP, Weng Z, Liu S, Chan HC, Feng H, Jiang X. CFTR promotes malignant glioma development via up-regulation of Akt/Bcl2-mediated anti-apoptosis pathway. J Cell Mol Med 2020; 24:7301-7312. [PMID: 32463592 PMCID: PMC7339181 DOI: 10.1111/jcmm.15300] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/04/2020] [Accepted: 03/27/2020] [Indexed: 12/28/2022] Open
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP‐activated Cl‐ channel, is extensively expressed in the epithelial cells of various tissues and organs. Accumulating evidence indicates that aberrant expression or mutation of CFTR is related to carcinoma development. Malignant gliomas are the most common and aggressive intracranial tumours; however, the role of CFTR in the development of malignant gliomas is unclear. Here, we report that CFTR is expressed in malignant glioma cell lines. Suppression of CFTR channel function or knockdown of CFTR suppresses glioma cell viability whereas overexpression of CFTR promotes it. Additionally, overexpression of CFTR suppresses apoptosis and promotes glioma progression in both subcutaneous and orthotopic xenograft models. Cystic fibrosis transmembrane conductance regulator activates Akt/Bcl2 pathway, and suppression of PI3K/Akt pathway abolishes CFTR overexpression–induced up‐regulation of Bcl2 (MK‐2206 and LY294002) and cell viability (MK‐2206). More importantly, the protein expression level of CFTR is significantly increased in glioblastoma patient samples. Altogether, our study has revealed a mechanism by which CFTR promotes glioma progression via up‐regulation of Akt/Bcl2‐mediated anti‐apoptotic pathway, which warrants future studies into the potential of using CFTR as a therapeutic target for glioma treatment.
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Affiliation(s)
- Mingyue Zhao
- Department of Neurosurgery, Airforce General Hospital of the PLA, Beijing, China.,Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jieting Zhang
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Wenqing Huang
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.,Department of Transfusion Medicine, Shenzhen Hospital, Southern Medical University, Shenzhen, China
| | - Jianda Dong
- Department of Pathology, Ningxia Medical University, Yinchuan, China
| | - Jinghui Guo
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kin Pong U
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - ZhiHui Weng
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Si Liu
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Hsiao Chang Chan
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.,School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xiaohua Jiang
- Epithelial Cell Biology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China.,Key Laboratory for Regenerative Medicine of the Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.,School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
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73
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Li C, Lei Y, Tian Y, Xu S, Shen X, Wu H, Bao S, Wang F. The etiological contribution of GABAergic plasticity to the pathogenesis of neuropathic pain. Mol Pain 2020; 15:1744806919847366. [PMID: 30977423 PMCID: PMC6509976 DOI: 10.1177/1744806919847366] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neuropathic pain developing after peripheral or central nerve injury is the result of pathological changes generated through complex mechanisms. Disruption in the homeostasis of excitatory and inhibitory neurons within the central nervous system is a crucial factor in the formation of hyperalgesia or allodynia occurring with neuropathic pain. The central GABAergic pathway has received attention for its extensive distribution and function in neural circuits, including the generation and development of neuropathic pain. GABAergic inhibitory changes that occur in the interneurons along descending modulatory and nociceptive pathways in the central nervous system are believed to generate neuronal plasticity, such as synaptic plasticity or functional plasticity of the related genes or proteins, that is the foundation of persistent neuropathic pain. The primary GABAergic plasticity observed in neuropathic pain includes GABAergic synapse homo- and heterosynaptic plasticity, decreased synthesis of GABA, down-expression of glutamic acid decarboxylase and GABA transporter, abnormal expression of NKCC1 or KCC2, and disturbed function of GABA receptors. In this review, we describe possible mechanisms associated with GABAergic plasticity, such as central sensitization and GABAergic interneuron apoptosis, and the epigenetic etiologies of GABAergic plasticity in neuropathic pain. Moreover, we summarize potential therapeutic targets of GABAergic plasticity that may allow for successful relief of hyperalgesia from nerve injury. Finally, we compare the effects of the GABAergic system in neuropathic pain to other types of chronic pain to understand the contribution of GABAergic plasticity to neuropathic pain.
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Affiliation(s)
- Caijuan Li
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Yanying Lei
- 2 Department of Stomatology, Affiliated Hospital of Qinghai University, Xining, China
| | - Yi Tian
- 3 Department of Anesthesiology, Haikou Affiliated Hospital of Xiangya Medical School, Central South University, Haikou People's Hospital, Haikou, China
| | - Shiqin Xu
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Xiaofeng Shen
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Haibo Wu
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Senzhu Bao
- 2 Department of Stomatology, Affiliated Hospital of Qinghai University, Xining, China
| | - Fuzhou Wang
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China.,4 Group of Neuropharmacology and Neurophysiology, Division of Neuroscience, The Bonoi Academy of Science and Education, Chapel Hill, NC, USA
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74
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Human Pluripotent Stem Cell-Derived Neurons Are Functionally Mature In Vitro and Integrate into the Mouse Striatum Following Transplantation. Mol Neurobiol 2020; 57:2766-2798. [PMID: 32356172 PMCID: PMC7253531 DOI: 10.1007/s12035-020-01907-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 03/23/2020] [Indexed: 01/23/2023]
Abstract
Human pluripotent stem cells (hPSCs) are a powerful tool for modelling human development. In recent years, hPSCs have become central in cell-based therapies for neurodegenerative diseases given their potential to replace affected neurons. However, directing hPSCs into specific neuronal types is complex and requires an accurate protocol that mimics endogenous neuronal development. Here we describe step-by-step a fast feeder-free neuronal differentiation protocol to direct hPSCs to mature forebrain neurons in 37 days in vitro (DIV). The protocol is based upon a combination of specific morphogens, trophic and growth factors, ions, neurotransmitters and extracellular matrix elements. A human-induced PSC line (Ctr-Q33) and a human embryonic stem cell line (GEN-Q18) were used to reinforce the potential of the protocol. Neuronal activity was analysed by single-cell calcium imaging. At 8 DIV, we obtained a homogeneous population of hPSC-derived neuroectodermal progenitors which self-arranged in bi-dimensional neural tube-like structures. At 16 DIV, we generated hPSC-derived neural progenitor cells (NPCs) with mostly a subpallial identity along with a subpopulation of pallial NPCs. Terminal in vitro neuronal differentiation was confirmed by the expression of microtubule associated protein 2b (Map 2b) by almost 100% of hPSC-derived neurons and the expression of specific-striatal neuronal markers including GABA, CTIP2 and DARPP-32. HPSC-derived neurons showed mature and functional phenotypes as they expressed synaptic markers, voltage-gated ion channels and neurotransmitter receptors. Neurons displayed diverse spontaneous activity patterns that were classified into three major groups, namely “high”, “intermediate” and “low” firing neurons. Finally, transplantation experiments showed that the NPCs survived and differentiated within mouse striatum for at least 3 months. NPCs integrated host environmental cues and differentiated into striatal medium-sized spiny neurons (MSNs), which successfully integrated into the endogenous circuitry without teratoma formation. Altogether, these findings demonstrate the potential of this robust human neuronal differentiation protocol, which will bring new opportunities for the study of human neurodevelopment and neurodegeneration, and will open new avenues in cell-based therapies, pharmacological studies and alternative in vitro toxicology.
