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Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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2
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Furukawa T, Fukuda A. Maternal taurine as a modulator of Cl - homeostasis as well as of glycine/GABA A receptors for neocortical development. Front Cell Neurosci 2023; 17:1221441. [PMID: 37601283 PMCID: PMC10435090 DOI: 10.3389/fncel.2023.1221441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/20/2023] [Indexed: 08/22/2023] Open
Abstract
During brain and spinal cord development, GABA and glycine, the inhibitory neurotransmitters, cause depolarization instead of hyperpolarization in adults. Since glycine and GABAA receptors (GABAARs) are chloride (Cl-) ion channel receptor, the conversion of GABA/glycine actions during development is influenced by changes in the transmembrane Cl- gradient, which is regulated by Cl- transporters, NKCC1 (absorption) and KCC2 (expulsion). In immature neurons, inhibitory neurotransmitters are released in a non-vesicular/non-synaptic manner, transitioning to vesicular/synaptic release as the neuron matures. In other word, in immature neurons, neurotransmitters generally act tonically. Thus, the glycine/GABA system is a developmentally multimodal system that is required for neurogenesis, differentiation, migration, and synaptogenesis. The endogenous agonists for these receptors are not fully understood, we address taurine. In this review, we will discuss about the properties and function of taurine during development of neocortex. Taurine cannot be synthesized by fetuses or neonates, and is transferred from maternal blood through the placenta or maternal milk ingestion. In developing neocortex, taurine level is higher than GABA level, and taurine tonically activates GABAARs to control radial migration as a stop signal. In the marginal zone (MZ) of the developing neocortex, endogenous taurine modulates the spread of excitatory synaptic transmission, activating glycine receptors (GlyRs) as an endogenous agonist. Thus, taurine affects information processing and crucial developmental processes such as axonal growth, cell migration, and lamination in the developing cerebral cortex. Additionally, we also refer to the possible mechanism of taurine-regulating Cl- homeostasis. External taurine is uptake by taurine transporter (TauT) and regulates NKCC1 and KCC2 mediated by intracellular signaling pathway, with-no-lysine kinase 1 (WNK1) and its subsequent kinases STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) and oxidative stress response kinase-1 (OSR1). Through the regulation of NKCC1 and KCC2, mediated by the WNK-SPAK/OSR1 signaling pathway, taurine plays a role in maintaining Cl- homeostasis during normal brain development.
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Affiliation(s)
- Tomonori Furukawa
- Department of Neurophysiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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3
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Pajer K, Bellák T, Grósz T, Nógrádi B, Patai R, Sinkó J, Vinay L, Liabeuf S, Erdélyi M, Nógrádi A. Riluzole treatment modulates KCC2 and EAAT-2 receptor expression and Ca 2+ accumulation following ventral root avulsion injury. Eur J Cell Biol 2023; 102:151317. [PMID: 37099936 DOI: 10.1016/j.ejcb.2023.151317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 04/28/2023] Open
Abstract
Avulsion injury results in motoneuron death due to the increased excitotoxicity developing in the affected spinal segments. This study focused on possible short and long term molecular and receptor expression alterations which are thought to be linked to the excitotoxic events in the ventral horn with or without the anti-excitotoxic riluzole treatment. In our experimental model the left lumbar 4 and 5 (L4, 5) ventral roots of the spinal cord were avulsed. Treated animals received riluzole for 2 weeks. Riluzole is a compound that acts to block voltage-activated Na+ and Ca2+ channels. In control animals the L4, 5 ventral roots were avulsed without riluzole treatment. Expression of astrocytic EAAT-2 and that of KCC2 in motoneurons on the affected side of the L4 spinal segment were detected after the injury by confocal and dSTORM imaging, intracellular Ca2+ levels in motoneurons were quantified by electron microscopy. The KCC2 labeling in the lateral and ventrolateral parts of the L4 ventral horn was weaker compared with the medial part of L4 ventral horn in both groups. Riluzole treatment dramatically enhanced motoneuron survival but was not able to prevent the down-regulation of KCC2 expression in injured motoneurons. In contrast, riluzole successfully obviated the increase of intracellular calcium level and the decrease of EAAT-2 expression in astrocytes compared with untreated injured animals. We conclude that KCC2 may not be an essential component for survival of injured motoneurons and riluzole is able to modulate the intracellular level of calcium and expression of EAAT-2.
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Affiliation(s)
- Krisztián Pajer
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Tamás Bellák
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Tímea Grósz
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bernát Nógrádi
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary; Department of Neurology, Albert Szent-Györgyi Health Center, University of Szeged, Szeged, Hungary
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - József Sinkó
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Laurent Vinay
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, Campus Santé Timone, 13385 Marseille, France
| | - Sylvie Liabeuf
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, Campus Santé Timone, 13385 Marseille, France
| | - Miklós Erdélyi
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Antal Nógrádi
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary.
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Hartmann AM, Nothwang HG. NKCC1 and KCC2: Structural insights into phospho-regulation. Front Mol Neurosci 2022; 15:964488. [PMID: 35935337 PMCID: PMC9355526 DOI: 10.3389/fnmol.2022.964488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory neurotransmission plays a fundamental role in the central nervous system, with about 30–50% of synaptic connections being inhibitory. The action of both inhibitory neurotransmitter, gamma-aminobutyric-acid (GABA) and glycine, mainly relies on the intracellular Cl– concentration in neurons. This is set by the interplay of the cation chloride cotransporters NKCC1 (Na+, K+, Cl– cotransporter), a main Cl– uptake transporter, and KCC2 (K+, Cl– cotransporter), the principle Cl– extruder in neurons. Accordingly, their dysfunction is associated with severe neurological, psychiatric, and neurodegenerative disorders. This has triggered great interest in understanding their regulation, with a strong focus on phosphorylation. Recent structural data by cryogenic electron microscopy provide the unique possibility to gain insight into the action of these phosphorylations. Interestingly, in KCC2, six out of ten (60%) known regulatory phospho-sites reside within a region of 134 amino acid residues (12% of the total residues) between helices α8 and α9 that lacks fixed or ordered three-dimensional structures. It thus represents a so-called intrinsically disordered region. Two further phospho-sites, Tyr903 and Thr906, are also located in a disordered region between the ß8 strand and the α8 helix. We make the case that especially the disordered region between helices α8 and α9 acts as a platform to integrate different signaling pathways and simultaneously constitute a flexible, highly dynamic linker that can survey a wide variety of distinct conformations. As each conformation can have distinct binding affinities and specificity properties, this enables regulation of [Cl–]i and thus the ionic driving force in a history-dependent way. This region might thus act as a molecular processor underlying the well described phenomenon of ionic plasticity that has been ascribed to inhibitory neurotransmission. Finally, it might explain the stunning long-range effects of mutations on phospho-sites in KCC2.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- *Correspondence: Anna-Maria Hartmann,
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Hui KK, Chater TE, Goda Y, Tanaka M. How Staying Negative Is Good for the (Adult) Brain: Maintaining Chloride Homeostasis and the GABA-Shift in Neurological Disorders. Front Mol Neurosci 2022; 15:893111. [PMID: 35875665 PMCID: PMC9305173 DOI: 10.3389/fnmol.2022.893111] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023] Open
Abstract
Excitatory-inhibitory (E-I) imbalance has been shown to contribute to the pathogenesis of a wide range of neurodevelopmental disorders including autism spectrum disorders, epilepsy, and schizophrenia. GABA neurotransmission, the principal inhibitory signal in the mature brain, is critically coupled to proper regulation of chloride homeostasis. During brain maturation, changes in the transport of chloride ions across neuronal cell membranes act to gradually change the majority of GABA signaling from excitatory to inhibitory for neuronal activation, and dysregulation of this GABA-shift likely contributes to multiple neurodevelopmental abnormalities that are associated with circuit dysfunction. Whilst traditionally viewed as a phenomenon which occurs during brain development, recent evidence suggests that this GABA-shift may also be involved in neuropsychiatric disorders due to the “dematuration” of affected neurons. In this review, we will discuss the cell signaling and regulatory mechanisms underlying the GABA-shift phenomenon in the context of the latest findings in the field, in particular the role of chloride cotransporters NKCC1 and KCC2, and furthermore how these regulatory processes are altered in neurodevelopmental and neuropsychiatric disorders. We will also explore the interactions between GABAergic interneurons and other cell types in the developing brain that may influence the GABA-shift. Finally, with a greater understanding of how the GABA-shift is altered in pathological conditions, we will briefly outline recent progress on targeting NKCC1 and KCC2 as a therapeutic strategy against neurodevelopmental and neuropsychiatric disorders associated with improper chloride homeostasis and GABA-shift abnormalities.
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Affiliation(s)
- Kelvin K. Hui
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY, United States
- *Correspondence: Kelvin K. Hui,
| | - Thomas E. Chater
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Thomas E. Chater,
| | - Yukiko Goda
- Laboratory for Synaptic Plasticity and Connectivity, RIKEN Center for Brain Science, Wako, Japan
- Synapse Biology Unit, Okinawa Institute for Science and Technology Graduate University, Onna, Japan
| | - Motomasa Tanaka
- Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Japan
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Chen L, Yu J, Wan L, Wu Z, Wang G, Hu Z, Ren L, Zhou J, Qian B, Zhao X, Zhang J, Liu X, Wang Y. Furosemide prevents membrane KCC2 downregulation during convulsant stimulation in the hippocampus. IBRO Neurosci Rep 2022; 12:355-365. [PMID: 35746976 PMCID: PMC9210493 DOI: 10.1016/j.ibneur.2022.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/15/2022] [Accepted: 04/25/2022] [Indexed: 02/08/2023] Open
Abstract
In adults, γ-aminobutyric acid (GABA) type A receptor (GABAAR)-mediated inhibition depends on the maintenance of low intracellular chloride anion concentration through neuron-specific potassium-chloride cotransporter-2 (KCC2). KCC2 has been widely reported to have a plasticity change during the course of epilepsy development, with an early downregulation and late recovery in neuronal cell membranes after epileptic stimulation, which facilitates epileptiform burst activity. Furosemide is a clinical loop diuretic that inhibits KCC2. Here, we first confirmed that furosemide pretreatment could effectively prevented convulsant stimulation-induced neuronal membrane KCC2 downregulation in the hippocampus in both in vivo and in vitro cyclothiazide-induced seizure model. Second, we verified that furosemide pretreatment rescued KCC2 function deficits, as indicated by E GABA depolarizing shift and GABAAR inhibitory function impairment induced via cyclothiazide treatment. Further, we demonstrated that furosemide also suppressed cyclothiazide-induced epileptiform burst activity in cultured hippocampal neurons and lowered the mortality rate during acute seizure induction. Overall, furosemide prevents membrane KCC2 downregulation during acute seizure induction, restores KCC2-mediated GABA inhibition, and interrupts the progression from acute seizure to epileptogenesis.
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Affiliation(s)
- Lulan Chen
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jiangning Yu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Li Wan
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Zheng Wu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Guoxiang Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zihan Hu
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liang Ren
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Binbin Qian
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xuan Zhao
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Correspondence to: Department of Anesthesiology, Shanghai Tenth People’s Hospital, China.
| | - Jinwei Zhang
- Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - Xu Liu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Correspondence to: Department of Neurology, Zhongshan Hospital, Fudan University, China.
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
- Correspondence to: Institutes of Brain Science, Fudan University, Shanghai 200032, China.