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75
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Çomakli S, Özdemir S, Değirmençay Ş. Canine distemper virus induces downregulation of GABA A,GABA B, and GAT1 expression in brain tissue of dogs. Arch Virol 2020; 165:1321-1331. [PMID: 32253618 DOI: 10.1007/s00705-020-04617-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/11/2020] [Indexed: 02/08/2023]
Abstract
The aim of the study was to determine the expression profiles of GABAA, GABAB, and GAT1 using RT-PCR and the immunoreactivity of GAT1 via immunohistochemical and immunofluorescence assays in CDV-infected brain tissue of dogs. For this purpose, dogs with CDV and dogs without CDV were selected. The mRNA transcript levels of GABAA, GABAB, and GAT1 were significantly downregulated in brain tissue in the CDV-infected group as compared with that in non-CDV-infected brain tissue in the control group (p < 0.01, p < 0.001). In addition, the immunoreactivity of GAT1 in CDV-infected brain tissue was significantly lower than in the uninfected group (p < 0.05). We conclude that one of the main causes of myoclonus in CDV infections may be the blockage of postsynaptic inhibition in neurons or a lack of metabolism of GABA. In addition, a GABA neurotransmission imbalance could play a role in demyelination in CDV infections.
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Affiliation(s)
- Selim Çomakli
- Department of Pathology, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey.
| | - Selçuk Özdemir
- Department of Genetic, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
| | - Şükrü Değirmençay
- Department of Internal Medicine, Faculty of Veterinary Medicine, Atatürk University, Erzurum, Turkey
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76
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Scheyer AF, Borsoi M, Wager-Miller J, Pelissier-Alicot AL, Murphy MN, Mackie K, Manzoni OJJ. Cannabinoid Exposure via Lactation in Rats Disrupts Perinatal Programming of the Gamma-Aminobutyric Acid Trajectory and Select Early-Life Behaviors. Biol Psychiatry 2020; 87:666-677. [PMID: 31653479 PMCID: PMC7056509 DOI: 10.1016/j.biopsych.2019.08.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 01/22/2023]
Abstract
BACKGROUND Cannabis usage is increasing with its widespread legalization. Cannabis use by mothers during lactation transfers active cannabinoids to the developing offspring during this critical period and alters postnatal neurodevelopment. A key neurodevelopmental landmark is the excitatory to inhibitory gamma-aminobutyric acid (GABA) switch caused by reciprocal changes in expression ratios of the K+/Cl- transporters potassium-chloride cotransporter 2 (KCC2) and sodium-potassium-chloride transporter (NKCC1). METHODS Rat dams were treated with Δ9-tetrahydrocannabinol or a synthetic cannabinoid during the first 10 days of postnatal development, and experiments were then conducted in the offspring exposed to these drugs via lactation. The network influence of GABA transmission was analyzed using cell-attached recordings. KCC2 and NKCC1 levels were determined using Western blot and quantitative polymerase chain reaction analyses. Ultrasonic vocalization and homing behavioral experiments were carried out at relevant time points. RESULTS Treating rat dams with cannabinoids during early lactation retards transcriptional upregulation and expression of KCC2, thereby delaying the GABA switch in pups of both sexes. This perturbed trajectory was corrected by the NKCC1 antagonist bumetanide and accompanied by alterations in ultrasonic vocalization without changes in homing behavior. Neurobehavioral deficits were prevented by CB1 receptor antagonism during maternal exposure, showing that the CB1 receptor underlies the cannabinoid-induced alterations. CONCLUSIONS These results reveal how perinatal cannabinoid exposure retards an early milestone of development, delaying the trajectory of GABA's polarity transition and altering early-life communication.
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Affiliation(s)
- Andrew F Scheyer
- Institut de neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale U1249, Marseille, France; Aix-Marseille University, Marseille, France; Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University
| | - Milene Borsoi
- Institut de neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale U1249, Marseille, France; Aix-Marseille University, Marseille, France; Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University
| | - Jim Wager-Miller
- Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University; Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana; Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana
| | - Anne-Laure Pelissier-Alicot
- Institut de neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale U1249, Marseille, France; Aix-Marseille University, Marseille, France; Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University; Service de Psychiatrie, CHU Conception, Assistance Publique - Hôpitaux de Marseille, Marseille, France; Service de Médecine Légale, CHU Timone-Adultes, Assistance Publique - Hôpitaux de Marseille, Marseille, France
| | - Michelle N Murphy
- Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University; Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana; Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana
| | - Ken Mackie
- Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University; Gill Center for Biomolecular Science, Indiana University, Bloomington, Indiana; Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana.
| | - Olivier J J Manzoni
- Institut de neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale U1249, Marseille, France; Aix-Marseille University, Marseille, France; Cannalab, Cannabinoids Neuroscience Research International Associated Laboratory, Institut National de la Santé et de la Recherche Médicale-Aix-Marseille University/Indiana University.
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77
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Fukuda A. Chloride homeodynamics underlying modal shifts in cellular and network oscillations. Neurosci Res 2020; 156:14-23. [PMID: 32105770 DOI: 10.1016/j.neures.2020.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 11/22/2019] [Accepted: 02/21/2020] [Indexed: 11/16/2022]
Abstract
γ-Aminobutyric acid (GABA) generally induces hyperpolarization and inhibition in the adult brain, but causes depolarization (and can be excitatory) in the immature brain. Depolarizing GABA actions are necessary for neurogenesis, differentiation, migration, and synaptogenesis. Additionally, the conversion of GABA responses from inhibition to excitation can be induced in adults by pathological conditions. Because GABAA receptors are Cl- channels, alternating GABA actions between hyperpolarization (Cl- influx) and depolarization (Cl- efflux) are induced by changes in the Cl- gradient, which is regulated by C- transporters. Thus, the dynamics of neural functions are modulated by active Cl- homeostasis (Cl- homeodynamics), alternating inhibition and excitation, and could underlie the modal shifts in cellular and network oscillations. Such a modal shift in GABA actions is required for normal development. Thus disturbances in this developmental GABA modal shift and/or the induction of excitatory GABA action in adult could underlie the pathogenesis of diverse neurological diseases (so-called network diseases).