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7
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Structural basis for inhibition of the Cation-chloride cotransporter NKCC1 by the diuretic drug bumetanide. Nat Commun 2022; 13:2747. [PMID: 35585053 PMCID: PMC9117670 DOI: 10.1038/s41467-022-30407-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/28/2022] [Indexed: 11/08/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) NKCC1 and NKCC2 catalyze electroneutral symport of 1 Na+, 1 K+, and 2 Cl− across cell membranes. NKCC1 mediates trans-epithelial Cl− secretion and regulates excitability of some neurons and NKCC2 is critical to renal salt reabsorption. Both transporters are inhibited by the so-called loop diuretics including bumetanide, and these drugs are a mainstay for treating edema and hypertension. Here, our single-particle electron cryo-microscopy structures supported by functional studies reveal an outward-facing conformation of NKCC1, showing bumetanide wedged into a pocket in the extracellular ion translocation pathway. Based on these and the previously published inward-facing structures, we define the translocation pathway and the conformational changes necessary for ion translocation. We also identify an NKCC1 dimer with separated transmembrane domains and extensive transmembrane and C-terminal domain interactions. We further define an N-terminal phosphoregulatory domain that interacts with the C-terminal domain, suggesting a mechanism whereby (de)phosphorylation regulates NKCC1 by tuning the strength of this domain association. Loop diuretics including bumetanide inhibit Na+-K+-Cl−-cotransporters (NKCCs) and are used for the treatment of edema and hypertension. Here, Zhao et. al. report structures of NKCC1 with bumetanide bound, revealing its mechanism of action that would facilitate design of novel diuretics.
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Lee KG, Rajakumar N. Partial ablation of frontal cortical subplate leads to developmental abnormalities in KCC2 in the prefrontal cortex. Mol Cell Neurosci 2022; 120:103733. [DOI: 10.1016/j.mcn.2022.103733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 04/20/2022] [Accepted: 04/23/2022] [Indexed: 10/18/2022] Open
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9
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Shen Q, Wu X, Zhang Z, Zhang D, Yang S, Xing D. Gamma frequency light flicker regulates amyloid precursor protein trafficking for reducing β-amyloid load in Alzheimer's disease model. Aging Cell 2022; 21:e13573. [PMID: 35199454 PMCID: PMC8920449 DOI: 10.1111/acel.13573] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 01/05/2022] [Accepted: 02/02/2022] [Indexed: 11/28/2022] Open
Abstract
Inducing gamma oscillations with non‐invasive light flicker has been reported to impact Alzheimer's disease‐related pathology. However, it is unclear which signaling pathways are involved in reducing amyloid load. Here, we found that gamma frequency light flicker increased anchoring of amyloid precursor protein (APP) to the plasma membrane for non‐amyloidogenic processing, and then physically interacted with KCC2, a neuron‐specific K+‐Cl− cotransporter, suggesting that it is essential to maintain surface GABAA receptor α1 levels and reduce β‐amyloid (Aβ) production. Stimulation with such light flicker limited KCC2 internalization and subsequent degradation via both tyrosine phosphorylation and ubiquitination, leading to an increase in surface‐KCC2 levels. Specifically, PKC‐dependent phosphorylation of APP on a serine residue was induced by gamma frequency light flicker, which was responsible for maintaining plasma membrane levels of full‐length APP, leading to its reduced trafficking to endosomes and inhibiting the β‐secretase cleavage pathway. The activated PKC from the gamma frequency light flicker subsequently phosphorylated serine of KCC2 and stabilized it onto the cell surface, which contributed to the upregulation of surface GABAA receptor α1 levels. Together, these data indicate that enhancement of APP trafficking to the plasma membrane via light flicker plays a critical modulatory role in reduction of Aβ load in Alzheimer's disease.
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Affiliation(s)
- Qi Shen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
| | - Xiaolei Wu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
| | - Zhan Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
| | - Di Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
| | - Sihua Yang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
| | - Da Xing
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou China
- College of Biophotonics South China Normal University Guangzhou China
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10
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Okumo T, Takayama Y, Maruyama K, Kato M, Sunagawa M. Senso-Immunologic Prospects for Complex Regional Pain Syndrome Treatment. Front Immunol 2022; 12:786511. [PMID: 35069559 PMCID: PMC8767061 DOI: 10.3389/fimmu.2021.786511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/13/2021] [Indexed: 12/14/2022] Open
Abstract
Complex regional pain syndrome (CRPS) is a chronic pain syndrome that occurs in tissue injuries as the result of surgery, trauma, or ischemia. The clinical features of this severely painful condition include redness and swelling of the affected skin. Intriguingly, it was recently suggested that transient receptor potential ankyrin 1 (TRPA1) is involved in chronic post-ischemia pain, a CRPS model. TRPA1 is a non-selective cation channel expressed in calcitonin gene-related peptide (CGRP)-positive primary nociceptors that becomes highly activated in ischemic conditions, leading to the generation of pain. In this review, we summarize the history of TRPA1 and its involvement in pain sensation, inflammation, and CRPS. Furthermore, bone atrophy is also thought to be a characteristic clinical sign of CRPS. The altered bone microstructure of CRPS patients is thought to be caused by aggravated bone resorption via enhanced osteoclast differentiation and activation. Although TRPA1 could be a target for pain treatment in CRPS patients, we also discuss the paradoxical situation in this review. Nociceptor activation decreases the risk of bone destruction via CGRP secretion from free nerve endings. Thus, TRPA1 inhibition could cause severe bone atrophy. However, the suitable therapeutic strategy is controversial because the pathologic mechanisms of bone atrophy in CRPS are unclear. Therefore, we propose focusing on the remission of abnormal bone turnover observed in CRPS using a recently developed concept: senso-immunology.
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Affiliation(s)
- Takayuki Okumo
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
| | - Yasunori Takayama
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
| | - Kenta Maruyama
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan.,Division of Cell Signaling, National Institute for Physiological Sciences, Natural Institutes for Natural Sciences, Okazaki, Japan
| | - Mami Kato
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan.,Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Masataka Sunagawa
- Department of Physiology, Showa University School of Medicine, Shinagawa, Japan
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11
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Al Awabdh S, Donneger F, Goutierre M, Séveno M, Vigy O, Weinzettl P, Russeau M, Moutkine I, Lévi S, Marin P, Poncer JC. Gephyrin Interacts with the K-Cl Cotransporter KCC2 to Regulate Its Surface Expression and Function in Cortical Neurons. J Neurosci 2022; 42:166-182. [PMID: 34810232 PMCID: PMC8802937 DOI: 10.1523/jneurosci.2926-20.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 08/31/2021] [Accepted: 10/17/2021] [Indexed: 11/21/2022] Open
Abstract
The K+-Cl- cotransporter KCC2, encoded by the Slc12a5 gene, is a neuron-specific chloride extruder that tunes the strength and polarity of GABAA receptor-mediated transmission. In addition to its canonical ion transport function, KCC2 also regulates spinogenesis and excitatory synaptic function through interaction with a variety of molecular partners. KCC2 is enriched in the vicinity of both glutamatergic and GABAergic synapses, the activity of which in turn regulates its membrane stability and function. KCC2 interaction with the submembrane actin cytoskeleton via 4.1N is known to control its anchoring near glutamatergic synapses on dendritic spines. However, the molecular determinants of KCC2 clustering near GABAergic synapses remain unknown. Here, we used proteomics to identify novel KCC2 interacting proteins in the adult rat neocortex. We identified both known and novel candidate KCC2 partners, including some involved in neuronal development and synaptic transmission. These include gephyrin, the main scaffolding molecule at GABAergic synapses. Gephyrin interaction with endogenous KCC2 was confirmed by immunoprecipitation from rat neocortical extracts. We showed that gephyrin stabilizes plasmalemmal KCC2 and promotes its clustering in hippocampal neurons, mostly but not exclusively near GABAergic synapses, thereby controlling KCC2-mediated chloride extrusion. This study identifies gephyrin as a novel KCC2 anchoring molecule that regulates its membrane expression and function in cortical neurons.SIGNIFICANCE STATEMENT Fast synaptic inhibition in the brain is mediated by chloride-permeable GABAA receptors (GABAARs) and therefore relies on transmembrane chloride gradients. In neurons, these gradients are primarily maintained by the K/Cl cotransporter KCC2. Therefore, understanding the mechanisms controlling KCC2 expression and function is crucial to understand its physiological regulation and rescue its function in the pathology. KCC2 function depends on its membrane expression and clustering, but the underlying mechanisms remain unknown. We describe the interaction between KCC2 and gephyrin, the main scaffolding protein at inhibitory synapses. We show that gephyrin controls plasmalemmal KCC2 clustering and that loss of gephyrin compromises KCC2 function. Our data suggest functional units comprising GABAARs, gephyrin, and KCC2 act to regulate synaptic GABA signaling.
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Affiliation(s)
- Sana Al Awabdh
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Florian Donneger
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Marie Goutierre
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Martial Séveno
- BCM, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Oana Vigy
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Pauline Weinzettl
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
- Institute of Biotechnology, University of Applied Sciences, Krems, Austria
| | - Marion Russeau
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Imane Moutkine
- 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
| | - Philippe Marin
- IGF, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Jean Christophe Poncer
- INSERM UMR-S 1270, 75005 Paris, France
- Sorbonne Université, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
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12
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The Important Role of Ion Transport System in Cervical Cancer. Int J Mol Sci 2021; 23:ijms23010333. [PMID: 35008759 PMCID: PMC8745646 DOI: 10.3390/ijms23010333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 12/15/2022] Open
Abstract
Cervical cancer is a significant gynecological cancer and causes cancer-related deaths worldwide. Human papillomavirus (HPV) is implicated in the etiology of cervical malignancy. However, much evidence indicates that HPV infection is a necessary but not sufficient cause in cervical carcinogenesis. Therefore, the cellular pathophysiology of cervical cancer is worthy of study. This review summarizes the recent findings concerning the ion transport processes involved in cell volume regulation and intracellular Ca2+ homeostasis of epithelial cells and how these transport systems are themselves regulated by the tumor microenvironment. For cell volume regulation, we focused on the volume-sensitive Cl− channels and K+-Cl− cotransporter (KCC) family, important regulators for ionic and osmotic homeostasis of epithelial cells. Regarding intracellular Ca2+ homeostasis, the Ca2+ store sensor STIM molecules and plasma membrane Ca2+ channel Orai proteins, the predominant Ca2+ entry mechanism in epithelial cells, are discussed. Furthermore, we evaluate the potential of these membrane ion transport systems as diagnostic biomarkers and pharmacological interventions and highlight the challenges.
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13
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Hamze M, Medina I, Delmotte Q, Porcher C. Contribution of Smoothened Receptor Signaling in GABAergic Neurotransmission and Chloride Homeostasis in the Developing Rodent Brain. Front Physiol 2021; 12:798066. [PMID: 34955901 PMCID: PMC8703190 DOI: 10.3389/fphys.2021.798066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
In the early stages of the central nervous system growth and development, γ-aminobutyric acid (GABA) plays an instructive trophic role for key events including neurogenesis, migration, synaptogenesis, and network formation. These actions are associated with increased concentration of chloride ions in immature neurons [(Cl−)i] that determines the depolarizing strength of ion currents mediated by GABAA receptors, a ligand-gated Cl− permeable ion channel. During neuron maturation the (Cl−)i progressively decreases leading to weakening of GABA induced depolarization and enforcing GABA function as principal inhibitory neurotransmitter. A neuron restricted potassium-chloride co-transporter KCC2 is a key molecule governing Cl− extrusion and determining the resting level of (Cl−)i in developing and mature mammalian neurons. Among factors controlling the functioning of KCC2 and the maturation of inhibitory circuits, is Smoothened (Smo), the transducer in the receptor complex of the developmental protein Sonic Hedgehog (Shh). Too much or too little Shh-Smo action will have mirror effects on KCC2 stability at the neuron membrane, the GABA inhibitory strength, and ultimately on the newborn susceptibility to neurodevelopmental disorders. Both canonical and non-canonical Shh-Smo signal transduction pathways contribute to the regulation of KCC2 and GABAergic synaptic activity. In this review, we discuss the recent findings of the action of Shh-Smo signaling pathways on chloride ions homeostasis through the control of KCC2 membrane trafficking, and consequently on inhibitory neurotransmission and network activity during postnatal development.
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Affiliation(s)
- Mira Hamze
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Igor Medina
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Quentin Delmotte
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
| | - Christophe Porcher
- Aix-Marseille University, INSERM, INMED, Parc Scientifique de Luminy, Marseille, France.,INSERM (Institut National de la Santé et de la Recherche Médicale) Unité, Parc Scientifique de Luminy, Marseille, France.,INMED (Institut de Neurobiologie de la Méditerranée), Parc Scientifique de Luminy, Marseille, France
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14
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Portioli C, Ruiz Munevar MJ, De Vivo M, Cancedda L. Cation-coupled chloride cotransporters: chemical insights and disease implications. TRENDS IN CHEMISTRY 2021; 3:832-849. [PMID: 34604727 PMCID: PMC8461084 DOI: 10.1016/j.trechm.2021.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cation-coupled chloride cotransporters (CCCs) modulate the transport of sodium and/or potassium cations coupled with chloride anions across the cell membrane. CCCs thus help regulate intracellular ionic concentration and consequent cell volume homeostasis. This has been largely exploited in the past to develop diuretic drugs that act on CCCs expressed in the kidney. However, a growing wealth of evidence has demonstrated that CCCs are also critically involved in a great variety of other pathologies, motivating most recent drug discovery programs targeting CCCs. Here, we examine the structure–function relationship of CCCs. By linking recent high-resolution cryogenic electron microscopy (cryo-EM) data with older biochemical/functional studies on CCCs, we discuss the mechanistic insights and opportunities to design selective CCC modulators to treat diverse pathologies. The structural topology and function of all cation-coupled chloride cotransporters (CCCs) have been continuously investigated over the past 40 years, with great progress also thanks to the recent cryogenic electron microscopy (cryo-EM) resolution of the structures of five CCCs. In particular, such studies have clarified the structure–function relationship for the Na-K-Cl cotransporter NKCC1 and K-Cl cotransporters KCC1–4. The constantly growing evidence of the crucial involvement of CCCs in physiological and various pathological conditions, as well as the evidence of their wide expression in diverse body tissues, has promoted CCCs as targets for the discovery and development of new, safer, and more selective/effective drugs for a plethora of pathologies. Post-translational modification anchor points on the structure of CCCs may offer alternative strategies for small molecule drug discovery.
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Affiliation(s)
- Corinne Portioli
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | | | - Marco De Vivo
- Laboratory of Molecular Modeling and Drug Discovery, IIT, Via Morego, 30 16163 Genoa, Italy
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.,Dulbecco Telethon Institute, Via Varese 16b, 00185 Rome, Italy
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15
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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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16
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Murillo-de-Ozores AR, Chávez-Canales M, de los Heros P, Gamba G, Castañeda-Bueno M. Physiological Processes Modulated by the Chloride-Sensitive WNK-SPAK/OSR1 Kinase Signaling Pathway and the Cation-Coupled Chloride Cotransporters. Front Physiol 2020; 11:585907. [PMID: 33192599 PMCID: PMC7606576 DOI: 10.3389/fphys.2020.585907] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/29/2020] [Indexed: 12/15/2022] Open
Abstract
The role of Cl- as an intracellular signaling ion has been increasingly recognized in recent years. One of the currently best described roles of Cl- in signaling is the modulation of the With-No-Lysine (K) (WNK) - STE20-Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive Kinase 1 (OSR1) - Cation-Coupled Cl- Cotransporters (CCCs) cascade. Binding of a Cl- anion to the active site of WNK kinases directly modulates their activity, promoting their inhibition. WNK activation due to Cl- release from the binding site leads to phosphorylation and activation of SPAK/OSR1, which in turn phosphorylate the CCCs. Phosphorylation by WNKs-SPAK/OSR1 of the Na+-driven CCCs (mediating ions influx) promote their activation, whereas that of the K+-driven CCCs (mediating ions efflux) promote their inhibition. This results in net Cl- influx and feedback inhibition of WNK kinases. A wide variety of alterations to this pathway have been recognized as the cause of several human diseases, with manifestations in different systems. The understanding of WNK kinases as Cl- sensitive proteins has allowed us to better understand the mechanistic details of regulatory processes involved in diverse physiological phenomena that are reviewed here. These include cell volume regulation, potassium sensing and intracellular signaling in the renal distal convoluted tubule, and regulation of the neuronal response to the neurotransmitter GABA.
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Affiliation(s)
- Adrián Rafael Murillo-de-Ozores
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Chávez-Canales
- Unidad de Investigación UNAM-INC, Instituto Nacional de Cardiología Ignacio Chávez and Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Paola de los Heros
- Unidad de Investigación UNAM-INC, Research Division, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gerardo Gamba
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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17
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Reid MS, Kern DM, Brohawn SG. Cryo-EM structure of the potassium-chloride cotransporter KCC4 in lipid nanodiscs. eLife 2020; 9:e52505. [PMID: 32286222 PMCID: PMC7200160 DOI: 10.7554/elife.52505] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 04/12/2020] [Indexed: 01/24/2023] Open
Abstract
Cation-chloride-cotransporters (CCCs) catalyze transport of Cl- with K+ and/or Na+across cellular membranes. CCCs play roles in cellular volume regulation, neural development and function, audition, regulation of blood pressure, and renal function. CCCs are targets of clinically important drugs including loop diuretics and their disruption has been implicated in pathophysiology including epilepsy, hearing loss, and the genetic disorders Andermann, Gitelman, and Bartter syndromes. Here we present the structure of a CCC, the Mus musculus K+-Cl- cotransporter (KCC) KCC4, in lipid nanodiscs determined by cryo-EM. The structure, captured in an inside-open conformation, reveals the architecture of KCCs including an extracellular domain poised to regulate transport activity through an outer gate. We identify binding sites for substrate K+ and Cl- ions, demonstrate the importance of key coordinating residues for transporter activity, and provide a structural explanation for varied substrate specificity and ion transport ratio among CCCs. These results provide mechanistic insight into the function and regulation of a physiologically important transporter family.
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Affiliation(s)
- Michelle S Reid
- Department of Molecular and Cell Biology, University of California BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California BerkeleyBerkeleyUnited States
| | - David M Kern
- Department of Molecular and Cell Biology, University of California BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California BerkeleyBerkeleyUnited States
| | - Stephen Graf Brohawn
- Department of Molecular and Cell Biology, University of California BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California BerkeleyBerkeleyUnited States
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18
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Venugopalan P, Cameron EG, Zhang X, Nahmou M, Muller KJ, Goldberg JL. Physiologic maturation is both extrinsically and intrinsically regulated in progenitor-derived neurons. Sci Rep 2020; 10:2337. [PMID: 32047174 PMCID: PMC7012889 DOI: 10.1038/s41598-020-58120-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/03/2020] [Indexed: 12/15/2022] Open
Abstract
During development, newly-differentiated neurons undergo several morphological and physiological changes to become functional, mature neurons. Physiologic maturation of neuronal cells derived from isolated stem or progenitor cells may provide insight into maturation in vivo but is not well studied. As a step towards understanding how neuronal maturation is regulated, we studied the developmental switch of response to the neurotransmitter GABA, from excitatory depolarization to inhibitory hyperpolarization. We compared acutely isolated retinal ganglion cells (RGCs) at various developmental stages and RGCs differentiated in vitro from embryonic retinal progenitors for the effects of aging and, independently, of retinal environment age on their GABAA receptor (GABAAR) responses, elicited by muscimol. We found that neurons generated in vitro from progenitors exhibited depolarizing, immature GABA responses, like those of early postnatal RGCs. As progenitor-derived neurons aged from 1 to 3 weeks, their GABA responses matured. Interestingly, signals secreted by the early postnatal retina suppressed acquisition of mature GABA responses. This suppression was not associated with changes in expression of GABAAR or of the chloride co-transporter KCC2, but rather with inhibition of KCC2 dimerization in differentiating neurons. Taken together, these data indicate GABA response maturation depends on release of inhibition by developmentally regulated diffusible signals from the retina.
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Affiliation(s)
- Praseeda Venugopalan
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Evan G Cameron
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Xiong Zhang
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Michael Nahmou
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Kenneth J Muller
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Department of Physiology & Biophysics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Jeffrey L Goldberg
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA.
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA.
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19
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The Roles of GABA in Ischemia-Reperfusion Injury in the Central Nervous System and Peripheral Organs. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4028394. [PMID: 31814874 PMCID: PMC6878816 DOI: 10.1155/2019/4028394] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/27/2019] [Accepted: 10/18/2019] [Indexed: 12/30/2022]
Abstract
Ischemia-reperfusion (I/R) injury is a common pathological process, which may lead to dysfunctions and failures of multiple organs. A flawless medical way of endogenous therapeutic target can illuminate accurate clinical applications. γ-Aminobutyric acid (GABA) has been known as a marker in I/R injury of the central nervous system (mainly in the brain) for a long time, and it may play a vital role in the occurrence of I/R injury. It has been observed that throughout cerebral I/R, levels, syntheses, releases, metabolisms, receptors, and transmissions of GABA undergo complex pathological variations. Scientists have investigated the GABAergic enhancers for attenuating cerebral I/R injury; however, discussions on existing problems and mechanisms of available drugs were seldom carried out so far. Therefore, this review would summarize the process of pathological variations in the GABA system under cerebral I/R injury and will cover corresponding probable issues and mechanisms in using GABA-related drugs to illuminate the concern about clinical illness for accurately preventing cerebral I/R injury. In addition, the study will summarize the increasing GABA signals that can prevent I/R injuries occurring in peripheral organs, and the roles of GABA were also discussed correspondingly.
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20
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Petrov AM, Mast N, Li Y, Pikuleva IA. The key genes, phosphoproteins, processes, and pathways affected by efavirenz-activated CYP46A1 in the amyloid-decreasing paradigm of efavirenz treatment. FASEB J 2019; 33:8782-8798. [PMID: 31063705 DOI: 10.1096/fj.201900092r] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Efavirenz (EFV) is an anti-HIV drug, and cytochrome P450 46A1 (CYP46A1) is the major brain cholesterol hydroxylase. Previously, we discovered that EFV activates CYP46A1 and improves behavioral performance in 5XFAD mice, an Alzheimer's disease model. Herein, the unbiased omics and other approaches were used to study 5XFAD mice in the amyloid-decreasing paradigm of CYP46A1 activation by EFV. These approaches revealed increases in the brain levels of postsynaptic density protein 95, gephyrin, synaptophysin, synapsin, glial fibrillary acidic protein, and CYP46A1 and documented altered expression and phosphorylation of 66 genes and 77 proteins, respectively. The data obtained pointed to EFV effects at the synaptic level, plasmin-depended amyloid clearance, inflammation and microglia phenotype, oxidative stress and cellular hypoxia, autophagy and ubiquitin-proteasome systems as well as apoptosis. These effects could be realized in part via changes in the Ca2+-, small GTPase, and catenin signaling. A model is proposed, in which CYP46A1-dependent lipid raft rearrangement and subsequent decrease of protein phosphorylation are central in EFV effects and explain behavioral improvements in EFV-treated 5XFAD mice.-Petrov, A. M., Mast, N., Li, Y., Pikuleva, I. A. The key genes, phosphoproteins, processes, and pathways affected by efavirenz-activated CYP46A1 in the amyloid-decreasing paradigm of efavirenz treatment.