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Affiliation(s)
- Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan; Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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78
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Abstract
The GABA response switch from excitatory to inhibitory is a key event in neuronal maturation that depends on the regulated expression of chloride transporters NKCC1 and KCC2. In this issue, Lee et al. (2020. J. Cell. Biol.https://doi.org/10.1083/jcb.201903033) describe how degradation of NKCC1 by proteasomes immobilized at the axon initial segment (AIS) by the Ecm29 adaptor contributes to this regulation, driving the GABA switch and the positional maturation of the AIS.
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Affiliation(s)
- Christophe Leterrier
- Aix Marseille Université, Centre National de la Recherche Scientifique, Institute of NeuroPhysiopathology UMR7051, NeuroCyto, Marseille, France
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79
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Abstract
This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.
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80
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Kfir A, Awasthi R, Ghosh S, Kundu S, Paul B, Lamprecht R, Barkai E. A Cellular Mechanism of Learning-Induced Enhancement of Synaptic Inhibition: PKC-Dependent Upregulation of KCC2 Activation. Sci Rep 2020; 10:962. [PMID: 31969605 PMCID: PMC6976593 DOI: 10.1038/s41598-020-57626-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 12/18/2019] [Indexed: 01/23/2023] Open
Abstract
Long-term memory of complex olfactory learning is expressed by wide spread enhancement in excitatory and inhibitory synaptic transmission onto piriform cortex pyramidal neurons. A particularly interesting modification in synaptic inhibition is the hyperpolarization of the reversal potential of the fast post synaptic inhibitory potential (fIPSP). Here we study the mechanism underlying the maintenance of such a shift in the fIPSP. Blocking of the neuronal specific K+-Cl- co-transporter (KCC2) in neurons of trained rats significantly depolarized the averaged fIPSP reversal potential of the spontaneous miniature inhibitory post synaptic currents (mIPSCs), to the averaged pre-training level. A similar effect was obtained by blocking PKC, which was previously shown to upregulate KCC2. Accordingly, the level of PKC-dependent phosphorylation of KCC2, at the serine 940 site, was significantly increased after learning. In contrast, blocking two other key second messenger systems CaMKII and PKA, which have no phosphorylation sites on KCC2, had no effect on the fIPSP reversal potential. Importantly, the PKC inhibitor also reduced the averaged amplitude of the spontaneous miniature excitatory synaptic currents (mEPSCs) in neurons of trained rats only, to the pre-training level. We conclude that learning-induced hyper-polarization of the fIPSP reversal potential is mediated by PKC-dependent increase of KCC2 phosphorylation.
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Affiliation(s)
- Adi Kfir
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Richa Awasthi
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Sourav Ghosh
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Sankhanava Kundu
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Blesson Paul
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Raphael Lamprecht
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Edi Barkai
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel.
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81
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Liu R, Wang J, Liang S, Zhang G, Yang X. Role of NKCC1 and KCC2 in Epilepsy: From Expression to Function. Front Neurol 2020; 10:1407. [PMID: 32010056 PMCID: PMC6978738 DOI: 10.3389/fneur.2019.01407] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 12/23/2019] [Indexed: 01/21/2023] Open
Abstract
As a main inhibitory neurotransmitter in the central nervous system, γ-aminobutyric acid (GABA) activates chloride-permeable GABAa receptors (GABAa Rs) and induces chloride ion (Cl−) flow, which relies on the intracellular chloride concentration ([Cl−]i) of the postsynaptic neuron. The Na-K-2Cl cotransporter isoform 1 (NKCC1) and the K-Cl cotransporter isoform 2 (KCC2) are two main cation-chloride cotransporters (CCCs) that have been implicated in human epilepsy. NKCC1 and KCC2 reset [Cl−]i by accumulating and extruding Cl−, respectively. Previous studies have shown that the profile of NKCC1 and KCC2 in neonatal neurons may reappear in mature neurons under some pathophysiological conditions, such as epilepsy. Although increasing studies focusing on the expression of NKCC1 and KCC2 have suggested that impaired chloride plasticity may be closely related to epilepsy, additional neuroelectrophysiological research aimed at studying the functions of NKCC1 and KCC2 are needed to understand the exact mechanism by which they induce epileptogenesis. In this review, we aim to briefly summarize the current researches surrounding the expression and function of NKCC1 and KCC2 in epileptogenesis and its implications on the treatment of epilepsy. We will also explore the potential for NKCC1 and KCC2 to be therapeutic targets for the development of novel antiepileptic drugs.
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Affiliation(s)
- Ru Liu
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Junling Wang
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Shuli Liang
- Department of Functional Neurosurgery, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Guojun Zhang
- Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaofeng Yang
- Neuroelectrophysiological Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Center of Epilepsy, Center for Brain Disorders Research, Capital Medical University, Beijing, China.,Center of Epilepsy, Beijing Institute of Brain Disorders, Beijing, China.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
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Tanveer M, Shabala S. Neurotransmitters in Signalling and Adaptation to Salinity Stress in Plants. NEUROTRANSMITTERS IN PLANT SIGNALING AND COMMUNICATION 2020. [DOI: 10.1007/978-3-030-54478-2_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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83
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Yang XL, Zeng ML, Shao L, Jiang GT, Cheng JJ, Chen TX, Han S, Yin J, Liu WH, He XH, Peng BW. NFAT5 and HIF-1α Coordinate to Regulate NKCC1 Expression in Hippocampal Neurons After Hypoxia-Ischemia. Front Cell Dev Biol 2019; 7:339. [PMID: 31921851 PMCID: PMC6923656 DOI: 10.3389/fcell.2019.00339] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/29/2019] [Indexed: 12/22/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with severe long-term sequelae such as cerebral palsy, epilepsy and cognitive disabilities. Na+-K+-2Cl– cotransporters 1 (NKCC1) is dramatically upregulated after hypoxia-ischemia (HI), which aggravates brain edema and brain damage. Clinically, an NKCC1-specific inhibitor, bumetanide, is used to treat diseases related to aberrant NKCC1 expression, but the underlying mechanism of aberrant NKCC1 expression has rarely been studied in HIE. In this study, the cooperative effect of hypoxia-inducible factor-1α (HIF-1α) and nuclear factor of activated T cells 5 (NFAT5) on NKCC1 expression was explored in hippocampal neurons under hypoxic conditions. HI increased HIF-1α nuclear localization and transcriptional activity, and pharmacological inhibition of the HIF-1α transcription activity or mutation of hypoxia responsive element (HRE) motifs recovered the hypoxia-induced aberrant expression and promoter activity of NKCC1. In contrast, oxygen–glucose deprivation (OGD)-induced downregulation of NFAT5 expression was reversed by treating with hypertonic saline, which ameliorated aberrant NKCC1 expression. More importantly, knocking down NFAT5 or mutation of the tonicity enhancer element (TonE) stimulated NKCC1 expression and promoter activity under normal physiological conditions. The positive regulation of NKCC1 by HIF-1α and the negative regulation of NKCC1 by NFAT5 may serve to maintain NKCC1 expression levels, which may shed light on the transcription regulation of NKCC1 in hippocampal neurons after hypoxia.