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Affiliation(s)
- Alexey M Petrov
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yong Li
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
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21
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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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22
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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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23
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Cordshagen A, Busch W, Winklhofer M, Nothwang HG, Hartmann AM. Phosphoregulation of the intracellular termini of K +-Cl - cotransporter 2 (KCC2) enables flexible control of its activity. J Biol Chem 2018; 293:16984-16993. [PMID: 30201606 DOI: 10.1074/jbc.ra118.004349] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/01/2018] [Indexed: 12/22/2022] Open
Abstract
The pivotal role of K+-Cl- cotransporter 2 (KCC2) in inhibitory neurotransmission and severe human diseases fosters interest in understanding posttranslational regulatory mechanisms such as (de)phosphorylation. Here, the regulatory role of the five bona fide phosphosites Ser31, Thr34, Ser932, Thr999, and Thr1008 was investigated by the use of alanine and aspartate mutants. Tl+-based flux analyses in HEK-293 cells demonstrated increased transport activity for S932D (mimicking phosphorylation) and T1008A (mimicking dephosphorylation), albeit to a different extent. Increased activity was due to changes in intrinsic activity, as it was not caused by increased cell-surface abundance. Substitutions of Ser31, Thr34, or Thr999 had no effect. Additionally, we show that the indirect actions of the known KCC2 activators staurosporine and N-ethylmaleimide (NEM) involved multiple phosphosites. S31D, T34A, S932A/D, T999A, or T1008A/D abrogated staurosporine mediated stimulation, and S31A, T34D, or S932D abolished NEM-mediated stimulation. This demonstrates for the first time differential effects of staurosporine and NEM on KCC2. In addition, the staurosporine-mediated effects involved both KCC2 phosphorylation and dephosphorylation with Ser932 and Thr1008 being bona fide target sites. In summary, our data reveal a complex phosphoregulation of KCC2 that provides the transporter with a toolbox for graded activity and integration of different signaling pathways.
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Affiliation(s)
- Antje Cordshagen
- From the Neurogenetics group, Center of Excellence Hearing4all, School of Medicine and Health Sciences
| | - Wiebke Busch
- From the Neurogenetics group, Center of Excellence Hearing4all, School of Medicine and Health Sciences
| | - Michael Winklhofer
- Institute for Biology and Environmental Sciences IBU, and.,Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Hans Gerd Nothwang
- From the Neurogenetics group, Center of Excellence Hearing4all, School of Medicine and Health Sciences.,Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Anna-Maria Hartmann
- From the Neurogenetics group, Center of Excellence Hearing4all, School of Medicine and Health Sciences, .,Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
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24
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Dai S, Qi Y, Fu J, Li N, Zhang X, Zhang J, Zhang W, Xu H, Zhou H, Ma Z. Dexmedetomidine attenuates persistent postsurgical pain by upregulating K +-Cl - cotransporter-2 in the spinal dorsal horn in rats. J Pain Res 2018; 11:993-1004. [PMID: 29872336 PMCID: PMC5973459 DOI: 10.2147/jpr.s158737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Dexmedetomidine (DEX) could have an analgesic effect on pain transmission through the modulation of brain-derived neurotrophic factor (BDNF). In addition, KCC2-induced shift in neuronal Cl− homeostasis is crucial for postsynaptic inhibition mediated by GABAA receptors. Accumulating evidence shows that nerve injury, peripheral inflammation and stress activate the spinal BDNF/TrkB signal, which results in the downregulation of KCC2 transport and expression, eventually leads to GAGAergic disinhibition and hyperalgesia. The aim of this experiment was to explore the interaction between DEX and KCC2 at a molecular level in rats in the persistent postsurgical pain (PPSP). Methods PPSP in rats was evoked by the skin/muscle incision and retraction (SMIR). Mechanical hypersensitivity was assessed with the Dynamic Plantar Aesthesiometer. Western blot and immunofluorescence assay were used to assess the expressions of related proteins. Results In the first part of our experiment, the results revealed that the BDNF/TrkB-KCC2 signal plays a critical role in the development of SMIR-evoked PPSP; the second part showed that intraperitoneal administrations of 40 µg/kg DEX at 15 min presurgery and 1 to 3 days post-surgery significantly attenuated SMIR-evoked PPSP. Simultaneously, SMIR-induced KCC2 downregulation was partly reversed, which coincided with the inhibition of the BDNF/TrkB signal in the spinal dorsal horn. Moreover, intrathecal administrations of KCC2 inhibitor VU0240551 significantly reduced the analgesic effect of DEX on SMIR-evoked PPSP. Conclusion The results of our study indicated that DEX attenuated PPSP by restoring KCC2 function through reducing BDNF/TrkB signal in the spinal dorsal horn in rats, which provides a new insight into the treatment of chronic pain in clinical postsurgical pain management.
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Affiliation(s)
- Shuhong Dai
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Yu Qi
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Jie Fu
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Na Li
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Xu Zhang
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Juan Zhang
- The Affiliated Nanjing Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China
| | - Wei Zhang
- The Affiliated Nanjing Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China
| | - Haijun Xu
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Hai Zhou
- Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China
| | - Zhengliang Ma
- The Affiliated Nanjing Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China
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25
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Schulte JT, Wierenga CJ, Bruining H. Chloride transporters and GABA polarity in developmental, neurological and psychiatric conditions. Neurosci Biobehav Rev 2018; 90:260-271. [PMID: 29729285 DOI: 10.1016/j.neubiorev.2018.05.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/20/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022]
Abstract
Neuronal chloride regulation is a determinant factor for the dynamic tuning of GABAergic inhibition during and beyond brain development. This regulation is mainly dependent on the two co-transporters K+/Cl- co-transporter KCC2 and Na+/K+/Cl- co-transporter NKCC1, whose activity can decrease or increase neuronal chloride concentrations respectively. Altered expression and/or activity of either of these co-transporters has been associated with a wide variety of brain disorders including developmental disorders, epilepsy, schizophrenia and stroke. Here, we review current knowledge on chloride transporter expression and activity regulation and highlight the intriguing potential for existing and future interventions to support chloride homeostasis across a wide range of mental disorders and neurological conditions.
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Affiliation(s)
- Joran T Schulte
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands
| | - Corette J Wierenga
- Division of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hilgo Bruining
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands.
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26
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Kitayama T. The Role of K +-Cl --Cotransporter-2 in Neuropathic Pain. Neurochem Res 2018; 43:110-115. [PMID: 28677029 DOI: 10.1007/s11064-017-2344-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/09/2017] [Accepted: 06/26/2017] [Indexed: 01/21/2023]
Abstract
The pain sensory system normally functions under a fine balance between excitation and inhibition. When this balance is perturbed for some reason, it leads to neuropathic pain. There is accumulating evidence that attributes this pain generation to specific dysfunctions of the inhibitory system in the spinal cord. One possible mechanism leading to the induction of these dysfunctions is the down-regulation of K+-Cl--cotransporter-2 (KCC2) expression. In fact, various neuropathic pain models indicate a decrease of KCC2 expression in the spinal cord. The alteration of KCC2 expression affects GABAergic and glycinergic neurotransmissions, because KCC2 is a potassium-chloride exporter and serves to maintain intracellular chloride concentration. When there is a low level of KCC2 expression, GABAergic and glycinergic neurotransmissions transform from inhibitory signals to excitatory signals. In this review, the hypothesis that an alteration of KCC2 expression has a crucial influence on the initiation/development or maintenance of neuropathic pain is discussed. In addition, it is suggested that the alteration of inhibitory signals is dependent on the time after peripheral nerve injury.
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Affiliation(s)
- Tomoya Kitayama
- Department of Pharmacy, School of Pharmacy and Pharmaceutical Science, Mukogawa Women's University, 11-68 Koshien-Kyubanmachi, Nishinomiya, Hyogo, 663-8179, Japan.
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27
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Heubl M, Zhang J, Pressey JC, Al Awabdh S, Renner M, Gomez-Castro F, Moutkine I, Eugène E, Russeau M, Kahle KT, Poncer JC, Lévi S. GABA A receptor dependent synaptic inhibition rapidly tunes KCC2 activity via the Cl --sensitive WNK1 kinase. Nat Commun 2017; 8:1776. [PMID: 29176664 PMCID: PMC5701213 DOI: 10.1038/s41467-017-01749-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 10/13/2017] [Indexed: 02/08/2023] Open
Abstract
The K+-Cl- co-transporter KCC2 (SLC12A5) tunes the efficacy of GABAA receptor-mediated transmission by regulating the intraneuronal chloride concentration [Cl-]i. KCC2 undergoes activity-dependent regulation in both physiological and pathological conditions. The regulation of KCC2 by synaptic excitation is well documented; however, whether the transporter is regulated by synaptic inhibition is unknown. Here we report a mechanism of KCC2 regulation by GABAA receptor (GABAAR)-mediated transmission in mature hippocampal neurons. Enhancing GABAAR-mediated inhibition confines KCC2 to the plasma membrane, while antagonizing inhibition reduces KCC2 surface expression by increasing the lateral diffusion and endocytosis of the transporter. This mechanism utilizes Cl- as an intracellular secondary messenger and is dependent on phosphorylation of KCC2 at threonines 906 and 1007 by the Cl--sensing kinase WNK1. We propose this mechanism contributes to the homeostasis of synaptic inhibition by rapidly adjusting neuronal [Cl-]i to GABAAR activity.
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Affiliation(s)
- Martin Heubl
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Jinwei Zhang
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratory, Exeter, EX4 4PS, UK
- Departments of Neurosurgery, Pediatrics, and Cellular & Molecular Physiology, NIH-Yale Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Jessica C Pressey
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Sana Al Awabdh
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Marianne Renner
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Ferran Gomez-Castro
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Imane Moutkine
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Emmanuel Eugène
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Marion Russeau
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Kristopher T Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular & Molecular Physiology, NIH-Yale Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Jean Christophe Poncer
- Inserm UMR-S 839, 75005, Paris, France
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France
- Institut du Fer à Moulin, 75005, Paris, France
| | - Sabine Lévi
- Inserm UMR-S 839, 75005, Paris, France.
- Université Pierre & Marie Curie, Sorbonne Universités, 75005, Paris, France.
- Institut du Fer à Moulin, 75005, Paris, France.
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28
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Abstract
K+-Cl- co-transporter 2 (KCC2/SLC12A5) is a neuronal specific cation chloride co-transporter which is active under isotonic conditions, and thus a key regulator of intracellular Cl- levels. It also has an ion transporter-independent structural role in modulating the maturation and regulation of excitatory glutamatergic synapses. KCC2 levels are developmentally regulated, and a postnatal upregulation of KCC2 generates a low intracellular chloride concentration that allows the neurotransmitters γ-aminobutyric acid (GABA) and glycine to exert inhibitory neurotransmission through its Cl- permeating channel. Functional expression of KCC2 at the neuronal cell surface is necessary for its activity, and impairment in KCC2 cell surface transport and/or internalization may underlie a range of neuropathological conditions. Although recent advances have shed light on a range of cellular mechanisms regulating KCC2 activity, little is known about its membrane trafficking itinerary and regulatory proteins. In this review, known membrane trafficking signals, pathways and mechanisms pertaining to KCC2's functional surface expression are discussed.