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Affiliation(s)
- Xing-Liang Yang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Meng-Liu Zeng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Lin Shao
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Guang-Tong Jiang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jing-Jing Cheng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Tao-Xiang Chen
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jun Yin
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wan-Hong Liu
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Xiao-Hua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Bi-Wen Peng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
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Gao JL, Peng K, Shen MW, Hou YH, Qian XB, Meng XW, Ji FH, Wang LN, Yang JP. Suppression of WNK1-SPAK/OSR1 Attenuates Bone Cancer Pain by Regulating NKCC1 and KCC2. THE JOURNAL OF PAIN 2019; 20:1416-1428. [PMID: 31085334 DOI: 10.1016/j.jpain.2019.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 04/15/2019] [Accepted: 05/07/2019] [Indexed: 02/06/2023]
Abstract
Our preliminary experiment indicated the activation of with-nolysine kinases 1 (WNK1) in bone cancer pain (BCP) rats. This study aimed to investigate the underlying mechanisms via which WNK1 contributed to BCP. A rat model of BCP was induced by Walker-256 tumor cell implantation. WNK1 expression and distribution in the lumbar spinal cord dorsal horn and dorsal root ganglion were examined. SPS1-related proline/alanine-rich kinase (SPAK), oxidative stress-responsive kinase 1 (OSR1), sodium-potassium-chloride cotransporter 1 (NKCC1), and potassium-chloride cotransporter 2 (KCC2) expression were assessed. Pain behaviors including mechanical allodynia and movement-evoked pain were measured. BCP rats exhibited significant mechanical allodynia, with increased WNK1 expression in the dorsal horn and dorsal root ganglion neurons, elevated SPAK/OSR1 and NKCC1 expression in the dorsal root ganglion, and decreased KCC2 expression in the dorsal horn. WNK1 knock-down by small interfering alleviated mechanical allodynia and movement-evoked pain, inhibited WNK1-SPAK/OSR1-NKCC1 activities, and restored KCC2 expression. In addition, closantel (a WNK1-SPAK/OSR1 inhibitor) improved pain behaviors, downregulated SPAK/OSR1 and NKCC1 expression, and upregulated KCC2 expression in BCP rats. Activation of WNK1-SPAK/OSR1 signaling contributed to BCP in rats by modulating NKCC1 and KCC2 expression. Therefore, suppression of WNK1-SPAK/OSR1 may serve as a potential target for BCP therapy. PERSPECTIVE: Our findings demonstrated that the WNK1-SPAK/OSR1 signaling contributed to BCP in rats via regulating NKCC1 and KCC2. Suppressing this pathway reduced pain behaviors. Based on these findings, the WNK1-SPAK/OSR1 signaling may be a potential target for BCP therapy.
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Affiliation(s)
- Jian-Ling Gao
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Ke Peng
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Meng-Wei Shen
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China; Department of Anesthesiology, Suzhou Municipal Hospital, Nanjing Medical University Affiliated Suzhou Hospital, Suzhou, Jiangsu, China
| | - Yong-Heng Hou
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xiao-Bo Qian
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xiao-Wen Meng
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Fu-Hai Ji
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Li-Na Wang
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jian-Ping Yang
- Department of Anesthesiology, Intensive Care Medicine, and Pain Medicine, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
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85
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Watanabe M, Zhang J, Mansuri MS, Duan J, Karimy JK, Delpire E, Alper SL, Lifton RP, Fukuda A, Kahle KT. Developmentally regulated KCC2 phosphorylation is essential for dynamic GABA-mediated inhibition and survival. Sci Signal 2019; 12:eaaw9315. [PMID: 31615901 PMCID: PMC7219477 DOI: 10.1126/scisignal.aaw9315] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Despite its importance for γ-aminobutyric acid (GABA) inhibition and involvement in neurodevelopmental disease, the regulatory mechanisms of the K+/Cl- cotransporter KCC2 (encoded by SLC12A5) during maturation of the central nervous system (CNS) are not entirely understood. Here, we applied quantitative phosphoproteomics to systematically map sites of KCC2 phosphorylation during CNS development in the mouse. KCC2 phosphorylation at Thr906 and Thr1007, which inhibits KCC2 activity, underwent dephosphorylation in parallel with the GABA excitatory-inhibitory sequence in vivo. Knockin mice expressing the homozygous phosphomimetic KCC2 mutations T906E/T1007E (Kcc2E/E ), which prevented the normal developmentally regulated dephosphorylation of these sites, exhibited early postnatal death from respiratory arrest and a marked absence of cervical spinal neuron respiratory discharges. Kcc2E/E mice also displayed disrupted lumbar spinal neuron locomotor rhythmogenesis and touch-evoked status epilepticus associated with markedly impaired KCC2-dependent Cl- extrusion. These data identify a previously unknown phosphorylation-dependent KCC2 regulatory mechanism during CNS development that is essential for dynamic GABA-mediated inhibition and survival.
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Affiliation(s)
- Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - M Shahid Mansuri
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06510, USA
| | - Jingjing Duan
- Human Aging Research Institute, School of Life Sciences, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Jason K Karimy
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06510, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Seth L Alper
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
- The Broad Institute of Harvard and the Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Richard P Lifton
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, NY, USA
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
- Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kristopher T Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular and Molecular Physiology, Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT 06510, USA.