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Affiliation(s)
- Bor Luen Tang
- a Department of Biochemistry, Yong Loo Lin School of Medicine , National University Health System , Singapore.,b NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore
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29
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Markkanen M, Ludwig A, Khirug S, Pryazhnikov E, Soni S, Khiroug L, Delpire E, Rivera C, Airaksinen MS, Uvarov P. Implications of the N-terminal heterogeneity for the neuronal K-Cl cotransporter KCC2 function. Brain Res 2017; 1675:87-101. [PMID: 28888841 DOI: 10.1016/j.brainres.2017.08.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 08/25/2017] [Accepted: 08/30/2017] [Indexed: 12/16/2022]
Abstract
The neuron-specific K-Cl cotransporter KCC2 maintains the low intracellular chloride concentration required for the fast hyperpolarizing responses of the inhibitory neurotransmitters γ-aminobutyric acid (GABA) and glycine. The two KCC2 isoforms, KCC2a and KCC2b differ by their N-termini as a result of alternative promoter usage. Whereas the role of KCC2b in mediating the chloride transport is unequivocal, the physiological role of KCC2a in neurons has remained obscure. We show that KCC2a isoform can decrease the intracellular chloride concentration in cultured neurons and attenuate calcium responses evoked by application of the GABAA receptor agonist muscimol. While the biotinylation assay detected both KCC2 isoforms at the cell surface of cultured neurons, KCC2a was not detected at the plasma membrane in immunostainings, suggesting that the N-terminal KCC2a epitope is masked. Confirming this hypothesis, KCC2a surface expression was detected by the C-terminal KCC2 pan antibody but not by the N-terminal KCC2a antibody in KCC2b-deficient neurons. One possible cause for the epitope masking is the binding site of Ste20-related proline-alanine-rich kinase (SPAK) in the KCC2a N-terminus. SPAK, a known regulator of K-Cl cotransporters, was co-immunoprecipitated in a complex with KCC2a but not KCC2b isoform. Moreover, SPAK overexpression decreased the transport activity of KCC2a but not that of KCC2b, as revealed by rubidium flux assay in HEK293 cells. Thus, our data indicate that both KCC2 isoforms perform as chloride cotransporters in neuronal cells, while their N-terminal heterogeneity could play an important role in fine-tuning of the K-Cl transport activity.
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Affiliation(s)
- Marika Markkanen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | | | | | | | - Shetal Soni
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Leonard Khiroug
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Claudio Rivera
- Neuroscience Center, University of Helsinki, Helsinki, Finland; INSERM, Institut de Neurobiologie de la Méditerranée (INMED), Marseille, France; Aix-Marseille Université, UMR901 Marseille, France
| | - Matti S Airaksinen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - Pavel Uvarov
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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30
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Garneau AP, Marcoux AA, Frenette-Cotton R, Mac-Way F, Lavoie JL, Isenring P. Molecular insights into the normal operation, regulation, and multisystemic roles of K +-Cl - cotransporter 3 (KCC3). Am J Physiol Cell Physiol 2017; 313:C516-C532. [PMID: 28814402 DOI: 10.1152/ajpcell.00106.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/26/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022]
Abstract
Long before the molecular identity of the Na+-dependent K+-Cl- cotransporters was uncovered in the mid-nineties, a Na+-independent K+-Cl- cotransport system was also known to exist. It was initially observed in sheep and goat red blood cells where it was shown to be ouabain-insensitive and to increase in the presence of N-ethylmaleimide (NEM). After it was established between the early and mid-nineties, the expressed sequence tag (EST) databank was found to include a sequence that was highly homologous to those of the Na+-dependent K+-Cl- cotransporters. This sequence was eventually found to code for the Na+-independent K+-Cl- cotransport function that was described in red blood cells several years before. It was termed KCC1 and led to the discovery of three isoforms called KCC2, KCC3, and KCC4. Since then, it has become obvious that each one of these isoforms exhibits unique patterns of distribution and fulfills distinct physiological roles. Among them, KCC3 has been the subject of great attention in view of its important role in the nervous system and its association with a rare hereditary sensorimotor neuropathy (called Andermann syndrome) that affects many individuals in Quebec province (Canada). It was also found to play important roles in the cardiovascular system, the organ of Corti, and circulating blood cells. As will be seen in this review, however, there are still a number of uncertainties regarding the transport properties, structural organization, and regulation of KCC3. The same is true regarding the mechanisms by which KCC3 accomplishes its numerous functions in animal cells.
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Affiliation(s)
- A P Garneau
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
- Cardiometabolic Axis, Kinesiology Department, University of Montréal, Montreal, Quebec, Canada
| | - A A Marcoux
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - R Frenette-Cotton
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - F Mac-Way
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - J L Lavoie
- Cardiometabolic Axis, Kinesiology Department, University of Montréal, Montreal, Quebec, Canada
| | - P Isenring
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
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31
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Mahadevan V, Khademullah CS, Dargaei Z, Chevrier J, Uvarov P, Kwan J, Bagshaw RD, Pawson T, Emili A, De Koninck Y, Anggono V, Airaksinen M, Woodin MA. Native KCC2 interactome reveals PACSIN1 as a critical regulator of synaptic inhibition. eLife 2017; 6:e28270. [PMID: 29028184 PMCID: PMC5640428 DOI: 10.7554/elife.28270] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/08/2017] [Indexed: 01/01/2023] Open
Abstract
KCC2 is a neuron-specific K+-Cl- cotransporter essential for establishing the Cl- gradient required for hyperpolarizing inhibition in the central nervous system (CNS). KCC2 is highly localized to excitatory synapses where it regulates spine morphogenesis and AMPA receptor confinement. Aberrant KCC2 function contributes to human neurological disorders including epilepsy and neuropathic pain. Using functional proteomics, we identified the KCC2-interactome in the mouse brain to determine KCC2-protein interactions that regulate KCC2 function. Our analysis revealed that KCC2 interacts with diverse proteins, and its most predominant interactors play important roles in postsynaptic receptor recycling. The most abundant KCC2 interactor is a neuronal endocytic regulatory protein termed PACSIN1 (SYNDAPIN1). We verified the PACSIN1-KCC2 interaction biochemically and demonstrated that shRNA knockdown of PACSIN1 in hippocampal neurons increases KCC2 expression and hyperpolarizes the reversal potential for Cl-. Overall, our global native-KCC2 interactome and subsequent characterization revealed PACSIN1 as a novel and potent negative regulator of KCC2.
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Affiliation(s)
- Vivek Mahadevan
- Department of Cell and Systems BiologyUniversity of TorontoTorontoCanada
| | | | - Zahra Dargaei
- Department of Cell and Systems BiologyUniversity of TorontoTorontoCanada
| | - Jonah Chevrier
- Department of Cell and Systems BiologyUniversity of TorontoTorontoCanada
| | - Pavel Uvarov
- Department of Anatomy, Faculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Julian Kwan
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular ResearchUniversity of TorontoTorontoCanada
| | - Richard D Bagshaw
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Tony Pawson
- Lunenfeld-Tanenbaum Research InstituteMount Sinai HospitalTorontoCanada
| | - Andrew Emili
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular ResearchUniversity of TorontoTorontoCanada
| | - Yves De Koninck
- Institut Universitaire en Santé Mentale de QuébecQuébecCanada
- Department of Psychiatry and NeuroscienceUniversité LavalQuébecCanada
| | - Victor Anggono
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia ResearchThe University of QueenslandBrisbaneAustralia
| | - Matti Airaksinen
- Department of Anatomy, Faculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Melanie A Woodin
- Department of Cell and Systems BiologyUniversity of TorontoTorontoCanada
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32
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Wright R, Newey SE, Ilie A, Wefelmeyer W, Raimondo JV, Ginham R, Mcllhinney RAJ, Akerman CJ. Neuronal Chloride Regulation via KCC2 Is Modulated through a GABA B Receptor Protein Complex. J Neurosci 2017; 37:5447-5462. [PMID: 28450542 PMCID: PMC5452337 DOI: 10.1523/jneurosci.2164-16.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 01/06/2023] Open
Abstract
GABAB receptors are G-protein-coupled receptors that mediate inhibitory synaptic actions through a series of downstream target proteins. It is increasingly appreciated that the GABAB receptor forms part of larger signaling complexes, which enable the receptor to mediate multiple different effects within neurons. Here we report that GABAB receptors can physically associate with the potassium-chloride cotransporter protein, KCC2, which sets the driving force for the chloride-permeable ionotropic GABAA receptor in mature neurons. Using biochemical, molecular, and functional studies in rodent hippocampus, we show that activation of GABAB receptors results in a decrease in KCC2 function, which is associated with a reduction in the protein at the cell surface. These findings reveal a novel "crosstalk" between the GABA receptor systems, which can be recruited under conditions of high GABA release and which could be important for the regulation of inhibitory synaptic transmission.SIGNIFICANCE STATEMENT Synaptic inhibition in the brain is mediated by ionotropic GABAA receptors (GABAARs) and metabotropic GABAB receptors (GABABRs). To fully appreciate the function and regulation of these neurotransmitter receptors, we must understand their interactions with other proteins. We describe a novel association between the GABABR and the potassium-chloride cotransporter protein, KCC2. This association is significant because KCC2 sets the intracellular chloride concentration found in mature neurons and thereby establishes the driving force for the chloride-permeable GABAAR. We demonstrate that GABABR activation can regulate KCC2 at the cell surface in a manner that alters intracellular chloride and the reversal potential for the GABAAR. Our data therefore support an additional mechanism by which GABABRs are able to modulate fast synaptic inhibition.
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Affiliation(s)
| | | | | | | | | | - Rachel Ginham
- Medical Research Council Anatomical Neuropharmacology Unit, University of Oxford, Oxford, OX1 3QT, United Kingdom
| | - R A Jeffrey Mcllhinney
- Medical Research Council Anatomical Neuropharmacology Unit, University of Oxford, Oxford, OX1 3QT, United Kingdom
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33
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Chen L, Wan L, Wu Z, Ren W, Huang Y, Qian B, Wang Y. KCC2 downregulation facilitates epileptic seizures. Sci Rep 2017; 7:156. [PMID: 28279020 PMCID: PMC5427808 DOI: 10.1038/s41598-017-00196-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/13/2017] [Indexed: 11/18/2022] Open
Abstract
GABAA receptor-mediated inhibition depends on the maintenance of low level intracellular [Cl-] concentration, which in adult depends on neuron specific K+-Cl- cotransporter-2 (KCC2). Previous studies have shown that KCC2 was downregulated in both epileptic patients and various epileptic animal models. However, the temporal relationship between KCC2 downregulation and seizure induction is unclear yet. In this study, we explored the temporal relationship and the influence of KCC2 downregulation on seizure induction. Significant downregulation of plasma membrane KCC2 was directly associated with severe (Racine Score III and above) behavioral seizures in vivo, and occurred before epileptiform bursting activities in vitro induced by convulsant. Overexpression of KCC2 using KCC2 plasmid effectively enhanced resistance to convulsant-induced epileptiform bursting activities in vitro. Furthermore, suppression of membrane KCC2 expression, using shRNAKCC2 plasmid in vitro and shRNAKCC2 containing lentivirus in vivo, induced spontaneous epileptiform bursting activities in vitro and Racine III seizure behaviors accompanied by epileptic EEG in vivo. Our findings novelly demonstrated that altered expression of KCC2 is not the consequence of seizure occurrence but likely is the contributing factor.