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86
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Seifikalhor M, Aliniaeifard S, Hassani B, Niknam V, Lastochkina O. Diverse role of γ-aminobutyric acid in dynamic plant cell responses. PLANT CELL REPORTS 2019; 38:847-867. [PMID: 30739138 DOI: 10.1007/s00299-019-02396-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/02/2019] [Indexed: 05/05/2023]
Abstract
Gamma-aminobutyric acid (GABA), a four-carbon non-protein amino acid, is found in most prokaryotic and eukaryotic organisms. Although, ample research into GABA has occurred in mammals as it is a major inhibitory neurotransmitter; in plants, a role for GABA has often been suggested as a metabolite that changes under stress rather than as a signal, as no receptor or motif for GABA binding was identified until recently and many aspects of its biological function (ranging from perception to function) remain to be answered. In this review, flexible properties of GABA in regulation of plant responses to various environmental biotic and abiotic stresses and its integration in plant growth and development either as a metabolite or a signaling molecule are discussed. We have elaborated on the role of GABA in stress adaptation (i.e., salinity, hypoxia/anoxia, drought, temperature, heavy metals, plant-insect interplay and ROS-related responses) and its contribution in non-stress-related biological pathways (i.e., involvement in plant-microbe interaction, contribution to the carbon and nitrogen metabolism and governing of signal transduction pathways). This review aims to represent the multifunctional contribution of GABA in various biological and physiological mechanisms under stress conditions; the objective is to review the current state of knowledge about GABA role beyond stress-related responses. Our effort is to place findings about GABA in an organized and broader context to highlight its shared metabolic and biologic functions in plants under variable conditions. This will provide potential modes of GABA crosstalk in dynamic plant cell responses.
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Affiliation(s)
- Maryam Seifikalhor
- Department of Plant Biology, Center of Excellence in Phylogeny of Living Organisms in Iran, School of Biology, College of Science, University of Tehran, Tehran, 14155, Iran
| | - Sasan Aliniaeifard
- Department of Horticulture, College of Aburaihan, University of Tehran, Tehran, Iran.
| | - Batool Hassani
- Department of Plant Sciences, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Vahid Niknam
- Department of Plant Biology, Center of Excellence in Phylogeny of Living Organisms in Iran, School of Biology, College of Science, University of Tehran, Tehran, 14155, Iran
| | - Oksana Lastochkina
- Bashkir Research Institute of Agriculture, Russian Academy of Sciences, Ufa, Russia
- Institute of Biochemistry and Genetics, Russian Academy of Sciences, Ufa, Russia
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87
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Clyburn C, Howe CA, Arnold AC, Lang CH, Travagli RA, Browning KN. Perinatal high-fat diet alters development of GABA A receptor subunits in dorsal motor nucleus of vagus. Am J Physiol Gastrointest Liver Physiol 2019; 317:G40-G50. [PMID: 31042399 PMCID: PMC6689732 DOI: 10.1152/ajpgi.00079.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/22/2019] [Accepted: 04/29/2019] [Indexed: 01/31/2023]
Abstract
Perinatal high-fat diet (pHFD) exposure increases the inhibition of dorsal motor nucleus of the vagus (DMV) neurons, potentially contributing to the dysregulation of gastric functions. The aim of this study was to test the hypothesis that pHFD increases the inhibition of DMV neurons by disrupting GABAA receptor subunit development. In vivo gastric recordings were made from adult anesthetized Sprague-Dawley rats fed a control or pHFD (14 or 60% kcal from fat, respectively) from embryonic day 13 (E13) to postnatal day 42 (P42), and response to brainstem microinjection of benzodiazepines was assessed. Whole cell patch clamp recordings from DMV neurons assessed the functional expression of GABAA α subunits, whereas mRNA and protein expression were measured via qPCR and Western blotting, respectively. pHFD decreased basal antrum and corpus motility, whereas brainstem microinjection of L838,417 (positive allosteric modulator of α2/3 subunit-containing GABAA receptors) produced a larger decrease in gastric tone and motility. GABAergic miniature inhibitory postsynaptic currents in pHFD DMV neurons were responsive to L838,417 throughout development, unlike control DMV neurons, which were responsive only at early postnatal timepoints. Brainstem mRNA and protein expression of the GABAA α1,2, and 3 subunits, however, did not differ between control and pHFD rats. This study suggests that pHFD exposure arrests the development of synaptic GABAA α2/3 receptor subunits on DMV neurons and that functional synaptic expression is maintained into adulthood, although cellular localization may differ. The tonic activation of slower GABAA α2/3 subunit-containing receptors implies that such developmental changes may contribute to the observed decreased gastric motility. NEW & NOTEWORTHY Vagal neurocircuits involved in the control of gastric functions, satiation, and food intake are subject to significant developmental regulation postnatally, with immature GABAA receptors expressing slower α2/3-subunits, whereas mature GABAA receptor express faster α1-subunits. After perinatal high-fat diet exposure, this developmental regulation of dorsal motor nucleus of the vagus (DMV) neurons is disrupted, increasing their tonic GABAergic inhibition, decreasing efferent output, and potentially decreasing gastric motility.
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Affiliation(s)
- Courtney Clyburn
- Department of Neural and Behavioral Sciences, Penn State College of Medicine , Hershey, Pennsylvania
| | - Caitlin A Howe
- Department of Neural and Behavioral Sciences, Penn State College of Medicine , Hershey, Pennsylvania
| | - Amy C Arnold
- Department of Neural and Behavioral Sciences, Penn State College of Medicine , Hershey, Pennsylvania
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine , Hershey, Pennsylvania
| | - R Alberto Travagli
- Department of Neural and Behavioral Sciences, Penn State College of Medicine , Hershey, Pennsylvania
| | - Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State College of Medicine , Hershey, Pennsylvania
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88
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Xu J, Xu M, Wang Y, Mathena RP, Wen J, Zhang P, Furmanski O, Mintz CD. Anesthetics disrupt growth cone guidance cue sensing through actions on the GABA A α2 receptor mediated by the immature chloride gradient. Neurotoxicol Teratol 2019; 74:106812. [PMID: 31251980 DOI: 10.1016/j.ntt.2019.106812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/25/2019] [Accepted: 06/24/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND General anesthetics (GAs) may exert harmful effects on the developing brain by disrupting neuronal circuit formation. Anesthetics that act on γ-aminobutyric acid (GABA) receptors can interfere with axonal growth cone guidance, a critical process in the assembly of neuronal circuitry. Here we investigate the mechanism by which isoflurane prevents sensing of the repulsive guidance cue, Semaphorin 3A (Sema3A). METHODS Growth cone sensing was assayed by measuring growth cone collapse in dissociated neocortical cultures exposed to recombinant Sema3A in the presence or absence of isoflurane and/or a panel of reagents with specific actions on components of the GABA receptor and chloride ion systems. RESULTS Isoflurane exposure prevents Sema3A induced growth cone collapse. A GABAA α2 specific agonist replicates this effect (36.83 ± 3.417% vs 70.82 ± 2.941%, in the Sema3A induced control group, p < 0.0001), but an α1-specific agonist does not. Both a Na-K-Cl cotransporter 1 antagonism (bumetanide, BUM) and a chloride ionophore (IONO) prevent isoflurane from disrupting growth cone sensing of Sema3A. (65.67 ± 3.775% in Iso + BUM group vs 67.45 ± 3.624% in Sema3A induced control group, 65.34 ± 1.678% in Iso + IONO group vs 68.71 ± 2.071% in Sema3A induced control group, no significant difference) (n = 96 growth cones per group). CONCLUSION Our data suggest that the effects of isoflurane on growth cone sensing are mediated by the α2 subunit of the GABAA receptor and also that they are dependent on the developmental chloride gradient, in which Cl- exhibits a depolarizing effect. These findings provide a rationale for why immature neurons are particularly susceptible to anesthetic toxicity.