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Affiliation(s)
- Lulan Chen
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Li Wan
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Zheng Wu
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Wanting Ren
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Yian Huang
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Binbin Qian
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
| | - Yun Wang
- Institutes of Brain Science, State Key Laboratory for Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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Gu W, Zhang W, Lei Y, Cui Y, Chu S, Gu X, Ma Z. Activation of spinal alpha-7 nicotinic acetylcholine receptor shortens the duration of remifentanil-induced postoperative hyperalgesia by upregulating KCC2 in the spinal dorsal horn in rats. Mol Pain 2017; 13:1744806917704769. [PMID: 28425312 PMCID: PMC6997724 DOI: 10.1177/1744806917704769] [Citation(s) in RCA: 9] [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: 11/05/2016] [Revised: 02/28/2017] [Accepted: 03/15/2017] [Indexed: 12/15/2022] Open
Abstract
Background Accumulating evidence has shown that the signal from spinal brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 plays a critical role in the process of pain hypersensitivity. The activation of alpha-7 nicotinic acetylcholine receptors could have an analgesic effect on remifentanil-induced postoperative hyperalgesia. Nevertheless, whether intrathecal administration of PNU-120596, an alpha-7 nicotinic acetylcholine receptors selective type II positive allosteric modulator, before surgery could affect the duration of remifentanil-induced postoperative hyperalgesia remains unknown, and the effects of alpha-7 nicotinic acetylcholine receptors activation on the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal in the spinal dorsal horn of rats with remifentanil-induced postoperative hyperalgesia is still enigmatic. Results We demonstrated that the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal played a critical role in the development of remifentanil-induced postoperative hyperalgesia. Intrathecal administration of PNU-120596 (8 µg/kg, 15 min before surgery) was associated with earlier signs of recovery from remifentanil-induced postoperative hyperalgesia. Simultaneously, remifentanil-induced postoperative hyperalgesia-induced K+-Cl- cotransporter-2 downregulation was partly reversed and coincided with a decreased expression of brain-derived neurotrophic factor/tyrosine receptor kinase B in the spinal dorsal horn, approximately correlating with the time course of the nociceptive behavior. Moreover, intrathecal administration of the K+-Cl- cotransporter-2 inhibitor VU0240551 significantly reduced the analgesic effect of PNU-120596 on remifentanil-induced postoperative hyperalgesia. Conclusions The activation of alpha-7 nicotinic acetylcholine receptors induced a shorter duration of remifentanil-induced postoperative hyperalgesia by restoring the brain-derived neurotrophic factor/tyrosine receptor kinase B-K+-Cl- cotransporter-2 signal in the spinal dorsal horn of rats, which provides new insight into treatment in clinical postoperative pain management.
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Affiliation(s)
- Wei Gu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
| | - Wei Zhang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
| | - Yishan Lei
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Yin Cui
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Shuaishuai Chu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Xiaoping Gu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical School of Nanjing University, Nanjing, China
| | - Zhengliang Ma
- Department of Anesthesiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China
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Doyon N, Vinay L, Prescott SA, De Koninck Y. Chloride Regulation: A Dynamic Equilibrium Crucial for Synaptic Inhibition. Neuron 2016; 89:1157-1172. [PMID: 26985723 DOI: 10.1016/j.neuron.2016.02.030] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 12/24/2015] [Accepted: 02/18/2016] [Indexed: 01/02/2023]
Abstract
Fast synaptic inhibition relies on tight regulation of intracellular Cl(-). Chloride dysregulation is implicated in several neurological and psychiatric disorders. Beyond mere disinhibition, the consequences of Cl(-) dysregulation are multifaceted and best understood in terms of a dynamical system involving complex interactions between multiple processes operating on many spatiotemporal scales. This dynamical perspective helps explain many unintuitive manifestations of Cl(-) dysregulation. Here we discuss how taking into account dynamical regulation of intracellular Cl(-) is important for understanding how synaptic inhibition fails, how to best detect that failure, why Cl(-) regulation is energetically so expensive, and the overall consequences for therapeutics.
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Affiliation(s)
- Nicolas Doyon
- Institut Universitaire en Santé Mentale de Québec, Québec, QC G1J 2G3, Canada; Department of Mathematics and Statistics, Université Laval, Québec, QC G1V 0A6, Canada
| | - Laurent Vinay
- Team P3M, Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, F-13385 Marseille, France
| | - Steven A Prescott
- Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Yves De Koninck
- Institut Universitaire en Santé Mentale de Québec, Québec, QC G1J 2G3, Canada; Department of Psychiatry and Neuroscience, Université Laval, Québec, QC, G1V 0A6, Canada.
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Wu H, Che X, Tang J, Ma F, Pan K, Zhao M, Shao A, Wu Q, Zhang J, Hong Y. The K(+)-Cl(-) Cotransporter KCC2 and Chloride Homeostasis: Potential Therapeutic Target in Acute Central Nervous System Injury. Mol Neurobiol 2016; 53:2141-51. [PMID: 25941074 DOI: 10.1007/s12035-015-9162-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 03/26/2015] [Indexed: 12/11/2022]
Abstract
The K(+)-Cl(-) cotransporter-2 (KCC2) is a well-known member of the electroneutral cation-chloride cotransporters with a restricted expression pattern to neurons. This transmembrane protein mediates the efflux of Cl(-) out of neurons and exerts a critical role in inhibitory γ-aminobutyric acidergic (GABAergic) and glycinergic neurotransmission. Moreover, KCC2 participates in the regulation of various physiological processes of neurons, including cell migration, dendritic outgrowth, spine morphology, and dendritic synaptogenesis. It is important to note that down-regulation of KCC2 is associated with the pathogenesis of multiple neurological diseases, which is of particular relevance to acute central nervous system (CNS) injury. In this review, we aim to survey the pathogenic significance of KCC2 down-regulation under the condition of acute CNS injuries. We propose that further elucidation of the molecular mechanisms regarding KCC2 down-regulation after acute CNS injuries is necessary because of potential promising avenues for prevention and treatment of acute CNS injury.
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Affiliation(s)
- Haijian Wu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Xiaoru Che
- Department of Cardiology, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Junjia Tang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Feiqiang Ma
- Department of Emergency Medicine, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Kun Pan
- Department of Neurosurgery, New York-Presbyterian Hospital, New York, NY, USA
| | - Mingfei Zhao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Anwen Shao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Qun Wu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China
| | - Yuan Hong
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
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Hossein-Javaheri N, Wilkie MP, Lado WE, Buck LT. Stellate and pyramidal neurons in goldfish telencephalon respond differently to anoxia and GABA receptor inhibition. J Exp Biol 2016; 220:695-704. [DOI: 10.1242/jeb.146605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/30/2016] [Indexed: 01/13/2023]
Abstract
With oxygen deprivation, the mammalian brain undergoes hyper-activity and neuronal death while this does not occur in the anoxia tolerant goldfish (Carassius auratus). Anoxic survival of the goldfish may rely on neuromodulatory mechanisms to suppress neuronal hyper-excitability. Since γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in brain, we decided to investigate its potential role in suppressing the electrical activity of goldfish telencephalic neurons. Utilizing whole-cell patch-clamp recording we recorded the electrical activities of both excitatory (pyramidal) and inhibitory (stellate) neurons. With anoxia, membrane potential (Vm) depolarized in both cell types from −72.2mV to −57.7mV and from −64.5mV to −46.8mV in pyramidal and stellate neurons, respectively. While pyramidal cells remained mostly quiescent, action potential frequency (APf) of the stellate neurons increased 68 fold. Furthermore, the GABAA receptor reversal potential (EGABA) was determined using the gramicidin perforated-patch clamp method and found to be depolarizing in pyramidal (−53.8mV) and stellate neurons (−42.1mV). Although GABA was depolarizing, pyramidal neurons remained quiescent since EGABA is below the action potential threshold (−36mV pyramidal and −38mV stellate neurons). Inhibition of GABAA receptors with gabazine reversed the anoxia mediated response. While GABAB receptor inhibition alone did not affect the anoxic response, co-antagonism of GABAA and GABAB receptors (gabazine and CGP-55848) lead to generation of seizure-like activities in both neuron types. We conclude that with anoxia Vm depolarizes towards EGABA which increases APf in stellate neurons and decreases APf in pyramidal neurons, and that GABA plays an important role in the anoxia-tolerance of goldfish brain.
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Affiliation(s)
- Nariman Hossein-Javaheri
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, ON, M5S 3G5, USA
| | - Michael P. Wilkie
- Department of Biology, Wilfred Laurier University, 75 University Avenue West, Waterloo, ON, N2L 3C5, USA
| | - Wudu E. Lado
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL, 35294-2182, USA
| | - Leslie T. Buck
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, ON, M5S 3G5, USA
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Chevy Q, Heubl M, Goutierre M, Backer S, Moutkine I, Eugène E, Bloch-Gallego E, Lévi S, Poncer JC. KCC2 Gates Activity-Driven AMPA Receptor Traffic through Cofilin Phosphorylation. J Neurosci 2015; 35:15772-86. [PMID: 26631461 PMCID: PMC6605455 DOI: 10.1523/jneurosci.1735-15.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 09/01/2015] [Accepted: 09/26/2015] [Indexed: 12/31/2022] Open
Abstract
Expression of the neuronal K/Cl transporter KCC2 is tightly regulated throughout development and by both normal and pathological neuronal activity. Changes in KCC2 expression have often been associated with altered chloride homeostasis and GABA signaling. However, recent evidence supports a role of KCC2 in the development and function of glutamatergic synapses through mechanisms that remain poorly understood. Here we show that suppressing KCC2 expression in rat hippocampal neurons precludes long-term potentiation of glutamatergic synapses specifically by preventing activity-driven membrane delivery of AMPA receptors. This effect is independent of KCC2 transporter function and can be accounted for by increased Rac1/PAK- and LIMK-dependent cofilin phosphorylation and actin polymerization in dendritic spines. Our results demonstrate that KCC2 plays a critical role in the regulation of spine actin cytoskeleton and gates long-term plasticity at excitatory synapses in cortical neurons.
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Affiliation(s)
- Quentin Chevy
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Martin Heubl
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Marie Goutierre
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Stéphanie Backer
- Institut Cochin, Institut National de la Santé et de la Recherche Médicale, U 1016, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8104, Université Paris Descartes, F-75014, Paris, France
| | - Imane Moutkine
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Emmanuel Eugène
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Evelyne Bloch-Gallego
- Institut Cochin, Institut National de la Santé et de la Recherche Médicale, U 1016, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8104, Université Paris Descartes, F-75014, Paris, France
| | - Sabine Lévi
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
| | - Jean Christophe Poncer
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche-S 839, F-75005, Paris, France, Institut du Fer a Moulin, F-75005, Paris, France, and
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Kim J, Son Y, Kim J, Lee S, Kang S, Park K, Kim SH, Kim JC, Kim J, Takayama C, Im HI, Yang M, Shin T, Moon C. Developmental and degenerative modulation of GABAergic transmission in the mouse hippocampus. Int J Dev Neurosci 2015; 47:320-32. [PMID: 26394279 DOI: 10.1016/j.ijdevneu.2015.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/05/2015] [Accepted: 08/21/2015] [Indexed: 11/30/2022] Open
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter involved in synaptic plasticity. GABAergic transmission is also implicated in developmental and degenerative processes in the brain. The goal of the present study was to understand the developmental and degenerative regulation of GABAergic transmission in the mouse hippocampus by examining changes in GABA receptor subunit mRNA levels and GABA-related protein expression during postnatal development of the hippocampus and trimethyltin (TMT)-induced neurodegeneration in the juvenile (postnatal day [PD] 24) and adult hippocampus (PD 56). During postnatal development, the mRNA levels of GABA A receptor (GABAAR) subunits, including α1, α4, β1, β2, and δ; GABA B receptor (GABABR) subunit 2; and the expression of GABA-related proteins, including glutamic acid decarboxylase, vesicular GABA transporter (VGAT), and potassium chloride cotransporter 2 increased gradually in the mouse hippocampus. The results of seizure scoring and histopathological findings in the hippocampus revealed a more pronounced response to the same administered TMT dose in juvenile mice, compared with that in adult mice. The mRNA levels of most GABA receptor subunits in the juvenile hippocampus, excluding GABAAR subunit β3, were dynamically altered after TMT treatment. The mRNA levels of GABAAR subunits γ2 and δ decreased significantly in the adult hippocampus following TMT treatment, whereas the level of GABABR subunit 1 mRNA increased significantly. Among the GABA-related proteins, only VGAT decreased significantly in the juvenile and adult mouse hippocampus after TMT treatment. In conclusion, regulation of GABAergic signaling in the mouse hippocampus may be related to maturation of the central nervous system and the degree of neurodegeneration during postnatal development and TMT-induced neurodegeneration in the experimental animals.