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Affiliation(s)
- Jing Xu
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, 710004, China; Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael Xu
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - YuChia Wang
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - R Paige Mathena
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jieqiong Wen
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, 710004, China; Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pengbo Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, 710004, China
| | - Orion Furmanski
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - C David Mintz
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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89
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Tyrosine phosphorylation modulates cell surface expression of chloride cotransporters NKCC2 and KCC3. Arch Biochem Biophys 2019; 669:61-70. [PMID: 31145900 DOI: 10.1016/j.abb.2019.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 11/22/2022]
Abstract
Cellular chloride transport has a fundamental role in cell volume regulation and renal salt handling. Cellular chloride entry or exit are mediated at the plasma membrane by cotransporter proteins of the solute carrier 12 family. For example, NKCC2 resorbs chloride with sodium and potassium ions at the apical membrane of epithelial cells in the kidney, whereas KCC3 releases chloride with potassium ions at the basolateral membrane. Their ion transport activity is regulated by protein phosphorylation in response to signaling pathways. An additional regulatory mechanism concerns the amount of cotransporter molecules inserted into the plasma membrane. Here we describe that tyrosine phosphorylation of NKCC2 and KCC3 regulates their plasma membrane expression levels. We identified that spleen tyrosine kinase (SYK) phosphorylates a specific N-terminal tyrosine residue in each cotransporter. Experimental depletion of endogenous SYK or pharmacological inhibition of its kinase activity increased the abundance of NKCC2 at the plasma membrane of human embryonic kidney cells. In contrast, overexpression of a constitutively active SYK mutant decreased NKCC2 membrane abundance. Intriguingly, the same experimental approaches revealed the opposite effect on KCC3 abundance at the plasma membrane, compatible with the known antagonistic roles of NKCC and KCC cotransporters in cell volume regulation. Thus, we identified a novel pathway modulating the cell surface expression of NKCC2 and KCC3 and show that this same pathway has opposite functional outcomes for these two cotransporters. The findings have several biomedical implications considering the role of these cotransporters in regulating blood pressure and cell volume.
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90
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Nakamura K, Moorhouse AJ, Cheung DL, Eto K, Takeda I, Rozenbroek PW, Nabekura J. Overexpression of neuronal K +-Cl - co-transporter enhances dendritic spine plasticity and motor learning. J Physiol Sci 2019; 69:453-463. [PMID: 30758780 PMCID: PMC10717839 DOI: 10.1007/s12576-018-00654-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 12/17/2018] [Indexed: 11/30/2022]
Abstract
The neuronal K+-Cl- cotransporter KCC2 maintains a low intracellular Cl- concentration and facilitates hyperpolarizing GABAA receptor responses. KCC2 also plays a separate role in stabilizing and enhancing dendritic spines in the developing nervous system. Using a conditional transgenic mouse strategy, we examined whether overexpression of KCC2 enhances dendritic spines in the adult nervous system and characterized the effects on spine dynamics in the motor cortex in vivo during rotarod training. Mice overexpressing KCC2 showed significantly increased spine density in the apical dendrites of layer V pyramidal neurons, measured in vivo using two-photon imaging. During modest accelerated rotarod training, mice overexpressing KCC2 displayed enhanced spine formation rates, greater balancing skill at higher rotarod speeds and a faster rate of learning in this ability. Our results demonstrate that KCC2 enhances spine density and dynamics in the adult nervous system and suggest that KCC2 may play a role in experience-dependent synaptic plasticity.
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Affiliation(s)
- Kayo Nakamura
- Division of Homeostatic Development, Department of Fundamental Neuroscience, National Institutes for Physiological Sciences, Okazaki, 444-8585, Japan
- Department of Physiological Sciences, Sokendai, Hayama, 240-0193, Japan
| | - Andrew John Moorhouse
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Dennis Lawrence Cheung
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Kei Eto
- Division of Homeostatic Development, Department of Fundamental Neuroscience, National Institutes for Physiological Sciences, Okazaki, 444-8585, Japan
| | - Ikuko Takeda
- Division of Homeostatic Development, Department of Fundamental Neuroscience, National Institutes for Physiological Sciences, Okazaki, 444-8585, Japan
| | - Paul Wiers Rozenbroek
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Junichi Nabekura
- Division of Homeostatic Development, Department of Fundamental Neuroscience, National Institutes for Physiological Sciences, Okazaki, 444-8585, Japan.
- Department of Physiological Sciences, Sokendai, Hayama, 240-0193, Japan.
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91
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Brandenburg JE, Fogarty MJ, Sieck GC. A Critical Evaluation of Current Concepts in Cerebral Palsy. Physiology (Bethesda) 2019; 34:216-229. [PMID: 30968751 PMCID: PMC7938766 DOI: 10.1152/physiol.00054.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/11/2019] [Accepted: 01/23/2019] [Indexed: 11/22/2022] Open
Abstract
Spastic cerebral palsy (CP), despite the name, is not consistently identifiable by specific brain lesions. CP animal models focus on risk factors for development of CP, yet few reproduce the diagnostic symptoms. Animal models of CP must advance beyond risk factors to etiologies, including both the brain and spinal cord.
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Affiliation(s)
- Joline E Brandenburg
- Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine , Rochester, Minnesota
- Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Matthew J Fogarty
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Gary C Sieck
- Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine , Rochester, Minnesota
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine , Rochester, Minnesota
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
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92
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Kharod SC, Kang SK, Kadam SD. Off-Label Use of Bumetanide for Brain Disorders: An Overview. Front Neurosci 2019; 13:310. [PMID: 31068771 PMCID: PMC6491514 DOI: 10.3389/fnins.2019.00310] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 01/17/2023] Open
Abstract
Bumetanide (BTN or BUM) is a FDA-approved potent loop diuretic (LD) that acts by antagonizing sodium-potassium-chloride (Na-K-Cl) cotransporters, NKCC1 (SLc12a2) and NKCC2. While NKCC1 is expressed both in the CNS and in systemic organs, NKCC2 is kidney-specific. The off-label use of BTN to modulate neuronal transmembrane Cl− gradients by blocking NKCC1 in the CNS has now been tested as an anti-seizure agent and as an intervention for neurological disorders in pre-clinical studies with varying results. BTN safety and efficacy for its off-label use has also been tested in several clinical trials for neonates, children, adolescents, and adults. It failed to meet efficacy criteria for hypoxic-ischemic encephalopathy (HIE) neonatal seizures. In contrast, positive outcomes in temporal lobe epilepsy (TLE), autism, and schizophrenia trials have been attributed to BTN in studies evaluating its off-label use. NKCC1 is an electroneutral neuronal Cl− importer and the dominance of NKCC1 function has been proposed as the common pathology for HIE seizures, TLE, autism, and schizophrenia. Therefore, the use of BTN to antagonize neuronal NKCC1 with the goal to lower internal Cl− levels and promote GABAergic mediated hyperpolarization has been proposed. In this review, we summarize the data and results for pre-clinical and clinical studies that have tested off-label BTN interventions and report variable outcomes. We also compare the data underlying the developmental expression profile of NKCC1 and KCC2, highlight the limitations of BTN’s brain-availability and consider its actions on non-neuronal cells.
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Affiliation(s)
- Shivani C Kharod
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Seok Kyu Kang
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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93
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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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94
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Sasaki Russell JM, Chinn GA, Maharjan D, Eichbaum Y, Sall JW. Female rats are more vulnerable to lasting cognitive impairment after isoflurane exposure on postnatal day 4 than 7. Br J Anaesth 2019; 122:490-499. [PMID: 30857605 PMCID: PMC6435941 DOI: 10.1016/j.bja.2018.12.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 11/16/2018] [Accepted: 12/05/2018] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The factors determining peak susceptibility of the developing brain to anaesthetics are unclear. It is unknown why postnatal day 7 (P7) male rats are more vulnerable to anaesthesia-induced memory deficits than littermate females. Given the precocious development of certain regions in the female brain during the neonatal critical period, we hypothesised that females are susceptible to anaesthetic brain injury at an earlier time point than previously tested. METHODS Female rats were exposed to isoflurane (Iso) 1 minimum alveolar concentration or sham anaesthesia at P4 or P7. Starting at P35, rats underwent a series of behavioural tasks to test their spatial and recognition memory. Cell death immediately after anaesthesia was quantified by Fluoro-Jade C staining in select brain regions, and developmental expression of the chloride transporters KCC2 and NKCC1 was analysed by immunoblotting in male and female rats at P4 and P7. RESULTS Female rats exposed to Iso at P4 displayed impaired spatial, object-place, -context, and social recognition memory, and increased cell death in the hippocampus and laterodorsal thalamus. Female rats exposed at P7 exhibited only decreased performance in object-context compared with control. The ratio of NKCC1/KCC2 expression in cerebral cortex was higher in P4 females than in P7 females, and similar to that in P7 males. CONCLUSIONS Female rats exposed to Iso at P4 are sensitive to anaesthetic injury historically observed in P7 males. This is consistent with a comparably immature developmental state in P4 females and P7 males. The window of anaesthetic vulnerability correlates with sex-specific cortical expression of chloride transporters NKCC1 and KCC2. These findings suggest that both sex and developmental age play important roles in determining the outcome after early anaesthesia exposure.
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Affiliation(s)
| | - Gregory A Chinn
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
| | - Deenu Maharjan
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
| | - Yasmine Eichbaum
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA
| | - Jeffrey W Sall
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, USA.
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95
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Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
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Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
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96
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Côme E, Marques X, Poncer JC, Lévi S. KCC2 membrane diffusion tunes neuronal chloride homeostasis. Neuropharmacology 2019; 169:107571. [PMID: 30871970 DOI: 10.1016/j.neuropharm.2019.03.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 02/26/2019] [Accepted: 03/10/2019] [Indexed: 02/05/2023]
Abstract
Neuronal Cl- homeostasis is regulated by the activity of two cation chloride co-transporters (CCCs), the K+-Cl- cotransporter KCC2 and the Na+-K+-Cl- cotransporter NKCC1, which are primarily extruding and importing chloride in neurons, respectively. Several neurological and psychiatric disorders including epilepsy, neuropathic pain, schizophrenia and autism are associated with altered neuronal chloride (Cl-) homeostasis. A current view is that the accumulation of intracellular Cl- in neurons as a result of KCC2 down-regulation and/or NKCC1 up-regulation may weaken inhibitory GABA signaling and thereby promote the development of pathological activities. CCC activity is determined mainly by their level of expression in the plasma membrane. Furthermore, CCCs undergo "diffusion-trapping" in the membrane, a mechanism that is rapidly adjusted by activity-dependent post-translational modifications i.e. phosphorylation/dephosphorylation of key serine and threonine residues. This represents probably the most rapid cellular mechanism for adapting CCC function to changes in neuronal activity. Therefore, interfering with these mechanisms may help restoring Cl- homeostasis and inhibition under pathological conditions. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.
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Affiliation(s)
- Etienne Côme
- INSERM UMR-S 1270, 75005, Paris, France; Sorbonne Université, 75005, Paris, France; Institut du Fer à Moulin, 75005, Paris, France
| | - Xavier Marques
- INSERM UMR-S 1270, 75005, Paris, France; Sorbonne Université, 75005, Paris, France; Institut du Fer à Moulin, 75005, Paris, France
| | - Jean Christophe Poncer
- INSERM UMR-S 1270, 75005, Paris, France; Sorbonne Université, 75005, Paris, France; Institut du Fer à Moulin, 75005, Paris, France
| | - Sabine Lévi
- INSERM UMR-S 1270, 75005, Paris, France; Sorbonne Université, 75005, Paris, France; Institut du Fer à Moulin, 75005, Paris, France.