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Affiliation(s)
- Jinwook Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Yeonghoon Son
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Juhwan Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea; Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea
| | - Sueun Lee
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Sohi Kang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Kyunghwan Park
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea
| | - Jeongtae Kim
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - Heh-In Im
- Center for Neuroscience, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea
| | - Miyoung Yang
- Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, South Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 690-756, South Korea.
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju 500-757, South Korea.
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Mahadevan V, Dargaei Z, Ivakine EA, Hartmann AM, Ng D, Chevrier J, Ormond J, Nothwang HG, McInnes RR, Woodin MA. Neto2-null mice have impaired GABAergic inhibition and are susceptible to seizures. Front Cell Neurosci 2015; 9:368. [PMID: 26441539 PMCID: PMC4585209 DOI: 10.3389/fncel.2015.00368] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/04/2015] [Indexed: 11/27/2022] Open
Abstract
Neto2 is a transmembrane protein that interacts with the neuron-specific K+-Cl− cotransporter (KCC2) in the central nervous system (CNS). Efficient KCC2 transport is essential for setting the neuronal Cl− gradient, which is required for fast GABAergic inhibition. Neto2 is required to maintain the normal abundance of KCC2 in neurons, and increases KCC2 function by binding to the active oligomeric form of this cotransporter. In the present study, we characterized GABAergic inhibition and KCC2-mediated neuronal chloride homeostasis in pyramidal neurons from adult hippocampal slices. Using gramicidin perforated patch clamp recordings we found that the reversal potential for GABA (EGABA) was significantly depolarized. We also observed that surface levels of KCC2 and phosphorylation of KCC2 serine 940 (Ser940) were reduced in Neto2−/− neurons compared to wild-type controls. To examine GABAergic inhibition we recorded spontaneous inhibitory postsynaptic currents (sIPSCs) and found that Neto2−/− neurons had significant reductions in both their amplitude and frequency. Based on the critical role of Neto2 in regulating GABAergic inhibition we rationalized that Neto2-null mice would be prone to seizure activity. We found that Neto2-null mice demonstrated a decrease in the latency to pentylenetetrazole (PTZ)-induced seizures and an increase in seizure severity.
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Affiliation(s)
- Vivek Mahadevan
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Zahra Dargaei
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Evgueni A Ivakine
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children Research Institute Toronto, ON, Canada
| | - Anna-Maria Hartmann
- Department of Systematic and Evolutionary Biology, Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany
| | - David Ng
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children Research Institute Toronto, ON, Canada ; Departments of Neuroscience, Biochemistry and Molecular Biophysics, Columbia University New York City, NY, USA
| | - Jonah Chevrier
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
| | - Jake Ormond
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada ; RIKEN Brain Sciences Institute Tokyo, Japan
| | - Hans Gerd Nothwang
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany
| | - Roderick R McInnes
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children Research Institute Toronto, ON, Canada ; Departments of Human Genetics and Biochemistry, McGill University and Lady Davis Institute, Jewish General Hospital Montreal, QC, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
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Titz S, Sammler EM, Hormuzdi SG. Could tuning of the inhibitory tone involve graded changes in neuronal chloride transport? Neuropharmacology 2015; 95:321-31. [PMID: 25843644 DOI: 10.1016/j.neuropharm.2015.03.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 03/17/2015] [Accepted: 03/24/2015] [Indexed: 11/15/2022]
Abstract
Hyperpolarizing synaptic inhibition through GABAA and glycine receptors depends on the presence of the neuronal cation-chloride-cotransporter protein, KCC2. Several transcriptional and post-transcriptional mechanisms have been shown to regulate KCC2 and thereby influence the polarity and efficacy of inhibitory synaptic transmission. It is unclear however whether regulation of KCC2 enables the transporter to attain different levels of activity thus allowing a neuron to modulate the strength of inhibitory synaptic transmission to its changing requirements. We therefore investigated whether phosphorylation can allow KCC2 to achieve distinct levels of [Cl(-)]i in neurons. We generated a variety of KCC2 alanine dephosphorylation mimics and used NH4(+)-induced pHi shifts in cultured hippocampal neurons to quantify the rate of KCC2 transport activity exhibited by these mutants. To explore the relationship between KCC2 transport and GABAA receptor-mediated current amplitudes we performed gramicidine perforated-patch recordings. The correlation between EGABA and NH4(+)-induced pHi shifts enabled an estimate of the range of chloride extrusion possible by kinase/phosphatase regulation of KCC2. Our results demonstrate that KCC2 transport can vary considerably in magnitude depending on the combination of alanine mutations present on the protein. Transport can be enhanced to sufficiently high levels that hyperpolarizing GABAA responses may be obtained even in neurons with an extremely negative resting membrane potential and at high extracellular K(+) concentrations. Our findings highlight the significant potential for regulating the inhibitory tone by KCC2-mediated chloride extrusion and suggest that cellular signaling pathways may act combinatorially to alter KCC2 phosphorylation/dephosphorylation and thereby tune the strength of synaptic inhibition.
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Affiliation(s)
- Stefan Titz
- Institute for Physiology und Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany.
| | - Esther M Sammler
- Division of Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Sheriar G Hormuzdi
- Division of Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK.
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42
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Hogg DW, Pamenter ME, Dukoff DJ, Buck LT. Decreases in mitochondrial reactive oxygen species initiate GABA(A) receptor-mediated electrical suppression in anoxia-tolerant turtle neurons. J Physiol 2015; 593:2311-26. [PMID: 25781154 DOI: 10.1113/jp270474] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 03/12/2015] [Indexed: 12/16/2022] Open
Abstract
Anoxia induces hyper-excitability and cell death in mammalian brain but in the anoxia-tolerant western painted turtle (Chrysemys picta bellii) neuronal electrical activity is suppressed (i.e. spike arrest), adenosine triphosphate (ATP) consumption is reduced, and cell death does not occur. Electrical suppression is primarily the result of enhanced γ-aminobutyric acid (GABA) transmission; however, the underlying mechanism responsible for initiating oxygen-sensitive GABAergic spike arrest is unknown. In turtle cortical pyramidal neurons there are three types of GABA(A) receptor-mediated currents: spontaneous inhibitory postsynaptic currents (IPSCs), giant IPSCs and tonic currents. The aim of this study was to assess the effects of reactive oxygen species (ROS) scavenging on these three currents since ROS levels naturally decrease with anoxia and may serve as a redox signal to initiate spike arrest. We found that anoxia, pharmacological ROS scavenging, or inhibition of mitochondrial ROS generation enhanced all three types of GABA currents, with tonic currents comprising ∼50% of the total current. Application of hydrogen peroxide inhibited all three GABA currents, demonstrating a reversible redox-sensitive signalling mechanism. We conclude that anoxia-mediated decreases in mitochondrial ROS production are sufficient to initiate a redox-sensitive inhibitory GABA signalling cascade that suppresses electrical activity when oxygen is limited. This unique strategy for reducing neuronal ATP consumption during anoxia represents a natural mechanism in which to explore therapies to protect mammalian brain from low-oxygen insults.
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Affiliation(s)
- David W Hogg
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
| | - Matthew E Pamenter
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - David J Dukoff
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
| | - Leslie T Buck
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5.,Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
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43
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Blaesse P, Schmidt T. K-Cl cotransporter KCC2--a moonlighting protein in excitatory and inhibitory synapse development and function. Pflugers Arch 2015; 467:615-24. [PMID: 24909111 DOI: 10.1007/s00424-014-1547-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 05/23/2014] [Accepted: 05/26/2014] [Indexed: 01/28/2023]
Abstract
The K-Cl cotransporter KCC2 has two entirely independent biological actions as either an ion transporter or a structural protein orchestrating the organization of the cytoskeleton in neuronal structures. The K-Cl cotransport by KCC2 is central for hyperpolarizing inhibitory signaling, which is based on chloride currents mediated by γ-aminobutyric acid (GABA)- or glycine-gated receptor channels. In contrast, the structural role of KCC2 seems to be crucially involved in the maturation and regulation of excitatory glutamatergic synapses. This dual role at GABAergic/glycinergic and glutamatergic synapses makes KCC2 a key molecule in the regulation of inhibitory and excitatory signaling. Therefore, KCC2 is most likely involved in the synchronization of the two types of activity during network formation in the immature system and a similar synchronizing role might also be important under physiological and pathological conditions in mature neuronal networks. In this review, we explore new findings on the regulation of KCC2 by protease-mediated cleavage and on the structural role of KCC2 in spine morphogenesis and glutamate receptor clustering. We then discuss the implications of the putative interaction between the independent functions of the transporter and overlapping regulatory mechanisms in a neurophysiological context. In addition, we look at the multifunctional properties of KCC2 in the light of evolution and propose that KCC2 belongs to the group of moonlighting (multifunctional) proteins.
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Affiliation(s)
- Peter Blaesse
- Institute of Physiology I (Neurophysiology), Westfälische Wilhelms-University Münster, Robert-Koch-Strasse 27a, 48149, Münster, Germany,
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44
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Hartmann AM, Nothwang HG. Molecular and evolutionary insights into the structural organization of cation chloride cotransporters. Front Cell Neurosci 2015; 8:470. [PMID: 25653592 PMCID: PMC4301019 DOI: 10.3389/fncel.2014.00470] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/30/2014] [Indexed: 01/26/2023] Open
Abstract
Cation chloride cotransporters (CCC) play an essential role for neuronal chloride homeostasis. K(+)-Cl(-) cotransporter (KCC2), is the principal Cl(-)-extruder, whereas Na(+)-K(+)-Cl(-) cotransporter (NKCC1), is the major Cl(-)-uptake mechanism in many neurons. As a consequence, the action of the inhibitory neurotransmitters gamma-aminobutyric acid (GABA) and glycine strongly depend on the activity of these two transporters. Knowledge of the mechanisms involved in ion transport and regulation is thus of great importance to better understand normal and disturbed brain function. Although no overall 3-dimensional crystal structures are yet available, recent molecular and phylogenetic studies and modeling have provided new and exciting insights into structure-function relationships of CCC. Here, we will summarize our current knowledge of the gross structural organization of the proteins, their functional domains, ion binding and translocation sites, and the established role of individual amino acids (aa). A major focus will be laid on the delineation of shared and distinct organizational principles between KCC2 and NKCC1. Exploiting the richness of recently generated genome data across the tree of life, we will also explore the molecular evolution of these features.
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Affiliation(s)
- Anna-Maria Hartmann
- Systematics and Evolutionary Biology Group, Institute for Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany
| | - Hans Gerd Nothwang
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany ; Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg Oldenburg, Germany
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45
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Watanabe M, Fukuda A, Nabekura J. The role of GABA in the regulation of GnRH neurons. Front Neurosci 2014; 8:387. [PMID: 25506316 PMCID: PMC4246667 DOI: 10.3389/fnins.2014.00387] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 11/12/2014] [Indexed: 11/13/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) neurons form the final common pathway for the central regulation of reproduction. Gamma-amino butyric acid (GABA) has long been implicated as one of the major players in the regulation of GnRH neurons. Although GABA is typically an inhibitory neurotransmitter in the mature adult central nervous system, most mature GnRH neurons show the unusual characteristic of being excited by GABA. While many reports have provided much insight into the contribution of GABA to the activity of GnRH neurons, the precise physiological role of the excitatory action of GABA on GnRH neurons remains elusive. This brief review presents the current knowledge of the role of GABA signaling in GnRH neuronal activity. We also discuss the modulation of GABA signaling by neurotransmitters and neuromodulators and the functional consequence of GABAergic inputs to GnRH neurons in both the physiology and pathology of reproduction.
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Affiliation(s)
- Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine Hamamatsu, Japan
| | - Junichi Nabekura
- Department of Developmental Physiology, National Institute for Physiological Sciences Okazaki, Japan ; Core Research for Evolutionary Science and Technology, Japan Science and Technology Corporation Saitama, Japan ; Department of Physiological Sciences, The Graduate School for Advanced Study Hayama, Japan
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46
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Weber M, Hartmann AM, Beyer T, Ripperger A, Nothwang HG. A novel regulatory locus of phosphorylation in the C terminus of the potassium chloride cotransporter KCC2 that interferes with N-ethylmaleimide or staurosporine-mediated activation. J Biol Chem 2014; 289:18668-79. [PMID: 24849604 PMCID: PMC4081912 DOI: 10.1074/jbc.m114.567834] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/15/2014] [Indexed: 11/06/2022] Open
Abstract
The neuron-specific cation chloride cotransporter KCC2 plays a crucial role in hyperpolarizing synaptic inhibition. Transporter dysfunction is associated with various neurological disorders, raising interest in regulatory mechanisms. Phosphorylation has been identified as a key regulatory process. Here, we retrieved experimentally observed phosphorylation sites of KCC2 from public databases and report on the systematic analysis of six phosphorylated serines, Ser(25), Ser(26), Ser(937), Ser(1022), Ser(1025), and Ser(1026). Alanine or aspartate substitutions of these residues were analyzed in HEK-293 cells. All mutants were expressed in a pattern similar to wild-type KCC2 (KCC2(WT)). Tl(+) flux measurements demonstrated unchanged transport activity for Ser(25), Ser(26), Ser(1022), Ser(1025), and Ser(1026) mutants. In contrast, KCC2(S937D), mimicking phosphorylation, resulted in a significant up-regulation of transport activity. Aspartate substitution of Thr(934), a neighboring putative phosphorylation site, resulted in a comparable increase in KCC2 transport activity. Both KCC2(T934D) and KCC2(S937D) mutants were inhibited by the kinase inhibitor staurosporine and by N-ethylmaleimide, whereas KCC2(WT), KCC2(T934A), and KCC2(S937A) were activated. The inverse staurosporine effect on aspartate versus alanine substitutions reveals a cross-talk between different phosphorylation sites of KCC2. Immunoblot and cell surface labeling experiments detected no alterations in total abundance or surface expression of KCC2(T934D) and KCC2(S937D) compared with KCC2(WT). These data reveal kinetic regulation of transport activity by these residues. In summary, our data identify a novel key regulatory phosphorylation site of KCC2 and a functional interaction between different conformation-changing post-translational modifications. The action of pharmacological agents aimed to modulate KCC2 activity for therapeutic benefit might therefore be highly context-specific.
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Affiliation(s)
- Maren Weber
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences
| | - Anna-Maria Hartmann
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Systematics and Evolutionary Biology Group, Institute for Biology and Environmental Sciences, and
| | - Timo Beyer
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences
| | - Anne Ripperger
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences
| | - Hans Gerd Nothwang
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, the Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
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47
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Mahadevan V, Pressey JC, Acton BA, Uvarov P, Huang MY, Chevrier J, Puchalski A, Li CM, Ivakine EA, Airaksinen MS, Delpire E, McInnes RR, Woodin MA. Kainate receptors coexist in a functional complex with KCC2 and regulate chloride homeostasis in hippocampal neurons. Cell Rep 2014; 7:1762-70. [PMID: 24910435 PMCID: PMC6340141 DOI: 10.1016/j.celrep.2014.05.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 03/31/2014] [Accepted: 05/09/2014] [Indexed: 12/01/2022] Open
Abstract
KCC2 is the neuron-specific K+-Cl(-) cotransporter required for maintaining low intracellular Cl(-), which is essential for fast inhibitory synaptic transmission in the mature CNS. Despite the requirement of KCC2 for inhibitory synaptic transmission, understanding of the cellular mechanisms that regulate KCC2 expression and function is rudimentary. We examined KCC2 in its native protein complex in vivo to identify key KCC2-interacting partners that regulate KCC2 function. Using blue native-polyacrylamide gel electrophoresis (BN-PAGE), we determined that native KCC2 exists in a macromolecular complex with kainate-type glutamate receptors (KARs). We found that KAR subunits are required for KCC2 oligomerization and surface expression. In accordance with this finding, acute and chronic genetic deletion of KARs decreased KCC2 function and weakened synaptic inhibition in hippocampal neurons. Our results reveal KARs as regulators of KCC2, significantly advancing our growing understanding of the tight interplay between excitation and inhibition.
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Affiliation(s)
- Vivek Mahadevan
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Jessica C Pressey
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Brooke A Acton
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Pavel Uvarov
- Institute of Biomedicine, Anatomy, University of Helsinki, 00014 Helsinki, Finland
| | - Michelle Y Huang
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Jonah Chevrier
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Andrew Puchalski
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Caiwei M Li
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Evgueni A Ivakine
- Hospital for Sick Children Research Institute, Toronto, ON M5G 1X8, Canada
| | - Matti S Airaksinen
- Institute of Biomedicine, Anatomy, University of Helsinki, 00014 Helsinki, Finland
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Roderick R McInnes
- Hospital for Sick Children Research Institute, Toronto, ON M5G 1X8, Canada; Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, QC H3T 1E2, Canada
| | - Melanie A Woodin
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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48
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Bergeron MJ, Castonguay A, De Koninck Y. [KCC2: a new therapeutical target for the treatment of neurological diseases]. Med Sci (Paris) 2014; 30:514-7. [PMID: 24939537 DOI: 10.1051/medsci/20143005013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Affiliation(s)
- Marc J Bergeron
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, 2601, de la Canardière, G1J 2G3 Québec, Canada
| | - Annie Castonguay
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, 2601, de la Canardière, G1J 2G3 Québec, Canada
| | - Yves De Koninck
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, 2601, de la Canardière, G1J 2G3 Québec, Canada
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49
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Medina I, Friedel P, Rivera C, Kahle KT, Kourdougli N, Uvarov P, Pellegrino C. Current view on the functional regulation of the neuronal K(+)-Cl(-) cotransporter KCC2. Front Cell Neurosci 2014; 8:27. [PMID: 24567703 PMCID: PMC3915100 DOI: 10.3389/fncel.2014.00027] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/18/2014] [Indexed: 12/22/2022] Open
Abstract
In the mammalian central nervous system (CNS), the inhibitory strength of chloride (Cl(-))-permeable GABAA and glycine receptors (GABAAR and GlyR) depends on the intracellular Cl(-) concentration ([Cl(-)]i). Lowering [Cl(-)]i enhances inhibition, whereas raising [Cl(-)]i facilitates neuronal activity. A neuron's basal level of [Cl(-)]i, as well as its Cl(-) extrusion capacity, is critically dependent on the activity of the electroneutral K(+)-Cl(-) cotransporter KCC2, a member of the SLC12 cation-Cl(-) cotransporter (CCC) family. KCC2 deficiency compromises neuronal migration, formation and the maturation of GABAergic and glutamatergic synaptic connections, and results in network hyperexcitability and seizure activity. Several neurological disorders including multiple epilepsy subtypes, neuropathic pain, and schizophrenia, as well as various insults such as trauma and ischemia, are associated with significant decreases in the Cl(-) extrusion capacity of KCC2 that result in increases of [Cl(-)]i and the subsequent hyperexcitability of neuronal networks. Accordingly, identifying the key upstream molecular mediators governing the functional regulation of KCC2, and modifying these signaling pathways with small molecules, might constitute a novel neurotherapeutic strategy for multiple diseases. Here, we discuss recent advances in the understanding of the mechanisms regulating KCC2 activity, and of the role these mechanisms play in neuronal Cl(-) homeostasis and GABAergic neurotransmission. As KCC2 mediates electroneutral transport, the experimental recording of its activity constitutes an important research challenge; we therefore also, provide an overview of the different methodological approaches utilized to monitor function of KCC2 in both physiological and pathological conditions.
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Affiliation(s)
- Igor Medina
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
- Aix-Marseille Université, UMR901Marseille, France
| | - Perrine Friedel
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
- Aix-Marseille Université, UMR901Marseille, France
| | - Claudio Rivera
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
- Aix-Marseille Université, UMR901Marseille, France
- Neuroscience Center, University of HelsinkiHelsinki, Finland
| | - Kristopher T. Kahle
- Department of Cardiology, Manton Center for Orphan Disease Research, Howard Hughes Medical Institute, Boston Children's HospitalBoston, MA, USA
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical SchoolBoston, MA, USA
| | - Nazim Kourdougli
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
- Aix-Marseille Université, UMR901Marseille, France
| | - Pavel Uvarov
- Institute of Biomedicine, Anatomy, University of HelsinkiHelsinki, Finland
| | - Christophe Pellegrino
- INSERM, Institut de Neurobiologie de la Méditerranée (INMED)Marseille, France
- Aix-Marseille Université, UMR901Marseille, France
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50
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Kahle KT, Deeb TZ, Puskarjov M, Silayeva L, Liang B, Kaila K, Moss SJ. Modulation of neuronal activity by phosphorylation of the K-Cl cotransporter KCC2. Trends Neurosci 2013; 36:726-737. [PMID: 24139641 PMCID: PMC4381966 DOI: 10.1016/j.tins.2013.08.006] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/19/2013] [Accepted: 08/26/2013] [Indexed: 12/29/2022]
Abstract
The K-Cl cotransporter KCC2 establishes the low intraneuronal Cl- levels required for the hyperpolarizing inhibitory postsynaptic potentials mediated by ionotropic γ-aminobutyric acid receptors (GABAARs) and glycine receptors (GlyRs). Decreased KCC2-mediated Cl- extrusion and impaired hyperpolarizing GABAAR- and/or GlyR-mediated currents have been implicated in epilepsy, neuropathic pain, and spasticity. Recent evidence suggests that the intrinsic ion transport rate, cell surface stability, and plasmalemmal trafficking of KCC2 are rapidly and reversibly modulated by the (de)phosphorylation of critical serine, threonine, and tyrosine residues in the C terminus of this protein. Alterations in KCC2 phosphorylation have been associated with impaired KCC2 function in several neurological diseases. Targeting KCC2 phosphorylation directly or indirectly via upstream regulatory kinases might be a novel strategy to modulate GABA- and/or glycinergic signaling for therapeutic benefit.
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Affiliation(s)
- Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Howard Hughes Medical Institute, Department of Cardiology, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Liliya Silayeva
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Bo Liang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Neuroscience, Physiology and Pharmacology, University College, London, WC1E 6BT, UK
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