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97
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Mele M, Costa RO, Duarte CB. Alterations in GABA A-Receptor Trafficking and Synaptic Dysfunction in Brain Disorders. Front Cell Neurosci 2019; 13:77. [PMID: 30899215 PMCID: PMC6416223 DOI: 10.3389/fncel.2019.00077] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/15/2019] [Indexed: 12/12/2022] Open
Abstract
GABAA receptors (GABAAR) are the major players in fast inhibitory neurotransmission in the central nervous system (CNS). Regulation of GABAAR trafficking and the control of their surface expression play important roles in the modulation of the strength of synaptic inhibition. Different pieces of evidence show that alterations in the surface distribution of GABAAR and dysregulation of their turnover impair the activity of inhibitory synapses. A diminished efficacy of inhibitory neurotransmission affects the excitatory/inhibitory balance and is a common feature of various disorders of the CNS characterized by an increased excitability of neuronal networks. The synaptic pool of GABAAR is mainly controlled through regulation of internalization, recycling and lateral diffusion of the receptors. Under physiological condition these mechanisms are finely coordinated to define the strength of GABAergic synapses. In this review article, we focus on the alteration in GABAAR trafficking with an impact on the function of inhibitory synapses in various disorders of the CNS. In particular we discuss how similar molecular mechanisms affecting the synaptic distribution of GABAAR and consequently the excitatory/inhibitory balance may be associated with a wide diversity of pathologies of the CNS, from psychiatric disorders to acute alterations leading to neuronal death. A better understanding of the cellular and molecular mechanisms that contribute to the impairment of GABAergic neurotransmission in these disorders, in particular the alterations in GABAAR trafficking and surface distribution, may lead to the identification of new pharmacological targets and to the development of novel therapeutic strategies.
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Affiliation(s)
- Miranda Mele
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Rui O Costa
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, 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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98
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Allen LL, Seven YB, Baker TL, Mitchell GS. Cervical spinal contusion alters Na +-K +-2Cl- and K +-Cl- cation-chloride cotransporter expression in phrenic motor neurons. Respir Physiol Neurobiol 2019; 261:15-23. [PMID: 30590202 PMCID: PMC6939623 DOI: 10.1016/j.resp.2018.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 12/21/2018] [Accepted: 12/23/2018] [Indexed: 12/11/2022]
Abstract
Spinal chloride-dependent synaptic inhibition is critical in regulating breathing and requires neuronal chloride gradients established by cation-chloride cotransporters Na+-K+-2Cl- (NKCC1) and K+-Cl- (KCC2). Spinal transection disrupts NKCC1/KCC2 balance, diminishing chloride gradients in neurons below injury, contributing to spasticity and chronic pain. It is not known if similar disruptions in NKCC1/KCC2 balance occur in respiratory motor neurons after incomplete cervical contusion (C2SC). We hypothesized that C2SC disrupts NKCC1/KCC2 balance in phrenic motor neurons. NKCC1 and KCC2 immunoreactivity was assessed in CtB-positive phrenic motor neurons. Five weeks post-C2SC: 1) neither membrane-bound nor cytosolic NKCC1 expression were significantly changed, although the membrane/cytosolic ratio increased, consistent with net chloride influx; and 2) both membrane and cytosolic KCC2 expression increased, although the membrane/cytosolic ratio decreased, consistent with net chloride efflux. Thus, contrary to our original hypothesis, complex shifts in NKCC1/KCC2 balance occur post-C2SC. The functional significance of these changes remains unclear.
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Affiliation(s)
- Latoya L Allen
- Department of Physical Therapy, University of Florida, Gainesville, FL 32611 USA; Department of Neuroscience, University of Florida, Gainesville, FL 32610 USA; Center for Respiratory Research and Rehabilitation, University of Florida, Gainesville, FL 32611 USA
| | - Yasin B Seven
- Department of Physical Therapy, University of Florida, Gainesville, FL 32611 USA; Center for Respiratory Research and Rehabilitation, University of Florida, Gainesville, FL 32611 USA
| | - Tracy L Baker
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Gordon S Mitchell
- Department of Physical Therapy, University of Florida, Gainesville, FL 32611 USA; Center for Respiratory Research and Rehabilitation, University of Florida, Gainesville, FL 32611 USA.
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99
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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: 25] [Impact Index Per Article: 5.0] [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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100
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Genç F, Kara M, Ünal Y, Uygur Küçükseymen E, Biçer Gömceli Y, Kaynar T, Tosun K, Kutlu G. Methylation of cation-chloride cotransporters NKCC1 and KCC2 in patients with juvenile myoclonic epilepsy. Neurol Sci 2019; 40:1007-1013. [PMID: 30759289 DOI: 10.1007/s10072-019-03743-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/30/2019] [Indexed: 10/27/2022]
Abstract
The etiology of juvenile myoclonic epilepsy (JME) is still unknown and the process of elaboration of multiple genetic mechanisms is ongoing. The aim of this study was to investigate the potential role of NKCC1 (SCL12A2) and KCC2 (SCL12A5) in JME by comparing their DNA methylation status in patients with JME versus healthy controls. Forty-nine patients with JME and 39 healthy individuals were compared for DNA methylation at the 5CpG islands. A total of 71 (81%) samples were found to have methylation in the NKCC1 gene, 36 (73%) from patients and 35 (90%) from healthy individuals. Out of the KCC2 samples, 50 (57%) were found to have methylation, 33 (67%) from patients and 17 (44%) from healthy individuals. In patients with JME, methylation of NKCC1 (73%) was lower than its methylation in the controls (90%) (p = 0.047). On the other hand, methylation of KCC2 in patients with JME (67%) was greater than the methylation in the controls (44%) (p = 0.022). Twenty-eight patients were treated with VPA and ongoing medications were not found to be associated with methylation (p > 0.05). In the present study, we determined significantly lower NKCC1 DNA methylation and significantly higher KCC2 DNA methylation levels in patients with JME compared with the healthy controls. This implies that NKCC1 expression can be higher and KCC2 expression can be reduced in affected people. Further studies that investigate the potential effect of DNA methylation mechanisms regulating gene expression on seizure activity and how they change JME network activity will be helpful.
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Affiliation(s)
- Fatma Genç
- Antalya Training and Research Hospital, Department of Neurology, Antalya, Turkey.
| | | | - Yasemin Ünal
- Faculty of Medicine Department of Neurology, Muğla Sıtkı Koçman University, Muğla, Turkey
| | - Elif Uygur Küçükseymen
- Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Taner Kaynar
- Sitogen Biomedical and Laboratory Systems Industrial Trade Limited Company, Zümrütevler mah. Hanımeli cad. Aktunç İşmerkezi No:13/1 Maltepe, İstanbul, Turkey
| | | | - Gülnihal Kutlu
- Faculty of Medicine Department of Neurology and Clinical Neurophysiology, Muğla Sıtkı Koçman University, Muğla, Turkey
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